The Genetic Architecture of Specialization and Isolation Between Divergent Populations

9629081产生生物多样性的一个基本过程是物种形成，即一个物种的种群分化并最终成为独立的物种。导致种群分化和物种形成的基因变化鲜为人知。该项目的目标是确定影响豌豆蚜虫这一寄生在两种寄主植物上的单一昆虫种群之间差异的基因的数量和影响。苜蓿和三叶草上的豌豆蚜虫种群具有高度的遗传差异，并且由于栖息地的选择而显著隔离，因此似乎是早期物种。利用分子连锁图谱分析和生物计量学分析，将影响寄主植物选择和寄主植物存活和育性的数量性状位点（qtl）定位到染色体上。研究物种形成的遗传基础是了解物种生物多样性产生的基础。这也有助于了解害虫如何适应新的宿主，以及相关害虫物种之间有多少基因流动。

9629081 Via A basic process generating biological diversity is speciation, when populations of one species diverge and eventually become separate species. The genetic changes that produce population divergence and speciation are poorly known. The goal of this project is to determine the number and effects of genes that influence divergence between populations of a single insect species, pea aphid, that infests two host plants. Pea aphid populations on alfalfa and clover are highly genetically divergent and significantly isolated due to habitat choice, and so appear to be incipient species. Quantitative trait loci (QTLs) influencing host plant choice and survival and fertility on each host plant will be mapped on chromosomes using molecular linkage map analysis, as well as biometrical analyses. Studying the genetic basis for speciation is fundamental for understanding the generation of species biodiversity. It is also useful for understanding how pests adapt to new hosts, and how much gene flow there can be between related pest species.