Effect of genotype × environment interactions on starch physicochemical properties in diverse sorghum germplasm

Genotypic diversity and genotype-environment (G × E) interactions affecting starch quality parameters were investigated in 28 sorghum genotypes over two growing seasons. Starch granule diameter ranged from 3.22 to 29.20 μm. Amylose content effectively distinguished waxy genotypes (~5%) from non-waxy (~20–33%) genotypes. Starch phosphorous content ranged widely from 109.26 to 618.06 ppm in environment 1 (E1) and 106.94 to 1753.24 ppm in environment 2 (E2). Starches in E1 had higher gelatinization temperatures but lower enthalpy than those in E2. Dynamic rheological analysis indicated that all starches displayed elasticity-dominated, weak-gel behavior, while steady-shear analysis showed consistent shear-thinning behavior with a flow index <1. Principal component analysis of starch quality parameters revealed 60.0% and 61.9% of total variance for E1 and E2, respectively. In addition, correlation analysis further highlighted a significant negative association between amylose content and crystallinity, thermal/retrogradation properties, and shear-thinning behavior across both environments. G × E results also showed significant impact of growing conditions on sorghum starch phosphorus levels, pasting and thermal properties. Together, these findings provide a foundation for developing improved sorghum cultivars tailored to food and industrial applications. • Waxy sorghum had ~5% and non-waxy had 20–33% amylose content. • Sorghum starch has A-type crystalline pattern with waxy starch showing higher relative crystallinity. • Starch phosphorus content varied widely by environments, ranging from 106.94 to 1753.24 ppm. • Amylose content had a negative correlation with crystallinity, thermal/retrogradation properties. • G × E results also showed significant impact of growing seasons on sorghum starch phosphorus levels, pasting and thermal properties.