Apple proliferation (AP), pear decline (PD) and European stone fruit yellows (ESFY) are among the most economically important plant diseases that are caused by phytoplasmas. Phylogenetic analyses revealed that the 16S rDNA sequences of strains of each of these pathogens were identical or nearly identical. Differences between the three phytoplasmas ranged from 1.0 to 1.5% of nucleotide positions...

The trivial name 'phytoplasma' has been adopted to collectively name wall-less, non-helical prokaryotes that colonize plant phloem and insects, which were formerly known as mycoplasma-like organisms. Although phytoplasmas have not yet been cultivated in vitro, phylogenetic analyses based on various conserved genes have shown that they represent a distinct, monophyletic clade within the class Mo...

A real-time PCR assay conjugated with the fluorescent SYBR Green I dye has been developed for rapid, sensitive and quantitative detection of ‘Candidatus Phytoplasma prunorum’ in its natural hosts, in stone fruits such as apricot plants and in the insect vector Cacopsylla pruni. The selected primers amplified specifically a fragment 153 bp long from the rplV (rpl22) gene of ‘Ca. P. prunorum’ and...

Apple proliferation (AP) and pear decline (PD) are the most severe diseases in pome fruit growing areas. AP-infected trees show typical symptoms such as witches’ broom, enlarged stipules, tasteless, and dwarf fruits. PD-infected pears show a progressive weakening, reduced terminal growth, smaller fruits, and die within weeks (quick decline) or years (slow decline). The diseases are caused by th...

the witches’ broom disease of lime trees is a destructing disease caused by the bacterium candidatus phytoplasma aurantofolia (1). the disease is prevalent in oman,united arab emirates and iran. to restrict the spread ofthe infected trees, detection of the causative bacteriumis crucial. besides pcr-based methods, antibodies can beapplied for detection of pathogen-infected cells.recently shahrya...

Prunus and Pyrus species affected with phytoplasma diseases, as well as leafhopper species collected from Prunus and Pyrus fields in Ontario, Canada were tested for presence of phytoplasmas. Preliminary results showed that Graminella nigrifrons is a potential vector for phytoplasma groups 16SrI-W (‘Candidatus Phytoplasma asteris’), and 16SrVII-A (‘Candidatus Phytoplasma fraxini’) to a variety o...