EFFECT OF GROWTH REGULATORS ON INDIRECT ORGANOGENESIS OF Acacia mearnsii TISSUES CULTURED IN VITRO1

ABSTRACT- In order to achieve adventitious shoot regeneration from young tissues of Acacia mearnsii, several combinations of growth regulators were tested. Kinetin (KIN) and α-naphthaleneacetic acid (NAA) or thidiazuron (TDZ) and NAA were added to basic medium composed of 1/2 strength MS salts, MS vitamins and 2 % sucrose. Sections of hypocotyls and cotyledons of young seedlings were cultivated on these media. Calli developed on different media and, after two to three months, they regenerated buds and roots. The best results for bud regeneration were obtained with cotyledons, when cultured in the presence of 2.33 to 9.30 µM KIN or 1.82 µM TDZ and 2.69 µM NAA