Evolution of Species' Differences in Annual Sunflowers

农业、医学、进化和生态中最重要的特征都有复杂的遗传基础。最近在估计控制这些性状的基因数量和单个基因的影响方面取得了重大进展。然而，为了理解物种之间的性状差异是如何形成的，这些基因对生存能力和生殖产出（即适应性）的影响必须在自然种群中确定。在这个提议中，遗传学和生态学的方法将被用来估计八个基因（或包含它们的小染色体片段）的适应度效应，这些基因控制着两个向日葵物种之间的差异。这些估计的有效性将通过分析两个物种在自然杂交时这些基因的运动来验证。预计拟议的活动将通过对代表性不足的群体、本科生和研究生以及博士后学者的研究培训产生更广泛的影响。此外，在这笔拨款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。

The most important traits in agriculture, medicine, evolution, and ecology have a complex genetic basis. Significant progress has been made recently toward estimating the number of genes that control these traits and the effects of individual genes. To understand how trait differences become established between species, however, the effects of these genes on viability and reproductive output (i.e., fitness) must be determined in natural populations. In this proposal, both genetic and ecological approaches will be employed to estimate the fitness effects of eight genes (or small chromosomal segments that contain them) that control differences between two sunflower species. The validity of these estimates will be verified by analyzing the movement of these genes between the two species when they hybridize in nature.The proposed activities are anticipated to have broader impacts through research training of underrepresented groups, undergraduate and graduate students, and postdoctoral scholars. In addition, 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.