1,721,171 research outputs found
Multiplex reverse transcriptase-polymerase chain reaction applied to virus detection in globe artichoke
No full textSix specific primers were used for reverse transcription-amplification of parts of the genomic RNAs of artichoke mottled crinkle tombusvirus (AMCV), artichoke Italian latent nepovirus (AILV) and artichoke latent potyvirus (ALV) in artichoke plant sap. Each primer pair was highly specific for each viral RNA template and in multiplex reverse transcription-amplification reactions run independently, yielding products of the expected virus-specific size. The optimal artichoke plant sap dilution was about 10(3)-fold in 10 mM DTT and the optimal MgCl2 concentration was 2.25 mM. The detection limits for simultaneous amplification were of about 400 fg for AMCV and ALV and of about 4 pg for AILV. The method proved to be useful for simultaneous detection in cases of viral mixed infections which are likely to occur in nature
Nucleotide sequence of the 3'-terminal region of artichoke mottled crinkle tombusvirus RNA
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Nucleotide sequence of a satellite RNA of a strain of cucumber mosaic virus associated with a tomato fruit necrosis
No full textSynthesis of in vitro transcripts for the detection of artichoke mottled crinkle tombusvirus in artichoke
No full textEvolutionary dynamics of cucumber mosaic virus satellite RNA during natural epidemics in Italy
No full textThe evolutionary dynamics of 22 variants of cucumber mosaic virus satellite RNA (CMV satRNA) isolated in Italy during virus epidemics from 1988 to 1993 were investigated on the basis of their primary structure and biological properties. Most of the variants were amplified from total nucleic acid preparations extracted from field-infected plants, thus representing wild isolates of CMV satRNA. Eleven variants were associated with subgroup II CMV strains, 10 with subgroup I and 1 with a mixed infection by both strains. When inoculated onto tomato seedlings, the variants induced the phenotype (necrogenic or ameliorative) predicted by their nucleotide sequence. Phylogenetic relationships between the satRNA variants were determined using the stationary Markov model, a stochastic model for evolution. For each satRNA, the Markov analysis gave a good correlation between position in the phylogenetic tree and biological properties. The variants with ameliorative and necrogenic phenotypes in tomato followed two different evolutionary dynamics in nature. Tfn-satRNA, a 390-nt-long molecule, followed a third type of evolutionary dynamic far apart from that of the shorter satRNA molecules (i.e., those in the 334- to 340-nt-length class). Average values of the mean constant rate of nucleotide substitutions/site (K-subs/site) indicated that in nature the variants tend to keep their heterogeneity unchanged from one epidemic episode to the other, even if the outbreaks occur in places very far from each other. This seems to be in agreement with the proposed maintenance of a functional molecular structure as a constraint to CMV satRNA evolution. (C) 1997 Academic Press
Evolutionary dynamics of cucumber mosaic virus satellite RNA variants isolated during natural epidemics in Italy.
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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
Influence of autochthonous Saccharomyces cerevisiae strains on volatile profile of Negroamaro wines
No full textSaccharomyces cerevisiae is the yeast species predominating the alcoholic fermentation of grape must. The aim of this research was to evaluate the impact of indigenous S. cerevisiae strains biodiversity on the aroma of wines from Negroamaro grapes. Grapes collected in two different Negroamaro producing micro districts in Salento (Southern Italy), were subjected to natural fermentation and two indigenous S. cerevisiae populations were isolated. Fifteen strains for each of the two populations were selected and tested by micro fermentation assay in order to evaluate their specific contribute to the volatiles composition and sensory impact of the produced wines. The aromatic profile of wines obtained by each selected strain was characterized by different contents of acetates, ethyl esters of fatty acids, higher alcohols, thus showing to be related to the strains geographical origin. The sensorial analysis of wines produced by the six best performing strains confirmed that they are good candidates as industrial starter cultures, This study indicates that the use of a "microarea-specific" starter culture is a powerful tool to enhance the peculiarity of wines deriving from specific areas
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