Population Genetic Diversity Of Host Plants Of Rhus Gall Aphid In North America

Chinese gallnut aphid is parasitic on plant Rhus.Rhus gall aphids include six genera 12 species,which are distributed in Eastern Asia and North America and mainly in China.5 genera and 11 species.In North America,there is only species Melaphis rhois,Whose host plants are two species Rhus glabra and Rhus typhina,(Sapindales,Anacardiaceae).Rhus species belong to small deciduous trees native to North America,and they are widely used in medicine,planting.As the special host plants of Rhus gall aphids in North America,there is no reports on the genetic diversity.In this study,we performed the genetic diversity analysis of the host plants Rhus typhina and Rhus glabra of Rhus gall aphis Melaphis rhois in North America inferring from three chloroplast genes and one nuclear gene.The main results are as following:We obtained the concatenated cpDNA(TrnL-TrnF?PsbA and rbcL),sequences 2764 bp in length,whichinclude 2715 Conserved sites and 49 Variable sites;Rhus glabra have sequences 2755 bp,with 2740 conserved sites and 15 variable sites.Then ITS region sequences of Rhus typhina contained 615 Conserved sites and 29 Variable sites,Rhus glabra cover630 conserved sites and 14 variable sites.Comparison between the two,the variable sites number of Rhus typhina is higher than Rhus glabra.1)Nine haplotypes were identified in cpDNA sequences in Rhus typhina,the haplotype diversity and nucleotide diversity were0.64802±0.056 and 0.00142±0.00023,respectively;six haplotypes were detected in cpDNA sequences in Rhus glabra,the haplotype diversity and nucleotide diversity were 0.34188±0.117 and 0.00051±0.00020,respectively;2)Twenty-seven haplotypes were identified in ITS sequences in Rhus typhina,the haplotype diversity and nucleotide diversity were0.92801±0.023 and 0.00505±0.00048,respectively;Twenty haplotypes were detected in ITS sequences in Rhus glabra,the haplotypediversity and nucleotide diversity were 0.97846±0.017 and0.00581±0.00055,respectively;The data analysis showed that Rhus glabra has higher than Rhus typhina in gene diversity.3)Analysis of molecular variance(AMOVA)showed that the genetic variation within populations was much higher than among populations both in Rhus typhina and Rhus glabra.4)The Fixation Index(Fst)from Rhus typhina based on cpDNA sequences was 0.08396,the Fst based on ITS squences was 0.08981,compared with Rhus glabra,the Fst of Rhus typhina was higher both based on cpDNA sequences and ITS squences.5)The TCS network of Rhus typhina and Rhus glabra show that the haplotypes present a cross distribution,which present a close relationship between them.