Abstract:

【Objective】 The genetic similarity and genetic difference of Myzus persicae among geo-populations from different regions in Gansu province were detected to analyze the relationship between genetic distance and geographical distance and elevations. The objective was to acquire molecular evidences of the genetic differentiation and migration of peach aphids. 【Method】 The genetic similarity and clustering of 13 geo-populations of Myzus persicae were analyzed using 7 SSR primers. 【Result】 A total of 43 polymorphic loci were detected with 7 SSR primers, the percentage of polymorphic bands (PPB) was 95.56%. For these geo-populations, the average number of alleles (Na) per locus was 1.3333, and the effective number of alleles (Ne) was 1.2293. The Nei′s gene diversity (H) and Shannon information index (I) were 0.1311 and 0.1898, the percentage in polymorphic loci was 33.33%. The genetic diversity of Lintao, Linxia, Minxian and Lanzhou populations was higher, and the diversity of Tianshui, Jiuquan and Zhangxian was lower compared with others. The cluster analysis showed that the populations could be divided into Hexi and Hedong groups. Analysis of AMOVA showed that there were about 1.76% of the total variations between two groups, 17.21% of the total variations among populations, 81.03% presented within populations. Mantel test revealed that there were no significant correlation between genetic distance and geographical distance and elevations. 【Conclusion】 Gansu populations of Myzus persicae have relatively high levels of genetic diversity. The genetic differentiation was mainly from inner populations and gene is seldom exchanged among populations, so genetic drift occurres easily. North of Shanxi, East of Gansu and South of Gansu are the source regions of Myzus persicae in the middle part of Gansu.

Key words: Myzus persicae, geographical population, SSR, genetic similarity, gene exchange, migration