Identification and Biological Properties of the Pathogen of Soft Rot of Tomatoes in the Greenhouse

Recently, in the greenhouses of Ukraine, a sharp increase in the infestation of tomato plants with soft (wet) rot has been registered.

To identify the pathogen of the soft rot, study its biological properties and develop practical recommendations for plant protection measures.

The work was performed using classical microbiological and biochemical research methods. The API 20E (Bio Merieux) test system was used to study the physiological and biochemical properties of the bacteria. The study of bacterial fatty acids was carried out by mass-spectrometry.

Using a bacteriological analysis of tomato plants selected in greenhouses of the Kyiv region, for the first time, virulent strains from this crop were identified and assigned, according to their physiological, biochemical, morphological and cultural characteristics, to the Pectobacterium carotovorum species. The fatty acid profile of the total cell lipids of the isolated strains was distinguished by the presence of 1,13‒1,17%, of 3-hydroxytetradecanoic acid, which is typical for P. carotovorum subsp. carotovorum. It was found that the isolated strains were sensitive to oxychloride and copper hydroxide-based fungicides with 10,5 to 17,5 mm growth inhibition zones.

The causative agent of soft (wet) rot of tomatoes in greenhouses is P. carotovorum subsp. сarotovorum. Fungicides with oxychloride and copper hydroxide are recommended as the active agents to protect tomato plants from the pathogen.