Abstract
Seven upland cotton varieties (Halab09, SP8888, Dunn5151, Coker1555, Lachata, Dunn5951 and Coker059) were used in half diallel cross to develop 15 single crosses. Parents and their crosses were sown at Al-Haweja (Kirkuk Governorate) in 19 April 1991 using randomized complete block design with three replications. Graphic analysis, components of genetic variation and narrow sense heritability were estimated for characters: plant height, number of vegetative branches, number of fruiting branches, number of bolls per plant, boll weight, seed index, lint index and seed cotton yield per plant. The results showed highly significant differences between genotypes for all characters. Additive and dominance genetic variance components were significant from zero for all characters. The values of dominant components were more than that of additive for all characters except for boll weight. Graphic analysis suggested the presence of epistatic gene action (non-allelic interaction) for plant height, boll weight, seed index, lint index and seed cotton yield per plant. Narrow sense heritability was high for seed cotton yield per plant (8575156), moderate for number of vegetative branches, boll weight and seed index, and low for other characters.
Main Subjects