Inoculation Techniques of Crude Extract Toxin Produced by Pyricularia oryzae Cav

Abstract

The mechanical wounding of leaves is necessary for symptom development when inoculated with crude extract toxin (CET) as well as the most suitable method of inoculation for detached leaf and whole plant conditions. The experimental results revealed that the CET could produce disease symptoms even without leaf wounding before inoculation. For detached leaf condition, inoculation by micropipette was found to be efficient and effective. While foliar spray method was the most suitable for whole plant inoculation, symptoms produced by crude extract toxin varied to methods of inoculation. A 30 microlitres drop of CET by micropipette inoculation produced the similar typical blast symptom whereas spray inoculation produced small brown necrosis spots. CET spraying on detached leaves and whole plants gave the same result indicating that CET could be applied for screening toxin resistance on the whole plant condition.