Laboratório de Biologia Floral e Reprodutiva and Programa de Pós-Graduação em Biologia Vegetal, Departamento de Botânica, Universidade Federal de Pernambuco, Recife, 50670-901, Pernambuco, Brazil.
Kunming Institute of Botany, Chinese Academy of Sciences, 123, Lanhei Road, Panlong District, Kunming, 650201, China.
J Plant Res. 2024 Jan;137(1):65-77. doi: 10.1007/s10265-023-01508-x. Epub 2023 Nov 22.
Several barriers contribute to reproductive isolation between plant species, which can be classified as pre- or post-pollination. Understanding the strength of these barriers could clarify the factors that maintain reproductive isolation and thus species integrity. In this study, we quantified reproductive isolation between two bat-pollinated co-occurring Bauhinia species (B. acuruana and B. pentandra) with similar flower morphology. Over the course of 18 months, we assessed reproductive isolation between these two Bauhinia species by quantifying the individual strengths and absolute contributions of five pre- and post- pollination barriers. Our data showed that both species are completely isolated in their reproduction by a combination of several barriers. Although they co-occur in a few populations, we found a high degree of geographic isolation between them. And although their flowering periods overlap, there is a significant difference in flowering peaks. Both species have the same pollinating bats, but the interspecific transfer of pollen between the plant species may be reduced due to the different length of the flower stamens, resulting in different pollen deposition on the bats' bodies. We have documented complete incompatibility between taxa and conclude that pre- and post-pollination barriers are important factors in preventing gene flow, even in contact zones between these two species of Bauhinia. We highlight that our work is the first study to use methods to estimate the strength of reproductive isolation barriers between bat-pollinated species.
几种障碍导致植物物种之间的生殖隔离，可以分为授粉前或授粉后障碍。了解这些障碍的强度可以阐明维持生殖隔离和物种完整性的因素。在这项研究中，我们量化了两种蝙蝠授粉的共现紫荆属物种（Bauhinia acuruana 和 B. pentandra）之间的生殖隔离，它们具有相似的花形态。在 18 个月的时间里，我们通过量化五个授粉前和授粉后障碍的个体强度和绝对贡献来评估这两个 Bauhinia 物种之间的生殖隔离。我们的数据表明，这两个物种通过多种障碍的组合完全隔离了它们的繁殖。尽管它们在少数几个种群中共存，但我们发现它们之间存在高度的地理隔离。尽管它们的花期重叠，但开花高峰期有很大的差异。这两个物种都有相同的蝙蝠授粉者，但由于花的雄蕊长度不同，种间花粉转移可能会减少，导致蝙蝠身上的花粉沉积不同。我们已经记录了分类群之间的完全不兼容性，并得出结论，授粉前和授粉后障碍是防止基因流动的重要因素，即使在这两个 Bauhinia 物种的接触区也是如此。我们强调，我们的工作是首次使用方法来估计蝙蝠授粉物种之间生殖隔离障碍的强度。
