Accumulation Characteristics Of Protein And Non-Protein Components And Their Correlations With Protein Concentration In Rice Grains

Protein in rice grains is an important source of nutrition for rice consumers. This study mainly aimed to identify the critical factors that determine grain protein concentration in rice. Accumulation parameters, including mean accumulation rate (R-mean) and active accumulation duration (D-active), for protein and non-protein components and their correlations with protein concentration in rice grains were investigated in field experiments conducted over two years with six rice cultivars. Results showed that grain protein concentration ranged from 9.6% to 11.9% across cultivars and years. Accumulation processes of protein and non-protein components were well fitted by the logistic equation for all six rice cultivars in both years, and the ratio of protein to non-protein for R-mean and D-active ranged from 0.08 to 0.12 and 1.01 to 1.33, respectively. Grain protein concentration was significantly correlated with protein to non-protein ratio for R-mean. This study suggests that grain protein concentration is not solely determined by the accumulation of protein or non-protein component, but by the coordination of protein and non-protein accumulation.