基于SSR标记的8个山荆子居群遗传多样性和遗传关系分析

Analyses of genetic diversity and genetic relationship of eight populations of Malus baccata based on SSR marker

采用10对SSR引物对8个山荆子〔Malus baccata(L.)Borkh.〕居群140个单株的基因组总DNA进行PCR扩增,并据此对8个居群的遗传多样性和遗传关系进行了分析。结果表明:用10对SSR引物共扩增出91条带,多态性条带百分率达100.00%。8个居群的遗传多样性参数差异较大,有效等位基因数为1.437 9～1.535 0,Nei’s基因多样性指数为0.256 0～0.309 2,Shannon信息指数为0.376 7～0.459 2,多态性条带百分率为64.84%～85.71%。居群间的有效等位基因数为1.616 9,Nei’s基因多样性指数为0.355 1,Shannon信息指数为0.528 5,均明显高于居群内;8个居群间的基因流为1.739 5,基因分化系数为0.223 3,显示居群间的基因交换较多。UPGMA聚类分析结果表明:在Nei’s遗传距离0.148 6处,8个居群被分为3组,河北塞罕坝居群单独为一组,山西五台山居群和北京东灵山居群为一组,其余5个居群为一组。据此推测:山荆子起源于中国华北和东北地区,山西灵空山、黑龙江小兴安岭、吉林长白山和山西中条山居群可能是其遗传多样性的核心居群。

PCR amplification of total genomic DNA from 140 individuals of eight populations of Malus baccata （L.） Borkh. was carried out by using ten pairs of SSR primers, and hereby, their genetic diversity and genetic relationship were analyzed. The results show that there are totally 91 bands amplified by ten pairs of SSR primers and percentage of polymorphic band is 100.00%. The difference of genetic diversity parameters of eight populations is great, and effective number of allele is 1. 437 9- 1. 535 0, Nei＇ s gene diversity index is 0. 256 0-0. 309 2, Shannon information index is 0.376 7- 0. 459 2, percentage of polymorphic band is 64.84% -85.71%. The effective number of allele, Nei＇ s gene diversity index and Shannon information index among eight populations are 1. 616 9, 0. 355 1 and 0. 528 5, respectively, which is obviously higher than those within population. The gene flow and gene differentiation coefficient of eight populations are 1. 739 5 and 0. 223 3, respectively, indicating that the gene exchange among populations is more. The result of UPGMA cluster analysis shows that eight populations of M. baccata are divided into three groups where Nei＇ s genetic distance is：0. 148 6. In which, the population in Saihanba of Hebei Province is a group individually, two populations in Mt. Wutai of Shanxi Province and Mt. Dongling of Beijing City are a group, the other five populations are a group. Based on these results, it is presumed that M. baccata is originated from the North and Northeast of China, M. baccata populations in Mt. Lingkong of Shanxi Province, Xiaoxing＇ anling of Heilongjiang Province, Mt. Changbai of Jilin Province and Mt. Zhongtiao of Shanxi Province may be core populations of genetic diversity.