Yedidia, I., Ornamental Horticulture Department, ARO the Volcani Center, PO Box 6, Bet-Dagan 50250, Israel
Ophir, R., Ornamental Horticulture Department, ARO the Volcani Center, PO Box 6, Bet-Dagan 50250, Israel
Yishay, M., Ornamental Horticulture Department, ARO the Volcani Center, PO Box 6, Bet-Dagan 50250, Israel
Ion, A., Ornamental Horticulture Department, ARO the Volcani Center, PO Box 6, Bet-Dagan 50250, Israel
Luzzatto, T., Ornamental Horticulture Department, ARO the Volcani Center, PO Box 6, Bet-Dagan 50250, Israel
Golan, A., Ornamental Horticulture Department, ARO the Volcani Center, PO Box 6, Bet-Dagan 50250, Israel
Burdman, S., Department of Plant Pathology and Microbiology, Faculty of Agricultural, Food and Environmental Quality Sciences, PO Box 12, Rehovot 76100, Israel

Pectobacterium carotovorum subsp. carotovorum (Pcc) is a major threat to some monocotyledonous ornamentals production and development. An example of such susceptible crop is the colorful Zantedeschia also known as calla lily. The bacterial pathogen may destroy a whole crop in just a few days. Nevertheless, the association between Pcc isolates and monocots including calla lilies was hardly studied. We have characterized the virulence of several Pcc isolates from different plant sources towards the ornamental monocot plant Zantedeschia aethiopica (calla lily) and a common dicot plant Brassica oleracea (cabbage). In addition genetic analyses were used to characterize Pcc isolates from diverse geographical locations and from plants belonging to four unrelated orders of ornamental monocots and five orders of dicots. Isolates originating from monocots exhibited higher virulence towards calla lily than dicot isolates. In addition, Pcc isolates were differentiated by their AFLP clustering. We suggest that Pcc isolates from monocots display genetic specialization towards the monocot host calla lily independently of their geographical or plant source.