\Genetics of differences in host range of a generalist and specialist herbivore

9981671 GouldAnimal物种符合从利用广泛食物和栖息地的通才到有非常特殊要求的专家的连续统一体。一些以植物为食的昆虫可以成功地吃掉数百种不同植物的叶子，但这些昆虫大多专门捕食一到几种植物。相比之下，大多数毁灭性的农作物害虫都是多面手。其中一种名为Heliothis greresens，是一种主要的棉花害虫，但也以西红柿、大豆、烟草和其他非农业植物为食。这是一个极端的专家，只捕食一些种类的酸浆(中国灯笼植物)。这两种昆虫可以杂交，后代回交给专家。基因分离的回交后代的特化程度各不相同。分子基因图谱技术，扩增片段长度多态性，将被用来确定这些杂交后代中的哪些基因使它们能够吃掉多面手物种的食用植物。从这项遗传图谱研究中获得的信息将被用来研究基因如何相互作用来确定一个物种的生态位，并可能为降低害虫的遗传潜力提供工具。

9981671GouldAnimal species fit along a continuum from generalists, which utilize a broad array of foods and habitats, to specialists, which have very specific requirements. Some plant-feeding insects can successfully consume leaves from hundreds of diverse plant species, but most of these insects specialize on one to a few plant species. In contrast, the majority of devastating crop pests are generalists. One of these, Heliothis virescens, is a major cotton pest but also feeds on tomatoes, soybean, tobacco and other non-agricultural plants. Heliothis subflexa is closely related to H. virescens but is an extreme specialists, only feeding on some species of Physalis (Chinese lantern plant). These two insect species can be hybridized and the offspring backcrossed to the specialist. The genetically segregating backcross offspring vary in degree of specialization. A molecular gene mapping technique, Amplified Fragment Length Polymorphism, will be used to determine which genes in these hybrid offspring enable them to consume the generalist species food plants. Information gained from this genetic mapping research will be used to examine how genes interact in determining the ecological niche of a species, and could provide tools for decreasing the genetic potency of pests.