Genetic studies of genotypic responses to water stress in upland cotton (Gossypium hirsutum L.)
By: Sohail Kamaran, Muhammad Imran, Tariq Manzoor Khan, Muhammad Zeeshan Munir, Muhammad Adnan Rashid, Muhammad Atif Muneer
Key Words: Genetic variation, Heritability, Water stress.
Int. J. Agr. Agri. Res. 8(6), 1-9, June 2016.
The present study was carried out to examine the potential in cotton germplasm for breeding water stress tolerant plant material, and understand the genetic basis of different morphological traits related to water stress tolerance. Portioned analysis of variance was employed to obtain good parents for this purposes. The parental genotypes MNH-512, Arizona-6218, CIM-482, MS-39, and NIAB-78 were crossed in complete diallel fashion and F0 seeds of 20 hybrids and five parents were planted in the field in randomized complete block design with three replications during 2010. Simple regression analysis of F1 data revealed that additive-dominance model was quite adequate for all morphological traits. The unit slope of regression lines number of bolls (b = 1.07 ± 9.14), boll weight (b = 0.99 ± 0.11), yield per plant (b = 0.96 ± 0.31), plant height (b = 1.10 ± 0.34), leaf area index (b = 0.82 ± 0.27), and ginning percentage (b = 1.01 ± 0.12) suggested that the epistatic component was absent in the inheritance of all characters studied. The result of various plant characters including seed yield showed drastic effects of water stress as compared with those assessed in non-stressed condition. Leaf area index in the analysis of variance suggested that additive variation was more important for the character. Narrow leaf varieties NIAB-78 and CIM-482 were water stress tolerant while varieties Arizona-6218, MNH-512 and MS-39 were broader leaf showing less resistant to water stress. The information derived from these studies may be used to develop drought tolerant cotton material that could give economic yield in water stressed conditions of cotton belt.