Fine mapping of qSdr9, a novel locus for seed dormancy (SD) in weedy rice, and development of NILs with a strong SD allele

• Published in: Molecular breeding Vol. 40; no. 8
• Main Authors: Nguyen, Thanhliem, Fu, Kai, Mou, Changling, Yu, Jiangfeng, Zhu, Xingjie, Huang, Yunshuai, Zhou, Chunlei, Hao, Qixian, Zhang, Fulin, Song, Weihan, Wang, Ping, Chen, Yaping, Ma, Tengfei, Tian, Yunlu, Liu, Shijia, Jiang, Ling, Wan, Jianmin
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2020; Springer Nature B.V
• Subjects: Alleles; Biomedical and Life Sciences; Biotechnology; Cereal crops; Chromosome 9; Chromosomes; Crop yield; Dormancy; Gene mapping; Genetics; Germination; Harvesting; Life Sciences; Mapping; Markers; Molecular biology; Phenotypic variations; Phenotyping; Plant biology; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Quantitative trait loci; Rice; Seeds; Weeds; QTL; Pre-harvest sprouting; Near-isogenic line
• ISSN: 1380-3743; 1572-9788
• DOI: 10.1007/s11032-020-01148-2

Lack of seed dormancy, a major cause of pre-harvest sprouting in rice and other cereal crops, causes significant reductions in grain yield and quality. Weedy rice is often strongly dormant; therefore, quantitative trait loci (QTLs) related to seed dormancy in weedy rice “Ludao” could be useful for improving pre-harvest sprouting resistance in the important japonica variety “Ninggeng 4.” To identify SD QTLs in variety Ludao, we constructed an advanced backcross population (BC 6 F 2 ) of Ninggeng 4 with Ludao as the donor parent by marker-assisted backcrossing followed by SD phenotyping. The consistently detected QTL qSdr9 on chromosome 9L explained 18.09% of the phenotypic variance, and the Ludao allele decreased germination percentage by 10.78%. qSdr9 was fine-mapped to a 586.60 kb region between markers QNU9–10 and RM5777. Based on the closest linked marker for locus qSdr9 , we developed near-isogenic lines with the qSdr9 allele from Ludao in Ninggeng 4 background. The qSdr9 near-isogenic lines with strong SD will be useful as parents in breeding for pre-harvest sprouting resistance.