Effect of cytokinin on In vitro growth and biomass production of some soil fungi

Effect of different concentrations of cytokinin was studied on growth of four species of soil fungi namely, Aspergillus oryzae, A. terreus Thom, A. niger van Tieghem and Alternaria alternate (Fr.) Keissler. The hormone was applied singly in various concentrations. Increased growth rate and biomass production revealed significant values when treated with dilute solutions of Cytokinin at 15, 30 and 45 mgL^-1. For all test fungi fresh weights and dry weight values dropped significantly when treated with 60 mgL-1 concentration of the hormone solution. The data on fresh and dry biomass revealed that the highest biomass increase was obtained for A. alternata. Fresh biomass of A. alternata showed 39.9% increase when treated with 45 mgL^-1 concentration of hormone solution in comparison to control, whereas an increase of 43.75% was obtained in the case of dry weight. At 60 mgL^-1, a significant fresh biomass suppression of 17.9% and 17.64% was observed for A. niger and A. oryzae, respectively. The highest loss for dry biomass was noticed in A. alternata (18.75%).