bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Pyroquilon, an Inhibitor of Melanin Synthesis, on Sporulation and Secondary Infection of Magnaporthe grisea
Authors: Uehara T. , Arase S. , Honda Y. , Nozu M. , Tswimoto K. 
Published: May 2008

AbstractThe effect of pyroquilon. an inhibitor of meianin synthesis. on the sporulation and secondary infection of Magnaporthe grisea spores was investigated. Spore formation of M. grisea was significantly inhibited on the pyroquilon‐containing medium. but mycelial growth was not impaired. Moreover, although the colour of the spore suspension obtained from control medium without pyroquilon was black, the suspension prepared from spores which had grown on the pyroquilon‐containing medium was red‐brown. The cell walls of the spores consisted of two layers. the outer of which was highly electron‐dense and saw‐like in cross section, regardless of treatment. Both the outer and the inner layers of the cell walls of spores which had grown on pyroquilon‐containing medium were thin compared with those of control spores. When M. grisea spores which had formed on the pyroquilon‐containing medium were inoculated onto rice leaf sheaths, red brown appressoria were formed. Compared with the control, appressorial penetration and hyphal growth in the host cells were inhibited. The inhibitory effect pyroquilon exerted upon the infection behavior of M. grisea spores was dependent on the dose of the chemical.
Apple Proliferation Epidemics Detected in Scab‐Resistant Apple Trees
Authors: Loi N. , Carraro L. , Musetti R. , Firrao G. , Osler R. 
Published: May 2008

AbstractIn the Friuli‐Venezia Giulia, a region of Italy, where serious epidemics of apple proliferation (AP) are known to occur, varieties resistant to scab (Venturia inaequalis (Cke.) Wint.) are increasingly being used in new orchards. The most important cvs are Florina. Prima and Priscilla. These varieties were cultivated according to organic farming regimes with no insecticides used. The results obtained in two orchards during a 7‐year period of investigation indicated that the three varieties resistant to scab are highly susceptible to AP. Florina was most susceptible (high infection rate) to AP while Priscilla was most sensitive (severely affected). The identification of the disease was based on symptom expression, DAPI (4–6‐diamidino‐2‐phenylindole) fluorescence technique, electron microscopy observations and by polymerase chain reaction (PCR). Neither complete spontaneous recovery nor death of AP‐infected plants was noticed. The pattern of natural diffusion of AP does not seem to be uniform, the affected trees may be in line or grouped in certain spots of the orchards. This may indicate the activity of a not very mobile vector. It can be concluded that planting of Florina, Prima and Priscilla should be discouraged in areas where AP is a problem, particularly when organic farming regimes are being applied.
Infection Studies of Cicer arietinum (L.) with GUS‐(E. coli β‐glucuronidase) Transformed Ascochyta rabiei Strains
Authors: Köhler G. , Linkert C. , Barz W. 
Published: May 2008

Abstract Ascochyta rubiei (Pass) Labr. was transformed with the GUS‐(β‐glucuronidase) reporter gene of E. coli. Integration of vector‐DNA into the A. rabiei genome was documented by Southern analysis.To verify that the transformation process had not adversely affected biochemical traits potentially important for fungal pathogenicity. i.e. hydrolytic exoenzymes. the extent of solanapyrone‐toxin production and phytoalexin degradation were measured, Significant differences between the transformants and the wildtype were not observed. Transformants also showed the same degree of virulence as the wildtype A. rabiei strain.Histological studies with the GUS‐transformed genotypes were performed and the time course of infection was monitored by light microscopy. A. rabiei penetrates its host directly through the cuticle and penetration through hydathodes has also been found. After penetration. A. rabiei spreads mainly in the apoplast. When growing through leaflets towards petioles, the fungus could mainly be found in the apoplast and in the cells of phloem, but rarely in xylem. The infection process leads to a total collapse of plant tissue with extensive formation of pycnidia near the vascular tissue.
Barley Yellow Dwarf Virus Strain Incidence in Small Grain Cereals in Northeast Spain
Authors: Comas J. , Pons X. , Albajes R. , Plumb R. T. 
Published: May 2008

AbstractBarley yellow dwarf virus (BYDV) was detected in forage cereals and small grain cereals by indirect enzyme‐linked immunosorbent assay. Samples of forage cereals collected in the winters of 1987/1988, 1988/1989 and 1989/1990 showed that this crop is a reservoir of BYDV during the end of summer and autumn. PAV‐like and MAV‐like isolates, in single or mixed infection, were the most common. The proportion of isolates in the infected samples was relatively stable, Samples of winter cereals collected in the springs of 1988, 1989 and 1990 showed that PAV‐ and MAV‐like isolates were widespread. The proportion of samples infected with PAV‐like isolates was much more variable than that of MAV‐like isolates. The incidence of PAV‐like isolates in winter cereals is more dependent on the population of Rhopalosiphum padi during the winter and early spring, than is the incidence of MAV‐like isolates on Sitobion avenae density. In northeast Spain (Lleida basin) forage cereals are a constant source of PAV‐ and MAV‐ like isolates from which BYDV inoculum is introduced into winter cereals.
Detection by RT‐PCR of Cymbidium Mosaic Virus in Orchids
Authors: Hyun Ryu Ki , Yoon K. E. , Park Won Mok 
Published: May 2008

AbstractThe cymbidium mosaic potexvirus (CyMV) coat‐protein gene was selected for the design of oligonucleotide primers. Reverse transcription‐polymerase chain reaction (RT‐PCR) was performed with 20‐mer CyMV coat‐protein‐specific primers to amplify a 692 base‐pair fragment from crude nucleic acid extracts of virus‐infected orchid‐leaf tissue. The lowest concentration of template viral RNA required to detect the virus was 10 fg. No PCR products were obtained when odontoglossum ringspot virus (ORSV) RNA orextracts of healthy Cymbidium sp. were used as templates in RT‐PCR using the same primers. A 2μl aliquot of crude nucleic‐acid extracts from 0.1 g of the CyMV‐infected leaf tissue was sufficient to yield a diagnostic PCR product.
Structures of Lipopolysaccharide Side‐chains of NCPPB 871, the Neopathotype Strain of Pseudomonas syringae pv. aptata, Strain 299A of pv. pisi and NCPPB 52, the Neopathotype Strain of pv. phaseolicola, in Relation to O‐serogroup
Authors: Spitali M. , Rees N. , Wait R. , Smith A. R. W. 
Published: May 2008

AbstractThe side‐chains of lipopolysaccharides from Pseudomonas syringae pvs. aptata, pisi and phaseolicola contain D‐rhamnose. Using 1H‐and 13C‐nuclear magnetic resonance spectroscopy and methylation analysis, the side‐chains of NCPPB 871, the neopathotype strain of pv. aptata, and strain 299A of pv. pisi race 1 were found to be of identical structure:

image

Side‐chains from NCPPB 52, the neopathotype strain of pv. phaseolicola, were based on the same backbone structure, but were substituted to the extent of approximately 67% with branch D‐fucose residues:

image
Side‐chain structures are correlated with a previously proposed serouping system.
Structures of Lipopolysaccharide Side‐chains of NCPPB 2995, the Neopathotype Strain of Pseudomonas syringae pv. mors‐prunorum and Three Other Strains, in Relation to O‐serogroup
Authors: Spitali M. , Patel M. , Smith A. R. W. 
Published: May 2008

AbstractSide‐chains from the lipopolysaccharides (LPSs) of three virulent isolates of Pseudomonas syringae pv. mors‐prunorum all contained D‐rhamnose. Using Smith degradation, 1H‐ and 13C‐nuclear magnetic resonance spectroscopy, methylation analysis, and GC‐MS, the side‐chain of strain CFBP 2115 was shown to consist of the repeat sequence:

image

NCPPB 2995, the neopathotype strain of P. syringae pv. mors‐prunorum, contained an identical side‐chain, which co‐purified with a glycogen‐like polymer composed of terminal, 1,4,6‐ and 1,4‐linked D‐glucose residues in the ratio 1:1:2.25. The side‐chain of P. syringae pv. mors‐prunorum strain NCPPB 2422 bore the same backbone structure as CFBP 2115, but was substituted by up to 80% with branch D‐fucofuranose residues:

image

From the pattern of hydrolysis by phage A7 rhamnanase, the tetra and trisaccharide repeat sequences appeared to be irregularly interspersed. The side‐chain from LPS of P. syringae pv. syringae strain C414 was of similar structure, but was only 35% fucosylated. Sidechain structures are correlated with a previously proposed serogrouping system.
Complementary DNA Hybridization Analysis of Double‐stranded RNAs Associated with Cucumber Mosaic Virus‐As Strain
Authors: Hyun Ki , Park Won Mok 
Published: May 2008

AbstractVirus‐specific double‐stranded (ds) RNAs were isolated from leaves of Nicotiana tabacum cv. Xanthi‐nc infected with the As or Y strains of cucumber mosaic virus (CMV). These dsRNAs on agarose gels produced 5 bands corresponding, respectively to three genomic RNAs (dsRNAI, −2, −3), the subgenomic mRNA for coat protein (dsRNA4). and satellite dsRNA (dsRNA5) with estimated molecular weights of respectively, 2.5, 2.4, 1.45, 0.69 and 0.28 × 103 kD. In northern‐blot analysis, a 1 kbp complementary DNA (cDNA) to CMV‐As RNA4 hybridized strongly with dsRNA3 and dsRNA4 extracted from CMV‐As infected tobacco, but did not hybridize with dsRNAI, dsRNA2, or satellite dsRNA (dsRNA5). In slot‐blot analysis, the cDNA hybridized strongly with virus‐,specific dsRNAs isolated from CMV infected plants, but not with dsRNAs of TMV‐Korean common, potato virus Y‐VN, or total RNA of healthy tobacco plants.
Epidemiological Aspects of Uromyces appendiculatus on Dry Bean (Phaseolus vulgaris) After Treatment with Bacillus subtilis
Authors: Mizubuti E. S. G. , Maffia L. A. , Muchovei J. J. , Romeiro R. S. , Batista U. G. 
Published: May 2008

AbstractThe number of pustules per leaf area, the average diameters of pustules and average spore production and spore viability were determined on fully expanded primary leaves of dry bean (Phaseolus vulgaris) which had been treated with a suspension of 106 cells of Bacillus subtilis. either as culture broth or as lyophilized broth, 24, 48, 72, 96 or 120 h before inoculation with urediniospores of Uromyces appendiculatus. Urediniospores were collected from treated plants, inoculated to new plants and the number of pustules per leaf area determined. The number of pustules per leaf, spore production per leaf area and the viability of spores were all significantly reduced by previous application of either liquid cultures or lyophilized broth, with greater reductions occurring at shorter intervals before inoculation with U. appendiculatus. There was no effect of treatment on the diameter of pustules. This reduction of disease severity could be of significance in the production of grown beans.
Spatial Dependence in Anthracnose Development in Mixtures of Stylosanthes scabra
Authors: Chakraborty S. , Pettitt A. N. , Choy S. Low , Boland R. M. 
Published: May 2008

AbstractDevelopment of anthracnose caused by Cotletotrichum gloeosporioides in mixtures of the tropical pasture legume Stylosanthes was studied in 3 successive years. The performance of three accessions of Stylosanthes sp., 36260, QiaO42 and 55860 and cv. Seca were evaluated by growing these in three different mixtures with other susceptible or resistant components. Small test plots of these mixtures were established within large grazed background paddocks which were sown to a pure stand of S. scabra cv. Seca or a mixture of six S. scabra genotypes, including ‘Seca’, This simulated the widely used practice of oversowing existing pastures with improved cultivars. In all 3 years, 36260, Q10042, 55860 and ‘Seca’ developed more disease when grown in a mixture with the susceptible ‘Fitzroy’. A hexagonal lattice design was used in the test plots to study the influence of nearest neighbours on the partially resistant 55860. At a plant level, the area under the disease‐progress curve, averaged over the six neighbours, NADPC, was used as a covariate to approximate the influence of inoculitm pressure in th e neighbourhood. The partial regression coefficient for this covariate wa s significant (P < 0.05) for mixture with ‘Fitzroy’ in 1989 and 1990, for mixture with the highly resistant 93116 in 1989, and for mixture with the moderately resistant ‘Verano’ in 1990. The NADPC was further subdivided into three components to separate inoculum pressure due to the component unique to a mixture, the resistant component ‘Seca’ and th e three moderately resistant components 36260, 55860 and Q10042. This showed that the NADPC effect was largely due to inoculum pressure from the moderately resistant components. The study demonstrates the lack of any significant protection of susceptible components from resistant components in the immediate neighbourhood. The practical implication of this finding is that only resistant components should be used when oversowing Stylosanthes pastures.
Characterization of the N Gene of a Groundnut Ringspot Virus (GRSV) Isolate from Argentina
Authors: Dewey R. A. , Semorile L. , Grau O. , De Avila A. C. , Kitajima E. W. 
Published: May 2008

AbstractThis paper describes the characterization of a Tospotirus isolate (M316) from Mendoza, Argentina. The N gene was cloned and sequenced. The sequence obtained was compared with the N gene sequences of other tospoviruses. The percentages of the nucleotide homology and amino acid similarity showed that this isolate may be considered a member of the species groundnut ringspot virus (GRSV). The conclusion drawn from the molecular studies was confirmed by DAS‐ELISA and western blotting. This is thefirst report of GRSV in Argentina, previously described for a South African (SA‐05) and Brazilian (BR‐08) isolates.
Resistance Induced in Potato Tubers by Treatment with Acetylsalicylic Acid to Soft Rot Produced by Erwinia carotovora subsp. carotovora
Authors: López‐López M. J. , Liébana E. , Marcilla P. , Beltrá R. 
Published: May 2008

AbstractAcetylsalicylic acid (aspirin) at concentrations of 0.0125, 0.025, 0.03, 0.04 and 0.05% (w/v) pH 7 does not inhibit bacterial growth of Erwinia carotovora subsp. carotovora‐225 (Ecc‐225); without pH adjustment at concentrations of 0.025 and 0.03%, little inhibition of bacterial growth was observed. However, above 0.04% inhibition was total.When studying the action of acetylsalicylic acid in the soft rot induced by Ecc‐225 on tubers stored at 4 C, we observed that treatments with this compound at concentrations of 0.0125, 0.025 and 0.05% in water adjusted to pH 7, were able to produce a considerable reduction of the soft rot; the possibility of a causal relationship between acetylsalicylic acid treatments of potato tubers and inhibition of soft rot has been established.
Morphology of Phytophthora cinnamomi Isolates from Avocado Orchards in the Coastal Area of Southern Spain
Authors: López‐Herrera C. J. , Pérez‐Jiménez R. M. 
Published: May 2008

AbstractThe morphological characters of 35 isolates of P. cinnamomi collected over a 6‐year period from infected roots of avocado trees from eight different orchards in different parts of Andalusia. southern Spain, were studied.The fact that no fusion organs were found in the single cultures revealed their heterothallic nature. The great similarity and small variation of characters of these Spanish A2 isolates, the hot dry climate, and the fact that the dry cultivated previous crops were olive, grapevine, and almond, are not susceptible to natural infection by P. cinnamomi, suggest that the fungus was not indigenous in this area and was probably introduced on apparently healthy material from California or Mexico.
Quantification of Leptosphaeria maculans Growth in Cotyledons of Brassica napus Using ELISA
Authors: Balesdent M.‐H. , Desthieux I. , Gall C. , Robin P. , Rouxel T. 
Published: May 2008

AbstractThe result of the Leptosphaeria maculans/Brassica napus interaction is usually assessed by symptom scoring following a cotyledon‐inoculation test. However, an early evaluation of the interaction, and reliable quantitaive data of fungal growth inside plant tissues are needed to supplement the visual assessment of the symptoms. For this purpose, we developed a quantitatve double antibody sandwich enzyme‐linked immunosorbent assay (DAS‐ELISA) using rabbit polyclonal antisera directed against soluble mycelial proteins. The specificity of the serum was first assessed by immunoblotting following isoelectric focusing of soluble proteins (Western blot) and by DAS‐ELISA. Except for Alternaria brassicae, no cross‐reactions were observed with my celial extracts of saprophytes or pathogens of B. napus following DAS‐ELISA. Although Tox+ and Tox0 isolates of L. maculans were unequivocally discriminated by Western blot, they were quantitatively indistinguishable following ELISA, thus enabling us to analyse a wide range of L. maculans isolates in planta. The detection limit of the assay was less than 10 ng of fungal proteins per ml of plant extract. For a given isolate, time‐course studies showed that fungal growth in cotyledons was correlated with symptom scoring. In the case of hypersensitive response, only 34% of the plants were ELISA‐positive, and these plants never contained more than 10 ng of fungal protein per cotyledon. In contrast, in the cases, of susceptibility, 100% of the plants were ELISA‐positive and fungal protein content was higher than 10 μg per cotyledon. Moreover, significant differences in ability to colonize the tissues were observed among Tox+ isolates. Finally, using the ELISA quantification, intermediate symptoms could be differentiated as lateresistance responses or susceptibility.
Compartment Analysis of Disease Progression in Time. I. Unrestricted Disease Increase
Authors: Analysis S. 
Published: May 2008

AbstractDisease progression in time through presporulating (latent), sporulating (infectious) and postporulating (removal) stages has been modelled as a three‐compartment system in the case where no upper bound for total disease increase is considered. Deterministic compartment analysis has been performed based on Jeger's linked differential equations. Some important, well‐established epidemilogical principles and concepts have been ‘rediscovered’, clarified or redefined. A new variable, defined as total inoculum reservoir of the host, is suggested as an additional epidemiological concept. Three rate parameters with phytopathological meaning were included in the system: R the constant intrinsic infection rate comparable to the Vanderplankian R,c, h pathogen's ‘hatching rate’, related to the mean latent period p and g the intrinsic removal rate related to the infectious period i. Another parameter λ1 is empirical and comparable to the logarithmic, infection rate, sensu Vanderplank if time becomes very large. In the compartment system iR= 0 is a threshold condition for total disease to increase over initial disease level and iR= 1 is a threshold condition for an ‘explosive’ total disease increase that may induce a large epidemic rather than a threshold for total disease to start or to exist. When iR < 1, the total disease level approaches α asymptotically, a finite value, while when iR > 1, the total disease, increase is explosive; only where λ1=√dh does this increase follows the exponential law at larger t, otherwise the exponential law with the same rate parameter λ1 underestimates or overstimates the amount of total disease at any time t. Some further implications are discussed and compared with those derived from the Vanderplankian system of epidemiological analysis.
Compartment Analysis of Disease Progression in Time. II. Restricted Disease Increase
Authors: Analytis S. 
Published: May 2008

AbstractThree‐compartmenl analysis was performed to describe the disease motion through presporulating (latent), sporulating (infectious) and postsporulating (removal) stages in the general case, where total disease increase is density dependent. A second‐order Runge‐Kutta method for numerical integration of the system of difterential equations was used to solve the equations. Total and postsporulating disease progress curves are S‐shaped while latent and infectious disease progress in the form of optimum curves. The curve of a composite variable defined as total (latent and infectious) inoculum reservoir of the host progresses also in the form of an optimum curve showing a maxi at the total disease level yt/K = 1 − 1/iR, where K is the total population of infection sites, i is the infectious period, R the intrinsic infection rate and iR ≥ 1/(1 − Vo/K). The size of this maxi is a monotone increasing function of the product iR by given initial disease level Vo. Condition iR =1/(1−yo/K) is a threshold condition for total inoculum to increase over yo, or alternatively a threshold condition for a rapid disease increase at the start resulting, possibly, in a large epidemic. Condition iR = O is a threshold condition for total disease to increase over initial disease level. Total disease reaches an asymptotic value less than unity if and only if infectious period is linite (existence of removals). In the compartment system there is a consistency regarding the threshold conditions for total disease to increase over initial disease level in the cases with and without a density‐dependent factor. Conversely, in the Vanderplankian system of differential‐difference equation the threshold conditions are iR = 0 and iR = 1 respectively due to the assumption of an exponential increase of total disease early in the epidemic. The particular cases without latent period and without removals are treated separately. The implications derived from the compartment analysis are compared with those derived from the Vanderplankian system of epidemiological analysis.
Production of the Phytoalexin Resveratrol by Grapes as a Response to Botrytis Attack Under Natural Conditions
Authors: Jeandet P. , Bessis R. , Sbaghi M. , Meunier P. 
Published: May 2008

AbstractResveratrol (3,5,4′‐trihydroxystilbene) is one of the stress metabolites produced by grapevines in response to fungal infection or injury. The distribution of this compound in limited lesions caused by Botrytiscinerea on ripe grape clusters in the vineyard has been examined. Resveratrol was present predominantly in the non‐infected fruits close to the necrotic area. This localized response can help to arrest the spread of established B. cinerea lesions as long as climatic conditions are unfavourable to the pathogen. When conditions become favorable, i.e. after a mild and humid period rapidly spreading lesions are observed on fruits despite the continued increasing production of resveratrol in the grapes which can reach three‐ to five‐fold the value found before rot intensification. Significant amounts of resveratrol can be found prior to any detectable lesions in fruits collected from apparently healthy clusters thus suggesting that phytoalexin response in initiated soon after the recognition of the pathogen by the plant. The involvement of one or more endogenous signals coming from either the fungus or the plant in the induction of host defence responses has also been discussed.
Infection Biology of Bacterial Wilt of Forage Grasses
Authors: Wang Hui Min , Sletten A. 
Published: May 2008

AbstractInfection of perennial ryegrass (Lolium perenne L.), Italian ryegrass (Loliummultiflorum L.), and timothy (Phleum pratense L.) by Xanthomonas campestris pv. graminis and Xanthomonas campestris pv. phlei occurred mainly via wounds rather than natural openings. Nevertheless, bacteria were detected by isolation and immunofluorescence in plants sprayed with the pathogen without prior wounding and in plants in which intact ears had been dipped in inocula. High concentrations of bacteria were observed around the stomata of perennial ryegrass and timothy by scanning electron microscopy 48 h after inoculation. Perennial ryegrass and Italian ryegrass and individual plants of ryegrass and timothy differedin susceptibility to the pathogens.