Dissertation Research: Polyploid in Tragopogon: Multiple Origins and Mating System Diversification

小行星9624643 自然界中新物种的出现是一件大事。植物界中的新物种可能以多种方式出现，其中之一是通过两个不同物种的杂交（杂交育种）和多倍化（染色体加倍）的组合过程。 其结果是一个新的，遗传上独特的“多倍体”物种，其染色体数量是其祖先的两倍。 该奖项资助的研究解决了关于这一过程的两个主要问题：（1）相对年轻的多倍体物种的交配系统是否与亲本物种的交配系统不同？(2)这种杂交和多倍化事件的结合在每个物种中发生过不止一次吗？如果是的话，发生的频率是多少？ 该研究利用了一个模式系统的植物进化研究，属婆罗门参（菊科）。 在过去的60年里，在太平洋西北部的帕卢塞地区，这种类型的物种形成发生了两次。了解这一过程可以为物种如何产生以及物种起源后不久发生的事情提供新的见解。 因为同样的杂交和多倍化事件描述了我们一些最重要的作物的历史（例如，小麦），关于这一进化途径的信息对通过育种和基因工程进行作物改良具有意义。

9624643 Soltis The appearance of new species in nature is an important event. New species may arise in the plant kingdom in a number of ways, one of which is through the combined processes of hybridization (cross-breeding) of two different species, and polyploidization (chromosome doubling). The result is a new, genetically distinct "polyploid" species that has twice the number of chromosomes as its progenitors. Research funded by this award addresses two main questions about this process: (1) Have the mating systems of the relatively young polyploid species diverged from mating systems of the parental species? (2) Has this combination of hybridization and polyploidization events occurred more than once in each species, and if so, how often? The research utilizes a model system for the study of plant evolution, the genus Tragopogon (Asteraceae). In Tragopogon, this type of species formation has occurred twice in the Palouse Region of the Pacific Northwest within the last 60 years. Understanding this process can provide new insights into how species can arise and what happens shortly after a species' origin. Because the same events of hybridization and polyploidization characterize the histories of some of our most important crops (e.g., wheat), information on this evolutionary pathway has implications for crop improvement through breeding and genetic engineering.