Single Strand Conformation Polymorphism And Microsatellite Polymorphisms Studies On Population Differentiation Of H.assulta

The molecular genetic marker techniques-Single Strand Conformation Polymorphism(SSCP) and Microsatellite Polymorphisms were used to study the population differenti-ation of H. assulta of different geographies and different hosts and H. armigera of different hosts. The subject of this study is to interpret their evolution and genetic variation inner and inter-population from molecular biology.In SSCP analysis, four pairs of primers were selected to do PCR amplification, So three fragments of DDC genes (730bp, 640bp, 520bp) and one fragment COI gene (SOObp) were amplified. The amplified results were shown by silver staining and could differentiate from H. assulta-* H. armigera and Heliothis viriplaca, but not the same insect population of different hosts or geographies. The results of SSCP also showed that the genes of DDC and COI were highly conservative in the population of H. assulta^ H. armigera and Heliothis viriplaca and different among species.The results of microsatellite polymorphisms were analyzed by Similarity Index (SI), Genetic distance(D), Polynum and Genediv to study the genetic variation in and among insect populations. The cluster analysis based on D of H. assulta of different geographic population showed that the affinity relations are closely related between Henan and Beijing populations compared with Hunan population. The Genediv between Henan and Beijing54populations is 0.2599, 0.2685 between Henan and Hunan populations. It demonstrated that the genetic variation between Henan and Beijing populations is lower, as is in accord with the cluster analysis based on D.The Genediv (0.1368) between Henan populations on pepper and tobacco is lower than that among geographic populations. This revealed that the gene flow among different hosts is more frequent.The Polynum of Henan H. assulta population on pepper is highest, which showed that its genetic variation is higher; Compared to the population fed in laboratory, that the Polynum of nature population is higher shows that the hybrid genes of nature population increased because of mating randomly.The Genediv showed that the populations of H. armigera on tomato and tobacco had close affinity relation and distant to the population on cotton. According to the standard of population differentiation in this study, the results that the Genedives between H. assulta and H. armigera, and these two parents and their hybrids were all higher than 0.2 revealed that the two hybrids were still two species but not one.