广东乳源县大桥镇野生大豆自然居群遗传结构分析

Genetic analysis of wild soybean papulations growing in Daqiao Town of Ruyuan County,Guangdong Province

【目的】粤北山区的野生大豆是全世界分布最南端的野生大豆自然居群,本研究对来源于广东乳源县大桥镇的一个自然居群的遗传多样性进行分析,为该自然居群的原位保护和异位保护提供理论依据.【方法】在广东乳源县大桥镇发现的1个野生大豆自然居群中根据地形等距离采集了98株野生大豆样本,分别用22和73对微卫星(SSR)引物对其遗传结构进行了分析.【结果和结论】在98个样品中分别检测到27和85个等位变异,平均位点等位变异数分别为1.23和1.02个,居群期望杂合度(He)平均为0.02.聚类结果表明,可将居群分为3个部分,沿坪乳公路两侧分布的野生大豆表现出相对较高的遗传多样性.综合各指标表明,广东乳源县大桥镇居群的遗传多样性较低,在保护和利用时选取部分单株即可代表该群体;在对居群遗传多样性初步评价时,用均匀分布的30对引物即可.

[ Objective] The natural wild soybean populations distributing in the north of Guangdong are the extreme southern limit in the world. The objective of the present study was to explore the genetic characteristics of one natural wild soybean population from Daqiao Town of Ruyuan County in Guangdong Province, providing the base for in situ or ex situ conservation for this population. [ Method ] Ninety-eight wild soybean samples were collected from one natural population of wild soybean growing in Ruyuan County, Guangdong Province. In order to facilitate the selection of the natural reserve of wild soybean, genetic diversity of this population was evaluated using 22 and 73 SSR makers. [ Result and conclusion] The results showed that 27 and 85 alleles were detected with an average of 1.23 and 1.02 alleles per marker respectively. Expected heterozygosity （He） was 0.02 averagely. The cluster analysis showed that the population could be divided into three subgroups. The population distributing along both sides of Pinru road showed a higher genetic diversity. The above analysis indicated that the genetic diversity of this population was very low. Thirty selected SSR markers may clarify the primary evaluation of genetic diversity population.