Abstract

                                A four parent full diallel analysis was made in Gossyplum barbadense cotton to study the nature of general and specific combining abilities and the magnitude of relative heterosis for yield of seed cotton, halo length and ginning outturn. Yield of seed cotton was predominantly under the control of dominance gene action where as halo length and ginning were predominantly under the control of additive gene action. TCB 295 was the best combiner for halo length and TCB 296 was the best combiner for ginning outturn. Heterosis for seed cotton yield ranged from 18.11% to 90.64% while the magnitude of heterosis was low in respect of halo length and ginning. The hybrid combination TCB 293 x TCB 296 was suggested for exploiting through heterosis breeding for increasing the seed cotton yield.

Key words : Cotton, Combining ability, Heterosis.