ABR: Natural Selection in Radish Raphanus spp.

人们认为，花的大小、颜色和形态的惊人多样性是为了更好地吸引传粉者和提高传粉效率而进行的自然选择。然而，直到最近，传粉成功与否的估计仅仅基于一朵花繁殖成功的一个组成部分，即产生的种子。在一个物种中，花的颜色或形式比其他变体产生更多的种子，被认为具有整体的进化优势。然而，大多数花通过种子（雌性功能）和花粉（雄性功能）繁殖。遗传给后代的基因有一半是由花粉贡献的，但我们几乎不知道花的特征对花粉的影响，但我们几乎不知道花的特征对花粉供体（雄性）功能的影响。由于我们知识上的这一差距，我们对花的理解以及塑造它们的进化力量需要重新审视。这项研究项目的资助期限为一年，旨在了解开花植物的花卉特征如何影响雄性和雌性的繁殖。首席研究员已经证明，对于两种野生萝卜（北美两岸农业土地上大量的杂草），花瓣颜色、花瓣大小和花粉产量的变化会影响繁殖。最重要的是，雄性生殖似乎更强烈地受到花变异的影响，而不是种子生产。为了了解这些杂草物种如何增殖和进化，必须了解影响雄性提供花粉功能的因素。在更新期间，首席研究员将研究花粉粒数和大小对进化适合度的影响。研究结果对杂草控制和作物育种具有启示意义。

The striking diversity of size, color, and form seen in flowers is thought to have arisen by natural selection for greater pollinator attractiveness as well as enhanced pollination efficiency. Until quite recently, however, estimates of pollination success were based solely upon one component of a flower's reproductive success, i.e. the seeds produced. Flower colors or forms that set more seeds than other variants seen within a species have been presumed to enjoy an overall evolutionary advantage. Most flowers, however, reproduce through both seeds (female function) and pollen (male function). One- half of the genes transmitted to future generations are contributed by pollen, but we know almost nothing about the impact of flower features on pollen, but we know almost nothing about the impact of flower features on pollen donating (male) function. Because of this gap in our knowledge, our understanding of flowers and the evolutionary forces that have shaped them is in need of major re-examination. The research program for which this grant is a one-year renewal is designed to understand how floral features influence both male and female reproduction by flowering plants. The principal investigator has shown, for two species of wild radish (abundant weeds of agricultural land on both coasts of North America), that variation for petal color, petal size, and pollen production can influence reproduction. Most importantly, male reproduction seems to be more strongly influenced by floral variation than seed production. To understand how these weedy species proliferate and evolve, the factors influencing male, pollen-donating function must be understood. During the renewal period, the principal investigator will study the effects of pollen grain number and size upon evolutionary fitness. The results have implications for weed control, as well as for crop breeding.