- A semi-selective medium was developed for detection of Pseudomonas syringae
pv. tomato (Pst) from tomato seeds, utilizing qualitative and quantitative antibiogrammes. Growth
tests of the pathogen were carried out with five isolates collected in tomato producing fields of
Brazil. Also, several concentrations of antifungal (chlorotalonil) and halofilic (sodium chloride)
agents were compared within them. The semi-selective medium was developed from a basic medium
Kings B (proteose peptone nº 3, 10g; K2HPO4, 1,5g ; MgSO4.7H2O, 15g; glicerol, 10ml; NaCl,
15g; clorothalonyl, 200g; agar, 15g; destilled water, 1000ml; cefadroxyl, 50g/ml; cephalexin
50g/ml and clindamicin, 100g/ml). This medium presented a repressivity factor of 1,3% and
repressivity index around 30%, high supressivity index, slow cost and sensibility of 3,0-3,6 x
102cfu/g of seed.