DISSERTATION RESEARCH: Adaptive Trait Introgression in Helianthus

有效的杂草管理需要了解植物入侵的一般机制。本研究将探讨通过性杂交（即基因渗入）的种间基因流动作为向日葵入侵背后的机制。据推测，普通杂草向日葵（Helianthus annuus）是通过获得德克萨斯州本土植物H. debuis的基因而在德克萨斯州定居的。为了验证这一假设，a)两个物种之间的杂交将在德克萨斯州种植，以确定在自然界中赋予优势的性状；b)这些性状的潜在基因将被绘制出来；c)在德克萨斯州黄杨（ssp.）自然种群中，黄杨衍生基因的频率。德克萨斯州)将被分析。拟议的实验将有助于回答一个长期存在的问题，即入侵分类群的起源中渗入的作用，并将允许识别使杂草向日葵入侵的特定特征/基因。在这项资助中创建的遗传材料将免费提供给其他研究人员。向日葵是美国唯一驯化的主要作物植物，所选择的研究性状对野生向日葵物种的多样化以及栽培向日葵的驯化和持续改进都具有重要意义。这项研究还将促进对年轻妇女和少数民族科学家的培训。

Effective weed management requires an understanding of the general mechanisms underlying plant invasiveness. The proposed research will investigate interspecific gene flow through sexual hybridization (i.e., introgression) as a mechanism behind invasiveness in sunflowers. The common weed sunflower (Helianthus annuus) is postulated to have colonized Texas by acquiring genes from a Texas native, H. debilis. To evaluate this hypothesis, a) hybrids between the two species will be planted in Texas to identify traits conferring advantages in nature, b) genes underlying these traits will be mapped, and c) the frequencies of H. debilis-derived genes in natural populations of Texan H. annuus (ssp. texanus) will be assayed. The proposed experiments will help to answer a long-standing question about the role of introgression in the origin of invasive taxa, and will also allow identification of the particular trait(s)/genes that enable invasions by weedy sunflowers. The genetic materials created in this grant will be made freely available to other researchers. Sunflower is the only major crop plant domesticated in the U.S., and the traits chosen for study are important both to the diversification of wild sunflower species and to the domestication and continued improvement of the cultivated sunflower. This research will also facilitate the training of young women and minority scientists.