Phytoplasmas and Xylella spp. are bacteria that cause many economically important plant diseases worldwide. TaqMan probe-based quantitative real-time polymerase chain reaction (qPCR) assays have been utilized to universally detect phytoplasmas or Xylella fastidiosa. To develop a superior universal qPCR method, we used a dual priming oligonucleotide (DPO) with two annealing sites as a reverse pr...

Scanning electron microscopy (SEM) was applied to detect the phytoplasmas and other phloem inhabiting pathogens associated with some emerging diseases of agricultural crops. The original technique of specimens’ preparation was used to observe the internal structure of phloem tissue. Phytoplasma cells ranging from 400 to 2000 nm were observed in phloem tissue of all analyzed samples of different...

In Korea, Japanese chestnut trees (Castanea crenata Sieb. and Zucc.) showing symptoms indicative of witches' broom disease, including abnormally small leaves and yellowing of young leaves, were examined. Since the symptoms were suggestive of a phytoplasma infection, tissues were assayed for phytoplasmas by PCR analysis using a pair of universal primers that amplify a 1.4-kbp phytoplasma 16S rDN...

Phytoplasmas, biotrophic wall-less prokaryotes, only reside in sieve elements of their host plants. The essentials of the intimate interaction between phytoplasmas and their hosts are poorly understood, which calls for research on potential ultrastructural modifications. We investigated modifications of the sieve-element ultrastructure induced in tomato plants by 'Candidatus Phytoplasma solani,...

Phylogenetic analysis of a 500 bp fragment of the secA gene has been performed on 35 phytoplasma isolates representing 10 of the 16S rDNA groups. The lineages obtained coincide with those delineated by 16S rDNA phylogenetic analysis but much greater genetic variability was evident. In addition, phylogenetic analysis based on part of the 23S rDNA gene combined with T-RFLP (terminal restriction f...

Detection of phytoplasma classified in phylogenetic group 16SrI, ‘Ca. Phytoplasma asteris’, in the plants of interspecific genotypes of Brassica oleracea x Brassica napus and their back-cross toward B. oleracea (IW7.7xB1) is reported in Poland. The presence of phytoplasmas in leaves of plants showing failure of flower bud formation but not in the asymptomatic hybrids was demonstrated by polymer...

Potato purple top (PPT) is an emerging potato disease complex. The etiological agents of PPT are phloem-inhabiting, cell wallless bacteria known as phytoplasmas. Tomato is an alternative host of these phytoplasmas. PPT phytoplasma-infected tomato plants exhibit symptoms including abnormal foliage development and formation of “big buds”. In the present study, twodimensional gel electrophoresis (...

Phytoplasmas are a group mollicute plant pathogens transmitted by insect vectors in the Hemiptera. Although vector species have been identified for many of plant diseases associated with phytoplasmas, little is known about the specificity of vector transmission. Some phytoplasma strains seem to be specifically transmitted, for example phytoplasmas in the Elm yellow group seem to be transmitted ...

Physalis is an herbaceous species native to the Andes region. Currently, it cultivated in various Brazilian states due economic interest of growers for this new fruit. plants grown field showed symptoms shoot proliferation, leaf malformation, and chlorosis. Since these are commonly induced by phytoplasmas, study investigated confirm presence prokaryotes symptomatic plants. After DNA extraction ...

'Candidatus Phytoplasma mali' is a phytopathogenic bacterium of the family Acholeplasmataceae assigned to the class Mollicutes. This causative agent of the apple proliferation colonizes in Malus domestica the sieve tubes of the plant phloem resulting in a range of symptoms such as witches'--broom formation, reduced vigor and affecting size and quality of the crop. The disease is responsible for...