Abstract
Genetic analysis of the morphology of silica bodies from motor cells in rice (Oryza sativa L.) was conducted by examining an F2 population and a set of 3×5 NCII diallel crosses. Segregation for the four morphological characters-vertical length, horizontal length, Iateral length and shape coefficient (b/a)-of silica bodies in the F2 population showed a countinous and a wide distribution exceeding the ranges of the two parents (Fig.2), suggesting that the morphological characters of silica bodies were quantitative and controlled by several genes. In the NCII diallel analysls, the heterogenelty of W'r+1/2Vr between arrays was not significant for all the morphological characters but b/a, and the heterogeneity of W'r-1/2Vr was not observed for all the characters tested (Table 4). The regression coefficients of W'r on Vr were nearly 0.5 but significantly different from zero (Table 5), indicating that the shape of the silica bodies was controlled by an additive-dominance genetic system. The heritabilities in a broad sense for the four characters were in the range of 0.43-0.73 and those in a narrow sense in the range of 0.29-0.54 (Table 6).
