摘要
Appearance and cooked rice elongation are key quality traits of rice. Although some QTL for these traits have been identified, understanding of the genetic relationship between them remains limited. In the present study, large phenotypic variation was observed in 760 accessions from the 3 K Rice Genomes Project for both appearance quality and cooked rice elongation. Most component traits of appearance quality and cooked rice elongation showed significant pairwise correlations, but a low correlation was found between appearance quality and cooked rice elongation. A genome-wide association study identified 74 QTL distributed on all 12 chromosomes for grain length, grain width, length to width ratio, degree of endosperm with chalkiness, rice elongation difference, and elongation index. Thirteen regions containing QTL stably expressed in multiple environments and/or exerting pleiotropic effects on multiple traits were detected. By gene-based association analysis and haplotype analysis, 46 candidate genes, including five cloned genes, and 49 favorable alleles were identified for these 13 QTL. The effect of the candidate gene Wx on rice elongation difference was validated by a transgenic strategy. These results shed light on the genetic bases of appearance quality and cooked rice elongation and provide gene resources for improving rice quality by molecular breeding.
基金
funded by the National Key Research and Development Program of China (2016YFD0100301)
Project for Cultivating New Transgenic Varieties (2016ZX08009003-004)
the Agricultural Science and Technology Innovation Program and the Cooperation and Innovation Mission (CAAS-ZDXT202001)
Open Fund of Hubei Collaborative Innovation Center for Grain Industry (HCICGI2020-06)
the National Natural Science Foundation of China (U19A2025 and 31870229)。
