A comparative study of heterosis in GMS based and conventional intra Arboreum cotton hybrids

A comparative study of heterosis over better parent was carried out during 1995 in GMS based and corresponding conventional hybrids, which were generated by utilising two genetic male sterile lines viz. DS-5 and GAKA-423 and their male fertile counter lines as female parents respectively. The GMS based hybrids exhibited high heterosis over better parent for seed cotton yield and its component characters compared to conventional hybrids. The high yielding GMS based crosses showed simultaneous heterosis for seed cotton yield and its component characters like number of bolls/plant, boll weight and number of seeds/boll. However the GMS based hybrids failed to exhibit heterosis over better parent for ginning out tum except one cross, as against three conventional hybrids. The higher ginning out-tum of conventional hybrids was mainly contributed by their lower seed index values, as large proportion of conventional hybrids exhibited negative heterosis for seed index. Three GMS based hybrids viz., DS-5 x 30802, DS-5xNo.2631 and DS-5 x B-Desh are potential hybrids for exploitation of hybrid vigour ulilizing DS-5 male sterile line.