Fenster Charles B
Department of Biology, Barnes Laboratory, The University of Chicago, 5630 S. Ingleside Avenue, Chicago, IL, 60637, USA.
Evolution. 1991 Mar;45(2):398-409. doi: 10.1111/j.1558-5646.1991.tb04413.x.
Both pollen and seed dispersal components of gene flow were examined in the annual plant Chamaecrista fasciculata (Leguminosae) and quantified in terms of Wright's neighborhood area. Pollen dispersal was estimated by measuring pollinator flight movement throughout the flowering season and the contribution of pollen carryover to pollen dispersal was determined by comparing pollinator flight movement with dispersal of electrophoretic markers in an experimental transect. Phenological effects on the probability of fruit set were measured to determine whether pollinations should be weighted differentially across the flowering season. The outcrossing rate, a major determinant of the role of pollen dispersal in gene flow, was estimated from electrophoretic analysis of progeny arrays and by measuring the proportion of nongeitonogamous pollinator flight movements. Seed dispersal was measured in a prairie habitat and in experimental plots without surrounding vegetation. Seed dispersal was small in comparison to pollen dispersal in both environments. Fruit set was low at the beginning and end of the flowering season, periods when flower density is low and pollinator flight distances are large. Although the outcrossing rate was high (t = 80%) and pollen carryover substantial, pollen dispersal was limited. Averaged over 4 years, neighborhood area, based on both seed and pollen dispersal, was 17.6 m , and corresponds to a circle of radius 2.4 m. The observed limited gene dispersal suggests the population of C. fasciculata is genetically subdivided into small breeding units of related individuals.
在一年生植物束花豆（豆科）中，研究了基因流的花粉和种子传播成分，并根据赖特邻域面积进行了量化。通过测量整个开花季节传粉者的飞行移动来估计花粉传播，并通过在实验样带中将传粉者的飞行移动与电泳标记的传播进行比较，确定花粉残留对花粉传播的贡献。测量了物候对坐果概率的影响，以确定在整个开花季节授粉是否应进行不同加权。异交率是花粉传播在基因流中作用的一个主要决定因素，通过对后代阵列的电泳分析以及测量非同株异花传粉者飞行移动的比例来估计。在草原栖息地和没有周围植被的实验地块中测量了种子传播。在这两种环境中，种子传播与花粉传播相比都较小。在开花季节开始和结束时坐果率较低，此时花密度低且传粉者飞行距离大。尽管异交率很高（t = 80%）且花粉残留量大，但花粉传播是有限的。基于种子和花粉传播，4年的平均邻域面积为17.6平方米，相当于半径为2.4米的圆。观察到的有限基因扩散表明，束花豆种群在遗传上被细分为相关个体的小繁殖单位。
