Abstract: A set of 48 SSR markers was used to assess the genetic diversity in 11 natural populations of common wild rice(Oryza rufipogon Griff.)from Hainan Province,China.The results showed that the genetic variability of the common wild rice in Hainan is relatively high(Na=8.3,He=0.716).Seventy alleles(17.6%)were found in only one of the 11 populations and a large number of alleles(77.6%)were at low frequency.For most SSR loci and populations,expected heterozygosities(Nei’s He)under Hardy-Weinberg equilibrium were apparently lower than the observed heterozygosities,indicating a considerable excess of heterozygotes within populations.Genetic variation among populations varied widely,ranging from the lowest diversity values in Yacheng population(Na=1.7,He=0.348)to maximal diversity in Heqing(Na=4.0,He=0.577)and Yelin-B(Na=4.0,He=0.531)populations.A Mantel test revealed that the pairwise Nei’s genetic distance between populations was significantly correlated with geographical distance(r=0.386,P=0.004).Genetic differentiation was weak but significant between populations of East and West Coast regions(Fst=0.048,P=0.024).Of the total differentiation among populations,33.3% was explained by divergence among populations within a region,meaning most of the genetic diversity was due to differences within populations.A mean Nm value of 0.404 suggested a limited gene flow among the assayed populations.Based on the results in genetic diversity and allele frequency analysis,it was suggested that populations both in Heqing and Yelin-B should be given conservation priority.

Key words: Oryza rufipogon, simple sequence repeat, genetic diversity, analysis of molecular variance

摘要： 采用48个SSR标记分析了海南11个普通野生稻自然居群的遗传多样性。结果显示海南普通野生稻自然居群具有较丰富的遗传变异（Na=8.3，He=0.716）。居群内多数等位基因（77.6％）频率较低，其中，70个等位基因仅出现在1个居群中。62.9％的等位基因显著偏离哈迪温伯格平衡，多数居群及等位基因实际杂合度大于期望杂合度，表明居群内自交率低、杂合体过剩。居群间遗传变异差异明显，在11个自然居群中，崖城居群遗传多样性最低（Na=1.7，He=0348），和庆、椰林B两居群遗传变异最为丰富（和庆：Na=4.0，He=0.577；椰林B： Na=4.0，He=0.531）。Mantel测验表明，居群间Nei遗传距离与地理距离呈极显著相关（r=0.386，P=0004）。东、西海岸居群间遗传分化显著但较小（Fst=0.048，P=0024），而居群间遗传分化则较大（Fst=0.335，P < 0.001）。11个自然居群间基因流非常有限（Nm=0.404），表明居群间隔离程度较大。基于居群等位基因数目、基因多样性指数以及基因频率特点，认为海南11个自然居群中和庆和椰林B居群应是优先保护对象。

关键词: 普通野生稻, 微卫星标记, 遗传多样性, 分子方差分析