title: Phylogeographic patterns of Lygus pratensis (Hemiptera: Miridae): Evidence for weak genetic structure and recent expansion in northwest China.
abstract: Lygus pratensis (L.) is an important cotton pest in China, especially in the northwest region. Nymphs and adults cause serious quality and yield losses. However, the genetic structure and geographic distribution of L. pratensis is not well known. We analyzed genetic diversity, geographical structure, gene flow, and population dynamics of L. pratensis in northwest China using mitochondrial and nuclear sequence datasets to study phylogeographical patterns and demographic history. L. pratensis (n = 286) were collected at sites across an area spanning 2,180,000 km2, including the Xinjiang and Gansu-Ningxia regions. Populations in the two regions could be distinguished based on mitochondrial criteria but the overall genetic structure was weak. The nuclear dataset revealed a lack of diagnostic genetic structure across sample areas. Phylogenetic analysis indicated a lack of population level monophyly that may have been caused by incomplete lineage sorting. The Mantel test showed a significant correlation between genetic and geographic distances among the populations based on the mtDNA data. However the nuclear dataset did not show significant correlation. A high level of gene flow among populations was indicated by migration analysis; human activities may have also facilitated insect movement. The availability of irrigation water and ample cotton hosts makes the Xinjiang region well suited for L. pratensis reproduction. Bayesian skyline plot analysis, star-shaped network, and neutrality tests all indicated that L. pratensis has experienced recent population expansion. Climatic changes and extensive areas occupied by host plants have led to population expansion of L. pratensis. In conclusion, the present distribution and phylogeographic pattern of L. pratensis was influenced by climate, human activities, and availability of plant hosts.
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Zhang
authors.affiliation: Department of Entomology, China Agricultural University, Beijing, China.
authors.forename: Wan-Zhi
authors.initials: WZ
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Lv
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Xiang-Zhen
authors.initials: XZ
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, China.
authors.forename: Jin-Jie
authors.initials: JJ
authors.lastname: Cui
mesh_terms: D000818:Animals; D002681:China; D021901:DNA, Intergenic / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D051456:Gene Flow; D014644:Genetic Variation; D005828:Genetics, Population; D003368:Gossypium / Q000469:parasitology; D020062:Heteroptera / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics*; D058974:Phylogeography; D011157:Population Dynamics; D017422:Sequence Analysis, DNA
chemical_list: D021901:DNA, Intergenic; D004272:DNA, Mitochondrial; D004275:DNA, Ribosomal