IDENTIFICATION OF POTENTIAL PLANT MATERIAL AND GENETIC ANALYSIS FOR DROUGHT TOLERANCE IN UPLAND COTTON BASED ON PHYSIOLOGICAL INDICATORS

Climate change has drastically reduced the water availability which negatively impacted the cotton production. Cotton crop is sensitive to drought as it may affect its growth and development. For this purpose, hydroponic culture was used to evaluate 37 cotton genotypes under both control and drought -imposed (PEG -6000) conditions to identify drought tolerant (MNH-886 and MNH-988) and sensitive genotypes (FH-114 and FH-Kehkshan) based on reliable physiological indicators i.e., relative water content, excised leaf water loss and cell membrane stability using k -means cluster analysis and biplot analysis. These genotypes were hybridized to develop F1 populations (MNH-886 x FH-114 and MNH-988 x FH-Kehkshan) and segregating populations (F2, BC1 and BC2). Both cross combinations along with their generations were planted in field area using Randomized Complete Block Design under normal and drought conditions. Results reflected complex quantitative type of inheritance. Larger influence of non -additive effects along with epistatic interactions of aforementioned traits and seed cotton yield showed significant importance for suggesting delayed selection in segregating populations. Additionally, presence of low to moderate narrow sense heritability and undesirable association of physiological indicators with seed cotton yield suggested the same i.e., selection in later segregating generations to improve drought tolerance in further breeding programs.