Sexual dimorphism in the dioecious grass Distichlis spicata: testing hypotheses for the evolution of intraspecific niche divergence

在不能移动的生物体中，雄性和雌性在空间上的分离应该是一个显著的劣势。然而，空间分离在不同性别的植物中很常见。这个项目将结合田野、温室和分子方法，严格测试湿地草二刺草(盐草)性别空间分离的机制。这项研究利用新的分子技术来识别盐草幼苗是雄性还是雌性，然后在一套综合的实验中跟踪两性的命运，这些实验将评估同一物种的雄性和雌性在不同的栖息地争夺有限资源的机制和后果。此外，这些实验将测试土壤生物群是否在雄性和雌性不同的植物-土壤联合中发挥重要作用。这项拟议的研究将对湿地保护、资源管理和学生培训产生重大影响。预计在可预见的未来，海平面将会上升。了解盐草的雄株和雌株是如何竞争的，将使研究人员能够预测海平面上升对这种重要的盐沼物种的影响。该研究还具有一定的应用价值，因为盐草及其相关物种在农艺和环境恢复方面具有重要的应用价值。该项目还将为两名研究生和12名本科生提供支持。本科生将通过与当地社区大学的外联活动来招聘，以通过有针对性的实习来增加对代表性不足群体的招聘。

PROJECT ABSTRACTSpatial separation of males and females should be a significant disadvantage in organisms that are not mobile. However, spatial separation is common in plants with separate sexes. This project will integrate field, greenhouse, and molecular approaches to rigorously test hypotheses for mechanisms causing spatial separation of the sexes in the wetland grass Distichlis spicata (saltgrass). The study takes advantage of novel molecular techniques to identify saltgrass seedlings as male or female, then follows the fates of both genders in an integrated set of experiments that will evaluate the mechanisms and consequences of competition for limited resources by males and females of the same species in a variety of habitats. Additionally, the experiments will test whether the soil biota plays a significant role in the different plant-soil associations of males and females. The proposed research will have significant impacts on wetland conservation, resource management, and student training. Sea levels are projected to rise for the foreseeable future. Understanding how male and female plants of saltgrass compete will allow researchers to anticipate the effects of rising sea levels on this important salt marsh species. The proposed research also has applied value, because saltgrass and related species are used in agronomy and environmental restoration. The project will also provide support for two graduate and 12 undergraduate students. Undergraduates will be recruited through outreach to local community colleges to increase recruitment of underrepresented groups via targeted internships.