DISSERTATION RESEARCH: How is the Selfing Syndrome Assembled? A Common Garden Fitness Study of its Component Parts

论文研究：自交综合症是如何形成的？

• 批准号: 1501954
• 负责人: Mark Rausher
• 金额: $ 2.06万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1501954&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; How; Selfing; Syndrome

This project will test five evolutionary explanations for why plants self-pollinate, which will deepen our understanding of an important characteristic of plant evolution and will improve our breeding of self-pollinating crops such as tomatoes, corn and soybeans. Plants reproduce in a variety of ways, and 10-15% of plant species are primarily self-pollinating. The evolutionary transition from outcrossing to selfing is often accompanied by reductions in many floral traits. The researchers will determine the genetic bases for these changes in the morning glory. The study species are closely related to the sweet potato, a key global food resource that has proven challenging for modern selective breeding. Genetic resources developed in this study may help in the creation of more vigorous and disease-resistant sweet potatoes.The transition to selfing is often accompanied by reductions in flower size, nectar production, pollen-ovule ratio, pigmentation, and the distance between the anther and stigma, collectively called the selfing syndrome. Five models of selfing syndrome evolution (resource allocation, marginal environment and florivory, efficiency of autogamous selfing, and general size reduction in response to inbreeding depression) will be tested by a combination of field and greenhouse experiments. Researchers will develop hybrid backcrossed lines between the morning glory species Ipomoea lacunosa, a selfing species, and its sister species, I. cordatotriloba, which both outcrosses and self-pollinates. The project will determine (1) whether traits in I. lacunosa characteristic of the selfing syndrome evolved in response to direct selection or were correlated responses to selection on other traits and, (2) what selective pressures encourage the adoption of the selfing syndrome. The investigators will measure selection on three selfing syndrome traits (pollen number, nectar volume, and corolla size) in a field experiment comprising 2400 individuals from a set of nearly isogenic lines and wild-type controls. Fitness will be assessed through three proxy measures: survival after transplant, seed set, and outcross paternity.

该项目将测试植物自花授粉的五种进化解释，这将加深我们对植物进化的一个重要特征的理解，并将改善我们对番茄、玉米和大豆等自花授粉作物的育种。植物以多种方式繁殖，10-15%的植物物种主要是自花授粉。从异交到自交的进化过渡通常伴随着许多花的性状的减少。研究人员将确定牵牛花这些变化的遗传基础。研究物种与甘薯密切相关，甘薯是一种重要的全球食物资源，已被证明对现代选择性育种具有挑战性。本研究中开发的遗传资源可能有助于创造更有活力和抗病性的甘薯。向自交的过渡通常伴随着花朵大小、花蜜产量、花粉胚珠比、色素沉着以及花药和柱头之间的距离的减少，统称为自交综合征。五个模型的自交综合征的演变（资源分配，边缘环境和florivory，自花受精的效率，和一般的大小减少，以应对近交衰退）将测试相结合的领域和温室实验。研究人员将在牵牛花品种Ipomoea lacunosa（一种自交品种）和它的姐妹品种I。cordatotriloba，既异交又自花授粉。该项目将确定（1）是否性状在I。（2）选择压力促使自交综合征的产生。研究人员将测量三个自交综合征性状（花粉数，花蜜量和花冠大小）的田间实验，包括2400个人从一组近等基因系和野生型对照。健康将通过三个代理措施进行评估：移植后的生存，种子集，和异交父系。