关键词: 小菜蛾, 地理种群, 遗传多样性, ISSR, 聚类分析

Abstract: The genetic diversity of eight characteristic geographical populations of Plutella xylostella from China was investigated with ISSR method using fifteen selective primers in this study in order to clarify the genetic diversity of different geographic populations of P. xylostella. The results showed that total 395 ISSR loci, of which 89.11% are polymorphic, were obtained, and the characteristic ISSR pattern for each P. xylostella individual was detected. The proportion of polymorphic bands (P), Shannon’s index (I) and Nei’s gene diversity index (H) of P. xylostella displayed a high degree of genetic diversity both at the species level (P=89.11%, H=0.2706, I=0.4286) and at the population level (P=88.80%, H=0.2759, I=0.4349). The genetic diversity of P. xylostella was higher in areas of southern China (Yunnan and Hubei) than in areas of northern China (Beijing, Tianjin, Shandong, Heilongjiang, and Gansu). The intra-population genetic variation was the highest in Nankou of Beijing, and the lowest in Haikou of Hainan and Lanzhou of Gansu. In additional, 5.66% genetic variations are from intra-population and 94.34% from inter-population (Nm=8.3399). No obvious genetic differentiation exists among the eight characteristic geographical populations of P. xylostella in this study. The results provide a valuable basis for the pesticide resistance control and the integrated management of the field population of P. xylostella.

Key words: Plutella xylostella, geographical population, genetic diversity, ISSR, cluster analysis