栲树天然群体遗传结构的RAPD分析

利用RAPD分子标记对 5个栲树 (CastanopsisfargesiiFranch .)天然群体共计 188个个体的遗传多样性和群体遗传结构进行了分析。 4 1个随机寡核苷酸引物共检测到 385个位点 ,其中多态位点 15 7个 ,占 4 0 .78%。物种水平的Shannon多样性指数I=0 .4 5 97,Nei基因多样度h =0 .2 96。遗传变异分析表明 ,栲树群体的遗传变异主要存在于群体内 ,利用Shannon多样性指数估算的分化 (Hsp_Hpop) /Hsp=0 .0 4 76 ,遗传分化系数Gst =0 .0 4 2 9,分子方差分析 (AMOVA)也证实了这一结论 ,群体内的变异组分占了 94 .97% ,群体间变异只占 5 .0 3%。AMOVA分析结果的显著性检验也表明 ,群体间及群体内个体间均呈现出显著分化 (P <0 .0 0 1)。

Analysis of Genetic Structure of Natural Populations of Castanopsis fargesii by RAPDs

Genetic diversity and population genetic structure in 188 individuals from five natural populations of Castanopsis fargesii Franch. were studied by RAPD markers. Three hundred and eighty_five loci were identified with 41 oligonucleotide primers, out of which 157 loci were polymorphic and accounted for 40.78% of total genetic diversity at species level. Shannon's indices of diversity ( I ) and Nei's gene diversity ( h ) were 0.459 7 and 0.296 at the species level, respectively. The result showed that genetic variation of C. fargesii populations mainly existed within populations. Genetic differentiation ( Hsp_Hpop)/Hsp estimated with Shannon's index of diversity and coefficient of gene differentiation ( Gst ) were 0.047 6 and 0.042 9 respectively, which were confirmed by the analysis of molecular variance (AMOVA). Therefore, it is apparent that within_population variation accounted for 94.97% and among_populations variation accounted for only 5.03% of the total genetic diversity. AMOVA also indicated that there was significant differentiation among populations as well as among individuals within a population.