Genetic basis of the early heading of high-latitude weedy rice

• Published in: Frontiers in plant science Vol. 13; p. 1059197
• Main Authors: Li, Zhuan, Gui, Rui, Yu, Xiaoyu, Liang, Chengwei, Cui, Juan, Zhao, Xue, Zhang, Xuemin, Yu, Pengcheng, Chen, Wenfu, Sun, Jian
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 05.12.2022
• Subjects: genetic resources; GWAS; heading date; Plant Science; QTL mapping; weedy rice; genetic resources; GWAS; weedy rice; heading date; QTL mapping
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2022.1059197

rice ( L.) is an important staple food in high-latitude regions and is widely distributed in northern China, Japan, Korea, and Europe. However, the genetic diversity of rice is relatively narrow and poorly adapted. Weedy rice ( ) is a semi-domesticated rice. Its headings are earlier than the accompanied rice, making it a potential new genetic resource, which can make up for the defects of wild rice that are difficult to be directly applied to rice improvement caused by reproductive isolation. In this study, we applied a natural population consisting of weedy rice, landrace, and cultivar to conduct a genome-wide association study (GWAS) of the heading date and found four loci that could explain the natural variation of the heading date in this population. At the same time, we developed recombinant inbred lines (RILs) crossed by the early-heading weedy rice WR04-6 and its accompanied cultivar ShenNong 265 (SN265) to carry out a QTL mapping analysis of the heading date and mapped four quantitative trait locus (QTLs) and three epistatic effect gene pairs. The major locus on chromosome 6 overlapped with the GWAS result. Further analysis found that two genes, and , on chromosome 6 (Locus 2 and Locus 3) may be the key points of the early-heading character of weedy rice. As minor effect genes, and also have genetic contributions to the early heading of weedy rice. In the process of developing the RIL population, we introduced fragments of Locus 2 and Locus 3 from the weedy rice into super-high-yielding rice, which successfully promoted its heading date by at least 10 days and expanded the rice suitable cultivation area northward by about 400 km. This study successfully revealed the genetic basis of the early heading of weedy rice and provided a new idea for the genetic improvement of cultivated rice by weedy rice.