Allopolyploids possess complete sets of genomes derived from different parental species and exhibit a range of variation in various traits. Reproductive traits may play a key role in the reproductive isolation between allopolyploids and their parental species, thus affecting the thriving of allopolyploids. However, empirical data, especially in natural habitats, comparing reproductive trait variation between allopolyploids and their parental species remain rare. Here, we documented the flowering phenology and floral morphology of the allopolyploid wild plant Cardamine flexuosa and its diploid parents C. amara and C. hirsuta in their native range in Switzerland. The flowering of C. flexuosa started at an intermediate time compared with those of the parents and the flowering period of C. flexuosa overlapped with those of the parents. Cardamine flexuosa resembled C. hirsuta in the size of flowers and petals and the length/width ratio of petals, while it resembled C. amara in the length/width ratio of flowers. These results provide empirical evidence of the trait-dependent variation of allopolyploid phenotypes in natural habitats at the local scale. They also suggest that the variation in some reproductive traits in C. flexuosa is associated with self-fertilization. Therefore, it is helpful to consider the mating system in furthering the understanding of the processes that may have shaped trait variation in polyploids in nature.

中文翻译：

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异源多倍体弯碎米荠的开花物候和花形态与自然生境中亲本二倍体的性状相似性。


异源多倍体拥有源自不同亲本物种的完整基因组，并在各种性状上表现出一系列变异。生殖性状可能在异源多倍体与其亲本物种之间的生殖隔离中发挥关键作用，从而影响异源多倍体的繁荣。然而，比较异源多倍体与其亲本物种之间生殖性状变异的经验数据，特别是在自然栖息地中，仍然很少。在这里，我们记录了异源多倍体野生植物弯碎米荠及其二倍体亲本 C. amara 和 C. hirsuta 在瑞士原生地的开花物候和花卉形态。与亲本相比，屈曲花开始开花的时间较晚，花期与亲本有重叠。碎米花的花、花瓣大小和花瓣长宽比与毛碎米荠相似，花长宽比与阿马拉碎米荠相似。这些结果提供了局部尺度自然栖息地中异源多倍体表型的性状依赖性变异的经验证据。他们还表明，C. flexuosa 某些生殖性状的变异与自体受精有关。因此，考虑交配系统有助于进一步理解自然界中多倍体性状变异的过程。