Genetic analysis of yield components and fibre quality characters in upland cotton (Gossypium hirsutum L.)

Generation mean analysis was carried out to estimate the nature and magnitude of gene effects for yield components and fibre quality traits in four crosses of upland cotton (Gossypium hirsutum L). The presence of epistasis was reflected by scaling tests and inadequacy of simple additive-dominance model for most of the characters studied. The results obtained revealed that the nature and magnitude of gene effects differed in different crosses and showed importance of additive as well as non additive gene effects in the inheritance of different characters. In view of the parallel role of additive and non additive gene effects in the inheritance of different characters, selection in the segregating generations should be delayed when dominance gene effects would have diminished or sophisticated selection procedures as recurrent selection and population improvement programmes may be followed. However, additive gene effects may be fixed in the pure lines with respect to some specific traits such as boll weight in cross 1 and 4 while for 2.5 span length in cross 2.