Association of mycoplasma‐like organisms with tomato big bud disease in Greece

Abstract

The big bud disease of tomato is described in Greece for the first time. Its identity and aetiology were ascertained by electron microscopy, fluorescence and bright‐field microscopy, transmission tests and antibiotic treatments. Pleomorphic mycoplasma‐like organisms (MLOs) were detected in the sieve tubes of infected leaf tissues by thin‐section electron microscopy and also by fluorescence and bright‐field microscopy after staining with the DNA‐binding fluorescent stain Hoechst 33258, and with toluidine blue. Infected tomato plants showed remission of symptoms when treated with tetracycline‐HCl, but not with benzylpenicillin, while healthy plants developed big bud symptoms when graft inoculated with diseased tomato shoots. The occurrence of natural spread of big bud disease in Greece indicates that one or more vector species are present in the country.