bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peroxidase Isoenzymes in Strawberry Roots Infected with Binucleate Rhizoctonia spp. and their Implication in Disease Resistance
Authors: Krstiĉ B. , Vico I. , Toˇiĉ M. , Stojanović G. 
Published: May 2008

AbstractInfection of strawberry plants with binucleate Rhizoctonia spp. results in an increase in peroxidase activity and the appearance of new isoforms of the enzyme. In healthy and diseased roots of two different strawberry genotypes seven peroxidase isoenzymes were found. In healthy strawberry cv. Senga Sengana, which was moderately resistant to infection, four isoenzymes (1, 2, 5, and 6) were found. Moreover the activity of these isoenzymes was increased and three new isoenzymes (3, 4, and 7) were found in infected roots. In the strawberry hybrid 3/2/86/88/R, which is very susceptible to infection, only isoenzyme 2 was present in the roots of healthy plants. Following infection, the activity of isoenzyme 2 was increased and five new isoenzymes (1, 4, 5, 6, and 7) were detectable. The results obtained indicate that strawberry resistance to binucleate Rhizoctonia may be correlated with peroxidase isoenzyme profile with particular reference to isoform 3, which is only present in infected roots of the moderately resistant cv., Senga Sengana.
Evidence for Resistance‐inducing Compounds in Conidia of Erysiphe graminis f.sp. hordei
Authors: Kristensen H. J. , Smedegaard‐Petersen V. 
Published: May 2008

AbstractPreparations of Erysiphe graminis f.sp. hordei conidia were spray‐applied to the first leaf of barley plants which were subsequently challenge inoculated with virulent powdery mildew. The powdery mildew reducing effect of the preparations was assessed by scoring the outcome of the challenge inoculation. Homogenates of ungerminated conidia, germinated conidia, and methanol‐water extracts of germinated conidia reduced the number of powdery mildew colonies. Cell wall fragments from ungerminated conidia, germinated conidia, and conidial germination fluid obtained from conidia germinated in aqueous suspension did not reduce the number of powdery mildew colonies. Microsconical analysis of the infection course following challenge inoculation indicated that the powdery mildew reducing effect is due partly to induced resistance.
Fusarium Resistance in Gladiolus: The Development of a Screening Assay
Authors: Loffler H. J. M. , Straathof Th.P. , Van Rubroek P. C. L. , Roebroeck E. J. A. 
Published: May 2008

Abstract Fusarium oxysporum f.sp. gladioli is a major pathogen of Gladiolus and resistance to this fungus is needed. A standardized screening assay to assess resistance levels in breeding selections must be developed. Corms of cultivars, ranging from susceptible to resistant, were planted either in soil infested with various inoculum levels or incubated in vitro after wound inoculation. The soilgrown corms were rated using relative length of the shoots and average disease rating. In vitro incubated corms were evaluated visually after 6 weeks. All parameters produced similar results. It was concluded that the relative length of shoots of corms after 8 weeks of growing in soil with a high inoculum level combined with the assessment of the average disease rating of the corms after either 8 or 20 weeks is an effective screening assay.
The Effect of Extracts of Some Nigerian Spices on Biodeterioration of Okro (Abelmoschus (L) Moench) by Fungi
Authors: Ejechi B. O. , Ojeata A. , Oyeleke S. B. 
Published: May 2008

AbstractAqueous and ethanol extracts of five Nigerian spices (Allium sativum, Zingiber officinale, Aframomum melegueta, Xylopia aetiopica and Monodora myristica) inhibited the growth of fungi (Botryodiplodia theobromae, Aspergillus niger, Aspergillus flavus, Mucor sp., Rhizopus stolonifer, Penicillium sp., Fusarium sp.) isolated from deteriorating okro on agar plate with an average minimum inhibitory concentration of 6.0% (v/v); a marked reduction in weight loss of the challenged extract — impregnated okro fruit was observed with A. sativum and Z. officinale. Reduction in okro carbohydrate was best inhibited by Z. officinale while X. aetiopica best limited the loss of protein. Changes in pH and titratable acidity of challenged okro was inhibited best by A. sativum. Z. officinale and A. melegueta while in all cases. M. myristica showed the least ability to reduce biodeterioration. Of the treatments applied, the combination of mild heat, and mixtures of aqueous Z. officinale and A. melequeta extracts markedly reduced biodeterioration of fresh okro as indicated by the little loss of carbohydrate (1.2%) after 3 months of storage. Spices may be economically important in the application of hurdle technology for preservation of fruits.
Immuno‐capture Polymerase Chain Reaction and Plate‐Trapped ELISA for the Detection of Apple Stem Pitting Virus
Authors: Jelkmann W. , Keim‐Konrad R. 
Published: May 2008

AbstractIsolates of apple stem pitting (ASP) and pear vein yellows (PVY) were sap transmitted from apple and pear cultivars, respectively, to Nicotiana occidentalis ssp. obliqua. Total nucleic acid extraction, including a proteinase Kdigestion of leaf homogenates prior to phenol/chloroform extraction, was of limited use for RNA template preparation. Amplification products were obtained from N. occidentalis and from apple and pear leaf tissue. Three primer combinations near the viral 3′‐ terminus resulted in amplification products of 264 bp, 610bp and 1548bp. The specificity of the products was confirmed by restriction enzyme digestion. To improve RNA template preparation and the reliability of PCR tests from woody plant tissue, a fusion protein‐specific antiserum 647 was prepared to in vitro expressed viral coat protein. This allowed us effective immunocapture RT‐PCR assays from woody tissue infected with either ASPV and PVYV. Antiserum 647 reacted in an indirect plate‐trapped ELISA with ASPV isolates from N. occidentalis, whereas two antisera prepared previously to a different coat protein fusion construct were not successful in any of the ELISA types investigated. In addition a positive test result was obtained from PVY infected pear but not from apple.
Systemic Infection of Vigna mungo Using the Cloned DNAs of the Blackgram Isolate of Mungbean Yellow Mosaic Geminivirus through Agroinoculation and Transmission of the Progeny Virus by Whiteflies
Authors: Mandal B. , Varma A. , Malathi V. G. 
Published: May 2008

AbstractAgroinoculation of blackgram (Vigna mungo) by the cloned genomic components (DNA‐A and DNA‐B) of a non‐sap transmissible isolate of mungbean yellow mosaic geminivirus (MYMV) has been demonstrated. It has been shown that MYMV has a bipartite genome. Tandem dimeric constructs of DNA‐A and DNA‐B were infectious when inoculated together and induced systemic yellow mosaic symptoms. Agroinoculation of germinated seeds of blackgram was superior to inoculation of stems of seedlings. Infection of blackgram plants was confirmed by ELISA, dot blot and Southern hybridization. Agroinfected plants contained different forms of DNA characteristic of whitefly transmitted geminiviruses. The virus from agroinfected plants was transmissible by the whitefly Bemisia tabaci.
Characteristics of Pathogenesis‐Related Proteins Induced in Phaseolus vulgaris cv. Pinto Following Viral Infection
Authors: Mohamed F. , Sehgal O. P. 
Published: May 2008

AbstractTen acidic and eight basic pathogenesis‐related (PR) proteins were induced in primary leaves of Phaseolus vulgaris cv. Pinto following infection with southern bean mosaic virus (SBMV), a virus that induces circular, brown necrotic local lesions. These PR proteins included: four, 17 kDa, serologically related, acidic proteins of unknown functions; two chitinases, one acidic (29 kDa) and one basic (32 kDa) possessing antifungal activities; and four (21 kDa, 28 kDa, 29 kDa, 36 kDa) serologically related, acidic glucanases. The production of PR proteins was minimal during the period of active SBMV multiplication; greatest increase of PR proteins occurred after SBMV had reached a maximum level. Several of these PR proteins, including the 29 kDa acidic chitinase and two acidic glucanases (21 kDa and 36 kDa) accumulated in the intercellular space fluid. Similar PR proteins were synthesized in Pinto bean primary leaves infects with any of three other viruses that formed lesions of divergent phenotypes. However, the proportion of some of the PR proteins in the various lesion‐types differed considerably. These results indicate that PR proteins play no active role in viral localization or inactivation and that their production is a metabolic adjustment to endogenous stress.
Evaluation of Spring and Winter Wheat Reaction to Fusarium culmorum and Fusarium avenaceum
Authors: Wojciechowski S. , Chelkowski J. , Ponitka A. , ŠLusarkiewicz‐Jarzina A. 
Published: May 2008

AbstractWinter (37), spring (8) wheat accessions and additionally, 7 double haploid (DH) lines were examined for susceptibility to Fusarium seedling blight after inoculation with F. culmorum and F. avenaceum. Winter accessions exhibited lower susceptibility of about 30% to both pathogens than spring cultivars. Susceptibility of winter cultivars varied from low (22%) to high (97%). Evaluation of the root was found to be more reliable than evaluation of coleoptile necrosis. F. avenaceum infected mostly root and, to a lesser extent, coleoptile and leaves, with about a three times lower disease score of coleoptile against root. F. culmorum caused a 1.5 higher disease score on root than on coleoptile. Susceptibility of DH lines was different from susceptibility of parental forms. Reaction of individual accessions to F. culmorum and F. avenaceum was different.
Survival, Germinability and Infectivity of Oospores of Peronospora viciae f.sp. fabae
Authors: van der Gaag D. J. , Frinking H. D. 
Published: May 2008

AbstractA series of experiments was conducted to germinate oospores of Peronospora viciae f.sp. fabae. With rare exceptions, dry‐stored oospores did not germinate in water nor did they infect faba bean seedlings in soil. Long‐term storage, pre‐treatment with KMnO4 or addition of nutrients to the medium did not induce germination. Survival and infectivity of dry‐stored oospores were compared to those of oospores incorporated in a silt loam and a loamy sand soil in the field during 21–22 months. Under dry conditions, the percentage of living oospores did not change as determined by the vital stain tetrazolium bromide. In soil, less than 2% of the oospores had survived after 21 months. Infectivity of oospores was determined by a bioassay 17 and 21 months after oospores had been incorporated in soil. Diseased seedlings were obtained after inoculation of faba bean seeds with oospores extracted from the soil but not with the drystored ones. Soil samples from two field plots naturally infested with oospores 2 and 3 years before the bioassay were infective. Oospores collected with diseased plant material on one of these plots and subsequently stored dry for 3 years were not infective. The results suggested that oospores need a period of natural weathering to become germinable and infective.
Witches'Broom of Sarothamnus scoparius: A New Disease Associated with a Phytoplasma Related to the Spartium Witches'Broom Agent
Authors: Marcone C. , Ragozzino A. , Seemüller E. 
Published: May 2008

AbstractIn southern and central Italy, a witches’broom and decline disease of Sarothamnus scoparius has been observed. In affected plants, phytoplasmas were detected by PCR amplification of ribosomal DNA. Restriction fragment length polymorphism analysis of PCR‐amplified DNA revealed that the diseased plants were infected by a phytoplasma that is closely related to the spartium witches’broom phytoplasma, a member of the apple proliferation group.
Investigations on Adult Plant Resistance of Barley Against Erysiphe graminis f.sp. hordei
Authors: Heitefuss R. , Ebrahim‐Nesbat F. , Ordonez M. T. , Schorn‐Kasten K. 
Published: May 2008

AbstractSpring barley cultivars and lines were tested for 3 years in field studies for adult plant resistance against Erysiphe graminis f.sp. hordei. The cultivars Osiris and Asse were selected for further detailed cytological studies and compared with the susceptible cultivar Peruvian. Under controlled greenhouse conditions, the percentage of conidia that had formed a functional haustorium and secondary hyphae (infection efficiency) was reduced in fifth leaves of the adult plant resistant cultivars. On fifth and flag leaves of adult plant resistant cultivars, papillae were formed more frequently under primary germ tubes and appressoria, and fungal penetration was prevented more often than on the susceptible cultivar Peruvian. In ultrastructural studies various types of papillae were observed, but could not be strictly correlated with penetration success or failure of the fungus.
Influence of Virus on the Chlorophyll, Carotenoid and Polyamine Contents in Grapevine Microcuttings
Authors: González E. , Mosquera M. V. , San José M. C. , Diaz T. 
Published: May 2008

AbstractWe have studied the effect of different types of virus infections on the content in chlorophylls, carotenoids and free polyamines in shoots of vine cv. Albariño cultured in vitro. The ratio of chlorophyll a/c hlorophyll b was maintained practically constant in the different cases studied. A significant increase was observed in the polyamines, especially putrescine, in shoots infected with the different types of virus, mainly in the cases of grapevine fleck disease+grapevine leafroll disease type I and grapevine stem pitting.
Leaf Disk Inoculation — a Useful Tool for Selecting Infections of Sunflower Downy Mildew at Low Inoculum Concentration, but Inappropriate to Pathotype Characterization
Authors: Spring O. , Rozynek B. , Zipper R. 
Published: May 2008

AbstractA modified technique for leaf disk inoculation of sunflower with zoosporangia of the downy mildew pathogen Plasmopara halstedii was developed. Infection with low concentrations of inoculum was obtained down to the level of single sporangia. No significant difference in the infection rate was seen between disks from cotyledons and true leaves. This makes leaf disk inoculation particularly suitable for infections at low sporangium density and for the investigation on plant tissue which cannot be infected with whole seedling inoculation. The technique seems, however, to be inappropriate for pathotype characterization using differential host lines.
A Comparison of the Resistance Against Phytophthora fragariae var. rubi, the Causal Agent of a Raspberry Root Rot
Authors: Laun N. , Zinkernagel V. 
Published: May 2008

AbstractZoospore encystment, sporulation, oospore formation and detection of Phytophthora fragariae var. rubi, the causal agent of raspberry root rot, on three Rubus genotypes with different levels of resistance were investigated. There were no qualitative or quantitative differences in encystment as determined by scanning electron and fluorescence microscopy. Susceptibility was associated with an extended period of sporulation on roots with a proportion of roots containing oospores increasing continuously until the whole root system was colonised and the fungus could be isolated from the stem bases. Quantitative resistance as found in some raspberry (Rubus idaeus) cultivars was associated with a shorter sporulation period and decreasing proportion of the roots containing oospores due to the strong regeneration of healthy roots and limited spread of the fungus in the root system. Stem bases were consequently not affected. Sporulation was very limited on a blackberry x raspberry hybrid that was almost totally resistant to root rot and sustained infections could not be found.
Immunocapture Polymerase Chain Reaction for the Detection and Characterization of Cacao Swollen Shoot Virus 1 A Isolates
Authors: Hoffmann K. , Sackey S. T. , Maiss E. , Adomako D. , Vetten H. J. 
Published: May 2008

AbstractOligonucleotides derived from the flanking regions of the putative coat protein gene of the cacao swollen shoot badnavirus isolate I A (CSSV‐1 A) were able to prime the synthesis of specific products directly from extracts from CSSV‐IA‐infected leaves by immunocapture polymerase chain reaction (IC‐PCR), following trapping of virions with polyclonal antibodies to CSSV‐1 A. CSSV isolates serologically distinct from CSSV‐I A were not detected by IC‐PCR when the CSSV‐I A‐derived primers were used following trapping with homologous antisera. IC‐PCR was at least 100‐fold more sensitive than double antibody sandwich (DAS)‐ELISA in comparative tests on samples from greenhouse‐grown cacao plants. The superior sensitivity of IC‐PCR over DAS‐ELISA was confirmed in attempts to detect and identify CSSV‐I A isolates in field samples and permitted detection of CSSV‐I A isolates even in symptomless leaves from plants showing stem swelling only. The IC‐PCR products obtained from four randomly selected field samples were sequenced and shown to contain a region of the CSSV‐I A genome where ORF X overlaps ORF 3. Analysis of the partial amino acid sequences deduced from ORF 3 and ORF X of the four field isolates revealed a considerable variation in these CSSV‐I A gene products.
Shoot‐feeding Aphids Promote Development of Gremmeniella abietina, the Fungal Pathogen Causing Scleroderris Canker Disease in Conifers
Authors: Virtanen T. , Ranta H. , Neuvonen S. 
Published: May 2008

AbstractWe tested experimentally whether shoot feeding aphids Cinara pinea (Mordv.) can promote the development of Gremmeniella abietina (Lagerb.) Morelet, a fungus which causes Scleroderris canker disease in conifers. Pine seedlings were infested with aphids at two different times, and subsequently inoculated with conidia of G. abietina at two different times. The degree of infestation was classified into three groups based on the number of aphids/seedling: none, one (low level), and three (high level). Because of parthenogenetic reproduction, the number of aphids increased during the summer, so we also used aphid numbers to explain the development of the symptoms. Necrosis caused by G. abietina was more prevalent in seedlings infested by aphids in June, and inoculated with fungus in July. Expressed as percents of the total length of the shoots, the necrosis had advanced 50%, 70%, and 95% with no, low, and high aphid levels, respectively. Canker formation was significantly greater when G. abietina conidia were inoculated in July, compared to August. In August, there were no statistically significant differences in the intensity of disease between aphid infestation levels, but the mean number of aphids was related to disease intensity. In the spring following infection, seedlings with aphids had more dead and fewer healthy terminal buds compared to seedlings without aphids.
Polyacrylamide Gel Electrophoresis (PAGE) and Densitometric Measurement of Enzyme Activity of the Pea Root Pathogen Aphanomyces euteiches in Pea Roots
Authors: Kiøller R. , Rosendahl S. 
Published: May 2008

AbstractA new method to measure enzyme activity of the fungal root pathogen Aphanomyces euteiches in pea roots is described. The specific enzymes of the fungus and the host were separated by polyacrylamide gel electrophoresis (PAGE) and the activity of fungal Glucose‐6‐phosphate dehydrogenase and Phosphoglucomutase were quantified by densitometry. Fungal activity could be correlated to the percentage infected root length and to the disease symptoms of the plants. The activity of A. euteiches was studied in a time course experiment with increasing levels of zoospore inoculum. The results indicated that an increase in inoculum level resulted in a faster disease development in the plants. The relation between fungal enzyme activity and infection level is discussed.
Occurrence of Fusarium oxysporum f. sp. cumini in the Island of Chios, Greece
Authors: Pappas A. C. , Elena K. 
Published: May 2008

AbstractA severe disease of cumin causing pre‐mature plant death was observed in the island of Chios, Greece. Disease symptoms included sudden red‐brown shrivelling of the foliage, growth retardation and pre‐harvest plant death. From plants showing early disease symptoms Fusarium oxysporum (F.o.) was consistently isolated. In artificial inoculations, representative isolates from this fungus species were found to be pathogenic on cumin, confirming the belonging to the f. sp. cumini. This is the first report of F.o. f.sp. cumini in Greece.
A Serious Disease of Groundnut Caused by Cowpea Mild Mottle Virus in the Sudan
Authors: El‐Hassan S. M. , Naidu R. A. , Ahmed A. H. , Murant A. F. 
Published: May 2008

AbstractA serious disease of groundnut (Arachis hypogaea L.) characterized by stunting of plants, downward rolling, mottling, general chlorosis and reduced size of the leaflets was observed in the Sudan. Surveys conducted from 1992 to 1994 showed that this disease was restricted to irrigated groundnut crops grown between the two Niles. The virus had slightly flexuous filamentous particles (626 nm long) and was transmitted by whiteflies. It was identified serologically as cowpea mild mottle virus (CPMMV). This appears to be the first record of natural occurrence of CPMMV on groundnut in the Sudan and the first evidence that it causes a disease of major economic importance.
Medium‐ and Light‐dependence of Growth and Conidiomata Production in Phaeocytosporella zeae Pathogenic to Maize
Authors: Lević J. , Petrović T. 
Published: May 2008

AbstractCulture appearance, mycelium growth and pycnidial conidiomata formation in Phaeocytosporella zeae cultivated on potato dextrose agar (PDA), Leonian agar and carnation leaf agar (CLA) during permanent dark (25 C) or a 12‐h photoperiod (24/18°C) are described. Different media and light conditions significantly affected fungus growth and the occurrence of conidiomata.Dark conditions favoured more mycelium growth of the fungus than alternating light and dark. Moreover, fungus growth was more rapid on PDA and CLA media than on Leonian agar. Carnation leaf agar and a 12‐h photoperiod provided excellent conditions for the promotion of rapid conidiomata formation in a number of P. zeae isolates.
Genetic Fingerprinting of Pseudomonas syringae Pathovars Using ERIC‐, REP‐, and IS50‐PCR
Authors: Weingart H. , Völksch B. 
Published: May 2008

AbstractPCR fingerprinting using primers corresponding to repetitive (ERIC and REP) and insertion sequences (IS50) was investigated as a method to distinguish the pathovars of Pseudomonas syringae. After amplification of total DNA with the ERIC‐, REP‐, and IS50‐PCR followed by agarose gel electrophoresis. most of the tested pathovars showed specific patterns of PCR products. The differences between the fingerprints among strains within a pathovar were small, with the exception of pathovars syringae, aptata, and atrofaciens. The fingerprints of the related pathovars savastanoi, phaseolicola, glycinea, morsprunorum, tabaci, lachrymans, and mori generated with the ERIC‐ and REP‐primers were found to be very similar, showing the potential of this technique for taxonomical studies. In contrast, the IS50‐PCR fingerprints of these pathovars were clearly distinguishable. The fingerprint patterns of a strain were highly reproducible with all three tested primer sets, also when whole cells were added to the reaction mixture. Thus, the PCR technique with the ERIC‐, REP‐, and IS50‐primers is a rapid, simple, reproducible, and low cost method to identify and classify strains of the Pseudomonas syringae pathovars.