The effect of beta-sitosterol on spore germination and germ-tube elongation of Aspergillus niger and Botryodiplodia theobromae.

The effect of beta-sitosterol on spore germination and prevention of elongation of germ-tube of Aspergillus niger and Botryodiplodia theobromae was studied. The antifungal activity of the compound showed a percentage inhibition, of the fungal spore germination, of about 40% at a concentration of 50 micrograms/ml while inhibition on the elongation of germ-tubes was as high as 65% at the same concentration. The ED50 for inhibition of germ-tube elongation in A. niger was about 31 micrograms/ml. The role of the compound in disease resistance is discussed.