EVALUTION OF HETEROSIS IN FIVE SETS OF DESI COTTON HYBRIDS

Abstract

Sixty eight dcsi cotton hybrids were developed by crossing 30 genotype.~ selected from five groups of Gussypium arboreum races benga1ense and indicum and G. herbaceum. In each group, IS hybrids were created by diallel mating (without reciprocals). Interspecific crosses between two varletics each of G. arboreum races benga1ense and indicum were also made with. two G. herbaceum strains obtaining eight hybrids. Studlcs Indicated that interspecific crosSlS exhibited higher magnitude of useful heterosis for seed cotton yield as compared to the intra racial hybrids tested in four groups. Negative heterosis for ginning out turn and halo length was shewn by interspecific crosses. Intra racial hybrids of red x red (G. arboreum race benga1ense) varieti.cs also expressed higher magnitude of heterosis effect for seed cotton yield. Dwarf x dwarf hybrids expressed high heterosis for yield and halo length, but negative heterosis for ginning out turn. Crosses within the race indicum registered ~bstantial heterosis for all characters under study.