Balancing High Yield and Superior Eating Quality: Insights From Starch Structural and Thermal Properties in Hybrid...

The development of rice varieties that combine high yield with superior eating quality constitutes a critical objective in agricultural production. This study aimed to elucidate the structural and thermal properties of starch that simultaneously contribute to high yield and good taste by systematically comparing grain yield, cooked rice taste, and starch fine structure among three types of rice varieties: high yield and good taste variety Rong18you2348 (R2348), high yield and poor taste variety Fyou498 (F498), and low yield and good taste variety Fengyouxiangzhan (FYXZ). The findings indicated that R2348 achieved an optimal balance between yield and eating quality through a unique starch architecture. Specifically, compared to F498, R2348 demonstrated a 30.52% reduction in amylose content and a 4.14% increase in the proportion of short-chain amylopectin (A chains), along with more regular starch granule surfaces. Compared to FYXZ, R2348 exhibited a relatively higher proportion of short A chains, a 6.42% increase in branching degree, and a higher molecular weight of starch. The analysis of the Rapid Visco Analyzer (RVA) profile had determined that a high peak viscosity, coupled with a high breakdown value and a low setback value, represented the fundamental starch physicochemical property linked to superior eating quality. Further correlation analysis demonstrated that optimizing the molecular weight distribution ratio (Mw/Mn) and reducing the gelatinization temperatures (T_p and T_c) were crucial for balancing grain yield and eating quality. This study elucidates that the targeted regulation of starch structure and RVA profile characteristics offers an effective strategy for breeding indica hybrid rice varieties that successfully integrate high yield with excellent eating quality.