DISSERTATION RESEARCH: Quantifying pollen limitation and reproductive assurance mechanisms in Gesnariae species with contrasting pollination systems

在许多开花植物中，动物授粉是结实所必需的。然而，花卉访客并不总是传递足够的花粉来使所有的种子受精。这种现象被称为花粉限制，为了避免这种现象，许多植物进化出了自主自花授粉的机制。这项研究将量化花粉限制和自主自交对具有不同授粉系统的苦瓜亚科物种种子集的贡献。Gesnerieae是一个在大安的列斯群岛多样化的植物群。一些物种完全由蜂鸟或蝙蝠授粉，而另一些物种则是多面手(例如蝙蝠、蜂鸟和昆虫)。专科花卉平均每天接待一次访问，而多面手花卉每天接待多次访问。以前的工作表明，蜂鸟授粉的花粉限制与自交机制的存在之间存在联系。该项目旨在使用来自多米尼加共和国和波多黎各的12种Gesnerieae物种来证实这一发现。这项研究将阐明我们对安的列斯群岛一个研究较少的植物群中授粉系统和自交机制进化的潜在过程的理解。自交的发展可能对保护稀有的苦瓜科物种至关重要，因为它允许植物在没有传粉者的情况下繁殖。如果没有自我繁殖的能力，如果传粉者数量下降，植物灭绝的风险可能会更大。因此，这项研究既与我们对植物区系进化的理解有关，也与保护加勒比群岛脆弱生态系统中稀有和狭小分布的植物有关。

Animal pollination is essential for seed set in many flowering plants. However, floral visitors do not always transfer enough pollen to fertilize all seeds. This phenomenon is known as pollen limitation and to avoid it, many plants have evolved mechanisms of autonomous self-pollination. This study will quantify pollen limitation and the contribution of autonomous selfing to the seed set of Gesnerieae species with contrasting pollination systems. The Gesnerieae is a plant group that diversified in the Greater Antilles. Some species are exclusively pollinated by hummingbirds or bats, while others are generalists (e.g. bats, hummingbirds and insects). Specialist flowers receive in average one visit per day, while generalist flowers receive many visits per day. Previous work suggests a relationship between pollen limitation and the presence of selfing mechanisms with hummingbird pollination. This project is designed to corroborate this finding using twelve Gesnerieae species from Dominican Republic and Puerto Rico. The research will illuminate our understanding of the processes underlying the evolution of pollination systems and selfing mechanisms in a poorly studied plant group from the Antillean islands. The development of selfing could be critical to the conservation of rare Gesnerieae species since it allows plants to reproduce in the absence of pollinators. Without the ability to self, plants could be a greater risk of extinction if pollinator populations decline. Thus, this study is of relevance to both our understanding of floral evolution and the conservation of rare and narrowly distributed plants in the fragile ecosystems of the Caribbean archipelago.