Genetic diversity and structure in apple-infesting pests of Carposina sasakii, Grapholita dimorpha and Grapholita molesta in Korea

Abstract

The genetic diversity of three apple-infesting pests, Carposina sasakii, Grapholita dimorpha and Grapholita molesta, found in four local regions in Korea, was investigated using the mitochondrial cytochrome c oxidase I (COI) gene as a marker. Six, seven, and three larval haplotypes from C. sasakii, G. dimorpha, and G. molesta, respectively, were observed. The haplotype and nucleotide diversity were ranged as 0.31–0.69 and 0.0006–0.0040, respectively. The estimates of genetic differentiation (FST) among local populations in C. sasakii and G. dimorpha exhibited very narrow range differentiation as 0 to 0.025 and 0 to 0.075, respectively, whereas G. molesta revealed a moderate range of genetic distance (FST=0–0.461). In the AMOVA analysis, low percent variations (0–0.98%) and FST values (0 and 0.01, respectively) observed in C. sasakii and G. dimorpha, respectively, whereas G. molesta revealed moderate diversity as 31.3% (FST=0.313, p=0.038). These results would provide the basic information to understand the difference of genetic structure in species level and further be utilized to estimate the temporal and spatial distribution of these species in apple orchard.