A High-Throughput Hydroponic Assay for Rapidly Screening Drought Tolerance in Potato.

Potato (Solanum tuberosum L.) yield is highly sensitive to drought stress, yet robust phenotyping methods for drought tolerance remain scarce. To address this challenge, we present a rapid, high-throughput hydroponic assay designed as an efficient pre-screening tool for evaluating potato cultivars and CRISPR-edited lines. This protocol serves as a foundational screen, enabling researchers to identify the most promising genotypes before committing resources to more extensive soil or field trials. The system uses repurposed pipette tip boxes as low-cost, scalable hydroponic units, making the method highly accessible. Over a five-week period, plantlets are subjected to controlled 24-hr osmotic stress with polyethylene glycol (PEG-6000) and then assessed for resilience based on biomass, photosynthetic measurements, and visual recovery. This resource-efficient assay provides a controlled environment to minimize experimental noise and has been successfully applied to characterize CRISPR-edited potato lines. By providing a reproducible platform for initial evaluation, this protocol accelerates the selection pipeline for developing robust potato varieties for a changing climate. © 2025 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Preparation of stem explants and in vitro rooting Basic Protocol 2: Assembly and maintenance of tip-box hydroponic units Basic Protocol 3: PEG-induced drought treatment and recovery Basic Protocol 4: Post-stress phenotypic, biomass, and photosynthetic analysis.