Franklin Michelle T, Ritland Carol E, Myers Judith H
Department of Zoology, University of British Columbia Vancouver, BC, Canada.
Department of Forest Sciences, Genetic Data Centre, University of British Columbia Vancouver, BC, Canada.
Evol Appl. 2011 Jan;4(1):89-99. doi: 10.1111/j.1752-4571.2010.00135.x. Epub 2010 Jun 8.
Long-range migrations of many wind-borne noctuid moths will have been influenced by the expansion of agriculture that provides greater availability of food plants along the migratory route. The migratory, agricultural pest, Trichoplusia ni (cabbage looper) over-winters in southern California and each summer migrates as far north as British Columbia. We explored the degree of genetic connectivity of populations over this migratory range. Preliminary investigation of seven mitochondrial gene regions found little to no variation among 13 populations, while partial regions of the NADH dehydrogenase subunits 1 and 4 in 42 individuals revealed eight and six haplotypes, respectively. The pattern of haplotype distribution indicated genetic homogeneity of persistent populations in California but weak differentiation among populations further north. Four highly variable amplified fragment length polymorphism primer combinations generated 167 polymorphic bands, with heterozygosity levels ranging from 0.250 to 0.302. Pairwise F ST values and clustering analyses also showed similarty among populations in California with some differentiation among populations initiated from the annual migration. Overall, some differentiation occurs among temporary, annual migratory populations but no pattern occurs with distance from the source population. Population subdivision in British Columbia associated with greenhouses has the greatest impact on genetic differentiation.
许多随风迁徙的夜蛾的远距离迁徙可能受到了农业扩张的影响，农业扩张使得迁徙路线沿线的食草植物更容易获取。迁徙性农业害虫粉纹夜蛾（甘蓝夜蛾）在加利福尼亚州南部越冬，每年夏天向北迁徙至不列颠哥伦比亚省。我们探究了该迁徙范围内种群的遗传连通程度。对七个线粒体基因区域的初步调查发现，13个种群之间几乎没有或根本没有变异，而对42个个体的NADH脱氢酶亚基1和4的部分区域分析分别发现了8种和6种单倍型。单倍型分布模式表明，加利福尼亚州的持续种群具有遗传同质性，但更北部的种群之间存在微弱分化。四种高度可变的扩增片段长度多态性引物组合产生了167条多态性条带，杂合度水平在0.250至0.302之间。成对F ST值和聚类分析也表明，加利福尼亚州的种群之间具有相似性，而每年迁徙产生的种群之间存在一些分化。总体而言，临时的、每年迁徙的种群之间存在一些分化，但与源种群的距离没有呈现出特定模式。不列颠哥伦比亚省与温室相关的种群细分对遗传分化的影响最大。
