Heterosis for Yield and its Component Characters in Boll Worm Tolerant Gossypium Hirsutum L. × G. Barbadense L. Cotton Hybrids

With the objective of reducing cost of cotton cultivation, five boftworm and aphid tolerant (JK-344, JK-345, JK-260, JK-276 and MESR-17) and one susceptible cv. S43 (Sharada) of Gossypium hirsutum L. were crossed with one bollworm tolerant (B 200-82-1) and two susceptible (SB-289E and SB(YF)-425) G. barbadense genotypes. Hybrids or JK-276 and MESR-17 with B 20O-U2-I exhibited higher heterosis of 51 and 47%, respectively, for yield/plant over DCH-32. Yield increase was mainly due to significantly lower heterosis for number of bollworm damaged bolls as well as higher heterosis for number of bolls/plant. B 200-82-1 is a better and normal branching general combiner than the established cluster flowering genotypes SB-289E and SB(YF)-425. Yield and bolls per plant are controlled by nonadditive gene action, monopodial and sympodial branches by partial dominance, and boll weight by additive gene action. Hybrids JK-276 × B 200-82-1 and MESR-17 × B 200-82-1 should be tested in multilocation trials to identify a superior hybrid requiring low cost of cultivation.