TOXICITY OF ETHANOL DURING PROLIFERATION AND ADVENTITIOUS ROOT-FORMATION IN APPLE MICROCUTTINGS IN-VITRO

We have examined the toxicity of ethanol in tissue culture of the appl e rootstock 'Jerk 9'. During proliferation through axillary branching, 0.2 % (v/v) ethanol slightly stimulated proliferation whereas signifi cant inhibition occurred at concentrations of 0.4 % or higher. In adve ntitious root formation, significant inhibition occurred at concentrat ions of 0.1 % or higher. The effect of ethanol was stage-dependent: du ring the induction period (i.e. from 24 to 72 h after the start of the rooting treatment); there was little or no inhibition. During autocla ving, ethanol evaporated to ca. 50 %.