bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mycoparasitism of Alternaria alternata by an Additional Eight Fungi Indicating the Existence of Further Unknown Candidates for Biological Control*
Authors: Turhan Gülay 
Published: May 2008

AbstractIn studies using light and scanning electron microscopy it was clearly demonstrated that Nectria inventa, Gliocladium roseum, G. ca.tenula.tum, Clonostacbys sp., Sesquidllium sp., Verticillium nigrescens, Dicyma olivacea, Stachybotrys elegans, Myrothecium carmichaelii, M. cinctum, M. roridum, M. tongaense, M. verrucaria and Coniothyrium sporulosum are able to parasitize Alternaria alternata. With the exception of N. inventa and the five Myrothecium spp., none of the other fungi has been previously reported to be mycoparasitic on Alternaria. Moreover, there is no current information about the mycoparasitic and antibiotic activity of the genera Clonostacbys and Sesquici‐lium.The mode of parasitism was nearly the same in all of the mycoparasites. In many cases, penetration was achieved directly by the hyphal tips without the formation of appressorium like structures (ALS) and there was no evidence that the formation of ALS was a prerequisite for penetration. Dependant on the severity of infection, a gradual shrinkage, distortion and an eventual collapse of the parasitized conidia were observed. A bursting and total collapse of the spores without any penetration was detected by the antibiotic producing mycoparasites such as G. roseum, G. CAtenulatum, Clonostacbys sp., Sesquicillium sp., D. olivacea and the five Myrothecium species.In consideration of their activity, all of the tested antagonists would appear to be candidates for in vivo investigations to check their suitability as biocontrol agents.
A Carlavirus and a Rhabdovirus Infecting Lonicera X brownii cv. Dropmore Scarlet in Western Canada
Authors: Weintraub M. 
Published: May 2008

AbstractChlorotic and necrotic spots, yellow mottle, and vein banding leaf symptoms were seen on two honeysuckle vines in the Botanical Garden, University of British Columbia. Electron microscopic examination showed the presence of rhabdovirus and carlavirus particles. This is the first report of a rhabdovirus in honeysuckle. The carlavirus may be honeysuckle latent virus, although it was transmitted to only three of its nine reported herbaceous hosts, and it was not transmitted by the reported aphid vector, Hydaphis foeniculi. Both types of virus particles were seen in mesophyll, phloem parenchyma and companion cells of honeysuckle. The rhabdovirus was not transmitted to any other host and, in honeysuckle, was found only in the Spring. As its concentration declined, the number of carlavirus particles increased.
The Interaction of Either an Effective or a Defeated Major Gene with Non‐specific Resistance on Mildew Infection (Erysiphe graminis f. sp. hordei) and Yield in Mixtures of Barley
Authors: Newton A. C. , Thomas W. T. B. 
Published: May 2008

AbstractThree‐component mixtures of two barley cultivars expressing partial resistance to mildew (Erysiphe graminis f. sp.hordei) with the third component either expressing complete resistance or a defeated major gene gave more yield than the mean of their components in monoculture in a series of field trials. However, there was no reduction in mildew infection in the mixtures and even a significant increase in one trial. The potential for using partially resistant cultivars in mixtures is discussed.
Life Cycle of Mycosphaerella brassicicola (Duby) Lindau and Ascospore Production in vitro
Authors: Götz M. , Zornbach W. , Boyle C. 
Published: May 2008

AbstractThe germ‐hyphae of the M. brassicicola ascospores penetrated the host leaves (white cabbage) 10 days after inoculation during the summer at 17 °C. The penetration occurred without exception by way of the stomata. Following a period of intercellular growth which lasted up to 15 days, brownish discolourations of the host cell walls and the destruction of mesophyll cells were observed. At this stage of infection, fruit‐body primordia developed from hyaline, thick‐walled, granulated mycelium, which blackend after conglomeration due to melanine deposits. The further ascocarp development was ascolocular.Ascospore production of M. brassicicola was increased in vitro by variation of the incubation temperatures, medium‐pH and irradiation. The highest sporulation rate was obtained in cultures on vegetable juice medium adjusted to pH 6, incubated at 17 °C and subjected immediately after onset of growth to 4 h UVA radiation. The percentage of germinated ascospores (70 %) corresponded to that of the dark incubated controls. Fructification and infectivity were subject to seasonal fluctuations under growth chamber conditions.
Characteristics of a Pythium arrhenomanes with High Frequency in Barley Soils
Authors: Olsson S. , Kadir S. 
Published: May 2008

AbstractSoils from two long‐term crop rotation experiments were examined for incidence of root pathogens with a test tube method, where a great number (hundreds) of small portions (15–68g) of soil were biotested. There was a 4–5 times higher frequency of a root‐infecting Pythium sp. In barley monoculture soil when compared to crop rotation soil, where winter turnip rape was the preceding crop. In pathogenicity tests the isolated pathogen caused severe root rot on barley, wheat and rye, but did not affect growth of oats, maize, peas and winter rape. In all essential morphological characters it resembles P. arrhenomanes and we classify it as belonging to this species.
The Characterization of a Strain of Zucchini Yellow Fleck Virus Found in Southeastern France
Authors: Gilbert‐Albertini F. , Lecoq H. 
Published: May 2008

AbstractA virus was isolated from squirting cucumber (Ecballium elaterium L.) collected in France (Alpes de Haute Provence). After mechanical inoculation, eight species belonging to the Cucurbitaceae were found susceptible to this virus with systemic symptoms of mosaic, chlorotic spots, and fruit deformations. The French ZYFV (ZYFV‐Fr) isolate differed from the type strain in its ability to infect some differential host plants. Elongated flexuous particles with a modal length of 752 nm were observed by electron microscopy in leaf extracts. Cytoplasmic inclusions similar to those associated with infections by members of the potyvirus group were observed by light microscopy. The virus was found by SDS‐immunodiffusion and DAS‐ELISA to be serologically related but distinct from the type strain of zucchini yellow fleck virus from Italy (ZYFV‐lt). ZYFV has not yet been found in cultivated cucurbit plants in France; this virus appears to be restricted to squirting cucumbers in a few localities. The distribution of ZYFV in France is discussed.
Evaluation of Pathogenicity and of Cultural and Biochemical Tests for Identification of Pseudomonas syringae Pathovars syringae, morsprunorum and persicae from Fruit Trees
Authors: Burkowicz A. , Rudolph K. 
Published: May 2008

AbstractComparative studies were based on 216 isolates of the Pseudomonas syringae pathovars syringae, morsprunorum and persicae, mainly originating from fruit trees in several European countries, but also from USA, USSR, South Africa, New Zealand and Turkey. All the identified morsprunorum isolates were obtained from stonefruit trees, which were also a source of some syringae isolates.Fluorescent strains HR negative on tobacco leaves were regarded as saprophytic pseudomonads. Nearly all the HR positive but none of the HR negative isolates caused lesions on sweet cherry shoots and fruitlets. The largest lesions on sweet cherry shoots were caused by the morsprunorum isolates. Syringae strains always caused lesions on pear fruitlets, whereas the morsprunorum strains never did so. Some degree of specialization within the pathovar syringae seemed to exist.Cultural and biochemical tests well suited to differentiate the three pathovars were as follows: colour after growth in sucrose nutrient broth, liquefaction of gelatin, activity of β‐glucosidase (arbutin) and tyrosinase, use of L‐leucine, L(+)tartrate and DL‐lactate as sole carbon source, fluorescent pigment production, crystaline inclusions in the nutrient agar medium, and growth rate in 0.2% yeast extract nutrient broth. Tests for longevity on nutrient agar with 5% sucrose turned out to be fairly unreliable. A tube assay gave the most consistent results when studying utilization of organic substrates. The capability for gelatin liquefaction correlated with virulence, and mucoid isolates showed a tendency for higher aggressiveness than rough colony variants.Page of protein extracts obtained from freeze‐pressed bacterial cells revealed that the pathovars syringae and morsprunorum could be differentiated due to specific isoenzyme patterns for esterases and acid phosphatases.It was concluded that several pathogenicity, cultural and biochemical tests allowed an unequivocal differentiation of the Pseudomonas syringae pvs. syringae and morsprunorum. Some of the discriminating biochemical characters may, play a role during pathogenesis.
The Mode of Inhibition of TMV‐ and PVX‐Induced RNA‐Dependent RNA Polymerases by some Antiphytoviral Drugs
Authors: Schulze S. , Kluge S. 
Published: May 2008

AbstractSix nucleobase and nucleoside analogues (6‐aminouracil [6‐AU], 6‐aminothymin [6‐AT], 6‐fluorothymin [6‐FT], 2,4‐dioxohexahydro‐1,3,5‐triazine [DHT], 9‐(2,3‐dihydroxypropyl) adenine [DHPA] and 1‐β‐D‐ribofuranosyl‐1,2,4‐triazol‐3‐carboxamid [ribavirin]) with potential antiphytoviral activity were tested in an in vitro replication system for their effect on tobacco mosaic virus (TMV)‐and potato virus X(PVX)‐induced RNA dependent RNA polymerase. 6‐AU, 6‐AT, 6‐FT, and DHPA inhibited both polymerases which may be a target of these compounds. A Putative noncompetitive mode of inhibition is discussed. Whereas ribavirin did not affect the in vitr RNA synthesis in the established systems, the uracil‐derivative DHT inhibited only the PVX‐specific enzyme.
Increase in Cucurbit Aphid–Borne Yellows Virus Concentration by Co–infection with Sap–transmissible Viruses does not Increase its Aphid Transmissibility
Authors: Bourdin D. , Lecoq H. 
Published: May 2008

AbstractThe cucurbit aphid–borne yellows virus (CABYV) is a new tentative member of the luteovirus group which is transmitted persistently by Myzus persicae and Aphis gossypii.In muskmelon plants, mixed infection with CABYV and zucchini yellow mosaic virus (ZYMV) induced an increase in CABYV concentration estimated by double antibody sandwich–enzyme linked immunosorbent assay (DAS–ELISA), which was maximum after 3 weeks, of co–infection.Assays, conducted with other cucurbit hosts and sap–transmissible viruses showed that a similar increase occurred with most of the potyviruses tested. However, cucumber mosaic virus (CMV) and squash mosaic virus (SqMV) were inefficient for less efficient than potyviruses) in increasing CABYV concentration.Aphid transmission experiments were conducted to check whether increased virus multiplication could either enhance transmission rates or modify the mode of CABYV acquisition by aphids. However, when A. gossypii was used, no increases in CABYV, transmissibility nor in its acquisition mode were detected.
Screening for Barley Yellow Dwarf Luteovirus Resistance in Barley on the Basis of Virus Movement
Authors: Makkouk K. M. , Comeau A. , St‐Pierre C. A. 
Published: May 2008

AbstractThe movement of barley yellow dwarf luteovirus (BYDV) was evaluated in susceptible and resistant barley and bread wheat genotypes. After leaf inoculation, the virus infected the root system and the growing point of susceptible earlier than resistant, barley genotypes. No difference in virus movement occurred in resistant and susceptible wheat genotypes. It was possible to reliably differentiate susceptible from resistant genotypes when root extracts of 41 barley genotypes were tested by DAS‐ELISA 3 or 4 days after inoculation at the oneleaf stage. When barley plants inoculated at the two‐ or three‐leaf stage were assayed by tissue‐blot ELISA on nitrocellulose membrane, virus was detected in the phloem vessels of the growing points of the susceptible, but not of the resistant genotype, 4–6 days after inoculation. Our results thus suggest that screening for BYDV resistance in barley could be done quickly and cheaply especially when assays are made by the tissue‐blot test.
PVX MS, a New Strain of Potato Virus that Overcomes the Extreme Resistance Gene Rx
Authors: Tozzini A. C. , Ceriani M. F. , Cramer P. , Palva E. T. , Hopp H. E. 
Published: May 2008

AbstractA new resistance‐breaking isolate of potato virus X (PVX MS; also called PVX fcaOl) that multiplies in genotypes carrying the Rx gene was detected in Argentina. Enzyme‐linked immunosorbent assay (ELISA) assessment of PVX multiplication in mechanically inoculated micropropagated plantlets revealed that PVX MS is able to replicate in both resistant (Rx) and suceptible plantlets whereas strain PVX cp is able to replicate only in the latter. Immunoblot detection with specific monoclonal an, tibodies showed that PVX MS belongs to the serotype PVXo (common or European strain), whereas PVX HB is included in the serotype PVXA (Andean). SDS polyacrylamide gel electrophoresis followed by immunoblotting of the coat proteins of the PVXst, rains cp, cp4, HB, and MS showed that they differed in mobility with apparent mol. wts of 27.9, 28.8, 29.9, and 29.4 kDa, respectively.
Scanning Electron Microscopy of Sclerotia of Sclerotinia trifoliorum and Related Species
Authors: Arseniuk E. , Macewicz J. 
Published: May 2008

AbstractThe microanatomy of immature ‘white’, ‘slightly pigmented’ and mature, 1‐month‐old ‘black’ sclerotia of Sclerotinia trifoliorum, S. sclerotiorum, and S. minor were studied by scanning electron microscopy (SEM). A surface mycelial network was present over sclerotia at maturity. Also dried exudate on the superficial, sclerotial cells at maturity was observed. At this stage of morphogenesis an outer layer of the wall of medullary hyphae was synthesized. Two zones (i.e., rind and medulla) of hyphal tissue in sections of mature sclerotia were distinguished. The wall of rind cells was thick and one‐layered, whereas the wall of medullary hyphae was thick and bi‐layered.No lacunac (intercellular spaces) in sclerotial rind were found but the sclerotial medulla appeared to be lacunate in all three species. At the SEM level the structural organization of sclerotia of S. trifoliorum was identical to that one of sclerotia of S. sclerotiorum and S. minor. Thus, in the conducted investigation of the sclerotial stromata, a unique, structural characteristic of taxonomic importance to distinguish S. trifoliorum from the other Sclerotinia species was not found. Observations on the sclerotial morphogenesis in S. trifoliorum and the related species agree with and supplement the light and transmission electron microscope studies of other researchers.
Development and Application of Cloned DNA Probes for Clavibacter xyli subsp. xyli, the Causal Agent of Sugarcane Ratoon Stunting
Authors: Chung C. H. , Lin C. P. , Chen C. T. 
Published: May 2008

Abstract EcoRI restriction fragments of genomic DNA from Clavibacter xyli subsp. xyli (CXX) were ligated with plasmid pUC18 and cloned in Escherichia coli JM109. The cloned DNA inserts from recombinant plasmids were EcoRI‐excised and labeled with non‐radioactive digoxigenin and used as probes. Ten specific DNA probes, RSD3, 15, 30, 31, 32, 35, 37, 41, 71, and 73 were selected for disease detection and pathogen differentiation. In the specificity tests, all of the 10 CXX DNA, probes differentiated Clavibacter xyli from other bacteria specifically. Seven out of the 10 CXX probes crossreacted with C. x. subsp. cynodontis (CXC) very weakly under moderate stringency wash conditions of hybridization. In the sensitivity tests, all of the 10 DNA probes detected the homologous DNA of CXX from 0.19 to 0.75 ng. To detect various cell numbers of CXX, the DNA probes detected 104 to 105 cells effectively. In Southern hybridizations, distinctly different band patterns were shown when the probes hybridized with DNA from CXX and CXC. Among these probes, RSD3, 15, 30, 31, 35, 37, and 71, efficiently detected CXX present in the sap collected from symptomless sugarcane.
Antagonism of Chaetomium globosum, Gliocladium virens and Trichoderma viride to four soil‐borne Phytophthora species
Authors: Heller W. E. , Theiler‐Hedtrich R. 
Published: May 2008

Abstract Chaetomium globosum, Gliocladium virens and Trichoderma viride, isolated from soil samples from the Kivu‐region of Zaire, are antagonistic and mycoparasitic to four soil‐borne Phytophthora spp. Radial growth of Phytophthora cinnamomi, P. cactorum, P. fragariae or P. nicotianae mycelia was inhibited in all antagonist‐pathogen combinations; mycelial mats of Phytophthora colonies were overgrown by the antagonists and hyphae lysed. Samples of mycoparasited mycelium, plated on benlateamended PDA to inhibit the development of antagonists, showed severely reduced vitality after 77 days of dual culture.
Effects of Foliar Sprays of Phosphates on Powdery Mildew (Sphaerotheca pannosa) of Roses
Authors: Reuveni R. , Agapov V. , Reuveni M. , Raviv M. 
Published: May 2008

AbstractPowdery mildew on plants of a local clone of Rosa indica Major was significantly controlled by a single spray of 25 mM aqueous solutions of K2HPO4, KH2PO4 plus KOH, or NaHCO3, all plus Tween 20 (0.5 ml/l) or bupirimate (Nimrod) at 0.5 ml/l, which was applied 4 days before inoculation with conidial suspension of Sphaerotheca pannosa var. rosae.Disease incidence was reduced by 79, 71, 54 and 50%, as compared to controls on plants sprayed with KH2PO4 plus KOH, K2HPO4, NaHCO3 or bupirimate, respectively. Phosphates were suppressive and expressed by disappearance of 99% of the pustules and conidia, as early as 2 days after a single spray on mildewed foliage. This treatment was efficient for at least 9 days after the first application when large infected greenhouse‐grown plants were used. Re‐application of these salts on the same plants reduced the lesion area by about 90% from that recorded before the application. Phosphate and bicarbonate were more suppressive than the systemic fungicide bupirimate in the early period (up to 2 days). The suppresion effects of bicarbonate and bupirimate, however, were short‐term and not persistent, while the phosphate treatments remained significantly suppressive for up to 23 days, when the experiment was terminated. The inhibitory and suppressive effectiveness of phosphate salts is discussed in the light of their possible acceptance as ideal foliar fertilizers which should be considered for use in the field for disease control.
Use of the Polymerase Chain Reaction and Sandwich‐Hybridization for Detecting Artichoke Mottled Crinkle Tombusvirus in Artichoke
Authors: Barbarossa L. , Grieco F. , Iosco P. , Gallitelli D. 
Published: May 2008

AbstractTwo non‐radioactive methods were applied for the detection of artichoke mottled crinkle tombusvirus (AMCV) in artichoke plant sap. A sandwich hybridization method was developed using a biotinylated transcript as capture and a digoxigenin‐labelled riboprobe. The hybrid was collected onto Nylon membranes coated with streptavidin using a slot‐blot procedure. The second method was the reverse transcriptional polymerase chain reaction (RT‐PCR) carried out with three different primers obtained from widely, separated sequences of AMCV genome. In artichoke plant sap, RT‐PCR was 20‐fold more sensitive than sandwich‐hybridization and 2.5‐fold less sensitive than dor‐blot hybridization labelled with radioactive reporter groups.
Stenocarpella maydis (Berk.) Sutton Colonization of Maize Ears
Authors: Bensch M. J. 
Published: May 2008

AbstractA study was undertaken to determine the ramification of maize shank, cob and kernel tissues by Stenocarpella maydis. Trials consisting of inoculated and uninoculated treatments were planted at two localities. Shank, cob and kernels of each treatment were divided into segments and S. maydis colonization was determined. Infection of the pedicel portion of maize kernels was significantly higher than the apical portion. Preferential colonization of the embryo's of kernels was observed. Colonization of cobs occurred primarily at the attachment end of the cob, with sclerenchymatous tissues showing the greatest re‐isolation frequency. Shank segments did not show significant differences in S. maydis re‐isolation frequency, although a tendency for higher re‐isolations was observed at the stalk‐attachment end. It is concluded that S. maydis colonization occurs at the base of the ear with mycelial ramification toward the tip of the ear. The sclerenchyma and placentae were the primary colonized cob tissues. as were the embryos in the kernels.
RAPD Analysis of Pathogenic Variability in Ascochyta rabiei
Authors: Fischer C. , Porta‐Puglia A. , Barz W. 
Published: May 2008

AbstractThirty Italian isolates of the phytopathogenic fungus Ascochyta rabiei (Pass.) Labr., the causal organism of Ascochyta blight on chickpea (Cicer arietinum L.), were analysed by a random oligonucleotide primer dependent polymerase chain, reaction (PCR) technique called random amplified polymorphic DNA analysis (RAPD) using three decamer primers. In previous investigations these isolates had been differentiated in six pathogenic groups. RAPD results were summarized in an analysis using the program PAUP. With each of the primers several amplification products were observed which were common to all isolates. The results of the RAPD analyses also showed that all isolates could be identified by a unique RAPD pattern. No correlation between RAPD patterns and the division of the isolates in pathogenic groups could be established. The application of the RAPD technique for cataloguing isolates and to obtain specific genetic markers for all isolates of the species Ascochyta rabiei is discussed.
Changes in Carbohydrate, Protein and Chlorophyll Content, and Enzyme Activity During the Switch from Uredinio‐ to Teliospore Sporulation in the Bean‐rust Fungus Uromyces appendiculatus (Pers.) Link
Authors: Wagner S. , Boyle C. 
Published: May 2008

AbstractChanges in carbohydrate metabolism and senescence during the development of the bean‐rust fungus Uromyces appendiculatus (Pers.) Link were investigated. At different stages of uredinio‐ and teliospore production, samples were taken from infected and non‐infected bean leaves, beginnig with the flecking stage. The unsoluble‐carbohydrate, sucrose, glucose and fructose content, as well as fluctuations in soluble acidinvertase activity and parameters of leaf senescence were determined.While fructose remained constant without significant differences between infected leaf sections and the control, differences in the other carbohydrates and in soluble‐invertase activity could be detected. Parameters indicating leaf senescence were retarded and decreased with age, except for peroxidase activity, which was enhanced and increasd with age in infected tissue to a higher degree than in the control. The results are discussed in relation to their significance for fungal development.
Growth of Agrostis palustris in Response to Adventitious Root Infection by Curvularia lunata
Authors: Hodges C. F. , Campbell D. A. 
Published: May 2008

Abstract Curvularia lunata is reported as a minor pathogen of adventitious roots of Agrostis palustris. C. lunata isolates from roots of A. palustris were evaluated for their ability to infect adventitious roots at temperatures ranging from 23 to 48°C. All isolates of C. lunata decreased both the shoot and root growth of root‐inoculated plants during a 10‐week observation period, but failed to produce the foliar symptoms observed in the field. Shoot and root weights of inoculated, plants were 47–66% and 55–69% of their respective controls. Infected roots were light tan in colour without lesions or rot, and infections were restricted to root hairs and cortical tissue. These observations are discussed relative to the nature of the pathogenicity of C. hunata as a root pathogen and its potential function in a root disease complex.