Abstract

                                A ten parent diallel cross analysis involving bollworm tolerant donor lines of upland cotton was studied for component of variance analysis for seven traits. Both additive and non-additive gene action were important for all the traits except seed index. However the role of dominance was major for all the traits studied. Dominance was ambidirectional for all the traits studied. Epistasis influenced the performance of number of bolls and seed cotton yield. Narrow sense heritability was high for days to 50 per cent flowering, boll number and seed cotton yield/plant while moderate for boll weight, seed index, lint index and ginning percentage. The number of genes controlling inheritance of the traits were established. Any form of recurrent selection may be followed for exploiting all the three types of gene actions.

Key words : Diallel analysis, upland cotton, heritability, genetic components, bollworm.