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适应能力，以减少近亲繁殖。仅在开花植物中，就有数量惊人的适应来阻止近亲繁殖，但这些系统经常崩溃。导致自花授粉的突变应该享有两个主要的选择优势。导致自花授粉的突变将在自然界传播，要么是因为它们享有基因水平的传递优势，要么是因为它们在授粉不确定的情况下提高了种子产量。还没有研究同时测试这些机制并评估它们的相互作用，因此还不能很好地理解为什么异花授粉机制反复崩溃。在这个项目中，导致自花授粉的突变将被杂交到一个典型的异花授粉的基因组中，重复的田间实验将检查这种突变是否由于遗传或生态原因而传播。该项目将确定导致进化转变为近亲繁殖的机制，这将危及植物生物多样性。该项目将培训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雪松林地研究中心(CCGs)协调的公共推广活动中展示他们的成果。学生参与直接外展的过程将向公众传播进化和保护生物学的原理。该小组亦会与各小组的科学教育工作者合作，发展一项针对K-12学生的授粉生态实地练习，以收录在小组出版的《雪松林地活动指南》内，供多名本地科学教师使用。

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.