DISSERTATION RESEARCH: Evolutionary Genetics of Asexual Reproduction in a Wild Plant Species

论文研究：野生植物无性繁殖的进化遗传学

• 批准号: 1311269
• 负责人: Thomas Mitchell-Olds
• 金额: $ 2.04万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-15 至 2016-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1311269&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Evolutionary; Genetics; Asexual

Despite the prevalence of sexual reproduction in nature, asexual reproduction is also found in many diverse organisms. Apomixis (asexual reproduction via clonal seed) occurs in approximately 400 genera across 40 different plant families, and is always associated with polyploidy (whole genome duplication) and hybridization. To date, these confounding factors have prevented investigation of the evolutionary and ecological processes maintaining apomixis in plant populations. The genus Boechera, a self-fertilizing wild relative of Arabidopsis thaliana, contains diploid apomicts. This offers a unique opportunity to disentangle the factors underlying apomixis and polyploidy. The proposed research examines the processes underlying a sexual/apomictic breeding system polymorphism in wild populations of Boechera, using population genetic models that historically are designed for diploid organisms. Understanding the link between apomixis and hybridization still remains problematic. Any putative fitness effects of apomixis may be due to hybridization, which introduces genetic variation to inbred Boechera. Through a combination of crossing experiments, field research, and genomic sequencing techniques, the PIs will investigate the fitness effects of hybridization and increased genetic diversity in Boechera. This research permits complete separation of these two confounding factors from the study of apomixis for the first time. Most crops are of hybrid origin, and the introduction of apomixis promises fixation of advantageous lineages through their clonal offspring; therefore, apomixis is of great agricultural interest. A developed understanding of the evolutionary maintenance of this breeding system in nature is critical to current and future efforts to battle hunger across the world. Training of students will occur.

尽管自然界中有性繁殖的流行率，但在许多不同的生物体中也发现了无性繁殖。 apomixis（通过克隆种子的无性繁殖）在40个不同植物家族的大约400属中发生，并且始终与多倍体（整个基因组重复）和杂交有关。迄今为止，这些混杂因素阻止了对植物种群中维持Apomixis的进化和生态过程的研究。 Boechera属是拟南芥的野生亲戚，其中包含二倍体的apomicts。这提供了一个独特的机会，可以消除apomixis和多倍体的基本因素。拟议的研究研究了Boechera野生种群中性/副育种系统多态性的过程，使用历史上是为二倍体生物设计的种群遗传模型。了解Apomixis与杂交之间的联系仍然有问题。 Apomixis的任何推定适应性效应都可能是由于杂交引起的，这将遗传变异引入了近交易所。通过交叉实验，现场研究和基因组测序技术的结合，PI将研究杂交的适应性和Boechera遗传多样性的增加。这项研究允许首次将这两个混杂因素与Apomixis的研究完全分开。大多数农作物都是混合起源，引入Apomixis有望通过其克隆后代固定有利的谱系。因此，Apomixis具有极大的农业利益。对本质上这种育种系统的进化维护的已发达理解对于当前和未来的努力与全世界的饥饿作斗争至关重要。将对学生进行培训。