Molecular Characterization of Plant Pathogens

Benzimidazole compounds are widely used as fungicides and antihelmintics in agriculture. They have a unique site specific mode of action; point mutation in the -tubulin gene has been shown to confer the resistance to the benzimidazole fungicide benomyl. However resistance to benzimidazoles may also be due to alteration in membrane permeability. A simple technique has been developed in my research to evaluate the resistance of various plant pathogens to benzimidazole compounds in the field. With this method, the level of resistance can be evaluated as well as the mechanism of resistance can be detected. These findings may suggest alternate chemical approaches to breaking the resistance. The objective of the work was to detect the level of benzimidazole resistance in rice the using Allele Specific Oligonucleotides analysis. The appropriate DNA sequence of two 22 mer oligonucleotides was amplified using PCR techniques, which were identical bete-tubulin gene in sequence to codon 359-365 of Venturia inaequalis, were used as primers.