Characterization of Phytomonas isolated from fruits by electrophoretic isoenzymes and kinetoplast-DNA analysis

Two flagellates of the family, Trypanosomatidae were isolated from the fruits of #Lycopersicon esculentum# (tomato) and #Amona cherimolia# (cherimoya) in the southeastern region of Spain. The isolates were characterized by isoenzyme analysis using nine different isoenzymes and by analysis of kinetoplast DNA (kDNA) restriction fragment length polymorphism using four different restriction endonucleases. Most of the isoenzymes were unable to distinguish between the two fruit isolates, while they were all able to distinguish these two from four other #Phytomonas# isolates, three of which were from laticiferous plants, i.e. #Euphorbia characias#, #E. hirta# and #E. hyssopifolia#, and was a phloem-restricted isolate associated with Hartrot disease. Only the enzyme superoxide dismutase was able to differentiate between the two fruit isolates. Electrophoretic and restriction endonuclease analysis of kDNA minicircles, using four restriction enzymes, showed similar if not identical restriction cleavage patterns of the minicircles of the two isolates from fruits, while the patterns were different for the other isolates. These results confirm the hypothesis that the two isolates from fruits constitute a group of trypanosoniatids that are the same or closely related and that this group can parasitize more than one host plant.