Presence of phytoplasma infections in tomato plants in Mauritius

Phytoplasmas were detected and identified in some tomato cultivation areas in Mauritius. Symptoms most frequently observed were abnormal shoot proliferation, stunting, reduced leaf and fruit size and shortened internodes. In field-grown tomatoes the incidence of abnormalities rarely exceeded 10%, but under hydroponics up to 100% incidence has been recorded. Two different phytoplasmas were identified by PCR/RFLP analyses. Field-grown tomatoes were infected with a phytoplasma belonging to ribosomal subgroup 16SrI-C and the hydroponically-grown tomatoes were infected with a phytoplasma belonging to ribosomal group 16SrV. Further studies need to be done in order to determine their occurrence, incidence, characterization, host range and mode of transmission, so that eventually the most effective method to control phytoplasma diseases will be determined.