Abstract:

The aim of this study was to determine the general combining ability (GCA) of the parents and the specific combining ability of their hybrid combinations and to evaluate the hybrid vigor of F1 by investigating the genetic structure of the lines and testers. The study was carried out in randomized complete blocks design with three replications in the trial site of Nazilli Cotton Research Institute in 2015 and 2016 years. 28 F1 hybrids (4 lines and 7 testers) were used as material which developed from line x tester method. Investigated properties except fiber length in the created populations were influenced by non-additive gene effect. The values of heterosis for the seed cotton weight per boll, earliness ratio, ginning percentage, fiber length and micronaire were found positive while seed cotton yield was negative. In the established populations, the investigated traits except fiber length were affected by the non-additive gene effect. Seed cotton weight per boll earliness ratio, ginning percentage, fiber length and micronaire were positive while seed cotton yield was found negative. For seed cotton yield Gloria, TMN 199 and ZN 1018; for earliness ratio TMN 199, GW 2357 and TMN 170; for seed cotton weight per boll GW 2357 and Gloria; for seed index İpek 607; for ginning percentage TMN 199, TMD 139 ZN 1018; for fiber length Gloria, Flash, İpek 607 and UA 48; for fiber fineness İpek 607 and TMD 139; for fiber strength Gloria and UA 48 were found the best parents and also performed the best overall combining abilities for these traits. TMN 199 x İpek 607, TMN 199 x UA 48, Flash x GW 2357, Gloria x İpek 607, Gloria x UA 48 and ST 468 x ADN 712 for seed cotton yield; TMN 199 x TMN 170 for earliness ratio; Flash x GW 2357 and Gloria x İpek 607 for seed cotton weight per boll; TMN 199 x GW 2357 and Gloria x ADN 712 for seed index; Gloria x TMD 139, TMN 199 x TMN 170, Flash x ZN 1018 and ST-468 x TMN 139 for ginning percentage; Flash x ADN 712 and ST-468 x İpek 607 for fiber length; ST-468 x İpek 607 for fiber micronaire; TMN 199 x UA 48, Flash x İpek 607, ST-468 x GW 2357 and ST-468 x UA 48 for fiber strength were indicated the most promising hybrids and had the best overall combining abilities.

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