Comparative performance of superior and inferior grains for quality parameters following diversified temperature during grain filling stage

The responses of rice quality including milling, appearance, and eating quality between superior (SG) and inferior grains (IG) to temperature during grain filling stage (TGF) remained poorly understood, especially for eating quality. Therefore, the regulation of TGF (17.6-30.4 degrees C) on quality of three indica hybrid varieties (IHs) was investigated by setting multiple sowing dates and the mechanism underlying taste difference was explored by monitoring chemical compositions, rapid visco analyser (RVA) profiles, and texture properties. Results suggested that TGF ranging from 23.3 to 25.2 degrees C could comprehensively improve the milling, appearance and eating quality of IHs, and the optimal TGF of SG was 2.3-4.2 degrees C lower than that of IG. Compared with chemical compositions and RVA profiles, texture properties were better for evaluating the eating quality of IHs. When TGF was higher than 24.0 degrees C, the taste value of IG was higher than that of SG mainly due to higher elasticity. The findings indicate that TGF had differential regulatory effects on SG and IG, which could provide a useful reference for cultivation of high-quality rice varieties under global climate change. Besides, the determination of texture properties was a reliable method for taste evaluating of IHs in the breeding process.