抄録
1. This work is one of the studies in which the writers intend to make clear the mode of quantitative inheritance in main crops from the view ppint of breeding. Materials used are the same as those used for the studies of inheritance of the panicle length and culm height in the preceding experiments(SYAKUDO, et. al. 1952-a, b) namely -, the F1-F4 generations from the hybnds of "NABESIMA" and "KAlRYO-AIKOKIJHEN-DAIKOKUGATA", which were crossed in 1945 at the plant-breeding laboratory of the Kyoto Univ. The total numbers of lines and individuals ob, served are 467 and 49, 223 respectively. 2, , NABESIMA" is a normal variety showing a medium length of panicles and a medium height of culm with small grains, three dimensions of which are about 5.3mm, 3.0 mm, and 2.1 mm. "KAIRYO-AIKOKUHEN-DAIKOKUGATA" is a dwarfish variety with short panicles, short culm and small round grains, three dimensions of which being 4.5 mm, 3.2 mm and 2.3 mm. 3. The conditions of cultivation and the methods, of investigation are the same as those already, described in the writer's reports (SYAKUDO, 1948-b, 1951). . 4. The progeny test in regard to the grain length was made considering the mean value, standard deviatian, coefiicient of variabilityand the range of variance. The results show that the gene Gr3 and the dwarfish gene D1 determine the grain length. Thus the genotypes of the parents will be assumed as follows:
