Spore production for Phytophthora infestans
Take agar cubes / rains from glycerol stock and place 3 - 4 pieces on agar plates .
When using another plate , cut small cubes ( approx 0.5x0.5 cm ) and place 3 - 4 upside down on the agar plate For longer term cultivation use RyeA agar .
For sporulation use RyeB agar .
Grow plates for about 7 days in the dark , until the plate is fully covered Optimum temperature is about 18 - 20°C .
Move plates to at 16 / 8 light / dark cycles for about 2 - 3 days to induce sporulation .
Harvest sporangia by adding several ml ice cold water to the plates and scraping of the sporangia with a pipette tip .
Aspirate all liquid and store in fridge for 3 - 6 hours to induce hatching of the spores .
Pipette off the upper layers ( spores swim up , debris sink ) and check spore density under microsope
