Evolution and ecology of plant sexual systems

植物性系统的进化与生态学

• 批准号: 355954-2008
• 负责人: Dorken, Marcel
• 金额: $ 1.82万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=497585
• 关键词: Evolution; ecology; plant; sexual; systems

Evolutionary transitions that occur repeatedly over the course of history are of inherent interest to biologists. One such transition involves a fundamental change in the way organisms reproduce and has occurred at least 100 times in the flowering plants alone: the evolution of separate sexes from hermaphroditism. During this transition, individuals cease being able to reproduce as both female and male parents (i.e., hermaphrodites) and instead act solely as mothers or fathers to their offspring (i.e., dioecy). Why should individuals give up one of their sex roles to become specialist females or males? Biologists going back to Darwin have thought about this question, but two key issues remain unclear - issues that can begin to be resolved using the combination of modern molecular genetics and experimental manipulations that characterizes the research proposed here. First, the importance of ecological conditions in evolutionary transitions to dioecy is widely recognized but poorly understood. I will provide the first empirical investigation of the effects of environmental conditions on a key step in the evolution of dioecy - the evolution of males - using experiments and genetic analysis of the native plant Sagittaria latifolia. This species is unusual in having both dioecious and hermaphroditic populations, making it an ideal experimental system. Second, there is evidence that dioecious lineages contain fewer species than hermaphrodite lineages, but the processes responsible are largely unknown. Much can be learned about the effect of combined vs. separate sexes on patterns of diversity using lineages that have undergone rapid diversification in their sexual systems. The Canary Islands radiation of Echium appears to be such a lineage, with one quarter of species having dimorphic breeding systems. Using genetic and field studies of Echium, I will investigate the historical and contemporary processes that shape the evolution of combined vs. separate sexes. The combination of approaches proposed here will provide (a) novel insights into the evolution of dioecy, and (b) training for students in high-throughput molecular genetics, and advanced experimental design and statistics - highly sought skills across a range of biological careers.

在历史过程中反复发生的进化转变是生物学家固有的兴趣。其中一个转变涉及生物体繁殖方式的根本变化，仅在开花植物中就发生了至少100次：从雌雄同体进化为单独的性别。在这个过渡期间，个体不再能够作为雌性和雄性父母繁殖（即，雌雄同体）而代之以仅作为其后代的母亲或父亲（即，diocyanine）。为什么个人要放弃他们的性别角色之一，成为专业女性或男性？早在达尔文时代，生物学家就已经思考过这个问题，但有两个关键问题仍然不清楚--这些问题可以开始通过结合现代分子遗传学和实验操作来解决，而实验操作正是本文所提出的研究的特征。首先，生态条件的重要性，在进化过渡到diophthalmic被广泛承认，但了解甚少。我将提供第一个实证调查的环境条件的影响的关键步骤，在进化的dioclonal-进化的男性-使用实验和遗传分析的本地植物慈姑。本种在雌雄异株和雌雄同体的种群中是不寻常的，使其成为理想的实验系统。第二，有证据表明雌雄异株谱系比雌雄同体谱系包含更少的物种，但负责的过程在很大程度上是未知的。利用在其性系统中经历了快速多样化的谱系，可以了解到很多关于结合与分离的性别对多样性模式的影响。加那利群岛的Echium辐射似乎是这样的血统，四分之一的物种具有二型繁殖系统。使用Echium的遗传和实地研究，我将调查历史和当代的过程，塑造了组合与单独的性别的演变。本文提出的方法组合将提供（a）对雌雄异株进化的新见解，以及（B）为学生提供高通量分子遗传学以及先进实验设计和统计学方面的培训--这些是一系列生物学领域中备受追捧的技能。职业。