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

本研究解决了植物交配系统进化的基本问题：(1)自花授粉为何进化？(2)自恋是进化的死胡同吗？(3)自交和远交策略是否可以通过特定的花特征（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会导致花的特征发生可预测的变化？研究人员将把重点放在一个理想的系统上，以调查上述问题——collinsiae部落，一个多样化的本地一年生草本植物群体，显示出在自交和近亲繁殖策略之间反复进化的证据。这项研究将包括实地和实验室研究，利用遗传、发育和生态数据，精确地解决整个部落人口的交配系统，并重建该群体交配系统变化的动态历史。生物学家和遗传学家对自恋的进化特别感兴趣，他们早就认识到自恋会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。为解释自交策略的进化而提出的不同（相互矛盾的）假设尚未得到充分的检验，自交谱系能否产生具有长期进化前景的远交系这一基本问题仍未得到解答。解决这些问题将极大地推进进化生物学，也是本研究的主要目标。

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.