The Influence of Hybridization and Polyploidy on Speciation in Houstonia

了解地球上物种多样性的起源仍然是一个难题。 在植物中，很明显，这种多样性的大部分是由于物种的染色体加倍（多倍性）以及物种之间的杂交。然而，目前还不清楚这两个过程如何在新物种的进化中相互作用。该项目将测试的假设，即多倍体增加物种之间的杂交率相对于nonpolyploids使用一组密切相关的本地植物物种（Houstonia）作为研究系统。将使用细胞学技术确定这些物种的自然种群的染色体数目。分子标记将用于评估不同染色体数目物种之间的历史杂交率。这项研究的结果将增强我们对多倍体和杂交的理解，这是植物物种形成的两种最重要的模式。我们许多最重要的作物物种要么是多倍体，要么是杂交种，或者两者兼而有之，包括玉米、棉花和小麦，因此了解杂交和多倍体之间的相互作用也可以加强农业育种计划。这项研究将培养本科生和研究生的生物学研究方法，让他们有机会参与数据收集，管理和分析，并进行独立的研究。

Understanding the origins of the diversity of species on earth remains a difficult question. In plants, it is apparent that much of this diversity is due to both doubling of the chromosomes of species (polyploidy) as well as hybridization among species. However, it remains unclear how these two processes interact in the evolution of new species. This project will test the hypothesis that polyploidy increases rates of hybridization among species relative to nonpolyploids using a group of closely related native plant species (Houstonia) as the study system. Chromosome numbers of natural populations of these species will be determined using cytological techniques. Molecular markers will then be used to assess the historical rate of hybridization among species with varying chromosome numbers. The results of this research will enhance our understanding of polyploidy and hybridization, two of the most important modes of speciation in plants. Many of our most important crop species are either polyploids or hybrids, or both, including corn, cotton, and wheat, so understanding the interaction between hybridization and polyploidy could enhance agricultural breeding programs as well. This research will train both undergraduate and graduate students in biological research methods by giving them an opportunity to participate in data collection, management, and analysis, and conducting independent research.