Abstract
In order to clarify the inheritance of numbers of large vascular bundles in peduncle (Vb). primary rachis branches (Rb), and the ratio of Vb to Rb (V/R ratio), F_2 and F_3 progenies derived from the cross of Indica and Japonica (Milyang 23×Akihikari) were investigated. An F_2 population of Indica Japonica hybrid showed continuous variation in all traits, this suggesting that these traits were controlled by some major genes or polygenes. The narrow-sense heritabilities for Vb, Rb and V/R ratio were 0.593, 0.530 and 0.367, respectively, all of which seemed to be relatively high heritability among the quantitative traits in cultivated rice. Heritabilities of broad-sense in Vb, Rb, and V/R ratio were also estimated from the variance analysis of 10 cultivars of different ecotypes of Asian rice. High heritabilities as to be 0.784, 0.887 and 0.922, respectively, were obtained.
