|
|
|
|
|
|
|
|
|
|
|
|
资助项目
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.date.issued.year&advanced=false&fq=dc.type_filter%3A%E5%AD%A6%E4%BD%8D%E8%AE%BA%E6%96%87&query1=DECLINE&&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":"The Taxus wallichiana complex represents an old relict conifer lineage that survived through the Tertiary. It is currently distributed in the mountain forests in South and Southwest China south of the Qinling Mountains. In the present study, we explored phylogeography of the complex by using two chloroplast DNA regions, one nuclear ribosomal DNA spacer region and eight microsatellite (SSR) loci. The main conclusions can be summarized as follows:1. Phylogeographic pattern based on chloroplast haplotypes，There were 11 cpDNA haplotypes identified in the T. wallichiana complex The complex showed a high level of genetic diversity and obvious genetic differentiation. The 44 sampled populations showed obvious genetic structure, which could be divided into five groups, namely the Huanan group, the Daba group, the Emei group, the Yunnan group and the Qinling group. There was extremely high genetic differentiation among groups, but not significant within group. The divergence times of the five lineages, estimated using average mutation rates of trnL-trnF, fell in the Pliocene. 2. Phylogeographic patterns based on ITS sequences，These included 38 unique ‘haplotypes’ based on ITS data. Their analysis showed that the T. wallichiana complex possessed a high genetic diversity. These populations could be divided into four groups, namely the Huanan group, the Daba/Emei group, the Yunnan group and the Qinling group. Based on all results, it appears that the major lineages constituting the T. wallichiana complex have arisen before Quaternary glaciation cycles, and may have survived isolated in different refugia. During interglacial periods some lineages appear to have come in contact and hybridizedbut other lineages merged forming populations with mixed haplotypes without signs of hybridization. The present-day phylogeographical distribution pattern of the T. wallichiana complex might thus be the result of repeated expansion / contractions of populations during interglacial / glacial cycles.3. Population genetic analysis using microsatellite (SSR) markers，Eight SSR loci were used for population genetic analysis on the T. wallichiana complex. A lower level of genetic diversity at the population level and high genetic differentiation among population was detected. The results of structure analysis were similar to those on the ITS data, dividing the populations into four groups (lineages). According to the results here, it was deduced that each of the 4 lineages of the T. wallichiana complex may possessed respective glacial refugia, and some lineages (such as the Qinling and Huanan lineage) might have survived in multiple refugia in the Quaternay glaciations. The present distribution pattern of this complex was likely influenced by the uplift of the QTP and Quaternary glaciation.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&fq=dc.type_filter%3A%E5%AD%A6%E4%BD%8D%E8%AE%BA%E6%96%87&query1=DECLINE&&fq=dc.project.title_filter%3AThe%5C+Taxus%5C+wallichiana%5C+complex%5C+represents%5C+an%5C+old%5C+relict%5C+conifer%5C+lineage%5C+that%5C+survived%5C+through%5C+the%5C+Tertiary.%5C+It%5C+is%5C+currently%5C+distributed%5C+in%5C+the%5C+mountain%5C+forests%5C+in%5C+South%5C+and%5C+Southwest%5C+China%5C+south%5C+of%5C+the%5C+Qinling%5C+Mountains.%C2%A0In%5C+the%5C+present%5C+study%2C%5C+we%5C+explored%5C+phylogeography%5C+of%5C+the%5C+complex%5C+by%5C+using%5C+two%5C+chloroplast%5C+DNA%5C+regions%2C%5C+one%5C+nuclear%5C+ribosomal%5C+DNA%5C+spacer%5C+region%5C+and%5C+eight%5C+microsatellite%5C+%5C%28SSR%5C%29%5C+loci.%5C+The%5C+main%5C+conclusions%5C+can%5C+be%5C+summarized%5C+as%5C+follows%5C%3A1.%5C+Phylogeographic%5C+pattern%5C+based%5C+on%5C+chloroplast%5C+haplotypes%EF%BC%8CThere%5C+were%5C+11%5C+cpDNA%5C+haplotypes%5C+identified%5C+in%5C+the%5C+T.%5C+wallichiana%5C+complex%5C+The%5C+complex%5C+showed%5C+a%5C+high%5C+level%5C+of%5C+genetic%5C+diversity%5C+and%5C+obvious%5C+genetic%5C+differentiation.%5C+The%5C+44%5C+sampled%5C+populations%5C+showed%5C+obvious%5C+genetic%5C+structure%2C%5C+which%5C+could%5C+be%5C+divided%5C+into%5C+five%5C+groups%2C%5C+namely%5C+the%5C+Huanan%5C+group%2C%5C+the%5C+Daba%5C+group%2C%5C+the%5C+Emei%5C+group%2C%5C+the%5C+Yunnan%5C+group%5C+and%5C+the%5C+Qinling%5C+group.%5C+There%5C+was%5C+extremely%5C+high%5C+genetic%5C+differentiation%5C+among%5C+groups%2C%5C+but%5C+not%5C+significant%5C+within%5C+group.%5C+The%5C+divergence%5C+times%5C+of%5C+the%5C+five%5C+lineages%2C%5C+estimated%5C+using%5C+average%5C+mutation%5C+rates%5C+of%5C+trnL%5C-trnF%2C%5C+fell%5C+in%5C+the%5C+Pliocene.%C2%A02.%5C+Phylogeographic%5C+patterns%5C+based%5C+on%5C+ITS%5C+sequences%EF%BC%8CThese%5C+included%5C+38%5C+unique%5C+%E2%80%98haplotypes%E2%80%99%5C+based%5C+on%5C+ITS%5C+data.%5C+Their%5C+analysis%5C+showed%5C+that%5C+the%5C+T.%5C+wallichiana%5C+complex%5C+possessed%5C+a%5C+high%5C+genetic%5C+diversity.%C2%A0These%5C+populations%5C+could%5C+be%5C+divided%5C+into%5C+four%5C+groups%2C%5C+namely%5C+the%5C+Huanan%5C+group%2C%5C+the%5C+Daba%5C%2FEmei%5C+group%2C%5C+the%5C+Yunnan%5C+group%5C+and%5C+the%5C+Qinling%5C+group.%5C+Based%5C+on%5C+all%5C+results%2C%5C+it%5C+appears%5C+that%5C+the%5C+major%5C+lineages%5C+constituting%5C+the%5C+T.%5C+wallichiana%5C+complex%5C+have%5C+arisen%5C+before%5C+Quaternary%5C+glaciation%5C+cycles%2C%5C+and%5C+may%5C+have%5C+survived%5C+isolated%5C+in%5C+different%5C+refugia.%5C+During%5C+interglacial%5C+periods%5C+some%5C+lineages%5C+appear%5C+to%5C+have%5C+come%5C+in%5C+contact%5C+and%5C+hybridizedbut%5C+other%5C+lineages%5C+merged%5C+forming%5C+populations%5C+with%5C+mixed%5C+haplotypes%5C+without%5C+signs%5C+of%5C+hybridization.%5C+The%5C+present%5C-day%5C+phylogeographical%5C+distribution%5C+pattern%5C+of%5C+the%5C+T.%5C+wallichiana%5C+complex%5C+might%5C+thus%5C+be%5C+the%5C+result%5C+of%5C+repeated%5C+expansion%5C+%5C%2F%5C+contractions%5C+of%5C+populations%5C+during%5C+interglacial%5C+%5C%2F%5C+glacial%5C+cycles.3.%5C+Population%5C+genetic%5C+analysis%5C+using%5C+microsatellite%5C+%5C%28SSR%5C%29%5C+markers%EF%BC%8CEight%5C+SSR%5C+loci%5C+were%5C+used%5C+for%5C+population%5C+genetic%5C+analysis%5C+on%5C+the%5C+T.%5C+wallichiana%5C+complex.%5C+A%5C+lower%5C+level%5C+of%5C+genetic%5C+diversity%5C+at%5C+the%5C+population%5C+level%5C+and%5C+high%5C+genetic%5C+differentiation%5C+among%5C+population%5C+was%5C+detected.%5C+The%5C+results%5C+of%5C+structure%5C+analysis%5C+were%5C+similar%5C+to%5C+those%5C+on%5C+the%5C+ITS%5C+data%2C%5C+dividing%5C+the%5C+populations%5C+into%5C+four%5C+groups%5C+%5C%28lineages%5C%29.%C2%A0According%5C+to%5C+the%5C+results%5C+here%2C%5C+it%5C+was%5C+deduced%5C+that%5C+each%5C+of%5C+the%5C+4%5C+lineages%5C+of%5C+the%5C+T.%5C+wallichiana%5C+complex%5C+may%5C+possessed%5C+respective%5C+glacial%5C+refugia%2C%5C+and%5C+some%5C+lineages%5C+%5C%28such%5C+as%5C+the%5C+Qinling%5C+and%5C+Huanan%5C+lineage%5C%29%5C+might%5C+have%5C+survived%5C+in%5C+multiple%5C+refugia%5C+in%5C+the%5C+Quaternay%5C+glaciations.%5C+The%5C+present%5C+distribution%5C+pattern%5C+of%5C+this%5C+complex%5C+was%5C+likely%5C+influenced%5C+by%5C+the%5C+uplift%5C+of%5C+the%5C+QTP%5C+and%5C+Quaternary%5C+glaciation."},{"jsname":"The genus Quercus consists of subgenera Quercus and Cyclobalanopsis and has approximately 531 species, making this the largest and most widely distributed genus within the Fagaceae family, occurring throughout temperate and subtropical montane areas of the Northern Hemisphere. The occurrence of recalcitrant (desiccation-sensitive) seeded plants is common in the genus Quercus, making it one of the key genera for understanding the physiology and the ecology of recalcitrant seeds. Due to habitat loss and poor regeneration, some populations of the genus Quercus are now declining. Moreover, the limited availability of good-quality seed may lead to its natural regeneration problems. To understand the cause of the population decline and to conserve iteffectively, knowledge on the seed/fruit biology of Quercus is necessary. Despite this, the seed/fruit biology of the Asian Quercus species is largely overlooked and the seed/fruit biology of Quercus subgenus Cyclobalanopsis,which is predominately distributed across tropical and subtropical Asia, is less well documented. To provide new data on the fruit biology of subgenus Cyclobalanopsis and to understand the fruit physiology and ecology of the genus Quercus comprehensively for a conservation aim, the germination and desiccation response of 11 species of subgenus Cyclobalanopsis (from S and SW China) and 11 species of subgenus Quercus (from both SW China and Europe) were investigated. The anatomic characteristics of the fruit coats was analysed on 9 of these species and the oil contents were quantified from 18 of these species. In addition, a study was carried out over 4 years on the fruit production of Q. schottkyana (subgenus Cyclobalanopsis) to fill the gap in knowledge. The data demonstrate that: 1. All 22 species of subgenus Cyclobalanopsis and subgenus Quercus had desiccation-sensitive (recalcitrant) fruits. For these 22 species which had fruit dry masses spanning 0.57 to 6.41 g and seed coat ratios spanning 0.15 to 0.48, there were wide differences in drying rates (0.26-4.10 %d-1). These differences were independent of fruit mass and seed coat ratio, but were related to the morphology of the fruit coat.2. The scar, composing 4% to 37% (surface area) of the whole fruit coat, was found to be the main water passage for most species. Water transferred directly and quickly through the scar. From the scar through to the pericarp and ending at the apex, there was a longitudinal passage of water flow. The anatomic characteristics of the fruit coats controlled the water flux, which furthermore introduced the wide differences in drying rates between the Quercus species.3. In comparison to species of Quercus subgenus Quercus, fruits in subgenus Cyclobalanopsis germinated faster and most had maximum germination at the highest temperature of 25°C. At lower temperatures (15°C, 20°C), germination of subgenus Cyclobalanopsis was slower and the germination percentage of most species was decreased, but germination of species in subgenus Quercus was not affected at these low temperatures. The thermal requirements for the germination of these two subgenera suggested an adaptability of these fruits to their habitats.4. Fruit oil content of subgenus Cyclobalanopsis (0.70% to 3.77%) was significantly lower than that of subgenus Quercus (1.48 to 18.01%) and across the 18 species studied, moisture content of the storage tissue (cotyledons) was negatively related to fruit oil content. These data were combined with that from the literature, resulting in a total of 57 species, and mapped against the current phylogeny for Quercus to reveal the highest fruit oil contents associated with sect. Lobatae. 5. The fruit production of Q. schottkyana varied markedly between years. Each square meter of Q. schottkyana pure forest produced 245-854 fruits but 14%-48% of them were infected by weevils (Curculio sp.). The annual production of Q. schottkyana was most likely affected by the average monthly rainfall during May and June, but the time of fruit dispersal was related to the rainfall of September and November. The infestation rates of weevils were density-dependent on the fruit production of Q. schottkyana that furthermore regulated the populations of these two species.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&fq=dc.type_filter%3A%E5%AD%A6%E4%BD%8D%E8%AE%BA%E6%96%87&query1=DECLINE&&fq=dc.project.title_filter%3AThe%5C+genus%5C+Quercus%5C+consists%5C+of%5C+subgenera%5C+Quercus%5C+and%5C+Cyclobalanopsis%5C+and%5C+has%5C+approximately%5C+531%5C+species%2C%5C+making%5C+this%5C+the%5C+largest%5C+and%5C+most%5C+widely%5C+distributed%5C+genus%5C+within%5C+the%5C+Fagaceae%5C+family%2C%5C+occurring%5C+throughout%5C+temperate%5C+and%5C+subtropical%5C+montane%5C+areas%5C+of%5C+the%5C+Northern%5C+Hemisphere.%5C+The%5C+occurrence%5C+of%5C+recalcitrant%5C+%5C%28desiccation%5C-sensitive%5C%29%5C+seeded%5C+plants%5C+is%5C+common%5C+in%5C+the%5C+genus%5C+Quercus%2C%5C+making%5C+it%5C+one%5C+of%5C+the%5C+key%5C+genera%5C+for%5C+understanding%5C+the%5C+physiology%5C+and%5C+the%5C+ecology%5C+of%5C+recalcitrant%5C+seeds.%5C+Due%5C+to%5C+habitat%5C+loss%5C+and%5C+poor%5C+regeneration%2C%5C+some%5C+populations%5C+of%5C+the%5C+genus%5C+Quercus%5C+are%5C+now%5C+declining.%5C+Moreover%2C%5C+the%5C+limited%5C+availability%5C+of%5C+good%5C-quality%5C+seed%5C+may%5C+lead%5C+to%5C+its%5C+natural%5C+regeneration%5C+problems.%5C+To%5C+understand%5C+the%5C+cause%5C+of%5C+the%5C+population%5C+decline%5C+and%5C+to%5C+conserve%5C+iteffectively%2C%5C+knowledge%5C+on%5C+the%5C+seed%5C%2Ffruit%5C+biology%5C+of%5C+Quercus%5C+is%5C+necessary.%5C+Despite%5C+this%2C%5C+the%5C+seed%5C%2Ffruit%5C+biology%5C+of%5C+the%5C+Asian%5C+Quercus%5C+species%5C+is%5C+largely%5C+overlooked%5C+and%5C+the%5C+seed%5C%2Ffruit%5C+biology%5C+of%5C+Quercus%5C+subgenus%5C+Cyclobalanopsis%2Cwhich%5C+is%5C+predominately%5C+distributed%5C+across%5C+tropical%5C+and%5C+subtropical%5C+Asia%2C%5C+is%5C+less%5C+well%5C+documented.%5C+To%5C+provide%5C+new%5C+data%5C+on%5C+the%5C+fruit%5C+biology%5C+of%5C+subgenus%5C+Cyclobalanopsis%5C+and%5C+to%5C+understand%5C+the%5C+fruit%5C+physiology%5C+and%5C+ecology%5C+of%5C+the%5C+genus%5C+Quercus%5C+comprehensively%5C+for%5C+a%5C+conservation%5C+aim%2C%5C+the%5C+germination%5C+and%5C+desiccation%5C+response%5C+of%5C+11%5C+species%5C+of%5C+subgenus%5C+Cyclobalanopsis%5C+%5C%28from%5C+S%5C+and%5C+SW%5C+China%5C%29%5C+and%5C+11%5C+species%5C+of%5C+subgenus%5C+Quercus%5C+%5C%28from%5C+both%5C+SW%5C+China%5C+and%5C+Europe%5C%29%5C+were%5C+investigated.%5C+The%5C+anatomic%5C+characteristics%5C+of%5C+the%5C+fruit%5C+coats%5C+was%5C+analysed%5C+on%5C+9%5C+of%5C+these%5C+species%5C+and%5C+the%5C+oil%5C+contents%5C+were%5C+quantified%5C+from%5C+18%5C+of%5C+these%5C+species.%5C+In%5C+addition%2C%5C+a%5C+study%5C+was%5C+carried%5C+out%5C+over%5C+4%5C+years%5C+on%5C+the%5C+fruit%5C+production%5C+of%5C+Q.%5C+schottkyana%5C+%5C%28subgenus%5C+Cyclobalanopsis%5C%29%5C+to%5C+fill%5C+the%5C+gap%5C+in%5C+knowledge.%5C+The%5C+data%5C+demonstrate%5C+that%5C%3A%5C+1.%5C+All%5C+22%5C+species%5C+of%5C+subgenus%5C+Cyclobalanopsis%5C+and%5C+subgenus%5C+Quercus%5C+had%5C+desiccation%5C-sensitive%5C+%5C%28recalcitrant%5C%29%5C+fruits.%5C+For%5C+these%5C+22%5C+species%5C+which%5C+had%5C+fruit%5C+dry%5C+masses%5C+spanning%5C+0.57%5C+to%5C+6.41%5C+g%5C+and%5C+seed%5C+coat%5C+ratios%5C+spanning%5C+0.15%5C+to%5C+0.48%2C%5C+there%5C+were%5C+wide%5C+differences%5C+in%5C+drying%5C+rates%5C+%5C%280.26%5C-4.10%5C+%25d%5C-1%5C%29.%5C+These%5C+differences%5C+were%5C+independent%5C+of%5C+fruit%5C+mass%5C+and%5C+seed%5C+coat%5C+ratio%2C%5C+but%5C+were%5C+related%5C+to%5C+the%5C+morphology%5C+of%5C+the%5C+fruit%5C+coat.2.%5C+%5C+The%5C+scar%2C%5C+composing%5C+4%25%5C+to%5C+37%25%5C+%5C%28surface%5C+area%5C%29%5C+of%5C+the%5C+whole%5C+fruit%5C+coat%2C%5C+was%5C+found%5C+to%5C+be%5C+the%5C+main%5C+water%5C+passage%5C+for%5C+most%5C+species.%5C+Water%5C+transferred%5C+directly%5C+and%5C+quickly%5C+through%5C+the%5C+scar.%5C+From%5C+the%5C+scar%5C+through%5C+to%5C+the%5C+pericarp%5C+and%5C+ending%5C+at%5C+the%5C+apex%2C%5C+there%5C+was%5C+a%5C+longitudinal%5C+passage%5C+of%5C+water%5C+flow.%5C+The%5C+anatomic%5C+characteristics%5C+of%5C+the%5C+fruit%5C+coats%5C+controlled%5C+the%5C+water%5C+flux%2C%5C+which%5C+furthermore%5C+introduced%5C+the%5C+wide%5C+differences%5C+in%5C+drying%5C+rates%5C+between%5C+the%5C+Quercus%5C+species.3.%5C+In%5C+comparison%5C+to%5C+species%5C+of%5C+Quercus%5C+subgenus%5C+Quercus%2C%5C+fruits%5C+in%5C+subgenus%5C+Cyclobalanopsis%5C+germinated%5C+faster%5C+and%5C+most%5C+had%5C+maximum%5C+germination%5C+at%5C+the%5C+highest%5C+temperature%5C+of%5C+25%C2%B0C.%5C+At%5C+lower%5C+temperatures%5C+%5C%2815%C2%B0C%2C%5C+20%C2%B0C%5C%29%2C%5C+germination%5C+of%5C+subgenus%5C+Cyclobalanopsis%5C+was%5C+slower%5C+and%5C+the%5C+germination%5C+percentage%5C+of%5C+most%5C+species%5C+was%5C+decreased%2C%5C+but%5C+germination%5C+of%5C+species%5C+in%5C+subgenus%5C+Quercus%5C+was%5C+not%5C+affected%5C+at%5C+these%5C+low%5C+temperatures.%5C+The%5C+thermal%5C+requirements%5C+for%5C+the%5C+germination%5C+of%5C+these%5C+two%5C+subgenera%5C+suggested%5C+an%5C+adaptability%5C+of%5C+these%5C+fruits%5C+to%5C+their%5C+habitats.4.%5C+%5C+Fruit%5C+oil%5C+content%5C+of%5C+subgenus%5C+Cyclobalanopsis%5C+%5C%280.70%25%5C+to%5C+3.77%25%5C%29%5C+was%5C+significantly%5C+lower%5C+than%5C+that%5C+of%5C+subgenus%5C+Quercus%5C+%5C%281.48%5C+to%5C+18.01%25%5C%29%5C+and%5C+across%5C+the%5C+18%5C+species%5C+studied%2C%5C+moisture%5C+content%5C+of%5C+the%5C+storage%5C+tissue%5C+%5C%28cotyledons%5C%29%5C+was%5C+negatively%5C+related%5C+to%5C+fruit%5C+oil%5C+content.%5C+These%5C+data%5C+were%5C+combined%5C+with%5C+that%5C+from%5C+the%5C+literature%2C%5C+resulting%5C+in%5C+a%5C+total%5C+of%5C+57%5C+species%2C%5C+and%5C+mapped%5C+against%5C+the%5C+current%5C+phylogeny%5C+for%5C+Quercus%5C+to%5C+reveal%5C+the%5C+highest%5C+fruit%5C+oil%5C+contents%5C+associated%5C+with%5C+sect.%5C+Lobatae.%5C+5.%5C+%5C+The%5C+fruit%5C+production%5C+of%5C+Q.%5C+schottkyana%5C+varied%5C+markedly%5C+between%5C+years.%5C+Each%5C+square%5C+meter%5C+of%5C+Q.%5C+schottkyana%5C+pure%5C+forest%5C+produced%5C+245%5C-854%5C+fruits%5C+but%5C+14%25%5C-48%25%5C+of%5C+them%5C+were%5C+infected%5C+by%5C+weevils%5C+%5C%28Curculio%5C+sp.%5C%29.%5C+The%5C+annual%5C+production%5C+of%5C+Q.%5C+schottkyana%5C+was%5C+most%5C+likely%5C+affected%5C+by%5C+the%5C+average%5C+monthly%5C+rainfall%5C+during%5C+May%5C+and%5C+June%2C%5C+but%5C+the%5C+time%5C+of%5C+fruit%5C+dispersal%5C+was%5C+related%5C+to%5C+the%5C+rainfall%5C+of%5C+September%5C+and%5C+November.%5C+The%5C+infestation%5C+rates%5C+of%5C+weevils%5C+were%5C+density%5C-dependent%5C+on%5C+the%5C+fruit%5C+production%5C+of%5C+Q.%5C+schottkyana%5C+that%5C+furthermore%5C+regulated%5C+the%5C+populations%5C+of%5C+these%5C+two%5C+species."},{"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.date.issued.year&advanced=false&fq=dc.type_filter%3A%E5%AD%A6%E4%BD%8D%E8%AE%BA%E6%96%87&query1=DECLINE&&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":"Tibetan Plateau is one of the most sensitive areas to global climate change. The response of alpine ecosystem to climate change becomes a hot topic of scientific research. Plant phenology is best indicator of climate change. It will be meaningful to look at the response of alpine ecosystem to climate change from the plant phenology point of view. However, phenology research is still very weak on the Tibetan Plateau, and the ground observations are also very limited. Therefore, study on the growing season change and relation with temperature and precipitation will be scientifically and practically meaningful.In this study, we studied the interannual change of NDVI, temperature and precipitation and their correlation. Then the growing season on the Tibetan Plateau was simulated using both the slope method and NDVI ratio method. By comparing the results with ground observation, the NDVI ratio method with certain threshold was selected. Growing season from 1982-2006 was simulated with the selected method and then the spatial and temporal distribution of growing season was analyzed. Finally, we used multi-regression to derive the relation between growing season, temperature and precipitation. Some main conclusions were drawn from this study. NDVI ratio method performs better in simulating the growing season than slope method. The final thresholds selected for simulating the start and end dates of growing season are 0.2 and 0.6, respectively. Both the mean NDVI in May and June and beginning dates of growing season of meadow and steppe shows non-linear trend from 1982 to 2006. However, the beginning dates of growing season of meadow and steppe before 2000 display significant advance trend(0.48 d yr-1 and 0.62d yr-1,respectively), but delay after 2000；the end dats of meadow shows no significant trend during 1982 and 2000,but trend of the end dats of steppe is significant(0.52 d yr-1)；the lengths of growing season of meadow and steppe become longer before 2000(0.49d yr-1 and 0.55 d yr-1,respectively), then become shorter afterwards. Relation between temperature and precipitation with beginning dates of growing season is more significant than with end dates. The significantly rising temperature in winter delay the beginning dates of growing season because of the reduction of chilling requirement. Increase of spring temperature and precipitation promotes early beginning dates of growing season. The end dates of growing season are early due to the increase of temperature in July and August, but are late when temperature in September and precipitation from May to September increases.Finally, we figure out the shortcoming of the study and recommend possible way to solve the problem and more detailed future work is required.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&fq=dc.type_filter%3A%E5%AD%A6%E4%BD%8D%E8%AE%BA%E6%96%87&query1=DECLINE&&fq=dc.project.title_filter%3ATibetan%5C+Plateau%5C+is%5C+one%5C+of%5C+the%5C+most%5C+sensitive%5C+areas%5C+to%5C+global%5C+climate%5C+change.%5C+The%5C+response%5C+of%5C+alpine%5C+ecosystem%5C+to%5C+climate%5C+change%5C+becomes%5C+a%5C+hot%5C+topic%5C+of%5C+scientific%5C+research.%5C+Plant%5C+phenology%5C+is%5C+best%5C+indicator%5C+of%5C+climate%5C+change.%5C+It%5C+will%5C+be%5C+meaningful%5C+to%5C+look%5C+at%5C+the%5C+response%5C+of%5C+alpine%5C+ecosystem%5C+to%5C+climate%5C+change%5C+from%5C+the%5C+plant%5C+phenology%5C+point%5C+of%5C+view.%5C+However%2C%5C+phenology%5C+research%5C+is%5C+still%5C+very%5C+weak%5C+on%5C+the%5C+Tibetan%5C+Plateau%2C%5C+and%5C+the%5C+ground%5C+observations%5C+are%5C+also%5C+very%5C+limited.%5C+Therefore%2C%5C+study%5C+on%5C+the%5C+growing%5C+season%5C+change%5C+and%5C+relation%5C+with%5C+temperature%5C+and%5C+precipitation%5C+will%5C+be%5C+scientifically%5C+and%5C+practically%5C+meaningful.In%5C+this%5C+study%2C%5C+we%5C+studied%5C+the%5C+interannual%5C+change%5C+of%5C+NDVI%2C%5C+temperature%5C+and%5C+precipitation%5C+and%5C+their%5C+correlation.%5C+Then%5C+the%5C+growing%5C+season%5C+on%5C+the%5C+Tibetan%5C+Plateau%5C+was%5C+simulated%5C+using%5C+both%5C+the%5C+slope%5C+method%5C+and%5C+NDVI%5C+ratio%5C+method.%5C+By%5C+comparing%5C+the%5C+results%5C+with%5C+ground%5C+observation%2C%5C+the%5C+NDVI%5C+ratio%5C+method%5C+with%5C+certain%5C+threshold%5C+was%5C+selected.%5C+Growing%5C+season%5C+from%5C+1982%5C-2006%5C+was%5C+simulated%5C+with%5C+the%5C+selected%5C+method%5C+and%5C+then%5C+the%5C+spatial%5C+and%5C+temporal%5C+distribution%5C+of%5C+growing%5C+season%5C+was%5C+analyzed.%5C+Finally%2C%5C+we%5C+used%5C+multi%5C-regression%5C+to%5C+derive%5C+the%5C+relation%5C+between%5C+growing%5C+season%2C%5C+temperature%5C+and%5C+precipitation.%5C+Some%5C+main%5C+conclusions%5C+were%5C+drawn%5C+from%5C+this%5C+study.%5C+NDVI%5C+ratio%5C+method%5C+performs%5C+better%5C+in%5C+simulating%5C+the%5C+growing%5C+season%5C+than%5C+slope%5C+method.%5C+The%5C+final%5C+thresholds%5C+selected%5C+for%5C+simulating%5C+the%5C+start%5C+and%5C+end%5C+dates%5C+of%5C+growing%5C+season%5C+are%5C+0.2%5C+and%5C+0.6%2C%5C+respectively.%5C+Both%5C+the%5C+mean%5C+NDVI%5C+in%5C+May%5C+and%5C+June%5C+and%5C+beginning%5C+dates%5C+of%5C+growing%5C+season%5C+of%5C+meadow%5C+and%5C+steppe%5C+shows%5C+non%5C-linear%5C+trend%5C+from%5C+1982%5C+to%5C+2006.%5C+However%2C%5C+the%5C+beginning%5C+dates%5C+of%5C+growing%5C+season%5C+of%5C+meadow%5C+and%5C+steppe%5C+before%5C+2000%5C+display%5C+significant%5C+advance%5C+trend%5C%280.48%5C+d%5C+yr%5C-1%5C+and%5C+0.62d%5C+yr%5C-1%2Crespectively%5C%29%2C%5C+but%5C+delay%5C+after%5C+2000%EF%BC%9Bthe%5C+end%5C+dats%5C+of%5C+meadow%5C+shows%5C+no%5C+significant%5C+trend%5C+during%5C+1982%5C+and%5C+2000%2Cbut%5C+trend%5C+of%5C+the%5C+end%5C+dats%5C+of%5C+steppe%5C+is%5C+significant%5C%280.52%5C+d%5C+yr%5C-1%5C%29%EF%BC%9Bthe%5C+lengths%5C+of%5C+growing%5C+season%5C+of%5C+meadow%5C+and%5C+steppe%5C+become%5C+longer%5C+before%5C+2000%5C%280.49d%5C+yr%5C-1%5C+and%5C+0.55%5C+d%5C+yr%5C-1%2Crespectively%5C%29%2C%5C+then%5C+become%5C+shorter%5C+afterwards.%5C+Relation%5C+between%5C+temperature%5C+and%5C+precipitation%5C+with%5C+beginning%5C+dates%5C+of%5C+growing%5C+season%5C+is%5C+more%5C+significant%5C+than%5C+with%5C+end%5C+dates.%5C+The%5C+significantly%5C+rising%5C+temperature%5C+in%5C+winter%5C+delay%5C+the%5C+beginning%5C+dates%5C+of%5C+growing%5C+season%5C+because%5C+of%5C+the%5C+reduction%5C+of%5C+chilling%5C+requirement.%5C+Increase%5C+of%5C+spring%5C+temperature%5C+and%5C+precipitation%5C+promotes%5C+early%5C+beginning%5C+dates%5C+of%5C+growing%5C+season.%5C+The%5C+end%5C+dates%5C+of%5C+growing%5C+season%5C+are%5C+early%5C+due%5C+to%5C+the%5C+increase%5C+of%5C+temperature%5C+in%5C+July%5C+and%5C+August%2C%5C+but%5C+are%5C+late%5C+when%5C+temperature%5C+in%5C+September%5C+and%5C+precipitation%5C+from%5C+May%5C+to%5C+September%5C+increases.Finally%2C%5C+we%5C+figure%5C+out%5C+the%5C+shortcoming%5C+of%5C+the%5C+study%5C+and%5C+recommend%5C+possible%5C+way%5C+to%5C+solve%5C+the%5C+problem%5C+and%5C+more%5C+detailed%5C+future%5C+work%5C+is%5C+required."},{"jsname":"Until now, little data about the plant reproductive characters and ecological adaptation have been documented in the species-rich Sino-Himalaya region. Anemone rivularis (Ranunculaceae), mainly occurs in this area, and is of particular interest for its unique flower heliotropic movement and sex allocation strategy. In this study, we investigated the reproductive biology and adaptation mechanism of A. rivularis on the Yulong Snow Mountain Lijiang, northwestern Yunnan. The main results were summarized as follows: 1 Reproductive biology, The mating system, flowering phenology, floral morphology and pollination efficiency were examined in Anemone rivularis. This species is a perennial plant with hermaphroditic flowers, and its inflorescence is an acropetal cyme with protogynous flowers. In contrast to some self-incompatible species reported in Anemone, our results proved that A. rivularis was self-compatible. The seed set under natural pollination was more than 70%, indicating that there was no pollen limitation. Meanwhile, the seed set of artificial-cross-pollinated flowers was significantly higher than that of artificial-self-pollinated flowers, suggesting that the mixed mating system of A. rivularis was based on cross-pollination, and the results also supported a favor of outcrossing reproductive strategy for perennial herbs as some previous reports. Clearly, the reproductive strategy of A. rivularis prefer to cross-pollination in the alpine Sino-Himalayan region, in order to improve the reproductive fitness. 2 Flower heliotropism, The flower heliotropic movement mechanism, influences and adaptive significance were investigated in Anemone rivularis. The results indicated that under natural conditions, a treatment of pistils and stamens removal, flowers of A. rivularis retained accurately sun-tracking behavior through daytime, and the petals were found to close in the evening; but flowers would lose heliotropic movement if tepals were removed, with peduncles keeping a vertical orientation. This indicated that the tepals were crucial for heliotropic behavior. The flower heliotropism of A. rivularis was sensitive to blue light frequencies rather than red frequencies, suggesting that the light signal must be received by tepals, which driving the peduncles to bend due to differential cell elongation along the two sides of peduncle. Furthermore, there was a close relationship between diurnal heliotropic movements and temperature of flower interior in A. rivularis. Flowers with tepals could provide a relatively narrow range of temperatures, in comparison with flowers lacking tepals, in order to maintain reproductive organs in functional floral temperature range. Our study demonstrated that both the development of pistils and stamens and the visiting of insects could benefit from flower heliotropism in A. rivularis.3 Sex allocation, Floral traits, male and female functions, reproductive fitness, and sex allocation hypotheses were assessed in intra-inflorescence of Anemone rivularis. Though the inflorescence showed an acropetal flower-opening sequence as well as in many flowering species (early flowers are proximal and late flowers are distal), it engaged different sex allocation strategy. Our observations documented that the late-opening flowers of each inflorescence produce significantly more ovules and fewer pollen grains compared to early-opening flowers, and the pollen:ovule ratio (P:O) declined obviously from primary flower position to tertiary flower position, suggesting that later flowers would tend to favor female-bias investment. The nature-pollinating seed set among flower positions was constant, and there was no resource trade-off between flower size and sexual organs in this species, and the first-removal treatment did not lead to a significant increase in seed set of flowers in the later position. Thus, early-opening flower may not represent a significant competitor for resources with late-opening flowers on the same inflorescence, suggesting that the pattern of floral design and floral display may be determined prior to flowering and is inalterable by resources during flowering. So the female-biased allocation of distal flowers in A. rivularis may be resulted from the the selection by variation in the mating environment.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.date.issued.year&advanced=false&fq=dc.type_filter%3A%E5%AD%A6%E4%BD%8D%E8%AE%BA%E6%96%87&query1=DECLINE&&fq=dc.project.title_filter%3AUntil%5C+now%2C%5C+little%5C+data%5C+about%5C+the%5C+plant%5C+reproductive%5C+characters%5C+and%5C+ecological%5C+adaptation%5C+have%5C+been%5C+documented%5C+in%5C+the%5C+species%5C-rich%5C+Sino%5C-Himalaya%5C+region.%5C+Anemone%5C+rivularis%5C+%5C%28Ranunculaceae%5C%29%2C%5C+mainly%5C+occurs%5C+in%5C+this%5C+area%2C%5C+and%5C+is%5C+of%5C+particular%5C+interest%5C+for%5C+its%5C+unique%5C+flower%5C+heliotropic%5C+movement%5C+and%5C+sex%5C+allocation%5C+strategy.%5C+In%5C+this%5C+study%2C%5C+we%5C+investigated%5C+the%5C+reproductive%5C+biology%5C+and%5C+adaptation%5C+mechanism%5C+of%5C+A.%5C+rivularis%5C+on%5C+the%5C+Yulong%5C+Snow%5C+Mountain%5C+Lijiang%2C%5C+northwestern%5C+Yunnan.%5C+The%5C+main%5C+results%5C+were%5C+summarized%5C+as%5C+follows%5C%3A%5C+1%5C+Reproductive%5C+biology%2C%5C+The%5C+mating%5C+system%2C%5C+flowering%5C+phenology%2C%5C+floral%5C+morphology%5C+and%5C+pollination%5C+efficiency%5C+were%5C+examined%5C+in%5C+Anemone%5C+rivularis.%5C+This%5C+species%5C+is%5C+a%5C+perennial%5C+plant%5C+with%5C+hermaphroditic%5C+flowers%2C%5C+and%5C+its%5C+inflorescence%5C+is%5C+an%5C+acropetal%5C+cyme%5C+with%5C+protogynous%5C+flowers.%5C+In%5C+contrast%5C+to%5C+some%5C+self%5C-incompatible%5C+species%5C+reported%5C+in%5C+Anemone%2C%5C+our%5C+results%5C+proved%5C+that%5C+A.%5C+rivularis%5C+was%5C+self%5C-compatible.%5C+The%5C+seed%5C+set%5C+under%5C+natural%5C+pollination%5C+was%5C+more%5C+than%5C+70%25%2C%5C+indicating%5C+that%5C+there%5C+was%5C+no%5C+pollen%5C+limitation.%5C+Meanwhile%2C%5C+the%5C+seed%5C+set%5C+of%5C+artificial%5C-cross%5C-pollinated%5C+flowers%5C+was%5C+significantly%5C+higher%5C+than%5C+that%5C+of%5C+artificial%5C-self%5C-pollinated%5C+flowers%2C%5C+suggesting%5C+that%5C+the%5C+mixed%5C+mating%5C+system%5C+of%5C+A.%5C+rivularis%5C+was%5C+based%5C+on%5C+cross%5C-pollination%2C%5C+and%5C+the%5C+results%5C+also%5C+supported%5C+a%5C+favor%5C+of%5C+outcrossing%5C+reproductive%5C+strategy%5C+for%5C+perennial%5C+herbs%5C+as%5C+some%5C+previous%5C+reports.%5C+Clearly%2C%5C+the%5C+reproductive%5C+strategy%5C+of%5C+A.%5C+rivularis%5C+prefer%5C+to%5C+cross%5C-pollination%5C+in%5C+the%5C+alpine%5C+Sino%5C-Himalayan%5C+region%2C%5C+in%5C+order%5C+to%5C+improve%5C+the%5C+reproductive%5C+fitness.%5C+2%5C+Flower%5C+heliotropism%2C%5C+The%5C+flower%5C+heliotropic%5C+movement%5C+mechanism%2C%5C+influences%5C+and%5C+adaptive%5C+significance%5C+were%5C+investigated%5C+in%5C+Anemone%5C+rivularis.%5C+The%5C+results%5C+indicated%5C+that%5C+under%5C+natural%5C+conditions%2C%5C+a%5C+treatment%5C+of%5C+pistils%5C+and%5C+stamens%5C+removal%2C%5C+flowers%5C+of%5C+A.%5C+rivularis%5C+retained%5C+accurately%5C+sun%5C-tracking%5C+behavior%5C+through%5C+daytime%2C%5C+and%5C+the%5C+petals%5C+were%5C+found%5C+to%5C+close%5C+in%5C+the%5C+evening%5C%3B%5C+but%5C+flowers%5C+would%5C+lose%5C+heliotropic%5C+movement%5C+if%5C+tepals%5C+were%5C+removed%2C%5C+with%5C+peduncles%5C+keeping%5C+a%5C+vertical%5C+orientation.%5C+This%5C+indicated%5C+that%5C+the%5C+tepals%5C+were%5C+crucial%5C+for%5C+heliotropic%5C+behavior.%5C+The%5C+flower%5C+heliotropism%5C+of%5C+A.%5C+rivularis%5C+was%5C+sensitive%5C+to%5C+blue%5C+light%5C+frequencies%5C+rather%5C+than%5C+red%5C+frequencies%2C%5C+suggesting%5C+that%5C+the%5C+light%5C+signal%5C+must%5C+be%5C+received%5C+by%5C+tepals%2C%5C+which%5C+driving%5C+the%5C+peduncles%5C+to%5C+bend%5C+due%5C+to%5C+differential%5C+cell%5C+elongation%5C+along%5C+the%5C+two%5C+sides%5C+of%5C+peduncle.%5C+Furthermore%2C%5C+there%5C+was%5C+a%5C+close%5C+relationship%5C+between%5C+diurnal%5C+heliotropic%5C+movements%5C+and%5C+temperature%5C+of%5C+flower%5C+interior%5C+in%5C+A.%5C+rivularis.%5C+Flowers%5C+with%5C+tepals%5C+could%5C+provide%5C+a%5C+relatively%5C+narrow%5C+range%5C+of%5C+temperatures%2C%5C+in%5C+comparison%5C+with%5C+flowers%5C+lacking%5C+tepals%2C%5C+in%5C+order%5C+to%5C+maintain%5C+reproductive%5C+organs%5C+in%5C+functional%5C+floral%5C+temperature%5C+range.%5C+Our%5C+study%5C+demonstrated%5C+that%5C+both%5C+the%5C+development%5C+of%5C+pistils%5C+and%5C+stamens%5C+and%5C+the%5C+visiting%5C+of%5C+insects%5C+could%5C+benefit%5C+from%5C+flower%5C+heliotropism%5C+in%5C+A.%5C+rivularis.3%5C+Sex%5C+allocation%2C%5C+Floral%5C+traits%2C%5C+male%5C+and%5C+female%5C+functions%2C%5C+reproductive%5C+fitness%2C%5C+and%5C+sex%5C+allocation%5C+hypotheses%5C+were%5C+assessed%5C+in%5C+intra%5C-inflorescence%5C+of%5C+Anemone%5C+rivularis.%5C+Though%5C+the%5C+inflorescence%5C+showed%5C+an%5C+acropetal%5C+flower%5C-opening%5C+sequence%5C+as%5C+well%5C+as%5C+in%5C+many%5C+flowering%5C+species%5C+%5C%28early%5C+flowers%5C+are%5C+proximal%5C+and%5C+late%5C+flowers%5C+are%5C+distal%5C%29%2C%5C+it%5C+engaged%5C+different%5C+sex%5C+allocation%5C+strategy.%5C+Our%5C+observations%5C+documented%5C+that%5C+the%5C+late%5C-opening%5C+flowers%5C+of%5C+each%5C+inflorescence%5C+produce%5C+significantly%5C+more%5C+ovules%5C+and%5C+fewer%5C+pollen%5C+grains%5C+compared%5C+to%5C+early%5C-opening%5C+flowers%2C%5C+and%5C+the%5C+pollen%5C%3Aovule%5C+ratio%5C+%5C%28P%5C%3AO%5C%29%5C+declined%5C+obviously%5C+from%5C+primary%5C+flower%5C+position%5C+to%5C+tertiary%5C+flower%5C+position%2C%5C+suggesting%5C+that%5C+later%5C+flowers%5C+would%5C+tend%5C+to%5C+favor%5C+female%5C-bias%5C+investment.%5C+The%5C+nature%5C-pollinating%5C+seed%5C+set%5C+among%5C+flower%5C+positions%5C+was%5C+constant%2C%5C+and%5C+there%5C+was%5C+no%5C+resource%5C+trade%5C-off%5C+between%5C+flower%5C+size%5C+and%5C+sexual%5C+organs%5C+in%5C+this%5C+species%2C%5C+and%5C+the%5C+first%5C-removal%5C+treatment%5C+did%5C+not%5C+lead%5C+to%5C+a%5C+significant%5C+increase%5C+in%5C+seed%5C+set%5C+of%5C+flowers%5C+in%5C+the%5C+later%5C+position.%5C+Thus%2C%5C+early%5C-opening%5C+flower%5C+may%5C+not%5C+represent%5C+a%5C+significant%5C+competitor%5C+for%5C+resources%5C+with%5C+late%5C-opening%5C+flowers%5C+on%5C+the%5C+same%5C+inflorescence%2C%5C+suggesting%5C+that%5C+the%5C+pattern%5C+of%5C+floral%5C+design%5C+and%5C+floral%5C+display%5C+may%5C+be%5C+determined%5C+prior%5C+to%5C+flowering%5C+and%5C+is%5C+inalterable%5C+by%5C+resources%5C+during%5C+flowering.%5C+So%5C+the%5C+female%5C-biased%5C+allocation%5C+of%5C+distal%5C+flowers%5C+in%5C+A.%5C+rivularis%5C+may%5C+be%5C+resulted%5C+from%5C+the%5C+the%5C+selection%5C+by%5C+variation%5C+in%5C+the%5C+mating%5C+environment."},{"jsname":"lastIndexed","jscount":"2024-08-30"}],"资助项目","dc.project.title_filter")'>
|
|
|
|
|
