bluuebunny/crossref_metadata_2025_split huggingface dataset:
Further Evidence for the Inclusion of Barley Mild Mosaic Virus (BaMMV) in the Baymovirus Group
Authors: Andersen J. F. , Davies J. W. , Coutts R. H. A. 
Published: May 2008

AbstractBarley mild mosaic virus (BaMMV) has been purified by a new procedure and some molecular characteristics of the RNA studied. Results summarized in this paper suggest that, although BaMMV and barley yellow mosaic virus are different viruses, they share many features in common. BaMMV should, therefore, be classified in the baymovirus group of the Potyviridae.
Partial Characterization of Nasturtium Mosaic Potyvirus
Authors: Da Graça J. V. , Budnik K. 
Published: May 2008

AbstractNasturtium mosaic virus, hitherto considered to be a carlavirus, was shown to be a member of the potyvirus group by its morphology, capsid protein size, positive reaction with potyvirus group antiserum and the presence in its host of cytoplasmic inclusions (“pinwheels”). It is serologically unrelated to five other well characterized potyviruses.
Detection of Three Plant Viruses by Dot‐Blot and Tissue‐Blot Immunoassays Using Chemiluminescent and Chromogenic Substrates1
Authors: Makkouk K. M. , Hsu H. T. , Kumari S. G. 
Published: May 2008

AbstractDetection of bean yellow mosaic virus (BYMV), impatiens necrotic spot virus (INSV) and lily symptomless virus (LSV) by dot‐blot and tissue‐blot immunoenzymatic assay was compared by using either chromogenic or chemiluminescent substrates. Testing was conducted on infected‐leaf extracts and on purified virus preparations. Both types of substrates gave comparable results with leaf extracts. However, with purified virus, the use of chemiluminescent substrates led to a more sensitive detection of the three viruses.
Evaluation of Streptomyces for Biocontrol of Bipolaris sorokiniana and Sclerotinia homoeocarpa on the Phylloplane of Poa pratensis1
Authors: Hodges Clinton F. , Campbell Douglas A. , Christians Nick 
Published: May 2008

AbstractSeveral species of Streptomyces were evaluated for their ability to control Sclerotinia homoeocarpa (dollar spot) and Bipolaris sorokiniana (leaf spot) on the phylloplane of Poa pratensis (Kentucky bluegrass). Species evaluated included S. diastaticus (S32), S. galbus (S35), and S. hygroscopicus (isolates S13, S28). All evaluations were conducted on the upper epidermis of intact attached leaves of P. pratensis, and antagonism was measured as the ability of Streptomyces isolates to prevent chlorophyll loss from leaves inoculated with B. sorokiniana or S. homoeocarpa during pathogenesis. Only S. hygroscopicus (S13) effectively prevented infection and subsequent chlorophyll loss from leaves inoculated with B. sorokiniana or S. homoeocarpa. Isolate S28 of S. hygroscopicus showed erratic antagonism of both pathogens, depending upon how the isolate was prepared for use. Streptomyces diastaticus and S. galbus were antagonistic to S. homoeocarpa only in whole culture form.
Interaction between Pseudomonas syringae pv. Pisi and Isolated Pea Mesophyll Protoplasts
Authors: Akpa A. D. , Archer S. A. 
Published: May 2008

AbstractThe interaction between five races of Pseudomonas syringae pv. pisi (PSP) and isolated mesophyll protoplasts obtained from five pea cultivars was studied. There was no trend in the attachment of bacterial cells to surfaces of compatible and incompatible host protoplasts. The viability of protoplasts from compatible and incompatible host‐pathogen interactions did not differ significantly; however, changes in the viability of cultivar Kelvedon Wonder protoplasts, compatible with all five races, was relatively more stable following inoculation with bacteria than those of cultivar Fortune, incompatible with all of the five races. Protoplast cell wall regeneration did not take place until 24–48 h after isolation. It is concluded that the use of pea protoplasts as a model system for studying the pea‐PSP interaction appears to have considerable potential for the future, but more basic research is required.
Fungi in Living Symptomless Needles of Pinus sylvestris with Respect to Some Observed Disease Processes
Authors: KoWalski Tadeusz 
Published: May 2008

AbstractThe mycoflora in living symptomless needles of Pinus sylvestris was investigated in three 5–8 year‐old plantations in Southern Poland from 1987 to 1990. The needles from trees with symptoms of the autumn needle cast and from trees without such symptoms were treated separately. In total 960 of the current year and 720 of the previous year needles were collected. Fungi were isolated from 80.1 % of needles and 3671 cultures belonging to 86 fungal taxa were obtained. Seven species of fungi showed the rate of infection above 5%: Anthostomella formosa, Lophodermium seditiosum, Cydaneusma minus, Cenangium ferruginosum, Lophodermium pinastri, Sclerophoma pythiophila and Anthostomella pedemontana. The frequency of infection of needles by these species depended on needle age, season of the year, calendar year and site. The spread of fungi in needles was not too high. They were found in 35.8 % of needle sections (isolations were made from 10,080 sections). The needle base, middle and top were infected with more or less similar frequency, but the differences were considerable for the individual fungal species. Anthostomella formosa and A. pedemontana generally occurred slightly more frequently on needles of trees without symptoms of the autumn needle cast, while the other four common species (Cenangium ferruginosum, Cyclaneusma minus, Lophodermium pinastri, Lophodermium seditiosum) generally occurred more frequently on needles of trees showing such symptoms. There were considerable differences in this respect among plantations investigated.
Reduced Development of Grey Mould (Botrytis cinerea) in Bean and Tomato Plants by Calcium Nutrition
Authors: Elad Y. , Volpin Hanne 
Published: May 2008

AbstractFertilization of bean plants grown in perlite with 1 and 3 mM CaCl2 or Ca(NO3)2 reduced severity of grey mould as compared with control plants or plants fertilized with 5 mM of the compounds. Fertilization with Ca(NO3)2 reduced severity leaf grey mould and fruit ghost spots of tomato plants grown in perlite by 70 and 45%, respectively. The rate of decrease varied with the position of the fruits on the plants. Leaves from plants treated with calcium or otherwise [KNO3, (NH4)2SO4] produced less ethylene than leaves of nontreated plants. Rate of growth of B. cinerea was lower on growth medium prepared from washings from leaves of calcium fertilized plants than from leaves from other treatments. The fertilizer combination Ca(H2PO4)2+ CaSO4 (1 and 3 g/kg soil) applied once to tomato plants grown in soil reduced severity of leaf grey mould by 80 % (significant at P = 0.05) but 1–3 g CaSO4/kg soil only tended to reduce disease severity (30–40 %, not significant) as compared with the control. The compounds CaCl2 and Ca(NO3)2 increased significantly (P = 0.05) the growth of B. cinerea on synthetic medium when applied at rates of 1 0–10.0 mM whereas reduction of growth was observed with 0.1 mM of the compounds and of CaSO4.
Stress Proteins and Isozymology of Acid Phosphatase, Esterase, and Peroxidase in Phaseolus vulgaris Following Peanut Mottle Virus Infection
Authors: Wagih E. E. 
Published: May 2008

AbstractThe present work was undertaken to study soluble protein changes and enzyme alterations in “Topcrop” bean (Phaseolus vulgaris L.) primary leaves following inoculation with peanut mottle virus (PMV) in an attempt to elucidate the biochemical basis of the hypersensitive reaction in this host virus combination. Using the discontinuous polyacrylamide gel electrophoresis (disc‐PAGE) technique, at least four apparently “novel” protein bands at Rf values of 0.80, 0.77, 0.74 and 0.68 were observed in infected tissue. The band at Rf 0.76 seems to be injury related and is shown here to be an isozyme of acid phosphatase. It is believed that these proteins are neither the cause nor the product of necrosis and may thus play a role in the active defense mechanism of the plant. In this virus host combination it was found that heating soluble protein fractions at 55 °C for 10 min before electrophoresis dramatically reduced the background and improved resolution on gels. While the biological function(s) of these proteins needs further investigations it is almost certain that none of them is an isozyme of alkaline phosphatase, acid phosphatase, esterase, or peroxidase. Zymogram analysis has additionally revealed the absence of alkaline phosphatase activity in untreated, abraded and PMV‐infected primary leaves and no qualitative or quantitative changes in esterase isozymes have been observed in primary leaf tissues following abrasion or PMV–infection. By contrast, qualitative alterations in acid phosphatase after PMV‐infection and both qualitative and quantitative changes in peroxidase after mechanical abrasion and PMV‐infection have also been demonstrated.
Some Properties of Singapore Ageratum Yellow Vein Virus (SAYVV)
Authors: Tan H. N. P. , Wong S. M. 
Published: May 2008

AbstractA whitefly‐transmitted geminivirus was found in a local weed, Ageratum conyzoides L. It caused leaf vein yellowing which developed into a bright yellow mosaic at an advanced stage of infection. The virus could not be transmitted by inoculation with sap, by seed or by dodder. By whitefly transmission, the virus was transmitted to seven species belonging to the families of Compositae, Oxalidaceae and Solanaceae. Generally, symptoms observed were either vein yellowing or leaf curling. Cytopathological studies showed the reduction of chromatin to a few periphery clumps within infected nuclei and the appearance of electron‐dense fibrillar rings within the sieve elements. Both large and small fibrillar rings which are considered as diagnostic features for geminivirus infection were observed.
Identification of Intersterility Groups of Heterobasidion annosum by Restriction Analysis of PCR Products
Authors: Karjalainen R. , Fabritius A. ‐L. 
Published: May 2008

AbstractPolymerase chain reaction (PCR) was used to amplify ribosomal RNA (rRNA) genes of two isolates belonging to different intersterility groups of Heterobasidion annosum. Amplification of nuclear small rRNA or small mitochondrial rRNA yielded products of similar size in both intersterility groups. Digestion of PCR products with restriction enzymes did not reveal any differences between groups. Amplification of an internal transcribed spacer (ITS) region yielded an 0.3 kb product in both isolates. Digestion of this product with Hha I restriction enzyme revealed an intersterility specific banding pattern. These results indicate that PCR has a considerable potential for the diagnosis and characterization of fungal pathogens which are difficult to identify in conventional ways.
Studies on Particle Components of Cacao Swollen Shoot Virus
Authors: Uhde Christiane , Vetten H. J. , Maiss E. , Adomako D. , Paul H. L. 
Published: May 2008

AbstractVirions of the cacao swollen shoot virus (CSSV) strain 1A were purified and used for studies of its particle components. CSSV virions had a buoyant density of 1.365 g/cm3 in buffered CsCl. Following SDS polyacrylamide gel electrophoresis (PAGE), CSSV‐specific proteins were identified in electroblot immunoassays (EBIA) with cross‐absorbed polyclonal antibodies and especially well with monoclonal antibodies (MABs) to CSSV‐1A. Based upon EBIA experiments with a selected MAB, CSSV virions appeared to have one capsid protein species with a relative molecular mass (M), of about 43 kd that was shown to be not glycosylated. However, this protein is sensitive to proteolytic degradation as degradation products ranging from 37 to 33 kd were found in addition to the 43 kd protein. Studies on the viral genome of CSSV revealed that CSSV virions contain a DNA of about 7. 5 kbp. Nucleic acid probes obtained by cloning parts of the viral genome yielded specific hybridization reactions with extracts and preparations from plants infected with strain 1A of CSSV but not with those from non‐inoculated plants. One clone of 738 bp was sequenced and shown to contain a motif similar to the putative RNA binding domain of pararetroviruses. Based upon particle morphology and properties of the virion components, CSSV can be grouped with other nonenveloped bacilliform viruses for which the name badnaviruses has been proposed.
Monoclonal Antibodies Specific for Xanthomonas campestris Bacteria Pathogenic on Wheat and other Small Grains, in Comparison with Polyclonal Antisera
Authors: Bragard G. , Verhoyen M. 
Published: May 2008

Abstract4 hybridoma cell lines (named F1‐AA9‐D9, F1‐AB3‐B6, F1‐BC7‐C1 and F2‐CA7‐F11) secreting monoclonal antibodies to Xanthomonas campestris pv. undulosa were produced by fusing splenocytes from immunized Lou rats with IR983F myeloma cells. Whole cells were used both as immunogen and as antigen in ELISA and indirect immunofluorescence tests.The monoclonal antibodies produced reacted positively with X. c. pv. undulosa (38 strains), pv. translucens (3), pv. hordei (3), pv. cerealis (2) and pv. secalis (1).Strains from other pathovars (X. c. pv. arrhenatheri, pv. graminis, pv. manihotis, pv. oryzicola, pv. poae and pv. pruni) and from other species (X axonopodis, X. ampelina) and genus (Pseudomonas, Erwinia, Clavibacter, wheat saprophytic strains) gave a negative reaction. In comparison, seven polyclonal rabbit antisera showed to be less specific: they reacted with unrelated X. campestris pathovars as well as with Pseudomonas strains. Nevertheless, the use of phenol‐treated cells in Ouchterlony double immunodiffusion could reduce the effect of cross‐reaction for antisera.The detection of X. c. pv. undulosa by indirect immunofluorescence on infected wheat seed lots has already been applied with success.
Differentiation and Diagnosis of Pseudocercosporella herpotrichoides (Fron) Deighton with Genomic DNA Probes
Authors: Frei U. , Wenzel G. 
Published: May 2008

AbstractRepetitive genomic clones were used to differentiate between varieties within the species Pseudocercosporella herpotrichoides. From 21 clones tested 13 revealed restriction fragment length polymorphisms among isolates. Cluster analysis was performed based on these data. Differentiation of isolates according to growth speed corresponds better to genetic information than differentiation on the basis of spore morphology. Pathogen‐specific probes can be used in early diagnosis of the pathogen in infected plant material. Furthermore polymorphic pathogen‐specific probes allow varieties to be differentiated directly in infected plant material without isolation and culture of the fungus.
Production and Fungitoxicity of the Terpenoid Phytoalexins in Cotton Inoculated with Fusarium oxysporum f. sp. vasinfectum
Authors: Zhang Jiuxu , Mace M. E. , Stipanovic R. D. , Bell A. A. 
Published: May 2008

AbstractFour terpenoid phytoalexins, desoxyhemigossypol (dHG), hemigossypol (HG), desoxyhemigossypol‐ 6‐methyl ether (dMHG) and hemigossypol‐6‐methyl ether (MHG), were identified with HPLC analysis of extracts from the moderately Fusarium wilt resistant cotton var. TAMCOT CAMD‐E (Gossypium hirsutum) inoculated with Fusarium oxysporum f. sp. vasinfectum (F. o. v.). Concentrations of dHG, HG, dMHG and MG in stem steles at 10 days after inoculation were 45.1, 175. 0, 38. 3 and 1. 6 (g g–1 fresh tissue, respectively. The bioassays demonstrated that all four phytoalexins were toxic to F. o. v. The ED50's of dHG, dMHG and HG were calculated as 8. 8, 13. 4 and 29. 3 (g ml−1, respectively. The very low solubility of MHG in the standard assay medium prevented the determination of its ED50 value. Only dHG is water soluble at levels that appear necessary to act as an effective phytoalexin. At 30 μg ml−1, dHG kills all conidia and mycelia of F. o. v. Viable propagules of F. o. v. were recovered from the steles of inoculated plants 10 days after inoculation; however, the pathogen was restricted to a zone 15 cm above the hypocotyl inoculation site. Thus, the fungistatic action of dHG appears to contribute to the resistance of cotton to Fusarium wilt by preventing the systemic distribution of F. o. v. propagules.
Histopathological Studies of Resistance of Sunflower (Helianthus annuus L.) to Downy Mildew (Plasmopara halstedii)
Authors: Mouzeyar Saïd , De Labrouhe Denis Tourvieille , Vear Felicity 
Published: May 2008

AbstractHistopathological studies of the infection of sunflower seedlings by downy mildew (Plasmopara halstedii) have shown that penetration of roots and the lower part of the hypocotyl occurs for both compatible combinations (suseptibility) and incompatible combinations (resistance). After penetrating susceptible genotypes, the parasite develops intercellular hyphae and intracellular haustoria, leading to systemic invasion. In contrast, in resistant plants, as soon as colonization develops, hypersensitive‐like reactions occur in the parenchyma, with the appearance of necrotic zones surrounded by dividing cells. Growth of the parasite is strongly inhibited and most hyphae are blocked before they reach the cotyledonary node.
Mitochondrial and Nuclear DNA Restriction Enzyme Analysis of the Closely Related Phytophthora Species P. infestans, P. mirabilis, and P. phaseoli
Authors: Möller E. M. , De Cock A. W. A. M. , Prell H. H. 
Published: May 2008

AbstractTo determine relatedness of the phytopathogenic fungi Phytophthora infestans, P. mirabilis, and P. phaseoli restriction fragment patterns of mitochondrial DNAs of several isolates and hybridization patterns of nuclear DNAs after Southern hybridization with a specific homologous probe were analyzed.All but two isolates of P. infestans and P. mirabilis show very similar restriction fragment patterns differing only in the length of one fragment due to small insertion/deletion(s). Two isolates of P. mirabilis have one additional site for Scr FI. On the contrary at least six sites differ in P. phaseoli when compared to the other two species. The mitochondrial genome of P. phaseoli is considerably smaller (approx. 6 kbp) than those of P. infestans and P. mirabilis.A cloned 430 bp multicopy DNA sequence, derived from P. infestans, hybridized specifically with P. infestans, P. mirabilis, and P. phaseoli out of 61 species of Peronosporales (Phytophthora, Halophytophthora, Pythium, Albugo, Bremia, Peronospora, Plasmopara) tested and therefore has potential as a diagnostic probe. Restriction patterns revealed by this probe are invariant intraspecifi‐cally but differ between the three species.We consider P. mirabilis a forma specialis of P. infestans because of the very high similarly in its mitochondrial DNA restriction patterns.
Effects of Temperature on BYDV Concentration in Oat Plants and Virus Purification Efficiency, and Detection of a Putative Associated Satellite Virus
Authors: Forde S. M. D. 
Published: May 2008

AbstractRPV and MAV‐like serotypes of barley yellow dwarf virus (BYDV), designated R‐568 and F, were found during sucrose density gradient centrifugation to suspend at 10 °C and 4 °C but to totally sediment at 15 °C and 12 °C, respectively. These properties were used to purify these serotypes, and antisera were then prepared.Partially purified IgG from antiserum was used in immunosorbent electron microscopy (ISEM) and in enzyme‐labelled immunosorbent (ELISA) tests to detect BYDV RPV‐like serotypes. Using anti‐BYDV R‐568 polyclonal antiserum and the BYDV R‐568 serotype in ISEM tests, isometric virus particles of two sizes were trapped: the 28 nm particles of BYDV R‐568, and others 17 nm in diameter which may be those of a satellite virus.The effects of temperatures on virus concentrations in oat plants infected with BYDV serotypes F and R‐568 were investigated. BYDV F and R‐568 concentrations in the roots and shoots were sensitive to changes in temperature between 10 °C and 25 °C. The concentrations of both viruses in the roots and shoots of infected plants could be manipulated by varying the temperature at which plants were grown. The ELISA absorbance values related to detection of F MAV‐like serotypes were higher in roots and shoots of oats grown at 10 °C than for oats grown at 25 °C. Conversely, cool temperatures reduced the absorbance values for R‐568 RPV‐like serotype in the roots, but less significantly in the shoots.
Hydrolytic Enzymes of Ungerminated and Germinated Conidia of Erysiphe graminis DC f. sp. hordei Marchal
Authors: Frič Fridrich , Wolf Gerhard 
Published: May 2008

Activities of hydrolytic enzymes (esterase, lipase, phosphatase, protease, 1,3‐β‐glucanase, chitinase and amylase) were demonstrated in washings and extracts of ungerminated and germinated conidia of Erysiphe graminis f. sp. hordei, Marchal. No cellulase and only very little xylanase activity was detected. Considerable amounts, 65% of total conidia proteins can be extracted by shaking the conidia when the extraction medium contained non‐ionic detergent only. Different extraction procedures were used to determine enzyme distribution between exo‐ and endoconidial compartments and to evaluate the enzyme extraction efficiency from conidia.The possible physiological roles of the hydrolytic enzymes in the ungerminated as well as in the germinated conidia were discussed.
Severe Outbreak of Pseudomonas syringae pv. avellanae on Hazelnut in Italy
Authors: Scortichini M. , Troplano F. G. 
Published: May 2008

Pseudomonas syringae pv. avellanae, the causal agent of bacterial canker of hazelnut, has been isolated for the first time in Italy. Biochemical tests were consistant with the type‐strain of the microorganism and whole‐cell protein profiles of the studied isolates were similar to those of the type‐strain. When artifically inoculated, either in summer or in autumn, the isolates incited the same symptoms as those observed in the field.The main symptoms are the failure of the buds to swell or their withering after breaking in spring; the chlorosis of the foliage and rapid withering of the leaves that remain attached on the twigs during summer; dark brown discolouration of the bark and cambium, necrosis in the primary roots and the final dieback of the plant. The pathogen killed more than 1,800 adult hazelnut plants in one orchard within a period of five years. The main differences of the symptomatology between bacterial canker and bacterial blight of hazelnut, caused by Xanthomonas campestris pv. corylina, and the “seccume” of the hazelnut are briefly discussed.