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

PRF：香茅田间繁殖果实：发生和机制

• 批准号: 9203203
• 负责人: Randall Mitchell
• 金额: $ 6.96万
• 依托单位: Individual Award
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-01 至 1994-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9203203&HistoricalAwards=false
• 关键词: PRF; Multiply; sired; Fruits; Field

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.

尽管性选择作为植物进化的重要因素的潜力现在已经被认可，但令人惊讶的是，直接了解其行动所需的频率发生。 在植物中进行性选择机会的一种迹象是出现多重艾sired果实。 这样的果实是明确的证据表明，来自多个伴侣的花粉可用于施肥种子，因此表明女性对男性竞争的选择（性选择形式）可能会起作用。 但是，只有一个介绍的物种，就乘以乘水果的频率有详细的知识。 P.I.将研究为西南沙漠的本地植物Lesquerella Fendleri造成多种饲养水果的发生和机制的发生。 为了确定频率，P.I.将确定Sevilleta长期生态研究地点的3个单独人群中植物的种子的亲子关系。 初步研究表明，lesquerella水果通常是繁殖的。 为了确定导致乘积果实的机制，将采用两种方法。 首先，将比较自然界中单次传粉媒介访问引起的亲子关系。 其次，观察到的授粉探视率将用于构建实际的手授粉时间表，以研究在更受控条件下单次和多次访问的影响。 对负责任机制的了解不仅将有助于预测哪些物种可能会产生多重的饲养水果，而且可以帮助界定其可能的进化后果。