bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peanut Chlorotic Ringspot Virus (PCRV), a Newly Discovered Virus Infecting Peanut (Arachis hypogaea L.)
Authors: Wagih E. E. , Melouk H. A. , Sherwood J. L. 
Published: May 2008

AbstractA virus causing wide chlorotic ringspot (PCRV) associated with chlorotic line pattern and motthng on an Erictoides hybrid growing in USDA‐OSU greenhouses, Stillwater, Oklahoma, was discovered. The virus was isolated and characterized and found to differ in symptomology, host range and serological properties from all the previously described viruses infecting peanut, particularly those reported in the United States to be the most important ones, peanut mottle virus, peanut stripe virus, and tomato spotted wilt virus. The virus was transmitted by both mechanical inoctilation and grafting to fourteen peanut cultivars causing identical symptoms to those originally observed on the Erictoides hybrid. In addition to peanut, the virus systemically infected Pisum sativum L. ‘Little marvel’ causing mainly mosaic and Lupinus albus L. ‘Tiftwhite’ producing severe malformation and remarkable reduction in leaflet area. The virus did not infect many other plant species of which cowpea ‘California blackeye’ (Vigna unguiculata L.) and at least five cultivars of soybean (Glydne max L.) are known to be susceptible hosts to peanut mottle virus. Phaseolus vulgaris L. ‘Topcrop’ and Chenopodium amaranticohr Coste & Reyn were found to be two useful local lesion assay and diagnostic hosts for PCRV. The virus elicited necrotic local lesions on the first and chlorotic ringspots on the second. PCRV had a dilution end point between 10−5 and 10−6, thermal inactivation point between 55°C and 60°C, and longevity in vitro up to 6 days but not 7 days. Virus particles viewed hy electron microscopy and the negative stain uranyl aceute were flexuous filamentous particles ranging in length from 750–850 nm. In both indiren PAS‐ELISA and Ouchterlony double immunodiffusion test, PCRV was serologically related to a PMV isolate from Oklahoma (PMV‐OK.) but not to bean yellow mosaic virus, peanut stripe virus, potato virus Y, watermelon mosaic virus 1, watermelon mosaic virus 2, wheat streak mosaic virus, and zucchini yellow mosaic virus.
A Comparison of Polypeptides from Teliospores of Tilletia controversa (Kuhn) and Tilletia tritici (Bjerk) Wint.
Authors: Banowetz G. M. , Doss R. P. 
Published: May 2008

AbstractTeliospores from 12 races of Tilletia tritici (Bjerk.) Wint. and twelve isolates of Tilletia controversa (Kuhn) were sampled from field‐inoculated wheat (Triticum aestivum L.) differential cultivars. Proteins were extracted from the teliospores and analysed by one dimensional electrophoresis. An abundant 116 kD polypeptide detected in extracts from teliospores of all isolates of T. controversa was not detected in T. tritici teliospore extracts. Spores which were mechanically disrupted yielded greater quantities of the protein compared to intact teliospores, and this suggested the polypeptide was derived from within the teliospore. The presence of the polypeptide was correlated with dwarf bunt‐causing Tilletia‐ Isolates of dwarf bunt‐causing Tilletia that were intermediate between T. tritici and T. controversa in either morphology or germination characteristics contained the polypeptide while a common bunt‐causing race of T. tritici (T18) with intermediate characteristics lacked the protein. The 116 kD polypeptide present in all T. controversa isolates may provide a stable biochemical marker for identification of these teliospores in wheat shipments.
Development of Pseudocercosporella herpotrichoides (Fron) Deighton var. herpotrichoides and var. acuformis on Wheat Plants Measured by ELISA
Authors: Poupard P. , Grare S. , Cavelier N. , Lind V. 
Published: May 2008

AbstractUsing the ELISA method, the development of Pseudocercosporella herpotrtchoides var. herpotrichoides and var. acuformis in a susceptible cultivar of winter wheat was compared under controlled and held conditions. In the greenhouse, var. acufornis grew less vigorously, was slower in penetrating the coleoptile and the successive leaf sheaths and in colonizing the stem tissue than var. herpotrichoides. In the field, these differences were confirmed on the last leaf sheaths and the stem. At ripening stage, however, identical ELISA values were measured for both varieties. Moreover, a significant variation was observed between the individual isolates of each variety.Comparison of the effect of both varieties of P. herpotrichoides on 20 wheat cultivars characterized by different resistance levels showed significant interactions. The cultivars carrying the Pch‐1 gene always remained the less diseased genotypes. In general, var. acuformis developed less antigen in the cultivars than var. herpotrichoides. It is concluded, that in tests for resistance to P. herpotrichoides mixtures of many highly pathogenic isolates of both fungus varieties should be used. Less complex mixtures or single isolates may result in wrong estimates of resistance.
The Association of Discula destructiva (Red.) Hyphae With Cornus florida (L.) Trichomes
Authors: Brown D. A. , Windham M. T. , Graham E. T. 
Published: May 2008

AbstractDetached, surface‐dismfested flowering dogwood (Cornus florida L.) leaves were inoculated with a Discula destructiva (Red.) spore suspension in an effort to identify inoculation and pre‐penetration phenomena in the dogwood anthracnose pathosystem. Scanning electron micrographs show an association of D. destructiva hyphae with trichomes on the flowering dogwood upper leaf surface. The basal area of these leaf hairs may provide an entry point for Discula spp. colonization of and penetration into the dogwood leaf; however, the possible significance of this area as a unique ecological niche on the dogwood phylloplane should not be ignored.
Cytochemical Detection of Cell Wall Bound Peroxidase in Rust Infected Broad Bean Leaves*
Authors: Medeghini Bonatti P. , Lorenzini G. , Baroni Fornasiero R. , Nali C. , Sgarbi E. 
Published: May 2008

AbstractCell wall bound peroxidase activity, cytochemically detected by 3,3‐diaminobenzidine (DAB), appears unevenly distributed in areolae of broad bean (cv. Aguadulce) leaves infected by the rust fungus Uromyces viciae‐fahae (Pers.) Schroet. DAB positivity is not significantly traceable at the periphery of the areola and close to the site of uredinium formation; heavy DAB deposits occur on walls of haustoria containing mesophyll cells. Induction of localized peroxidase activity appears strictly related to the haustorium mother cell differentiation, i.e. to the incipient parasitic phase; it does not, however, counteract the intracellular growth of the haustorium.
Identification of a Strain of Peanut Chlorotic Streak Virus Causing Chlorotic Vein Banding Disease of Groundnut in India
Authors: Satyanarayana T. , Sreenivasulu P. , Ratna A. S. , Reddy D. V. R. , Nayudu M. V. 
Published: May 2008

AbstractA virus disease characterized by chlorotic vein banding, chlorotic line pattern along the margins or midrib of mature leaflets and chlorotic spots/rings was observed on commercial groundnut crops in Rayalaseema area of Andhra Pradesh with an incidence from 1% to nearly 60%. The virus was transmitted by mechanical inoculation in extracts prepared with 0.01 M potassium phosphate butter, pH 8.0 to 21 species from the Chenopodiaceae, Cruciferae, Leguminosae and Solanaceae, Chenopodium quinoa was found to be a good local lesion host. The virus was neither seed‐transmitted through 1591 groundnut seeds nor aphid‐transmitted by Aphis craccivora, Myzus persicae and Rhopalosiphum maidis either in non‐persistent or semi‐persistent manner. The virus remained infective in buffered tobacco leaf sap at a dilution of 10−5; in a 10−1 dilution of buffered sap the virus was infective for 2–3 days at 22–29°C or when heated to 65°C for 10 min but not to 70°C.Clarification treatments with organic solvents with 10% chloroform was least damaging. The virus was purified from Nicotiana rustica leaves. Purified virus contained isometric particles of 51 nm in diameter with an electron dense core of 22 nm and two major polypeptides of 76 kDa and 36 kDa. A polyclonal antiserum to this virus was produced. In agar gel double diffusion, enzyme‐linked immunosorbent assay and in electro‐blot immunoassay rests the virus was related to peanut chlorotic streak virus and not to cauliflower mosaic, figwort mosaic and soybean chlorotic mottle viruses.
Systems of Designation of Pathotypes of Plant Pathogens
Authors: Limpert Eckhard , Clifeord Brian , Dreiseitl Antonin , Johnson Roy , Müller Kaspar , Roelfs Aean , Wellings Colin 
Published: May 2008

AbstractTo name pathotypes of plant pathogens, a variety of systems of designation has evolved, which was evaluated to find out the systems best suited. Virulence and avirulence/virulence formulae of pathotypes are by far advantageous over the use of consecutive numbers or letters given in chronological order of pathotype discovery. As soon as pathotype information surpasses a certain level of complexity, mathematical codes are most advantageous and, in particular, octal notation and coded triplets (tripletcode). To ease communication and comparisons of results, a more universal adoption of the most appropriate codes is recommended.
Occurrence of Agrobacterium tumefaciens Biovar 3 on Grapevine in Brazil
Authors: De Oliveira J. R. , Da Silva Romeiro R. , De Souza Leäo Lacerda B. 
Published: May 2008

AbstractOccurrence of crown gall on grape was observed in a vineyard in Minas Gerais State, Brazil. Isolations of the pathogen yielded a bacterium which incited galls on grapevine, tomato and bryophillum. The bacterium was confirmed as Agrobacterium tumefaciens and its characterization showed it to be biovar 3. This is the first report on the occurrence of the biovar 3 of A. tumefaciens on grapevine in Brazil.
Characterization of Rhizoctonia solani associated with Sore Shin and Leaf Spot Symptoms on Tobacco in Zimbabwe
Authors: Mpofu S. I. , Julian A. M. 
Published: May 2008

AbstractThe relationship between Rhizoctonia solani isolates derived from leaf spot and sore shin symptoms on tobacco was characterized by determining nuclear number, hyphal diameter, anastomosis grouping (AG) and pathogenicity. The leaf spot isolates had significantly more nuclei per cell, and wider hyphae than the sore shin isolates. Anastomosis pairings with known tester strains confirmed the leaf spot isolates to be AG 3, and the sore shin isolates to be AG 4. Pathogenicity testing indicated that the leaf spot isolates were pathogenic to all parts of the plant, whereas the sore shin isolates tended to form lesions on stems only.
Serological Relationship and Chemical Composition of Exopolysaccharides (EPS) from Different Pathotypes of Xanthomonas campestris pv. Citri and Xanthomonas campestris pv. Manihotis
Authors: Bach E. E. , Guzzo S. D. 
Published: May 2008

AbstractThe exopolysaccharides (EPS) of five isolates of two pathotypes (A and C) of Xanthomonas campestris pv. citri and two isolates of X. campestris pv. manihotis have been isolated and partially characterized with regard to their sugar composition through gas chromatography. Results showed that except for one isolate of the pathotype C of X. campestris pv. citri which lacks galactose in its EPS, all the others are qualitatively identical in their sugar composition. However, quantitative differences were observed within and among the different isolates. Serological reactions among the different isolates showed that pathotype A of X. campestris pv. citri reacts only with the isolates of X. campestris pv. manihotis, while these also react with one of the isolates of pathotype C of X. campestris pv. citri. However, the isolate of pathotype C is cross‐reactive with the other isolate of the same pathotype which does not react with X. campestris pv. manihotis. This suggests a new pathogenic variant of pathotype C in Brazil, serologically distinct of the other isolates at least regarding the serological relationship with X. campestris pv. manihotis. Data did not permit any conclusion concerning the relationship between the sugars of each EPS and the serological recognition among the isolates.
Inhibition of Potato Spindle Tuber Viroid (PSTVd) Infectivity with Antisense RNA Transcripts
Authors: Matoušek J. , Trněná L. , Rakouský S. , Riesner D. 
Published: May 2008

AbstractAntisense RNA was mixed with natural potato spindle tuber viroid (PSTVd) at 200‐fold molar excess and hybridized in vitro before inoculation of tomato plants. Inhibition of viroid infectivity was then characterized by percent infected plants of inoculated plants (percent of infectivity) and amount of PSTVd in infected leaves. For short RNA complementary to nucleotides 42–78, the inhibitory effect was much lower than for the corresponding antisense DNA oligonucleotides under the same experimental conditions. An almost complete block of PSTVd infection was observed, however, using complete minus monomers of PSTVd, suggesting that double stranded PSTVd RNA is not infectious. For antisense RNA complementary to nucleotides 338–359/1–87, 264–359/1–94, and 88–337, percent of infectivity was 67%, 8% and 17% and levels of PSTVd relative to control (100%) were 48%, 20% and 35%, respectively. Double stranded complexes formed between PSTVd and antisense RNAs were detectable using antibody specific fordouble stranded RNA and the sizes of the double‐stranded stretches were estimated using a nuclease S1‐protection assay. It was found that double‐stranded RNA was formed during co‐transcription of antisense RNA and PSTVd monomers of plus polarity at 37°C, and, to a lesser extent, during hybridization of antisense RNA and PSTVd monomers at lower temperature (after initially heating the samples to 40°C). In addition, antisense RNA inhibited infectivity of dimeric PSTVd transcripts of plus polarity with high efficiency if added during transcription. Co‐transcription of PSTVd dimers with antisense RNAs yielded RNA species showing virtually no infectivity. Nuclease S1‐protection assays revealed double‐stranded RNAs having lengths predominantly in the range, of the corresponding antisense RNAs.
Effect of Rust Infection on Cell Walls of Barley and Wheat; Immunocytochemistry Using Anti‐Barley Thionin as a Probe
Authors: Ebrahim‐Nesbat F. , Rohringer R. , Heitefuss R. 
Published: May 2008

AbstractPolyclonal antiserum prepared against barley cell wall thionin was used to localize and quantitate immunoreactive material on the cellular level in healthy and rust‐infected leaves of barley and wheat. Three types of sites were used for the immunocytochemical analysis: as control sites, mesophyll cell walls were selected in uninoculated leaves, and in leaves that were inoculated with rust but where the sites were not in contact with the pathogen: these were compared with mesophyll cell walls that were in contact with intercellular rust hyphae in inoculated leaves.Similar amounts of cell wall thionin were detected in all 3 barley cultivars before inoculation. At sites where intercellular hyphae of Puccinia hordei had made contact with mesophyll cell walls, less thionin was found in the compatible host cv. Larker, but in incompatible hosts (cvs. Gold and Bolivia) the thionin concentration did not differ from that of the controls.Two cultivars of wheat were studied with respect to immunoreactive material in their mesophyll cell walls, the universal rust suscept cv. Little Club and the highly rust‐resistant cv. Khapli. Before inoculation, leaves of cv. Khapli contained about twice the amount of immunoreactive material in mesophyll cell walls than those of cv. Little Club. This relation was unchanged in walls that had made contact with P. graminis tritici, but in non‐contacted walls of infected cv. Little Club leavest, he concentration of this material had risen to levels typical for those of cv. Khapli. Tests for immunoreactive material with pre‐embedding cytochemistry yielded negative results, indicating that it is not exposed on the surface of mesophyll walls in barley and wheat.
Inhibition of Imidazolegly cerolphosphate Dehydratase of Phytophthora Parasitica by Aminotriazole in situ and after Cloning and Expression of the Respective Gene (HIS3) in Escherichia coli
Authors: Karlovsky P. 
Published: May 2008

AbstractThe HIS3 gene of Phytophthora parasitica was isolated from a plasmid library by complementing E. coli his B463 to histidine prototrophy. The gene, encoding imidazolegly cerolphosphate dehydratase, was expressed in E. coli independently of the promoter of the cloning vector. The growth of Phytophthora parasitica was far more sensitive to 3–amino–1,2,4–triazole (amitrole) than that of the E. coli w.t. The inhibition was fully counteracted by histidine. E., coli with a defective imidazoleglycerolphosphate dehydratase complemented by the Phytophthora gene exhibited the same high sensitivity against amitrole as Phytophthora itself. The expression of genes in E. coli is suggested for, screening potential inhibitors of enzymes in pathogenic organisms.
Reactivity of Two Monoclonal Antibodies to the Cylindrical Inclusion Protein of Potato Virus Y
Authors: Boudazin G. , Vergnet C. , Gélie B. , Meyer M. , Grosclaude J. , Maury Y. 
Published: May 2008

AbstractMonoclonal antibodies (mAbs) were produced to the cylindrical inclusion (CI) protein of a necrotic strain of potato virus Y (PVY‐N) and their reactivity tested with nine PVY isolates and 12 other potyviruses. mAb 95 showed a reactivity range larger than PVY, unlike mAb 88 which only recognised the PVY isolates. Moreover, immunogold labelling of the Cls of PVY‐N, either in situ or in cell extracts, was only obtained with mAb 88, thus showing that the corresponding virus‐specific epitope is located at the surface of the Cl polymer.
Invasiveness of Avirulent Strains of Pseudomonas solanacearum in Tomato Cultivars, Resistant or Susceptible to Bacterial Wilt
Authors: Grimault V. , Prior P. 
Published: May 2008

AbstractTomato plant colonization by avirulent strains of Pseudomonas solanacearum was studied. The strain 8217R a spontaneous rough mutant was able to penetrate into roots by nature opennings and colonize plants at high levels. The strain 8173, a hrp‐ engineered fluidal mutant, colonized the plants to a lesser extent than 8217R. There was no difference in colonization observed at taproots and hypocotyls between resistant and susceptible cultivars with the avirulent strains 8217R and 8173, contrary to the plant‐virulent strain interaction. Results indicated that the bacterial spread was limited in the two cultivars regardless of their resistance or susceptibility and suggested the existence of a host defence mechanism, limiting the bacterial spread.
Development and Evaluation of a Laboratory‐Based Technique for Screening Somaclonal Regenerants of Watercress (Rorippanasturtium‐aquatium) for Resistance to Crook Root Disease (Spongospora subterranea f. sp. nasturtii)
Authors: Arnold D. L. , Flegmann A. W. , Clarkson J. M. 
Published: May 2008

AbstractA laboratory based method has been developed for infecting watercress with the crook root fungus (Spongospora subterranea f.sp. nasturtii). This utilised plastic trays of nutrient solution on which watercress shoots, supported by floats, were grown for a pre‐inoculation period of 14 days before an inoculum consisting of 1 g of crook roots was added. Seven watercress someclones derived from plantlets regenerated from callus of a parental commercial control line (clone A) were tested onthree separate occasions. No variation within the parental control plants was seen but significant variation both between and within the individual somaclones over successive tests was observed. Two somaclones showed increased resistance to crook root disease compared with parental control plants.
Expression of Resistance to CMV Migration in Pepper Seedlings
Authors: Dogimont C. , Daubeze A. M. , Palloix A. 
Published: May 2008

AbstractPrevious studies have shown that the partially resistant genotypes of pepper (Capsicum annuumL.), ‘Milord’ and ‘Vania’ are able to localize CMV infection in some shoots of the plants when inoculated at an adult stage. We have observed that the virus migration is restricted to the inoculated cotyledons when young seedlings of these genotypes are inoculated with the Fulton CMV/N strain. In the same conditions, susceptible genotypes become systematically infected. We have shown that the levelof resistance expression depends on the plant development stage, the environmental conditions and the inoculum concentration. The most favourable conditions to discriminate resistance to CMV migration at an early stage of plant development have been defined.
Differential Sensitivity of Wheat Embryos against Extracts Containing Toxins of Septoria nodorum: First Steps towards in vitro Selection
Authors: Keller B. , Winzeler H. , Winzeler M. , Fried P. M. 
Published: May 2008

AbstractAs a first step towards the development of an in vitro‐selection system for septoria nodorum blotch resistance, wheat embryo culture on media containing extracts from Septoria nodorum was established. Extracts prepared from inoculated wheat grains had a toxic activity. Control extracts from uninoculated grains showed at least a 10‐fold lower toxic activity. Two wheat breeding lines susceptible to Septoria nodorum showed reduced growth in the presence of the fungal extract whencompared to a breeding line known to have good resistance in the field. A test with seven additional wheat lines showed a good agreement between field resistance of the ear and embryo resistance. Mellein is one of the toxins produced by Septoria nodorum and was used in pure form for in vitro‐selection. It showed toxic effects at 50 μg/ml, a concentration which is about 200‐fold higher than the mellein concentration in the diluted extract with embryotoxic activity. This indicates the importance of additional toxic compounds in the crude extract. Mellein acted non‐selectively on embryos of the different cultivars.
Effect of Host‐race Combination on Resistance of Sunflower, Helianthus annuus L., to Downy Mildew Plasmopara balstedii
Authors: Mouzeyar S. , de Labrouhe D. Tourvieille , Vear F. 
Published: May 2008

AbstractStudy of resistance of sunflower, Helianthus annuus L., to downy mildew, Plasmopara halstedii, shows that both susceptible and resistant seedlings are always infected by the fungus, then hypersensitive‐like reactions occur in the parenchyma and necroses form around the parasite. Comparison of 21 incompatible combinations (resistance) shows that the extent of the fungus growth differs according to the host‐race combination. With type I resistance, the fungus is limited to the roots andthe lower part of the hypocotyl. With the type II resistance, the fungus grows throughout the whole length of the hypocotyl and may sporulate on the cotyledons.
Genetic Variability in Pectic Enzymes of Rhizoctonia solani Isolates Causing Bare‐patch Disease of Cereals
Authors: Yang H. A. , Zhou J. , Sivasithamparam K. , Tommerup I. C. , Barton J. E. , O'Brien P. A. 
Published: May 2008

AbstractField isolates of Rhizoctonia solani obtained from three discrete bare patches in a wheat field in Western Australia were characterized by pectic zymogram grouping. The genetic background of pectic enzymes was analysed by comparing the zymograms of asexual homokaryons and sexual progenies derived from field isolates. The 170 field isolates obtained from the field site produced indistinguishable pectic zymograms. However, variations among field isolates of the same zymogram group were detected, on the basis of zymograms of their resultant protoplast‐regenerated cultures. Asexual sibling homokaryons derived from each of the field isolates were heterogeneous for their pectic enzymes. Homokaryons with a common heterokary on incompatibility factor, obtained from a field isolates were homogeneous for pectic enzymes. Basidiospore progenies of a field isolate segregated widely in pectic zymograms. It appeared that the expression of pectic enzymes by field isolates involved multiple genetic factors. The variation of zymograms among homokaryotic strains suggests that each field isolate of R. solani contains two types of nuclei, although cells of vegetative hyphae are multinucleate.