Key Roles of De-Domestication and Novel Mutation in Origin and Diversification of Global Weedy Rice

• Main Authors: Yong-Qing Zhu, Jia Fang, Ying Wang, Li-Hao Pang, Bao-Rong Lu
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Biology
• Subjects: differentiation; feral origin; genetic structure; introgression; networking analysis; seed shattering
• Online Access: https://www.mdpi.com/2079-7737/10/9/828

Agricultural weeds pose great challenges to sustainable crop production, owing to their complex origins and abundant genetic diversity. Weedy rice (WD) infests rice fields worldwide causing tremendous losses of rice yield/quality. To explore WD origins and evolution, we analyzed DNA sequence polymorphisms of the seed shattering genes (<i>sh4</i> and <i>qsh1</i>) in weedy, wild, and cultivated rice from a worldwide distribution. We also used microsatellite and insertion/deletion molecular fingerprinting to determine their genetic relationship and structure. Results indicate multiple origins of WD with most samples having evolved from their cultivated progenitors and a few samples from wild rice. WD that evolved from de-domestication showed distinct genetic structures associated with <i>indica</i> and <i>japonica</i> rice differentiation. In addition, the weed-unique haplotypes that were only identified in the WD samples suggest their novel mutations. Findings in this study demonstrate the key role of de-domestication in WD origins, in which <i>indica</i> and <i>japonica</i> cultivars stimulated further evolution and divergence of WD in various agroecosystems. Furthermore, novel mutations promote continued evolution and genetic diversity of WD adapting to different environments. Knowledge generated from this study provides deep insights into the origin and evolution of conspecific weeds, in addition to the design of effective measures to control these weeds.