Genetic variability predicting breeding potential of upland cotton (Gossypium hirsutum L.) for high temperature tolerance

Abstract Background High temperature stress at peak flowering stage of cotton is a major hindrance for crop potential. This study aimed to increase genetic divergence regarding heat tolerance in newly developed cultivars and hybrids. Fifty genotypes 40 F 1 (hybrids) were tested under field conditions following the treatments, viz., high control August October April June sowing, respectively. Results The mean squares revealed significant differences among genotypes, genotype × treatment relative cell injury, chlorophyll contents, canopy temperature, boll retention seed yield per plant. diversity 50 was analyzed through cluster analysis susceptibility index (HSI). tolerant including FH-Noor, NIAB-545, FH-466, FH-Lalazar, FH-458, NIAB-878, IR-NIBGE-8, Weal-AG-Shahkar, sensitive, i.e., CIM-602, Silky-3, FH-326, SLH-12 FH-442 hybridized line tester fashion produce populations. breeding materials’ populations (40 ) higher specific combining ability variances along with dominance variances, decided non-additive type gene action all traits. best general effects most traits displayed by lines, NIAB-878 testers FH-326 Silky-3. Specific better-parent heterosis showed crosses, FH-Lalazar contributing stress. Conclusion Heterosis should be carried out presence studied combiner parents may used crossing program develop yielding cultivars, hybrids tolerance.