Fig. 4. Migration rate among four group, between species.
According to the method of EVANNO, a maximum likelihood (∆K ) was used to determine the value of K . In this study, when K =2,∆K reached the maximum value (Fig. 5). The four groups were divided into two species. Unexpected, the potential K value for the OLb group was not 2 but 4. Mixed individuals were found between and within the four groups, indicating that there have gene flow among groups and species.