我国盾叶薯蓣居群遗传结构分析

利用随机扩增多态DNA(RAPD)标记，分析研究了中国11个盾叶薯蓣居群82个个体的遗传多样性与遗传结构，15个寡聚核苷酸引物扩增共得到108条带，其中96条为多态带，占88．89％。Shannon多样性指数(I)为0．3093，居群水平的变异从0．1564到0．3098，物种水平的Nei基因多样度(h)为0．2499，居群水平的变化范围为0．1607到0．2137。遗传变异分析表明，物种水平的基因分化系数Gst为0．3415，居群间的基因流Nm为0．9641，居群间遗传交换小。分子方差分析(AMOVA)表明，居群内变异为68．96％，地区间变异为19．45％，居群问变异为11．58％。聚类结果以长江为界，将盾叶薯蓣分为南北两个大类群。研究结果对盾叶薯蓣种质的迁地保护有重要意义。

Population Genetic Structure of Dioscorea zingiberensis in China

Genetic diversity and population genetic structure in 82 individuals from 11 wild and cultivated populations of Dioscorea zingiberensis C.H.Wright.were studied by RAPD markers. 108 loci were indentified with 15 oligonucleotide primers, out of which 96 loci were polymorphic and account for 88.89% of total genetic diversity at species level.Shannon's indices of diversity(I) varied from 0.1564 to 0.3098, and Nei's gene diversity (h) varied from 0.1607 to 0.2137 at population level, with I=0.3093 and h=0.2499 at the species level, respectively. Genetic variance analysis showed the coefficient of gene differentiation is 0.3415 at species level,and the gene flow among populations of D.zingiberensis is 0.9641.Analysis of molecular variance(AMOVA) showed that the main genetic variance existed within population, which accounted for 68.96%, variance among regions and populations were only 19.45% and 11.58%, respectively. Clustering analysis grouped all the 11 populations into 2 major groups which can be separated by Yangtze river.The results have a guidance to the ex.situ.conservation of D.zingiberensis germplasm.