香り米の特性に関する研究 : 第10報 高たんぱく性品種育成の試み (2)

抄録

A cross between Brimful from Nepal (a scented variety with high protein) and Nippon bare (a Japanese rice variety) was carried out in 1977 and F₂-F₅ plants were grown from 1978 to 1982. The present experiment was conducted for getting the informations on breeding of rice variety with high protein. The results obtained are summarized as follows : Grain protein content in F₂ and F₃ plants showed wide and continuous distributions. Mean of F₂ plants was located between P₁ (high protein parent) and P₂ (low protein parent) and slightly lower than the mid parent (Figs. 1, 2). The narrow sense heritability of protein content based on the variance and co-variance of F₂ and F₃ plants was O.588. As concerns protein content and agronomic characters, result of F₅ plants did not show significant correlation except one line (Table 8). These results indicated that it was possible to select promising lines having high protein property and desirable agronomic characters. As compared with F₃ and F₄ generations, F₅ was high in mean value of protein content and also decreased in the genetic variance of protein one (Tables 1, 2, 7). High protein property showed the tendency of being bred in true in F₅ generation. As for amino acid contents in F₄ and F₅, there were significant differences among the lines in three amino acids per dry weight basis, not per protein basis, and the lines were far better in the trait than Nippon bare (Tables 4, 9). Significant correlation was observed between protein content and lysine and threonine per dry weight in F₄ and F₅ plants (Tables 5, 10). The promising lines which have high protein property and also relatively good agronomic characters were selected based on thc measured results in F₅ plants (Table 11).