bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Eyespot and Brown Foot Rot in Wheat Plants Inoculated with Mixtures of Pseudocercosporella herpotrichoides Types and Fusarium Species
Authors: Bateman G. L. , Munnery I. C. 
Published: May 2008

AbstractThe effects of Fusarium avenaceum, F. culmorum and Microdochium nivale on eyespot development and of types of the eyespot fungus Pseudocercosporella herpotrichoides on brown foot rot caused by the Fusarium or Microdochium spp. were investigated by sequential inoculation of wheat plants grown in pots in a controlled environment. The W‐type of the eyespot fungus induced more severe disease than the R‐type, but its symptons were suppressed to a greater extent by Fusarium spp., especially F. avenaceum. Brown foot rot symptoms were sometimes suppressed by P. herpotrichoides but were occasionally more severe when the Fusarium inoculum was applied after the P. herpotrichoides. There, sults are discussed in relation to observations of natural infections.
Study of Nutritional and Environmental Factors Affecting the Fruiting Competence of Rhizoctonia solani AG‐1
Authors: Noel T. , Axiotis S. , Labarère J. 
Published: May 2008

AbstractThe study of nutritional, physiological and physical factors affecting basidiospore development in Rhizoctonia solani evidenced the critical influence of the physiological state of the mycelium subjected to a nutritional stress for fruiting induction. Comparison of four preculture media allowed identification of the optimal nutrient status provided by glucose, yeast extract and bacto‐peptone, for subsequent basidial differentiation on a starved water agar medium. While variations of glucose and yeast extract concentrations are not determinant for basidial differentiation, the breakdown observed with a low bactopeptone concentration underscores a major role for the nitrogen content which however should be considered in a balance with the carbon source. The basidial differentiation was shown: (i) to increase as the age of the preculture used to inoculate water agar increases; (ii) to be stimulated by a dark/light regime, and (iii) to be induced and increased by a cold temperature shock (8oC) when the mycelium was derived from young precultures. The effect of the cold temperature shock indicates that the preculture conditions can induce long‐term physiological modifications in the myccelia. While the fruiting response to nutritional factors is similar whatever the strain used the response to environmental factors depends mainly on the genotype of the strains.
Micro Morphological and Chemical Investigation into the Effects of Fungal Diseases on Melissa officinals L., Mentha×Piperita L. and Salvia officinalis L.
Authors: D'Aulerio A. Zechini , Zambonelli A. , Bianchi A. , Albasini A. 
Published: May 2008

AbstractA micro‐morphological study of infected tissues and a chemical investigation into the volatile fraction of secretory tissues of healthy and infected plants were carried out. The botanic species were: Melissa officinalis L. (infected by Erysiphe galeopsidis and Septoria melissae); Salvia officinalis L. (infected by Erysiphe salviae); Mentha piperita L. (infected by Puccinia menthae).The results show that pathogenic fungal infection seriously damages the secretory tissues and stomata, causing a decrease in the amount of essential oil contained in infected plants, and modifying the composition of the plant's volatile fraction.
Studies on the Concentration of Ramularia beticola Conidia in the Air Above Sugar Beet fields in Denmark
Authors: Hestbjerg H. , Dissing H. 
Published: May 2008

AbstractConcentrations of Ramularia beticola Faut. & Lamb. conidia in the air above 3 sugar beet (Beta vulgaris L.) field were registered for a period of 41 days altogether. A significant diurnal periodicity was revealed. Two periods of 3 and 5 days, respectively, included peaks of several thousands of conidia per m3 of air. The conidial concentrations were related to temperature, relative humidity (RH) and vapour pressure of the air, and to wind speed, dew point, rainfall and hours of sunshine. A significant effect of vapour pressure was observed for 2 fields. In one field with very low conidial concentrations, vapour pressure was nearly significant. In this field only wind speed significantly influenced dispersal of conidia. In an analysis of covariance including all data, 50% of the variation was explained by field, time of day, vapour pressure and number of hours of RH above 95% in the preceding 24h.
Comparative Antagonistic Properties of Gliocladium virens and Trichoderma harzianum on Sclerotium rolfsii and Rhizoctonia solani—its Relevance to Understanding the Mechanisms of Biocontrol
Authors: Mukherjee P. K. , Mukhopadhyay A. N. , Sarmah D. K. , Shrestha S. M. 
Published: May 2008

AbstractAn isolate of Trichoderma harzianum which is less effective than G. virens in suppressing S. rolfsii and R. solani was compared with G. virens for various mechanisms of antagonism in vitro, viz., antagonism in dual culture/hyphal parasitism, parasitism of sclerotia and antibiosis. G. virens and T. harzianum were equally effective in parasitizing the hyphae of R. solani. Only T. harzianum parasitized the hyphae of S. rolfsii, and the two antagonists were comparable with respect to antibiosis on the test pathogens. However, G. virens readily parasitized the sclerotia of the test pathogens and was found to be more effective than T. harzianum in destroying the sclerotia. Under SEM, G. virens was found to colonize, penetrate, and sporulate inside the sclerotia of the test pathogens.Parasitism of sclerotia is suggested as the principal mechanism of biological control of S. rolfsii and R. solani by G. virens.
Virulence Gene Frequency Change in Erysiphe graminis f. sp. hordei Due to Selection by Non‐Corresponding Barley Mildew Resistance Genes and Hitchhiking
Authors: Huang R. , Kranz J. , Welz H. G. 
Published: May 2008

AbstractIndividual isolates (in total 4040) of Erysiphe graminis f. sp. hordei were collected between 1989 and 1991 in fields of spring barley varieties with resistance genes Mla9, Mla12 and Ml(La) in the local air spora, i.e. remote from barley fields, in Hesse, Germany. Their virulence pattern was determined on a 13‐partite differential set. In the air spora. virulence complexity (the number of virulence genes per isolate) increased by 30% (4.2 vs. 5.5) between 1989 and 1991. This was mainly due to an increase of pathotypes with virulence genes Va7, Val3, Vk and V(La). In each mildew field population, frequencies of several non‐corresponding virulence genes, e.g. V(La) on Mla9 variety, greatly increased during the period. Such change can be caused by hitchhiking selection, i.e. indirect selection resulting from asexual reproduction, and direct selection by non‐corresponding resistance genes. To separate the two effects, the aerial barley mildew population of 1991 was sampled on cv. Pallas and near‐isogenic lines of Pallas. Frequencies of non‐corresponding virulence genes as observed in samples from the near‐isogenic lines were compared to expected non‐corresponding virulence frequencies which were obtained by subdividing the sample on Pallas into 12 subsamples, comprising all isolates virulent to line 1 through 12, respectively. Among 90 resistance/virulence gene combinations selection for non‐cor‐responding virulence was significant in five cases (e.g. Va9 on Mla7 host) and against non‐corresponding virulence in nine cases (e.g. Vk on Ml(La) host). Hitchhiking selection was significant in eight cases. In 11 cases the two types of selection were significant in combination but not individually. It is suggested to monitor the stability of selection against non‐corresponding virulence genes in race surveys and utilize it in diversified barley crops such as variety mixtures in order to retard the evolution of complex races.
Faba Bean Necrotic Yellows Virus Naturally Infects Phaseolus Bean and Cowpea in the Coastal Area of Syria
Authors: Franz A. , Makkouk K. M. , Vetten H. J. 
Published: May 2008

AbstractIn an attempt to identify possible summer hosts of the faba bean necrotic yellows virus (FBNYV), a field survey was conducted in the coastal area of Syria. Using a monoclonal antibody to FBNYV in indirect ELISA, FBNYV was detected in a large number of samples from Phaseolus vulgaris L. and in a few samples from Vigna unguiculata (L.) Walp. in which it caused severe symptoms. This is the first report of natural infection of P. vulgaris and V. unguiculata with FBNYV.
Effect of Four Fungicides on Barley Net Blotch Caused by Drechslera teres
Authors: Toubia‐Rahme H. , Ali‐Haimoud D‐E. , Barrault G. , Albertini L. 
Published: May 2008

AbstractThe effect of four fungicides (benomyl, carbendazim, triadimefon and sulp hur), used in intensive barley cropping on the epidemiology of Drechslera teres f. maculata and f. teres, was investigated under a controlled environment. Two fungicides (benomyl and carbendazim) increased disease development, especially at the recommended field rate, sulphur had the same effect at lower concentrations and triadimefon promoted net blotch caused by D. teres f. teres. At the recommended field rate, carbendazim enhanced sporulation in the two pathogen forms, whereas benomyl and sulphur enhanced 14 sporulation only on the maculata form. The results showed that, under controlled conditions, most of the fungicides promotednet blotch development and that sporulation increased either as a result of the pathogen form or of the concentration of the active ingredient.
Electron Microscope Studies on Pseudomonas syringae pv. phaseolicola Isolated From Inoculated Tobacco Leaves: Changes in Flagellation, Biomass and Elemental Composition During the Hypersensitive Reaction
Authors: Hodson N. , El Masry M. H. , Sigee D. C. 
Published: May 2008

AbstractCells of Pseudomonas syringae pv. phyaseolicola were infiltrated into tobacco leaves, recovered from tissue macerates at various time intervals during the course of the hypersensitive reaction, then investigated by analytical electron microscopy to determine changes in flagellation, cell size/biomass and elemental composition.In this interaction, the rapid fall in viable count was paralleled by an immediate and progressive decrease in mean cell biomass and a delayed decrease in mean cell size. The percentage occurrence of flagella also showed a sharp fall, suggesting a marked inhibition of bacterial motility.X‐ray microanalysis of individual cells in air‐dried preparations revealed the routine presence of detectable levels of P, K and Ca throughout the time course. Although signifificant changes in mean mass fractions did occur, the elemental composition of bacterial cells remained relatively stable throughout. The maintenance of substantial levels of K during the hypersensitive reaction suggests that direct damage to bacterial cells, with resulting ion leakage, does not occur.
The Presence of the N' Gene in Nicotiana tabacum L. cv. Samsun NN
Authors: Piccirillo P. , Porrone F. 
Published: May 2008

AbstractThe N′ gene was shown to be present in the ‘Samsun NN’ line of Nicotiana tabacum by its differential response to tobacco mosaic (TMV) and tomato mosaic (ToMV) viruses in the segregating and test‐cross generations of the cross ‘Samsun NN’×‘Samsun nn’. The appearance of phenotypes reacting with local necrosis to ToMV and with systemic mosaic to TMV confirmed that the genes N and N′ are on distinct loci. An isogenic N′;N′ Samsun line was selected.
The Nucleotide Sequence of the 3′‐Terminal Region of Clover Yellow Vein Potyvirus Isolated from Calanthe sp.
Authors: Ikegami M. , Isomura Y. , Maeda T. , Inouye N. 
Published: May 2008

AbstractThe sequence of 1399 nucleotides from the 3'region of the RNA of clover yellow vein potyvirus (CIYVV‐C) isolated from Calanthe sp. was determined. The capsid protein cistron was composed of 915 nucleotides, and corresponded to a region encoding 305 amino acids with a calculated Mr of 34900: the adjacent 3'non‐coding region was 74 nucleotides long. The length of the capsid protein gene of CIYVV‐C is longer, but the 3'non‐coding region is shorter than those of other CIYVV strains (CIYVV‐30.CIYVV‐NZ and CIYVV‐B). The nucleotide sequence of the capsid protein gene and the 3'non‐coding region of CIYVV‐C RNA showed significantly higher homology with those of other CIYVV strains. These data suggest that the CIYVV‐C capsid gene arose from a frame‐shift mutation of the capsid gene of another CIYVV strain. or vice versa. CIYVV‐C has a closer affinity to other CIYVV strains and to bean yellow mosaic virus than to the other potyviruses.
Crop Growth, Disease and Yield Components of Rusted Phaseolus Beans in Ethiopia
Authors: Habtu A. , Zadoks J. C. 
Published: May 2008

AbstractCrop growth and disease epidemics in sprayed and non‐sprayed bean plots, artificially infected with rust (Uromyces appendiculatus) 3 weeks after emergence. were assessed weekly in two cultivars, at two locations for two seasons. Disease intensity was regulated by the application of a fungicide at 5 spray frequencies. Fungicide application influenced leaf area index (LAI) and reduced rust intensity. The fungicide had no significant effect on other diseases and dead leaf area. Fungicide application increased seed yield (SY) by increased numbers of pods per plant (PP). Rust severity was strongly correlated with pustule density but the overall relationships among rust assessment parameters depended on cultivar and location. Seed yield and pods per plant were highly correlated with LAI. The relationships between LAI and seeds per pod or seed weight depended on cultivar and location. Overall rust assessment parameters (rust severity and pustule density) showed close, negative relationships with seed yield. seed weight and pods per plant but not with seeds per pod. The relationships obtained in the partially resistant line 6‐R‐395 were less definite than those in the susceptible line Mexican 142. The yield parameters seed yield and pods per plant, showed strong positive relationships.
Comparative Resistance Patterns of Fludioxonil and Vinclozolin in Botryotinia fuckeliana
Authors: Hilber U. W. , Schwinn F. J. , Schüepp H. 
Published: May 2008

AbstractFludioxonil is a new non‐systemic phenylpyrrole fungicide. It is a derivative of the antibiotic pyrrolnitrin and is highly active against Ascomycetes. Basidiomycetes and Deuteromycetes. In the present study we determined the baseline sensitivity of B. fuckeliana for fludioxonil in comparison to the dicarboximide vinclozolin. Subsequently these baselines were compared with the sensitivity of dicarboximide‐resistant field isolates and with resistant laboratory strains selected on media amendedwith vinclozotin or fludioxonil, respectively. Additionally, sensitivities of genetically homogeneous ascospore progenies of sexual crosses of sensitive isolates with dicarboximide‐resistant field isolates or resistant laboratory strains were compared to, the baselines. Baseline ECst, values for the inhibition of germination ranged from 0.07 to 0.20 μg ml‐1 of vinclozolin and for mycelial growth from 0.003 to 0.016 μg ml’ of fludioxonil and from 1.7 to 2.0 μg ml‐1 of vinclozolin and for mycelial growth from 0.003 to 0.016 μg ml‐1 of fludioxonil and from 0.13 to 0.27 μg ml‐1 of vinclozolin. Sensitivity to fludioxonil of all dicarboximide‐resistant field isolates did not differ from their baseline. However, resistant laboratory strains that were selected either on media amended with fludioxonil or vinclozolin showed decreased sensitivities to both active ingredients. All sexual progenies of the crosses described above were of the parental phenotypes. We found no independent segregation of the resistance markers.
Fingerprinting of Xanthomonas campestris pv. pelargonii and Related Pathovars Using Random‐Primed PCR
Authors: Sulzinski M. A. , Moorman G. W. , Schlagnhaufer B. , Romaine C. P. 
Published: May 2008

AbstractPolymerase chain reaction (PCR) amplification of total DNA was evaluated as a method to distinguish Xanthomonas campestris pv. pelargonii from other pathovars within this species. Two sets of highly conserved enterobacterial consensus sequences were used as targets for PCR amplification: (a) enterobacterial repetitive intergenic consensus [ERIC] and (b) repetitive extragenic palindromic [REP] sequences. Nucleic acid was extracted from a total of 37 isolates of bacteria: 19 isolates ofX campestris pv. pelargonii and 18 isolates representing 10 other pathovars of X. campestris. After PCR amplification using the ERIC primer pair the DNA fingerprints of X. campestris pv, pelargonii contained two major DNA products (estimated size 500 and 740 pp) that were conserved among all 19 isolates. With the REP primer pair, the fingerprints were more complex and major DNA products ranging from ‐690 to 1650 bp were detected. Using information from both ERIC‐ and REP‐primed Imgerprints, the X. campestris pv. pelargonii fingerprints were distinguishable from the fingerprints of the other pathovars examined: pvs. citrumelo. citri, beganiae, vittans B and C. phaseoli. campestris, manihotis, juglandis, carotae and pruni.
An Electron Microscopic Study of the Infection of Spikelets of Rice by Pyricularia oryzae
Authors: Koga H. 
Published: May 2008

AbstractPenetration and colonization of spikelet tissue of a susceptible line of rice. ZTS, by Pyricularia aryzae was investigated by scanning and transmission electron microscopy. Application of a modified embodding procedure in which the period of resin infiltration was extended, gave excellent fixation of the hard spikelet tissue. Conidia germinated to produce appressoria and the epidermal cell walls were penetrated within 24 h. Hyphae had colonized sclerenchyma, parenchyma, vascular bundles, andlarge trichomes within 48 h after inoculation. Invasion of the sclerenchyma appeared to occur through pit‐pairs, where the host cell wall is thin. Conidiophores erupted directly from the epidermis, from minute protuberances and from large trichomes on the spikelet 4 days after inoculation.
Relative Wilt‐Inducing Capacity of the Culture Filtrates of Isolates of Fusarium oxysporum f.sp. radicis‐lycopersici, the Tomato Crown and Root Rot Pathogen
Authors: Madhosingh C. 
Published: May 2008

AbstractCell‐free 30‐day‐old culture filtrates of 24 isolates of Fusarium oxysporum f.sp. radicis‐lycopersici (FORL) differed considerably in their capacity to induce wilting in 28‐day‐old tomato seedings and to inhibiting the germination of tomato seeds. The wilt effects ranged from mild on leaves and lateral stems, to total collapse of the seedlings in 24 h. Wilt, leaf curl and leaf chlorosis, appearing in this sequence, were the three symptoms clicited by the culture filtrates. Boiled and non‐boiled filtrates elicited similar sympotoms. The high wilt capacity filtrates were pH 7.2; the others were generally below pH 6. The high wilt capacity filtrates showed polyphenoloxidase activity but the overall pattern of this activity did not correlate consistently with wilt capacity. The majority of the lower wilt capacity filtrates showed a net inhibition of dihydroxy‐phenylalanine (DOPA) oxidation. The study suggests that the symptoms in the tomato seedlings were elicited by toxins in the culture filtrates. Further, it appears that the differences obtained in the wilt capacity of filtrates from the isolates were due, at least in part, to inherent differences in the concentration of the toxic factors. The rapidity of the onset of wilt, the total, collaps of filtrate‐treated seedlings and the absence of fungi in wilted seedlings suggest further that the operative mechanisms are physiological and biochemical and not impairment of the seedlings’ translocation system by physical blockage with mycelia.
Agarose Medium for Germination of Oospores of Phytophthora cactorum
Authors: Shim J. O. , Yu M. Q. , Ko W. H. 
Published: May 2008

AbstractWhen oospores of Phytophthora caetorum from 30‐day‐old culture were treated with 0.25% KMnO4 for 20 min and incubated at 24°C under light for 10 days, 65–75% germinated on water agar and water agarose but only 1–21% germinated on V‐8 agar and S+L agar. Water agarose was selected because germinated oospores formed restrieted colonies on this medium that could be isolated easily. KMnO4 treatment killed sporangia, chlamydospores and mycelial fragments present in oospore suspensions. Under the above conditions, approximately 44% of oospores from 10‐day‐old culture germinated and the optimum germination rate of about 75% was obtained when oospores reached about 20 days old.
Studies on Variability of Peanut Clump Virus: Symptomatology and Serology
Authors: Manohar S. K. , Dollet M. , Dubern J. , Gargani D. 
Published: May 2008

AbstractIntensive survcys of groundnut virus diseases were carried out in Senegal from 1986 to 1990. Peanut clump virus (PCV; furovirus group) was detected in several regions in groundnuts (Arachis hypogaea), showing typical symptoms namely, small dark green leaves, short petioles and internodes, and reduced shoot size resulting in a dwarfed and bushy appearance (clumping) of the infected plants. PCV was also detected in groundnuts exhibiting variable symptoms like chlorotic leaf spots, specking, chlorotic rings or ringspots, line patterns, vein yellowing, mottle or light mosaic etc. with or without clumping. Symptoms induced by these different isolates on the test plant Chenopodium amaranticolor also showed considerable variability. Serological studies of 41 isolates of PCV (collected from Senegal, Burkina Faso, Niger and India), using seven monoclonal antibodies in Triple Antibody Sandwich ELISA (TAS‐ELISA), permitted us to distinguish five different serogroups based on their reaction profiles. However, these did not correspond to the five groups formed in an arbitrary classification based on the symptomatology of C. amaranticolor. Serogroups do not correlate with the geographic origin.
Phenylalanine Ammonia‐lyase Activity in Barley After Infection with Bipolaris sorokiniana or Treatment with its Purified Xylanase
Authors: Peltonen S. , Karjalainen R. 
Published: May 2008

AbstractPhenylalanine ammonia‐lyase (PAL) activity was determined from leaves and roots of two barley (Hordeum vulgare L.) cultivars after infection with a necrotrophic pathogen, Bipolaris sorokiniana (Sacc.) Shoem., and treatment with its purified xylanase. PAL activity increased in leaves of both cultivars 16 h after fungal inoculation but two phases, with activity peaks at 24–32 h and 40 h, were recorded only for the more resistant cultivar, Agneta. Attempts to use a PAL inhibitor, χ‐amin, ooxyacetic acid, to increase susceptibility to B. sorokiniana in barley leaves were unsuccessful. Treatments of leaves with purified xylanase resulted in more rapid (4–12 h after injection), although reduced, induction of PAL compared with fungal injection. The higher the concentration of xylanase applied the earlier the activity peaks were detected. Fungal inoculation only slightly increased PAL activity in barley roots while xylanase treatment had no effect. The basal level of PAL was however much higher in roots than in leaves. In wheat, Triticum aestivum L. resistant to B. sorokiniana, the time‐course of PAL induction after fungal infection and xylanase treatment resembled that for cv. Agneta, while in oats, Avena sativa L. (non‐host) PAL activity did not change after the treatments. The results suggest that the second phase of PAL induction, associated only with responses of barley cv. Agneta and wheat, is linked with their resistance to B. sorokiniana infection. The possible role of xylanase as an elicitor of PAL is discussed.