Variations in Pasting Properties of High‐Quality Hybrid Rice and Their Relationships With Amylose and Protein Contents: A Pooled Analysis of 543 Observations

Abstract

Numerous high‐quality hybrid rice varieties have been developed in China to satisfy the increasing demand for superior grain quality. To determine variations in four key pasting properties—peak viscosity, breakdown viscosity, setback viscosity, and pasting temperature—and evaluate their relationships with amylose and protein contents in high‐quality hybrid rice, this study pooled and analyzed 543 observations from 8 field experiments conducted in Hunan Province, China. Setback viscosity showed the highest variability (coefficient of variation [CV] = 35%), followed by breakdown viscosity (CV = 18%) and peak viscosity (CV = 16%), while pasting temperature exhibited the lowest variability (CV = 4%). Linear regression analysis demonstrated that both peak and setback viscosities were significantly associated with amylose and protein contents, whereas breakdown viscosity and pasting temperature were significantly related only to amylose content. Dominance analysis further revealed that protein content had a greater influence on peak viscosity, while amylose content played a more important role in determining setback viscosity. Among the four evaluated pasting parameters of high‐quality hybrid rice, setback viscosity exhibited the highest level of variability, followed by breakdown viscosity and peak viscosity, whereas pasting temperature showed the smallest degree of variation. With respect to the contributions of amylose and protein contents to these variations, protein content had a stronger influence on variation in peak viscosity, whereas amylose content played a greater role in shaping the variability of the remaining three pasting parameters. This study clarifies the relative variability of four key pasting parameters and provides guidance for selecting compositional targets—namely, amylose and protein contents—for improving these pasting characteristics in high‐quality hybrid rice.