Irradiation of F 1 and F 2 seeds from the interspecific cross Gossypium hirsutum L x G. barbadense L revealed greater possibilities for its efficient use in genetic and breeding investigations. Combined experimental mutagenesis with distant hybridization of G. hirsutum x G. sturtii F. Mill proved exceptionally efficient also for accelerating the breeding process and for development of valuable forms for breeding. Irradiation of F 1 G. hirsutum x G. sturtii seeds followed by colchicine treatment of F 1 plants (2n=39) in the phase of cotyledons resulted in the development of mutant-hybrid forms, which resemble the cultivated species G. hirsutum and possess a number of valuable characters from the wild growing species. This method may prove very important for use in distant hybridization aiming to use the genetic potential of wild growing species.