抄録
1. This work is one of the studies in which the as followswriters intend to make clear the modes of the quantit, ative inheritance in main crops from the view point of breeding. Materials used in this work are the F1-F5 generations from the hybrids of the two varieties, of rice, "NABESIMA" and "KA1RYo-AIKoKUnEN-DAIKO-KUGATA", which were crossed in 194 at the Plantbreeding laboratory of the Kyoto Univ . The total :numbers of the lines and individuals observed are 1. 137 and 85.616 respectively. 2., 'NABESIMA" is a normal veriety showing a medium stem length and also a medilm length of pa nicles (about 21 cm), while "KAlRYO-AIKOKUHEN-DAIKOKUGATA" is a dwarfish variety with short stems and short penicles (about 17 cm). 3 . The methods of investigation are the same as those already described in the senior writer's previous feports (SYAKUDO, 1948, 1950). 4, The progeny test in regard to the. panicle length was made eonsidering the mean value, standard deviation, coeificient of variability and the range of variance. The. results ., show that the two multiple, genes P4 and P5., and a dwarfish gene D1 determine the panicle length. The accumulative effect of the genes P4 and P5 to the panicle length are of inperfect dominance, while that of D1 is of perfect dominance. Consequently the genotypes of the parents will be assumed as follows:
