title: Detecting deep divergence in seventeen populations of tea geometrid (Ectropis obliqua Prout) in China by COI mtDNA and cross-breeding.
abstract: The tea geometrid (Ectropis obliqua Prout, Lepidoptera: Geometridae) is a dominant chewing insect endemic in most tea-growing areas in China. Recently some E. obliqua populations have been found to be resistant to the nucleopolyhedrovirus (EoNPV), a host-specific virus that has so far been found only in E. obliqua. Although the resistant populations are morphologically indistinguishable from susceptible populations, we conducted a nationwide collection and examined the genetic divergence in the COI region of the mtDNA in E. obliqua. Phylogenetic analyses of mtDNA in 17 populations revealed two divergent clades with genetic distance greater than 3.7% between clades and less than 0.7% within clades. Therefore, we suggest that E. obliqua falls into two distinct groups. Further inheritance analyses using reciprocal single-pair mating showed an abnormal F₁ generation with an unbalanced sex ratio and the inability to produce fertile eggs (or any eggs) through F1 self-crossing. These data revealed a potential cryptic species complex with deep divergence and reproductive isolation within E. obliqua. Uneven distribution of the groups suggests a possible geographic effect on the divergence. Future investigations will be conducted to examine whether EoNPV selection or other factors prompted the evolution of resistance.
authors.affiliation: Key Laboratory of Tea Plants Biology and Resources Utilization of Agriculture Ministry, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
authors.forename: Gui-Hua
authors.initials: GH
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tea Plants Biology and Resources Utilization of Agriculture Ministry, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Yuan
authors.affiliation: Institute of Insect Science, Zhejiang University, Hangzhou, China.
authors.forename: Chuan-Xi
authors.initials: CX
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tea Plants Biology and Resources Utilization of Agriculture Ministry, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
authors.forename: Kun-Shan
authors.initials: KS
authors.lastname: Yin
authors.affiliation: Key Laboratory of Tea Plants Biology and Resources Utilization of Agriculture Ministry, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
authors.forename: Mei-Jun
authors.initials: MJ
authors.lastname: Tang
authors.affiliation: Key Laboratory of Tea Plants Biology and Resources Utilization of Agriculture Ministry, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
authors.forename: Hua-Wei
authors.initials: HW
authors.lastname: Guo
authors.affiliation: Key Laboratory of Tea Plants Biology and Resources Utilization of Agriculture Ministry, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
authors.forename: Jian-Yu
authors.initials: JY
authors.lastname: Fu
authors.affiliation: Key Laboratory of Tea Plants Biology and Resources Utilization of Agriculture Ministry, Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xiao
mesh_terms: D000818:Animals; D001947:Breeding; D002681:China; D003433:Crosses, Genetic; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D014644:Genetic Variation; D005843:Geography; D040582:Inheritance Patterns / Q000235:genetics; D007915:Lepidoptera / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011157:Population Dynamics; D017422:Sequence Analysis, DNA; D013662:Tea / Q000469:parasitology*
chemical_list: D004272:DNA, Mitochondrial; D013662:Tea; D003576:Electron Transport Complex IV