bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Peanut Stripe Virus Isolates from Soybean in Taiwan
Authors: Vetten H. J. , Green S. K. , Lesemann D.‐E. 
Published: May 2008

AbstractPotyvirus isolates were obtained in Taiwan from soybean showing crinkle, mottle, mosaic or blistering. They were identified as peanut stripe virus (PStV) on the basis of host range, serology, molecular weight of the capsid proteins and morphology of cytoplasmic cylindrical inclusions. PStV was found to be closely related serologically to adzuki bean mosaic virus (AzMV), blackeye cowpea mosaic virus (BICMV), and the bean common mosaic virus (BCMV) strain NY 15. A clear differentiation of PStV from these related viruses was possible on the basis of the cylindrical inclusion morphology. Only the peanut isolate of PStV from the USA and the three soybean isolates of PStV from Taiwan produced pinwheels, scrolls and curved laminated aggregates whereas the other serologically related viruses produced scrolls only. Whilst the peanut isolate of PStV infected all nine peanut cvs tested, the soybean isolate PN of PStV infected two peanut cvs only. AzMV, BICMV and two strains of soybean mosaic virus did not infect any of the peanut cultivars tested. On the other hand, nineteen and three of the 27 soybean cvs were susceptible to the soybean isolate PN and the peanut isolate of PStV, respectively. The capsid proteins of the peanut and the three soybean isolates of PStV and of AzMV appeared to be proteolytically undegraded and to have nearly identical molecular weights of 35 kD. Based upon results of virus surveys in soybean plantings in Taiwan, the incidence of soybean isolates of PStV in soybean is similar to that of soybean mosaic virus, suggesting that these PStV strains might be economically significant to soybean production m Taiwan.
The Inhibition of Rust Fungus Growth in Allopurinol‐Treated Bean Plants: Indirect Evidence for the Involvement of Xanthine Oxidoreductase in the Biotrophism of Uromyces phaseoli
Authors: Montalbini P. 
Published: May 2008

AbstractAllopurinol [4‐hydroxypyrazolo(3,4‐d)pyrimidine], a specific, potent inhibitor of xanthine oxidoreductase, effective in vitro and in vivo, was applied to bean plants as soil drench at a 400 μM concentration 8–10 days before inoculation and strongly reduced the development of Uromyces phaseoli in bean leaves. Allopurinol was ineffective on uredospore germination, presumably due to the absence of any xanthine oxidoreductase activity in the extract of germinated uredospores. The concentration of allopurinol used for the treatment did not significantly influence the level of ureides in leaves mainly because low concentration of these compounds were found in leaves and also probably because allopurinol‐insensitive biosynthetic route/s of these compounds are active in bean plants. This paper examines the possibility that host xanthine oxidase is in some way involved in the biotrophic nutritional process leading to the growth of bean rust fungus.
A New Phytotoxic Activity of the Cyclic Peptides Tentoxin and Dihydrotentoxin
Authors: Liebermann B. , Kölblin R. 
Published: May 2008

AbstractExtracts of culture filtrate of the phytopathogenic fungus Alternaria alternata (Fries) Keissler cause distinct wilting of cuts of the problem weed Galium aparine L. We were able to demonstrate that the cyclic tetrapeptides tentoxin and dihydrotentoxin were reponsible for this effect. A tentoxin derivative, isolated from the culture filtrate, shows a similar, but stronger wilting activity.
Enzymes Associated with Defence against Toxic Oxygen Species in PCNB‐Tolerant and Sensitive Soil Fungi
Authors: Ephraim Cohen Prof. , Teomi Shoshana 
Published: May 2008

AbstractThe specific activities of enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPOX) and glutathione reductase (GR), which are involved in protection against toxic species of oxygen, were determined in mycelia extracts of pentachloronitrobenzene (PCNB)‐tolerant and susceptible soil fungi. The organisms assayed were the highly PCNB‐sensitive Rhizoctonia solani and Rhizopus arrhizus; Sclerotium rolfsii and Trichoderma harzianum, which are moderately susceptible to PCNB, and the fungicide‐tolerant Fusarium oxysporum f. sp. melonis and Pythium aphanidermatum. No GPOX activity was detected in the six examined fungi. Significant differences in the specific activities of the other enzyme systems among the fungi were evident. Remarkably low levels of CAT activities were measured in R. solani. Except for T. harzianum, no meaningful differences regarding SOD, CAT and GR activities with age of the fungi cultures were observed. The electrophoretic patterns of SOD and CAT displayed dissimilarities among the fungi under study. P. aphanidermatum is more polymorphic with respect to both SOD and CAT enzyme systems as compared to the other fungi. The SOD of F. oxysporum f. sp. melonis, R. arrhizus and T. harzianum is a cuprozinc enzyme, while the mangano‐SOD species was detected in S. rolfsii, R. solani and T. harzianum.
Antagonistic Activities of Trichoderma harzianum Against Pythium aphanidermatum and Pythium myriotylum on Tobacco
Authors: Devaki N. S. , Shankara Bhat S. , Bhat S. G. , Manjunatha K. R. 
Published: May 2008

Abstract Trichoderma harzianum rendered Pythium aphanidermatum and P. myriotylum non‐viable in Petri dish dual culture. The Pythium mycelia from such cultures showed natural autofluorescence in the regions of interactions, indicating their death. Non‐volatile and volatile fungicidal activities were detected in T. harzianum culture. Lytic activity of β‐(l,3)‐glucanase was detected on the cell walls of the Pythium spp. There was a significant decrease in the disease incidence when T. harzianum was incorporated into sterile soil, whereas the effect was insignificant in natural soil.
Rapid Development of Resistance of Wounds on Immature Apricot Fruit to Infection with Monilinia fructicola
Authors: Wade G. C. , Cruickshank R. H. 
Published: May 2008

AbstractCleanly cut wounds on the surface of green apricot fruit are susceptible to infection with Monilinia fructicola when freshly made, but rapidly become resistant over 6 h. This was shown to be strongly correlated with the concentration of free nutrients, particularly sugars, which remain on the surface of the wound. Nutrients were rapidly removed by diffusion and absorption by underlying living cells. This is proposed as the basis of resistance which develops rapidly as the wounds age.Structural and chemical barriers to infection, such as periderm, suberin and phenolic compounds, developed long after the wounds had become resistant.
Interspecific Hybrids between Fusarium oxysporum lycopersici and Fusarium graminearum by Mycelial Anastomoses
Authors: Madhosingh Clarence 
Published: May 2008

Abstract Fusarium oxysporum lycopersici (FOL) and F. graminearum (FG) developed mycostatin (M) and cycloheximide (C) resistant mutants (FOL[M] and FG[C]) after treatment with nitrosoguanidine. Four hybrids, obtained from hyphal anastomoses between the mutants, were isolated from medium containing both mycostatin and cycloheximide at concentrations which did not permit growth of the mutants or the original parents. Both the mutants and the interspecies hybrids (ISH) derived from them expressed significant differences in pathogenicity to tomato and wheat from that expressed by the parents FOL and FG. Protein, esterase, pectinase and polyphenoloxidase electrophoretograms displayed unique patterns for the hybrids and the mutant parents. However, these patterns did not correlate with the pathogenicity expressions obtained. The study has demonstrated interspecies hybridizations between FOL(M) and FG(C) by hyphal anastomoses. Both the processes of mutation and hybridization altered the expression of pathogenicity in tomato and wheat The significance of these observations on the origin and development of new pathogenic forms is discussed.
A Detached Cotyledon Test for the Isolation of Mutants of Pyrenopeziza brassicae Defective in Pathogenicity Determinants
Authors: Ball A. M. , Ingram D. S. , Johnstone K. 
Published: May 2008

AbstractA detached cotyledon pathogenicity test was devised for the isolation of UV‐induced mutants of the hemibiotrophie ascomycete pathogen of Brassica spp., Pyrenopeziza brassicae defective in pathogenicity determinants. At least 95 % of cotyledons of suitable susceptible cultivars of oilseed rape (Brassica napus L. ssp. oleifera cvs Shogun or Bolko) showed symptoms of disease (white spore pustules [conidiomata] on the surface of the cotyledon) within three weeks of inoculation of cotyledons with 104 conidia of P. brassicae. The test allowed rapid screening of UV‐induced mutants with a low frequency of false negatives. From 1,700 survivors of UV mutagenesis tested, 20 non‐pathogenic mutants were obtained.
Cell‐free Translation of Potyviral RNA Including Extracts from Disease Resistant Soybean
Authors: Mansky L. M. , Durand D. P. , Hill J. H. 
Published: May 2008

AbstractCell‐free translation of soybean mosaic virus (SMV), strain G2 or G7, RNAs in the presence of fractionated leaf extracts from the cultivars Davis or Williams‘82 revealed no differences that were associated with disease resistance of the cultivars to the virus strains. Extracts of leaf tissue from Davis (resistant to strain G2) and susceptible Williams‘82 were fractionated into three broad peaks. Apparent proteinase activity was detected in peak II of both soybean cultivars in the cell‐free translation of SMV‐G2 or ‐G7 RNAs. Inhibition of translation occurred in the presence of peak extracts from either of the soybean cultivars at levels of 500 μ/ml and/or 1000 μ/ml of protein. No inhibition of proteolytic processing was observed by extracts from either cultivar.
Antibacterial Activity of Tea and Coffee Wastes Against Some Plant Pathogenic Pseudomonas syringae Strains
Authors: Alström Sadhna 
Published: May 2008

Abstract In vitro and greenhouse trials were conducted to elucidate the potential use of extracts of tea and coffee wastes to control plant diseases caused by the bacterial pathogens, Pseudomonas syringae pv. pisi (race 1 and 2) and P. s. pv. phaseolicola (race 1). The antibacterial activity was measured as the diameter of the inhibition zone in agar and also by periodical viable cell counts in laboratory tests. The effect on the hypersensitive reaction and the potential for disease control after leaf infiltration and seed treatment were studied on bean plants in the greenhouse. Results showed that both the tea and coffee extracts possessed antibacterial activity against the three pathogens, but that the effects varied depending on the strain and the test method. Strong reduction of halo blight disease and improvement in plant growth was obtained in presence of the coffee extract. For the halo blight pathogen, P. s. pv. phaseolicola, there was a good correlation between the results from the viable cell count method and the greenhouse tests, but the results from the in vitro studies did not agree with those from greenhouse as regards the P. s. pv. pisi strains. It is suggested that the component(s) in tea and coffee responsible for controlling the bean pathogen may not be the same as that for the pea pathogens.
Pathogenicity to Wheat of Isolates of Pseudocercosporella herpotrichoides (Fron) Deighton from Five Graminaceous Hosts
Authors: Kayser A. , Heitefuss R. 
Published: May 2008

AbstractEleven isolates of Pseudocercosporella herpotrichoides were obtained from field material of the Gramineae Agropyron repens, Alopecurus myosuroides, Apera spica‐venti, Hordeum vulgare and Triticum aestivum. Four of these isolates belonged to the variety acuformis and 7 isolates to the variety herpotrichoides of the fungus.In a greenhouse experiment, winter wheat was inoculated with these isolates. All isolates were pathogenic on wheat. They differed in virulence, but these differences could not be related to the nature of their original hosts nor to their classification as variety acuformis or herpotrichoides.
Histopathology of Blackleg Development in Spring Rapeseed
Authors: Xi K. , Morrall R. A. A. 
Published: May 2008

AbstractHyphae of Leptosphaeria maculans were observed in all types of above‐ground tissue of two cultivars of Spring rapeseed plants exposed to natural infection. Large quantities of hyphae were distributed in the epidermis and cortex of the stem in symptomless plants at early growth stages, irrespective of resistance level of the cultivar. These results verified the extensive latent infection early in the season that had been detected by isolation in a previous study. Two types of hyphae occurred in plants: narrow hyphae (2.1 μm diam.) were usually found in symptomless plants at early growth stages, whereas thick hyphae (5.7 μm diam.) occurred in plants with symptoms as the late stages of growth. Resistance mechanisms were evidenced by the presence of heavily stained material and disintegration of the hyphae in cells of the resistant cultivar.
Purification and Some Properties of an Isolate of Beet Yellows Virus from Ukraine
Authors: Rogov V. V. , Karasev A. V. , Agranovsky A. A. 
Published: May 2008

AbstractA purification procedure, which yielded up to 15–30 mg of beet yellows virus (BYV) per 100 g of infected Tetragonia expansa leaves, has been developed. The procedure included sap clarification with Triton X‐100, and two cycles of ultracentrifugation through sucrose cushion, which contained PEG‐6000 and NaCl. A specific antiserum was prepared, and BYV infection was successfully detected by the double‐antibody sandwich (DAS) ELISA in infected sugar beet leaves and roots diluted up to 1 × 105 and 1 × 104, respectively. The virus concentration was demonstrated to decrease in infected sugar beet roots slowly during 7 months, thus allowing successful diagnosis of planting material in winter storage. BYV presence in Myzus persicae aphids was also reliably detectable using the DAS‐ELISA. In a competitive DAS‐ELISA test, the Ukraine and the British BYV isolates were found serologically indistinguishable.
A Comparison of the Disease Reactions of Stems and Detached Leaves of Soil and in vitro Grown Plants and Regenerants of Oilseed Rape to Leptosphaeria maculans and Protocols for Selection for Novel Disease Resistance
Authors: Gretenkort Marie A. , Ingram D. S. 
Published: May 2008

AbstractProtocols for selecting plant tissues of winter oilseed rape (Brassica napus subsp. oleifera) with resistance to Leptosphaeria maculans by either stem or leaf inoculation of both soil and in vitro grown plant material are described. The stem inoculation procedure gave good correlation (r = 0. 92) between the 50 day stem disease scores of eight out of nine cultivars of soil grown winter oilseed rape inoculated with isolate 41A4 of L. maculans and the N. A. B. esistance ratings or resistance data from field trials. The exception was the cultivar Liradonna. Inoculation of stems of five cultivars with isolates 41A4, 433 and 478 indicated a range of isolate virulence 478 > 41A4 > 433. This was the inverse of that observed in leaf inoculations. Application of the stem inoculation procedure to in vitro shoot cultures allowed differentiation of resistant and susceptible cultivars, including the cultivar Liradonna, after 20 days incubation at 20°C. The protocol was also applicable to plantlets regenerated from thin cell layer explants grown in vitro. Inoculations with isolate 433 allowed the differentiation of resistant, intermediately resistant and susceptible leaf material of soil grown plants, when leaf discs from young leaves were incubated on water agar supplemented with BAP (1 × 10−5 M) at 25°C for 10 days. Intermediately resistant leaves were resistant after 10 days and susceptible after 15 days of incubation. Leaves of shoot cultures grown in vitro were more susceptible than the corresponding soil grown material. However, inoculation of old leaves with isolate 41A4 (an isolate of less virulence on leaves than 433) distinguished the cultivars after 15 days of incubation. These protocols allow the accurate assessment of resistance to L. maculans at the stem or leaf level and are of use in traditional as well as in vitro selection programmes.
Incidence of White Mold and Yield of Upright Bean Grown in Different Planting Patterns
Authors: Saindon G. , Huang H. C. , Kozub G. C. , Mündel H. ‐H. , Kemp G. A. 
Published: May 2008

AbstractThe commercial dry bean (Phaseolus vulgaris L) production system in Alberta requires irrigation and the viny cultivars currently used in this production system are prone to outbreaks of white mold caused by Sclerotinia sderotiorum (Lib.) de Bary. The use of beans with an upright growth habit has potential for alleviating the disease problem, but the narrow profile of the upright beans may warrant a different planting pattern to achieve high yield. A study was undertaken to determine the effect of between‐ and within‐row spacings on the occurrence of white mold and seed yield of upright beans. An experimental navy bean composite with upright growth habit, and a susceptible control Red Mexican, UI 37, were evaluated using three between‐row (BR) and three within‐row (WR) spacings in presence or absence of white mold during a 2‐year period. The BR and WR spacings had no effect (P > 0. 05) on disease occurrence in the inoculated upright composite or in the viny control. Regardless of BR and WR spacings, the upright composite had less (P < 0. 01) disease than the control in both years. In general, large differences (P < 0. 05) were found between the upright composite and control spacing treatments in the presence or absence of white mold. BR spacing had a significant effect on seed yield, but WR spacing did not. In most cases, increasing plant density by reducing BR spacings resulted in higher seed yields. These findings suggest that producers may gain in seed yield without increasing risks for white mold occurrence by changing from viny to upright beans and planting in narrower rows.
Partial Resistance of Bell Pepper to Cucumber Mosaic Virus Movement within Plants: Field Evaluation of its Efficiency in Southern France
Authors: Nono‐Womdim R. , Palloix A. , Gébré‐Selassié K. , Marchoux G. 
Published: May 2008

AbstractThe spread of cucumber mosaic virus (CMV) was followed during three years in field plots of bell pepper varieties Yolo Wonder (susceptible) and Milord and Vania (partially resistant to CMV movement within plants). During the three test years, CMV spread was delayed 4 to 6 weeks in var. Milord and in var. Vania as compared to var. Yolo Wonder. Final CMV incidence and the apparent infection rate, the latter calculated from Van der Plank logistic analyses, were lower in var. Milord and in var. Vania than in var. Yolo Wonder. The resistance of var. Milord and var. Vania, expressed as a delay of spread and a reduced CMV incidence over the past three years, provides practical disease control.
Virus Resistance Induced with Mannan Sulphates in Hypersensitive Host Plants
Authors: Kovalenko A. G. , Grabina T. D. , Kolesnik L. V. , Didenko L. F. , Oleschenko L. T. , Olevinskaya Z. M. , Telegeeva T. A. 
Published: May 2008

AbstractMannan sulphates (MS), obtained by sulphatation of extracellular linear mannan (LM) from Rhodotorula rubra, induced resistance to tobacco mosaic virus (TMV) in hypersensitive plants, retained in isolated protoplasts. MS‐induced resistance in tobacco is accompanied by a marked increase of lytic processes in cells and a decrease of total (acidic and alkaline) protein content. In addition to this, new protein components, including PR‐proteins and antiviral substances, of the inhibitor of virus replication (IVR) type, appeared in treated plant tissues. MS‐induced resistance resembles localized resistance induced by TMV in hypersensitive tobacco plants and could serve as an experimental model for study of the latter.
The Natural Occurrence, Transmission, Properties and Possible Affinities of Cowpea Mild Mottle Virus
Authors: Jeyanandarajah Premala , Brunt Alan A. 
Published: May 2008

AbstractCowpea mild mottle virus (CMMV), although thought to be of only local importance when first found in 1973 infecting cowpeas (Vigna unguiculata) in Ghana, has since been shown to have a very extensive geographical distribution and a wide natural host range. It occurs in Africa, Asia, South America and Oceania in tomato (Lycopersicon esculenturri) and a range of leguminous crops including cowpeas, groundnuts (Arachis hypogaea, soybean (Glycine max) and French beans (Phaseolns vulgaris).The virus has physico‐chemical properties resembling those of aphid‐borne carlaviruses; it has filamentous particles ca. 650 nm long which contain a single polypeptide of 31–33 KDa and single‐stranded RNA of 2. 5 × 106. Unlike carlaviruses, however, CMMV is transmitted in a non‐persistent manner by whiteflies (Bemisia tabaci) and the particles occur in vivo in characteristic brush‐like inclusions. It is also seed‐borne in some, but not all, cultivars of cowpea and soybean, but seed‐transmission is probably dependent upon the interaction of genotype, virus strain, time of infection and environmental factors.CMMV is serologically closely related to, and thus probably synonymous with, viruses previously designated groundnut crinkle, Psophocarpus necrotic mosaic, Voandzeia mosaic and tomato pale chlorosis. It is, however, serologically unrelated to 18 recognized carlaviruses; because it is also transmitted by whiteflies and induces the formation of unusual brush‐like inclusions, it is probably best left unclassified or tentatively placed in a sub‐group of the carlavirus group until the taxonomic significance of these features has been fully evaluated.
Production of a Chlorosis‐Inducing, Host‐Specific, Low‐Molecular Weight Toxin by Isolates of Pyrenophora tritici‐repentis Cause of Tan Spot of Wheat
Authors: Brown D. A. , Hunger R. M. 
Published: May 2008

AbstractAn extraction procedure was developed to isolate toxin from cell‐free culture filtrates of Pyrenophora tritici‐repentis, cause of tan spot disease of wheat (Triticum aestivum). Designated Ptrtoxin, this low‐molecular weight toxin (MW 800–1800) induces the characteristic chlororis associated with tan spot disease when inoculated to healthy wheat leaves and differentially inhibits the elongation of wheat seedling coleoptiles. The sensitivity of seven wheat, one barley, and non‐host (corn) cultivars to Ptr‐toxin corresponds with reported field reactions to the pathogen. Seven isolates of P. triticirepentis from wheat in Oklahoma and four from smooth bromegrass Bromus inermis, an alternative host of P. tritici‐repentis), in North Dakota were evaluated for production of Ptr‐toxin in vitro.Results indicate that Ptr‐toxin may be involved in the expression of disease symptoms in tan spot of wheat, but is not the sole determinant of P. tritici‐repentis pathogenicity. Instead, toxin production may contribute to the virulence of individual isolates of the pathogen. Isolates from the alternative host, smooth bromegrass, appear at least as toxigenic as those from wheat, with the exception of one which appeared more toxigenic than four of the wheat isolates tested. Possible relationships of Ptr‐toxin to high‐molecular weight toxins reported to be produced by P. triticirepentis in vitro (Ptr‐necrosis‐toxin) are not understood.