196,040 research outputs found

    A real-time PCR quantitative detection assay for <i>Pseudomonas savastanoi </i>pv. <i>nerii </i>in <i>Nerium oleander</i>

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    A real-time PCR assay based on TaqMan chemistry was developed for the detection of Pseudomonas savastanoi pathovars that cause bacterial knot disease on different plant species. Primers and probe sequences were based on the iaaL gene coding for (indole-3-acetyl)-L-lysine synthetase and previously used in conventional PCR tests. Assay specificity was tested with an extended range of strains of P. savastanoi from eight hosts, with 13 other Pseudomonas spp., and with other microorganisms naturally occurring on or in oleander plants. A pure culture cell suspension was quantifi ed over a seven log concentration range (108 to 102 cfu ml-1 ). Different protocols were developed for the detection and quantifi cation of P. savastanoi pv. nerii from symptomatic and asymptomatic oleander plants. A 24-h bacterial enrichment step either on PVF-1 or OKA-M broth improved the sensitivity of the assay, making it suitable to screen planting material for latent infections

    L'esaltazione della Dea: un breve approccio al Dev&#299;-M&#257;h&#257;tmya

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    Introduzione al ms. Tessitori e al Dev&#299;-M&#257;h&#257;tmya

    Le malformazioni delle piante nell’iconografia: percorso storico-documentario

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    Plant malformations in iconography: historical-documentary journey -.The present contribution traces the progress of the iconography of plant anatomical anomalies. The cases illustrated in the most important works from the second half of the 17th to the 19th century are here reported

    Characterization of p20 and p23 genes in Corsican isolates of Citrus tristeza virus.

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    Tristeza disease, caused by the Citrus tristeza virus (CTV), is the most important viral disease for almost all the citrus species. Main syndromes are quick decline, stem pitting, vein clearing and seedlings yellows but expression and intensity of symptomatology depends on the interactions of the factors involved in the pathosystem such as host-strain-rootstock-climate-vector. Several isolates of CTV have been studied all over the world. Two Corsican isolates have been previously characterized, the K strain from Marumi kumquat, known to be symptomless on Mexican lime, and the CaL -1 from calamondin inducing stem pitting, but no sequences of p20 gene are published or available in GenBank. Two additional CTV strains were recently found in Corsica. The isolates LA5 and CO3 were detected in two different orchards of 40 year old Clementine on sour orange trees that didn't show any specific symptoms ascribable to tristeza. Results of the molecular characterization of these isolates are reported. CTV presence was ascertained in young shoots collected in field by RT-PCR using specific primers for the gene p20. The amplicons obtained were analyzed by cloning and sequencing. Sequences analysis pointed out high similarity between the two isolates (98%). Multiple alignment analysis with all the p20 CTV gene sequences deposited in GenBank evidenced the identity of the virus detected in the two orchards. Respect to the already described mild, severe and atypical groups of CTV isolates, phylogenetic analysis revealed a new cluster including both LA5 and CO3

    Virescence of tenweeks stock associated to phytoplasma infection in Sicily

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    In April 2007, a severe disease occurred in Sicily (Italy) in a glasshouse cultivation of tenweeks stock belonging to the cultivar White-Beach. Plants were stunted and rosetted, and the flowers were of small size and characterized by virescence symptoms. Phytoplasma presence and identity was detected by applying PCR/RFLP techniques and sequencing of 16S ribosomal gene. Phytoplasmas were identified as belonging to ribosomal subgroup 16SrII-A, never reported before in Italy and showed 99% of homology with 'Candidatus Phytoplasma aurantifolia' and related phytoplasmas. This is the first report of a phytoplasma disease of tenweeks stock. Considering that this Brassicaceae ornamental species is widely grown in Italy, it could play an important role in spreading these phytoplasmas, new for Italy

    Virescence of tenweeks stock associated to phytoplasma infection in Sicily

    No full text
    In April 2007, a severe disease occurred in Sicily (Italy) in a glasshouse cultivation of tenweeks stock belonging to the cultivar White-Beach. Plants were stunted and rosetted, and the flowers were of small size and characterized by virescence symptoms. Phytoplasma presence and identity was detected by applying PCR/RFLP techniques and sequencing of 16S ribosomal gene. Phytoplasmas were identified as belonging to ribosomal subgroup 16SrII-A, never reported before in Italy and showed 99% of homology with ‘Candidatus Phytoplasma aurantifolia’ and related phytoplasmas. This is the first report of a phytoplasma disease of tenweeks stock. Considering that this Brassicaceae ornamental species is widely grown in Italy, it could play an important role in spreading these phytoplasmas, new for Italy
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