Volume 62 (1996) Issue 2 Pages 114-118
This study was undertaken to investigate the effects of two toxins and a derivative of one toxin produced by rice blast fungus, Pyricularia oryzae (Magnaporthe grisea), on infection to rice plants. The inner epidermal tissue of a detached rice leaf sheath was pre-treated with three compounds and an incompatible race of this fungus was challenge-inoculated. All compounds used in this study, tenuazonic acid, pyriculol and dihydro derivative of pyriculol (dihydropyriculol) induced susceptibility to pre-treated tissues on the infection of this fungus at concentrations greater than 20μg/ml. The most effective toxin was pyriculol, and tenuazonic acid was followed. Only dihydropyriculol was detected in the germination fluid of the conidia of this fungus with HPLC.