Analysis Of The Genetic Diversity And Gene Flow In Geographic Populations Of Leguminivora Glycinivorella (Lepidoptera: Olethreutidae) In Northeastern China

The Leguminivora glycinivorella have only one generation in every year, a long-time diapause, and weaker flight ability. Thus long-time geographic isolation could lead to genetic variation of L. glycinivorella populations, and increase the difficulties for it’s prevention and control. Threrfore, it’s reasonable and important to clarify the genetic structure variation and genetic diversity of L. glycinivorella populations hosting on soybean in China, analyze it’s relative relationship between every geographic populations and know the regular of demographic history in population expansion are important to manage this pest.In this study, using three frequently-used mitochondrial genes(mtDNA), the populations of L. glycinivorella hosting on soybean from 10 localities in the northeastern China were studied and analysed. The main results of study were as follows:(1) Sequences of these three mtDNA genes(CO I,CO II and Cytb)were obtained respectively by PCR from 490 individuals of L. glycinivorella from 10 localities in the northeastern China. The length of three mtDNA genes are 657 bp, 683 bp and 415 bp. Based on 3 gene sequences, 17 haplotypes of COI gene, 16 haplotypes of CO II gene and 14 haplotypes of Cytb gene were observed.(2)The percentage of COI sequences, CO II sequences and Cytb sequences polymorphic sites were 5.48%, 4.83% and 7.71%; the values of haplotype diversity(Hd) were 0.456, 0.463 and 0.443 respectively; And the values of nucleic diversity(π) were 0.00676, 0.00170 and 0.01143 respectively. The Tajima’s D and Fu’s Fs test indicated that there might not have been a recent population expansion in its history of evolution, L. glycinivorella populations are characterized by medium/low haplotype diversity and nucleotide diversity, resulting in no significant genetic differentiation and Low genetic diversity level occurred among populations.(3) Phylogenetic trees and haplotype networks did not reflect geographical position, indicating a lack of obvious geographic structure, and haplotypes were not clustered according to geographic population distribution.(4)Genetic differentiation of L. glycinivorella populations in northeastern China occurred primarily within populations, whereas the genetic variation among populations was relatively low. The Nm for all groups was greater than one, suggesting that the higher level of gene flow among populations.(5) Mantel test showed no significant linear dependence between genetic distance and geographic distance, suggesting that temporary reproductive and geographic isolation did not act as a barrier for gene flow, and genetic variation is not influenced by geographic distance.