Studies on the toxins of Pyricularia spp.-the phytotoxicity of culture filtrates

Abstract

Filtrates from cultures of 5Pyricularia spp. from different graminaceous hosts and, isolates of P. oryzae from rice belonging to 10 races were analysed for phytotoxic components by thin-layer chromatography and bioassay techniques. A number of phytotoxic components including pyriculol was detected. A component which was apparently the reduced form of pyriculol was also detected in some of the toxic eluates of the chromatograms. The components could be distinguished by their characteristic UV absorption spectra. Most of the components appeared to be unsaturated and phenolic in nature. The number and nature of the components varied with the isolate, medium and cultural condition.