Abstract
Selection response and correlation response of the frequency of hull-cracked grains and the 1, 000-grain weight were investigated for analyzing the mode of inheritance and genetic correlation of the traits. In the first experiment, upper 5% and lower 5 % of the four F2 populations were selected for the frequency of hull-cracked grains and the selection response was examined in F3 progenies. In the second experiment, the frequency of hullcracked lgrains and l, OOO-grain weight of 183 F2 plants from the cross of Nittakei 2Z X Yoshikei 16 were recorded and 183 F3 Iines were grown to estimate the parent-offspring correlation and regression. In the third experiment, environmental correlation between the frequency of hull-cracked grains and the 1, 000-grain weight was estimated from 50 plants each of Nittakei 2Z and Yoshikei 16. The materials were seeded twice in November and December.
