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Dissertation Research: Self-incompatibility and Pollination in Two Species of Linanthus

论文研究：两种亚麻属植物的自交不亲和性和授粉

基本信息

批准号：
9411869
负责人：
Douglas Schemske
金额：
$ 0.64万
依托单位：
University of Washington
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1994
资助国家：
美国
起止时间：
1994-09-01 至 1997-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9411869&HistoricalAwards=false
关键词：
Dissertation Research Self incompatibility Pollination

项目摘要

9411869 Schemske The great diversity of reproductive systems is a distinctive feature of higher plants. Self-incompatibility, a genetic system that prevents fertilization by self-pollen in hermaphroditic plants, is one of a number of mechanisms that promote outcrossing in higher plants. It is estimated to be present in over half of all angiosperm species. This phenomenon has important implications for plant breeding, and as a result its physiological and molecular bases have been the focus of extensive research. Self- incompatibility also plays an important role in the evolution of higher plants. The loss of self-incompatibility and evolution of selfing is thought to be a common evolutionary pattern in a number of angiosperm families. Yet despite an extensive literature on the major ecological and genetic factors favoring self-vs. cross fertilization, little is know about the specific factors involved in the origin or loss of self-incompatibility. The co-occurrence of two closely related annuals in the genus Linanthus presents an opportunity to investigate the relationship between self-incompatibility and mating system evolution. The two species are ecologically and morphologically similar, yet they are distinguished by their breeding systems: Linanthus parviflorus is self-incompatible, while an undescribed sympatric species is self- fertilizing. In comparing a number of ecological and genetic aspects of the two species, the proposed research will address the functional significance of self-incompatibility, focussing on unique features of the phenomenon. For instance, while a number of mechanisms of higher plants prevents self-fertilization, self- incompatibility is unique in that it also may prevent mating between close relatives. The evolutionary significance of this will be investigated. Another focus of the research will be the relationship between self-incompatibility and morphological floral characters that influence the deposition of se lf-pollen on the stigma. Information gained from this study will contribute to our understanding of the factors that influence the loss of self- incompatibility, a critical turning point in the course of mating system evolution in higher plants.

小行星9411869 生殖系统的多样性是高等植物的显著特征。自交不亲和性是两性植物中阻止自花花粉受精的遗传系统，是促进高等植物异交的众多机制之一。据估计，它存在于所有被子植物物种的一半以上。这一现象对植物育种具有重要意义，因此其生理和分子基础一直是广泛研究的焦点。自交不亲和性在高等植物的进化过程中也起着重要的作用. 自交不亲和性的丧失和自交进化被认为是被子植物许多科的共同进化模式。然而，尽管大量的文献中的主要生态和遗传因素有利于自花受精与异花受精，很少有人知道的起源或自交不亲和性的损失所涉及的具体因素。亚麻属中两种近缘的一年生植物的同时出现为研究自交不亲和性与交配系统进化之间的关系提供了机会。这两个物种在生态和形态上相似，但它们的繁殖系统不同：Linanthus parviflorus是自交不亲和的，而一个未描述的同域种是自交不亲和的。在比较这两个物种的生态和遗传方面的一些问题时，拟议的研究将解决自交不亲和的功能意义，重点是这种现象的独特特征。例如，虽然高等植物的许多机制阻止了自花受精，但自交不亲和性是独特的，因为它也可能阻止近亲之间的交配。这一点的进化意义将被研究。研究的另一个重点是自交不亲和性与影响花粉在柱头上沉积的花部形态特征之间的关系。研究结果将有助于我们了解影响自交不亲和性丧失的因素，这是高等植物交配系统进化过程中的一个关键转折点。