title: Frequent introgressions from diploid species contribute to the adaptation of the tetraploid Shepherd's purse (Capsella bursa-pastoris).
abstract: Adaptation 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 tetraploid 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 polyploids. 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 polyploids as well. We conclude that frequent introgressions from congeneric diploids contributed to the acquisition of adequate genetic variations, thereby allowing C. bursa-pastoris to adapt to various habitats across the world. Our results highlight how a polyploid could have successfully established after it originated.
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Ting-Shen
authors: TS
authors: Han
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Qiong
authors: Q
authors: Wu
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Xing-Hui
authors: XH
authors: Hou
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Zi-Wen
authors: ZW
authors: Li
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Yu-Pan
authors: YP
authors: Zou
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors: Song
authors: S
authors: Ge
authors: State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China. Electronic address: yalong.guo@ibcas.ac.cn.
authors: Ya-Long
authors: YL
authors: Guo
mesh_terms: D000222:Adaptation, Physiological; D005075:Biological Evolution; D029687:Capsella / Q000235:genetics* / Q000502:physiology; D004171:Diploidy; D014644:Genetic Variation; D057891:Tetraploidy
keywords: Capsella bursa-pastoris; adaptation; introgression; polyploid