Goodwillie Carol
Department of Biology, East Carolina University, Howell Science Complex, Greenville, North Carolina 27858, USA.
Evolution. 2008 Aug;62(8):2105-11. doi: 10.1111/j.1558-5646.2008.00429.x. Epub 2008 May 27.
A stochastic computer simulation model was created to compare the combined effects of selection and genetic drift on the dynamics of S-alleles under full sporophytic self-incompatibility (SI) versus transient SI, a form of partial SI in which flowers become self-compatible as they age. S-alleles were lost more rapidly with transient than with full SI, as is expected with weakened frequency-dependent selection. Based on these results, equilibrium S-allele diversity is expected to be lower with partial SI for populations of comparable size and migration rates. Consistent with model results, a comparison of the proportion of incompatible crosses in full diallel experiments for a fully SI and a transiently SI species in the annual genus Leptosiphon suggests that S-allele diversity is lower in the partially SI species. Results of the simulation model indicate that the transmission advantage of self-fertilization can have complex effects on S-allele dynamics in partial SI systems.
创建了一个随机计算机模拟模型，以比较在完全孢子体自交不亲和（SI）与瞬时SI（部分SI的一种形式，其中花朵随着年龄增长而变得自交亲和）情况下，选择和遗传漂变对S等位基因动态的综合影响。如预期的那样，随着频率依赖选择的减弱，S等位基因在瞬时SI下比在完全SI下更快丢失。基于这些结果，对于具有可比大小和迁移率的种群，部分SI下的平衡S等位基因多样性预计会更低。与模型结果一致，对一年生薄柱草属中一个完全SI物种和一个瞬时SI物种的完全双列杂交实验中不亲和杂交比例的比较表明，部分SI物种的S等位基因多样性较低。模拟模型的结果表明，自花受精的传递优势可能对部分SI系统中的S等位基因动态产生复杂影响。
