Pseudomonas marginalis associated with soft rot of Zantedeschia spp.

For the first time in the Czech Republic, bacteria identified as Pseudomonas marginalis, Pectobacterium carotovorum subsp. carotovorum and Pseudomonas putida were isolated from tubers of Zantedeschia spp. with symptoms of tuber soft rot. The symptoms occurred on mother tubers as well as on new daughter tubers of different calla lily hybrids with yellow spathe, calla lily cv. Mango with bright orange spathe and Zantedeschia rehmanii with pink spathe. The percentage of diseased plants of the total plants in the plot was around 10%. When inoculated into potato tuber slices, strains of P. marginalis and P. c. subsp. carotovorum produced soft rot. Pectolytic activity of P. marginalis strains was less intensive than that of the P. c. subsp. carotovorum strain. The results confirm that bacterial soft rot of Zantedeschia spp. may have several causes.