Starch and protein physicochemical properties associated with rice taste quality across Wx alleles under different cultivation practices.

Abstract

The Wx gene plays an important role in rice taste quality through its regulation of amylose biosynthesis. However, whether quality differences associated with distinct Wx alleles remain consistent under cultivation practices remains unclear. Six rice lines carrying different Wx alleles were evaluated under nitrogen fertilization and sowing date treatments, while four representative lines (wx, Wxmp, Wxb, and Wxlv) were further assessed under water management treatments. Amylose content ranged from 2.20% to 31.26%, forming a continuous gradient associated with grain composition, physicochemical properties, and taste quality. Low-amylose genotypes showed lower hardness, higher stickiness, and higher taste values than high-amylose genotypes. Taste quality variation was associated with starch crystallinity, retrogradation tendency, swelling behavior, RVA characteristics, and protein properties. Cultivation practices modified quality-related traits, while patterns among Wx genotypes remained consistent across conditions. Overall, Wx allelic variation was associated with rice taste quality variation through differences in amylose accumulation and physicochemical properties.