Phylogenetic investigation of Asparagus L. trait evolution, phylogeography and diversification

花园芦笋是芦笋属植物中的200多个品种之一。野生芦笋种类从南非南端、整个欧洲到亚洲东部，在生长形式和繁殖方式上表现出显著的差异。尽管花园芦笋是一种非木本植物，具有肉质的根，但许多其他物种生产木质茎作为灌木丛或宿存藤本植物，还有其他物种生产土豆一样的块茎。人们熟悉的菜园芦笋有单独的产生花粉的雄株和结实的雌株，而它的大多数近亲是两性的-这意味着这种花有雄花和雌花的结合。先前的假设表明，这种高水平的多样性是由于环境条件的变化而适应地理传播的结果。这项研究的目的是确定芦笋在什么时候、哪里和在什么环境条件下出现这种多样化的生长和繁殖策略。研究人员将使用基因组方法来解决所有已描述的芦笋物种之间的系统发育关系，然后确定生长形式和繁殖模式的变化如何与环境变化和生物地理传播相关。这些发现将允许对未来植物如何适应不断变化的环境进行建模。这将对国内芦笋的栽培和生产具有重要意义。例如，这些结果将为芦笋育种者提供信息，以帮助开发能够在南加州日益干旱或美国中西部和东北部潮湿环境中的真菌病原体面前茁壮成长的新品种。最先进的基因组、表型和建模方法将被用于开发芦笋属强大的、全面的系统发育，并阐明其动态生物地理历史和对不同环境条件的适应。田园芦笋已经成为雌雄异株进化的典范。这个项目将扩大我们对芦笋性状多样性进化的理解，包括贮藏根形、地上部结构和落叶、光合作用茎代替叶片的发育，以及叶片转化为具有不同形式和功能的退化的、非光合作用的鳞片和刺。结合物种水平的系统基因组学、环境数据和表现学，我们将测试遗传、生态和进化过程之间的相互作用，这些过程在过去500-1000万年来一直推动芦笋的多样化。已经为种内高通量表型分析开发的新的图像分析方法将被扩展到对地上部和根构型的宏观进化变化进行建模。这些发展将推动物种内和物种间生物多样性研究的新方向。这一奖项反映了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。

Garden asparagus is one of more than two hundred species within the plant genus Asparagus. Wild Asparagus species range from the southern tip of South Africa, throughout Europe to the eastern reaches of Asia, and exhibit remarkable variation in growth forms and modes of reproduction. Whereas garden asparagus is a non-woody species with fleshy roots, many other species produce woody stems as bushes or persistent vines, and still other species produce potato-like tuberous root. The familiar garden asparagus has separate pollen-producing male and fruit-bearing female plants, whereas most of its relatives are hermaphroditic - meaning the flower has both male and female parts combined. Previous hypotheses suggest that this high level of diversity is the result of adaptation to geographic spread due to changing environmental conditions. The objective of this research is to determine when, where and under what environmental conditions this diversity of growth and reproduction strategies arose within Asparagus. The researchers will use genomic methods to resolve the phylogenetic relationships among all described Asparagus species and then determine how changes in growth form and mode of reproduction correlate with environmental changes and biogeographic spread. The findings will allow generalizations for modeling how plants may adapt to changing environments in the future. This, in turn, will be significant to cultivation and production of domestic Asparagus. For example, the results will provide asparagus breeders information to help develop new varieties that can thrive in the face of increasing droughts in Southern California or fungal pathogens in the moist environments of the Midwest and Northeastern U.S.State-of-the-art genomic, phenotyping and modeling approaches will be utilized to develop a robust, comprehensive phylogeny for the genus Asparagus, and to elucidate its dynamic biogeographic history and adaptations to varied environmental conditions. Garden asparagus (A. officinalis) is already a model for the evolution of dioecy. This project will expand our understanding of the evolution of trait diversity in Asparagus to include storage root form, shoot architecture and deciduousness, the development of photosynthetic stems in place of leaves, and the transformation of leaves into reduced, non-photosynthetic scales and thorns with diverse forms and functions. Integrating species-level phylogenomics, environmental data, and phenomics, we will test for interactions among the genetic, ecological and evolutionary processes that have been driving diversification within Asparagus over the last 5-10 million years. Novel methods of image analysis that have been developed for intraspecific high-throughput phenotyping will be expanded to model macroevolutionary changes in shoot and root architecture. These developments will propel new lines of research on both within species and interspecific biodiversity.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.