bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scanning Electron Microscopy of Apothecia of Sclerotinia trifoliorum Erikss. and Related Species
Authors: Arseniuk E. , Macewicz J. 
Published: May 2008

AbstractThe technique of scanning electron microscopy (SEM) was used to study the microanatomy of apothecia of Sclerotinia trifoliorum Erikss., S. sclerotiorum (Lib.) de Bary, and S. minor Jag., In the sterile tissue zones of apothecia, the only interspecific difference detected was that one in the structure of the apothecial margin of small‐ and large‐sclerotium Sclerotinia spp., The ectal excipulum, at the apothecial margin in S. minor appeared to be comprised of textura globulosa with globose cells. Whereas, in S. trifoliorum and S. sclerotiorum it appeared to be comprised of textura porrecta with prosenchymatous cells.The other interspecific difference reported in this paper is a dimorphism in spore size (ratio 4:4) in asci of S. trifoliorum. Otherwise, the microanatomy of ascocarps of S. trifoliorum and S. sclerotiorum was identical to that one of S. minor. Differences in the density of hyphae in the medullary excipulum in the apothecial disks of the three species studied were not detected. The presence of a membranous film over the hymenium of the ascocarp of S. trifoliorum or, any other species, as well as the bundlelike structure of the apothecial stipes in the studied species, as described in earlier reports, was also not found.
Isolation and Partial Characterization of Peanut Top Paralysis Virus (PTPV), a Destructive Virus Causing a New Disease in Peanut (Arachis hypogaea L.)
Authors: Wagih E. E. , Melouk H. A. , Sherwood J. L. 
Published: May 2008

AbstractA destructive virus, causing top paralysis to peanut, was discovered in the wild germplasm collection growing in the USDA‐ARS greenhouses, Stillwater, Oklahoma, USA. The symptoms observed on the wild plant were restricted to a few leaves as green batches in a light green to yellow background with some leaflets having lost most of the basal part of the laminae leaving the top portion rolling upwards forming a cone. The virus was mechanically transmitted to cultivated peanut (Arachis hypogaeaL,.) where it caused more severe and destructive symptoms including stunting, severe malformation of leaves and partial or complete disappearance of leaflet laminae. This virus differed in symptomology, host range, and/or serological reactivity from allpeanut viruses reported in the literature, particularly those causing leaf malformation and stunting. The virus induced necrotic local lesions on Phaseolus vulgaris L. cv. “Topcrop” and chlorotic local lesions with necrotic centres bordered withvery bright intense red color on Chenopodium amaranticolor. In both passive indirect enzyme‐linked immunosorbent assay (PAS‐ELISA) and Ouchterlony double immunodiffusion test, the virus did not react with antisera against brome mosaic, bean yellow mosaic, peanut stripe, potato Y, tobacco mosaic, watermelon mosaic 1, watermelon mosaic 2, wheat soilborne mosaic, wheat streak mosaic, and zucchini yellow mosaic viruses.However, in reciprocal cross reactions the virus seemed to share a common antigenic determinant with a peanut mottle virus isolate from Oklahoma (PMV‐OK). The virus had flexuous filamentous particles with a length of 750–850 nm, falling within the range reported for the potyvirus group. The virus was successfully purified and the molecular weight of its protein subunit was found to be 30000 d. A polyclonal antiserum was raised in rabbits against the virus and used for reciprocal serological tests.
Broad Spectrum Detection of Cucumber Mosaic Virus (CMV) Using The Polymerase Chain Reaction
Authors: De Blas C. , Borja* M. J. , Saiz M. , Romero J. 
Published: May 2008

AbstractPrimers complementary to conserved sequences of cucumber mosaic virus (CMV) RNA 3 were designed and reverse transcription‐polymerase chain reaction was directly performed in crude sap extracts of CMV‐infected plants. All isolates assayed belonging to subgroups I or II from different Spanish geographical locations and infecting tobacco, tomato and cucumber plants were detected. No amplification was observed in healthy or tomato aspermy virus (TAV)‐infected plants, nor in CMV‐infected pepper plants.A, dilution as low as 10‐7 in tobacco crude sap extracts or 100 fg of purified virus (c. 50 000 virus particles) could be detected, results showing that this procedure is 102 times more sensitive than enzyme‐linked immunosorbent assay (ELISA).
Grafting Tomato Cultivars Resistant or Susceptible to Bacterial Wilt: Analysis of Resistance Mechanisms
Authors: Grimault V. , Prior P. 
Published: May 2008

AbstractGrafting experiments were carried out in order to understand tomato resistance mechanisms to Pseudomonas solanacearum. Resistant scions grafted on susceptible root‐stocks wilted, indicating that vascular tissues of resistant cultivars were not tolerant to higher bacterial populations than susceptible ones. Colonization frequencies and bacterial densities observed in plant grafted on resistant or susceptiblle root‐stocks showed that resistance was correlated to the limitation of bacterial spread in the lower part of the stem.
Induction of Growth Increase and Systemic Resistance to Exserohilum turcicum in Maize by Foliar Spray of Phosphates
Authors: Reuveni R. , Reuveni M. , Agapov V. 
Published: May 2008

AbstractA single foliar spray of 0.1 M solution of phosphate salts on the upper side of maize (cv. ‘jubilee') leaves 1, 2 and 3 at the 5–6 fully–expanded leaf‐stage, 2‐4 h before inoculation induced systemic resistance to northern leaf blight caused by Exserohilum turcicum. Nine days after challenge, protection was demonstrated by 91% reduction in the size and 69% in the number of E. turcicum lesions developing on leaves 4, 5, 6 and 7. Appropriate mixing of phosphate solution with KOH revealed that the level of protection was not necessarily dependent on the pH of the solution. The size and number of lesions decreased to 62% and 56%, respectively, 12 days after challenge. There was no damage or chlorotic stipling on the induced leaves (1, 2, and 3) as a result of the phosphate spray. There were no significant differences in the reduction in the number or size of the lesions obtained when the foliar spray was applied 2‐4 h or 1, 3, 6, 8, or 10 days before inoculation. One foliar spray ofK2HPO4 on leaves 1, 2 and 3 in these intervals before inoculation, remarkably stimulated growth of inoculated plants, which was expressed by several parameters. The possible dual use of phosphate salts as foliar fertilizers and as resistance‐inducing agents is discussed
Licht‐ und elektronenmikroskopische Untersuchungen zur Wirkung eines Kulturfiltrates von Erwinia herbicola B 247 und von Herbicolin A auf Fusarium culmorum
Authors: Kempf H.‐J. , Ebrahim‐Nesbat F. , Wolf G. 
Published: May 2008

Abstract Light and electron microscopical studies on the effect of a culture filtrate of Erwina herbicola B 247 and herbicolin A on Fusarium culmorum The effect of a culture filtrate of Erwinia herbicola B 247 and the antibiotic herbicolin A, respectively, on the hyphae of Fusarium culmorum was studied in vitro using light and electron microscopy. The light microscopy revealed a swelling and disruption of the hyphae tips with a release of cytoplasm. Ultrastructural investigations demonstrated the appearance of electron‐dense material of a round or tubular structure in the cell wall. On its inner side, an accumulation of electron‐dense material formed a spongy structure associated with the altered plasma membrane. Finally, a complete dissolution of the cell wall was observed.
Characterization of an Isolate of Zucchini Yellow Mosaic Virus form Cucumber in Singapore
Authors: Wong S. M. , Chng C. G. , Chng C. Y. , Chong P. L. 
Published: May 2008

AbstractZucchini yellow mosaic virus (ZYMV) was first found in cucumber in Singapore in 1989. This virus was propagated in Cucurbita pepo cv. First Taste and mechanically transmitted to 12 species of six families. It induced milder symptoms than the Connecticut and Florida strains of ZYMV in infected leaves of C. pepo cv. Zucchini Elite. ZYMV‐S is neither seed nor aphid transmissible. Immunoelectron microscopy revealed that ZYMV‐S is distantly related to WMV‐2, Moroccan WMV, and TelMV, but not, related to PRSV or ZYFV. Cytoplasmic pinwheels and scrolls were observed in ultrathin sections of infected leaf cells by light, confocal laser scanning, and transmission electron microscopy. The molecular weights of the viral coat protein and cytoplasmic inclusion protein, RNA and dsRNA were estimated to be 3.2 × 10−1, 6.1 × 104, 3.23 × 106 and 6.53 × 106 daltons, respectively.
Detection of Double‐Stranded RNA (DSRNA) in Crude Extracts of Virus‐Infected Plants by Indirect ELISA
Authors: Aramburu J. , Moreno P. 
Published: May 2008

AbstractAn antiserum against polyinosinic‐polycytidylic acid (In‐Cn) was used to detect double‐stranded RNA (dsRNA) by indirect ELISA (ELISA‐I). DsRNA from cucumber mosaic virus (CMV) and plum pox virus (PPV)‐infected plants was detected using different types of extracts. The pH of the extraction buffer was very important in dsRNA detection, the highest optical density values being obtained at pH 6 or in aqueous extracts. Extracts heated at 80°C for 2 min showed increased optical density values compared with unheated extracts. DsRNA from Nicotiana benthamiana plants infected with each of six PPV isolates was readily detected by ELISA‐I 50 days after inoculation. ELISA values then obtained with the In‐Cn antiserum were generally higher than those obtained by double antibody sandwich ELISA using an antiserum to virus coat protein. Purified dsRNA from the same infected plants showed no visible band, but it produced a fluorescent background when analysed by polyacrylamide gel electrophoresis.
Quick Decline of Macadamia Trees: Association with Phytophthora capsici
Authors: Ko W. H. , Kunimoto R. K. 
Published: May 2008

AbstractSome macadamia trees in commercial orchards in Hawaii showing quick decline syndrome had bleeding from the trunk. Phytophthora capsici was isolated from c. 67% of such sites, and was shown to kill branches of artificially‐inoculated healthy macadamia trees. The pathogen was detected in both diseased and apparently healthy bark and isolated from wood 80 mm away from the bark. Results suggest that trunk infection by P. capsici may lead to girdling and rapid decline, and attract insects which then cause some bleeding by making wounds at the sites of recent infection.
Cross‐Reactive Antigens Between Pea and Some Fungal Plant Pathogens
Authors: Scala F. , Cristinzio G. , Coppola L. , Del Sorbo G. 
Published: May 2008

AbstractAntiserum to pea was used to analyse cross‐reactive antigens (CRA) between pea and some fungal plant pathogens with different levels of specificity towards this host by using both double diffusion and immunoblotting techniques. Non pathogens of pea were also included in the study. Nectria haematococca MPVI, the three formae speciales dianthi, lycopersici and pisi of Fusarium oxysporum and Ascochyta pisi produced strong reactions with both techniques. In N. haematococca MPI, F. solani f. sp. phaseoli, V. dahliae and Phoma medicaginis var. pinodella instead, reactions were not detected by double diffusion but only the more sensitive immunoblotting technique. No CRA were observedin, the non‐specific pathogens Rhizoctonia solani, Sclerotium rolfsii and Sclerotinia sclerotiorum, as well as in the non‐pathogen Phytophthora capsici. The immunoblotting patterns of the most reactive fungi showed common bands with molecular weights of 84, 75 and 62 kDa. Some bands were present only in the specific pathogens N. haematococca MPVI and F. oxysporum f.sp. pisi. The possible involvement in host‐parasite interactions of cross‐reactive antigens which are, present in the analyzed fungi is discussed.
Cytopathology of Anthers and Pollen From Lettuce Plants Infected by Lettuce Mosaic Virus
Authors: Hunter D. G. , Bowyer J. W. 
Published: May 2008

AbstractThin sections of mature anthers and pollen grains from three lettuce (Lactuca sativa) plants infected with lettuce mosaic potyvirus (LMV) were studied by immunogold labelling. Labelled LMV particles were present externally on the exine of pollen grains from all plants, but were observed internally in the pollen grains from only one plant. Within mature pollen grains the virus particles were associated with the cytoplasmic bundle inclusions typical of infection by potyviruses. The tapetal plasmodium and the epidermal and endothecial layers of mature anthers from all infected plants also contained labelled virus particles, together with pinwheel and bundle inclusions.
Partial Characterization of a Gene for a 31 kD Protein of Pseudomonas syringae pv. syringae Apparently Involved in Pathogenicity
Authors: Niepold F. , Nickel Antje , Landsmann J. 
Published: May 2008

Abstract P. syringae pv. syringae strain R32 causes the bacterial brown spot disease on bush beans. A 31 kD protein was detected which is involved in the pathogenic response. Monospecific antibodies directed against this 31 kD‐protein were used to screen a protein expression gene bank made from the wild type strain R32. A 0.8 kb DNA insert of a clone which gave a positive reaction with the monospecific antibodies was used in hybrizations to clone a larger chromosomal fragment. A km‐cassette (kmresistance) was integrated into this chromosomal DNA‐fragment preventing the expression of the 31 kD‐protein. This construct was integrated into the chromosomal of the wild type strain R32 viahomologous recombination resulting in the 31 kD‐protein deficient mutant LMI. Biotests with the host plant (bean) and with tobacco leaves showed no symptoms or hypersensitive reaction (HR) when the mutant LMI was inoculated. However, atypical chlorotic and necrotic lesions compared to the wild type strain R32 were found on tobacco leaves when the mutant LMI was incubated for more than 2 weeks. Complementation of the LMI mutant with a plasmid harbouring the corresponding wild type R32 DNA fragment resulted in an isolate (LMIC) which showed a partial restoration of the HR on tobacco but no brown spot disease symptoms on bush beans. The 31 kD‐protein could be detected serologically in LMIC.
Comparison of Three Methods for Assessing Plum Pox Virus Variability: Further Evidence for the Existence of Two Major Groups of Isolates
Authors: Bousalem M. , Candresse Th. , Quiot‐Douine L. , Quiot J. B. 
Published: May 2008

AbstractTwenty‐eight plum pox virus isolates from several European and Mediterranean countries were compared by electrophoretic mobility of their coat protein subunit measured by Electroblot Immuno‐Assay (EBIA), antigenic properties of the N‐ and C‐terminal parts of the coat protein and restriction fragment length polymorphism (RFLP) and analysis of polymerase chain reaction (PCR) amplification of the C‐terminal part of the coat protein gene. Similar results were obtained by each of the three methods. These confirm the existence of the two major subgroups of PPV, and which we now propose to designate PPV‐D and PPV‐M, respectively.
Variability of Xanthomonas Campestris pv. vasculorum From Sugarcane and Other Gramineae in Reunion Island. Characterization of a Different Xanthomonad
Authors: Péros J. P. , Girard J. C. , Lombard H. , Janse J. D. , Berthier Y. 
Published: May 2008

AbstractStains presumed to be of Xanthomonas campestris pv. vasculorum (Cobb.) Dye, obtained from sugarcane and other gramineae in Réunion Island, were compared in terms of cultural aspects, pathogenic and physiological reactions, fatty acid profiles and restriction fragment length polymorphism (RFLP) of genomic DNA. The strains could be divided into two separate groups (G1 and G2). The G1 strains were identical to strains described as X. campestris pv. vasculorum; they showedan important variability in their cultural characteristics and in their aggressiveness. The G2 strains did not induce the usual symptoms of gumming disease on sugarcane cultivars infected under natural conditions or inoculated in the greenhouse. The G2 strains grew faster on agar medium, their colonies were more pigmented and less fluidal and had a different morphology on agar slant. Unlike the G1 strains, G2 strains hydrolyzed starch weakly and casein strongly; they utilized L‐fucose and, to a lesser extent, melibioze. The fatty acid and genomic DNA profiles differed between the groups. Differences seemed large enough to support separation of G1 and G2 strains into distinct taxonomic entities, namely G1 as Xanthomonas campestris pv. vasculorum and G2 as a different pathovar of X. campestris. The taxonomic position of G2 strains is discussed.
Angular Leaf Spot of Iron Wood Incited by a Pathovar of Pseudomonas syringae
Authors: Rahimian H. 
Published: May 2008

AbstractA fluorescent pseudomonad inciting brown angular leaf spots on iron wood (Parotia persica) in Mazandaran forest was isolated and identified as a pathovar of Pseudomonas syringae. Strains assimilated adonitol and L‐tartrate but not lactate or D‐tartrate as carbon sources for growth. The electrophoretic profiles of cell proteins of strains isolated from iron wood were very similar but differred markedly from protein profile of P. syringae pv. syringae.
New Races of Sunflower Downy Mildew (Plasmopara Halstedii) in Germany
Authors: Spring O. , Miltner F. , Gulya T. J. 
Published: May 2008

Abstract Plasmopara halstedii, the causal agent of downy mildew of cultivated sunflower (Helianthus annuus), was documented in Germany for the first time in commercial fields. The pathogen was first observed in the Württemberg area, where races 1 and 4 were identified using a set of differential lines. Later, commericial fields near Baden were found to be infected by race 5, which is the first occurrence of that race outside of North America. Withthe discovery of race 5, there are now eight races of the sunflower downy mildew fungus that have been found in Europe. The sunflower cultivars most frequently grown in Germany were investigated for resistance to race 1, 4 and 5; while all were resistant to race 1, none were resistant to either race, 4 or 5.
Occurence of grapevine chrome mosaic nepovirus in Austria
Authors: Dimou D. , D'Onghia A.M. , Laimer da amara Machado M. , Savino V. 
Published: May 2008

AbstractA virus recovered by inoculation of sap from Austrian vines with yellow mosaic symptoms was compared with, and found virtually indistinguishable from, an authentic Hungarian isolate of grapevine chrome mosaic nepovirus. This seems to be the first record of the virus in Austria.
Induction of Resistance or Susceptibility in Pea to Races of Pseudomonas syringae pv. pisi
Authors: Akpa A. D. , Archer S. A. 
Published: May 2008

AbstractThe phenomena of induced resistance and induced susceptibility were investigated in the pea‐Pseudomonas syringae pv. pisi system, using two pea cultivgars, Early Onward and Hurst Green Shaft, and races 1 and 2 of the pathogen. Preliminary treatment with heat‐killed bacteria induced resistance in peas to infection by P. s. pv. pisi; the resistance induced was dependent on the time interval between the preliminary and challenge inoculations. The mechanism of induced resistance appears to vary between the cultivars. Similarly, both races of the pathogen appear to have different resistance‐inducing efficiencies. Resistance in cvs Early Onward and Hurst Green Shaft to the compatible bacterium could not be induced by preliminary inoculation with live cells of an incompatible race. Heat‐killed cells of the races failed to induce the hypersensitive reaction in cultivars that normally show this response when challenged with live avirulent bacteria. Preliminary inoculation with live race 1 cells failed to induce susceptibility in cv. Early Onward to live race 2 cells, irrespective of the challenge inoculation interval. On cv. Hurst Green Shaft, however, preliminary inoculation with live race 2 cells induced limited susceptibility to live race 1 cells. Preliminary treatment with sterile distilled water followed by challenge of the same leaves 24 h later with a compatible race induced a moderate resistance response in both cultivars.
Patterns of protein synthesis in infected and stressed sugar beet (Beta vulgaris L.)
Authors: Coutts R. H. A. , Linton D. J. , Bolwell G. P. 
Published: May 2008

AbstractPatterns of protein synthesis have been investigated in infected and stressed sugar beet roots and suspension cultured cells by two‐dimensional, iso‐electric focussing/sodium dodecyl sulphate polyacrylamide gel electrophoresis. Comparisons have been made between the protein complement of dormant field‐grown sugar beet roots and rhizomania‐infected roots originating from a UK outbreak, hydroponically grown, uninfected control and Polymyxa betae‐infected sugar beet seedlings and control, biotic and abiotic elicitor‐treated sugar beet suspension cultured cells. Rhizomania‐infected roots and elicitor‐treated cells, but not roots, infected with P. betae alone showed large differences in the total protein complement. This result is consistent with the ability of P. betae to infect roots without inducing increased transcription of infection stress‐related genes and is clearly different from a large number of other biotrophic plant/fungus interaction in which a sub‐set of defence proteins are induced even in susceptible interactions in an atempted limitation of damage. Suppression of defence responses might be the mechanism by which P. betae is able to succesfully colonise sugar beet. Beet plants with symptoms of rhizomania did not express polypeptides with mobilities characteristic of stress‐related products. However, polypeptides of mobilities characteristic of sub‐sets found within young roots were observed which is compatible with the typical symptoms of the disease.
Two Circular Single‐stranded DNAs Associated with Banana Bunchy Top Virus
Authors: Wu R. Y. 
Published: May 2008

AbstractNucleic acids extracted from partially purified banana bunchy top virus (BBTV) consisted of 20 Kb DNA, 0.9‐1.1 Kb DNA and 0.3 Kb RNA. Partially purified BBTV preparations predigested with DNase and RNase before particle disruption and nucleic acid isolation yielded only the 0.9‐1.1 Kb DNA, but no corresponding nucleic acid band was obtained in total nucleic acid isolated from healthy banana tissue. Analysis of two BBTV cDNA clones showed that clone 1 consisted of 287 nucleotides and clone 2 contained a 1.0 Kb DNA insert. Clone 1 is not part of clone 2. When two pairs of primers, each pair in opposite orientation were used to amplify BBTV DNA by PCR using the total DNA from diseased banana tissues or DNA encapsidated in BBTV particle as the template, a DNA product of 1.1 Kb was generated by both, results indicating that the BBTV DNAs are circular. Additional results suggested that BBTV contained at least two circular ssDNAs designated BBTV essDNA I (containing clone 1 nucleotide sequence) and BBTV, cssDNA II (containing clone 2 nucleotide sequence).
Production of Intraspecific Hybrids of Fusarium oxysporum f. sp. radicis‐lycoperisici and Fusarium oxysporum f. sp. lycopersici by Protoplast Fusions
Authors: Madhosingh C. 
Published: May 2008

AbstractThe fusion of protoplasts from the cycloheximide‐resistant mutant FOL(C) of Fusarium oxysporum f. sp. lycopersici (FOL) and the mycostatin‐resistant mutant FORL(M) of F. oxysporum f. sp. radicis‐lycopersici (FORL), produced hybrids which expressed significant differences from the parents in their pathogenicity and growth and in the electrophoretic separation patterns of their proteins, enzymes and isoenzymes. The results suggest a transformed genetic basis for these altered expressions and the feasibility of using protoplast fusion technology for examining the biology of pathogenicity genes and for elucidating the disease and virulence potential for new races from within hybridisable taxa of Fusarium spp. Such information would be useful for the design and development of long‐term control systems for Fusarium diseases, particularly in breeding programs for disease resistance in crops.