Abstract :
A complete diallel cross of nine cotton genotypes (Gossypium hirsutum L. & Gossypium barbadense L.) viz
Delinter, Sindose-80, Omoumi, Bulgare-539, Termez-14, Red leaf (Native species), B-557, Brown fiber and
Siokra-324 having diverse genetic origins was conducted over two years to determine the potential for the
improvement of yield, its components, oil and fiber quality traits by means of genetic analysis, combining
ability, heritability and heterotic effects. The detailed studies were based on F1 generations where crossed seeds
in the first year were used for F1 generation in the second year. The successful hybrids were recognized and
distinguished by morphological markers such as flower color, spot position and their colors in petal, fiber
color, seed linter, leaf color and their shapes. Analysis of variance for Simple Square Lattice Design (SSLD)
showed highly significant differences (P ? 0.01) among various genotypes which allowed genetic analysis by
Griffing, Hayman and Hayman-Jinks, method. Additive- dominance model and related correlation (Wr, Vr)
were adequate for majority of the traits and partially adequate for some traits. Majority of the traits were
influenced by non-additive gene action in F1 generation. These results are encouraging for practical
improvement through hybrid breeding programs and the contributions of additive genes through selection
method. Significant variation for general combining ability (GCA) effects, specific combining ability (SCA)
effects (P ? 0.05) and high narrow sense heritability indicates the potential for improvement through selection.
On the other hand, over-dominance gene action, low and moderate rate of narrow-sense heritability for some
traits suggests that improvements should be made utilizing a combination and hybrid breeding approach.
