Determination of superior parents and hybrid combinations resistant to drought stress in cotton breeding

This study was conducted in randomized complete blocks with three replications to investigate the genetical make up, evaluate F, hybrid vigor and determine the suitable parents and their hybrid combinations for studied characteristics in the population obtained by Line x Tester quantitative analysis method involving 5 female and 3 male parents of cotton (Gossypium hirsitum L.) in the Southeast Anatolia Agricultural Research Institute experimental area, in the years of 2001-2002. In the populations; plant height, leaf area, number of monopodial branches, number of sympodial branches, number of bolls, seed cotton yield, first picking percentage, fiber fineness, fiber length, fiber strength and fiber elongation properties were influenced by additive; boll weight, seed cotton weight per boll, ginning percentage and 100 seeds weight was influenced by non-additive gene effects. Values of heterosis for number of monopodial branches, first picking percentage, fiber fineness and fiber elongation were negative, while the other characters were positive. It was determined that Stoneville 453 and Cabu CS 2-1-83 for plant height, Kurak 2 for leaf area, Cabu CS 2-1-83 and Blightmaster for number of monopodial branches, Stoneville 453 for number of bolls, Blightmaster for seed cotton yield, Maraş 92 and Cabu CS 2-1-83 for first picking percentage, Erşan 92 for ginning percentage, Sicala 33 for fiber length and fiber strength, Blightmaster for fiber elongation were the best parent cotton cultivars and also having best general combining abilities. It was determined that Tamcot CD 3H x Stoneville 453 and Cabu CS 2-1-83 x Stoneville 453 for plant height, Blightmaster x Erşan 92 for leaf area, Cabu CS 2-1-83 x Maraş 92 for number of monopodial branches and'fiber elongation, Kurak 2 x Maraş 92 for number of sympodial branches, Blightmaster x Stoneville 453 for number of bolls and seed cotton yield, Blightmaster x Maraş 92 for first picking percentage, Tamcot CD 3H x Erşan 92 for ginning percentage, Tamcot CD 3H x Stoneville 453 for fiber fineness, Tamcot CD 3H x Maraş 92 for fiber length, Sicala 33 x Stoneville 453 for fiber strength hybrid combinations were the most promising crosses. Key Words: Cotton, drought stress, general and specific combining ability, heterosis.