A method to evaluate percentage of cucurbit seeds infested with Acidovorax avenae subsp. citrulli, pathogen of bacterial fruit blotch

We developed a method to detect Acidovorax avenae subsp. citrulli from cucurbit seeds that is more sensitive than conventional growing-out methods. Seeds were cultivated in test tubes for 2 weeks, and the bacteria grew semi-selectively on the seeds and seedlings. The plants were then vigorously shaken in water to suspend bacterial cells, and the suspension was spread on a selective medium for identifying the bacterium by colony appearance. The method is suitable for research purposes to evaluate the percentage of seeds infested with the bacteria, but not to detect bacterial contamination in commercial lots with thousands of seeds.