Some features of media for good sporulation of Phytophthora sp. were described in http://www.apsnet.org/publications/phytopathology/backissues/Documents/1972Articles/Phyto62n09_993.pdf. But oatsmeal agar is usually good for it. (http://books.google.ru/books?id=vSTvzcR6MgcC&pg=PA357&lpg=PA357&dq=Phytophthora+oats+agar&source=bl&ots=kYScjkUhQL&sig=GRpOTkue6JOXCPw4B4ZqwHKwIA0&hl=en&sa=X&ei=Xl74UouMOYLa4wTcjYAY&redir_esc=y#v=onepage&q=Phytophthora%20oats%20agar&f=false)

Take the culture and use ice water you will get zoospores. Use hemocytometer for quantification

So I add ice water to the culture?

Thanks for the feedback, it is really useful.

Thanks, I have been growing in V8.

Thanks, for the feedback. I am working on some of the protocols, and hopefully one of them works.

For P. capsici/Psojae, you can use cold 4C water into your V8 amended highly sporulating plate(s), I do not usually chop the agar. I use a glass rod to rub the sporangia after incubation with water. Filter our the sporangia with a kimpwipe. If you do not see much zoospores, you would have to work out your sporulating conditions. Good luck

I also suggest you see: Erwin & Ribeiro (1996). Phytophthora Diseases Worldwide. APS Press. pp 84-95

Good luck

G'day, check out Irwin 1976 Austalian J Botany 24: 447-451 & Harris 1986 Brit Mycol Soc 86: 482-486. Good luck and have fun, cheers Kevin

Thanks Kevin, I looked it up and got the recipe to make the salt solution to induce sporangia and zoospore release.

Hi Shima, I hope you already have done zoospores release, my experience with P infestans was really suscesfull once we put them on cold water 10°C, but with other species like P parasitica for pineapple or P capsici on pepper did not worked too cold, maybe 15°C would be better, but for sure, media has to be full of water must of time.

Hello Jose,

I have tried to keep at 4°C and not much success is achieved so far. I will try to do at 15 °C. Thanks for taking time to respond.

Sometimes it may help if you rinse the culture with sterile distilled water just before you transfer to the freg, You may also need to vary the chilling period (15-20 min) as well. After chilling, the culture is then kept at room temp for a few minutes. Then one may start examining the culture at 5-min interval until a peak of zoospores release is reached. Good luck

Got a better result with modified condition of temperature n washing before subjecting lower temperature.

You seem to have got a good yield of zoospores! Good luck.

Thanks Mohammed, I was really thrilled to have the results.

Hi, how did you check for the zoospore release? did you just check it using compound microscope?

Could you share your protocol with us? Would this also work for Pythium species? Cheers!