Stimulation of the formation of fruiting bodies of the fungusLentinus tigrinus (Bull.) Fr. by growth regulators

Growth regulators, indole-3-acetic acid (IAA), gibberellic acid (GA₃), and kinetin (KIN), were used in different concentrations to stimulate the initiation and further development of the fruiting bodies of the fungusLentinus tigrinus. Vegetative mycelium of the fungus was cultivated on cellulose cylinders soaked with a synthetic nutrient solution or with a 3% malt extract. When the mycelium covered the surface of the cylinders, further cultivation was carried out in graduated concentrations of the growth regulators mentioned above. The number of developed fruiting bodies showed that the optimum IAA and GA₃ concentrations were in both media 300 p.p.m. The optimum concentration of kinetin was 400 p.p.m. The individual growth regulators influenced characteristically also the shape of the fruiting bodies and changed in them the natural level of endogenous growth regulators. The addition of IAA into the medium raised the level of endogenous auxins in the cap. The presence of gibberellic acid and of kinetic in the medium resulted in an increase in the level of these regulators in the fruiting bodies.