Basic Study On Population Differentiation Of Bactrocera Dorsalis (Hendel) In Fujian

Oriental fruit fly, Bactrocera dorsalis (Hendel), can infest more than 250 species of fruits and vegetables belong to 40 families, is a major pest of many economical tropical and subtropical fruits. In China, oriental fruit fly distributed mainly in the southern provinces, Fujian province is a severe damaged region. Economic loss caused by oriental fruit fly is over billion yuan. Therefore, It is imperative to do fundamental research of oriental fruit fly for sustainable control and comprehensive management.In this study, partial mtDNA COI gene sequences and rDNA-ITS1 gene sequences were sequenced of oriental fruit fly geographic populations. Partial mtDNA COI gene sequences of rearing populations was also sequenced, 47 fragments were received. The population genetic differentiation of oriental fruit fly geographic populations and the genetic diversity between rearing populations and wild populations were discussed; analysed by MEGA and DnaSP software and combined with the geographical condition of Fujian. Genetic diversity among oriental fruit fly populations of Fujian , foreign populations and sibling species were also analyzed. A series of conclusions summarized as follows:32 haplotypes were identified based the mtDNA COI gene sequences. Every population had it own unique haplotypes. It indicated that genetic differences existed among populations, however, distribution of haplotypes was random and the gene flow of haplotypes was frequent. The result showed the degree of differences was not big. Oriental fruit fly populations of coastal areas had the smallest genetic differentiation and the Fst value between Xiamen and Quanzhou was the lowest. Analyzed with genetic differentiation index and genetic distance, Oriental fruit fly populations of mountain areas had the big genetic distance. The rearing populations had higher value of above indexes compared with wild populations.According to above results, the genetic differentiation within Fujian populations was small and the populations still kept closing genetic relationships among them. The genetic diversity between rearing populations and wild populations existed, but the most differentiation was within species. In the future, it is important to make quality control and rejuvenation during rearing in laboratory.Meanwhile, the analysis of oriental fruit fly populations with the rDNA-ITS1 gene sequences were performed based on Dnastar and DnaSP software. The identity of the rDNA-ITS1 gene among oriental fruit fly populations and its sibling species were over 94.6% and genetic distance value was 0.01. It showed that the genetic differences within oriental fruit fly populations and its sibling species was not obvious. This suggested that rDNA-ITS1 gene was not a good genetic marker for oriental fruit fly at infra-species and sibling species level.As the main member of Bacfrocera dorsalis complex, oriental fruit fly was closely connected with the complex. In this study, the molecular genetic marker identification and taxonomic studies of Bactrocera dorsalis complex were reviewed. It was helpful to apply the molecular approach to do taxonomic and phylogenetic analysis of the complex, The further research of oriental fruit fly , such as population differentiation, genetic study and evolution research, can be successfully made based on that.