| Heterobostrychus aequalis(Waterhouse)is one of the familes of Coleoptera, belong to Bostrichidae, Heterobostrychus. It is an important borer, common in tropical and subtropical regions, feeding miscellaneous, hosts a wide destructiveness of modern bamboo, wood, rattan decoration. It is also the risk of foreign plant quarantine pests.In this study, Heterobostrychus aequalis(Waterhouse) in 7 countries in Southeast Asia is the object of the study, their genetic diversity using RAPD technique was analyzed and using mtDNA COI gene phylogeny and relationship to their conduct of the study. The major findings are as follows:1. CTAB method and SDS were used method of Heterobostrychus aequalis(Waterhouse) genomic DNA samples were extracted, extraction results showed that both methods can extract genomic DNA, and genomic DNA concentration and quality suitable for molecular biology.2. On the Heterobostrychus aequalis(Waterhouse) populations RAPD-PCR system was optimized to establish a suitable Heterobostrychus aequalis(Waterhouse)populations RAPD analysis of PCR reaction system. On this basis, from the 40 primers screened, good stability, high polymorphism of seven random primers as a primer RAPD experiment. This seven random primers amplified 226 bands, obtained fragment size of 100-2000bp. Analyzed by POPGENE 3.2 software, the average percentage of polymorphic loci (PPL) in Heterobostrychus aequalis(Waterhouse)was 6.31%, the observed number of alleles (Ao) was 1.992, the effective number alleles (Ae) was 1.531, Nei's genetic diversity (HE) was 0.33, and Shannon's information index (H) was 0.504. The results showed that the genetic diversity was rich in Heterobostrychus aequalis(Waterhouse)population, the influence of genetic structure it may be due to geography and climate conditions of each population. This paper has three main genetic diversity index, the percentage of polymorphic loci (PPL), Nei's genetic diversity (HE) and Shannon's information index (H) were highest in the population of Thailand, 10%,0.036and 0.055, respectively; the second is Malaysia's population, PPL,HE and H were 8.33%,0.034 and 0.05, respectively. The other populations are below that level. The observed number of alleles and effective number alleles were highest in the population of Thailand and Malaysia.According to seven geographical populations of genetic distance and cluster analysis diagrams, populations of genetic clustering results are: the population of Vietnam and Thailand genetic similarity is the largest, genetic identity is 0.778, and genetic distance is corresponding minimum, genetic distance is 0.251. The population of Malaysia and Laos genetic identity is 0.467, and genetic distance is 0.761. According to cluster analysis results, these is two branches during the seven populations, the population of Thailand,Vietnam,Myanmar and Laos are together, the population of Malaysia,Singapore and Indonesia are together, it related to geographical distances. From a geographic perspective, Vietnam, Myanmar, Laos, Thailand and adjacent, are located in Southeast Asia, Indochina, Malaysia and in Malaysia, Indonesia and Singapore, across the sea, the geographical distribution is consistent with the RAPD. Cluster analysis shows that the geographical differences result in genetic differences between populations of Heterobostrychus aequalis(Waterhouse).3. Different geographical populations of Heterobostrychus aequalis(Waterhouse) mitochondrial DNA COI gene was cloned and sequenced to obtain the sequence. Analysis of the sequence alignment, the similarity coefficients was 95.98%. Using neighbor joining (NJ) and maximum parsimony (MP) constructed a phylogenetic tree, the results showed that: Myanmar and Vietnam, Heterobostrychus aequalis ( Waterhouse ) has closest relationship and little genetic differentiation.In this thesis, two kinds of molecular markers were used to study the genetic diversity in 7 different geographical populations of Heterobostrychus aequalis(Waterhouse), the geographic populations of both methods to analyze genetic variation compared with Heterobostrychus aequalis(Waterhouse). The study could constrcucted the foundation for further study of molecular biology to Heterobostrychus aequalis(Waterhouse). Due to the impact of collection, the species selected are still very limited, pending further study, but it can be seen that in this experimental study, the geographical distribution have some impact on genetic diversity of the same species. |
