COMBINING ABILITY ANALYSIS IN F2 GENERATION FOR YIELD AND SOME OF ITS COMPONENTS IN UPLAND COTTON Gossypiom hirsutum L.

Abstract

Cotton varieties, Halab1, SP8886, Coker5114, Deltapine5409, Lachata, Dunn1047 and Deer22, and all their F2 half diallel crosses were planted at field of Agriculture and Forestry college (Center of Mosul university) in May, 4, 2006 using randomized complete block design with three replications to study general and specific combining abilities for parent and crosses respectively, phenotypic variance components and some genetic parameters for characters: plant height, number of vegetative and fruiting branches, number of bolls per plant, boll weight, seed and index indices and seed cotton yield per plant. Analysis of variance results showed that mean square of genotypes, general and specific combining ability was significant for all characters. The variety Halab 90 appeared as a good general combiner, and (SP8886 x Coker5114), (SP8886 x Deltapine5409) and (Coker5114 x Deer22) crosses as good specific combiners for largesr number of characters. The total genetic variance was high as compared with environmental variance for plant height and number of fruiting branches, and the reverse for the remainder characters. Broad sense heritability ranged from 24.051% for seed cotton yield per plant and 71.101% for plant height, and it was high for plant height, number of fruiting branches and lint index, moderate for number of vegetative branches and boll weight, and low for number of bolls, seed index and seed cotton yield per plant. It was shown that selection for plant height gave higher percent of response to selection (5.275%) from original mean of yield, followed by number of bolls which gave percent of response to selection (2.783%) from original mean of yield.