DISSERTATION RESEARCH: Interrelationships Among Perianth Size, Inbreeding, and Divergence in the Plant Boerhavia (Nyctaginaceae)

这项研究涉及一组大约22种植物，它们在索诺兰和奇瓦瓦沙漠中多样化，属于Boerhavia属。Boerhavia的物种可以自花授粉，而且花的大小也非常不同，这影响了昆虫访问植物和在植物之间传递花粉的频率。这个项目测试花较小的物种是否在高度近亲繁殖的种群之间有更大的遗传分化，因为花粉不能经常在种群之间流动。基因指纹技术将确定一株植物上由其他个体繁殖的种子的比例。这将适用于每个种群的许多个体，适用于所有北美物种。同样的数据还将提供种群之间的差异及其近亲繁殖水平的估计。将这些数据与Boerhavia的进化史相结合，将有可能测试花较小的物种是否表现出分化为遗传上不同的物种的种群。该项目将为N.Douglas提供植物学和种群生物学方面的培训。墨西哥植物学家正在合作进行这项研究。该项目将估计美国和墨西哥四个极其稀有、未受保护的物种的总遗传多样性。因此，它将在两国的植物学家、生态学家和自然资源保护者中找到观众。

This research concerns a group of approximately 22 plant species that has diversified in the Sonoran and Chihuahuan Deserts, the genus Boerhavia. Species of Boerhavia can self-pollinate, and also have very different flower sizes, which affects how often insects visit and transfer pollen between plants. This project tests whether species with smaller flowers have a greater amount of genetic differentiation between populations that are highly inbred, because pollen can not frequently flow between populations. Genetic fingerprinting techniques will establish the proportion of seeds on a plant that are sired by other individuals. This will be done for many individuals per population, for all North American species. The same data will also provide estimates of the differences between populations, and their level of inbreeding. Combining this data with the evolutionary history of Boerhavia, it will be possible to test whether species with smaller flowers exhibit populations diverging into genetically distinct species.This project will provide training for N. Douglas in botany and population biology. Mexican botanists are collaborating in this research. The project will estimate the total genetic diversity of four extremely rare, unprotected species in the U.S. and Mexico. Thus, it will find an audience among botanists, ecologists, and conservationists in both nations.