GENETIC ARCHITECTURE IN MAIZE (ZEA MAYS L.) USING HALF DIALLEL PATTERN

The study included seven pure lines of maize, Ma-F53, Sy-F-54, H-4, ZP-595, Pol-F-6, Zp-607 and DKC-F-59. The half diallel crosses were made among them to obtain 21 single crosses. The 7 parents and 21 F-1's were planted during the autumn season of 2021 in a farmer's field at Al-Rashidiya, Nineveh Governorate, using Randomized complete block design with three replications. The data were recorded on the traits of number of days to tasseling, number of days to silking, plant height, upper ear height number of rows per ear, ear length, ear diameter, number of grains per row, 500 grains weight and grain yield per plant. The results showed that the mean square of genotypes, parents, crosses, GCA and SCA were highly significant for most traits including grain yield per plant. The three pure lines H-4, Pol-F-6 and Sy-F-54 had significant desirable general combining ability effects for the largest number of traits, and the hybrids showed variations in their SCA for different traits, as hybrids (1.4) and (4.5) and (2.6) were characterized by significant desired SCA for the largest number of traits, including grain yield of the plant. The values of dominant genetic variance were greater than those of the additive for all traits, and the average degree of dominance was less than one for all traits indicative of over dominance. The broad sense heritability in the ranged from 30.92% for number of rows per ear and 99.42% for plant height, and it was low for number of rows per ear and high for all other traits, while the narrow sense appeared low for all traits and ranged from from 5.62% for number of rows per ear and 18.08% for plant height.