Development of a methodology for the propagation of 'Calcutta 4' (AA) and plantain genotypes from embryogenic cell suspensions and its interface with mutation breeding

Bananas and plantains represent a major staple food for many millions of people in the tropics and subtropics. In Cuba, this crop constitutes a high priority of the national food program because of its capacity of producing fruit all year round, high demand and diversity of use, however, Black Sigatoka disease, caused by the leaf pathogen Mycosphaerella fijiensis, and pests and stress climatic conditions, has resulted in significant yield losses in this culture, which increases the production costs considerably. Somatic embryogenesis combined with mutation induction into in vitro culture mutations has not been studied in depth probably due to the low plant regeneration percentage of different Musa genotypes. Taking into consideration, the previous information following research objects are being developed: to develop a new methodology for developing somatic embryogenesis in different cultivar AAB, and cv. 'Calcutta 4', to develop a methodology for mutation induction with irradiations gamma rays to embryogenic cell suspensions and study anther culture of diploid cultivars. The genetic stability of plants obtained via embryogenesis through embryogenic cell suspensions showed the possibility to use the new methodology for developing somatic embryogenesis in different cultivar. From the results obtained for each cultivar, it is recommended to irradiate cv. 'Calcutta 4' at 50 Gy and cv. 'CEMSA 3/4' at 80 Gy. Irradiations with gamma rays to embryogenic cell suspensions resulted in a shorter stature in regenerated plants. Besides, plants of French plantain type were obtained from cultivar CEMSA 3/4. In Calcutta 4 the irradiation effect caused colour changes in plant pseudo-stems, and also deformed leaves were shown, but did not cause changes in the cultivar susceptibility to Black Sigatoka disease. In anther culture of diploid, callus induced from the state of uninuclate development was higher in relation to the other states studied and the regeneration plants are in progress. (author)