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

9707372 McCauley本项目将研究Silene vulgaris（一种雌性雌雄异株植物）自然种群性别表达的遗传决定因素。在植物中，雌蕊异体，或在同一种群中存在雌性和雌雄同体的个体，是相当普遍的。雌雄同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。本研究将由两部分组成。首先，将进行一系列复杂的“测试”杂交，以表征细胞质和核基因位点的遗传多样性。其次，细胞质分子标记将被开发，使许多个体可以根据鉴定的雄性不育类型杂交分类。这将使人们能够迅速确定种群的遗传组成。对雌蕊异株物种经常观察到的一个现象是，雌性和雌雄同体的相对数量（性别比例）在不同的地方会发生巨大的变化。交叉和分子研究的一个目标是了解种群间性别比变化的遗传基础。这将是自然植物种群中为数不多的雌性雌蕊遗传学研究之一。利用雄性不育因子操纵重要经济作物的性别是植物育种的重要手段，但这一现象在自然界尚未得到很好的理解。除了对植物育种家有潜在的好处外，这项研究也将对基础群体遗传学领域有价值，因为它将有助于了解物种内遗传多样性是如何保持的。

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.