Assortative mating is a deviation from random mating based on phenotypic similarity. As it is much better studied in animals than in plants, we investigate for trees whether kinship of realized mating pairs deviates from what is expected from the set of potential mates and use this information to infer mating biases that may result from kin recognition and/or assortative mating. Our analysis covers 20 species of trees for which microsatellite data is available for adult populations (potential mates) as well as seed arrays. We test whether mean relatedness of observed mating pairs deviates from null expectations that only take pollen dispersal distances into account (estimated from the same data set). This allows the identification of elevated as well as reduced kinship among realized mating pairs, indicative of positive and negative assortative mating, respectively. The test is also able to distinguish elevated biparental inbreeding that occurs solely as a result of related pairs growing closer to each other from further assortativeness. Assortative mating in trees appears potentially common but not ubiquitous: nine data sets show mating bias with elevated inbreeding, nine do not deviate significantly from the null expectation, and two show mating bias with reduced inbreeding. While our data sets lack direct information on phenology, our investigation of the phenological literature for each species identifies flowering phenology as a potential driver of positive assortative mating (leading to elevated inbreeding) in trees. Since active kin recognition provides an alternative hypothesis for these patterns, we encourage further investigations on the processes and traits that influence mating patterns in trees.

中文翻译：

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对树木中交配偏差的分析。

分类交配是基于表型相似性的随机交配的偏离。由于在动物方面比在植物方面进行的研究要好得多，因此我们针对树木调查了已实现的配对对的亲缘关系是否偏离潜在配偶对的亲缘关系，并使用此信息来推断可能由亲属识别和/或导致的配偶偏见。分类交配。我们的分析涵盖了20种树木，这些树木的微卫星数据可用于成年种群（潜在配偶）以及种子阵列。我们测试观察到的交配对的平均相关性是否偏离仅考虑花粉分散距离的空预期（根据同一数据集估算）。这样可以在已实现的配对中识别亲缘关系高低的亲属，分别指示正向和负向交配。该测试还能够区分仅由于相关对彼此之间越来越近而导致的双亲近亲繁殖的进一步发展。树木中的交配似乎很普遍，但并不普遍：九个数据集显示近交增加时的交配偏差，九个数据集与零期望值没有显着偏离，两个数据集显示近交减少了的交配偏差。虽然我们的数据集缺乏有关物候的直接信息，但是我们对每种物种的物候文献的研究都将开花物候视为树中正向交配交配（导致近交繁殖增加）的潜在驱动力。由于主动的亲属识别为这些模式提供了另一种假设，