Abstract: The present study was carried out at Agriculture Research Institute (ARI) Tando Jam during 2016. The experimental material consisted of six lines viz., CRIS-134, Sindh-1, Sadori, Malmal, IR-901 and three testers; Bt-3701, Bt-121 and CIM-534.The crosses were made in line × tester mating design. F1 hybrids along with parents were sown in Randomized Complete Block Design with four replications in 2016. Seven yield and early maturing traits was recorded like, days to 1st flowering, days to 75% boll opening, plant height(cm), sympodial branches plant-1, bolls plant-1, seed cotton yield-1(g) and lint (%) for estimating of combining ability. The analysis of variance showed that genotypes, crosses, parents, parent vs crosses, lines, testers and line × tester were significant which demonstrated that genetic difference were present in genotypes for various yield and early maturing parameters. Among the lines, Sindh-1, CRIS-134 and testers, Bt-121 and Bt-3701 were best combiners and F1 hybrids like CRIS-134 × Bt-3701, Malmal × Bt-3701, CRIS-134 × Bt-121 were best combiners for all characters.
Keywords: Lines, testers, line × tester, cotton genotypes, phenological and yield traits.