THE GENETIC SYSTEM CONTROLLING AGRONOMIC TRAITS IN CANOLA

To determine the types of combining abilities, heterosis and genetic behavior of agronomic traits, six divergent canola genotypes were crossed using a half diallel mating design (excluding reciprocal crosses). The parents and their crosses were evaluated using a randomized complete block design with three replicates at Kafr-El-Hamam/Sharkia and Etay-El-Baroud/Behaira Agricultural Research Stations, Agricultural Research Center, Egypt. The preponderance of dominance gene action was observed for most studied traits as verified by the average degree of dominance and narrow-sense heritability. The GGE biplot revealed that N.A.36 and N.A.39 at Kafr-El-Hamam and N.A.39 and N.A.14 at Etay-El-Baroud were the best general combiners for seed weight plant-1 and N.A.36, N.A.38 and N.A.39 at Kafr-El-Hamam and N.A.36, N.A.39 and N.A.14 at Etay-El-Baroud for seed oil content, which associated with proportion of desirable genes either dominant or recessive. Superior crosses than better parents for seed weight plant-1 were observed in four crosses [N.A.36 and N.A. 37] x [N.A.38 and N.A.14] at Kafr-El-Hamam and two crosses [N.A.37] x [N.A.38 and N.A.14] at Etay-ElBaroud as well as for seed oil content in four crosses [N.A.39 and N.A.14] x [N.A.37 and N.A.38] at Kafr-El-Hamam and two crosses in [N.A.18] x [N.A.37 and N.A.38] at EtayEl-Baroud.