Characterization of a naturally occurring early-flowering rice mutant resulting from a novel variation in the Ghd7 locus

Abstract

Rice is one of the main staple food crops and is consumed by more than half of the global population. Optimizing the flowering time may help to maximize grain production. In this study, we characterized a rice mutant, Zixiangnuo early-flowering mutant (ZXN-E). Compared with the wild-type variety, Zixiangnuo (ZXN), the mutant plants flowered earlier, were shorter and produced smaller panicles. Bulked segregant analysis revealed a 7-bp deletion in the first exon of the Grain number, plant height, and heading date 7 (Ghd7) locus. The allele with the 7-bp deletion was not detected in the rice varieties included in the 3 000 Rice Genomes Project. Thus, the 7-bp deletion identified in the naturally occurring mutant ZXN-E is a novel variation. Our findings suggest that ZXN-E may be a useful germplasm for breeding new rice varieties.