Devlin B, Ellstrand N C
Department of Botany and Plant Sciences and Program in Plant Genetics, University of California, Riverside, CA, 92521.
Evolution. 1990 Mar;44(2):248-259. doi: 10.1111/j.1558-5646.1990.tb05195.x.
While gene flow is an important factor determining the genetic structure of populations, there are few studies that quantify it empirically. Paternity-exclusion analysis has recently been employed to assess the number of seeds fathered by individuals from outside of a study population (gene flow by pollen), but appropriate estimation procedures have been limited to special cases. In this report, we illustrate a general Monte Carlo method that provides an approximate maximum-likelihood estimate of gene flow by pollen from paternity-exclusion analysis. We also show that the method can be used to estimate the number of foreign gametes received by individuals in the study population. Using these methods, we estimated that 7% and 6.3% of the seeds assayed from two wild radish populations were fathered by foreign pollen (95% confidence intervals = 5.0-9.0% and 5.4-7.2%, respectively). Each population was isolated from other radish populations by at least 150 m. Estimates of the number of foreign gametes received by individuals in a population were not correlated with selected reproductive or genetic characters, which included total flower production, total fruit production, seeds per fruit, flower color, floral phenology, and number of heterozygous marker loci.
虽然基因流是决定种群遗传结构的一个重要因素，但很少有研究对其进行实证量化。亲子排除分析最近已被用于评估来自研究种群外部的个体所产生的种子数量（花粉介导的基因流），但合适的估计程序仅限于特殊情况。在本报告中，我们阐述了一种通用的蒙特卡罗方法，该方法通过亲子排除分析提供花粉介导的基因流的近似最大似然估计。我们还表明，该方法可用于估计研究种群中个体所接收的外来配子数量。使用这些方法，我们估计，从两个野生萝卜种群检测的种子中，分别有7%和6.3%是由外来花粉受精产生的（95%置信区间分别为5.0 - 9.0%和5.4 - 7.2%）。每个种群与其他萝卜种群至少相隔150米。种群中个体所接收的外来配子数量估计值与选定的生殖或遗传特征无关，这些特征包括总花量、总果量、每果种子数、花色、花期物候以及杂合标记位点数量。
