|
|
|
|
|
|
|
|
|
|
|
|
资助项目
GST,p < 0.001) and low levels of seed-based gene flow. C. debaoensis (Cycadaceae) is an endangered species restricted to the border of Guangxi and Yunnan province in southwest China. This species has been classified into two types: sand and karst, according to the soil matrix they grow on. We examined chloroplast sequence variation of the cpDNA sequences from 11 populations of this species. Significant population genetic differentiation was detected (GST= 0.684 and FST = 0.74160). There was marked genetic differentiation between populations in the sand and karst regions and no expansion was detected. Climate changes during glacial periods have had significant effects on the current distribution of cycads. The molecular phylogenetic data, together with the geographic distribution of the haplotypes, suggest that C. debaoensis experienced range contraction during glacial periods, and that the current populations are still confined to the original refugia in southwest China which have favorable habitats in glacial period. These results imply that small refugia were maintained in both sand and karst regions during the LGM (last glacial maximum). This species had no postglacial recolonization and only stayed in these refugia up to now. The low within-population diversity of C. debaoensis suggests that there were strong bottleneck events or founder effects within each separate region during the Quaternary climatic oscillations. Relatively high genetic and haplotype diversities were detected in the newly discovered populations, which located at intermediate locality of sand regions and had morphological variation; this is probably the consequence of the admixture of different haplotypes colonizing the area from separate sources. C. micholitzii occurs in the Annan Highlands in central Vietnam near the Laos border. C. bifida occurs in North Vietnam; its distribution extends across the border into adjacent localities in Guangxi and Yunnan in China. For the comparability between them,theywere considered as the same species C. micholitzii by many academicians. The cpDNA sequences from 11 populations showed that these very controversial species, C. micholitzii and C. bifida, is paraphyletic and should belong to the same species C. micholitzii. AMOVA analysis showed that the component of among-population within region/species (76.46%) was unexpectedly larger than the among-species/region component (14.97%), which also indicates that there is no justification for recognizing two species as C. micholitzii and C. bifida. This hypothesis was also supported by the geological data, especially the neotectonic history of the indo-china block, which started to move south since Oligocene and cause the geographic isolation of these two groups. Therefore, the most likely explanation to the phenotypic similarities between these two groups may be the retention of ancestral polymorphisms in the paraphyletic group due to incomplete lineage sorting. Furthermore, the similarities may also be ascribed to pollen-mediated gene flow among geographically proximate populations and/or phenotypic convergence under similar selection schemes in the same region. C.micholitzi had the higest genetic diversity (HT = 0.980,) and genetic differentiation (GST = 0.830, NST = 0.915) among the C. micholitzii complex. The high genetic diversity might be attributed to its long evolutionary history, highly diverse habitats. The ineffective mode of seed dispersal and dramatic neotectonic movement in the distribution range of this species could result in the high genetic differentiation. 2. Phylogeographic analysis based on nuclear ribosomal sequences, We sequenced the nrDNA ITS in all 27 populations sampled, 7 haplotypes were identified, among which C. micholitzii had 6, while C. multipinnata, C. longipetiolula and C. debaoensis shared the remaining one. Compared to chloroplast genes, nuclear genes had higher correlation between genetic and geographical distance, but lower interspecies differentiation (54.42% vs 25.24%). Phylogeographical structure of C. micholitzii and C.bifida based on ITS Variation was consistent with the morphology differentiation. This similar in nuclear gene should be ascribed to pollen-mediated gene flow among geographically proximate populations.Long-distance gene flow over the two groups was clearly interrupted, which brought on the nrDNA genetic differenciation between the geographically isolated groups, to a certain extent affected the morphological variation. 3. Interspecies relationships among Cycas micholitzii complex, We analysed chloroplast sequence variation of the atpB-rbcL and psbA-trnH intergenic spacers in 27 populations sampled of C. micholitzii complex, AMOVA analysis showed that the component of among-species/region component (59.21%). However, phylogenic analysis showed that the haplotypes of C. micholitzii complex couldn`t grouped into four clusters closely corresponding to the narrowly defined C. micholitzi, C. multipinnata, C. debaoensis and C. longipetiolula. We concluded that the conflict may result from several factors: firstly incomplete lineage sorting of C. micholitzii; secondly hybridization/introgression of sympatrically cycads, which would be supported by evidence base on nrDNA ITS sequences; thirdly intramolecular recombination in cpDNA of cycads; eventually the neotectonic movement in the distribution range of this species.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ACycas%5C+micholitzii%5C+complex%5C+is%5C+composed%5C+of%5C+5%5C+species%5C%3A%5C+C.%5C+micholitzii%5C+Dyer%2C%5C+C.%5C+bifida%5C+%5C%28Dyer%5C%29%5C+K.%5C+D.%5C+Hill%2CC.%5C+longipetiolula%5C+D.%5C+Y.%5C+Wang%2C%5C+C.%5C+debaoensis%5C+Y.%5C+C.%5C+Zhong%5C+et%5C+C%5C+J.%5C+Chen%2C%5C+C.%5C+multipinnata%5C+C%5C+J.%5C+Chen%5C+et%5C+S.%5C+Y.%5C+Yang%EF%BC%8Cand%5C+distributed%5C+from%5C+southwest%5C+China%5C+to%5C+central%5C+Vietnam%5C+and%5C+eastern%5C+Laos.%5C+Based%5C+on%5C+sequence%5C+data%5C+from%5C+two%5C+maternally%5C+inherited%5C+cpDNA%5C+and%5C+one%5C+biparentally%5C+nuclear%5C+DNA%5C+fragments%2C%5C+our%5C+study%5C+revealed%5C+the%5C+population%5C+genetic%5C+structure%5C+of%5C+C.%5C+micholitzii%5C+complex%5C+and%5C+explored%5C+the%5C+potential%5C+causes.%5C+The%5C+evolutionary%5C+and%5C+demographic%5C+histories%5C+were%5C+investigated.%5C+The%5C+genetic%5C+relationship%5C+among%5C+species%5C+in%5C+the%5C+complex%5C+was%5C+also%5C+clarified.The%5C+results%5C+were%5C+summarized%5C+as%5C+follows%5C%3A%5C+1.%5C+Phylogeographic%5C+analysis%5C+based%5C+on%5C+chloroplast%5C+sequences%EF%BC%8CWe%5C+examined%5C+chloroplast%5C+sequence%5C+variation%5C+of%5C+the%5C+atpB%5C-rbcLand%5C+psbA%5C-trnHintergenic%5C+spacers%5C+in%5C+27%5C+populations%5C+of%5C+C.%5C+micholitzii%5C+complex%2C%5C+recovering%5C+26%5C+haplotypes.%5C+The%5C+average%5C+within%5C-population%5C+diversity%5C+%5C%28HS%5C+%3D%5C+0.140%5C%29%5C+was%5C+low%5C+while%5C+total%5C+diversity%5C+%5C%28HT%5C+%3D%5C+0.911%5C%29%5C+was%5C+high.%5C+Population%5C+differentiation%5C+was%5C+also%5C+high%5C%28GST%5C+%3D%5C+0.846%2C%5C+NST%5C+%3D%5C+0.919%5C%29%2C%5C+indicating%5C+significant%5C+phylogeographical%5C+structure%5C+%5C%28NST%5C+%3E%5C+GST%2Cp%5C+%3C%5C+0.001%5C%29%5C+and%5C+low%5C+levels%5C+of%5C+seed%5C-based%5C+gene%5C+flow.%5C+C.%5C+debaoensis%5C+%5C%28Cycadaceae%5C%29%5C+is%5C+an%5C+endangered%5C+species%5C+restricted%5C+to%5C+the%5C+border%5C+of%5C+Guangxi%5C+and%5C+Yunnan%5C+province%5C+in%5C+southwest%5C+China.%5C+This%5C+species%5C+has%5C+been%5C+classified%5C+into%5C+two%5C+types%5C%3A%5C+sand%5C+and%5C+karst%2C%5C+according%5C+to%5C+the%5C+soil%5C+matrix%5C+they%5C+grow%5C+on.%5C+We%5C+examined%5C+chloroplast%5C+sequence%5C+variation%5C+of%5C+the%5C+cpDNA%5C+sequences%5C+from%5C+11%5C+populations%5C+of%5C+this%5C+species.%5C+Significant%5C+population%5C+genetic%5C+differentiation%5C+was%5C+detected%5C+%5C%28GST%3D%5C+0.684%5C+and%5C+FST%5C+%3D%5C+0.74160%5C%29.%5C+There%5C+was%5C+marked%5C+genetic%5C+differentiation%5C+between%5C+populations%5C+in%5C+the%5C+sand%5C+and%5C+karst%5C+regions%5C+and%5C+no%5C+expansion%5C+was%5C+detected.%5C+Climate%5C+changes%5C+during%5C+glacial%5C+periods%5C+have%5C+had%5C+significant%5C+effects%5C+on%5C+the%5C+current%5C+distribution%5C+of%5C+cycads.%5C+The%5C+molecular%5C+phylogenetic%5C+data%2C%5C+together%5C+with%5C+the%5C+geographic%5C+distribution%5C+of%5C+the%5C+haplotypes%2C%5C+suggest%5C+that%5C+C.%5C+debaoensis%5C+experienced%5C+range%5C+contraction%5C+during%5C+glacial%5C+periods%2C%5C+and%5C+that%5C+the%5C+current%5C+populations%5C+are%5C+still%5C+confined%5C+to%5C+the%5C+original%5C+refugia%5C+in%5C+southwest%5C+China%5C+which%5C+have%5C+favorable%5C+habitats%5C+in%5C+glacial%5C+period.%5C+These%5C+results%5C+imply%5C+that%5C+small%5C+refugia%5C+were%5C+maintained%5C+in%5C+both%5C+sand%5C+and%5C+karst%5C+regions%5C+during%5C+the%5C+LGM%5C+%5C%28last%5C+glacial%5C+maximum%5C%29.%5C+This%5C+species%5C+had%5C+no%5C+postglacial%5C+recolonization%5C+and%5C+only%5C+stayed%5C+in%5C+these%5C+refugia%5C+up%5C+to%5C+now.%5C+The%5C+low%5C+within%5C-population%5C+diversity%5C+of%5C+C.%5C+debaoensis%5C+suggests%5C+that%5C+there%5C+were%5C+strong%5C+bottleneck%5C+events%5C+or%5C+founder%5C+effects%5C+within%5C+each%5C+separate%5C+region%5C+during%5C+the%5C+Quaternary%5C+climatic%5C+oscillations.%5C+Relatively%5C+high%5C+genetic%5C+and%5C+haplotype%5C+diversities%5C+were%5C+detected%5C+in%5C+the%5C+newly%5C+discovered%5C+populations%2C%5C+which%5C+located%5C+at%5C+intermediate%5C+locality%5C+of%5C+sand%5C+regions%5C+and%5C+had%5C+morphological%5C+variation%5C%3B%5C+this%5C+is%5C+probably%5C+the%5C+consequence%5C+of%5C+the%5C+admixture%5C+of%5C+different%5C+haplotypes%5C+colonizing%5C+the%5C+area%5C+from%5C+separate%5C+sources.%5C+%5C+C.%5C+micholitzii%5C+occurs%5C+in%5C+the%5C+Annan%5C+Highlands%5C+in%5C+central%5C+Vietnam%5C+near%5C+the%5C+Laos%5C+border.%5C+C.%5C+bifida%5C+occurs%5C+in%5C+North%5C+Vietnam%5C%3B%5C+its%5C+distribution%5C+extends%5C+across%5C+the%5C+border%5C+into%5C+adjacent%5C+localities%5C+in%5C+Guangxi%5C+and%5C+Yunnan%5C+in%5C+China.%5C+For%5C+the%5C+comparability%5C+between%5C+them%2Ctheywere%5C+considered%5C+as%5C+the%5C+same%5C+species%5C+C.%5C+micholitzii%5C+by%5C+many%5C+academicians.%5C+The%5C+cpDNA%5C+sequences%5C+from%5C+11%5C+populations%5C+showed%5C+that%5C+these%5C+very%5C+controversial%5C+species%2C%5C+C.%5C+micholitzii%5C+and%5C+C.%5C+bifida%2C%5C+is%5C+paraphyletic%5C+and%5C+should%5C+belong%5C+to%5C+the%5C+same%5C+species%5C+C.%5C+micholitzii.%5C+AMOVA%5C+analysis%5C+showed%5C+that%5C+the%5C+component%5C+of%5C+among%5C-population%5C+within%5C+region%5C%2Fspecies%5C+%5C%2876.46%25%5C%29%5C+was%5C+unexpectedly%5C+larger%5C+than%5C+the%5C+among%5C-species%5C%2Fregion%5C+component%5C+%5C%2814.97%25%5C%29%2C%5C+which%5C+also%5C+indicates%5C+that%5C+there%5C+is%5C+no%5C+justification%5C+for%5C+recognizing%5C+two%5C+species%5C+as%5C+C.%5C+micholitzii%5C+and%5C+C.%5C+bifida.%5C+This%5C+hypothesis%5C+was%5C+also%5C+supported%5C+by%5C+the%5C+geological%5C+data%2C%5C+especially%5C+the%5C+neotectonic%5C+history%5C+of%5C+the%5C+indo%5C-china%5C+block%2C%5C+which%5C+started%5C+to%5C+move%5C+south%5C+since%5C+Oligocene%5C+and%5C+cause%5C+the%5C+geographic%5C+isolation%5C+of%5C+these%5C+two%5C+groups.%5C+Therefore%2C%5C+the%5C+most%5C+likely%5C+explanation%5C+to%5C+the%5C+phenotypic%5C+similarities%5C+between%5C+these%5C+two%5C+groups%5C+may%5C+be%5C+the%5C+retention%5C+of%5C+ancestral%5C+polymorphisms%5C+in%5C+the%5C+paraphyletic%5C+group%5C+due%5C+to%5C+incomplete%5C+lineage%5C+sorting.%5C+Furthermore%2C%5C+the%5C+similarities%5C+may%5C+also%5C+be%5C+ascribed%5C+to%5C+pollen%5C-mediated%5C+gene%5C+flow%5C+among%5C+geographically%5C+proximate%5C+populations%5C+and%5C%2For%5C+phenotypic%5C+convergence%5C+under%5C+similar%5C+selection%5C+schemes%5C+in%5C+the%5C+same%5C+region.%5C+C.micholitzi%5C+had%5C+the%5C+higest%5C+genetic%5C+diversity%5C+%5C%28HT%5C+%3D%5C+0.980%2C%5C%29%5C+and%5C+genetic%5C+differentiation%5C+%5C%28GST%5C+%3D%5C+0.830%2C%5C+NST%5C+%3D%5C+0.915%5C%29%5C+among%5C+the%5C+C.%5C+micholitzii%5C+complex.%5C+The%5C+high%5C+genetic%5C+diversity%5C+might%5C+be%5C+attributed%5C+to%5C+its%5C+long%5C+evolutionary%5C+history%2C%5C+highly%5C+diverse%5C+habitats.%5C+The%5C+ineffective%5C+mode%5C+of%5C+seed%5C+dispersal%5C+and%5C+dramatic%5C+neotectonic%5C+movement%5C+in%5C+the%5C+distribution%5C+range%5C+of%5C+this%5C+species%5C+could%5C+result%5C+in%5C+the%5C+high%5C+genetic%5C+differentiation.%5C+2.%5C+Phylogeographic%5C+analysis%5C+based%5C+on%5C+nuclear%5C+ribosomal%5C+sequences%2C%5C+We%5C+sequenced%5C+the%5C+nrDNA%5C+ITS%5C+in%5C+all%5C+27%5C+populations%5C+sampled%2C%5C+7%5C+haplotypes%5C+were%5C+identified%2C%5C+among%5C+which%5C+C.%5C+micholitzii%5C+had%5C+6%2C%5C+while%5C+C.%5C+multipinnata%2C%5C+C.%5C+longipetiolula%5C+and%5C+C.%5C+debaoensis%5C+shared%5C+the%5C+remaining%5C+one.%5C+Compared%5C+to%5C+chloroplast%5C+genes%2C%5C+nuclear%5C+genes%5C+had%5C+higher%5C+correlation%5C+between%5C+genetic%5C+and%5C+geographical%5C+distance%2C%5C+but%5C+lower%5C+interspecies%5C+differentiation%5C+%5C%2854.42%25%5C+vs%5C+25.24%25%5C%29.%5C+Phylogeographical%5C+structure%5C+of%5C+C.%5C+micholitzii%5C+and%5C+C.bifida%5C+based%5C+on%5C+ITS%5C+Variation%5C+was%5C+consistent%5C+with%5C+the%5C+morphology%5C+differentiation.%5C+This%5C+similar%5C+in%5C+nuclear%5C+gene%5C+should%5C+be%5C+ascribed%5C+to%5C+pollen%5C-mediated%5C+gene%5C+flow%5C+among%5C+geographically%5C+proximate%5C+populations.Long%5C-distance%5C+gene%5C+flow%5C+over%5C+the%5C+two%5C+groups%5C+was%5C+clearly%5C+interrupted%2C%5C+which%5C+brought%5C+on%5C+the%5C+nrDNA%5C+genetic%5C+differenciation%5C+between%5C+the%5C+geographically%5C+isolated%5C+groups%2C%5C+to%5C+a%5C+certain%5C+extent%5C+affected%5C+the%5C+morphological%5C+variation.%5C+3.%5C+Interspecies%5C+relationships%5C+among%5C+Cycas%5C+micholitzii%5C+complex%2C%5C+We%5C+analysed%5C+chloroplast%5C+sequence%5C+variation%5C+of%5C+the%5C+atpB%5C-rbcL%5C+and%5C+psbA%5C-trnH%5C+intergenic%5C+spacers%5C+in%5C+27%5C+populations%5C+sampled%5C+of%5C+C.%5C+micholitzii%5C+complex%2C%5C+AMOVA%5C+analysis%5C+showed%5C+that%5C+the%5C+component%5C+of%5C+among%5C-species%5C%2Fregion%5C+component%5C+%5C%2859.21%25%5C%29.%5C+However%2C%5C+phylogenic%5C+analysis%5C+showed%5C+that%5C+the%5C+haplotypes%5C+of%5C+C.%5C+micholitzii%5C+complex%5C+couldn%60t%5C+grouped%5C+into%5C+four%5C+clusters%5C+closely%5C+corresponding%5C+to%5C+the%5C+narrowly%5C+defined%5C+C.%5C+micholitzi%2C%5C+C.%5C+multipinnata%2C%5C+C.%5C+debaoensis%5C+and%5C+C.%5C+longipetiolula.%5C+We%5C+concluded%5C+that%5C+the%5C+conflict%5C+may%5C+result%5C+from%5C+several%5C+factors%5C%3A%5C+firstly%5C+incomplete%5C+lineage%5C+sorting%5C+of%5C+C.%5C+micholitzii%5C%3B%5C+secondly%5C+hybridization%5C%2Fintrogression%5C+of%5C+sympatrically%5C+cycads%2C%5C+which%5C+would%5C+be%5C+supported%5C+by%5C+evidence%5C+base%5C+on%5C+nrDNA%5C+ITS%5C+sequences%5C%3B%5C+thirdly%5C+intramolecular%5C+recombination%5C+in%5C+cpDNA%5C+of%5C+cycads%5C%3B%5C+eventually%5C+the%5C+neotectonic%5C+movement%5C+in%5C+the%5C+distribution%5C+range%5C+of%5C+this%5C+species."},{"jsname":"During a field trip at a brule in Shangri-La, a mixed population of Ligularia Cass. was found, which including L. subspicata (Bur. et Franch.) Hand.-Mazz., L. nelumbifolia (Bur. et Franch.) Hand.-Mazz., L. tongolensis (Franch.) Hand.-Mazz., L. cymbulifera (W.W.Smith) Hand.-Mazz., L. lingiana S.W.Liu, and also some individuals morphologically intermediate between L. subspicata and L. nelumbifolia. Hence, these intermediate individuals were preliminarily assumed as natural hybrids of the two Ligularia. According to their morphology, they’re assumed to form hybrids A and B. Through careful comparison of specimens in herbarium and those we collected, the inflorescence of putative hybrid A is close to L. nelumbifolia, but the shape of laminae are intergradation of L. subspicata and L. nelumbifolia; overall morphology of putative hybrids B is similar to L. nelumbifolia, but inflorescence color is as same as L. subspicata. Compared to L. nelumbifolia (39%) and L. subspicata (36.8%), the germination rate of putative hybrid B (45.7%) slightly higher than the two; but that of hybrid A is extraordinarily low (0.3%). One possible interpretation of the low rate is hybridization. 60 individuals were collected, including putative parents, other 4 species of Ligularia nearby, putative hybrid A and B. They were all direct sequenced of four cpDNA fragments, and direct sequenced or cloning sequenced of nrDNA ITS4-5. The results support that L. nelumbifolia and L. subspicata are parents of putative hybrid A, and the majority female parent is L. subspicata, L. vellerea may also be involved in the hybridization in some degree; the nuclear sequences of putative hybrid B have no superposition, and its chloroplast DNA sequences are identical with L. nelumbifolia, so putative hybrid B could not be hybrid; and there are backcross individuals exist among the putative parent L. subspicata. NewHybrids analysis of ISSR markers indicated that, the individuals of putative hybrid A are almost L. nelumbifolia and L. subspicata F1 hybrid generation (10/11), only 1/11 possibly backcross or other forms; all individuals of hybrid B are L. nelumbifolia; except one individual of L. subspicata as backcrossed, the other parent individuals are 100% reliable. This study focused on molecular evidence, complemented by ecological, reproductive and other characteristics, we demonstrated that the morphologically intermediate individuals’ origin, and the probability of belonging to each parental or hybrid class. And concluded that L. nelumbifolia and L. subspicata are the parents of putative hybrid A, L. vellerea may also be involved in the hybridization in some degree, hybrids mainly are the first generation, a few individuals may be involved in backcross, and most probably backcross with L. subspicata according to the anthesis, while the assumption of hybrid B is not supported.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ADuring%5C+a%5C+field%5C+trip%5C+at%5C+a%5C+brule%5C+in%5C+Shangri%5C-La%2C%5C+a%5C+mixed%5C+population%5C+of%5C+Ligularia%5C+Cass.%5C+was%5C+found%2C%5C+which%5C+including%5C+L.%5C+subspicata%5C+%5C%28Bur.%5C+et%5C+Franch.%5C%29%5C+Hand.%5C-Mazz.%2C%5C+L.%5C+nelumbifolia%5C+%5C%28Bur.%5C+et%5C+Franch.%5C%29%5C+Hand.%5C-Mazz.%2C%5C+L.%5C+tongolensis%5C+%5C%28Franch.%5C%29%5C+Hand.%5C-Mazz.%2C%5C+L.%5C+cymbulifera%5C+%5C%28W.W.Smith%5C%29%5C+Hand.%5C-Mazz.%2C%5C+L.%5C+lingiana%5C+S.W.Liu%2C%5C+and%5C+also%5C+some%5C+individuals%5C+morphologically%5C+intermediate%5C+between%5C+L.%5C+subspicata%5C+and%5C+L.%5C+nelumbifolia.%5C+Hence%2C%5C+these%5C+intermediate%5C+individuals%5C+were%5C+preliminarily%5C+assumed%5C+as%5C+natural%5C+hybrids%5C+of%5C+the%5C+two%5C+Ligularia.%5C+According%5C+to%5C+their%5C+morphology%2C%5C+they%E2%80%99re%5C+assumed%5C+to%5C+form%5C+hybrids%5C+A%5C+and%5C+B.%5C+Through%5C+careful%5C+comparison%5C+of%5C+specimens%5C+in%5C+herbarium%5C+and%5C+those%5C+we%5C+collected%2C%5C+the%5C+inflorescence%5C+of%5C+putative%5C+hybrid%5C+A%5C+is%5C+close%5C+to%5C+L.%5C+nelumbifolia%2C%5C+but%5C+the%5C+shape%5C+of%5C+laminae%5C+are%5C+intergradation%C2%A0of%5C+L.%5C+subspicata%5C+and%5C+L.%5C+nelumbifolia%5C%3B%5C+overall%5C+morphology%5C+of%5C+putative%5C+hybrids%5C+B%5C+is%5C+similar%5C+to%5C+L.%5C+nelumbifolia%2C%5C+but%5C+inflorescence%5C+color%5C+is%5C+as%5C+same%5C+as%5C+L.%5C+subspicata.%5C+Compared%5C+to%5C+L.%5C+nelumbifolia%5C+%5C%2839%25%5C%29%5C+and%5C+L.%5C+subspicata%5C+%5C%2836.8%25%5C%29%2C%5C+the%5C+germination%5C+rate%5C+of%5C+putative%5C+hybrid%5C+B%5C+%5C%2845.7%25%5C%29%5C+slightly%5C+higher%5C+than%5C+the%5C+two%5C%3B%5C+but%5C+that%5C+of%5C+hybrid%5C+A%5C+is%5C+extraordinarily%5C+low%5C+%5C%280.3%25%5C%29.%5C+One%5C+possible%5C+interpretation%5C+of%5C+the%5C+low%5C+rate%5C+is%5C+hybridization.%5C+60%5C+individuals%5C+were%5C+collected%2C%5C+including%5C+putative%5C+parents%2C%5C+other%5C+4%5C+species%5C+of%5C+Ligularia%5C+nearby%2C%5C+putative%5C+hybrid%5C+A%5C+and%5C+B.%5C+They%5C+were%5C+all%5C+direct%5C+sequenced%5C+of%5C+four%5C+cpDNA%5C+fragments%2C%5C+and%5C+direct%5C+sequenced%5C+or%5C+cloning%5C+sequenced%5C+of%5C+nrDNA%5C+ITS4%5C-5.%5C+The%5C+results%5C+support%5C+that%5C+L.%5C+nelumbifolia%5C+and%5C+L.%5C+subspicata%5C+are%5C+parents%5C+of%5C+putative%5C+hybrid%5C+A%2C%5C+and%5C+the%5C+majority%5C+female%5C+parent%5C+is%5C+L.%5C+subspicata%2C%5C+L.%5C+vellerea%5C+may%5C+also%5C+be%5C+involved%5C+in%5C+the%5C+hybridization%5C+in%5C+some%5C+degree%5C%3B%5C+the%5C+nuclear%5C+sequences%5C+of%5C+putative%5C+hybrid%5C+B%5C+have%5C+no%5C+superposition%2C%5C+and%5C+its%5C+chloroplast%5C+DNA%5C+sequences%5C+are%5C+identical%5C+with%5C+L.%5C+nelumbifolia%2C%5C+so%5C+putative%5C+hybrid%5C+B%5C+could%5C+not%5C+be%5C+hybrid%5C%3B%5C+and%5C+there%5C+are%5C+backcross%5C+individuals%5C+exist%5C+among%5C+the%5C+putative%5C+parent%5C+L.%5C+subspicata.%5C+NewHybrids%5C+analysis%5C+of%5C+ISSR%5C+markers%5C+indicated%5C+that%2C%5C+the%5C+individuals%5C+of%5C+putative%5C+hybrid%5C+A%5C+are%5C+almost%5C+L.%5C+nelumbifolia%5C+and%5C+L.%5C+subspicata%5C+F1%5C+hybrid%5C+generation%5C+%5C%2810%5C%2F11%5C%29%2C%5C+only%5C+1%5C%2F11%5C+possibly%5C+backcross%5C+or%5C+other%5C+forms%5C%3B%5C+all%5C+individuals%5C+of%5C+hybrid%5C+B%5C+are%5C+L.%5C+nelumbifolia%5C%3B%5C+except%5C+one%5C+individual%5C+of%5C+L.%5C+subspicata%5C+as%5C+backcrossed%2C%5C+the%5C+other%5C+parent%5C+individuals%5C+are%5C+100%25%5C+reliable.%5C+This%5C+study%5C+focused%5C+on%5C+molecular%5C+evidence%2C%5C+complemented%5C+by%5C+ecological%2C%5C+reproductive%5C+and%5C+other%5C+characteristics%2C%5C+we%5C+demonstrated%5C+that%5C+the%5C+morphologically%5C+intermediate%5C+individuals%E2%80%99%5C+origin%2C%5C+and%5C+the%5C+probability%5C+of%5C+belonging%5C+to%5C+each%5C+parental%5C+or%5C+hybrid%5C+class.%5C+And%5C+concluded%5C+that%5C+L.%5C+nelumbifolia%5C+and%5C+L.%5C+subspicata%5C+are%5C+the%5C+parents%5C+of%5C+putative%5C+hybrid%5C+A%2C%5C+L.%5C+vellerea%5C+may%5C+also%5C+be%5C+involved%5C+in%5C+the%5C+hybridization%5C+in%5C+some%5C+degree%2C%5C+hybrids%5C+mainly%5C+are%5C+the%5C+first%5C+generation%2C%5C+a%5C+few%5C+individuals%5C+may%5C+be%5C+involved%5C+in%5C+backcross%2C%5C+and%5C+most%5C+probably%5C+backcross%5C+with%5C+L.%5C+subspicata%5C+according%5C+to%5C+the%5C+anthesis%2C%5C+while%5C+the%5C+assumption%5C+of%5C+hybrid%5C+B%5C+is%5C+not%5C+supported."},{"jsname":"Following the rapid uplift of the Himalaya, the reorganization of the major river drainages was primarily caused by river capture events，e.g. those of the Jinshajiang River (comprising the Upper, Middle and Lower Jinshajiang) and its tributaries (Yalongjiang, Daduhe, Jialingjiang), the Nujiang, the Lancangjiang, and the Honghe. We selected Terminalia franchetii var. franchetii and T. franchetii var. intricata in the Sino-Himalayan region to study the relationship with Honghe diversion events. The distribution of this species is predicted to have retained genetic signatures of past hydrological landscape structures. The major result as flowing:1. Chloroplast phylogeography of T. franchetii based on haplotype analysis，Based on a range-wide sampling comprising 28 populations and 258 individuals, and using chloroplast DNA sequences (trnL-trnF, petL-psbE), we detected 12 haplotypes. Terminalia franchetii was found to harbour high haplotype diversity (hT = 0.784) but low average within-population diversity (hS = 0.124). The analysis of genetic structure using SAMOVA showed that the number of population groups equaled five, and all the haplotypes can be divided into five groups. Group B and C identified exhibited a disjunctive distribution of dominant haplotypes between northern and southern valleys, corresponding to the geography of past rather than modern drainage systems.Mismatch distribution (multimodal curve) and neutral tests provided no evidence of recent demographic population growth. We suggest that the modern disjunctive distribution of T. franchetii, and associated patterns of cpDNA haplotype variation, result from vicariance caused by several historical river separation and capture events. By assuming a common mutation rate of the cpDNA-IGS regions, our inferred timings of these events (0.82-4.39 Mya) broadly agrees with both previous geological and molecular estimated time of drainage rearrangements in this region. So we conclude that there were several historical vicariance events play a major role for the distribution of T. franchetii in this region.2. Genetic diversity and structure of T. franchetii var. franchetii based on AFLP analysis，We determined the genotype of 251 individuals of T. franchetii var. franchetii from 21 populations using amplified fragment length polymorphism (AFLP), for our aim is only investigated the relationship between the modern distribution of T. franchetii and geological changes in drainage patterns. The overall estimate of genetic structure (Gst) was 0.249, indicating that clear genetic differentiation existed among the populations. Estimates of gene flow (Nm = 0.754) between populations based on the Gst value revealed that the number of migrants per generation is not frequently.Using Neighbor-Joining tree, Principal Coordinates Analysis, STRUCTURE and network methods, Analyses of AFLP markers identified two main population groups (I and II) and four subgroups (A – D) of T. franchetii. Genetic diversity was lower in Group I than in Group II. The results show that Groups I and II probably once occupied continuous areas respectively along ancient drainage systems and there were several historical separation and capture events that can account for the distribution of T. franchetii in this region. After all，these are good examples of the way in which historical events can change a species’ distribution from continuous to fragmented (Jinshajiang/ Yalongjiang and Honghe), and a disjunct distribution to a continuous one (Upper/Lower Jinshajiang and Yalongjiang). The results provide new insights into the phylogeographic pattern of plants in southwest China.3. Relationships between T. franchetii var. franchetii and T. franchetii var. intricata ，While T. franchetii var. Franchetii and var. intricata slightly differ in overall size and leaf hairiness, these taxa did not exhibit reciprocal monophyly. As results show, the genetic difference between the two varieties is much smaller than that within var. franchetii (Salween population vs. other populationsof this variety). It is also revealed in a phylogenetic analysis of ITS region of Combretoideae. The habitats of var. franchetii and var. intricata have obviously difference. Thus, the differences between the two varieties in overall size and leaf hairiness might reflect different phenotypic responses to environmental changes and the divergent environmental niche spaces they occupy. Based on the reasoning above, we agree with Flora of China that “T. intricata” represents a variety of T. franchetii rather than a separate species.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3AFollowing%5C+the%5C+rapid%5C+uplift%5C+of%5C+the%5C+Himalaya%2C%5C+the%5C+reorganization%5C+of%5C+the%5C+major%5C+river%5C+drainages%5C+was%5C+primarily%5C+caused%5C+by%5C+river%5C+capture%5C+events%EF%BC%8Ce.g.%5C+those%5C+of%5C+the%5C+Jinshajiang%5C+River%5C+%5C%28comprising%5C+the%5C+Upper%2C%5C+Middle%5C+and%5C+Lower%5C+Jinshajiang%5C%29%5C+and%5C+its%5C+tributaries%5C+%5C%28Yalongjiang%2C%5C+Daduhe%2C%5C+Jialingjiang%5C%29%2C%5C+the%5C+Nujiang%2C%5C+the%5C+Lancangjiang%2C%5C+and%5C+the%5C+Honghe.%5C+We%5C+selected%5C+Terminalia%5C+franchetii%5C+var.%5C+franchetii%5C+and%5C+T.%5C+franchetii%5C+var.%5C+intricata%5C+in%5C+the%5C+Sino%5C-Himalayan%5C+region%5C+to%5C+study%5C+the%5C+relationship%5C+with%5C+Honghe%5C+diversion%5C+events.%5C+The%5C+distribution%5C+of%5C+this%5C+species%5C+is%5C+predicted%5C+to%5C+have%5C+retained%5C+genetic%5C+signatures%5C+of%5C+past%5C+hydrological%5C+landscape%5C+structures.%5C+The%5C+major%5C+result%5C+as%5C+flowing%5C%3A1.%5C+Chloroplast%5C+phylogeography%5C+of%5C+T.%5C+franchetii%5C+based%5C+on%5C+haplotype%5C+analysis%EF%BC%8CBased%5C+on%5C+a%5C+range%5C-wide%5C+sampling%5C+comprising%5C+28%5C+populations%5C+and%5C+258%5C+individuals%2C%5C+and%5C+using%5C+chloroplast%5C+DNA%5C+sequences%5C+%5C%28trnL%5C-trnF%2C%5C+petL%5C-psbE%5C%29%2C%5C+we%5C+detected%5C+12%5C+haplotypes.%5C+Terminalia%5C+franchetii%5C+was%5C+found%5C+to%5C+harbour%5C+high%5C+haplotype%5C+diversity%5C+%5C%28hT%5C+%3D%5C+0.784%5C%29%5C+but%5C+low%5C+average%5C+within%5C-population%5C+diversity%5C+%5C%28hS%5C+%3D%5C+0.124%5C%29.%5C+The%5C+analysis%5C+of%5C+genetic%5C+structure%5C+using%5C+SAMOVA%5C+showed%5C+that%5C+the%5C+number%5C+of%5C+population%5C+groups%5C+equaled%5C+five%2C%5C+and%5C+all%5C+the%5C+haplotypes%5C+can%5C+be%5C+divided%5C+into%5C+five%5C+groups.%5C+Group%5C+B%5C+and%5C+C%5C+identified%5C+exhibited%5C+a%5C+disjunctive%5C+distribution%5C+of%5C+dominant%5C+haplotypes%5C+between%5C+northern%5C+and%5C+southern%5C+valleys%2C%5C+corresponding%5C+to%5C+the%5C+geography%5C+of%5C+past%5C+rather%5C+than%5C+modern%5C+drainage%5C+systems.Mismatch%5C+distribution%5C+%5C%28multimodal%5C+curve%5C%29%5C+and%5C+neutral%5C+tests%5C+provided%5C+no%5C+evidence%5C+of%5C+recent%5C+demographic%5C+population%5C+growth.%5C+We%5C+suggest%5C+that%5C+the%5C+modern%5C+disjunctive%5C+distribution%5C+of%5C+T.%5C+franchetii%2C%5C+and%5C+associated%5C+patterns%5C+of%5C+cpDNA%5C+haplotype%5C+variation%2C%5C+result%5C+from%5C+vicariance%5C+caused%5C+by%5C+several%5C+historical%5C+river%5C+separation%5C+and%5C+capture%5C+events.%5C+By%5C+assuming%5C+a%5C+common%5C+mutation%5C+rate%5C+of%5C+the%5C+cpDNA%5C-IGS%5C+regions%2C%5C+our%5C+inferred%5C+timings%5C+of%5C+these%5C+events%5C+%5C%280.82%5C-4.39%5C+Mya%5C%29%5C+broadly%5C+agrees%5C+with%5C+both%5C+previous%5C+geological%5C+and%5C+molecular%5C+estimated%5C+time%5C+of%5C+drainage%5C+rearrangements%5C+in%5C+this%5C+region.%5C+So%5C+we%5C+conclude%5C+that%5C+there%5C+were%5C+several%5C+historical%5C+vicariance%5C+events%5C+play%5C+a%5C+major%5C+role%5C+for%5C+the%5C+distribution%5C+of%5C+T.%5C+franchetii%5C+in%5C+this%5C+region.2.%5C+Genetic%5C+diversity%5C+and%5C+structure%5C+of%5C+T.%5C+franchetii%5C+var.%5C+franchetii%5C+based%5C+on%5C+AFLP%5C+analysis%EF%BC%8CWe%5C+determined%5C+the%5C+genotype%5C+of%5C+251%5C+individuals%5C+of%5C+T.%5C+franchetii%5C+var.%5C+franchetii%5C+from%5C+21%5C+populations%5C+using%5C+amplified%5C+fragment%5C+length%5C+polymorphism%5C+%5C%28AFLP%5C%29%2C%5C+for%5C+our%5C+aim%5C+is%5C+only%5C+investigated%5C+the%5C+relationship%5C+between%5C+the%5C+modern%5C+distribution%5C+of%5C+T.%5C+franchetii%5C+and%5C+geological%5C+changes%5C+in%5C+drainage%5C+patterns.%5C+The%5C+overall%5C+estimate%5C+of%5C+genetic%5C+structure%5C+%5C%28Gst%5C%29%5C+was%5C+0.249%2C%5C+indicating%5C+that%5C+clear%5C+genetic%5C+differentiation%5C+existed%5C+among%5C+the%5C+populations.%5C+Estimates%5C+of%5C+gene%5C+flow%5C+%5C%28Nm%5C+%3D%5C+0.754%5C%29%5C+between%5C+populations%5C+based%5C+on%5C+the%5C+Gst%5C+value%5C+revealed%5C+that%5C+the%5C+number%5C+of%5C+migrants%5C+per%5C+generation%5C+is%5C+not%5C+frequently.Using%5C+Neighbor%5C-Joining%5C+tree%2C%5C+Principal%5C+Coordinates%5C+Analysis%2C%5C+STRUCTURE%5C+and%5C+network%5C+methods%2C%5C+Analyses%5C+of%5C+AFLP%5C+markers%5C+identified%5C+two%5C+main%5C+population%5C+groups%5C+%5C%28I%5C+and%5C+II%5C%29%5C+and%5C+four%5C+subgroups%5C+%5C%28A%5C+%E2%80%93%5C+D%5C%29%5C+of%5C+T.%5C+franchetii.%5C+Genetic%5C+diversity%5C+was%5C+lower%5C+in%5C+Group%5C+I%5C+than%5C+in%5C+Group%5C+II.%5C+The%5C+results%5C+show%5C+that%5C+Groups%5C+I%5C+and%5C+II%5C+probably%5C+once%5C+occupied%5C+continuous%5C+areas%5C+respectively%5C+along%5C+ancient%5C+drainage%5C+systems%5C+and%5C+there%5C+were%5C+several%5C+historical%5C+separation%5C+and%5C+capture%5C+events%5C+that%5C+can%5C+account%5C+for%5C+the%5C+distribution%5C+of%5C+T.%5C+franchetii%5C+in%5C+this%5C+region.%5C+After%5C+all%EF%BC%8Cthese%5C+are%5C+good%5C+examples%5C+of%5C+the%5C+way%5C+in%5C+which%5C+historical%5C+events%5C+can%5C+change%5C+a%5C+species%E2%80%99%5C+distribution%5C+from%5C+continuous%5C+to%5C+fragmented%5C+%5C%28Jinshajiang%5C%2F%5C+Yalongjiang%5C+and%5C+Honghe%5C%29%2C%5C+and%5C+a%5C+disjunct%5C+distribution%5C+to%5C+a%5C+continuous%5C+one%5C+%5C%28Upper%5C%2FLower%5C+Jinshajiang%5C+and%5C+Yalongjiang%5C%29.%5C+The%5C+results%5C+provide%5C+new%5C+insights%5C+into%5C+the%5C+phylogeographic%5C+pattern%5C+of%5C+plants%5C+in%5C+southwest%5C+China.3.%5C+Relationships%5C+between%5C+T.%5C+franchetii%5C+var.%5C+franchetii%5C+and%5C+T.%5C+franchetii%5C+var.%5C+intricata%5C+%EF%BC%8CWhile%5C+T.%5C+franchetii%5C+var.%5C+Franchetii%5C+and%5C+var.%5C+intricata%5C+slightly%5C+differ%5C+in%5C+overall%5C+size%5C+and%5C+leaf%5C+hairiness%2C%5C+these%5C+taxa%5C+did%5C+not%5C+exhibit%5C+reciprocal%5C+monophyly.%5C+As%5C+results%5C+show%2C%5C+the%5C+genetic%5C+difference%5C+between%5C+the%5C+two%5C+varieties%5C+is%5C+much%5C+smaller%5C+than%5C+that%5C+within%5C+var.%5C+franchetii%5C+%5C%28Salween%5C+population%5C+vs.%5C+other%5C+populationsof%5C+this%5C+variety%5C%29.%5C+It%5C+is%5C+also%5C+revealed%5C+in%5C+a%5C+phylogenetic%5C+analysis%5C+of%5C+ITS%5C+region%5C+of%5C+Combretoideae.%5C+The%5C+habitats%5C+of%5C+var.%5C+franchetii%5C+and%5C+var.%5C+intricata%5C+have%5C+obviously%5C+difference.%5C+Thus%2C%5C+the%5C+differences%5C+between%5C+the%5C+two%5C+varieties%5C+in%5C+overall%5C+size%5C+and%5C+leaf%5C+hairiness%5C+might%5C+reflect%5C+different%5C+phenotypic%5C+responses%5C+to%5C+environmental%5C+changes%5C+and%5C+the%5C+divergent%5C+environmental%5C+niche%5C+spaces%5C+they%5C+occupy.%5C+Based%5C+on%5C+the%5C+reasoning%5C+above%2C%5C+we%5C+agree%5C+with%5C+Flora%5C+of%5C+China%5C+that%5C+%E2%80%9CT.%5C+intricata%E2%80%9D%5C+represents%5C+a%5C+variety%5C+of%5C+T.%5C+franchetii%5C+rather%5C+than%5C+a%5C+separate%5C+species."},{"jsname":"National Natural Science Foundation of China[31470336]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANational%5C+Natural%5C+Science%5C+Foundation%5C+of%5C+China%5C%5B31470336%5C%5D"},{"jsname":"National Natural Science Foundation of China[31600178]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANational%5C+Natural%5C+Science%5C+Foundation%5C+of%5C+China%5C%5B31600178%5C%5D"},{"jsname":"National Research Council of Thailand (Mae Fah Luang University)[592010200112]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANational%5C+Research%5C+Council%5C+of%5C+Thailand%5C+%5C%28Mae%5C+Fah%5C+Luang%5C+University%5C%29%5C%5B592010200112%5C%5D"},{"jsname":"National Research Council of Thailand (Mae Fah Luang University)[60201000201]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANational%5C+Research%5C+Council%5C+of%5C+Thailand%5C+%5C%28Mae%5C+Fah%5C+Luang%5C+University%5C%29%5C%5B60201000201%5C%5D"},{"jsname":"National Science Foundation of China (NSFC)[31750110478]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANational%5C+Science%5C+Foundation%5C+of%5C+China%5C+%5C%28NSFC%5C%29%5C%5B31750110478%5C%5D"},{"jsname":"National Science Foundation of China[31470336]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANational%5C+Science%5C+Foundation%5C+of%5C+China%5C%5B31470336%5C%5D"},{"jsname":"National Science Foundation of China[31600178]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANational%5C+Science%5C+Foundation%5C+of%5C+China%5C%5B31600178%5C%5D"},{"jsname":"Natural hybridization has many evolutionary consequences, such as the origin of new ecotypes or species and the maintenance of reproductive barriers. However, few studies have involved in and quantified the potential threat to rare species by natural hybridization. In this study, we focused on the hybridization between a narrow endemic species R. cyanocarpum Franch. ex W.W. Sm and the widespread species R. delavayi Franch.. We revealed this process of natural hybridization, composition and possible significance of the detected single hybrid zone and comparative analysis of fitness among parental species and the hybrids. These significant results were summarized as follows: 1. Field observation and comparative analysis of morphological characters, We investigated 6 sites where R. cyanocarpum distributed, and found the single putative hybrid zone only in one site. 22 morphological characters were selected and measured, according to which the putative parental species were determined. Among the examined morphological characters, intermediate characters accounted for 45%, whereas the transgressive characters accounted for 14%. These results showed that intermediate characters were predominant. In addition, the ecological adaptations of these transgressive characters remain unknown. 2. Reproductive biology and reproductive evidence for natural hybridization, Three main results were achieved via the study of pollination biology of R. cyanocarpum: (1) from the results of floral color experiments, we found that the pink flowers have preponderant adaptation over the white ones. Because either proportions of individuals with pink flowers within and between populations, or visitation rate of pollinators were all significant higher than white types; (2) the effective pollinators of R. cyanocarpum were solely the bumblebees (Bombus festivces and B. richardsi), and the pollination is primarily due to geitonogamy that is mediated by bumblebees; (3) most of fruits were either composed of 5 or 6 carpels. Moreover, the proportions of carpel number per fruit were significantly related to the altitudes ((r=0.807, p<0.01) and the positions of inflorescence (r=0.62, p<0.01). Meanwhile, seed weight, seed number and seed germination rate were significant difference to the fruits with different carpel number; For R. delavayi, the experiment showed that the associated function of nectary and spots promote reproductive success in R. delavayi, because of significantly higher fruit production was examined in half petal deprived with degenerative nectarines than in half petal deprived with normal ones. Reciprocal hand pollination treatments showed that either species, as pollen donor or pollen receiver, could produce fruits indicating weak reproductive barriers between species. It was noted that fruit set varied among treatments. The same pollinators (bumblebees) were shared in both parental species. Therefore, flowering period overlapping, weak reproductive barriers and sharing the same pollinators, all contributed to reproductive evidence for the possible occurrence of natural hybridization between R. cyanocarpum and R. delavayi. 3. Molecular evidence for natural hybridization, On the basis of two nuclear DNA (ITS and Waxy) and three chloroplast DNA (trnC-F, trnH-psbA and trnL-rpl32), hybrids and parental species were clearly identified and individuals with intermediate morphologies are indeed of hybrid origin from natural hybridization between R. cyanocarpum and R. delavayi. Hybridization occurred in both directions, but was asymmetrical, with R. delavayi as the major maternal parent (90%) whereas only one hybrid had identical chloroplast to R. cyanocarpum (10%). 4. The study of hybrid zone, Two molecular methods were employed to successfully disclosed characters of the single hybrid zone: (1) this hybrid zone was composed of parental species, F1s, F2s and backcross derivatives; (2) F2s outnumbered either F1s or backcross derivatives; (3) the direction of gene flow was from R. cyanocarpum to R. delavayi. Based on the one directional gene flow and fewer hybrids formation in the single hybrid zone, no threat to R. cyanocarpum posed by natural hybridization was observed. However, such a threat is likely to arise if more hybrids are produced via serious habitat disturbance. 5. Comparative analysis of fitness among parental species and hybrids, We made a preliminary result that the fitness of hybrids’ offspring is not always lower than their parental offsprings, after comparative analysis of some detected fitness index in experimental condition, such as the lengths of radicle and hypocotyls, and the seedling height. Therefore, it is reasonable to presume that these hybrids can have similar or higher fitness than parental species only if natural habitat is changed substantially in a short period.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ANatural%5C+hybridization%5C+has%5C+many%5C+evolutionary%5C+consequences%2C%5C+such%5C+as%5C+the%5C+origin%5C+of%5C+new%5C+ecotypes%5C+or%5C+species%5C+and%5C+the%5C+maintenance%5C+of%5C+reproductive%5C+barriers.%5C+However%2C%5C+few%5C+studies%5C+have%5C+involved%5C+in%5C+and%5C+quanti%EF%AC%81ed%5C+the%5C+potential%5C+threat%5C+to%5C+rare%5C+species%5C+by%5C+natural%5C+hybridization.%5C+In%5C+this%5C+study%2C%5C+we%5C+focused%5C+on%5C+the%5C+hybridization%5C+between%5C+a%5C+narrow%5C+endemic%5C+species%5C+R.%5C+cyanocarpum%5C+Franch.%5C+ex%5C+W.W.%5C+Sm%5C+and%5C+the%5C+widespread%5C+species%5C+R.%5C+delavayi%5C+Franch..%5C+We%5C+revealed%5C+this%5C+process%5C+of%5C+natural%5C+hybridization%2C%5C+composition%5C+and%5C+possible%5C+significance%5C+of%5C+the%5C+detected%5C+single%5C+hybrid%5C+zone%5C+and%5C+comparative%5C+analysis%5C+of%5C+fitness%5C+among%5C+parental%5C+species%5C+and%5C+the%5C+hybrids.%5C+These%5C+significant%5C+results%5C+were%5C+summarized%5C+as%5C+follows%5C%3A%5C+1.%5C+Field%5C+observation%5C+and%5C+comparative%5C+analysis%5C+of%5C+morphological%5C+characters%2C%5C+We%5C+investigated%5C+6%5C+sites%5C+where%5C+R.%5C+cyanocarpum%5C+distributed%2C%5C+and%5C+found%5C+the%5C+single%5C+putative%5C+hybrid%5C+zone%5C+only%5C+in%5C+one%5C+site.%5C+22%5C+morphological%5C+characters%5C+were%5C+selected%5C+and%5C+measured%2C%5C+according%5C+to%5C+which%5C+the%5C+putative%5C+parental%5C+species%5C+were%5C+determined.%5C+Among%5C+the%5C+examined%5C+morphological%5C+characters%2C%5C+intermediate%5C+characters%5C+accounted%5C+for%5C+45%25%2C%5C+whereas%5C+the%5C+transgressive%5C+characters%5C+accounted%5C+for%5C+14%25.%5C+These%5C+results%5C+showed%5C+that%5C+intermediate%5C+characters%5C+were%5C+predominant.%5C+In%5C+addition%2C%5C+the%5C+ecological%5C+adaptations%5C+of%5C+these%5C+transgressive%5C+characters%5C+remain%5C+unknown.%5C+2.%5C+Reproductive%5C+biology%5C+and%5C+reproductive%5C+evidence%5C+for%5C+natural%5C+hybridization%2C%5C+Three%5C+main%5C+results%5C+were%5C+achieved%5C+via%5C+the%5C+study%5C+of%5C+pollination%5C+biology%5C+of%5C+R.%5C+cyanocarpum%5C%3A%5C+%5C%281%5C%29%5C+from%5C+the%5C+results%5C+of%5C+floral%5C+color%5C+experiments%2C%5C+we%5C+found%5C+that%5C+the%5C+pink%5C+flowers%5C+have%5C+preponderant%5C+adaptation%5C+over%5C+the%5C+white%5C+ones.%5C+Because%5C+either%5C+proportions%5C+of%5C+individuals%5C+with%5C+pink%5C+flowers%5C+within%5C+and%5C+between%5C+populations%2C%5C+or%5C+visitation%5C+rate%5C+of%5C+pollinators%5C+were%5C+all%5C+significant%5C+higher%5C+than%5C+white%5C+types%5C%3B%5C+%5C%282%5C%29%5C+the%5C+effective%5C+pollinators%5C+of%5C+R.%5C+cyanocarpum%5C+were%5C+solely%5C+the%5C+bumblebees%5C+%5C%28Bombus%5C+festivces%5C+and%5C+B.%5C+richardsi%5C%29%2C%5C+and%5C+the%5C+pollination%5C+is%5C+primarily%5C+due%5C+to%5C+geitonogamy%5C+that%5C+is%5C+mediated%5C+by%5C+bumblebees%5C%3B%5C+%5C%283%5C%29%5C+most%5C+of%5C+fruits%5C+were%5C+either%5C+composed%5C+of%5C+5%5C+or%5C+6%5C+carpels.%5C+Moreover%2C%5C+the%5C+proportions%5C+of%5C+carpel%5C+number%5C+per%5C+fruit%5C+were%5C+significantly%5C+related%5C+to%5C+the%5C+altitudes%5C+%5C%28%5C%28r%3D0.807%2C%5C+p%3C0.01%5C%29%5C+and%5C+the%5C+positions%5C+of%5C+inflorescence%5C+%5C%28r%3D0.62%2C%5C+p%3C0.01%5C%29.%5C+Meanwhile%2C%5C+seed%5C+weight%2C%5C+seed%5C+number%5C+and%5C+seed%5C+germination%5C+rate%5C+were%5C+significant%5C+difference%5C+to%5C+the%5C+fruits%5C+with%5C+different%5C+carpel%5C+number%5C%3B%C2%A0For%5C+R.%5C+delavayi%2C%5C+the%5C+experiment%5C+showed%5C+that%5C+the%5C+associated%5C+function%5C+of%5C+nectary%5C+and%5C+spots%5C+promote%5C+reproductive%5C+success%5C+in%5C+R.%5C+delavayi%2C%5C+because%5C+of%5C+significantly%5C+higher%5C+fruit%5C+production%5C+was%5C+examined%5C+in%5C+half%5C+petal%5C+deprived%5C+with%5C+degenerative%5C+nectarines%5C+than%5C+in%5C+half%5C+petal%5C+deprived%5C+with%5C+normal%5C+ones.%5C+Reciprocal%5C+hand%5C+pollination%5C+treatments%5C+showed%5C+that%5C+either%5C+species%2C%5C+as%5C+pollen%5C+donor%5C+or%5C+pollen%5C+receiver%2C%5C+could%5C+produce%5C+fruits%5C+indicating%5C+weak%5C+reproductive%5C+barriers%5C+between%5C+species.%5C+It%5C+was%5C+noted%5C+that%5C+fruit%5C+set%5C+varied%5C+among%5C+treatments.%5C+The%5C+same%5C+pollinators%5C+%5C%28bumblebees%5C%29%5C+were%5C+shared%5C+in%5C+both%5C+parental%5C+species.%5C+Therefore%2C%5C+flowering%5C+period%5C+overlapping%2C%5C+weak%5C+reproductive%5C+barriers%5C+and%5C+sharing%5C+the%5C+same%5C+pollinators%2C%5C+all%5C+contributed%5C+to%5C+reproductive%5C+evidence%5C+for%5C+the%5C+possible%5C+occurrence%5C+of%5C+natural%5C+hybridization%5C+between%5C+R.%5C+cyanocarpum%5C+and%5C+R.%5C+delavayi.%5C+3.%5C+Molecular%5C+evidence%5C+for%5C+natural%5C+hybridization%2C%5C+On%5C+the%5C+basis%5C+of%5C+two%5C+nuclear%5C+DNA%5C+%5C%28ITS%5C+and%5C+Waxy%5C%29%5C+and%5C+three%5C+chloroplast%5C+DNA%5C+%5C%28trnC%5C-F%2C%5C+trnH%5C-psbA%5C+and%5C+trnL%5C-rpl32%5C%29%2C%5C+hybrids%5C+and%5C+parental%5C+species%5C+were%5C+clearly%5C+identi%EF%AC%81ed%5C+and%5C+individuals%5C+with%5C+intermediate%5C+morphologies%5C+are%5C+indeed%5C+of%5C+hybrid%5C+origin%5C+from%5C+natural%5C+hybridization%5C+between%5C+R.%5C+cyanocarpum%5C+and%5C+R.%5C+delavayi.%5C+Hybridization%5C+occurred%5C+in%5C+both%5C+directions%2C%5C+but%5C+was%5C+asymmetrical%2C%5C+with%5C+R.%5C+delavayi%5C+as%5C+the%5C+major%5C+maternal%5C+parent%5C+%5C%2890%25%5C%29%5C+whereas%5C+only%5C+one%5C+hybrid%5C+had%5C+identical%5C+chloroplast%5C+to%5C+R.%5C+cyanocarpum%5C+%5C%2810%25%5C%29.%5C+4.%5C+The%5C+study%5C+of%5C+hybrid%5C+zone%2C%5C+Two%5C+molecular%5C+methods%5C+were%5C+employed%5C+to%5C+successfully%5C+disclosed%5C+characters%5C+of%5C+the%5C+single%5C+hybrid%5C+zone%5C%3A%5C+%5C%281%5C%29%5C+this%5C+hybrid%5C+zone%5C+was%5C+composed%5C+of%5C+parental%5C+species%2C%5C+F1s%2C%5C+F2s%5C+and%5C+backcross%5C+derivatives%5C%3B%5C+%5C%282%5C%29%5C+F2s%5C+outnumbered%5C+either%5C+F1s%5C+or%5C+backcross%5C+derivatives%5C%3B%5C+%5C%283%5C%29%5C+the%5C+direction%5C+of%5C+gene%5C+flow%5C+was%5C+from%5C+R.%5C+cyanocarpum%5C+to%5C+R.%5C+delavayi.%5C+Based%5C+on%5C+the%5C+one%5C+directional%5C+gene%5C+flow%5C+and%5C+fewer%5C+hybrids%5C+formation%5C+in%5C+the%5C+single%5C+hybrid%5C+zone%2C%5C+no%5C+threat%5C+to%5C+R.%5C+cyanocarpum%5C+posed%5C+by%5C+natural%5C+hybridization%5C+was%5C+observed.%5C+However%2C%5C+such%5C+a%5C+threat%5C+is%5C+likely%5C+to%5C+arise%5C+if%5C+more%5C+hybrids%5C+are%5C+produced%5C+via%5C+serious%5C+habitat%5C+disturbance.%5C+5.%5C+Comparative%5C+analysis%5C+of%5C+fitness%5C+among%5C+parental%5C+species%5C+and%5C+hybrids%2C%5C+We%5C+made%5C+a%5C+preliminary%5C+result%5C+that%5C+the%5C+fitness%5C+of%5C+hybrids%E2%80%99%5C+offspring%5C+is%5C+not%5C+always%5C+lower%5C+than%5C+their%5C+parental%5C+offsprings%2C%5C+after%5C+comparative%5C+analysis%5C+of%5C+some%5C+detected%5C+fitness%5C+index%5C+in%5C+experimental%5C+condition%2C%5C+such%5C+as%5C+the%5C+lengths%5C+of%5C+radicle%5C+and%5C+hypocotyls%2C%5C+and%5C+the%5C+seedling%5C+height.%5C+Therefore%2C%5C+it%5C+is%5C+reasonable%5C+to%5C+presume%5C+that%5C+these%5C+hybrids%5C+can%5C+have%5C+similar%5C+or%5C+higher%5C+fitness%5C+than%5C+parental%5C+species%5C+only%5C+if%5C+natural%5C+habitat%5C+is%5C+changed%5C+substantially%5C+in%5C+a%5C+short%5C+period."},{"jsname":"Polyploidy appears to be the most significant mode of sympatric speciation, it is a prevalent phenomenon in species. In this research to investigate the distribution pattern we analysed 27 populations over 500 individuals’ karyotypes and compared morphological characters between different populations to investigate the morphological polymorphism of different ploidy. Parsimony analysis within 2 non-coding loci from chloroplast genome and rDNA ITS, combined the karyotype and morphological results to disscussed the way and the frequency of tetraploids origin. The major results are shown as follows:1. Karyotypes of different populations in A. mairei，27 populations were studied, 13 diploid and 14 tetraploid populations have been detected. No populations have both ploidy coexist. Three karyotype formulas in diploid: 2n=16m，2n=14m+2sm and 2n=12m+4sm; Four karyotype formulas in tetraploid: 2n=30m+2sm，2n=28m+4sm，2n=26m+6sm，2n=28m+2sm+2st. The karyotypes of all populations showed great similarity. Most chromosomes types are “m” and“sm”,only one “st”found in Songming population. The As.K.% ranged from 54.70% to 57.96% .All karyotype found showed original with type 1A or 2A. Based on the evolutionary trend of karyotype is symmetry to asymmetry, A. mairei is very original in karyotype even compared with other species in the genus Allium.2 .The distribution pattern of populations with different ploidy，Both cytotypes occur across a wide range in the distribution area. But the diploid cytotype was rarely found in the east of Yunnan province, and diploid cytotype prefer higher altitude. The tetraploid is extremely common in the east of Yunnan but rarely found in the west, and tetraploid prefer lower altitudes. No correlation found between the distribution patterns and the karyotype asymmetry. Bisides few populations, the karyotype asymmetry in most tetraploid population are similar with diploid, and the smallest karyotype asymmetry found in tetraploid. So based on the karyotype couldn’t found the evolution trend between two poloidy in A. maimei. This result may implied the multiple origins of the tetraploid in A. maimei, some progenitors of tetraploid were distinct, caused no correlation found between two ploidy. Another possibility is the tetraploid spread very quickly after origins, so the change of the karyotype is not obvious. 3. Morphological Polymorphism of different ploidy，The analysis of variation and multiple comparisons with a result of all characters significantly different among /in populations.Characters using numerical taxonomic method Q cluster reveals that ploidy level has little correlation with the morphological variation. The morphological variations in A. mairei are more correlate with Climte and environment. Because the diploids in west Yunnan have more morphological variations. No obvious morphological differentiation between diploid and tetraploid，the tetraploids in A. maimei are autopolyploid from the sight of morphology.4. Autopolyploid and multiple origins of tetraploids in A. mairei，The parsimony analyses of ITS sequence based on the sampling strategy of A. mairei populations with different species of Allium. The strict consensus tree show the diploids and tetraploids of A. mairei to be monophyletic (100% bootstrap). No hybridization between A. mairei and relatives. The result indicates independent polyploidization processes in A. mairei, and support tetraploids in A. mairei are autopolyploid. Based on 27 haplotypes derived form two cpDNA fragments (rpl32-trnL and psbD-trhT), the network analyses showed tetraploids in A.mairei have arisen at least three times. Phylogenetic analyses based on ITS variation types showed the reproductive isolation between diploid and teraploid may not exist.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3APolyploidy%5C+appears%5C+to%5C+be%5C+the%5C+most%5C+significant%5C+mode%5C+of%5C+sympatric%5C+speciation%2C%5C+it%5C+is%5C+a%5C+prevalent%5C+phenomenon%5C+in%5C+species.%5C+In%5C+this%5C+research%5C+to%5C+investigate%5C+the%5C+distribution%5C+pattern%5C+we%5C+analysed%5C+27%5C+populations%5C+over%5C+500%5C+individuals%E2%80%99%5C+karyotypes%5C+and%5C+compared%5C+morphological%5C+characters%5C+between%5C+different%5C+populations%5C+to%5C+investigate%5C+the%5C+morphological%5C+polymorphism%5C+of%5C+different%5C+ploidy.%5C+Parsimony%5C+analysis%5C+within%5C+2%5C+non%5C-coding%5C+loci%5C+from%5C+chloroplast%5C+genome%5C+and%5C+rDNA%5C+ITS%2C%5C+combined%5C+the%5C+karyotype%5C+and%5C+morphological%5C+results%5C+to%5C+disscussed%5C+the%5C+way%5C+and%5C+the%5C+frequency%5C+of%5C+tetraploids%5C+origin.%5C+The%5C+major%5C+results%5C+are%5C+shown%5C+as%5C+follows%5C%3A1.%5C+Karyotypes%5C+of%5C+different%5C+populations%5C+in%5C+A.%5C+mairei%EF%BC%8C27%5C+populations%5C+were%5C+studied%2C%5C+13%5C+diploid%5C+and%5C+14%5C+tetraploid%5C+populations%5C+have%5C+been%5C+detected.%5C+No%5C+populations%5C+have%5C+both%5C+ploidy%5C+coexist.%5C+Three%5C+karyotype%5C+formulas%5C+in%5C+diploid%5C%3A%5C+2n%3D16m%EF%BC%8C2n%3D14m%5C%2B2sm%5C+and%5C+2n%3D12m%5C%2B4sm%5C%3B%5C+Four%5C+karyotype%5C+formulas%5C+in%5C+tetraploid%5C%3A%5C+2n%3D30m%5C%2B2sm%EF%BC%8C2n%3D28m%5C%2B4sm%EF%BC%8C2n%3D26m%5C%2B6sm%EF%BC%8C2n%3D28m%5C%2B2sm%5C%2B2st.%5C+The%5C+karyotypes%5C+of%5C+all%5C+populations%5C+showed%5C+great%5C+similarity.%5C+Most%5C+chromosomes%5C+types%5C+are%5C+%E2%80%9Cm%E2%80%9D%5C+and%E2%80%9Csm%E2%80%9D%2Conly%5C+one%5C+%E2%80%9Cst%E2%80%9Dfound%5C+in%5C+Songming%5C+population.%5C+The%5C+As.K.%25%5C+ranged%5C+from%5C+54.70%25%5C+to%5C+57.96%25%5C+.All%5C+karyotype%5C+found%5C+showed%5C+original%5C+with%5C+type%5C+1A%5C+or%5C+2A.%5C+Based%5C+on%5C+the%5C+evolutionary%5C+trend%5C+of%5C+karyotype%5C+is%5C+symmetry%5C+to%5C+asymmetry%2C%5C+A.%5C+mairei%5C+is%5C+very%5C+original%5C+in%5C+karyotype%5C+even%5C+compared%5C+with%5C+other%5C+species%5C+in%5C+the%5C+genus%5C+Allium.2%5C+.The%5C+distribution%5C+pattern%5C+of%5C+populations%5C+with%5C+different%5C+ploidy%EF%BC%8CBoth%5C+cytotypes%5C+occur%5C+across%5C+a%5C+wide%5C+range%5C+in%5C+the%5C+distribution%5C+area.%5C+But%5C+the%5C+diploid%5C+cytotype%5C+was%5C+rarely%5C+found%5C+in%5C+the%5C+east%5C+of%5C+Yunnan%5C+province%2C%5C+and%5C+diploid%5C+cytotype%5C+prefer%5C+higher%5C+altitude.%5C+The%5C+tetraploid%5C+is%5C+extremely%5C+common%5C+in%5C+the%5C+east%5C+of%5C+Yunnan%5C+but%5C+rarely%5C+found%5C+in%5C+the%5C+west%2C%5C+and%5C+tetraploid%5C+prefer%5C+lower%5C+altitudes.%5C+No%5C+correlation%5C+found%5C+between%5C+the%5C+distribution%5C+patterns%5C+and%5C+the%5C+karyotype%5C+asymmetry.%5C+Bisides%5C+few%5C+populations%2C%5C+the%5C+karyotype%5C+asymmetry%5C+in%5C+most%5C+tetraploid%5C+population%5C+are%5C+similar%5C+with%5C+diploid%2C%5C+and%5C+the%5C+smallest%5C+karyotype%5C+asymmetry%5C+found%5C+in%5C+tetraploid.%5C+So%5C+based%5C+on%5C+the%5C+karyotype%5C+couldn%E2%80%99t%5C+found%5C+the%5C+evolution%5C+trend%5C+between%5C+two%5C+poloidy%5C+in%5C+A.%5C+maimei.%5C+This%5C+result%5C+may%5C+implied%5C+the%5C+multiple%5C+origins%5C+of%5C+the%5C+tetraploid%5C+in%5C+A.%5C+maimei%2C%5C+some%5C+progenitors%5C+of%5C+tetraploid%5C+were%5C+distinct%2C%5C+caused%5C+no%5C+correlation%5C+found%5C+between%5C+two%5C+ploidy.%5C+Another%5C+possibility%5C+is%5C+the%5C+tetraploid%5C+spread%5C+very%5C+quickly%5C+after%5C+origins%2C%5C+so%5C+the%5C+change%5C+of%5C+the%5C+karyotype%5C+is%5C+not%5C+obvious.%5C+3.%5C+Morphological%5C+Polymorphism%5C+of%5C+different%5C+ploidy%EF%BC%8CThe%5C+analysis%5C+of%5C+variation%5C+and%5C+multiple%5C+comparisons%5C+with%5C+a%5C+result%5C+of%5C+all%5C+characters%5C+significantly%5C+different%5C+among%5C+%5C%2Fin%5C+populations.Characters%5C+using%5C+numerical%5C+taxonomic%5C+method%5C+Q%5C+cluster%5C+reveals%5C+that%5C+ploidy%5C+level%5C+has%5C+little%5C+correlation%5C+with%5C+the%5C+morphological%5C+variation.%5C+The%5C+morphological%5C+variations%5C+in%5C+A.%5C+mairei%5C+are%5C+more%5C+correlate%5C+with%5C+Climte%5C+and%5C+environment.%5C+Because%5C+the%5C+diploids%5C+in%5C+west%5C+Yunnan%5C+have%5C+more%5C+morphological%5C+variations.%5C+No%5C+obvious%5C+morphological%5C+differentiation%5C+between%5C+diploid%5C+and%5C+tetraploid%EF%BC%8Cthe%5C+tetraploids%5C+in%5C+A.%5C+maimei%5C+are%5C+autopolyploid%5C+from%5C+the%5C+sight%5C+of%5C+morphology.4.%5C+Autopolyploid%5C+and%5C+multiple%5C+origins%5C+of%5C+tetraploids%5C+in%5C+A.%5C+mairei%EF%BC%8CThe%5C+parsimony%5C+analyses%5C+of%5C+ITS%5C+sequence%5C+based%5C+on%5C+the%5C+sampling%5C+strategy%5C+of%5C+A.%5C+mairei%5C+populations%5C+with%5C+different%5C+species%5C+of%5C+Allium.%5C+The%5C+strict%5C+consensus%5C+tree%5C+show%5C+the%5C+diploids%5C+and%5C+tetraploids%5C+of%5C+A.%5C+mairei%5C+to%5C+be%5C+monophyletic%5C+%5C%28100%25%5C+bootstrap%5C%29.%5C+No%5C+hybridization%5C+between%5C+A.%5C+mairei%5C+and%5C+relatives.%5C+The%5C+result%5C+indicates%5C+independent%5C+polyploidization%5C+processes%5C+in%5C+A.%5C+mairei%2C%5C+and%5C+support%5C+tetraploids%5C+in%5C+A.%5C+mairei%5C+are%5C+autopolyploid.%5C+Based%5C+on%5C+27%5C+haplotypes%5C+derived%5C+form%5C+two%5C+cpDNA%5C+fragments%5C+%5C%28rpl32%5C-trnL%5C+and%5C+psbD%5C-trhT%5C%29%2C%5C+the%5C+network%5C+analyses%5C+showed%5C+tetraploids%5C+in%5C+A.mairei%5C+have%5C+arisen%5C+at%5C+least%5C+three%5C+times.%5C+Phylogenetic%5C+analyses%5C+based%5C+on%5C+ITS%5C+variation%5C+types%5C+showed%5C+the%5C+reproductive%5C+isolation%5C+between%5C+diploid%5C+and%5C+teraploid%5C+may%5C+not%5C+exist."},{"jsname":"Polyploidy, the presence of three or more genomes in an organism, has occurred extensively in plants, and plays a major role in the evolution and speciation of angiosperm. Despite extensive study of the cytotypes distribution and origin of polyploidy, few studies have been reported in China, especially in southwest region. Allium wallichii Kunth (Alliaceae) is a perennial herb, distributed in southwest China, northen India, Nepal, Sikkim and Bhutan. The multiple ploidy levels and rapid differentiation has made A. wallichii a good candidate for studying polyploidy. The cytotypes distribution and origin of A. wallichii polyploidy has been studied in Yunnan-Guizhou Plateu, a main distribution area of this plant. Root-tip squashes were used to identify the ploidy level and karyotypes of 412 plants from 17 populations sampled from Yunnan-Guizhou Plateau. Based on nuclear ITS DNA sequences in 83 individuals from 17 populations, phylogentic analysis were performed to investigate types of A. wallichii polyloids, and determine if the reproductive isolation has been established between diploids and tetraploids. Based on two chloroplast DNA (cpDNA) fragments (petL-psbE, trnQ-rps16), haplotypes were identified , and the origination of tetraploids were analyzed. The main results and conclusions are as follows: 1. Distribution of cytotypes, Cytotype distribution was analyzed based on 412 newly studied plants from seventeen populations and published literatures. Nine diploid populations, six diploid-tetraploid mixed populations occur in central to northwest Yunnan, while twelve tetraploid populations occur in the Yunnan-Guizhou Plateau. Furthermore, tetraploids has a wider altitude range (1400-3726 m) than diploids (2100-3638 m), which suggests the adaptative ability of tetraploid is much stronger than its diploid pregnancies. Tetraploid populations distributed in northwest Yunnan have much lower karyotype asymmetry with the asymmetry indexes (AI) ranges from 1.83 to 2.87 compared to other populations of other areas (AI, 2.03-3.02). This suggests tetraploid in northwest Yunnan is likely to have an earlier derivation. 2. Autoploidization origin of the tetraploids, Diploids are all 2A type except that Zhongdian D and Baoshan populations are 3A type, and tetraploids are all 2A type but Huize and Hezhang populations are 2B type. It shows high similarity of karyotypes of diploid and tetraploids. In addition, the undistinguishable morphology of A. wallichii with different ploidy levels in northwest Yunnan and the monophyly of A. wallichii in ITS strict consensus tree all suggest autopolyploid origins of tetraploids A. wallichii. 3. Multiple origins of tetraploids, Based on two cpDNA fragments (petL-psbE, trnQ-rps16) in 85 individuals from 17 populations across the Yunnan-Guizhou Plateau, a total of 17 haplotypes were identified, among them, 3 in diploids only, 11 in tetraploids only, and 3 found in both cytotypes. This, plus network analyses, indicated that tetraploids have arisen independently from diploids at least three times. 4. Productive isolation between diploids and teraploids, ITS phylogenetic analyses between diploid and tetraploid A. wallichii shows that diploids and tetraploids are both monophyly, with bootstrap value 100% and 88% respectively, indicating that the reproductive isolation has been established between them. Based on cpDNA haplotypes and ITS variation types analyses, extensive hybridization and gene introgression may have occurred among tetraploids.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3APolyploidy%2C%5C+the%5C+presence%5C+of%5C+three%5C+or%5C+more%5C+genomes%5C+in%5C+an%5C+organism%2C%5C+has%5C+occurred%5C+extensively%5C+in%5C+plants%2C%5C+and%5C+plays%5C+a%5C+major%5C+role%5C+in%5C+the%5C+evolution%5C+and%5C+speciation%5C+of%5C+angiosperm.%5C+Despite%5C+extensive%5C+study%5C+of%5C+the%5C+cytotypes%5C+distribution%5C+and%5C+origin%5C+of%5C+polyploidy%2C%5C+few%5C+studies%5C+have%5C+been%5C+reported%5C+in%5C+China%2C%5C+especially%5C+in%5C+southwest%5C+region.%5C+Allium%5C+wallichii%5C+Kunth%5C+%5C%28Alliaceae%5C%29%5C+is%5C+a%5C+perennial%5C+herb%2C%5C+distributed%5C+in%5C+southwest%5C+China%2C%5C+northen%5C+India%2C%5C+Nepal%2C%5C+Sikkim%5C+and%5C+Bhutan.%5C+The%5C+multiple%5C+ploidy%5C+levels%5C+and%5C+rapid%5C+differentiation%5C+has%5C+made%5C+A.%5C+wallichii%5C+a%5C+good%5C+candidate%5C+for%5C+studying%5C+polyploidy.%5C+The%5C+cytotypes%5C+distribution%5C+and%5C+origin%5C+of%5C+A.%5C+wallichii%5C+polyploidy%5C+has%5C+been%5C+studied%5C+in%5C+Yunnan%5C-Guizhou%5C+Plateu%2C%5C+a%5C+main%5C+distribution%5C+area%5C+of%5C+this%5C+plant.%5C+Root%5C-tip%5C+squashes%5C+were%5C+used%5C+to%5C+identify%5C+the%5C+ploidy%5C+level%5C+and%5C+karyotypes%5C+of%5C+412%5C+plants%5C+from%5C+17%5C+populations%5C+sampled%5C+from%5C+Yunnan%5C-Guizhou%5C+Plateau.%5C+Based%5C+on%5C+nuclear%5C+ITS%5C+DNA%5C+sequences%5C+in%5C+83%5C+individuals%5C+from%5C+17%5C+populations%2C%5C+phylogentic%5C+analysis%5C+were%5C+performed%5C+to%5C+investigate%5C+types%5C+of%5C+A.%5C+wallichii%5C+polyloids%2C%5C+and%5C+determine%5C+if%5C+the%5C+reproductive%5C+isolation%5C+has%5C+been%5C+established%5C+between%5C+diploids%5C+and%5C+tetraploids.%5C+Based%5C+on%5C+two%5C+chloroplast%5C+DNA%5C+%5C%28cpDNA%5C%29%5C+fragments%5C+%5C%28petL%5C-psbE%2C%5C+trnQ%5C-rps16%5C%29%2C%5C+haplotypes%5C+were%5C+identified%5C+%2C%5C+and%5C+the%5C+origination%5C+of%5C+tetraploids%5C+were%5C+analyzed.%5C+The%5C+main%5C+results%5C+and%5C+conclusions%5C+are%5C+as%5C+follows%5C%3A%5C+1.%5C+Distribution%5C+of%5C+cytotypes%2C%5C+Cytotype%5C+distribution%5C+was%5C+analyzed%5C+based%5C+on%5C+412%5C+newly%5C+studied%5C+plants%5C+from%5C+seventeen%5C+populations%5C+and%5C+published%5C+literatures.%5C+Nine%5C+diploid%5C+populations%2C%5C+six%5C+diploid%5C-tetraploid%5C+mixed%5C+populations%5C+occur%5C+in%5C+central%5C+to%5C+northwest%5C+Yunnan%2C%5C+while%5C+twelve%5C+tetraploid%5C+populations%5C+occur%5C+in%5C+the%5C+Yunnan%5C-Guizhou%5C+Plateau.%5C+Furthermore%2C%5C+tetraploids%5C+has%5C+a%5C+wider%5C+altitude%5C+range%5C+%5C%281400%5C-3726%5C+m%5C%29%5C+than%5C+diploids%5C+%5C%282100%5C-3638%5C+m%5C%29%2C%5C+which%5C+suggests%5C+the%5C+adaptative%5C+ability%5C+of%5C+tetraploid%5C+is%5C+much%5C+stronger%5C+than%5C+its%5C+diploid%5C+pregnancies.%5C+Tetraploid%5C+populations%5C+distributed%5C+in%5C+northwest%5C+Yunnan%5C+have%5C+much%5C+lower%5C+karyotype%5C+asymmetry%5C+with%5C+the%5C+asymmetry%5C+indexes%5C+%5C%28AI%5C%29%5C+ranges%5C+from%5C+1.83%5C+to%5C+2.87%5C+compared%5C+to%5C+other%5C+populations%5C+of%5C+other%5C+areas%5C+%5C%28AI%2C%5C+2.03%5C-3.02%5C%29.%5C+This%5C+suggests%5C+tetraploid%5C+in%5C+northwest%5C+Yunnan%5C+is%5C+likely%5C+to%5C+have%5C+an%5C+earlier%5C+derivation.%5C+2.%5C+Autoploidization%5C+origin%5C+of%5C+the%5C+tetraploids%2C%5C+Diploids%5C+are%5C+all%5C+2A%5C+type%5C+except%5C+that%5C+Zhongdian%5C+D%5C+and%5C+Baoshan%5C+populations%5C+are%5C+3A%5C+type%2C%5C+and%5C+tetraploids%5C+are%5C+all%5C+2A%5C+type%5C+but%5C+Huize%5C+and%5C+Hezhang%5C+populations%5C+are%5C+2B%5C+type.%5C+It%5C+shows%5C+high%5C+similarity%5C+of%5C+karyotypes%5C+of%5C+diploid%5C+and%5C+tetraploids.%5C+In%5C+addition%2C%5C+the%5C+undistinguishable%5C+morphology%5C+of%5C+A.%5C+wallichii%5C+with%5C+different%5C+ploidy%5C+levels%5C+in%5C+northwest%5C+Yunnan%5C+and%5C+the%5C+monophyly%5C+of%5C+A.%5C+wallichii%5C+in%5C+ITS%5C+strict%5C+consensus%5C+tree%5C+all%5C+suggest%5C+autopolyploid%5C+origins%5C+of%5C+tetraploids%5C+A.%5C+wallichii.%5C+3.%5C+Multiple%5C+origins%5C+of%5C+tetraploids%2C%5C+Based%5C+on%5C+two%5C+cpDNA%5C+fragments%5C+%5C%28petL%5C-psbE%2C%5C+trnQ%5C-rps16%5C%29%5C+in%5C+85%5C+individuals%5C+from%5C+17%5C+populations%5C+across%5C+the%5C+Yunnan%5C-Guizhou%5C+Plateau%2C%5C+a%5C+total%5C+of%5C+17%5C+haplotypes%5C+were%5C+identified%2C%5C+among%5C+them%2C%5C+3%5C+in%5C+diploids%5C+only%2C%5C+11%5C+in%5C+tetraploids%5C+only%2C%5C+and%5C+3%5C+found%5C+in%5C+both%5C+cytotypes.%5C+This%2C%5C+plus%5C+network%5C+analyses%2C%5C+indicated%5C+that%5C+tetraploids%5C+have%5C+arisen%5C+independently%5C+from%5C+diploids%5C+at%5C+least%5C+three%5C+times.%5C+4.%5C+Productive%5C+isolation%5C+between%5C+diploids%5C+and%5C+teraploids%2C%5C+ITS%5C+phylogenetic%5C+analyses%5C+between%5C+diploid%5C+and%5C+tetraploid%5C+A.%5C+wallichii%5C+shows%5C+that%5C+diploids%5C+and%5C+tetraploids%5C+are%5C+both%5C+monophyly%2C%5C+with%5C+bootstrap%5C+value%5C+100%25%5C+and%5C+88%25%5C+respectively%2C%5C+indicating%5C+that%5C+the%5C+reproductive%5C+isolation%5C+has%5C+been%5C+established%5C+between%5C+them.%5C+Based%5C+on%5C+cpDNA%5C+haplotypes%5C+and%5C+ITS%5C+variation%5C+types%5C+analyses%2C%5C+extensive%5C+hybridization%5C+and%5C+gene%5C+introgression%5C+may%5C+have%5C+occurred%5C+among%5C+tetraploids."},{"jsname":"Sophora davidii (Franch.) Skeels is an endemic species to China, and widely distributed in the dry valleys of the Himalayan-Hengduan Mountain Systems, the Yungui Plateau, the Qinling Mountain, the Loess Plateau and other places of China. Previous studies of plant phylogeography have focused mainly on some taxa from the mountainous areas of China, relatively few studies have been conducted on plant taxa from the river valleys. The population dynamics and evolutionary history of species in such habitat remain less unknown, including the factors affecting the population genetic structure and its potential refugia in glaciation. In this study, we first determine the chromosome number, ploidy and karyotype of most populations we sampled. Then, based on sequence data from two maternally inherited cpDNA and one biparentally inherited nuclear DNA fragments, our study revealed the genetic diversity and population genetic structure of S. davidii and factors affecting them. The demographic history and potential refugia of this speices were investigated and the genetic relationship among three varieties was also clarified. The main results are summarized as follows:1. Cytogeography，The chromosome number and karyotypes of 14 S. davidii populations have been studied. The results showed that the choromosome number of all the populations is 2n = 18. The interphase nuclei and prophase chromosomes of the species were found to be of the complex chromosome type and interstitial type. The results of karyotype analysis showed that 7 of 14 materials has satellites, and the number and position of satellites differ among populations, and thus revealed a series of diversified karyotypes. With most populations being of ploidy, cytogenetical divergence within the species lied mainly in chromosome size and structure. The fact that polyploidization did not occur very often for variations in Southwest China was against viewpoint that polyploidization level in this area is higher than that of other distribution areas due to the elevation of mountains and plateau. 2. Phylogeographic analysisbased on chloroplast sequence，We sequenced two cpDNA fragments rpl32-trnL(UAG)intergenic spacer and trnH-psbA spacer in 40 populations sampled, recovering 22 chlorotypes. The average with-in population diversity (hS = 0.171) was much lower than total genetic diversity (hT = 0.857). Population differentiation was high (NST = 0.924, GST = 0.801) indicating low levels of seed-based gene flow and significant phylogeographical stucture (NST > GST, P < 0.05) were exhibited by this species. The SAMOVA revealed seven diverging groups of related chlorotypes, six of them had distinct nonoverlapping geographical ranges: one in the northeast comprising 10 populations, a second with a southeast distribution comprising 22 populations, and the remaning four groups comprising 15 populations located in the west part of the species’ range along different river valleys. The genetic clustering of populations into three regions was also supported by analysis of molecular variance, which showed that most genetic variation (82.43%) was found among these three regions. Two clusters were distinguished by both phylogenetic analysis and genealogical analysis of chlorotypes, one consisting of chlorotypes from the western region and the second consisting of those from the eastern region. Significant genetic differences between the two regions might be attributed to vicariance and restricted gene flow, and this vicariance could be explained by the physical environmental heterogeneity on each side of the Tanaka-Kaiyong Line. Following the uplift of the Tibetan Plateau, the reorganization of the major river drainages was primarily caused by river separation and capture events. These historical events could change the distribution of S. davidii from fragmented to continuous (Upper/Lower Jinshajiang and Yalongjiang/Daduhe), and from continuous to fragmented (Nujiang and Jinshajiang/Honghe). However, spatial and temporal patterns of phylogeographic divergence are strongly associated with historical disjunction rather than modern drainage connections. Moreover, the following north-south split in the eastern region and effective isolation with their genetic diversity were essentially modelled by genetic drift. The higher chlorotype richness and genetic divergence for populations in western region compared with other two regions suggests that there were multipe refugia or in situ survival of S. davidii in the Himalayan-Hengduan Mountain region. Fixation of chlorotypes in the northeastern region and near fixation in the southeastern region suggest a recent colonization of these areas. We further found that this species underwent past range expansion around 37-303 thousand years ago (kya). The southeastern populations likely experienced a demographic expansion via unidirectional gene flow along rivers, while northeastern populations underwent a more northward expansion, both from initial populations (s) (21, 22, 23) preserved on eastern refugia (Jinshajiang). This process might have been accompanied with a series of founder effects or bottlenecks making populations genetically impoverished. 3. Phylogeographic analysisbased on nuclear sequence，We sequenced the nuclear (ncpGS) region in all populations sampled, recovering 23 nuclear haplotypes. Compared to cpDNA, both NST (0.470) and GST (0.338) were relatively lower, but NST was also significantly larger than GST. 37.10% of the total variation was distributed among regions which was much lower than that shown by chlorotypes. Thus, more extensive distribution of nuclear haplotypes was exhibited across the geographical range instead of the strong population subdivision observed in chlorotypes. Similarly to the chloroplast data, we found that genetic differentiation of nDNA was positively correlated with the geographical distance, but the increase in the geographical distance between populations did not increase the genetic differentiation of nDNA as rapidly as that of cpDNA. These contrasting levels between the chloroplast and nuclear genomes of S. davidii are likely due to limited gene flow of cpDNA by seeds vs. the extensive gene flow of nDNA by wind-mediated pollen in the population history. We also determined from nuclear markers that haplotype diversity was reduced in the southeastern and northeastern regions due to the loss of rare haplotypes in western region. This reduction of gene diversity is also a signature of founder events or recent bottleneck during post-glacial colonization. However, nuclear diversity within populations remains high. This provides evidence that regionally pollen flow might be sufficiently high to blur the genetic identity of founder populations over a reasonably large spatial scale.3. Relationships among three varieties，The phylogenetic analysis identified two phylogroups of chlorotypes, corresponding to S. davidii var. davidii and var. chuansinesis. The former was distinguished by the abscence of predonminant nuclear haplotype H1 of the latter. The monophyletic group of chlorotypes in var. davidii and var. liangshanesis showed their relatively close relationship. And their genetic divergence from the third variety appears to be relative to their slight morphological difference in leaf size and the divergent environmental niche spaces they occupy. Thus, the observed differences in morphological characters between var. chuansinesis and other two varieties can be explained by the seed dispersal limitation illustrated above (as inferred by geographical separation) and by environmental heterogeneity (as inferred by precipitation or elevation) or by a combination of both. After all, the geological changes, drainage reorganization, and floristic differences following the Himalayan uplift have been suggested to affect the genetic structure of S. davidii. These results provide new insights into the phylogeographic pattern of plants in China. In addition, the unique population genetic structure found in S. davidii has provided important insights into the evolutionary history of this species. The genetic profile uncovered in this study is also critical for its conservation management. Our study has uncovered the existence of at least two ‘evolutionary significant units’ independent units within S. davidii, corresponding to var. davidii from eastern region and var. chuansinensis from western region. The conservation efforts should first focus on most western populations and on the southeastern ones exhibiting high levels of genetic diversity, while the genetically homogeneous northeastern populations located in the degraded Loess Plateau should require much greater conservation efforts.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3ASophora%5C+davidii%5C+%5C%28Franch.%5C%29%5C+Skeels%5C+is%5C+an%5C+endemic%5C+species%5C+to%5C+China%2C%5C+and%5C+widely%5C+distributed%5C+in%5C+the%5C+dry%5C+valleys%5C+of%5C+the%5C+Himalayan%5C-Hengduan%5C+Mountain%5C+Systems%2C%5C+the%5C+Yungui%5C+Plateau%2C%5C+the%5C+Qinling%5C+Mountain%2C%5C+the%5C+Loess%5C+Plateau%5C+and%5C+other%5C+places%5C+of%5C+China.%5C+Previous%5C+studies%5C+of%5C+plant%5C+phylogeography%5C+have%5C+focused%5C+mainly%5C+on%5C+some%5C+taxa%5C+from%5C+the%5C+mountainous%5C+areas%5C+of%5C+China%2C%5C+relatively%5C+few%5C+studies%5C+have%5C+been%5C+conducted%5C+on%5C+plant%5C+taxa%5C+from%5C+the%5C+river%5C+valleys.%5C+The%5C+population%5C+dynamics%5C+and%5C+evolutionary%5C+history%5C+of%5C+species%5C+in%5C+such%5C+habitat%5C+remain%5C+less%5C+unknown%2C%5C+including%5C+the%5C+factors%5C+affecting%5C+the%5C+population%5C+genetic%5C+structure%5C+and%5C+its%5C+potential%5C+refugia%5C+in%5C+glaciation.%5C+In%5C+this%5C+study%2C%5C+we%5C+first%5C+determine%5C+the%5C+chromosome%5C+number%2C%5C+ploidy%5C+and%5C+karyotype%5C+of%5C+most%5C+populations%5C+we%5C+sampled.%5C+Then%2C%5C+based%5C+on%5C+sequence%5C+data%5C+from%5C+two%5C+maternally%5C+inherited%5C+cpDNA%5C+and%5C+one%5C+biparentally%5C+inherited%5C+nuclear%5C+DNA%5C+fragments%2C%5C+our%5C+study%5C+revealed%5C+the%5C+genetic%5C+diversity%5C+and%5C+population%5C+genetic%5C+structure%5C+of%5C+S.%5C+davidii%5C+and%5C+factors%5C+affecting%5C+them.%5C+The%5C+demographic%5C+history%5C+and%5C+potential%5C+refugia%5C+of%5C+this%5C+speices%5C+were%5C+investigated%5C+and%5C+the%5C+genetic%5C+relationship%5C+among%5C+three%5C+varieties%5C+was%5C+also%5C+clarified.%5C+The%5C+main%5C+results%5C+are%5C+summarized%5C+as%5C+follows%5C%3A1.%5C+Cytogeography%EF%BC%8CThe%5C+chromosome%5C+number%5C+and%5C+karyotypes%5C+of%5C+14%5C+S.%5C+davidii%5C+populations%5C+have%5C+been%5C+studied.%5C+The%5C+results%5C+showed%5C+that%5C+the%5C+choromosome%5C+number%5C+of%5C+all%5C+the%5C+populations%5C+is%5C+2n%5C+%3D%5C+18.%5C+The%5C+interphase%5C+nuclei%5C+and%5C+prophase%5C+chromosomes%5C+of%5C+the%5C+species%5C+were%5C+found%5C+to%5C+be%5C+of%5C+the%5C+complex%5C+chromosome%5C+type%5C+and%5C+interstitial%5C+type.%5C+The%5C+results%5C+of%5C+karyotype%5C+analysis%5C+showed%5C+that%5C+7%5C+of%5C+14%5C+materials%5C+has%5C+satellites%2C%5C+and%5C+the%5C+number%5C+and%5C+position%5C+of%5C+satellites%5C+differ%5C+among%5C+populations%2C%5C+and%5C+thus%5C+revealed%5C+a%5C+series%5C+of%5C+diversified%5C+karyotypes.%5C+With%5C+most%5C+populations%5C+being%5C+of%5C+ploidy%2C%5C+cytogenetical%5C+divergence%5C+within%5C+the%5C+species%5C+lied%5C+mainly%5C+in%5C+chromosome%5C+size%5C+and%5C+structure.%5C+The%5C+fact%5C+that%5C+polyploidization%5C+did%5C+not%5C+occur%5C+very%5C+often%5C+for%5C+variations%5C+in%5C+Southwest%5C+China%5C+was%5C+against%5C+viewpoint%5C+that%5C+polyploidization%5C+level%5C+in%5C+this%5C+area%5C+is%5C+higher%5C+than%5C+that%5C+of%5C+other%5C+distribution%5C+areas%5C+due%5C+to%5C+the%5C+elevation%5C+of%5C+mountains%5C+and%5C+plateau.%5C+2.%5C+Phylogeographic%5C+analysisbased%5C+on%5C+chloroplast%5C+sequence%EF%BC%8CWe%5C+sequenced%5C+two%5C+cpDNA%5C+fragments%5C+rpl32%5C-trnL%5C%28UAG%5C%29intergenic%5C+spacer%5C+and%5C+trnH%5C-psbA%5C+spacer%5C+in%5C+40%5C+populations%5C+sampled%2C%5C+recovering%5C+22%5C+chlorotypes.%5C+The%5C+average%5C+with%5C-in%5C+population%5C+diversity%5C+%5C%28hS%5C+%3D%5C+0.171%5C%29%5C+was%5C+much%5C+lower%5C+than%5C+total%5C+genetic%5C+diversity%5C+%5C%28hT%5C+%3D%5C+0.857%5C%29.%5C+Population%5C+differentiation%5C+was%5C+high%5C+%5C%28NST%5C+%3D%5C+0.924%2C%5C+GST%5C+%3D%5C+0.801%5C%29%5C+indicating%5C+low%5C+levels%5C+of%5C+seed%5C-based%5C+gene%5C+flow%5C+and%5C+significant%5C+phylogeographical%5C+stucture%5C+%5C%28NST%5C+%3E%5C+GST%2C%5C+P%5C+%3C%5C+0.05%5C%29%5C+were%5C+exhibited%5C+by%5C+this%5C+species.%5C+The%5C+SAMOVA%5C+revealed%5C+seven%5C+diverging%5C+groups%5C+of%5C+related%5C+chlorotypes%2C%5C+six%5C+of%5C+them%5C+had%5C+distinct%5C+nonoverlapping%5C+geographical%5C+ranges%5C%3A%5C+one%5C+in%5C+the%5C+northeast%5C+comprising%5C+10%5C+populations%2C%5C+a%5C+second%5C+with%5C+a%5C+southeast%5C+distribution%5C+comprising%5C+22%5C+populations%2C%5C+and%5C+the%5C+remaning%5C+four%5C+groups%5C+comprising%5C+15%5C+populations%5C+located%5C+in%5C+the%5C+west%5C+part%5C+of%5C+the%5C+species%E2%80%99%5C+range%5C+along%5C+different%5C+river%5C+valleys.%5C+The%5C+genetic%5C+clustering%5C+of%5C+populations%5C+into%5C+three%5C+regions%5C+was%5C+also%5C+supported%5C+by%5C+analysis%5C+of%5C+molecular%5C+variance%2C%5C+which%5C+showed%5C+that%5C+most%5C+genetic%5C+variation%5C+%5C%2882.43%25%5C%29%5C+was%5C+found%5C+among%5C+these%5C+three%5C+regions.%5C+Two%5C+clusters%5C+were%5C+distinguished%5C+by%5C+both%5C+phylogenetic%5C+analysis%5C+and%5C+genealogical%5C+analysis%5C+of%5C+chlorotypes%2C%5C+one%5C+consisting%5C+of%5C+chlorotypes%5C+from%5C+the%5C+western%5C+region%5C+and%5C+the%5C+second%5C+consisting%5C+of%5C+those%5C+from%5C+the%5C+eastern%5C+region.%5C+Significant%5C+genetic%5C+differences%5C+between%5C+the%5C+two%5C+regions%5C+might%5C+be%5C+attributed%5C+to%5C+vicariance%5C+and%5C+restricted%5C+gene%5C+flow%2C%5C+and%5C+this%5C+vicariance%5C+could%5C+be%5C+explained%5C+by%5C+the%5C+physical%5C+environmental%5C+heterogeneity%5C+on%5C+each%5C+side%5C+of%5C+the%5C+Tanaka%5C-Kaiyong%5C+Line.%5C+Following%5C+the%5C+uplift%5C+of%5C+the%5C+Tibetan%5C+Plateau%2C%5C+the%5C+reorganization%5C+of%5C+the%5C+major%5C+river%5C+drainages%5C+was%5C+primarily%5C+caused%5C+by%5C+river%5C+separation%5C+and%5C+capture%5C+events.%5C+These%5C+historical%5C+events%5C+could%5C+change%5C+the%5C+distribution%5C+of%5C+S.%5C+davidii%5C+from%5C+fragmented%5C+to%5C+continuous%5C+%5C%28Upper%5C%2FLower%5C+Jinshajiang%5C+and%5C+Yalongjiang%5C%2FDaduhe%5C%29%2C%5C+and%5C+from%5C+continuous%5C+to%5C+fragmented%5C+%5C%28Nujiang%5C+and%5C+Jinshajiang%5C%2FHonghe%5C%29.%5C+However%2C%5C+spatial%5C+and%5C+temporal%5C+patterns%5C+of%5C+phylogeographic%5C+divergence%5C+are%5C+strongly%5C+associated%5C+with%5C+historical%5C+disjunction%5C+rather%5C+than%5C+modern%5C+drainage%5C+connections.%5C+Moreover%2C%5C+the%5C+following%5C+north%5C-south%5C+split%5C+in%5C+the%5C+eastern%5C+region%5C+and%5C+effective%5C+isolation%5C+with%5C+their%5C+genetic%5C+diversity%5C+were%5C+essentially%5C+modelled%5C+by%5C+genetic%5C+drift.%5C+The%5C+higher%5C+chlorotype%5C+richness%5C+and%5C+genetic%5C+divergence%5C+for%5C+populations%5C+in%5C+western%5C+region%5C+compared%5C+with%5C+other%5C+two%5C+regions%5C+suggests%5C+that%5C+there%5C+were%5C+multipe%5C+refugia%5C+or%5C+in%5C+situ%5C+survival%5C+of%5C+S.%5C+davidii%5C+in%5C+the%5C+Himalayan%5C-Hengduan%5C+Mountain%5C+region.%5C+Fixation%5C+of%5C+chlorotypes%5C+in%5C+the%5C+northeastern%5C+region%5C+and%5C+near%5C+fixation%5C+in%5C+the%5C+southeastern%5C+region%5C+suggest%5C+a%5C+recent%5C+colonization%5C+of%5C+these%5C+areas.%5C+We%5C+further%5C+found%5C+that%5C+this%5C+species%5C+underwent%5C+past%5C+range%5C+expansion%5C+around%5C+37%5C-303%5C+thousand%5C+years%5C+ago%5C+%5C%28kya%5C%29.%5C+The%5C+southeastern%5C+populations%5C+likely%5C+experienced%5C+a%5C+demographic%5C+expansion%5C+via%5C+unidirectional%5C+gene%5C+flow%5C+along%5C+rivers%2C%5C+while%5C+northeastern%5C+populations%5C+underwent%5C+a%5C+more%5C+northward%5C+expansion%2C%5C+both%5C+from%5C+initial%5C+populations%5C+%5C%28s%5C%29%5C+%5C%2821%2C%5C+22%2C%5C+23%5C%29%5C+preserved%5C+on%5C+eastern%5C+refugia%5C+%5C%28Jinshajiang%5C%29.%5C+This%5C+process%5C+might%5C+have%5C+been%5C+accompanied%5C+with%5C+a%5C+series%5C+of%5C+founder%5C+effects%5C+or%5C+bottlenecks%5C+making%5C+populations%5C+genetically%5C+impoverished.%5C+3.%5C+Phylogeographic%5C+analysisbased%5C+on%5C+nuclear%5C+sequence%EF%BC%8CWe%5C+sequenced%5C+the%5C+nuclear%5C+%5C%28ncpGS%5C%29%5C+region%5C+in%5C+all%5C+populations%5C+sampled%2C%5C+recovering%5C+23%5C+nuclear%5C+haplotypes.%5C+Compared%5C+to%5C+cpDNA%2C%5C+both%5C+NST%5C+%5C%280.470%5C%29%5C+and%5C+GST%5C+%5C%280.338%5C%29%5C+were%5C+relatively%5C+lower%2C%5C+but%5C+NST%5C+was%5C+also%5C+significantly%5C+larger%5C+than%5C+GST.%5C+37.10%25%5C+of%5C+the%5C+total%5C+variation%5C+was%5C+distributed%5C+among%5C+regions%5C+which%5C+was%5C+much%5C+lower%5C+than%5C+that%5C+shown%5C+by%5C+chlorotypes.%5C+Thus%2C%5C+more%5C+extensive%5C+distribution%5C+of%5C+nuclear%5C+haplotypes%5C+was%5C+exhibited%5C+across%5C+the%5C+geographical%5C+range%5C+instead%5C+of%5C+the%5C+strong%5C+population%5C+subdivision%5C+observed%5C+in%5C+chlorotypes.%5C+Similarly%5C+to%5C+the%5C+chloroplast%5C+data%2C%5C+we%5C+found%5C+that%5C+genetic%5C+differentiation%5C+of%5C+nDNA%5C+was%5C+positively%5C+correlated%5C+with%5C+the%5C+geographical%5C+distance%2C%5C+but%5C+the%5C+increase%5C+in%5C+the%5C+geographical%5C+distance%5C+between%5C+populations%5C+did%5C+not%5C+increase%5C+the%5C+genetic%5C+differentiation%5C+of%5C+nDNA%5C+as%5C+rapidly%5C+as%5C+that%5C+of%5C+cpDNA.%5C+These%5C+contrasting%5C+levels%5C+between%5C+the%5C+chloroplast%5C+and%5C+nuclear%5C+genomes%5C+of%5C+S.%5C+davidii%5C+are%5C+likely%5C+due%5C+to%5C+limited%5C+gene%5C+flow%5C+of%5C+cpDNA%5C+by%5C+seeds%5C+vs.%5C+the%5C+extensive%5C+gene%5C+flow%5C+of%5C+nDNA%5C+by%5C+wind%5C-mediated%5C+pollen%5C+in%5C+the%5C+population%5C+history.%5C+We%5C+also%5C+determined%5C+from%5C+nuclear%5C+markers%5C+that%5C+haplotype%5C+diversity%5C+was%5C+reduced%5C+in%5C+the%5C+southeastern%5C+and%5C+northeastern%5C+regions%5C+due%5C+to%5C+the%5C+loss%5C+of%5C+rare%5C+haplotypes%5C+in%5C+western%5C+region.%5C+This%5C+reduction%5C+of%5C+gene%5C+diversity%5C+is%5C+also%5C+a%5C+signature%5C+of%5C+founder%5C+events%5C+or%5C+recent%5C+bottleneck%5C+during%5C+post%5C-glacial%5C+colonization.%5C+However%2C%5C+nuclear%5C+diversity%5C+within%5C+populations%5C+remains%5C+high.%5C+This%5C+provides%5C+evidence%5C+that%5C+regionally%5C+pollen%5C+flow%5C+might%5C+be%5C+sufficiently%5C+high%5C+to%5C+blur%5C+the%5C+genetic%5C+identity%5C+of%5C+founder%5C+populations%5C+over%5C+a%5C+reasonably%5C+large%5C+spatial%5C+scale.3.%5C+Relationships%5C+among%5C+three%5C+varieties%EF%BC%8CThe%5C+phylogenetic%5C+analysis%5C+identified%5C+two%5C+phylogroups%5C+of%5C+chlorotypes%2C%5C+corresponding%5C+to%5C+S.%5C+davidii%5C+var.%5C+davidii%5C+and%5C+var.%5C+chuansinesis.%5C+The%5C+former%5C+was%5C+distinguished%5C+by%5C+the%5C+abscence%5C+of%5C+predonminant%5C+nuclear%5C+haplotype%5C+H1%5C+of%5C+the%5C+latter.%5C+The%5C+monophyletic%5C+group%5C+of%5C+chlorotypes%5C+in%5C+var.%5C+davidii%5C+and%5C+var.%5C+liangshanesis%5C+showed%5C+their%5C+relatively%5C+close%5C+relationship.%5C+And%5C+their%5C+genetic%5C+divergence%5C+from%5C+the%5C+third%5C+variety%5C+appears%5C+to%5C+be%5C+relative%5C+to%5C+their%5C+slight%5C+morphological%5C+difference%5C+in%5C+leaf%5C+size%5C+and%5C+the%5C+divergent%5C+environmental%5C+niche%5C+spaces%5C+they%5C+occupy.%5C+Thus%2C%5C+the%5C+observed%5C+differences%5C+in%5C+morphological%5C+characters%5C+between%5C+var.%5C+chuansinesis%5C+and%5C+other%5C+two%5C+varieties%5C+can%5C+be%5C+explained%5C+by%5C+the%5C+seed%5C+dispersal%5C+limitation%5C+illustrated%5C+above%5C+%5C%28as%5C+inferred%5C+by%5C+geographical%5C+separation%5C%29%5C+and%5C+by%5C+environmental%5C+heterogeneity%5C+%5C%28as%5C+inferred%5C+by%5C+precipitation%5C+or%5C+elevation%5C%29%5C+or%5C+by%5C+a%5C+combination%5C+of%5C+both.%5C+After%5C+all%2C%5C+the%5C+geological%5C+changes%2C%5C+drainage%5C+reorganization%2C%5C+and%5C+floristic%5C+differences%5C+following%5C+the%5C+Himalayan%5C+uplift%5C+have%5C+been%5C+suggested%5C+to%5C+affect%5C+the%5C+genetic%5C+structure%5C+of%5C+S.%5C+davidii.%5C+These%5C+results%5C+provide%5C+new%5C+insights%5C+into%5C+the%5C+phylogeographic%5C+pattern%5C+of%5C+plants%5C+in%5C+China.%5C+In%5C+addition%2C%5C+the%5C+unique%5C+population%5C+genetic%5C+structure%5C+found%5C+in%5C+S.%5C+davidii%5C+has%5C+provided%5C+important%5C+insights%5C+into%5C+the%5C+evolutionary%5C+history%5C+of%5C+this%5C+species.%5C+The%5C+genetic%5C+profile%5C+uncovered%5C+in%5C+this%5C+study%5C+is%5C+also%5C+critical%5C+for%5C+its%5C+conservation%5C+management.%5C+Our%5C+study%5C+has%5C+uncovered%5C+the%5C+existence%5C+of%5C+at%5C+least%5C+two%5C+%E2%80%98evolutionary%5C+significant%5C+units%E2%80%99%5C+independent%5C+units%5C+within%5C+S.%5C+davidii%2C%5C+corresponding%5C+to%5C+var.%5C+davidii%5C+from%5C+eastern%5C+region%5C+and%5C+var.%5C+chuansinensis%5C+from%5C+western%5C+region.%5C+The%5C+conservation%5C+efforts%5C+should%5C+first%5C+focus%5C+on%5C+most%5C+western%5C+populations%5C+and%5C+on%5C+the%5C+southeastern%5C+ones%5C+exhibiting%5C+high%5C+levels%5C+of%5C+genetic%5C+diversity%2C%5C+while%5C+the%5C+genetically%5C+homogeneous%5C+northeastern%5C+populations%5C+located%5C+in%5C+the%5C+degraded%5C+Loess%5C+Plateau%5C+should%5C+require%5C+much%5C+greater%5C+conservation%5C+efforts."},{"jsname":"Thailand Research Fund (TRF)[RSA5980068]","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3AThailand%5C+Research%5C+Fund%5C+%5C%28TRF%5C%29%5C%5BRSA5980068%5C%5D"},{"jsname":"The origin center and diversity center of the genus Ligularia were considered to be central China and Hengduan Mountains Region (HMR) of China, respectively. In this research, we studied the phylogeographic pattern of L. hodgsonii and L. tongolensis, which was distributed in the origin center and diversity center, respectively. We aimed to infer the evolutionary process of Ligularia species. 1. The phylogeography of L. hodgsonii，Here, we investigated the phylogeographic history of L. hodgsonii disjunctively distributed in China and Japan. Two hundred and eighty individuals were collected from 29 natural populations, 23 located in China and 6 in Japan. A total of 19 haplotypes were identified with the combination of three chloroplast DNA (cpDNA) sequences variations (trnQ-5’rps16, trnL-rpl32 and psbA-trnH). At the species level, a high level of haplotype diversity (Hd) and total genetic diversity (HT) was detected. However, the average intrapopulation diversity (HS) was very low. Consequently, the population differentiation(NST = 0.989, GST = 0.933 ) was pronounced with a significant phylogeographic structure (NST > GST, p < 0.01). At the regional level, Chinese and Japanese L. hodgsonii had a similar estimate of genetic diversity (China: Hd = 0.847, HT = 0.869; Japan: Hd = 0.766, HT = 0.867). Populations from China and Japan possess unique sets of haplotypes, and no haplotypes were shared between the regions. Furthermore, both the phyloegenetic and network analyses recovered the haplotypes of China and Japan as two distinct clades. Thus, we suggested the disjunct distribution of L. hodgsonii in China and Japan may present the climatic vicariant relicts of the ancient widely distributed populations. After divergence, this species within each region experienced independent evolutionary process. In China, L. hodgsonii was distributed around the Sichuan Basin. This distribution range can be divided into five regions. They were Jiajin Mountain region, E’mei Mountain region, Yunnan-Guizhou Plateau region, Wushan-Wuling Mountain region and Qinling Mountain region. Twelve haplotypes were indentified within these regions. Each region had its own specific haplotypes, which had different ancestry in the network. We deduced that Chinese L. hodgsonii might survive the LGM in multiple isolated refugia around the Sichuan Basin. In Japan, L. hodgsonii was disjunctively distributed in northern Honshu and Hokkaido. Seven haplotypes were identified within this region. However, the genetic diversity in Honshu (Hd = 0.821) was much higher than that in Hokkaido (Hd = 0.513). And all haplotypes in Hokkaido were derived from Honshu. This haplotype distribution suggested that the northern Honshu could have served as refuge in Japan. Nested clade analysis (NCA) indicated multiple forces including the vicariance and long-distance dispersal affected the disjunctive distribution among populations of L. hodgsonii in Japan.2. The phylogeography of L. tongolensis，Ligularia tongolensis was distributed along the Jinshajiang watershed, Yalongjiang watershed and Wumeng Mountain. In order to deduce the demographic history of this species, we sequenced two chloroplast DNA (cpDNA) intergenic spacers (trnQ-5’rps16, trnL-rpl32) in 140 individuals from 14 populations of three groups (Jinshajiang vs. Yalongjiang vs. Wumeng) within this species range. High levels of haplotype diversity (Hd = 0.814) and total genetic diversity (HT = 0.862) were detected at the species level, based on a total oftwelve haplotypes identified. However, the intrapopulation diversity (HS = 0.349) was low, which led to the high levels of genetic divergence (GST = 0.595, NST = 0.614, FST = 0.597). In consideration of the speciation of L. tongolensis resulting from the uplifts of the Qinghai-Tibetan Plateau (QTP), we thought the present genetic structure of L. tongolensis was shaped by the fragmentation of ancestral populations during the courses of QTP uplifts. This was further supported by the absence of IBD tests (r = –0.291, p = 0.964), which suggest that the differentiation had not occurred in accordance with the isolation by distance model. The genetic differentiation in L. tongolensis appears to be associated with historical events. Meanwhile, H2 and H5, the dominant haplotypes that located on internal nodes and deviated from extinct ancestral haplotype in the network, were detected to be shared between Jinshajiang and Yalongjiang groups. We deduced that ancestral populations of this species might have had a continuous distribution range, which was then fragmented and isolated by the following tectonic events. Finally, the ancestral polymorphism, H2 and H5, were randomly allocated in Jinshajiang watershed and Yalongjiang watershed. Meanwhile, H5 was the dominant haplotype in Jinshajiang watershed; H7 was the domiant haplotype in Yalongjiang watershed and Wumeng Mountain. This haplotype distribution pattern indicated that each group might have served as a refuge for L. tongolensis during the Quaternary Glaciation. Postglacial demographic expansion was supported by unimodal mismatch distribution and star-like phylogenies, with expansion ages of 274 ka B. P. for this species","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3AThe%5C+origin%5C+center%5C+and%5C+diversity%5C+center%5C+of%5C+the%5C+genus%5C+Ligularia%5C+were%5C+considered%5C+to%5C+be%5C+central%5C+China%5C+and%5C+Hengduan%5C+Mountains%5C+Region%5C+%5C%28HMR%5C%29%5C+of%5C+China%2C%5C+respectively.%5C+In%5C+this%5C+research%2C%5C+we%5C+studied%5C+the%5C+phylogeographic%5C+pattern%5C+of%5C+L.%5C+hodgsonii%5C+and%5C+L.%5C+tongolensis%2C%5C+which%5C+was%5C+distributed%5C+in%5C+the%5C+origin%5C+center%5C+and%5C+diversity%5C+center%2C%5C+respectively.%5C+We%5C+aimed%5C+to%5C+infer%5C+the%5C+evolutionary%5C+process%5C+of%5C+Ligularia%5C+species.%5C+1.%5C+The%5C+phylogeography%5C+of%5C+L.%5C+hodgsonii%EF%BC%8CHere%2C%5C+we%5C+investigated%5C+the%5C+phylogeographic%5C+history%5C+of%5C+L.%5C+hodgsonii%5C+disjunctively%5C+distributed%5C+in%5C+China%5C+and%5C+Japan.%5C+Two%5C+hundred%5C+and%5C+eighty%5C+individuals%5C+were%5C+collected%5C+from%5C+29%5C+natural%5C+populations%2C%5C+23%5C+located%5C+in%5C+China%5C+and%5C+6%5C+in%5C+Japan.%5C+A%5C+total%5C+of%5C+19%5C+haplotypes%5C+were%5C+identified%5C+with%5C+the%5C+combination%5C+of%5C+three%5C+chloroplast%5C+DNA%5C+%5C%28cpDNA%5C%29%5C+sequences%5C+variations%5C+%5C%28trnQ%5C-5%E2%80%99rps16%2C%5C+trnL%5C-rpl32%5C+and%5C+psbA%5C-trnH%5C%29.%5C+At%5C+the%5C+species%5C+level%2C%5C+a%5C+high%5C+level%5C+of%5C+haplotype%5C+diversity%5C+%5C%28Hd%5C%29%5C+and%C2%A0total%5C+genetic%5C+diversity%5C+%5C%28HT%5C%29%5C+was%5C+detected.%5C+However%2C%5C+the%5C+average%5C+intrapopulation%5C+diversity%5C+%5C%28HS%5C%29%5C+was%5C+very%5C+low.%5C+Consequently%2C%5C+the%5C+population%5C+differentiation%5C%28NST%5C+%3D%5C+0.989%2C%5C+GST%5C+%3D%5C+0.933%5C+%5C%29%5C+was%5C+pronounced%5C+with%5C+a%5C+significant%5C+phylogeographic%5C+structure%5C+%5C%28NST%5C+%3E%5C+GST%2C%5C+p%5C+%3C%5C+0.01%5C%29.%5C+At%5C+the%5C+regional%5C+level%2C%5C+Chinese%5C+and%5C+Japanese%5C+L.%5C+hodgsonii%5C+had%5C+a%5C+similar%5C+estimate%5C+of%5C+genetic%5C+diversity%5C+%5C%28China%5C%3A%5C+Hd%5C+%3D%5C+0.847%2C%5C+HT%5C+%3D%5C+0.869%5C%3B%5C+Japan%5C%3A%5C+Hd%5C+%3D%5C+0.766%2C%5C+HT%5C+%3D%5C+0.867%5C%29.%5C+Populations%5C+from%5C+China%5C+and%5C+Japan%5C+possess%5C+unique%5C+sets%5C+of%5C+haplotypes%2C%5C+and%5C+no%5C+haplotypes%5C+were%5C+shared%5C+between%5C+the%5C+regions.%5C+Furthermore%2C%5C+both%5C+the%5C+phyloegenetic%5C+and%5C+network%5C+analyses%5C+recovered%5C+the%5C+haplotypes%5C+of%5C+China%5C+and%5C+Japan%5C+as%5C+two%5C+distinct%5C+clades.%5C+Thus%2C%5C+we%5C+suggested%5C+the%5C+disjunct%5C+distribution%5C+of%5C+L.%5C+hodgsonii%5C+in%5C+China%5C+and%5C+Japan%5C+may%5C+present%5C+the%5C+climatic%5C+vicariant%5C+relicts%5C+of%5C+the%5C+ancient%5C+widely%5C+distributed%5C+populations.%5C+After%5C+divergence%2C%5C+this%5C+species%5C+within%5C+each%5C+region%5C+experienced%5C+independent%5C+evolutionary%5C+process.%5C+In%5C+China%2C%5C+L.%5C+hodgsonii%5C+was%5C+distributed%5C+around%5C+the%5C+Sichuan%5C+Basin.%5C+This%5C+distribution%5C+range%5C+can%5C+be%5C+divided%5C+into%5C+five%5C+regions.%5C+They%5C+were%5C+Jiajin%5C+Mountain%5C+region%2C%5C+E%E2%80%99mei%5C+Mountain%5C+region%2C%5C+Yunnan%5C-Guizhou%5C+Plateau%5C+region%2C%5C+Wushan%5C-Wuling%5C+Mountain%5C+region%5C+and%5C+Qinling%5C+Mountain%5C+region.%5C+Twelve%5C+haplotypes%5C+were%5C+indentified%5C+within%5C+these%5C+regions.%5C+Each%5C+region%5C+had%5C+its%5C+own%5C+specific%5C+haplotypes%2C%5C+which%5C+had%5C+different%5C+ancestry%5C+in%5C+the%5C+network.%5C+We%5C+deduced%5C+that%5C+Chinese%5C+L.%5C+hodgsonii%5C+might%5C+survive%5C+the%5C+LGM%5C+in%5C+multiple%5C+isolated%5C+refugia%5C+around%5C+the%5C+Sichuan%5C+Basin.%5C+In%5C+Japan%2C%5C+L.%5C+hodgsonii%5C+was%5C+disjunctively%5C+distributed%5C+in%5C+northern%5C+Honshu%5C+and%5C+Hokkaido.%5C+Seven%5C+haplotypes%5C+were%5C+identified%5C+within%5C+this%5C+region.%5C+However%2C%5C+the%5C+genetic%5C+diversity%5C+in%5C+Honshu%5C+%5C%28Hd%5C+%3D%5C+0.821%5C%29%5C+was%5C+much%5C+higher%5C+than%5C+that%5C+in%5C+Hokkaido%5C+%5C%28Hd%5C+%3D%5C+0.513%5C%29.%5C+And%5C+all%5C+haplotypes%5C+in%5C+Hokkaido%5C+were%5C+derived%5C+from%5C+Honshu.%5C+This%5C+haplotype%5C+distribution%5C+suggested%5C+that%5C+the%5C+northern%5C+Honshu%5C+could%5C+have%5C+served%5C+as%5C+refuge%5C+in%5C+Japan.%5C+Nested%5C+clade%5C+analysis%5C+%5C%28NCA%5C%29%5C+indicated%5C+multiple%5C+forces%5C+including%5C+the%5C+vicariance%5C+and%5C+long%5C-distance%5C+dispersal%5C+affected%5C+the%5C+disjunctive%5C+distribution%5C+among%5C+populations%5C+of%5C+L.%5C+hodgsonii%5C+in%5C+Japan.2.%5C+The%5C+phylogeography%5C+of%5C+L.%5C+tongolensis%EF%BC%8CLigularia%5C+tongolensis%5C+was%5C+distributed%5C+along%5C+the%5C+Jinshajiang%5C+watershed%2C%5C+Yalongjiang%5C+watershed%5C+and%5C+Wumeng%5C+Mountain.%5C+In%5C+order%5C+to%5C+deduce%5C+the%5C+demographic%5C+history%5C+of%5C+this%5C+species%2C%5C+we%5C+sequenced%5C+two%5C+chloroplast%5C+DNA%5C+%5C%28cpDNA%5C%29%5C+intergenic%5C+spacers%5C+%5C%28trnQ%5C-5%E2%80%99rps16%2C%5C+trnL%5C-rpl32%5C%29%5C+in%5C+140%5C+individuals%5C+from%5C+14%5C+populations%5C+of%5C+three%5C+groups%5C+%5C%28Jinshajiang%5C+vs.%5C+Yalongjiang%5C+vs.%5C+Wumeng%5C%29%5C+within%5C+this%5C+species%5C+range.%5C+High%5C+levels%5C+of%5C+haplotype%5C+diversity%5C+%5C%28Hd%5C+%3D%5C+0.814%5C%29%5C+and%5C+total%5C+genetic%5C+diversity%5C+%5C%28HT%5C+%3D%5C+0.862%5C%29%5C+were%5C+detected%5C+at%5C+the%5C+species%5C+level%2C%5C+based%5C+on%5C+a%5C+total%5C+oftwelve%5C+haplotypes%5C+identified.%5C+However%2C%5C+the%5C+intrapopulation%5C+diversity%5C+%5C%28HS%5C+%3D%5C+0.349%5C%29%5C+was%5C+low%2C%5C+which%5C+led%5C+to%5C+the%5C+high%5C+levels%5C+of%5C+genetic%5C+divergence%5C+%5C%28GST%5C+%3D%5C+0.595%2C%5C+NST%5C+%3D%5C+0.614%2C%5C+FST%5C+%3D%5C+0.597%5C%29.%5C+In%5C+consideration%5C+of%5C+the%5C+speciation%5C+of%5C+L.%5C+tongolensis%5C+resulting%5C+from%5C+the%5C+uplifts%5C+of%5C+the%5C+Qinghai%5C-Tibetan%5C+Plateau%5C+%5C%28QTP%5C%29%2C%5C+we%5C+thought%5C+the%5C+present%5C+genetic%5C+structure%5C+of%5C+L.%5C+tongolensis%5C+was%5C+shaped%5C+by%5C+the%5C+fragmentation%5C+of%5C+ancestral%5C+populations%5C+during%5C+the%5C+courses%5C+of%5C+QTP%5C+uplifts.%5C+This%5C+was%5C+further%5C+supported%5C+by%5C+the%5C+absence%5C+of%5C+IBD%5C+tests%5C+%5C%28r%5C+%3D%5C+%E2%80%930.291%2C%5C+p%5C+%3D%5C+0.964%5C%29%2C%5C+which%5C+suggest%5C+that%5C+the%5C+differentiation%5C+had%5C+not%5C+occurred%5C+in%5C+accordance%5C+with%5C+the%5C+isolation%5C+by%5C+distance%5C+model.%5C+The%5C+genetic%5C+differentiation%5C+in%5C+L.%5C+tongolensis%5C+appears%5C+to%5C+be%5C+associated%5C+with%5C+historical%5C+events.%5C+Meanwhile%2C%5C+H2%5C+and%5C+H5%2C%5C+the%5C+dominant%5C+haplotypes%5C+that%5C+located%5C+on%5C+internal%5C+nodes%5C+and%5C+deviated%5C+from%5C+extinct%5C+ancestral%5C+haplotype%5C+in%5C+the%5C+network%2C%5C+were%5C+detected%5C+to%5C+be%5C+shared%5C+between%5C+Jinshajiang%5C+and%5C+Yalongjiang%5C+groups.%5C+We%5C+deduced%5C+that%5C+ancestral%5C+populations%5C+of%5C+this%5C+species%5C+might%5C+have%5C+had%5C+a%5C+continuous%5C+distribution%5C+range%2C%5C+which%5C+was%5C+then%5C+fragmented%5C+and%5C+isolated%5C+by%5C+the%5C+following%5C+tectonic%5C+events.%5C+Finally%2C%5C+the%5C+ancestral%5C+polymorphism%2C%5C+H2%5C+and%5C+H5%2C%5C+were%5C+randomly%5C+allocated%5C+in%5C+Jinshajiang%5C+watershed%5C+and%5C+Yalongjiang%5C+watershed.%5C+Meanwhile%2C%5C+H5%5C+was%5C+the%5C+dominant%5C+haplotype%5C+in%5C+Jinshajiang%5C+watershed%5C%3B%5C+H7%5C+was%5C+the%5C+domiant%5C+haplotype%5C+in%5C+Yalongjiang%5C+watershed%5C+and%5C+Wumeng%5C+Mountain.%5C+This%5C+haplotype%5C+distribution%5C+pattern%5C+indicated%5C+that%5C+each%5C+group%5C+might%5C+have%5C+served%5C+as%5C+a%5C+refuge%5C+for%5C+L.%5C+tongolensis%5C+during%5C+the%5C+Quaternary%5C+Glaciation.%5C+Postglacial%5C+demographic%5C+expansion%5C+was%5C+supported%5C+by%5C+unimodal%5C+mismatch%5C+distribution%5C+and%5C+star%5C-like%5C+phylogenies%2C%5C+with%5C+expansion%5C+ages%5C+of%5C+274%5C+ka%5C+B.%5C+P.%5C+for%5C+this%5C+species"},{"jsname":"The temperate woody bamboos are a morphologically diverse group with a complicated taxonomy. The Arundinaria group has an East Asia-North America disjunct distribution, which is one of those with complex taxonomy in the temperate woody bamboos. In this study, the phylogeny of the temperate woody bamboos was reconstructed based on eight non-coding regions of the chloroplast genome and nuclear gene GBSSI using large sample set (124 species in 24 genera) with an emphasis on the Arundinaria group. The monophyly of the temperate woody bamboos was resolved in all phylogenies. Ten major lineages were obtained in the chloroplast phylogeny with unresolved relationships among them; the recovered phylogeny is strongly incongruent with the classifications based on morphology at both subtribal and generic ranks; some subclades that are related to the geographic distribution were obtained in those lineages. Five lineages in the GBSSI gene phylogeny were recovered as the same in the chloroplast phylogeny, and the other lineages were incongruent with chloroplast phylogeny in some ways. The reticulate evolution caused by hybridization, introgression and lineage sorting may be an explanation for the molecular phylogenetic incongruence. Based on the facts of diverse morphology, broad distribution and molecular phylogeny, we inferred that the major clades and species within most of the clades of the temperate woody bamboos were originated during several rapid adaptive radiations. Ten putative hybrids were discussed based on molecular phylogenies, morphology and distribution. The micromorphology of the leaf epidermis under SEM (scanning electron microscope) was observed and divided into nine types; the micromorphology can provide some evidence for the bamboo taxonomy and inference of putative hybrids. Additionally, taxonomic revisions were presented for some species based on field observation and herbarium work.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3AThe%5C+temperate%5C+woody%5C+bamboos%5C+are%5C+a%5C+morphologically%5C+diverse%5C+group%5C+with%5C+a%5C+complicated%5C+taxonomy.%5C+The%5C+Arundinaria%5C+group%5C+has%5C+an%5C+East%5C+Asia%5C-North%5C+America%5C+disjunct%5C+distribution%2C%5C+which%5C+is%5C+one%5C+of%5C+those%5C+with%5C+complex%5C+taxonomy%5C+in%5C+the%5C+temperate%5C+woody%5C+bamboos.%5C+In%5C+this%5C+study%2C%5C+the%5C+phylogeny%5C+of%5C+the%5C+temperate%5C+woody%5C+bamboos%5C+was%5C+reconstructed%5C+based%5C+on%5C+eight%5C+non%5C-coding%5C+regions%5C+of%5C+the%5C+chloroplast%5C+genome%5C+and%5C+nuclear%5C+gene%5C+GBSSI%5C+using%5C+large%5C+sample%5C+set%5C+%5C%28124%5C+species%5C+in%5C+24%5C+genera%5C%29%5C+with%5C+an%5C+emphasis%5C+on%5C+the%5C+Arundinaria%5C+group.%5C+The%5C+monophyly%5C+of%5C+the%5C+temperate%5C+woody%5C+bamboos%5C+was%5C+resolved%5C+in%5C+all%5C+phylogenies.%5C+Ten%5C+major%5C+lineages%5C+were%5C+obtained%5C+in%5C+the%5C+chloroplast%5C+phylogeny%5C+with%5C+unresolved%5C+relationships%5C+among%5C+them%5C%3B%5C+the%5C+recovered%5C+phylogeny%5C+is%5C+strongly%5C+incongruent%5C+with%5C+the%5C+classifications%5C+based%5C+on%5C+morphology%5C+at%5C+both%5C+subtribal%5C+and%5C+generic%5C+ranks%5C%3B%5C+some%5C+subclades%5C+that%5C+are%5C+related%5C+to%5C+the%5C+geographic%5C+distribution%5C+were%5C+obtained%5C+in%5C+those%5C+lineages.%5C+Five%5C+lineages%5C+in%5C+the%5C+GBSSI%5C+gene%5C+phylogeny%5C+were%5C+recovered%5C+as%5C+the%5C+same%5C+in%5C+the%5C+chloroplast%5C+phylogeny%2C%5C+and%5C+the%5C+other%5C+lineages%5C+were%5C+incongruent%5C+with%5C+chloroplast%5C+phylogeny%5C+in%5C+some%5C+ways.%5C+The%5C+reticulate%5C+evolution%5C+caused%5C+by%5C+hybridization%2C%5C+introgression%5C+and%5C+lineage%5C+sorting%5C+may%5C+be%5C+an%5C+explanation%5C+for%5C+the%5C+molecular%5C+phylogenetic%5C+incongruence.%5C+Based%5C+on%5C+the%5C+facts%5C+of%5C+diverse%5C+morphology%2C%5C+broad%5C+distribution%5C+and%5C+molecular%5C+phylogeny%2C%5C+we%5C+inferred%5C+that%5C+the%5C+major%5C+clades%5C+and%5C+species%5C+within%5C+most%5C+of%5C+the%5C+clades%5C+of%5C+the%5C+temperate%5C+woody%5C+bamboos%5C+were%5C+originated%5C+during%5C+several%5C+rapid%5C+adaptive%5C+radiations.%5C+Ten%5C+putative%5C+hybrids%5C+were%5C+discussed%5C+based%5C+on%5C+molecular%5C+phylogenies%2C%5C+morphology%5C+and%5C+distribution.%5C+The%5C+micromorphology%5C+of%5C+the%5C+leaf%5C+epidermis%5C+under%5C+SEM%5C+%5C%28scanning%5C+electron%5C+microscope%5C%29%5C+was%5C+observed%5C+and%5C+divided%5C+into%5C+nine%5C+types%5C%3B%5C+the%5C+micromorphology%5C+can%5C+provide%5C+some%5C+evidence%5C+for%5C+the%5C+bamboo%5C+taxonomy%5C+and%5C+inference%5C+of%5C+putative%5C+hybrids.%5C+Additionally%2C%5C+taxonomic%5C+revisions%5C+were%5C+presented%5C+for%5C+some%5C+species%5C+based%5C+on%5C+field%5C+observation%5C+and%5C+herbarium%5C+work."},{"jsname":"Through investigating sympatric distribution of Rhododendron irroratum, examing the variation of floral characters and sequencing the ITS and other chloroplast segements, we find that (1) R. irroratum might be of hybrid origin, with its maternal parent R. delavayi or R. decorum. (2) The ancestral haplotype of R. irroratum might be identical to that of R. decorum, and it is under ongoing introgression from R. delavayi. 1. The natural distribution, Seven distribution sites of R. irroratum in Guizhou and Yunnan province were investigated. The result shows that R. irroratum is sympatric with R. delavayi, R. decorum and R. agastum. R. delavayi is widespread across the above-mentioned seven sites, whereas R. agastum is scarce in DaPingDi, HuaDianBa and HeQing sites. R. irroratum and R. agastum distribute at the higher elevation compared to that of R. decorum, while R. delavayi is of widespread distribution across both regions of R. decorum and R. irroratum.2. Floral variation of R. irroratum among populations, The floral characters remain vary within and among populations except for the stamen number and the petal number. Seven floral characters correlates with each other among populations, of 28 different combinations, 26 reveal significant correlation, and 23 extremely significant correlation. The PCA analysis shows that the first two components account for 52.18% of the total variation. The dendrogram tree is divided into four main parts, roughly representing the respective populations, which is constructed using 22 R. irroratum individuals. 3. Putative Development and the transferability test of SSR makers, Fifteen microsatellite loci were developed and characterized in R. delavayi. The average allele number of these microsatellites was 4 per locus, ranging from 3 to 6. The ranges of expected (HE) and observed (HO) heterozygosities were 0.0365-0.7091 and 0.0263-0.9512, respectively. Seven loci (R-111, R-112, R-147, R-299, R-320, R-335, and R-544) deviated significantly from the HWE (P﹤0.01). No significant linkage disequilibrium was detected between locus pairs except for three locus pairs: R-299 and R-544, R-166 and R-320, R-111 and R-320. Cross-species amplification in R. agastum, R. decorum, and R. irroratum showed that a subset of these markers holds promise for congeneric species study.4. ITS, matK, trnH-psbA and rbcL sequences. R. delavayi has six sites different from that of R. decorum in its ITS region, whereas R. agastum reveals double peaks at the corresponding sites and R. irroratum is identical to that of R. delavayi. The chloroplast segements show that some R. irroratum individuals share the same haplotype with R. delavayi and others share them with R. decorum.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&query1=Hybrid%2BZones&&fq=dc.project.title_filter%3AThrough%5C+investigating%5C+sympatric%5C+distribution%5C+of%5C+Rhododendron%5C+irroratum%2C%5C+examing%5C+the%5C+variation%5C+of%5C+floral%5C+characters%5C+and%5C+sequencing%5C+the%5C+ITS%5C+and%5C+other%5C+chloroplast%5C+segements%2C%5C+we%5C+find%5C+that%5C+%5C%281%5C%29%5C+R.%5C+irroratum%5C+might%5C+be%5C+of%5C+hybrid%5C+origin%2C%5C+with%5C+its%5C+maternal%5C+parent%5C+R.%5C+delavayi%5C+or%5C+R.%5C+decorum.%5C+%5C%282%5C%29%5C+The%5C+ancestral%5C+haplotype%5C+of%5C+R.%5C+irroratum%5C+might%5C+be%5C+identical%5C+to%5C+that%5C+of%5C+R.%5C+decorum%2C%5C+and%5C+it%5C+is%5C+under%5C+ongoing%5C+introgression%5C+from%5C+R.%5C+delavayi.%5C+1.%5C+The%5C+natural%5C+distribution%2C%5C+Seven%5C+distribution%5C+sites%5C+of%5C+R.%5C+irroratum%5C+in%5C+Guizhou%5C+and%5C+Yunnan%5C+province%5C+were%5C+investigated.%5C+The%5C+result%5C+shows%5C+that%5C+R.%5C+irroratum%5C+is%5C+sympatric%5C+with%5C+R.%5C+delavayi%2C%5C+R.%5C+decorum%5C+and%5C+R.%5C+agastum.%5C+R.%5C+delavayi%5C+is%5C+widespread%5C+across%5C+the%5C+above%5C-mentioned%5C+seven%5C+sites%2C%5C+whereas%5C+R.%5C+agastum%5C+is%5C+scarce%5C+in%5C+DaPingDi%2C%5C+HuaDianBa%5C+and%5C+HeQing%5C+sites.%5C+R.%5C+irroratum%5C+and%5C+R.%5C+agastum%5C+distribute%5C+at%5C+the%5C+higher%5C+elevation%5C+compared%5C+to%5C+that%5C+of%5C+R.%5C+decorum%2C%5C+while%5C+R.%5C+delavayi%5C+is%5C+of%5C+widespread%5C+distribution%5C+across%5C+both%5C+regions%5C+of%5C+R.%5C+decorum%5C+and%5C+R.%5C+irroratum.2.%5C+Floral%5C+variation%5C+of%5C+R.%5C+irroratum%5C+among%5C+populations%2C%5C+The%5C+floral%5C+characters%5C+remain%5C+vary%5C+within%5C+and%5C+among%5C+populations%5C+except%5C+for%5C+the%5C+stamen%5C+number%5C+and%5C+the%5C+petal%5C+number.%5C+Seven%5C+floral%5C+characters%5C+correlates%5C+with%5C+each%5C+other%5C+among%5C+populations%2C%5C+of%5C+28%5C+different%5C+combinations%2C%5C+26%5C+reveal%5C+significant%5C+correlation%2C%5C+and%5C+23%5C+extremely%5C+significant%5C+correlation.%5C+The%5C+PCA%5C+analysis%5C+shows%5C+that%5C+the%5C+first%5C+two%5C+components%5C+account%5C+for%5C+52.18%25%5C+of%5C+the%5C+total%5C+variation.%5C+The%5C+dendrogram%5C+tree%5C+is%5C+divided%5C+into%5C+four%5C+main%5C+parts%2C%5C+roughly%5C+representing%5C+the%5C+respective%5C+populations%2C%5C+which%5C+is%5C+constructed%5C+using%5C+22%5C+R.%5C+irroratum%5C+individuals.%5C+3.%5C+Putative%5C+Development%5C+and%5C+the%5C+transferability%5C+test%5C+of%5C+SSR%5C+makers%2C%5C+Fifteen%5C+microsatellite%5C+loci%5C+were%5C+developed%5C+and%5C+characterized%5C+in%5C+R.%5C+delavayi.%5C+The%5C+average%5C+allele%5C+number%5C+of%5C+these%5C+microsatellites%5C+was%5C+4%5C+per%5C+locus%2C%5C+ranging%5C+from%5C+3%5C+to%5C+6.%5C+The%5C+ranges%5C+of%5C+expected%5C+%5C%28HE%5C%29%5C+and%5C+observed%5C+%5C%28HO%5C%29%5C+heterozygosities%5C+were%5C+0.0365%5C-0.7091%5C+and%5C+0.0263%5C-0.9512%2C%5C+respectively.%5C+Seven%5C+loci%5C+%5C%28R%5C-111%2C%5C+R%5C-112%2C%5C+R%5C-147%2C%5C+R%5C-299%2C%5C+R%5C-320%2C%5C+R%5C-335%2C%5C+and%5C+R%5C-544%5C%29%5C+deviated%5C+significantly%5C+from%5C+the%5C+HWE%5C+%5C%28P%EF%B9%A40.01%5C%29.%5C+No%5C+significant%5C+linkage%5C+disequilibrium%5C+was%5C+detected%5C+between%5C+locus%5C+pairs%5C+except%5C+for%5C+three%5C+locus%5C+pairs%5C%3A%5C+R%5C-299%5C+and%5C+R%5C-544%2C%5C+R%5C-166%5C+and%5C+R%5C-320%2C%5C+R%5C-111%5C+and%5C+R%5C-320.%5C+Cross%5C-species%5C+amplification%5C+in%5C+R.%5C+agastum%2C%5C+R.%5C+decorum%2C%5C+and%5C+R.%5C+irroratum%5C+showed%5C+that%5C+a%5C+subset%5C+of%5C+these%5C+markers%5C+holds%5C+promise%5C+for%5C+congeneric%5C+species%5C+study.4.%5C+ITS%2C%5C+matK%2C%5C+trnH%5C-psbA%5C+and%5C+rbcL%5C+sequences.%5C+R.%5C+delavayi%5C+has%5C+six%5C+sites%5C+different%5C+from%5C+that%5C+of%5C+R.%5C+decorum%5C+in%5C+its%5C+ITS%5C+region%2C%5C+whereas%5C+R.%5C+agastum%5C+reveals%5C+double%5C+peaks%5C+at%5C+the%5C+corresponding%5C+sites%5C+and%5C+R.%5C+irroratum%5C+is%5C+identical%5C+to%5C+that%5C+of%5C+R.%5C+delavayi.%5C+The%5C+chloroplast%5C+segements%5C+show%5C+that%5C+some%5C+R.%5C+irroratum%5C+individuals%5C+share%5C+the%5C+same%5C+haplotype%5C+with%5C+R.%5C+delavayi%5C+and%5C+others%5C+share%5C+them%5C+with%5C+R.%5C+decorum."},{"jsname":"lastIndexed","jscount":"2024-07-12"}],"资助项目","dc.project.title_filter")'>
|
|
|
|
|
