利用SRAP标记研究海南野生稻的遗传多样性与遗传分化

Study on Genetic Diversity and Differentiation of Three Wild Rice Species in Hainan Using SRAP Markers

利用8对多态性较好的SRAP引物对海南120份普通野生稻、55份疣粒野生稻和26份药用野生稻进行扩增,在检测到的219个位点中,普通野生稻的多态性位点率为74.89%,疣粒野生稻为42.47%,药用野生稻25.11%。Shannon多样性指数以普通野生稻最高为0.3277,疣粒野生稻为0.2044,药用野生稻最低为0.1113。UPGMA聚类分析结果显示供试材料与地理来源相一致,相关性强,各居群个体间没有出现任何交叉。普通野生稻总群体基因多样性为0.2135,群体内基因多样性显著高于居群间基因多样性,说明普通野生稻居群遗传分化不显著,遗传多样性主要来自于居群内。基于Nei's基因多样度和Shannon多样性指数特点,认为实施保护策略时,优先保护遗传多样性最丰富的WDL和WDA居群。疣粒野生稻居群存在中等程度的遗传分化,建议原生境保护;药用野生稻居群数量较少,建议原生境保护。

Using SRAP markers with eight primer combinations, the genetic diversity was assessed within and among seven natural populations of wild rice species in Hainan,a total of 219 alleles were detected in 120 accessions of Oryza rufipogon,55 accessions of Oryza meyeriana, and 26 accessions of Oryza officinalis, the polymorphic loci were 74. 89% ,42.47 % , and 25.11% respectively. Values obtained for Shannon＇s information index （I） suggested that O. rufipogon were 0. 3277 showing the highest genetic diversity, O. meyeriana were 0. 2204, and O. officinalis were 0. 1113 showing the lowst diversity. UPGMA cluster analysis showed that all individuals of each population formed a distinct cluster, which according to the geographical origin, the individuals within each population of wild rice with no cross to others. The gene diversity in total set of O. rufipogon groups were 0. 2135 ,and its average gene di- versity was higher within than among populations, suggesting of genetic differentiation among O. rufipogon populations was not significant,meaning most of the genetic diversity was due to differences within populations. Based on the resuits of Nei＇s genetic diversity and Shannon＇s information index analysis,it was suggested that populations in WDL and WDA should be given conservation priority. In addition,in situ conservation should be carried out for both O. meyeriana and O. officinalis because of a moderate genetic differentiation among populations or a small population size.