Evaluation of agronomic traits of cotton RIL population and its parental genotypes in water deficiency environment

In recent years, global climate change has led to rising temperatures and droughts, which have had a negative impact on agricultural crops. Therefore, the development of new varieties of agricultural crops, including cotton, with increased resistance to abiotic stress and improved productivity remains extremely relevant using modern breeding and molecular genetic programs. In this context, it is crucial to select the initial breeding genotypes with high resistance to water stress and productivity. In this study, 100 recombinant inbred lines (RILs) of cotton (Gossypium hirsitum L.) from the F11 population (Namangan-77 × Zangi-ota), developed by crossing the recipient cotton variety Namangan-77 with the donor variety Zangi-ota, were grown under two different conditions (water stress and optimal). Their agronomic parameters, such as seed cotton weight per boll, 1000-seed weight, fiber staple length and fiber yield, were studied. As a result of the research, it was established that 30 families of the RIL population under conditions of water deficiency showed improved indicators compared to the recipient variety Namangan-77: the seed cotton weight per boll increased by 22 %, the weight of 1000 seeds by 33 %, the fiber staple length by 4.2 % and the fiber yield by 4.4 %. Promising breeding lines from these 30 families, possessing breeding potential, were presented to the State Variety Testing Center as new drought-tolerant candidate varieties. In addition, these families, which showed high agronomic performance under drought conditions, were recommended as donors for future breeding programs and molecular genetic studies.