海南普通野生稻琼海居群与三亚居群的遗传分化

普通野生稻(OryzarufipogonGriff.)是栽培稻的近缘祖先,蕴藏着丰富的优异基因,是宝贵的水稻遗传资源。普通野生稻主要分布在我国的南方地区,海南岛是我国普通野生稻的主要分布区之一,野生稻的遗传多样性曾经非常丰富。三亚是海南岛典型的热带地区,是普通野生稻主要的分布区。最近在海南琼海发现一个原生境普通野生稻居群,尚不清楚海南普通野生稻琼海居群与三亚居群之间的遗传关系。本研究采用37个SSR标记从SSR座位的多态率、SSR座位的基因杂合性、两居群间的遗传相似性和遗传距离以及两居群间的遗传分化等四方面,对海南普通野生稻琼海居群与三亚居群进行了遗传分析,旨在为海南普通野生稻的深入研究提供基础。结果表明SSR座位在两群体中存在较高的遗传变异,且其在普通野生稻三亚居群的遗传变异高于在普通野生稻琼海居群的遗传变异。SSR座位在琼海居群中的多态率为81.0811%,在三亚居群中的多态率为91.8919%;观察杂合性、理论杂合性、非偏性杂合性在三亚居群中的平均值为0.5651、0.4449、0.4661,高于在琼海居群中的相应平均值(0.4097、0.2057、0.2670)。根据Nei遗传相似性和遗传距离普通野生稻琼海居群与三亚居群间的遗传相似性为0.6385,遗传距离为0.4486。FST检验表明,两群体之间存在着中等程度的遗传分化(FST=0.3909),表明这两个普通野生稻居群内存在着60.91%的遗传变异。

The Genetic Differentiation of Common Wild Rice Populations between Qionghai and Sanya in Hainan Island

The common wild rice (Oryza rufipogon Griff.) is the close relative ancestor of Chinese cultivated rice, which contains abundant useful genes and is an important rice genetic resource. The common wild rice is wildely distributed in the sourth region of China, of which Hainan island is the main rice-distribute region. And Sanya is an typical tropic region and is the main rice-distribute region in Hainan island. Recently, a in situ population of common wild rice was found in Qionghai in Hainan island, the genetic relationship of which with Sanya common wild rice population is unkown. We studied the SSR polymorphic percentage, SSR heterozygosity, genetic identity and distance between the two populations and Wright's FST to detemine the above two poplations relationship, using 37 SSR markers in order to provide information for the deep study of common wild rice in Hainan island. The results showed that SSRs have more genetic variability in Sanya population than in Qionghai population. The percentage of SSR loci polymorphism is 81.0811% in Qionghai population and 91.8919% in Sanya population. The values of the direct count, expected and unbiased heterozygosity are 0.5651?0.4449?0.4661 in Sanya population respectively, which are higher than those corresponding values (0.4097, 0.2057, 0.2670) in Qionghai population. The genetic identity and distance between the two populations are 0.6385, 0.4486, respectively, based on Nei's arithmetic for genetic identity and distance. The results indicated that there were moderate genetic differentiation between Qionghai and Sanya populations based on FST value (FST=0.3909), which imply that 60.91% of the total genetic variation exists within populations.