Hi: make water culture for a 5day culture by taken 5-6 plugs and keep it in petridish to grow for 48h in 25C, after that keep it in 4C for 24h , take it in room temperature for 10 min and check it under microscope you can see a lot of zoospore.

for the oospore you can grow the fungus on the same host that you isolate the fungal from, so you can make medium from  strawberry , you should get a alot of oospore.

Dear Oady Matny,

Thank you. Do you have any reference protocol for Zoospore and oospores production in Phytophthora cactorum?

regards,

Tofazzal

Dear Colleague,

unfortunately I cannot answer your question. I will forward it to my co-worker if he knows.

Best regards and best wishes

Gerhard Artmann

If you can successfully induce sporangia formation than transfer the plug to a petri dish and ice cold water, place the petri dish in dark. Wait for 30 minutes, it should release zoospore. I have used this method to induce zoospore formation in Phytophthora nicotianae.

Oospores can be readily produced by growing Phytophthora cactorum on 10 or 20% clarified Cambell's V-8 juice agar medium. To induce sporangia formation and zoospore release, small agar plugs should be cut from the edge of a young growing colony and placed in sterile distilled water for 24 hours. After incubating them in the refrigerator at about 5C for 30 minutes, the sporangia should release zoospores when they are brought back to the room temperature.

Thank you for sharing your experiences. However, it would be nice if could give us a reference. Phytophthora nicotianae and P. capsici produce abundant zoospores but we have no experience in P. cactorum. Anyway, we shall try.