Genetic Basis of Gender Expression in Silene vulgaris, a Gynodioecious plant

9707372麦考利这个项目将调查雌雄异株植物--普通硅藻--自然种群中性别表达的遗传决定因素。在植物中，雌雄异株，即在同一种群中存在雌性和两性个体是相当常见的。雌雄异株植物的性别决定通常是细胞质中消除雄性功能的基因和细胞核中恢复雄性功能的基因相互作用的结果。对普通链霉菌的研究将由两部分组成。首先，将进行一系列复杂的“测试器”杂交，以表征细胞质和核基因座的遗传多样性。其次，将开发细胞质分子标记，以便根据杂交鉴定的雄性不育类型对众多个体进行分类。这将使快速确定种群的遗传构成成为可能。一个经常由雌雄异株物种组成的观察结果是，雌性和两性的相对数量(性别比例)在不同的地方可能会有很大的差异。杂交和分子研究的目标之一是了解种群与种群性别比变异的遗传基础。这将是为数不多的关于自然植物种群雌雄异株遗传学的研究之一。利用雄性不育因子来控制具有重要经济价值的作物的性别是植物育种中的一个重要工具，但这一现象在自然界中还没有得到很好的理解。除了对植物育种者的潜在好处外，这项研究还将对基础种群遗传学领域有价值，因为它将有助于理解物种内如何保持遗传多样性。

9707372 McCauley This project will investigate the genetic determinants of sex expression in natural populations of Silene vulgaris, a gynodioecious plant. In plants gynodioecy, or the presence of female and hermaphroditic individuals in the same population, is fairly common. Sex determination in gynodioecious plants is often a consequence of the interaction of genes in the cytoplasm that eliminate male function, and genes in the nucleus that restore it. The study of S. vulgaris will consist of two parts. First, a complex series of "tester" crosses will be conducted in order to characterize genetic diversity at the cytoplasmic and nuclear gene loci. Second, cytoplasmic molecular markers will be developed so that numerous individuals can be classified according to the male sterility types identified by the crosses. This will enable a rapid characterization of the genetic composition of populations. One observation that is often made of gynodioecious species is that the relative numbers of females and hermaphrodites (the sex ratio) can vary dramatically from place to place. One goal of the crosses and molecular studies is to understand the genetic basis for population to population variation in the sex ratio. This will be one of just a few investigations of the genetics of gynodioecy in natural plant populations. The use of male sterility factors to manipulate the gender of economically important crop plants is an important tool in plant breeding, yet the phenomenon is not well understood in nature. In addition to potential benefits to plant breeders, this study will also be of value to the field of basic population genetics, in that it will contribute to an understanding of how genetic diversity is maintained within species.