So 3.1 Pseudomonas syringae pv tomato – tomato2018-04-16T10:42:19-05:00

National Seed Health System

So 3.1  Pseudomonas syringae pv tomato – tomato

DATE: 2001
PATHOGEN: Pseudomonas syringae pv. tomato
HOST: tomato (Lycopersicon esculentum)
COMMON NAME: bacterial speck 
METHOD: So 3.1 CDFA Agar Plating Method (California Department of Food and Agriculture)
SAMPLE: : 30,000 seeds


1. 3 subsamples of 10,000 seeds are measured and placed into a stomacher bag.

2. Each subsample is suspended in 150ml wash buffer and incubated overnight at 4°C.

3. Samples are shaken for 30 min. at room temperature, then (optional) stomached for 30 minutes.

4. A ten-fold dilution series is made and plated onto KBC and KB media.

5. Antagonist checks are made for each subsample.

6. Media checks for each media type used are also made.

7. Plates are incubated for 3-6 days at 25°C.

8. Suspect cultures are subcultured onto KB agar plates and tested with biochemical and pathogenicity tests.