Dissertation Research: Phylogenetic analysis of the Neotropical plant genus Clusia (Clusiaceae)

山竹是山竹科灌木和乔木的一个热带类群，约有300种。Clusia植物有许多显著的特征，使它们对研究很重要。除了是少数几种可以在其他植物（附生植物）上生长的树木和灌木之一，Clusia是唯一已知的具有天冬酸代谢（CAM）光合作用的树木群，在夜间，温度较低，水分损失减少，吸收碳（CO2）。它也是仅有的两种开花植物之一，其中一些物种的花产生花树脂而不是花蜜作为对传粉者的奖励。该项目旨在利用全基因组DNA序列数据来了解Clusia物种之间的关系，并估计该组CAM光合作用和花树脂的进化史。研究结果将使研究人员能够理解植物对水分胁迫的适应模式，并为授粉奖励系统的进化提供新的见解。综上所述，这些结果将有助于我们更好地理解植物是如何进化的，以及它们是如何适应不同环境的。一名研究生和一名本科生将接受分子系统和解剖方法的培训。该项目的数据还将用于加强Rancho Santa Ana植物园的夏季研究项目，该项目为来自美国主要本科院校的学生提供研究经验和培训。该研究的结果也将在大众科学杂志上广泛传播。这项工作的重点是重建系统发育关系的新热带植物属clusiia （Clusiaceae）使用系统发育数据。所得到的系统发育将用于：1)测试目前已识别的部分的单系性并修订属的分类；2)研究CAM光合作用在类群内的分布并重建其进化模式；3)重建属内产树脂花的进化。由此产生的分析将为植物生理学和植物与传粉者的相互作用提供更好的一般理解。

Clusia is a tropical group of about 300 species of shrubs and trees in the mangosteen family (Clusiaceae). Clusia plants have a number of notable characteristics that make them important for study. In addition to being one of the few trees and shrubs to grow on other plants (epiphytes), Clusia is the only known tree group to have Crassulacean Acid Metabolism (CAM) photosynthesis in which carbon (CO2) is absorbed during the night, when temperatures are lower and water loss is reduced. It is also one of only two groups of flowering plants in which flowers of some species produce floral resins instead of nectar as reward for pollinators. This project seeks to use genome-wide DNA sequence data to understand how species of Clusia are related to each other, and to estimate the evolutionary history of CAM photosynthesis and floral resins in the group. Results will enable the researchers to understand patterns of plant adaptation to water stress, and provide new insights into the evolution of pollination reward systems. Taken together, these results will permit a better understanding of how plants have evolved and how they have adapted to different environments. One graduate student and an undergraduate will be trained in molecular systematic and anatomical methods. Data from the project will also be used to enhance a summer research program at Rancho Santa Ana Botanical Garden that provides research experiences and training for students from Principally Undergraduate Institutions across the U.S. Results from the study will also be broadly disseminated in popular science magazines. This work focuses on reconstructing phylogenetic relationships in the Neotropical plant genus Clusia (Clusiaceae) using phylogenomic data. The resulting phylogeny will be used to: 1) test the monophyly of currently recognized sections and revise the classification for the genus, 2) investigate the distribution of CAM photosynthesis within the group and reconstruct the pattern of its evolution, and 3) reconstruct the evolution of resin-producing flowers within the genus. The resulting analyses will provide a better general understanding of plant physiology and plant-pollinator interactions.