Population genetics and demographic history of guava fruit fly Bactrocera correcta (Diptera: Tephritidae) in northeastern Thailand

摘要

Bactrocera correcta (Bezzi) is among the most destructive fruit fly pests of the genus Bactrocera. This species infests 62 species of plants belonging 30 families, many of which are commercially important. In this study, the genetic structure, diversity and demographic history of B. correcta in Thailand were inferred from mitochondrial cytochrome c oxidase I (COI) sequences. High genetic diversity was recorded in the 171 samples collected from 15 locations. This was due largely to the existence of two divergent lineages (I, II) revealed by median joining (MJ) network analysis. Genetic structure analysis revealed an overall low level of genetic differentiation between populations suggesting that the flies can move freely across geographic regions. Because the host plants are commonly grown in Thailand, continuity of habitats is the factor most likely responsible for the genetic homogeneity. In addition, the recent population history could also be a factor that contributed to the overall low level of the genetic structure. Mismatch distribution analysis as well as Tajima's D and Fu's F-S tests detected evidence of recent demographic expansion dating back to the end of the last glaciations.