Studies on Breeding for High Protein Rice : II.Inheritance of the High Protein Property in a Japonica Rice Cross

Abstract

The high protein property of a Japanese rice variety "Fukunishiki" was studied geneti cally and genealogically. Inheritance of the high protein property was investigated by the use of the F₂ hybrid population derived from the cross of the high protein variety "Fukunlshlkl" wlth a low protein one "Fujimlnori". The F₂ population mean as well as the F₁ mean fell on between the low protein parent and the mid-parent values. A monomodal, symmetrical distribution was observed in the F₂ segregation of protein content (Fig. 1). The broadsense heritability of protein content was computed based on the genetic variance of the F₂ hybrid population and the estimated value 0.45 was obtained. The F₂ to F₃ and F₃ to F₄ parent-offspring correlations for protein content were 0. 551 and 0. 709 respectively, both of which were statistically slgnificant at the 1% Ievel (Fig. 3, and Fig. 4). Regarding to the relatios between the protein content and the other agronomic traits, negative correlations were predominantly observed in F₂ through F₄ generations derived from the above-mentioned cross. Early, short-statued, and poor-yielding segregants tended to be rich in protein (Tabe 1).