DISSERTATION RESEARCH: Phylogeny, reticulate evolution, and historical biogeography in the Hawaiian lobeliad genera Cyanea and Clermontia

论文研究：夏威夷半叶莲属 Cyanea 和 Clermontia 的系统发育、网状进化和历史生物地理学

• 批准号: 1702007
• 负责人: Thomas Givnish
• 金额: $ 1.99万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1702007&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Phylogeny; reticulate; evolution

Adaptive radiations, where a group of organisms has radiated to perform a number of ecological roles, offer an opportunity to investigate the mechanisms that allow species to diversify rapidly within a limited geographical area. Members of the lobelia plant family (Lobeliaceae) restricted to the Hawaiian Islands have undergone a remarkable divergence in habitat, growth form, leaf size and shape, floral morphology, and mechanism of seed dispersal, and are considered one of the best examples of an adaptive radiation in plants. Previous studies have shown that this group of 140 species was derived from a single colonization 13 million years ago, long before many of the Hawaiian islands of today had emerged from the Pacific. Hawaiian lobeliads now represent 12% of the native Hawaiian flora and are the most species-rich plant lineage found on any single group of oceanic islands on Earth. The two largest genera, Cyanea and Clermontia, comprising approximately 100 species form the largest sublineage within the group. Previous phylogenetic analyses of Cyanea-Clermontia were inconclusive due to a combination of limited sampling within the group and insufficient DNA sequence variation to reconstruct a well-supported estimate of relationships. Cyanea-Clermontia, by its very size, ecological and morphological diversity, and high proportion of species restricted to single islands (each of known age), offers unique opportunities for studying adaptive radiation, speciation, and historical biogeography. Understanding relationships within this lineage could provide new insights into the rise of plant and animal diversity on Hawaii, and identify traits associated with a tendency to become rare or extinct. This project will (1) broadly train a graduate student in plant systematics and historical biogeography analyses; (2) develop molecular phylogenetic analysis pipelines to aid in the study of other recent radiations; (3) produce a well-documented collection of DNA samples to permit future studies of this important group; and (4) create a website on the diversification of native Hawaiian lobeliads, to disseminate findings to a broad range of amateur botanists and lobeliad enthusiasts.Next-generation DNA sequencing data will be used to infer phylogenies of Cyanea-Clermontia from whole-chloroplast genomes and 400 nuclear genes for all living species sampled across their range. Analyses of these data will permit derivation of species trees and networks, analysis of hybridization, introgression, and other forms of reticulate evolution (important in Clermontia), reconstruct its geographic spread through time, and infer the pattern and tempo of evolution of key morphological and ecological character-states using a variety of tree- and network-based approaches.

一组生物体辐射以执行多种生态作用的自适应辐射提供了一个机会，可以调查使物种在有限的地理区域内迅速多样化的机制。仅限于夏威夷群岛的Lobelia Plant家族（Lobeliaceae）的成员在栖息地，生长形式，叶片大小和形状，花卉分散的机制中存在显着差异，被认为是植物中适应性辐射的最佳实例之一。先前的研究表明，这一组140种是从1300万年前的一个殖民化中得出的，早在今天的许多夏威夷群岛就从太平洋出现了。现在，夏威夷小叶占夏威夷本地植物群的12％，是地球上任何一组海洋岛上发现的最丰富物种的植物谱系。两个最大的属Cyanea和Clermontia属，约100种构成了该组中最大的sublineage。由于该组中有限的采样和DNA序列变化不足以重建良好支持的关系估计值，因此蓝甲植物的先前系统发育分析尚无定论。 Cyanea-Clermontia的规模，生态和形态学多样性以及仅限于单个岛屿（已知年龄）的物种比例很高，为研究适应性辐射，形成性和历史生物地理学提供了独特的机会。了解这种血统中的关系可以为夏威夷动植物多样性的兴起提供新的见解，并确定与稀有或灭绝的趋势相关的特征。该项目将（1）广泛培训植物系统学和历史生物地理分析的研究生； （2）开发分子系统发育分析管道，以帮助研究其他近期辐射； （3）生产有据可查的DNA样品集合，以允许对这一重要组的未来研究； （4）创建一个有关夏威夷原住民叶lipelia的多元化的网站，以将发现的发现传播到各种各样的业余植物学家和Lobeliad的爱好者中。Next-Generation-Generation-Generation DNA测序数据将用于推断从整个氯氯植物基因组中的Cyanea-Clermontia的系统发育。这些数据的分析将允许衍生物种树木和网络，杂交分析，渗入和其他形式的网状演化（在克莱蒙蒂亚（Clermontia）中很重要），在时间上重建其地理位置，并推断出使用各种树和网络方法的关键形态和生态特征态的进化模式和速度。