Simple method for determining benomyl tolerance of Venturia nashicola

Abstract

A simple method to detect the tolerant strain of Venturia nashicola (causal fungus of Japanese pear scab) to benomyl was developed. Conidiospores on the diseased leaves were seeded directly on potato sucrose agar media containing given concentrations of benomyl. After incubation for 48 or 72hr at 15C, minimum inhibitory concentration (MIC) of benomyl was determined on the basis of septum formation in germ tubes. By this method, the tolerance and its degree could be determined much easier and faster than the conventional hyphal growth method with the same accuracy, This method was applicable to ascospores as well as conidiospores. The method was named “Germ-tube Septum Method”.