An Accurate, Affordable, and Precise Resazurin-Based Digital Imaging Colorimetric Assay for the Assessment of Fungicide Sensitivity Status of Fungal Populations

This study aimed at the development and validation of an accurate, more affordable, precise digital imaging resazurin-based fungicide sensitivity colorimetric assay (COL-assay) for fungal plant pathogens from genera Mycosphaerella Pyricularia. proposed was based on estimates resazurin reduction, which used as a metabolic indicator respiration activity microplate cultures. As model systems, we yellow black Sigatoka [Mycosphaerella musicola (Mm) M. fijiensis (Mf), respectively] wheat blast pathogen, Pyricularia oryzae Triticum lineage (PoTl), were previously characterized QoI, DMI, SDHI sensitivity. We then compared classical spectrophotometry detection (SPEC-assay) with COL-assay analyses images microplates’ cultures captured mobile phone cameras handmade trans-illuminator built poorly equipped labs. Qualitatively, in terms accuracy, there full correspondence between SPEC-assay according to EC50 or relative growth classes SDHI, DMI fungicides both pathogens. also observed strong very correlation coefficient values QoI azoxystrobin, fluxapyroxad, tebuconazole. Our conclusion that had similar accuracy (i.e., resulted fungicide-sensitivity categories resistant sensitive isolates) high precision. By openly sharing here COL-assay’s methodology, blueprints trans-illuminator, foresee its adoption by labs throughout country affordable venue monitoring resistance status populations important such fijiensis, musicola, P. Oryza lineages.