Studies on the Characteristics of Scented Rice : XII. Protein content and agronomic characters in F6 and F7 generations derived from Brimful × Koshihikari

[摘要] The purpose of the present investigation was to get the informations on breeding for high protein rice variety. Parents used were a high protein cv. Brimful (Scented rice from Nepal) and a Japanese ordinary rice cv. Koshihikari. A crossing was carried out in 1977. F6 and F7 generations derived from the hybrid were grown in paddy field in 1983 and 1984. Protein and amino acid contents in grains and some agronomic characters were determined. The results summarized as follows : 1. Mean value of protein content in F6 and F7 plants was varied from 10.1% to 12.5% and nearly equal to that in F4 and F5 plants. By examining variance of protein content from F6 and F7 populations, it was shown that they decreased gradually since F6 generation (Tables 1 and 4). The variance was nearly equal to that of cv. Koshihikari. The results showed the tendency of being bred actually connected with high protein content in F7 generation. 2. In F6 generation, although there was a significant negative correlation between protein and ear length, no significant correlation was observed between protein and other agronomic characters (Tbale 2). There was no significant correlation between high protein property and grain yield in F7 plants (Fig.2). 3. In F6 generation, significant differences were observed among plants in lysine and threonine contents per dry weight, and those two amino acids in F6 and F7 generations were much higher than those in cv. Koshihikari (Tables 3 and 5). 4. Significant correlations were observed among protein content and lysine per dry weight in F6 generation (Fig. 1). But, significant correlation was not observed between protein content and lysine content per protein. 5. From the results, it was suggested that high protein content in rice grain could be increased by breeding without decreasing grain yield.

[学科分类] 农业科学（综合）