Genomics-Based Marker Discovery and Diagnostic Assay Development for Wheat Blast.

Area of Science:

• Plant Pathology
• Molecular Biology
• Genomics

Background:

• Wheat blast is a significant threat to global wheat production, with the pathogen Magnaporthe oryzae Triticum pathotype spreading across South America and Asia.
• The pathogen is morphologically indistinguishable from other Magnaporthe oryzae pathotypes, complicating field identification.
• Wheat blast symptoms mimic Fusarium head blight, hindering accurate disease monitoring.

Purpose of the Study:

• To develop a specific diagnostic tool for the wheat blast pathogen, Magnaporthe oryzae Triticum pathotype.
• To identify unique molecular markers for genotypic characterization of the Triticum pathotype.
• To create a reliable polymerase chain reaction (PCR)-based assay for pathogen detection.

Main Methods:

• Genomics-based approach to identify unique molecular markers for the Triticum pathotype.
• Selection of the MoT3 marker for diagnostic assay development.
• Development and specificity evaluation of a conventional PCR assay using DNA from 284 M. oryzae isolates and Fusarium spp.

Main Results:

• A unique molecular marker, MoT3, was identified for the Triticum pathotype.
• A specific PCR-based diagnostic assay was developed using the MoT3 marker.
• The assay demonstrated high specificity, accurately amplifying from purified DNA and showing no amplification with Fusarium spp. DNA.

Conclusions:

• The MoT3-based PCR assay provides a reliable method for specific detection of the wheat blast pathogen.
• This diagnostic tool can aid in monitoring and managing the spread of wheat blast globally.
• Genotypic characterization is crucial for distinguishing M. oryzae pathotypes affecting wheat.