Collaborative Research: Integrating gene and individual level selection to understand the evolution of self-fertilization in flowering plants

在整个生物圈中，大多数生物都表现出某种减少近亲繁殖的适应性。仅在开花植物中，就有数量惊人的适应性来防止近亲繁殖，然而这些系统经常崩溃。引起自花授粉的突变应该有两个主要的选择优势。引起自花授粉的突变将在自然界中传播，要么是因为它们具有基因水平的传播优势，要么是因为它们在授粉不确定的情况下提高了种子产量。没有一项研究同时测试了这些机制并评估了它们的相互作用，所以我们不太清楚为什么异花授粉机制一再失败。在这个项目中，一个引起自花授粉的突变将被杂交到一个典型的异花授粉基因组中，重复的野外实验将检查这种突变的传播是由于遗传还是生态原因。该项目将确定导致近亲繁殖的进化转变的机制，这将危及植物的生物多样性。该项目将训练本科生和研究生使用遗传标记来推断亲子关系和基因流动模式，这是应用农业环境中的关键工具。学生们将在田纳西州Cedar Glades研究中心（CCGS）协调的公共宣传活动上展示他们的研究成果。学生参与直接外展的过程，将向公众传达进化和保护生物学的原理。他们还将与中国科学院的科学教育工作者合作，为K-12学生开发一项授粉生态学野外练习，该练习将被纳入中国科学院出版的《雪松林地活动指南》，并被许多当地科学教师使用。

Throughout the biosphere, most organisms display some sort of adaptation to reduce inbreeding. In flowering plants alone, there are a staggering number of adaptations that prevent inbreeding, yet these systems break down frequently. Mutations causing self-pollination should enjoy two major selective advantages. Mutations causing self-pollination will spread in nature either because they enjoy a gene-level transmission advantage or because they boost seed production when pollination is uncertain. No study has simultaneously tested these mechanisms and evaluated their interaction, so it is not well understood why outcross-pollination mechanisms repeatedly break down. In this project, a mutation causing self-pollination will be crossed into a typically outcross-pollinated genome and replicated field experiments will examine whether this mutation spreads because of genetic or ecological reasons. This project will identify the mechanisms that cause evolutionary shifts to inbreeding, which imperil plant biodiversity. The project will train undergraduate and graduate students to use genetic markers to infer parentage and patterns of gene flow, which are critical tools in applied agricultural settings. Students will present their results at public outreach events coordinated by the Center for Cedar Glades Studies (CCGS) in Tennessee. The involvement of students in the process of direct outreach will communicate the principles of evolution and conservation biology to the public. The PIs will also work with science educators at the CCGS to develop a pollination ecology field exercise aimed at K-12 students to be included in the "Cedar Glades Activity Guide" published by the CCGS and used by many local science teachers.