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

不同花色的植物物种是理解维持变异的进化过程的极好模型。然而，被花吸引并随后授粉的昆虫在紫外线光谱中感知颜色，许多植物都有紫外线花的图案（即紫外线反射程度的变化），这是人类肉眼看不到的。UV花颜色进化的主要假设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施加自然选择。这两种假设都没有得到充分的检验，因此我们对影响昆虫花型的进化过程的综合看法还远远不够。本项目将利用Potentilla来解决这一问题，Potentilla是一种对花的紫外线模式高度可变的植物属，一些物种有图案的花，而另一些物种则吸收或反射紫外线。本研究将研究属内的进化关系，并描述所有物种的花性状和栖息地，以揭示紫外线模式下的进化转变。此外，基于现场的实验将测试紫外线模式多样化的假定生物和非生物驱动因素。了解花色多样性的演变对保护生物多样性具有重要意义。此外，了解植物传粉媒介的相互作用对农业具有重要的实际意义。这些植物的遗传数据将通过公共数据库提供。该项目包括指导几名本科生进行科学过程以及研究生培训。该项目还将包括通过匹兹堡大学中学外展计划进行外展，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.