Molecular Basis of Genetic Improvement for Key Rice Quality Traits in Southern China

Abstract

Grain quality is an important indicator in rice breeding, including milling quality (MQ), appearance quality (AQ), cooking and eating quality (ECQ), and nutritional quality (NQ). In this study, we analyzed the variation patterns of 16 traits in 570 rice varieties and found significant improvements in AQ and ECQ in Guangxi rice. Through GWAS and allelic functional nucleotide polymorphisms (FNPs) of quality trait genes, we found that ALK, BG2, FGR1, FLO7, GL7/GW7, GLW7, GS2, GS3, ONAC127, ONAC129, OsGRF8, POW1, WCR1, and Wx were associated with the genetic improvement of rice quality traits in southern China. FNPs analysis of six important rice quality genes, including ALK, Wx, and GS3, were performed using the PARMS method. The results showed that Gui516, Gui569, Gui721, Ryousi, Rsimiao, Rbasi, and Yuehui9802 possessed multiple superior alleles. This study elucidates the phenotypic changes and molecular basis of key quality traits in southern rice varieties.

Keywords: rice, grain quality, GWAS, superior alleles, genetic improvement