Genetic Diversity In Dendrolimus (Lepidoptera) Geographical Populations And Its Relationship With Ecological Factors

This study, by use of ISSR technique, examined the genetic structure and divergence among the 9 natural populations of the pine caterpillars(Dendrolimus punctatus spectabilis; Dendrolimus punctatus tabulaeformis; Dendrolimus superans)collected from different areas in Hebei, Liaoning and Shandong.Base on the amplification bands,using POPGENE software, genetic diversity and genetic similarities were analyzed.Besides,cluster analysis were analyzed on all the individuals of pine caterpillars by NTSYS PC-22.10. The correlation analysis was analyzed between the genetic diversity,genetic distance within populations and environmental factors.This test has developed a set of optimized response system of inter-simple Sequence Repeats Polymophism (ISSR),which provides a powerful tool for investigation of genetic variation of 9 natural populations(Dendrolimus spectabilis; Dendrolimus tabulaeforrnis; Dendrolimus superans). Shannon'index shows highest genetic diversity in Weichang population(Dendrolimus superans) and lowest genetic diversity in Shenyang population(Dendrolimus spectabilis),which is identical with Nei's index.Different geographical groups in the same populations has a genetic divergence in some extent.Generally,the genetic distance between groups in the same population is certainly related with the geographical distance and host.genetic similarities and cluster analysis shows that inter-species heredity difference is obviously bigger than the homogeneous between populations in the heredity difference,which reflects the heredity difference degree is consistent from the DNA level with the phenotype level. Dendrolimus spectabilis has nearer genetic distance with Dendrolimus.tabulaeformis than Dendrolimus superans, which is identical with that researched in sexual information of pine caterpillars.Correlation analysis by SPSS software in four Dendrolimus spectabilis populations of different geographical areas shows a significant negative relation between genetic diversity and elevation, and the genetic diversity within populations was positively related with the annual temperature and moisture. In opposite, the genetic diversity was weakly related with latitude. Besides, There was a positive relation between the genetic distance and and the distance of elevation,which shows that geographical isolation has obstruct effect on gene interflow.