Schoen Daniel J, Brown Anthony H D
Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, PQ, H3A 1B1, CANADA.
CSIRO Division of Plant Industry, G.P.O. Box 1600, Canberra, 2601, AUSTRALIA.
Evolution. 1991 Nov;45(7):1651-1664. doi: 10.1111/j.1558-5646.1991.tb02670.x.
The overall rate of self-fertilization can be viewed as the sum of two distinct processes: 1) self-pollination of all ovules in a flower (whole-flower self-pollination); and 2) self-pollination of some of the ovules in a flower, occurring together with outcrossing of the remaining ovules (part-flower self-pollination). In some situations these processes may be equated with different modes of self-pollination. A model of the mating system in which the progeny of separate fruits serve as the unit of observation is presented. The model partitions the overall rate of self-pollination into components attributable to whole- and part-flower selfing. When the mating system is estimated using information on marker genotypes from chasmogamous fruits in two species of Glycine together with the whole- and part-flower selfing model, the results indicate that the chasmogamous flowers in a subalpine population of G. clandestina underwent a significant level of whole-flower selfing, whereas in another, lower elevation population of G. clandestina and in a subtropical population of G. argyrea, they did not. This difference is thought to be related to the contrast in the variability of environmental conditions for insect-mediated pollination between the habitats sampled. In particular, the large component of whole-flower selfing observed in the subalpine population of G. clandestina may be due to self-pollination that is induced during periods unfavorable to insect-mediated pollination. It can be demonstrated that such induced selfing will be selected whenever environmental conditions are such that pollinator activity limits seed set, and moreover that induced selfing can result in the selection of overall levels of self-pollination that are intermediate between 0 and 1. Monte Carlo simulation is employed to show that ignoring the correlation of self-fertilization events that result from whole- and part-flower selfing may lead to biased estimates of mating system parameters.
1）一朵花中所有胚珠的自花授粉（整花自花授粉）；2）一朵花中部分胚珠的自花授粉，与其余胚珠的异花授粉同时发生（部分花自花授粉）。在某些情况下，这些过程可能等同于不同的自花授粉模式。本文提出了一个交配系统模型，其中以单个果实的后代作为观察单位。该模型将自花授粉的总体速率划分为可归因于整花和部分花自交的成分。当利用来自两种大豆的开花受精果实的标记基因型信息以及整花和部分花自交模型来估计交配系统时，结果表明，在地下大豆的一个亚高山种群中，开花受精的花朵经历了显著水平的整花自交，而在另一个海拔较低的地下大豆种群以及银叶大豆的一个亚热带种群中，情况并非如此。这种差异被认为与所采样栖息地中昆虫介导授粉的环境条件变异性的差异有关。特别是，在地下大豆的亚高山种群中观察到的整花自交的很大一部分可能是由于在不利于昆虫介导授粉的时期诱导的自花授粉。可以证明，只要环境条件使得传粉者活动限制了种子结实，这种诱导自交就会被选择，而且诱导自交可能导致选择介于0和1之间的自花授粉总体水平。采用蒙特卡罗模拟表明，忽略整花和部分花自交所导致的自花受精事件的相关性可能会导致交配系统参数的估计出现偏差。
