Preparation of Phytophthora zoospore suspensions

This protocol describes the preparation of motile zoospore suspensions from cultures of the plant pathogen Phytophthora capsici. P. capsici is pathogenic toward peppers, cucumbers, and cucurbits. Zoospores are the motile dispersal stage of these oomycetes and are used in multiple demonstrations including chemotaxis assays, root infection experiments, microfluidic soil‑pore models, and microscopy demonstrations. The complete process typically requires 30–60 minutes once actively growing cultures are available. An optional high-yield pre‑sporulation workflow is included to enable rapid zoospore release during teaching laboratories.