In vitro response of Actinidia deliciosa explants to different BA incubation periods

Actinidia deliciosa apical shoots were cultured in MS liquid medium with ce llulose plugs as support for the explants. Different BA (4.4 muM) incubatio n periods were tested in order to improve the effectiveness of the micropro pagation system by reducing the cytokinin incubation period. At the end of 3 successive subcultures, the explants were analysed and a number of parame ters (number, weight and length of shoots, presence and weight of callus, m ultiplication index, etc.) were measured. Different BA incubation periods h ave a long-term effect since the best results at the end of multiplication stage were not followed by better growth at the end of the acclimatised per iod studied. The highest quality plants were those obtained from culturing in the presence of BA for 1 day. Our results show that BA not only has an i mportant effect on the different phases of micropropagation, but will also regulate the future development of the regenerants.