Word of the Week - Oomycetes

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Earlier this week, I was participating on a Virtual Zoom presentation for Master Gardener Volunteers in Lucas County. This year's interns were treated to a Plant Pathology presentation by OSU's Plant and Pest Diagnostic Clinic's Program Director, Joy Pierzynski, Ph.D. While there were a lot of words that Joy shared with this new group of OSU volunteers, I picked one that I just love to hear. 


This week's word of the week is OOMYCETES (oh-eh-my-ceet).  Merriam-Webster defines oomycetes as subclass of parasitic of saprophytic fungi (class Phycomycetes) that includes water molds, white rusts, and downy mildews. 


Oomycetes are in their own group of organisms. Their sprores can 'swim' through water. Their fruiting structures are called sporangia that can survive in soil for many years. 


While digging deeper, I found an excellent resource that was posted on The American Phytopathological Society (APS) website written by William E. Fry at Cornell University and Niklaus J. Grünwald with USDA-ARS, Introduction to Oomycetes. I addition to the background information that builds a nice foundation, the authors highlighted many examples of oomycetes.


Some notable oomycetes include: 

  • Phytophthora infestans, the potato late blight pathogen

  • Plasmopara viticola, the cause of grapevine downy mildew

  • Phytophthora cinnamomi, the cause of Phytophthora root rot of many plants

  • Phytophthora ramorum, the cause of sudden oak death


If this week's word of the week has you interested in learning more, here is the link to the publication Introduction to Oomycetes mentioned above https://www.apsnet.org/edcenter/disandpath/oomycete/introduction/Pages/IntroOomycetes.aspx