基于微卫星标记的桃蚜种群寄主遗传分化

桃蚜Myzus persicae(Sulzer)是寄主范围最广、危害最大的蚜虫种类之一。为了探明桃蚜在不同寄主上的遗传分化特点,采用微卫星分子标记技术,对西兰花、桃树、辣椒上的桃蚜种群进行遗传多样性和遗传结构研究。结果表明,在所选用的5个微卫星位点上共检测到38个等位基因,平均每个位点的等位基因数达到7.6个,桃树种群遗传多样性最高,这可能是因为各种夏寄主上的桃蚜迁回桃树上越冬,从而使多种等位基因和基因型得以聚集的原因。等位基因频率差异分析显示西兰花种群、桃树种群和辣椒种群两两之间(除了桃树06种群和辣椒06种群之间没有遗传分化外)都出现了明显遗传分化,相比之下桃树种群和辣椒种群的分化程度要比桃树种群和西兰花种群的分化程度低,这可能预示着西兰花寄主上的桃蚜正在向远离桃树和辣椒种群的方向进化。

Genetic differentiation of Myzus persicae based on host plants revealed by using microsatellites

Myzus persicae （Sulzer） is one of the most polyphagous and serious aphid pests in agriculture and horticulture. For detecting the genetic variation in aphid populations on different host plants, we analyzed the genetic structure and diversity of M. persicae populations from broccoli, peach tree and pepper, using five microsatellite loci. In all, 38 alleles were detected at the five microsatellite loci. The population from peach tree exhibited the highest allelic and genotypic diversity, which should be related to the aggregation of alleles and genotypes occurred when individuals return to peach tree for overwintering. Allelic frequency analysis indicated that significant differentiation existed between any two of the three populations from the three host plants. However, the genetic differentiation between peach population and pepper population was more remarkable than that between broccoli population and peach population. The results imply that the broccoli population is genetically deviated from the peach population and pepper population.