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.

尽管自然界中有性生殖普遍存在，但无性生殖也存在于许多不同的生物中。无融合生殖（通过克隆种子进行无性繁殖）发生在40个不同植物科的大约400个属中，并且总是与多倍体（全基因组复制）和杂交有关。迄今为止，这些混杂因素阻碍了植物种群中维持无融合生殖的进化和生态过程的研究。Boechera属是拟南芥（Arabidopsis thaliana）的自交野生近缘种，含有二倍体无融合生殖体。这提供了一个独特的机会，解开无融合生殖和多倍体的潜在因素。拟议的研究探讨的过程中的性/无融合生殖系统多态性野生种群的Boechera，使用人口遗传模型，历史上是为二倍体生物。理解无融合生殖和杂交之间的联系仍然是个问题。无融合生殖的任何推定的健身效果可能是由于杂交，引入遗传变异的近交Boechera。通过杂交实验，实地研究和基因组测序技术相结合，PI将调查杂交和增加Boechera遗传多样性的健身效果。本研究首次将这两个混杂因素从无融合生殖研究中完全分离出来。大多数作物都是杂交起源，无融合生殖的引入保证了优势谱系通过其克隆后代的固定;因此，无融合生殖在农业上具有很大的意义。对自然界中这种繁殖系统的进化维持的深入了解，对于当前和未来在世界范围内与饥饿作斗争的努力至关重要。学生的培训将会发生。