1,720,985 research outputs found
Le malformazioni delle piante nell’iconografia: percorso storico-documentario
No full textPlant 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.
No full textTristeza 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
No full textIn 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Virescence of tenweeks stock associated to phytoplasma infection in Sicily
No full textIn 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
- …
