Improving grain quality alongside yield remains a primary objective in rice breeding, especially under irrigated systems in Thailand, where consumer demand for soft-textured, premium table rice continues to grow. This study evaluated physicochemical and pasting characteristics of ten advanced non-glutinous rice genotypes compared with high- and low-amylose checks across three irrigated environments during off-season 2024. Combined ANOVA revealed highly significant genotype, environment, and genotype × environment interaction effects, with genotypes contributing up to 94.30% of total variation for key quality traits. Grain breadth and elongation rate were predominantly influenced by environmental conditions. Principal component analysis showed that PC1 and PC2 explained 72.86% of total variance, separating genotypes based on amylose-driven starch properties and paste stability. High-amylose genotypes exhibited low peak viscosity and high setback, whereas low-amylose genotypes showed greater swelling, higher breakdown, and softer pasting behavior. Selected genotypes exhibited distinct quality profiles; specifically, DS24-Inter-8 and DS24-Inter-10 combined low-to-intermediate amylose (15.09–19.73%) with high gel consistency (84.78–96.22 mm). Interestingly, DS24-Inter-4 maintained high gel consistency (97.78 mm) despite a higher amylose content (26.39%), indicating a unique soft-cooking profile for high-amylose types. In contrast, DS24-Inter-7 and DS24-Inter-9 showed typical firmer, high-amylose characteristics. These contrasting quality profiles indicate that the genotypes were suitable for different utilization purposes depending on the desired physicochemical and textural attributes. Therefore, the advanced genotypes demonstrated stable and diverse quality profiles under irrigated conditions, warranting further multi-location and multi-season evaluation.
Teanthong et al. (Tue,) studied this question.