The eu-bromelioid clade provides a classic example of an exceptionally rapid radiation, in which many closely related species are found in sympatry. In this respect, species cohesion may be due to the rapid evolution of strong reproductive barriers, although interspecific and intergeneric hybridization is observed in the family. The objective of this study was to characterize the breeding systems and post-pollination reproductive barriers in Wittmackia patentissima and Hohenbergia ridleyi. Previously included in Aechmea, they show an almost complete absence of pre-pollination barriers, although their recent divergence may not have allowed time for complete ecological/reproductive isolation to have evolved. In manual pollinations, both species had > 40% fruit set in self and outcross treatments, but seed set from manual self-pollinations was < 50% that of outcrosses, and spontaneous self-pollination produced fewer than three seeds per fruit. Self-pollen and pollen tubes showed no evidence of self-incompatibility, but heterospecific pollen tubes were arrested in the lower part of the style and heterospecific seed set was zero in both species. The combination of self-compatibility and strong post-pollination, pre-fertilization reproductive barriers is consistent with the involvement of breeding system reproductive barriers in allowing closely related bromeliad species to occur in sympatry.

中文翻译：

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巴西大西洋森林中两个紧密相关的类溴目拟南芥（凤梨科）之间的生殖系统和授粉后障碍

eu-类胸腺类进化枝提供了异常快速的辐射的经典例子，在辐射中发现了许多密切相关的物种。在这方面，物种凝聚力可能是由于强大的生殖屏障的快速进化所致，尽管在该家族中观察到种间和属间杂交。这项研究的目的是表征Wittmackia patentissima和Hohenbergia ridleyi的繁殖系统和授粉后的繁殖障碍。以前包含在Aechmea中，尽管它们最近的分歧可能没有为完全的生态/生殖隔离发展提供时间，但它们显示出几乎完全没有传粉前的障碍。在人工授粉中，两个物种在自交和异源处理中结实率均> 40％，但是来自人工自花授粉的结实率<异源结实率的50％，并且自发自花授粉每个水果产生的种子少于三颗。自花粉和花粉管没有自我不相容的迹象，但异种花粉管在花柱下部被捕，这两个物种的异种种子集为零。自相容性与强后花授粉相结合，