Effect of temperature during grain development on stability of cooking quality components in rice

Abstract

Thirty one rice varieties representing five amylose categorles were grown under four different controlled temperature conditions in the IRRI Phytotron to stucly the effect of temperature during grain development on the amylose content, gelatinization temperature, and gel consistency. Stability analysis revealed predominance of linear component of variety-temperature interaction for all the three components. In general the amylose content decreased with increasing temperature. All the variety in the waxy group and majority of those in high amylose group showed absence of variety-temperature interaction for amylose content. Varieties in the very low, Iow and intermediate categories were either responsive or unstable. Similarly for gelatinization temperature and gel consistency also a number of varieties showed absence of interaction with temperature, some were responsive and others unstable. Waxy varieties IR29 and Malagkit Sungsong and high amylose variety IR42 were found to exhibit no interaction with the temperature for all the three quality components. Implications of the study on breeding strategy are discussed.