Collaborative Research: Unraveling the Dynamics of Mating System Evolution in the Tribe Collinsieae (Scrophulariaceae)

本研究解决了有关植物交配系统进化的基本问题：（1）自花授粉为什么会进化？(2)自我繁殖是进化的死胡同吗？(3)自交与远系繁殖策略是否可以通过特定的花的特征，如自花授粉的时间来可靠地识别？(4)特定交配系统的进化是否导致了花特征的可预测的变化？ 研究人员将专注于研究上述问题的理想系统--Collinsieae部落，这是一组多样化的本地一年生草本植物，它们显示出自交和远交策略之间重复进化转变的证据。 这项研究将包括野外和实验室研究，利用遗传、发育和生态学数据，精确地解决整个部落人口的交配系统，并重建群体中交配系统变化的动态历史。生物学家和遗传学家对自交的进化特别感兴趣，他们早就认识到它可以迅速导致遗传变异的丧失，有害性状的表达，以及进化潜力的丧失 不同的（相互矛盾的）假说提出来解释进化的自交策略没有得到充分的测试和自交系是否可以产生远系与长期的进化前景的基本问题仍然没有答案。 解决这些问题将极大地推进进化生物学，也是这项研究的主要目标。

This study addresses fundamental questions about the evolution of plant mating systems: (1) Why does self-pollination evolve? (2) Is selfing an evolutionary dead-end? (3) Can selfing vs. outbreeding strategies be reliably identified by particular floral features, such as timing of self-pollination? (4) Does evolution of particular mating systems lead to predictable changes in floral characteristics? The investigators will focus on an ideal system for investigating the above questions--the tribe Collinsieae, a diverse group of native, annual herbs that show evidence of repeated evolutionary shifts between selfing and outbreeding strategies. The research will involve field and laboratory studies to resolve precisely the mating systems of populations throughout the tribe, using genetic, developmental, and ecological data, and to reconstruct the dynamic history of mating-system change in the group.Evolution of selfing is of special interest to biologists and geneticists, who have long recognized that it can rapidly cause the loss of genetic variation, expression of deleterious traits, and loss of evolutionary potential. Different (conflicting) hypotheses proposed to explain evolution of selfing strategies have not been adequately tested and the basic question of whether selfing lineages can spawn outbreeding lines with long-term evolutionary prospects remains unanswered. Resolving these issues would greatly advance evolutionary biology and is a primary goal of this investigation.