Abstract
1. The present paper deals with the results of the investigations on the influence of azo-pigment congo red, chrysoidin, Bismark brown, and methylorange to Cochliobolus miyabeanus.
2. Congo red and chrysoidin possess the obvious fungistatic effect on the mycelial growth of the fungus showing definite retardation of the lag phase (primary stage) of the mycelial growth, when the fungi were cultivated in the 7.5×10-4∼5×10-4M solution. Congo red is more effective than chrysoidin. Methylorange and Bismark brown, however, have no retarding effect on the mycelial growth.
3. Chrysoidin (basic dye) showed the more marked suppression of the fungus growth in the alkaline side of the nutrient solution. Methylorange (acid dye), however, did not show the distinct effect on the growth of the fungus in the acid side of the solution.
4. Congored seemed to have no effect on the germination of the fungous conidia. In the concentrated solution, however, all germ-tubes swell and change into spore-like vesicles immediately after their germination. No germination of spores took place in distilled water, when they were suspended for one hour in 10-3M solution of chrysoidin.
