Dissertation Research: A Molecular Examination of Homoploid Hybrid Speciation in Penstemon

杂交在新物种形成中的作用， 特别是在二倍体水平上， 进化研究生Andrea Wolfe，在 俄克拉荷马州大学的指导教师韦恩·埃里森斯建议， 为了检验各种关于同倍体杂种物种形成的假设， 四种多年生草本植物的复合体 用分子和遗传标记进行的。个体植物 将在每个物种的整个范围内取样， 同工酶（蛋白质）变异和突变差异 叶绿体DNA和核核糖体DNA。因为这些数据 提供遗传标记， 中介性和支配性，它们特别适合于 测试关于杂交和基因渗入的假设， 新物种起源于稳定的杂交重组体。的 这项研究是一个独特的机会，以测试两个例子， 在一组密切相关的植物中的杂交物种形成。因为 一个所谓的亲本物种，Penstemon centranthifolius， 许多诊断分子和遗传标记， 它从这个杂交复合体的其他成员中分离出来， 还提供了一个很好的系统来测试渐渗模型， 杂交，基因从一个物种“泄漏”到 另

The role of hybridization in the formation of new species, particularly at the diploid level, is a central problem of plant evolution. Graduate student Andrea Wolfe, under the direction of faculty advisor Wayne Elisens at University of Oklahoma, proposes to test various hypotheses of homoploid hybrid speciation in a complex of four species of herbaceous perennials in the genus Penstemon, using molecular and genetic markers. Individual plants sampled throughout the range of each species will be surveyed for isozyme (protein) variation and for mutational differences in chloroplast DNA and in nuclear ribosomal DNA. Because these data provide genetic markers which minimize problems of character intermediacy and dominance, they are especially appropriate for testing hypotheses about hybridization and introgression, and the origin of new species from stabilized hybrid recombinants. The study represents a unique opportunity to test two examples of hybrid speciation in a group of closely related plants. Because one purported parental species, Penstemon centranthifolius, has numerous diagnostic molecular and genetic markers which distinguish it from other members of this hybrid complex, the group of species also offers an excellent system to test models of introgressive hybridization, the "leakage" of genes from one species into another.