Frequent Introgressions from Diploid Species Contribute to the Adaptation of the Tetraploid Shepherd＇s Purse （Capsella bursa-pastoris）

• Published in: 分子植物：英文版 Vol. 8; no. 3; pp. 427 - 438
• Main Author: Ting-Shen Han Qiong Wu Xing-Hui Hou Zi-Wen Li Yu-Pan Zou Song Ge Ya-Long Guo
• Format: Journal Article
• Language: English
• Published: 2015
• Subjects: 二倍体; 四倍体; 基因渗入; 多倍体植物; 模型系统; 生态分化; 荠菜; 蕨类植物
• ISSN: 1674-2052

is the most important ability for organisms to survive in diverse habitats. Animals have the option to escape from stressful environments, but plants do not. In plants, polyploids consist of about 30%-70% angiosperms and 95% ferns, of which some are important crops such as cotton and wheat. How polyploid plants adapt to various habitats has been a fundamental question remained largely unanswered. The tetra- ploid Shepherd＇s purse （Capsella bursa-pastoris） is one of the most successful plants on earth and has been distributed across the world, thus being an ideal model system for studying the adaptation of poly- ploids. We found that there are frequent introgressions from congeneric diploids to Shepherd＇s purse. Ecological niche modeling suggests that ecological differentiation is evident between the introgressed and non-introgressed C. bursa-pastoris, and the introgressions are a source of adaptation. This result links an evolutionary process to the adaptation of polyploids, and sheds light on the breeding strategy of poly- ploids as well. We conclude that frequent introgressions from congeneric diploids contributed to the acqui- sition of adequate genetic variations, thereby allowing C. bursa-pastoris to adapt to various habitats across the world. Our results highlight how a polypioid could have successfully established after it originated.