Studies on Gene Effects in IntervarietalCrosses of Hirsutum Cotton

Basic sets of six generations of two varietal crosses of cotton were studied to estimate nature and magnitude of gene effects operative in the inheritance of yield components and fibres quality traits. Scaling tests as well as joint scaling test detected the presence of epistasis for seed cotton yield, bolls per plant, boll weight and 2.5% span length in cross LH900 x Senegal and for boll weight, ginning outturn and 2.5% span length in cross LH900 x LRA 5166. Additive-dominance model was sufficient to explain variation in generation means for the remaining traits. Inheritance pattern of various traits differed in the two crosses and additive as well as non-additive gene effects were found to be important. Keeping in view the importance of both additive and non-additive gene effects, it was suggested that sophisticated selection procedures as recurrent selection and population improvement might be followed for simultaneous improvement of yield and fibre characters.