Comparison and Heritability of Major Rice End-Use Quality Traits Among Diverse Accessions Grown in Both Tropical and Temperate USA Environments and Genetic Marker Implications.

Growing environment has been well-documented as playing a large role in effecting the end-use quality traits of rice. Apparent amylose content (AAC) and gelatinization temperature (GT) are considered to be the two most important end-use quality characteristics in rice, defining the major classes that rice is sold within domestic and international markets. We analyzed the levels of these two quality characteristics among a set of genetically diverse accessions of rice grown in two vastly different US rice production environments. Ninety diverse accessions of rice were grown for two seasons in both Texas and California, and AAC and alkali spreading values (an indirect measurement of GT) were measured on mature grain. Analysis of variance results indicated that these two end-use quality measurements had very high heritability levels, despite the large differences in growing environments. DNA markers located at the Waxy and Alk genes explained a large majority of the variation in these traits, indicating their usefulness to predict AAC and GT in a broad expanse of germplasm and production environments.