The role of hybridization and polyploidy in plant evolution

杂交和多倍体在植物进化中的作用

• 批准号: 8087-2007
• 负责人: Allen, Geraldine
• 金额: $ 1.05万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=474325
• 关键词: role; hybridization; polyploidy; plant; evolution

Hybridization (interbreeding of species) and polyploidy (chromosome doubling) are widespread phenomena in the flowering plants. Together they lead to new combinations of traits that can become stabilized as new allopolyploid species, with fundamental consequences for plant evolution. This is often of practical importance, for example when assessing the taxonomic status of rare species or the consequences of interbreeding between crop plants and related weeds. It is therefore important to understand how polyploid hybrids arise and evolve. This work focuses on the importance of hybridization in two distinct plant groups, fawn-lilies (Erythronium) and North American asters (Symphyotrichum). Evolutionary relationships are well understood in these groups, allowing hybrids to be readily detected using molecular tools. This project makes use of DNA sequence data from specific chloroplast and nuclear gene regions that give fine-scale resolution of relationships. It has several components: (1) phylogenetic analyses and detection of hybridization (especially leading to polyploid hybrids) in these groups; (2) determination of hybrid frequency and parentage; and (3) investigation of the genetic characteristics of allopolyploids, including changes in duplicated genes, by comparison of natural allopolyploid species with their parent species and by synthesis of artificial hybrids from the same parents. This work will enhance understanding of the ways in which new genetic forms are created and maintained in plants.

杂交（物种杂交）和多倍体（染色体加倍）是开花植物中普遍存在的现象。它们共同产生新的性状组合，这些性状组合可以稳定为新的异源多倍体物种，对植物进化产生根本性影响。这通常具有实际重要性，例如在评估稀有物种的分类地位或农作物与相关杂草之间杂交的后果时。因此，了解多倍体杂种如何产生和进化非常重要。这项工作的重点是杂交在两个不同植物群中的重要性，即小鹿百合（Erythrium）和北美紫苑（Symphyotrichum）。这些群体中的进化关系已被充分理解，因此可以使用分子工具轻松检测到杂交种。该项目利用来自特定叶绿体和核基因区域的 DNA 序列数据，提供精细的关系解析。它有几个组成部分：（1）系统发育分析和这些群体中杂交（特别是导致多倍体杂种）的检测； (2) 杂交频率和亲本的确定； (3) 通过天然异源多倍体物种与其亲本物种的比较以及通过从相同亲本合成人工杂交种来研究异源多倍体的遗传特征，包括重复基因的变化。这项工作将增进对植物中新遗传形式的产生和维持方式的理解。