Inheritance of Water Stress Tolerance and Combining Ability in Cotton (Gossypium hirsutum L.)

The water deficiency in all cotton-growing areas has reduced the chances of obtaining high yields in recent years. Therefore, developing cotton that is tolerant to water stress, has a high yield, and has superior fiber quality traits is one of the most crucial breeding objectives. In this study, Ramses, Bomba, Fiona, May-455, Bir-949, and Ozbek-100 cotton varieties with high yield and fiber technological properties were used as the female; Eva, Sahin-2000, Sasha, and Sahra-09 cotton varieties tolerant to water stress were used as the male. These were crossed according to the line × tester mating pattern, and 24 F1 hybrids were obtained. The parents and F1 hybrids were tested under 100% and 25% irrigation. Genotypes performed significantly differently in irrigation conditions. Ginning out-turn and fiber length under both normal and deficit irrigation conditions were controlled by additive genes, whereas seed cotton yield, fiber fineness, and fiber strength were controlled by non-additive genes. Among the parents, Bir-949 had the highest mean values for all traits, whereas Sahra-09 had significant and positive GCA effects. The Bir-949 × Sahra-09 hybrid combination obtained from crossing the best combining parents was the most promising hybrid regarding average performance and SCA effects.