Direct bioautography on thin-layer chromatograms as a method for detecting fungitoxic substances.

A simple bioautographic techniqud according to WELTZIEN', and modified by DEISHUI JZEN~ for detection of fungitoxic substances has been in use for many years in this laborattiry. Chromatograms on Whatman No. 3MM paper are develpped with propanol-water (85: 15) and after drying are sprayed with a conidial suspension of Glomerella cingzclata. After incubation, clearly visible inhibition zones indicate the preserice of. fungitoxic compounds. Chromatography thus permits not only the detection sf fungitoxic substances per se, but also makes the study of the conversion reactions and of decomposition of such compounds possible.