PRF: Multiply-sired Fruits in Field Populations of Lesquerella fendler: Occurence and Mechanisms

虽然性选择作为一种重要的 植物进化中的一个重要因素现在已经被认识到， 令人惊讶的是，关于条件 其行动所需的。 一个迹象表明， 植物性选择的机会是发生 繁殖后代 这些水果是明确的证据， 来自一个以上配偶的花粉可用于使种子受精， 因此表明雌性选择雄性竞争 （性选择的形式）可能起作用。 然而，有详细的 只有一个关于多产水果的频率的知识 单一的引进物种 私家侦探将研究 和机制导致繁殖水果为本地人 西南沙漠的一种植物，Lesquerella fendleri。 到 确定频率，P.I.将确定种子的亲子关系 从植物在3个不同的群体在塞维利亚长期 生态研究基地。 初步研究表明， Lesquerella果实通常是多繁殖的。 确定 机制造成繁殖水果两种方法将是 满员你 一是亲子关系产生的单一性和多重性 自然界中的传粉者访问将被比较。 第二，观察 传粉者的访问率将被用来构建一个现实的 人工授粉的时间表，以调查 在更可控的条件下进行单次和多次访视。 了解负责机制不仅有助于 预测哪些物种可能产生多亲后代 水果，但可以帮助划定其可能的进化 后果

While the potential for sexual selection as an important factor in plant evolution is now becoming recognized, there is surprisingly little direct knowledge about how often conditions required for its actions occur. One indication of the opportunity for sexual selection in plants is the occurrence of multiply sired fruits. Such fruits are unambiguous evidence that pollen from more than one mate was available to fertilize seeds, and therefore indicate that female choice of male competition (forms of sexual selection) may act. However, there is detailed knowledge about the frequency of multiply sired fruits for only a single, introduced species. The P.I. will study the occurrence of and mechanisms causing multiply sired fruits for a native plant of South Western deserts, Lesquerella fendleri. To determine frequency, the P.I. will ascertain paternity for seeds from plants in 3 separate populations at the Sevilleta Long-Term Ecological Research Site. Preliminary studies indicate that Lesquerella fruits are commonly multiply sired. To determine the mechanisms causing multiply sired fruits two approaches will be taken. First, paternity resulting from single and multiple pollinator visits in nature will be compared. Second, observed pollinator visitation rates will be used to construct a realistic schedule of hand pollinations to investigate the effects of single and multiple visits under more controlled conditions. Knowledge of the responsible mechanisms will not only help to predict which species are likely to produce multiply sired fruits, but can help delimit their possible evolutionary consequences.