广西药用野生稻遗传多样性分析及SSR引物数量对遗传多样性结果的影响研究

采用25对SSR分子标记,对广西境内采集的1610份药用野生稻材料进行遗传多样性和聚类分析,其中检测到等位变异181个,有效等位基因数Ae范围为1.0094(RM240)~2.2674(RM488),平均值为1.3568;期望杂合度He范围为0.0093(RM240)~0.5591(RM448),平均值为0.2112;Shannon多样性指数I在0.0393~0.9296之间变动,平均值为0.3624。数据表明,广西药用野生稻遗传多样性较为丰富,12个药用野生稻地理居群按遗传多样性指数大小排序为:梧州-3南宁-1梧州-2梧州-1南宁-2玉林-2贵港-2梧州-4玉林-3玉林-1贺州贵港-1,其中指数高的居群均分布于梧州市和南宁市两地,因此确定了这两地为广西药用野生稻的遗传多样性中心。通过不同数量的SSR引物对药用野生稻材料间相似系数矩阵进行相关性测验,结果显示当引物按照PIC值降序排列时,10对引物即达到较好聚类效果,升序排列时,21对引物即达到较好聚类效果。研究表明,在进行药用野生稻大居群聚类分析时,SSR引物适宜数量应多于21对,最低不得少于10对。

Study on genetic diversity of Oryza officinalis Wall in Guangxi province and the effect of the number of SSR primers on genetic diversity analysis

Guangxi province has the most abundant Oryza officinalis Wall germplasm resource in China. In this study, 1610 Oryza officinalis individuals which collected from all over Guangxi in situ sites, were used for genetic diversity analysis with 25 SSR markers. 181 polymorphic bands were detected, and the effective number of alleles (Ae) ranged from 1.0094 to 2.2674 and averaged at 1.3568. The expected heterozygosity (He) ranged from 0.0093 to 0.5591 and averaged at 0.2212. The Shannon-Weaver information index ranged from 0.0393-0.9296 and averaged at 0.3624. We confirmed that Wuzhou and Nanning are the genetic diversity center of Oryza officinalis in Guangxi and in China as well. Mantel correlation test was carried out to examine the correlation among cophenetic matrices, the results showed that more than 21 pairs of primer (no less than 10 pairs) would be the appropriate number for genetic diversity analysis of Oryza officinalis Wall populations.