Analysis of the genetic diversity in geographic populations of Leguminivora glycinivorella (Lepidoptera: Olethreutidae) from northeastern China based on mitochondrial DNA COI gene sequences.

【Aim】The soybean podborer,Leguminivora glycinivorella( Matsumura),is a major insect pest of soybean Glycina max,and it damages G. max seriously in northeastern China. This study aims to investigate the genetic differentiation among geographic populations of L. glycinivorella in northeastern China. 【Methods】A 657-bp segment of the mitochondrial cytochrome c oxidase subunit I( COI) gene of153 individuals from 10 geographic populations in northeastern China was sequenced and analyzed. The genetic diversity,gene flow and molecular variance were analyzed using DnaSP 5. 0 and Arlequin3. 5. 1. 2.【Results】The results showed that 36 variable sites were detected,and 17 haplotypes were defined based on the COI sequences of 10 geographic populations of L. glycinivorella,including one haplotype shared by all the 10 populations. The total haplotype diversity of all populations was 0. 456,and the range of haplotype diversity of different populations was 0- 0. 634. The total Fst,Gst and Nm were 0. 12545,0. 06326 and 3. 49,respectively,and all pairwise gene flow Nm was greater than 1 in the10 populations, suggesting that extensive gene flow occurred among the ten populations of L.glycinivorella. 【Conclusion】The L. glycinivorella populations are characterized by medium /low genetic diversity. The Tajima's D test indicated that there might not have been a recent population expansion.Molecular variance analysis( AMOVA) demonstrated that the observed genetic differentiation occurs primarily within populations,and there is no obvious genetic differentiation among populations. The neighbor-joining phylogenetic tree and haplotype network showed that the haplotypes are distributed in different clades and no obvious geographical structure has been formed. The genetic distance is not significantly correlated with the geographical distance between populations,and the gene flow is not affected by geographical distance.