|
|
|
|
|
|
|
|
|
|
|
|
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.project.fundingorganization_filter&advanced=false&fq=dc.language.iso_filter%3A%E4%B8%AD%E6%96%87&query1=Genera&&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":"Subtrib. Saccharinae Kuntze belongs to the tribe Andropogoneae, subfamily Panicoideae, Poaceae. There are about 156 species in the world, with 66 species occurring in China. They are distributed throughout China, mostly in the Provinces of the south and southwest. They are especially abundant in the mid and lower reaches of the Changjiang and its tributaries. A few species extend to northern China. Saccharinae grasses are usually tall, with many species being cultivated as agricultural crop plants and others possessing commercial value. In many parts of the world, selected species are currently undergoing trials as potential target plants for the exploitation of new energy sources. However, there are many taxonomic problems remaining within Saccharinae and historic studies are both incomplete and inconclusive. Problems exist and opinions differ on the systematic positioning of several genera and species. Conclusions which led to this taxonomic revision utilized the following tools and methods: field works; literature research; the study of 7069 specimens and photos from 17 herbaria; leaf anatomical experiments; analysis of the morphological characters (using statistic methodology).Generic revisions:1. Pseudopogonatherum and Eulalia are quite different in their morphology, leaf epidermis and transverse characteristics. They should be treated as two separate genera. This is consistent with the earlier opinions of Bor and S. L. Chen.2. The leaf anatomical structures and morphological characteristics in Diandranthus, Miscanthus, Triarrhena and Rubimons are almost all the same except for a few differences which exist in Rubimons. According to the result, Diandranthus, Triarrhena and Rubimons should be included in to Miscanthus as described in The Flora of China, but the subgenus Miscanthus subgen. Rubimons (B. S. Sun) Y. C. Liu et H. Peng is usefully aligned to the distinct Rubimons taxa.3. The leaf anatomical structures of Saccharum, Erianthus and Narenga show significant similarity. We agree with Clayton’s suggestion that Erianthus and Narenga should be included into Saccharum.4. The study result of leaf anatomy and morphology in Eccoilopus and Spodiopogon indicate that Eccoilopus should be included with Spodiopogon which agrees with the taxonomic treatment in Genera Graminum, Flora Yunnanica and Flora of China.On Species:1. According to the statistical research and characteristics comparison, we conclude that Microstegium reticulatum should be treated as a synonym of Microstegium vimineum; Miscanthus purpurascence should be included with Miscanthus sinensis; Saccharum arundinaceum var. trichophyllum is simply an extreme variation of Saccharum arundinaceum, and should be treated as a synonym of the latter.2. Specimens labeled as Eulalia siamensis and Eulalia wightii in Chinese herbaria are actually specimens of Eulalia quadrinervis, and specimens labeled as Imperata cylindrica var. cylindrica are in fact specimens of Imperata cylindrica var. major, which means that Eulalia siamensis, Eulalia wightii and Imperata cylindrica var. cylindrica do not occur in China.3. The specimens of Microstegium fasciculatum in Chinese herbaria have long been identified as Microstegium ciliatum. And the descriptions in Flora illustralis Plantarum Primarium Sinicarum Poaceae, Flora Reipublicae Popularis Sinicae Tomus 10(2) and Flora Yunnanica Tomus 9 were wrong in some key details. The correct description of Microstegium ciliatum is available in Flora of China Vol. 22.4. Two new species are found: Miscanthus villosus Y. C. Liu et H. Peng Sp. Nov. and Microstegium butuoense Y. C. Liu et H. Peng Sp. Nov.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&fq=dc.language.iso_filter%3A%E4%B8%AD%E6%96%87&query1=Genera&&fq=dc.project.title_filter%3ASubtrib.%5C+Saccharinae%5C+Kuntze%5C+belongs%5C+to%5C+the%5C+tribe%5C+Andropogoneae%2C%5C+subfamily%5C+Panicoideae%2C%5C+Poaceae.%5C+There%5C+are%5C+about%5C+156%5C+species%5C+in%5C+the%5C+world%2C%5C+with%5C+66%5C+species%5C+occurring%5C+in%5C+China.%5C+They%5C+are%5C+distributed%5C+throughout%5C+China%2C%5C+mostly%5C+in%5C+the%5C+Provinces%5C+of%5C+the%5C+south%5C+and%5C+southwest.%5C+They%5C+are%5C+especially%5C+abundant%5C+in%5C+the%5C+mid%5C+and%5C+lower%5C+reaches%5C+of%5C+the%5C+Changjiang%5C+and%5C+its%5C+tributaries.%5C+A%5C+few%5C+species%5C+extend%5C+to%5C+northern%5C+China.%5C+Saccharinae%5C+grasses%5C+are%5C+usually%5C+tall%2C%5C+with%5C+many%5C+species%5C+being%5C+cultivated%5C+as%5C+agricultural%5C+crop%5C+plants%5C+and%5C+others%5C+possessing%5C+commercial%5C+value.%5C+In%5C+many%5C+parts%5C+of%5C+the%5C+world%2C%5C+selected%5C+species%5C+are%5C+currently%5C+undergoing%5C+trials%5C+as%5C+potential%5C+target%5C+plants%5C+for%5C+the%5C+exploitation%5C+of%5C+new%5C+energy%5C+sources.%5C+However%2C%5C+there%5C+are%5C+many%5C+taxonomic%5C+problems%5C+remaining%5C+within%5C+Saccharinae%5C+and%5C+historic%5C+studies%5C+are%5C+both%5C+incomplete%5C+and%5C+inconclusive.%5C+Problems%5C+exist%5C+and%5C+opinions%5C+differ%5C+on%5C+the%5C+systematic%5C+positioning%5C+of%5C+several%5C+genera%5C+and%5C+species.%5C+Conclusions%5C+which%5C+led%5C+to%5C+this%5C+taxonomic%5C+revision%5C+utilized%5C+the%5C+following%5C+tools%5C+and%5C+methods%5C%3A%5C+field%5C+works%5C%3B%5C+literature%5C+research%5C%3B%5C+the%5C+study%5C+of%5C+7069%5C+specimens%5C+and%5C+photos%5C+from%5C+17%5C+herbaria%5C%3B%5C+leaf%5C+anatomical%5C+experiments%5C%3B%5C+analysis%5C+of%5C+the%5C+morphological%5C+characters%5C+%5C%28using%5C+statistic%5C+methodology%5C%29.Generic%5C+revisions%5C%3A1.%5C+Pseudopogonatherum%5C+and%5C+Eulalia%5C+are%5C+quite%5C+different%5C+in%5C+their%5C+morphology%2C%5C+leaf%5C+epidermis%5C+and%5C+transverse%5C+characteristics.%5C+They%5C+should%5C+be%5C+treated%5C+as%5C+two%5C+separate%5C+genera.%5C+This%5C+is%5C+consistent%5C+with%5C+the%5C+earlier%5C+opinions%5C+of%5C+Bor%5C+and%5C+S.%5C+L.%5C+Chen.2.%5C+The%5C+leaf%5C+anatomical%5C+structures%5C+and%5C+morphological%5C+characteristics%5C+in%5C+Diandranthus%2C%5C+Miscanthus%2C%5C+Triarrhena%5C+and%5C+Rubimons%5C+are%5C+almost%5C+all%5C+the%5C+same%5C+except%5C+for%5C+a%5C+few%5C+differences%5C+which%5C+exist%5C+in%5C+Rubimons.%5C+According%5C+to%5C+the%5C+result%2C%5C+Diandranthus%2C%5C+Triarrhena%5C+and%5C+Rubimons%5C+should%5C+be%5C+included%5C+in%5C+to%5C+Miscanthus%5C+as%5C+described%5C+in%5C+The%5C+Flora%5C+of%5C+China%2C%5C+but%5C+the%5C+subgenus%5C+Miscanthus%5C+subgen.%5C+Rubimons%5C+%5C%28B.%5C+S.%5C+Sun%5C%29%5C+Y.%5C+C.%5C+Liu%5C+et%5C+H.%5C+Peng%5C+is%5C+usefully%5C+aligned%5C+to%5C+the%5C+distinct%5C+Rubimons%5C+taxa.3.%5C+The%5C+leaf%5C+anatomical%5C+structures%5C+of%5C+Saccharum%2C%5C+Erianthus%5C+and%5C+Narenga%5C+show%5C+significant%5C+similarity.%5C+We%5C+agree%5C+with%5C+Clayton%E2%80%99s%5C+suggestion%5C+that%5C+Erianthus%5C+and%5C+Narenga%5C+should%5C+be%5C+included%5C+into%5C+Saccharum.4.%5C+The%5C+study%5C+result%5C+of%5C+leaf%5C+anatomy%5C+and%5C+morphology%5C+in%5C+Eccoilopus%5C+and%5C+Spodiopogon%5C+indicate%5C+that%5C+Eccoilopus%5C+should%5C+be%5C+included%5C+with%5C+Spodiopogon%5C+which%5C+agrees%5C+with%5C+the%5C+taxonomic%5C+treatment%5C+in%5C+Genera%5C+Graminum%2C%5C+Flora%5C+Yunnanica%5C+and%5C+Flora%5C+of%5C+China.On%5C+Species%5C%3A1.%5C+According%5C+to%5C+the%5C+statistical%5C+research%5C+and%5C+characteristics%5C+comparison%2C%5C+we%5C+conclude%5C+that%5C+Microstegium%5C+reticulatum%5C+should%5C+be%5C+treated%5C+as%5C+a%5C+synonym%5C+of%5C+Microstegium%5C+vimineum%5C%3B%5C+Miscanthus%5C+purpurascence%5C+should%5C+be%5C+included%5C+with%5C+Miscanthus%5C+sinensis%5C%3B%5C+Saccharum%5C+arundinaceum%5C+var.%5C+trichophyllum%5C+is%5C+simply%5C+an%5C+extreme%5C+variation%5C+of%5C+Saccharum%5C+arundinaceum%2C%5C+and%5C+should%5C+be%5C+treated%5C+as%5C+a%5C+synonym%5C+of%5C+the%5C+latter.2.%5C+Specimens%5C+labeled%5C+as%5C+Eulalia%5C+siamensis%5C+and%5C+Eulalia%5C+wightii%5C+in%5C+Chinese%5C+herbaria%5C+are%5C+actually%5C+specimens%5C+of%5C+Eulalia%5C+quadrinervis%2C%5C+and%5C+specimens%5C+labeled%5C+as%5C+Imperata%5C+cylindrica%5C+var.%5C+cylindrica%5C+are%5C+in%5C+fact%5C+specimens%5C+of%5C+Imperata%5C+cylindrica%5C+var.%5C+major%2C%5C+which%5C+means%5C+that%5C+Eulalia%5C+siamensis%2C%5C+Eulalia%5C+wightii%5C+and%5C+Imperata%5C+cylindrica%5C+var.%5C+cylindrica%5C+do%5C+not%5C+occur%5C+in%5C+China.3.%5C+The%5C+specimens%5C+of%5C+Microstegium%5C+fasciculatum%5C+in%5C+Chinese%5C+herbaria%5C+have%5C+long%5C+been%5C+identified%5C+as%5C+Microstegium%5C+ciliatum.%5C+And%5C+the%5C+descriptions%5C+in%5C+Flora%5C+illustralis%5C+Plantarum%5C+Primarium%5C+Sinicarum%5C+Poaceae%2C%5C+Flora%5C+Reipublicae%5C+Popularis%5C+Sinicae%5C+Tomus%5C+10%5C%282%5C%29%5C+and%5C+Flora%5C+Yunnanica%5C+Tomus%5C+9%5C+were%5C+wrong%5C+in%5C+some%5C+key%5C+details.%5C+The%5C+correct%5C+description%5C+of%5C+Microstegium%5C+ciliatum%5C+is%5C+available%5C+in%5C+Flora%5C+of%5C+China%5C+Vol.%5C+22.4.%5C+Two%5C+new%5C+species%5C+are%5C+found%5C%3A%5C+Miscanthus%5C+villosus%5C+Y.%5C+C.%5C+Liu%5C+et%5C+H.%5C+Peng%5C+Sp.%5C+Nov.%5C+and%5C+Microstegium%5C+butuoense%5C+Y.%5C+C.%5C+Liu%5C+et%5C+H.%5C+Peng%5C+Sp.%5C+Nov."},{"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.project.fundingorganization_filter&advanced=false&fq=dc.language.iso_filter%3A%E4%B8%AD%E6%96%87&query1=Genera&&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 Xianfeng flora and its palaeoclimte were studied using three quantitative methods. The vegetation and climatic change in Yunnan were also discussed in this paper. The results are summarized as follows:1） 34 species belonging to 9 families, 21 genera were identified in Xianfeng flora. The dominant families are Fagaceae and Lauraceae. Most genera are tropic and subtropic distribution. Consequently, Xianfeng flora is a typical subtropic flora dominanted by Fagaceae and Lauraceae.2）Two new coniferous species were identified, Pinus prekesiya and Tsuga miodumosa. P. prekesiya sp. nov., which belongs to subsection Pinus of subgenus Pinus shows a combination of characters of P. kesiya and P. yunnanensis, but has a closer affinity with P. kesiya which distributes in the humid region of Yunnan and therefore suggests a more humid climate in central Yunnan during the late Miocene than today. The general cooling trend during the late Neogene and topographic change due to the dramatic Tibetan uplift might have cause a vicariance origin of P. kesiya and P. yunnanensis from the ancestral P. prekesiya. Tsuga miodumosa shows a closest affinity with T. dumosa and might represent the ancestral stock of T. dumosa. The discovery of the Tsuga cone confirmed the presence of Tsuga in the Miocene of southwestern China and represents the earliest Tsuga megafossil record in China. The new species provides fossil evidence to support molecular phylogeny study that T. dumosa might be differentiated in the Miocene. It also support the hypothesis that diversification of the genus occurred mainly during Miocene and Pliocene time as global climate cooled and new habitats formed in response to major orogenic events.3）The MATs results from three methods (CA: 17.2-18.0°C；CLAMP3B: 15.7±1.33°C；LMA: 17.2±1.6°C) are higher than present. This indicates that the climate at late Miocene is warmer than today. The MAPs from CA and CLAMP are 1206-1537.4mm and 1297.0±184.7mm respectively, which are higher than today (1003.2mm) obviously. This indicates that the climate is more humid in late Miocene. The differences between precipitation in humid season and dry season suggest the existence of seasonality，but not so strong as today. The palaeoelevation was reconstructed using CA method; the result indicates a lower elevation (1330-1500m) of Xianfeng in late Miocene compared to today.4) The palaeoenvirmental change was discussed based on the comparisons of fossil records and paleoclimate constructions. The results show that, at late Miocene, most floras represented ever-green forests dominanted by Fagaceae and Lauraceae etc. The climate of Yunnan in Miocene was warmer and more humid than today. At Pliocene age, the vegetation type in West Yunnan is still typical ever-green forest, while in the Sanying flora, the species adapt to cold environment like Quercus sect. Heterobalnus increased greatly.5) Two monsoon sensitivity indices were used to illustrate the change of sensitivity of monsoon climate. The results suggest lower seasonality and monsoon sensitivity, especially the winter monsoon sensitivity during late Miocene.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&fq=dc.language.iso_filter%3A%E4%B8%AD%E6%96%87&query1=Genera&&fq=dc.project.title_filter%3AThe%5C+Xianfeng%5C+flora%5C+and%5C+its%5C+palaeoclimte%5C+were%5C+studied%5C+using%5C+three%5C+quantitative%5C+methods.%5C+The%5C+vegetation%5C+and%5C+climatic%5C+change%5C+in%5C+Yunnan%5C+were%5C+also%5C+discussed%5C+in%5C+this%5C+paper.%5C+The%5C+results%5C+are%5C+summarized%5C+as%5C+follows%5C%3A1%EF%BC%89%5C+34%5C+species%5C+belonging%5C+to%5C+9%5C+families%2C%5C+21%5C+genera%5C+were%5C+identified%5C+in%5C+Xianfeng%5C+flora.%5C+The%5C+dominant%5C+families%5C+are%5C+Fagaceae%5C+and%5C+Lauraceae.%5C+Most%5C+genera%5C+are%5C+tropic%5C+and%5C+subtropic%5C+distribution.%5C+Consequently%2C%5C+Xianfeng%5C+flora%5C+is%5C+a%5C+typical%5C+subtropic%5C+flora%5C+dominanted%5C+by%5C+Fagaceae%5C+and%5C+Lauraceae.2%EF%BC%89Two%5C+new%5C+coniferous%5C+species%5C+were%5C+identified%2C%5C+Pinus%5C+prekesiya%5C+and%5C+Tsuga%5C+miodumosa.%5C+P.%5C+prekesiya%5C+sp.%5C+nov.%2C%5C+which%5C+belongs%5C+to%5C+subsection%5C+Pinus%5C+of%5C+subgenus%5C+Pinus%5C+shows%5C+a%5C+combination%5C+of%5C+characters%5C+of%5C+P.%5C+kesiya%5C+and%5C+P.%5C+yunnanensis%2C%5C+but%5C+has%5C+a%5C+closer%5C+affinity%5C+with%5C+P.%5C+kesiya%5C+which%5C+distributes%5C+in%5C+the%5C+humid%5C+region%5C+of%5C+Yunnan%5C+and%5C+therefore%5C+suggests%5C+a%5C+more%5C+humid%5C+climate%5C+in%5C+central%5C+Yunnan%5C+during%5C+the%5C+late%5C+Miocene%5C+than%5C+today.%5C+The%5C+general%5C+cooling%5C+trend%5C+during%5C+the%5C+late%5C+Neogene%5C+and%5C+topographic%5C+change%5C+due%5C+to%5C+the%5C+dramatic%5C+Tibetan%5C+uplift%5C+might%5C+have%5C+cause%5C+a%5C+vicariance%5C+origin%5C+of%5C+P.%5C+kesiya%5C+and%5C+P.%5C+yunnanensis%5C+from%5C+the%5C+ancestral%5C+P.%5C+prekesiya.%5C+Tsuga%5C+miodumosa%5C+shows%5C+a%5C+closest%5C+affinity%5C+with%5C+T.%5C+dumosa%5C+and%5C+might%5C+represent%5C+the%5C+ancestral%5C+stock%5C+of%5C+T.%5C+dumosa.%5C+The%5C+discovery%5C+of%5C+the%5C+Tsuga%5C+cone%5C+confirmed%5C+the%5C+presence%5C+of%5C+Tsuga%5C+in%5C+the%5C+Miocene%5C+of%5C+southwestern%5C+China%5C+and%5C+represents%5C+the%5C+earliest%5C+Tsuga%5C+megafossil%5C+record%5C+in%5C+China.%5C+The%5C+new%5C+species%5C+provides%5C+fossil%5C+evidence%5C+to%5C+support%5C+molecular%5C+phylogeny%5C+study%5C+that%5C+T.%5C+dumosa%5C+might%5C+be%5C+differentiated%5C+in%5C+the%5C+Miocene.%5C+It%5C+also%5C+support%5C+the%5C+hypothesis%5C+that%5C+diversification%5C+of%5C+the%5C+genus%5C+occurred%5C+mainly%5C+during%5C+Miocene%5C+and%5C+Pliocene%5C+time%5C+as%5C+global%5C+climate%5C+cooled%5C+and%5C+new%5C+habitats%5C+formed%5C+in%5C+response%5C+to%5C+major%5C+orogenic%5C+events.3%EF%BC%89The%5C+MATs%5C+results%5C+from%5C+three%5C+methods%5C+%5C%28CA%5C%3A%5C+17.2%5C-18.0%C2%B0C%EF%BC%9BCLAMP3B%5C%3A%5C+15.7%C2%B11.33%C2%B0C%EF%BC%9BLMA%5C%3A%5C+17.2%C2%B11.6%C2%B0C%5C%29%5C+are%5C+higher%5C+than%5C+present.%5C+This%5C+indicates%5C+that%5C+the%5C+climate%5C+at%5C+late%5C+Miocene%5C+is%5C+warmer%5C+than%5C+today.%5C+The%5C+MAPs%5C+from%5C+CA%5C+and%5C+CLAMP%5C+are%5C+1206%5C-1537.4mm%5C+and%5C+1297.0%C2%B1184.7mm%5C+respectively%2C%5C+which%5C+are%5C+higher%5C+than%5C+today%5C+%5C%281003.2mm%5C%29%5C+obviously.%5C+This%5C+indicates%5C+that%5C+the%5C+climate%5C+is%5C+more%5C+humid%5C+in%5C+late%5C+Miocene.%5C+The%5C+differences%5C+between%5C+precipitation%5C+in%5C+humid%5C+season%5C+and%5C+dry%5C+season%5C+suggest%5C+the%5C+existence%5C+of%5C+seasonality%EF%BC%8Cbut%5C+not%5C+so%5C+strong%5C+as%5C+today.%5C+The%5C+palaeoelevation%5C+was%5C+reconstructed%5C+using%5C+CA%5C+method%5C%3B%5C+the%5C+result%5C+indicates%5C+a%5C+lower%5C+elevation%5C+%5C%281330%5C-1500m%5C%29%5C+of%5C+Xianfeng%5C+in%5C+late%5C+Miocene%5C+compared%5C+to%5C+today.4%5C%29%5C+The%5C+palaeoenvirmental%5C+change%5C+was%5C+discussed%5C+based%5C+on%5C+the%5C+comparisons%5C+of%5C+fossil%5C+records%5C+and%5C+paleoclimate%5C+constructions.%5C+The%5C+results%5C+show%5C+that%2C%5C+at%5C+late%5C+Miocene%2C%5C+most%5C+floras%5C+represented%5C+ever%5C-green%5C+forests%5C+dominanted%5C+by%5C+Fagaceae%5C+and%5C+Lauraceae%5C+etc.%5C+The%5C+climate%5C+of%5C+Yunnan%5C+in%5C+Miocene%5C+was%5C+warmer%5C+and%5C+more%5C+humid%5C+than%5C+today.%5C+At%5C+Pliocene%5C+age%2C%5C+the%5C+vegetation%5C+type%5C+in%5C+West%5C+Yunnan%5C+is%5C+still%5C+typical%5C+ever%5C-green%5C+forest%2C%5C+while%5C+in%5C+the%5C+Sanying%5C+flora%2C%5C+the%5C+species%5C+adapt%5C+to%5C+cold%5C+environment%5C+like%5C+Quercus%5C+sect.%5C+Heterobalnus%5C+increased%5C+greatly.5%5C%29%5C+Two%5C+monsoon%5C+sensitivity%5C+indices%5C+were%5C+used%5C+to%5C+illustrate%5C+the%5C+change%5C+of%5C+sensitivity%5C+of%5C+monsoon%5C+climate.%5C+The%5C+results%5C+suggest%5C+lower%5C+seasonality%5C+and%5C+monsoon%5C+sensitivity%2C%5C+especially%5C+the%5C+winter%5C+monsoon%5C+sensitivity%5C+during%5C+late%5C+Miocene."},{"jsname":"The chemistry constitutes and their anti-tobacco mosic virus activity from two species of Simaroubeaceae, namely Brucea javanica (L) Merr. and Harrisonia perforata (Blanco) Merr have been investigated.. By variety of chromatographies over various materials, Eighty-seven compounds were isolated from the two plants and eighty of them were identified， of which twenty-two were new compounds and one of them was a novel nortriterpenoids with unprecedented skeleton and another showed the polymorphism. A series of C-20 quassinoids with potent anti-tobacco mosic virus (TMV) activity was found by the bioassay-guided isolation of the seed of Brucea javanica. The characteristic secondary metabolites of Simaroubeaceae--quassinoids were reviewed. Chapter 1, phytochemistry investigation on the seed of Brucea javanica (L) Merr. has led to isolation of 41 compounds, and 34 of them were identified, including 17 quassinoids with anti-TMV activity. Among them compounds 1 and 2 were new quassinoids. Others were alkaloids, ligands, sequiterpenoids, and so on. Chapter 2, tobacco mosic virus inhibiting activity of quassinoids from Brucea javanica (L) Merr. From bioassay-guide isolation 17 quassinoids with potent anti-TMV activities were isolated from the seeds of Brucea javanica (L) Merr. Based on the results of in vivo and in vitro experiments, it was showed that those compounds can both inhibit virus infection and multiplication of TMV. The anti-TMV structure activity relationships were also discussed. Chapter 3, phytochemistry investigation on the leaves and branches of H. perforata has lead to isolation of 32 compounds and 31 were identified, including 20 new limonoids. Among them 1 was a novel limonoids with unprecedented skeleton, and another showed the polymorphism. Besides, 14 compounds, including 8 limonoids along with some triterpenoids, ligands and flavonoids were isolated from the fruit of H. perforata. Among the 14 compounds 1-3 were novel limonoids which have been isolated from the leaves and branches of this species. The limonoids isolated from H. perforata showed structure similarity with those from the Ptaeroxylaceae and Cneoraceae. Furthermore, most of them were the key intermediates of the biogenetic pathway previously proposed by Dr. Xin Fang of our research group. Based on the biogenetic pathway and structure similarity of limonoids it was suggested that the genus of Harrisonia has a very close relationship with Ptaeroxylaceae and Cneoraceae. Chapter 4, reviewed the progress on the phytochemistry study of the quassinoids of Simaroubaceae. The bioactivities along with proposed biogenetic pathway involving quassinoids reported from the Simaroubeaceae were systemically.","jscount":"1","jsurl":"/simple-search?field1=all&field=dc.project.fundingorganization_filter&advanced=false&fq=dc.language.iso_filter%3A%E4%B8%AD%E6%96%87&query1=Genera&&fq=dc.project.title_filter%3AThe%5C+chemistry%5C+constitutes%5C+and%5C+their%5C+anti%5C-tobacco%5C+mosic%5C+virus%5C+activity%5C+from%5C+two%5C+species%5C+of%5C+Simaroubeaceae%2C%5C+namely%5C+Brucea%5C+javanica%5C+%5C%28L%5C%29%5C+Merr.%5C+and%5C+Harrisonia%5C+perforata%5C+%5C%28Blanco%5C%29%5C+Merr%5C+have%5C+been%5C+investigated..%5C+By%5C+variety%5C+of%5C+chromatographies%5C+over%5C+various%5C+materials%2C%5C+Eighty%5C-seven%5C+compounds%5C+were%5C+isolated%5C+from%5C+the%5C+two%5C+plants%5C+and%5C+eighty%5C+of%5C+them%5C+were%5C+identified%EF%BC%8C%5C+of%5C+which%5C+twenty%5C-two%5C+were%5C+new%5C+compounds%5C+and%5C+one%5C+of%5C+them%5C+was%5C+a%5C+novel%5C+nortriterpenoids%5C+with%5C+unprecedented%5C+skeleton%5C+and%5C+another%5C+showed%5C+the%5C+polymorphism.%5C+A%5C+series%5C+of%5C+C%5C-20%5C+quassinoids%5C+with%5C+potent%5C+anti%5C-tobacco%5C+mosic%5C+virus%5C+%5C%28TMV%5C%29%5C+activity%5C+was%5C+found%5C+by%5C+the%5C+bioassay%5C-guided%5C+isolation%5C+of%5C+the%5C+seed%5C+of%5C+Brucea%5C+javanica.%5C+The%5C+characteristic%5C+secondary%5C+metabolites%5C+of%5C+Simaroubeaceae%5C-%5C-quassinoids%5C+were%5C+reviewed.%5C+Chapter%5C+1%2C%5C+phytochemistry%5C+investigation%5C+on%5C+the%5C+seed%5C+of%5C+Brucea%5C+javanica%5C+%5C%28L%5C%29%5C+Merr.%5C+has%5C+led%5C+to%5C+isolation%5C+of%5C+41%5C+compounds%2C%5C+and%5C+34%5C+of%5C+them%5C+were%5C+identified%2C%5C+including%5C+17%5C+quassinoids%5C+with%5C+anti%5C-TMV%5C+activity.%5C+Among%5C+them%5C+compounds%5C+1%5C+and%5C+2%5C+were%5C+new%5C+quassinoids.%5C+Others%5C+were%5C+alkaloids%2C%5C+ligands%2C%5C+sequiterpenoids%2C%5C+and%5C+so%5C+on.%5C+Chapter%5C+2%2C%5C+tobacco%5C+mosic%5C+virus%5C+inhibiting%5C+activity%5C+of%5C+quassinoids%5C+from%5C+Brucea%5C+javanica%5C+%5C%28L%5C%29%5C+Merr.%5C+From%5C+bioassay%5C-guide%5C+isolation%5C+17%5C+quassinoids%5C+with%5C+potent%5C+anti%5C-TMV%5C+activities%5C+were%5C+isolated%5C+from%5C+the%5C+seeds%5C+of%5C+Brucea%5C+javanica%5C+%5C%28L%5C%29%5C+Merr.%5C+Based%5C+on%5C+the%5C+results%5C+of%5C+in%5C+vivo%5C+and%5C+in%5C+vitro%5C+experiments%2C%5C+it%5C+was%5C+showed%5C+that%5C+those%5C+compounds%5C+can%5C+both%5C+inhibit%5C+virus%5C+infection%5C+and%5C+multiplication%5C+of%5C+TMV.%5C+The%5C+anti%5C-TMV%5C+structure%5C+activity%5C+relationships%5C+were%5C+also%5C+discussed.%5C+Chapter%5C+3%2C%5C+phytochemistry%5C+investigation%5C+on%5C+the%5C+leaves%5C+and%5C+branches%5C+of%5C+H.%5C+perforata%5C+has%5C+lead%5C+to%5C+isolation%5C+of%5C+32%5C+compounds%5C+and%5C+31%5C+were%5C+identified%2C%5C+including%5C+20%5C+new%5C+limonoids.%5C+Among%5C+them%5C+1%5C+was%5C+a%5C+novel%5C+limonoids%5C+with%5C+unprecedented%5C+skeleton%2C%5C+and%5C+another%5C+showed%5C+the%5C+polymorphism.%5C+Besides%2C%5C+14%5C+compounds%2C%5C+including%5C+8%5C+limonoids%5C+along%5C+with%5C+some%5C+triterpenoids%2C%5C+ligands%5C+and%5C+flavonoids%5C+were%5C+isolated%5C+from%5C+the%5C+fruit%5C+of%5C+H.%5C+perforata.%5C+Among%5C+the%5C+14%5C+compounds%5C+1%5C-3%5C+were%5C+novel%5C+limonoids%5C+which%5C+have%5C+been%5C+isolated%5C+from%5C+the%5C+leaves%5C+and%5C+branches%5C+of%5C+this%5C+species.%5C+The%5C+limonoids%5C+isolated%5C+from%5C+H.%5C+perforata%5C+showed%5C+structure%5C+similarity%5C+with%5C+those%5C+from%5C+the%5C+Ptaeroxylaceae%5C+and%5C+Cneoraceae.%5C+Furthermore%2C%5C+most%5C+of%5C+them%5C+were%5C+the%5C+key%5C+intermediates%5C+of%5C+the%5C+biogenetic%5C+pathway%5C+previously%5C+proposed%5C+by%5C+Dr.%5C+Xin%5C+Fang%5C+of%5C+our%5C+research%5C+group.%5C+Based%5C+on%5C+the%5C+biogenetic%5C+pathway%5C+and%5C+structure%5C+similarity%5C+of%5C+limonoids%5C+it%5C+was%5C+suggested%5C+that%5C+the%5C+genus%5C+of%5C+Harrisonia%5C+has%5C+a%5C+very%5C+close%5C+relationship%5C+with%5C+Ptaeroxylaceae%5C+and%5C+Cneoraceae.%5C+Chapter%5C+4%2C%5C+reviewed%5C+the%5C+progress%5C+on%5C+the%5C+phytochemistry%5C+study%5C+of%5C+the%5C+quassinoids%5C+of%5C+Simaroubaceae.%5C+The%5C+bioactivities%5C+along%5C+with%5C+proposed%5C+biogenetic%5C+pathway%5C+involving%5C+quassinoids%5C+reported%5C+from%5C+the%5C+Simaroubeaceae%5C+were%5C+systemically."},{"jsname":"lastIndexed","jscount":"2024-08-21"}],"资助项目","dc.project.title_filter")'>
|
|
|
|
|
