DISSERTATION RESEARCH: Testing long-standing adaptive hypotheses for floral traits in the UV spectrum using comparative methods

花色不同的植物物种是理解维持变异的进化过程的极好模型。然而，被花吸引并随后为其授粉的昆虫在紫外线(UV)光谱中感知颜色，许多植物具有肉眼看不到的UV花朵图案(即UV反射程度的变化)。紫外花颜色进化的主要假说是传粉者的吸引力和效率。然而，像非生物压力这样的因素也可能迫使自然选择。这两个假说都没有得到充分的检验，因此，我们远不能像昆虫所看到的那样，对影响花卉模式的进化过程提出综合的看法。这个项目将使用委陵菜来解决这一差距，委陵菜是一种高度可变的植物属，它具有花朵的紫外线模式，一些物种具有花纹，而另一些物种则具有紫外线吸收或反射。这项研究将研究该属内的进化关系，并表征所有物种的花卉特征和栖息地，以揭示紫外线模式的进化转变。此外，实地实验将测试紫外线模式多样化的可能生物和非生物驱动因素。了解花卉颜色多样性的演变对于保护生物多样性具有重要意义。此外，了解植物传粉者之间的相互作用对农业具有重要的实际意义。有关这些植物的基因数据将通过公共数据库提供。该项目包括在科学过程中指导几名本科生以及研究生培训。该项目还将包括通过匹兹堡大学中学外联方案进行外联，包括教师培训和课堂参与。

Plant species that vary in flower color are excellent models for understanding the evolutionary processes that maintain variation. However, the insects that are attracted to the flowers and subsequently pollinate them perceive color in the ultraviolet (UV) spectrum, and many plants have UV floral patterns (i.e., variation in the degree of UV reflectance) that go unseen by the naked human eye. The main hypothesis for the evolution of UV flower color is pollinator attraction and efficiency. However, factors like abiotic stress may also impose natural selection. Neither of these hypotheses has been adequately tested, thus we are far from a synthetic view of the evolutionary processes influencing floral patterns as they appear to insects. This project will address this gap using Potentilla, a plant genus highly variable for floral UV pattern, some species have patterned flowers while others are UV-absorptive or reflective. The research will examine the evolutionary relationships within the genus and characterize floral traits and habitat for all species to reveal evolutionary transitions in UV pattern. Further, field-based experiments will test putative biotic and abiotic drivers of UV pattern diversification. Understanding the evolution of diversity of flower color is important to conservation of biodiversity. In addition, understanding plant pollinator interactions has important practical implications for agriculture. Genetic data on the plants will be made available through public databases. The project includes mentoring several undergraduates in the scientific process as well as graduate student training. The project will also include outreach through the University of Pittsburgh Middle School Outreach Program, including teacher training and classroom participation.