Abstract: Agronomic traits and rice quality of a partial palea mutant induced by irradiation from a japonica rice variety ‘Zhejing 22’ were studied. The results showed there was no difference in plant height and ear length in comparison to its wild type, but there were significant decreases in per panicle, filled grain number per panicle, 1000-grain weight and second panicle branch, which were about half of the wild type. There was a clear decrease in grain width for mutants and little difference in grain length, and the length-width ratio of ‘Zhejing 22’ was 2/3 of the mutant. Chalk percentage and chalkiness degree of the mutant were good, while brown rice rate, milled rice rate and head rice rate was little different from the wild type. The mutant also showed lower RVA profile characters of PKV (peak viscosity), HPV (hot paste viscosity), CPV (cool paste viscosity), SB (setback), and CS (consistency)than ‘Zhejing 22’, meanwhile, the amylose content of the mutant increased.

Key words: palea mutant, rice grain, quality, RVA