Determination of genetic structure of some agricultural and technological characteristics of double cross, inter-specific (Gossypium hirsutum L. x Gossypium barbadense L.) and intra-specific (Gossypium hirsutum L. x Gossypium hirsutum L.) of f1 hybrids in cotton

This study has been carried out in 2008, 2009 and 2010 in the trial area of the SAARI of the Ministry of Agriculture and Rural Affairs. The purpose of the study is to determine the genetic structure of investigated properties in the population which created from 45 double cross F1 generation, using the double cross breeding method; to determine the heterotic effects on the traits, to determine the suitable parents according to the examined traits and cross combinations which compiling a lot of traits for six genotypes of cotton varieties of 4 G. hirsutum L. and 1 G. barbadense L. Another purpose of this study is to help the trait breeding researches.According to the study, with respect to the number of bolls per plant, seed cotton weight per boll, fiber length and fiber fineness in the formed population, it can be seen that additive and epistatic gene effects (additivexadditive, additivexdominant); with respect to the first picking percentage and spinning consistency, the additive and epistatic gene effects (additivexadditive, additivexadditivexadditive, dominantxdominant); in terms of the lint percentage and lint yield the additive, dominant and epistatic gene effects (dominantxdominant and additivexadditivexadditive); with respect to seed cotton yield, the additive, dominant and epistatic gene effects (additivexdominant) were effective. In the created population of double cross, with respect to the bolls per plant, seed cotton yield, fiber yield, fiber length, fiber fineness, short fiber index and spinning consistency index, positive heterotic effect was observed. In terms of the seed cotton weight per boll, lint percentage, first picking percentage and fiber strength, the presence of negative heterotic effect was observed in the created population of double cross.This study was concluded that the genotypes of the STV-468 and Paum 15 in terms of the traits of the number of bolls per plant and seed cotton yield, genotypes of the Nazilli-84S, Fantom, Delcerro and Giza-75 in terms of the seed cotton weight per boll; genotypes of the STV-468 and Nazilli-84S in terms of lint percentage, genotypes of the Paum 15, STV 468 and Nazilli 84S in terms of the lint yield; genotypes of the Paum-15, and Fantom in terms of the first picking yield; genotypes of the Delcerro and Giza-75 in terms of the fiber length, fiber fineness, short fiber index and spinning consistency index; and genotypes of the Paum-15, STV-468, Delcerro and Giza-75 in terms of the fiber strength might be used as a parent in the cotton breeding programs.