A High-Throughput Microtiter-Based Fungicide Sensitivity Assay for Oomycetes Using Z'-Factor Statistic

Area of Science:

• Plant Pathology
• Mycology
• Agricultural Science

Background:

• Assessing oomycete fungicide sensitivity is crucial but current methods are slow and labor-intensive.
• Microtiter-based assays offer higher throughput but require robust quality control for reproducibility.
• Developing efficient and reliable methods for assay quality detection is essential for accurate fungicide phenotyping.

Purpose of the Study:

• To develop and validate a robust, high-throughput fungicide phenotyping assay for oomycetes.
• To implement quality control measures, including the Z' factor and growth curves, for assay reliability.
• To compare the accuracy and precision of the new assay against the established amended medium (gold standard) method.

Main Methods:

• Spectrophotometric quantification of oomycete mycelial growth in liquid culture.
• Utilized Z' factor for quality control, ensuring sufficient growth in control conditions.
• Employed growth curves to confirm active growth during EC50 estimation.

Main Results:

• The high-throughput assay demonstrated accuracy comparable to the gold standard method.
• Concordance correlation indicated high accuracy, though precision may be slightly lower than the amended medium assay.
• Successfully tested the sensitivity of 216 oomycete isolates to mefenoxam and ethaboxam.

Conclusions:

• The developed assay enables efficient, high-throughput fungicide phenotyping of oomycetes.
• This method facilitates fungicide sensitivity assessment at population and community levels.
• The assay's quality control mechanisms ensure reliable data for fungicide resistance monitoring.