Quantifying the roles of pollination and post-pollination barriers in flowering plant speciation: a case study of the diverse Neotropical genus Burmeistera (Campanulaceae)

这个项目将研究开花植物如何随着时间的推移在物种之间形成生殖边界。动物传粉者对大多数开花植物的繁殖和生存至关重要，包括我们的许多农作物。传统观点认为，动物传粉者也在推动这些物种的多样性方面发挥了主要作用。然而，这一想法很少得到详细和大规模的测试。研究人员将使用Burmeistera来验证这一假设，Burmeistera是一个开花植物属，其116个物种依靠吃蜜的蝙蝠授粉。Burmeistera物种将花粉放置在蝙蝠头部的不同部分，这可能会减少物种之间的花粉和基因交换。它们之间也有不同程度的基因不相容。这些遗传障碍可能会降低跨物种授粉的受精成功率或杂交后代的存活率。研究人员将评估这些生殖障碍中的哪一种对Burmeistera物种形成过程的每个阶段起作用。本科生和研究生，包括来自代表性不足群体的学生，将参与该项目的所有方面，并将接受实地和实验室技术培训。该项目还将支持博士后研究员的专业发展。研究人员将通过密苏里州植物园的教育展示和Burmeistera物种的双语野外指南向公众交流结果。该项目将使用综合实验和比较方法来探索被子植物物种形成过程中生殖障碍的演变。研究人员将使用来自整个质体和700多个核基因座的DNA序列数据，构建Burmeistera(风铃花科)的强大物种水平系统发育图。然后，他们将测量授粉前和授粉后的生殖障碍，这些物种对具有不同的系统发育距离。评估将包括圈养的喂蜜蝙蝠的异花授粉试验，以及栽培物种的手交试验。研究人员将在系统发育的背景下比较这些测量方法，以检验授粉后生殖障碍先于其他人进化的假设。他们还将确定Burmeistera花的花粉产生和接受器官长度的变化是否与物种形成事件相关，这将与传粉者驱动的物种形成假说一致。项目成果将包括对被子植物物种形成过程的异常详细的探索，改进研究较少的新热带开花植物组内的分类范围，以及创建新的遗传资源和植物标本库。该项目将加强美国、厄瓜多尔和哥伦比亚科学家之间的国际研究合作。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project will investigate how flowering plants develop reproductive boundaries among species over time. Animal pollinators are critical to the reproduction and survival of most flowering plants, including many of our agricultural crops. Conventional wisdom holds that animal pollinators also have a primary role in driving the diversification of these species. However, this idea has rarely been tested in detail and at scale. Researchers will test this hypothesis using Burmeistera, a flowering plant genus whose 116 species depend on nectar-feeding bats for pollination. Burmeistera species place their pollen on different parts of the bats' heads, which may reduce the exchange of pollen and genes between species. They also have different degrees of genetic incompatibility with each other. These genetic barriers may reduce the fertilization success of cross-species pollinations or the survival of hybrid offspring. Researchers will evaluate which of these reproductive barriers contributes to each stage of the speciation process in Burmeistera. Undergraduate and graduate students, including those from underrepresented groups, will be involved in all aspects of the project and will be trained in field and laboratory techniques. The project will also support the professional development of a post-doctoral researcher. Researchers will communicate results to the public via educational displays at the Missouri Botanical Garden and bilingual field guides for Burmeistera species.This project will discover how reproductive barriers evolve during angiosperm speciation using an integrated experimental and comparative approach. Researchers will construct a robust species-level phylogeny for Burmeistera (Campanulaceae, the bell-flower family) using DNA sequence data from whole plastomes and over 700 nuclear loci. They will then measure pre- and post-pollination reproductive barriers among pairs of species having different phylogenetic distances. Assessment will include cross-pollination trials by captive nectar-feeding bats as well as hand-crosses of species in cultivation. Researchers will compare these measures within the context of the phylogeny to test the hypothesis that post-pollination reproductive barriers evolve before others. They will also determine whether changes in the length of pollen-bearing and receiving organs of Burmeistera flowers are correlated with speciation events, which would be consistent with the hypothesis of pollinator-driven speciation. Project outcomes will include an exceptionally detailed exploration of angiosperm speciation processes, improved taxonomic circumscriptions within a poorly-studied Neotropical flowering plant group, and the creation of new genetic resources and herbarium collections. The project will strengthen international research collaborations among US, Ecuadorian and Colombian scientists.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.