1,720,997 research outputs found
Improving biocontrol activity of Pichia guillermondii against post-harvest decay of oranges in commercial packing-houses by reduced concentrations of fungicides
No full textDNA biosensors for the detection of aflatoxin producing Aspergillus flavus and A. parasiticus
No full textCharacterisation of isolates of Phoma tracheiphila by RAPD-PCR, microsatellite-primed PCR and rDNA ITS1/ITS2 sequencing and development of specific primers for in planta detection
No full textDifferential gene expression during the pathogenic interaction between Pichia fermentans and peach fruit
No full textA biofilm-forming strain of Pichia fermentans was found to be a very strong antagonist against brown rot and grey mold in artificially wounded apple fruit when co-inoculated with either Monilinia fructicola or Botrytis cinerea, respectively. The same strain of yeast, however, was an aggressive pathogen when inoculated on peach fruit, causing rot of fruit tissues, even in the absence of other pathogens. Optical and scanning electron microscopy showed that P. fermentans produces only yeast-like shaped cells during colonization of apple tissue, while exhibiting pseudohyphal growth on peach tissue. A rapid subtractive hybridization approach (RaSH) was used to identify differentially expressed genes in the pathogenic form of P. fermentans by comparing the cDNA of P. fermentans sampled after 24 hours growth on apple with the cDNA of the same strain grown 24 hours on peach fruit. A total of 450 clones were analysed by a reverse Northern Blotting technique, yielding some fragments which were significantly expressed on peach but less on apple tissue. These sequences were compared to the available genome sequences of another dimorphic yeast, Candida albicans, and homologous genes were identified. The relationship between these genes, dimorphism, and pathogenicity will be discussed
Synthesis of natural-like hydroxylated biphenyls: an interesting class of bioactive agents.
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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
Molecular characterisation of vegetative compatibility groups in Fusarium oxysporum f. sp radicis-lycopersici and f. sp lycopersici by random amplification of polymorphic DNA and microsatellite-primed PCR
No full textRandom amplification of polymorphic DNA (RAPD-PCR) analysis was conducted on 48 isolates of Fusarium oxysporum f. sp. radicis-lycopersici (F.o.r.l.) from different geographic regions, representing all known vegetative compatibility groups (VCGs) except VCG 0097 and VCG 0099 and on eight isolates of F.oxysporum f. sp. lycopersici (F.o.l.), representing VCGs 0030, 0031, 0032 and 0033. Upon UPGMA (unweighted pair-group method with arithmetic averages) analysis of 86 RAPD-PCR markers generated by 16 informative primers and 44 markers obtained with eight microsatellite primers, a close relatedness was evident for F.o.r.l. isolates in VCGs 0090, 0092, 0096, and, to a lesser extent, for those in VCG 0093. Representatives of VCG 0091 formed a distinct group, while F.o.r.l. isolates in VCGs 0094 and 0098 were not distinguishable by the tested markers, most of which were also shared by F.o.l. isolates belonging to VCGs 0031 and 0033. F.o.l. isolates in VCGs 0030 and 0032 shared most of the molecular markers. The correlation between RAPD-PCR and microsatellite genetic distance was highly significant (R-2 = 0.77; P by Mantel test < 0.001). The molecular variability observed in both formae speciales is discussed in relation to the development of F.o.r.l.- and F.o.l.-specific diagnostic tools
Identification of potential marker genes for Trichoderma harzianum strains with high antagonistic potential against Rhizoctonia solani by a rapid subtraction hybridization (RaSH) approach
No full textFusarium species and chemotypes associated with Fusarium Head Blight and Fusarium Root Rot on wheat in Sardinia
Full text linkEnvironmental conditions in Sardinia (Tyrrhenian Islands) are conducive to fusarium root rot (FRR) and fusarium head blight (FHB). A monitoring survey on wheat was carried out from 2001 to 2013, investigating relations among these diseases and their causal agents. FHB was more frequently encountered in the most recent years while FRR was constantly present throughout the monitored period. By assessing the population composition of the causal agents as well as their genetic chemotypes and EF-1 polymorphisms, the study examined whether the two diseases could be differentially associated to a species or a population. Fusarium culmorum chemotypes caused both diseases and were detected at different abundances (88% 3-ADON, 12% NIV). Fusarium graminearum (15-ADON genetic chemotype) appeared only recently (2013) and in few areas as the causal agent of FHB. In F.culmorum, two haplotypes were identified based on an SNP mutation located 34bp after the first exon of the EF-1 partial sequence (60% adenine, 40% thymine); the two populations did not segregate with the chemotype but the A-haplotype was significantly associated with FRR in the Sardinian data set (P=0001), suggesting a possible fitness advantage of the A-haplotype in the establishment of FRR that was neither dependent on the sampling location nor the sampling year. The SNP determining the Sardinian haplotype is distributed worldwide. The question whether the A-haplotype segregates with characters facilitating FRR establishment will require further validation on a specifically sampled international data set
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