Systematics and evolution of parasitic plants

寄生植物的系统学和进化

• 批准号: RGPIN-2017-05304
• 负责人: Costea, Mihai
• 金额: $ 2.04万
• 依托单位: Wilfrid Laurier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682839
• 关键词: Systematics; evolution; parasitic; plants

Parasitic plants take water and nutrients from other plants called hosts. Some parasitic plants, referred to as “obligate”, depend entirely on their hosts for survival and negatively affect their growth and development. The proposed research program focuses on the species diversity and evolution of Cuscuta (dodder), a taxonomically challenging group of obligate parasitic plants comprising ~ 200 species distributed worldwide. The taxonomical difficulties of Cuscuta arise in part because the morphological variation among species is minimal and hidden inside the small flowers (~ 3 mm long). In addition, the recently documented hybrid formation of species (reticulate evolution) complicates the reconstruction of evolutionary histories. This parasitic group is particularly important because native dodders are keystone species in their ecosystems. However, Cuscuta is also economically important because some of its species are agricultural and horticultural pests that cause major yield losses in numerous crops. *** The first short-term objective of the proposed research is to unravel species-level evolutionary histories within four unstudied groups of Cuscuta, and to uncover the depth and extent of reticulate evolution in two other groups in which we have previously shown that hybrid speciation occurs. We will use molecular and morphological data to understand how species have evolved, based on which we will also revise their taxonomy. New species are likely to be discovered as a part of this research. *** Cuscuta has a pronounced variation of the chromosome number (polyploidy) and the second short-term aim of this research is to elucidate how the extra sets of chromosomes have been acquired and to identify the role that these changes had in the evolution of dodders. Since reticulate evolution and polyploidy often work in tandem, the chromosome data will provide a more thorough understanding of how hybrid species originated.*** The host range is an essential attribute of any parasitic organism and represents the totality of hosts that the parasite can attack. The third short-term objective of this research program aims to characterize for the first time the host range and its evolution in Cuscuta. The study of the host range has been hindered in Cuscuta because most dodders infest many hosts from numerous botanical families. To solve this problem, we will obtain host data from tens of thousands of herbarium specimens, and use novel analytical approaches employed in animal parasites. *** Overall, this research program is part of the ongoing global efforts to catalog life on Earth and understand its natural history and evolution. From a practical point of view, the results will facilitate a better identification and management of both native and pest Cuscuta species from Canada and the rest of the world. Host range results can be used to model and predict the potential expansion of pest dodders.

寄生植物从称为寄主的其他植物中获取水分和养分，一些寄生植物完全依赖寄主生存，并对寄主的生长和发育产生负面影响。菟丝子（菟丝子）是一类在分类学上具有挑战性的专性寄生植物，分布于世界各地，约有 200 种。菟丝子的分类困难部分是因为物种之间的形态变异很小且隐藏。此外，最近记录的物种杂交形成（网状进化）使进化历史的重建变得复杂，因为本地菟丝子是其生态系统中的关键物种。菟丝子在经济上也很重要，因为它的一些物种是农业和园艺害虫，会导致许多作物严重减产。 *** 该研究的第一个短期目标是揭示四种物种水平的进化历史。我们将利用分子和形态学数据来了解物种是如何进化的，并在此基础上揭示未经研究的菟丝子类群的网状进化的深度和程度。作为这项研究的一部分，可能会发现新的物种。 *** 菟丝子的染色体数量有明显的变异（多倍体），这项研究的第二个短期目标是。阐明额外的染色体组是如何获得的，并确定这些变化在菟丝子进化中的作用，由于网状进化和多倍体通常协同作用，染色体数据将提供对杂交物种如何起源的更全面的了解。 *** 宿主范围是任何寄生生物的基本属性，代表了寄生虫可以攻击的宿主的总体。该研究计划的第三个短期目标旨在首次描述宿主范围及其进化。菟丝子。对菟丝子寄主范围的研究受到了阻碍，因为大多数菟丝子感染了许多植物科的许多寄主。为了解决这个问题，我们将从数以万计的植物标本中获取寄主数据，并使用动物寄生虫中采用的新颖分析方法。 *** 总的来说，该研究项目是全球持续努力的一部分，旨在对地球上的生命进行编目并了解其自然历史和进化，从实践的角度来看，其结果将有助于更好地识别和管理本地菟丝子和害虫菟丝子。来自加拿大的物种以及世界其他地区的宿主范围结果可用于模拟和预测害虫菟丝子的潜在扩张。