放射線에 의한 水稻의 蛋白質育種

Studies on the Mutation of Rice Protein

The studies were carried out on change of protein content of high protein mutants under different cultivation conditions, correlation between protein content and agronomic characters of mutant lines, and other related works. As for the influence of sowing date, mutants behaved variously showing no definite tendency, and variation was wider than that of the mother varieties. In the mutants and their mother varieties alike, the tendency of variation of protein under different planting spaces was uniform, and the variation was not large in mutants as well as in their mother lines. Among the high protein mutant lines grown under different cultivation conditions, no correlations were found between protein percent and panicle number per unit area, between protein percent and grain size, and between grain size and protein amount per grain. In relation between protein content and some agronomic traits, there were correlations between culm length and protein, grain weight and protein content, culm length and grain weight, and between grain weight and protein per seed. High protein mutants were attributable to the corresponding increase of glutelin fraction which accounted for more than 70% of protein. Usually high protein mutant lines had lower basic amino acids per gram protein than low protein lines when estimated by DBC.