Combining ability studies for seed cotton yield in intraspecific hybrids of upland cotton (Gossypium hirsutum L.)

Thirty-two hybrid combinations were obtained by crossing four lines with eight testers in L x T fashion and F₁'s along with their parents were used for assessing combining ability for different yield and fibre quality traits. Variance due to parents and hybrids showed significant differences for all the characters studied except for the number of monopodia, boll weight and elongation percentage. Variances due to GCA were larger than SCA for all the traits, indicating the preponderance of dominance gene action. The lines, TSH 0499 and TSH 04/115 and the testers, MCU 13 and TCH 1819 which registered high per se performance coupled with the significant GCA effect were identified as best parents in developing hybrids with improved yield and fibre quality traits. The hybrid combinations viz., TSH 04/115 x MCU 7, TSH 0499 x SVPR 4, TSH 0499 x TCH 1819, TSH 0499 x MCU 13 and TSH 04/115 x TCH 1819 which showed significant sca could be used in heterosis breeding programme for improvement of both yield and fibre quality traits.