In vitro germination of Austropuccinia psidii urediniospores 

Harvest fresh spores from heavily infected leaves by shaking into a paper bag.

Move fresh spores to a glass petri dish with no lid. Transfer petri dish to a desiccator with silica gel beads for 24 - 48 hours to dry the spores.

Sieve spores to remove any plant matter or dirt.

Aliquot spores into Nunc CryoTubes or similar for short or long term storage.

Create 2% water agar plates.

In a 15 mL centrifuge tube, make up inocula to a concentration of approximately 1 mg/mL in sterile distilled water (SDW) with 5ul/mL Tween 20 (0.05%). Mix thoroughly by gently inverting the tube several times.

Rehydrate spores in inocula for 30 minutes prior to use.

Pipette 2 uL aliquots of inocula onto agar plate, covering the entire plate with distinct 2 uL droplets and seal the plates with parafilm.

Germinate in incubator for a minimum of 8 hours in the dark at 18°C and 75% relative humidity.

For each aliquot, count the number of germinated spores under a dissecting microscope. A germinated spore is considered to be a spore with a germination tube at least double the length of the urediniospore.