COMBINING ABILITY OF YIELD AND YIELD COMPONENTS IN UPLAND COTTON (G. hirsutum L.) GENOTYPES UNDER NORMAL AND WATER-DEFICIT CONDITIONS

Cotton is considered as the main crop in the agricultural sector of Uzbekistan. Water deficiency in the Central Asian region in recent years have reduced the chances of high yields of cotton. Selection and creation of high-yielding varieties of cotton, even in drought conditions, is one of urgent tasks of today. Therefore, in optimal conditions with sufficient water and in water stress conditions, the combined ability of Omad, Ishonch varieties, L-490, L-501, Determinant-2, Determinant-3 lines, their F1 hybrids of G. hirsutum L. cotton in terms of productivity and productivity components was determined. In this case, average indicators of seed yield, single boll weight, 100 seed weight, lint percentage and lint index traits in all the studied genotypes under water stress condition were noted to decrease in different extent compared to optimal irrigation condition. The fact that the general combining ability (GCA) of genotypes according to productivity, single boll weight, lint yield, lint index traits in normal and low water supply regimes is higher than the specific combining ability (SCA) variance indicates the importance of additive genes in the development of these traits. Suitable parental genotypes and promising hybrids for the improvement of the yield characteristics of cotton in drought conditions were identified too. In this regard, Omad and Ishonch cultivars by their seed cotton yield, single boll weight, lint percentage traits, L-490 line, Omad х Determinant-2 and Ishonch х Determinant-2 hybrids by lint index and 100 seed weight trait can be used in selection-breeding works in the future.