Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, People's Republic of China.
School of Biological Sciences, The University of Queensland, Brisbane, Australia.
Pest Manag Sci. 2020 Feb;76(2):695-703. doi: 10.1002/ps.5567. Epub 2019 Aug 27.
The rice stem borer, Chilo suppressalis, is a serious pest of rice, but also damages an aquatic vegetable, water oats (Zizania latifolia Turcz.). The time at which mating occurs is different between populations of rice stem borer associated with rice and those associated with water-oats, which suggests that undetected cryptic species may be associated with these plant hosts. If true, this would have significant management implications. This study is the first empirical test of this idea, using population genetic tools from two sampling cohorts. We genotyped 320 rice stem borer individuals from 2014, collected from rice and water-oats across five locations (where they exist in sympatry), using seven microsatellite loci.
We found no genetic structuring associated with host plant species. On water oats, some rice stem borers were found that had a similar mating time to the rice population, so in 2016, a second cohort of samples was screened by their timing of mating to get 'pure rice feeders' and 'pure water oats feeders'. These samples were genotyped with microsatellites, mitochondrial DNA (mtDNA) (COI and COII), and a nuclear gene (EF1-α). Our mtDNA data suggest a relatively low amount of population subdivision associated with plant host, but the microsatellite data revealed no such genetic structure, and we were only able to identify one haplotype of EF1-α.
Our results indicate gene flow between rice and water oats populations of rice stem borer, indicating that water oats will likely provide a refuge for resistance management of Bt rice. © 2019 Society of Chemical Industry.
二化螟是水稻的严重害虫，但也会损害水生蔬菜茭白。与水稻相关的二化螟种群与与茭白相关的种群的交配时间不同，这表明可能存在与这些植物宿主相关的未被发现的隐种。如果是这样，这将具有重要的管理意义。本研究首次使用来自两个抽样队列的种群遗传工具对此想法进行了实证检验。我们使用 7 个微卫星标记对来自 2014 年的来自水稻和茭白的 20 个地点（它们在同域共存）的 320 个二化螟个体进行了基因分型。
我们没有发现与宿主植物物种相关的遗传结构。在茭白上，发现了一些与水稻种群交配时间相似的二化螟，因此在 2016 年，通过交配时间对第二批样本进行了筛选，以获得“纯水稻饲养者”和“纯茭白饲养者”。这些样本用微卫星、线粒体 DNA（COI 和 COII）和核基因（EF1-α）进行了基因分型。我们的 mtDNA 数据表明与植物宿主相关的种群细分程度相对较低，但微卫星数据没有显示出这种遗传结构，我们只能识别出 EF1-α 的一个单倍型。
我们的结果表明水稻和茭白种群的二化螟之间存在基因流，这表明茭白可能为 Bt 水稻的抗性管理提供避难所。© 2019 化学工业学会。
