Trapnell Dorset W, Hamrick J L
Department of Plant Biology, University of Georgia, Athens, Georgia 30602 USA;
Am J Bot. 2006 Jul;93(7):1010-8. doi: 10.3732/ajb.93.7.1010.
Pollinator behavior plays a central role in determining patterns of pollen-mediated gene movement in zoophilous angiosperms. A species' floral display can strongly influence the behavior of its pollinators and thereby affect its evolutionary pathway. We used paternity analysis to directly measure and describe mating patterns within 15 populations of the epiphytic orchid, Laelia rubescens, in Costa Rican dry forest. Strict correlated mating by orchids allows inference of the precise multilocus diploid genotype of the pollen parents. Our data show that mean effective population sizes were small (11.2 in 1999 and 11.8 in 2000) relative to the number of flowering genets (63 and 56, respectively). Fewer genets were reproductively successful as females than males. The relationship between reproductive success (RS) and floral display within three cluster size classes was consistent between years, with large (>30 inflorescences) and small (≤10 inflorescences) clusters often having significantly lower RS than expected, while the RS of medium-sized clusters (11-30 inflorescences) often significantly exceeded expectations. Paternity analysis allowed us to take advantage of the pollination biology of L. rubescens to provide unusually detailed insights into mating patterns, pollen-mediated gene movement and RS for populations of this epiphytic orchid, an herbaceous perennial, distributed in three-dimensional space.
传粉者行为在决定虫媒被子植物中花粉介导的基因流动模式方面起着核心作用。一个物种的花展示能强烈影响其传粉者的行为，从而影响其进化途径。我们利用父系分析直接测量和描述了哥斯达黎加干燥森林中15个附生兰花种群——鲁氏蕾丽兰（Laelia rubescens）内的交配模式。兰花严格的相关交配使得能够推断花粉亲本精确的多位点二倍体基因型。我们的数据表明，相对于开花基株的数量（1999年为63株，2000年为56株），平均有效种群规模较小（1999年为11.2，2000年为11.8）。作为母本繁殖成功的基株比作为父本的少。在三个聚类大小类别中，繁殖成功率（RS）与花展示之间的关系在不同年份是一致的，大的（>30个花序）和小的（≤10个花序）聚类的繁殖成功率往往显著低于预期，而中等大小聚类（11 - 30个花序）的繁殖成功率往往显著超过预期。父系分析使我们能够利用鲁氏蕾丽兰的传粉生物学，对这种附生兰花种群（一种多年生草本植物，分布于三维空间）的交配模式、花粉介导的基因流动和繁殖成功率提供异常详细的见解。
