Department of Genetics, Kazimierz Wielki University, Bydgoszcz, Poland.
Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland.
Mol Ecol Resour. 2021 Apr;21(3):781-800. doi: 10.1111/1755-0998.13307. Epub 2020 Dec 28.
Individual differences in male reproductive success drive genetic drift and natural selection, altering genetic variation and phenotypic trait distributions in future generations. Therefore, identifying the determinants of reproductive success is important for understanding the ecology and evolution of plants. Here, based on the spatially explicit mating model (the neighborhood model), we develop a hierarchical probability model that links co-dominant genotypes of offspring and candidate parents with phenotypic determinants of male reproductive success. The model accounts for pollen dispersal, genotyping errors as well as individual variation in selfing, pollen immigration, and differentiation of immigrant pollen pools. Unlike the classic neighborhood model approach, our approach is specially designed to account for excessive variation (overdispersion) in male fecundity. We implemented a Bayesian estimation method (the Windows computer program available at: https://www.ukw.edu.pl/pracownicy/plik/igor_chybicki/1806/) that, among others, allows for selecting phenotypic variables important for male fecundity and assessing the fraction of variance in fecundity (R ) explained by selected variables. Simulations showed that our method outperforms both the classic neighborhood model and the two-step approach, where fecundities and the effects of phenotypic variables are estimated separately. The analysis of two data examples showed that in wind-pollinated trees, male fecundity depends on both the amount of produced pollen and the ability to pollen spread. However, despite that the tree size was positively correlated with male fecundity, it explained only a fraction of the total variance in fecundity, indicating the presence of additional factors. Finally, case studies highlighted the importance of accounting for pollen dispersal in the estimation of fecundity determinants.
个体间雄性生殖成功的差异会驱动遗传漂变和自然选择，从而改变未来世代的遗传变异和表型特征分布。因此，确定生殖成功的决定因素对于理解植物的生态和进化至关重要。在这里，我们基于空间明确的交配模型（邻域模型），开发了一个层次概率模型，将后代和候选亲本的共显性基因型与雄性生殖成功的表型决定因素联系起来。该模型考虑了花粉扩散、基因型错误以及自交、花粉传入和传入花粉库分化的个体变异。与经典的邻域模型方法不同，我们的方法专门用于解释雄性繁殖力的过度变异（过离散）。我们实施了一种贝叶斯估计方法（可在 https://www.ukw.edu.pl/pracownicy/plik/igor_chybicki/1806/ 上找到的 Windows 计算机程序），该方法除其他外，允许选择对雄性繁殖力重要的表型变量，并评估选定变量解释繁殖力变异的分数（R）。模拟结果表明，我们的方法优于经典邻域模型和两步法，后两种方法分别估计繁殖力和表型变量的效应。对两个数据实例的分析表明，在风媒传粉的树木中，雄性繁殖力取决于产生的花粉量和花粉传播的能力。然而，尽管树木大小与雄性繁殖力呈正相关，但它仅解释了繁殖力总变异的一部分，表明存在其他因素。最后，案例研究强调了在估计繁殖力决定因素时考虑花粉扩散的重要性。
