The development and a cytogenetic study of monosomics of Gossypium hirsutum L.

Monosomics of cotton (Gossypium hirsutum L.) were obtained by irradiation o f pollen by gamma-rays and by irradiation of seeds by thermal neutrons. Man y monosomics were derived directly from irradiation, but a number of monoso mics were also recovered in the progeny of plants with translocations and o f desynaptic plants. Only 28 primary monosomics showed normal pairing at me taphase-1 of meiosis. The others formed rare trivalents or additional univa lents. Partial desynapsis was detected in some monosomics. The pollen ferti lity levels of monosomics are presented. New morphological characters were detected among the monosome plants of cotton.