Population genetics of Liriomyza trifolii (Diptera: Agromyzidae) and comparison with four Liriomyza species in China based on COI, EF-1a and microsatellites loci

Abstract

AbstractLiriomyzais a large genus that includes polyphagous and invasive species (L. trifolii, L. sativae, andL. huidobrensis), and oligophagous species such asL. Chinensisin China. Effective control of these invasive and oligophagous species is not easy due to the fast invasion rate, interspecific competition, and pesticide resistance. In this study, we investigated population genetics of fiveLiriomyzaspeciesL. trifolii, L. sativae, L. huidobrensis, L. bryoniae, andL. chinensisbased onCOIandEF-1agenes, and microsatellite DNA. These fiveLiriomyzaspecies revealed highly conservative characteristics in theCOIgene among populations collected from different geographical regions and host plants. By contrast, the mutation rate of theEF-1agene was higher thanCOI, and phylogenetic tree based onEF-1ashowed that haplotypes ofL. trifoliiandL. sativaewere not distinguished well. Genetic differentiation in microsatellite loci was obvious among the five species. Our results also indicated that geographic isolation had a greater impact on genetic differentiation inL. trifoliithan the host plant. Populations ofL. trifoliiin China showed a high to moderate level of genetic differentiation and they had divided into two groups representing the coastal areas of southern China and northern regions. The genetic diversity of the southern group was higher than the northern group. We speculated that the invasion ofL. trifoliilikely occurred in southern regions of China and then spread northward. Bottleneck analyses revealed that theL. trifoliipopulation in China was in a steady growth period.