This study determined the sequences of chloro-plast DNA(cpDNA)trnL-F non-coding regions of indi-viduals of a tropical coniferous species,Dacrydium pectinatum,collected from 12 natural populations located in Hainan Pro...This study determined the sequences of chloro-plast DNA(cpDNA)trnL-F non-coding regions of indi-viduals of a tropical coniferous species,Dacrydium pectinatum,collected from 12 natural populations located in Hainan Province,southern China.Sequence length varied from 868 bp to 876 bp,indicating length polymorphism.Base com-position in the sequences was high in A+T content between 64.17%and 64.95%,and no recombination event occurred(Rm=0).Thirty haplotypes were identified based on statis-tical parsimony algorithm by running the TCS program.Populations of D.pectinatum in Hainan were lacking ge-netic differentiation.Such a deduction was supported by the observed FST values(0.00),AMOVA(24.17%of molecular variance attributed to difference among populations,P>0.05),high values of Nm(ranging from 1.92 to 2.50)and the branching structure in neighbor-joining(NJ)tree con-structed from haplotypes.A‘star-like’pattern was exhibited in the TCS network of trnL-F haplotypes,and majority of the haplotypes coalesced near the tips in NJ tree.Gene ge-nealogies of cpDNA haplotypes proposed a recent popula-tion expansion of D.pectinatum in Hainan,which was fur-ther supported by the results from Tajima’s D test and mis-match distribution analysis.Our data,in conjunction with geological and palynological evidences,showed that in the Holocene,due to global warming,refugee populations of D.pectinatum in Hainan might experience a range expan-sion.展开更多
Random amplification polymorphicDNA(RAPD)markers were used to assess the genetic variations and the evolutionary relationships among all 14 individuals of a critically endangered Euryodendron excelsum(Theaceae)populat...Random amplification polymorphicDNA(RAPD)markers were used to assess the genetic variations and the evolutionary relationships among all 14 individuals of a critically endangered Euryodendron excelsum(Theaceae)population distributed in Ba Jia Zhen,Yangchun,Guangdong,China.Twenty-three random primers detected 156 sites,out of which 95(60.26%)were polymorphic loci.The number of the observed alleles was 1.6090,and the number of the effective alleles was 1.3471.Nei’s gene diversity was 0.1993,and Shannon index was 0.1534.A relatively high level of genetic variation was identified in E.excelsum.An unweighted pair group method with arithmetic mean(UPGMA)tree established from Jaccard similarity coefficients suggested that 14 individuals were clustered into two subgroups and that the No.2 plant was genetically distant from the rest of the individuals.The UPGMA clustering was also supported by a principle components analysis of RAPD phenotypic data.The management and conservation strategy of E.excelsum was proposed based on our results.展开更多
基金supported by the National Natural Science Foundation of China (Nos.30170789 and 30270153)the Natural Science Foundation of Guangdong Province,China (No.011125).
文摘This study determined the sequences of chloro-plast DNA(cpDNA)trnL-F non-coding regions of indi-viduals of a tropical coniferous species,Dacrydium pectinatum,collected from 12 natural populations located in Hainan Province,southern China.Sequence length varied from 868 bp to 876 bp,indicating length polymorphism.Base com-position in the sequences was high in A+T content between 64.17%and 64.95%,and no recombination event occurred(Rm=0).Thirty haplotypes were identified based on statis-tical parsimony algorithm by running the TCS program.Populations of D.pectinatum in Hainan were lacking ge-netic differentiation.Such a deduction was supported by the observed FST values(0.00),AMOVA(24.17%of molecular variance attributed to difference among populations,P>0.05),high values of Nm(ranging from 1.92 to 2.50)and the branching structure in neighbor-joining(NJ)tree con-structed from haplotypes.A‘star-like’pattern was exhibited in the TCS network of trnL-F haplotypes,and majority of the haplotypes coalesced near the tips in NJ tree.Gene ge-nealogies of cpDNA haplotypes proposed a recent popula-tion expansion of D.pectinatum in Hainan,which was fur-ther supported by the results from Tajima’s D test and mis-match distribution analysis.Our data,in conjunction with geological and palynological evidences,showed that in the Holocene,due to global warming,refugee populations of D.pectinatum in Hainan might experience a range expan-sion.
基金supported by National Natural Science Foundation of China (No.30271094)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry (No.[2003]406)the“100 Talent Project”,the Chinese Academy of Sciences (No.05052903).
文摘Random amplification polymorphicDNA(RAPD)markers were used to assess the genetic variations and the evolutionary relationships among all 14 individuals of a critically endangered Euryodendron excelsum(Theaceae)population distributed in Ba Jia Zhen,Yangchun,Guangdong,China.Twenty-three random primers detected 156 sites,out of which 95(60.26%)were polymorphic loci.The number of the observed alleles was 1.6090,and the number of the effective alleles was 1.3471.Nei’s gene diversity was 0.1993,and Shannon index was 0.1534.A relatively high level of genetic variation was identified in E.excelsum.An unweighted pair group method with arithmetic mean(UPGMA)tree established from Jaccard similarity coefficients suggested that 14 individuals were clustered into two subgroups and that the No.2 plant was genetically distant from the rest of the individuals.The UPGMA clustering was also supported by a principle components analysis of RAPD phenotypic data.The management and conservation strategy of E.excelsum was proposed based on our results.
