Invasive Species Compendium

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Abstract

Detection and quantification of Pseudomonas syringae pv. lachrymans in cucumber seeds lots.

Abstract

Cucumber seeds were tested for P. syringae pv. lachrymans infection by direct planting. Percentage infection transmission varied from 1 to 2.5%. The Kado and Heskett's 523 selective medium was modified for P. syringae pv. lachrymans by addition of 200 µg/ml of bacitracin, captan, lincomycin and rose bengal. Seeds were placed onto the surface of the selective media, and colonies were counted and tested for pathogenicity. The method allowed detection of bacteria in 1 out of 5 seed lots. For quantification, 500 seeds were submitted to extraction in PBS containing the antimicrobial compounds. Seed extracts were diluted for plate counting. Typical, single colonies were tested for pathogenicity. The method allowed detection of P. syringae pv. lachrymans in all the seed lots. UFC values/g of seed varied between 1.5×107 to 2.5×105.