Abstract: An additivedominant genetic model with genotypeenvironment(GE) interaction was employed to heterosis analysis of head weight, head diameter, head height, maturity, plant height, plant spread width and leaf number in cauliflower, based on 2year data from 6×6 diallel crosses. The results indicated that the effect of environmental deviation of different years on agronomic traits of parents and F1 was less. The correlation between mean values of agronomic traits in F1 and parents mean values were significant. These traits could be improved by selection in early generations for head weight, head diameter, head height and maturity which were mainly affected by additive effects. However, the selection effects were prone to be affected by the dominance effects and genotype×environment interaction effects for plant height, plant spread width and leaf number. Therefore the improvement effects would be better for these traits by conducting selections in advanced generations. The total heterosis of head weight, plant height, plant spread width and leaf number was positive value and maturity was negative value for improvement of these traits breeding in cauliflower. There was only genotype×environment interaction heterosis detected for head diameter, the selection effects were easily affected by the various environments. There was no heterosis detected for head height.

Key words: cauliflower (Brassica oleracea L. var. botrytis L.), agronomic traits, heterosis, genotype, environment interaction effects