Estimating gene action and combining ability for yield and fiber quality in cotton (Gossypium hirsutum L.)

Genetic evaluation of segregating populations is one of the primary activities of cotton breeders. Seven cotton genotypes were crossed in a line ? tester mating design. The population of 12 F1, 12 F2 and their parents were tested in Randomized Complete Block Design with three replications at the Nazilli Cotton Research Institute of T?rkiye during the 2014/2015 cotton-growing season. The genetic variability was significant for all characters studied. ?2GCA/?2SCA indicated non-additive gene action in controlling seed cotton yield (F2), ginning out-turn (F1) and fiber quality traits for both generations. The highly favourable GCA effects for seed cotton yield and fiber strength were recorded in the Carmen cultivar. Carmen ? Carisma hybrid exhibited high mean performance and SCA effects for seed cotton yield and fiber strength, while the performance of Gloria ? ST-468 was superior in terms of ginning out-turn. We concluded that individual plants with desired traits should be selected in later generations due to the preponderance of non-additive gene actions.