bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Rapid Seedling Based Screening Technique to Assay Tobacco for Resistance to Phytophthora nicotianae
Authors: Van Jaarsveld E. , Wingfield M. J. , Drenth A. 
Published: July 2003

AbstractBlack shank caused by Phytophthora nicotianae is a serious root and stem disease of cultivated tobacco worldwide. In this study, a rapid seedling‐based screening technique was developed to evaluate tobacco cultivars for resistance to P. nicotianae. This technique was compared with a stem inoculation technique commonly used on adult plants. The overall aim was to develop an improved and rapid technique that could also be used to characterize races of P. nicotianae. A strong positive correlation was found between results of the seedling assay and adult plant trials for all isolates and cultivars tested. Furthermore, P. nicotianae isolates could be characterized as race 0 or 1 using both stem inoculation and the rapid seedling assay. This assay will facilitate rapid and large‐scale screening for black shank resistance and therefore has the potential to reduce yield losses because of this disease in the field.
Relationships of Ceratocystis fimbriata Isolates from Colombian Coffee‐Growing Regions Based on Molecular Data and Pathogenicity
Authors: Marin M. , Castro B. , Gaitan A. , Preisig O. , Wingfield B. D. , Wingfield M. J. 
Published: July 2003

AbstractOne of the most important diseases that reduce the profitability of coffee plantations in Colombia is coffee tree canker. This disease, caused by Ceratocystis fimbriata, has increased in severity and incidence in recent years, resulting in substantial losses to resource‐poor farmers. The aim of this investigation was to consider the relatedness of C. fimbriata isolates from different Colombian coffee‐growing regions, and thus to provide a foundation for future development of resistant coffee varieties. Fifty isolates from 11 provinces were characterized based on morphology and pathogenicity. In addition, isolates were compared using restriction fragment length polymorphisms (RFLPs) and random amplified polymorphic DNA (RAPD) markers. DNA sequence comparisons for the internal transcribed spacer (ITS) region, Mat‐2 HMG Box and partial β‐tubulin gene, were also made. The results of all comparisons clearly showed that Colombian isolates of C. fimbriata are highly variable. All molecular parameters used for these comparisons also showed that C. fimbriata isolates from Colombia reside in two major phylogenetic lineages. We believe that one of these lineages represent C. fimbriata sensu stricto and the other, a new taxon that needs further characterization. Isolates had different levels of pathogenicity on coffee, with some causing death of more that 90% and others killing <5% of inoculated plants. There was also a clear pattern of distribution of the most pathogenic strains within coffee‐growing areas.
Susceptibility of some Mesophilic Hardwoods to Alder Phytophthora
Authors: Santini Alberto , Barzanti Gian Paolo , Capretti Paolo 
Published: July 2003

AbstractInoculation tests were carried out in the greenhouse on seedlings of five hardwoods (Alnus cordata, A. glutinosa, Castanea sativa, Juglans regia and Quercus robur) to determine their susceptibility to an isolate of alder Phytophthora obtained in Italy from A. cordata. A Phytophthora cinnamomi strain was used for comparison. Host susceptibility to infection was determined as the lesion length after stem inoculation and the percentage of necrotized rootlets after soil infestation with inoculated millet seeds. The aggressiveness of the alder Phytophthora isolate was significantly higher in the two Alnus species than in the other hosts. Our results were confirmed with both methods of inoculation. Alnus cordata was consistently the most susceptible host species when compared with the other hardwoods. Damage by P. cinnamomi was severe, particularly after soil infestation tests. The most susceptible species were alders, chestnut and walnut. The test also suggests that alder Phytophthora is able to spread through infected seedlings of different hardwood species.
Induced Resistance against Bipolaris bicolor, Bipolaris sorokiniana and Drechslera tritici‐repentis in Wheat Leaves by Xantham Gum and Heat‐Inactivated Conidial Suspension
Authors: Bach E. E. , Barros B. C. , Kimati H. 
Published: July 2003

AbstractFoliar‐applied xantham gum, commercially available exopolysaccharides from Xanthomonas campestris pv. campestris bacterial capsule, together with conidial suspension of heat‐inactivated pathogens were tested in relation to their ability to induce local and systemic protection against leaf spot diseases caused by Bipolaris sorokiniana, Bipolaris bicolor and Drechslera tritici‐repentis. Xantham gum preparation and heat‐inactivated conidial suspension were effective in inducing local and systemic protection when applied 48 h before the challenge with the pathogen. Microscopic studies of pathogen development in protected and control leaves indicated that neither germination and appressoria formation nor number of papillae were affected by treatment with xantham gum and heat‐inactivated conidial suspension. Increased activity of β‐1,3 glucanases was correlated with the induction of resistance and showed that protection induced in wheat leaves treated with the fungicide propiconazole presented a different mechanism of action.
Non‐pathogenic Powdery Mildews Induce Resistance in Pea (Pisum sativum) against Erysiphe pisi
Authors: Singh U. P. , Bahadur A. , Singh D. P. , Sarma B. K. 
Published: July 2003

AbstractInoculation of pea (Pisum sativum) with pea non‐pathogenic powdery mildews (PNPM) (Oidium sp., Phyllactinia corylea and P. delbergiae) induced resistance against a subsequent infection with Erysiphe pisi. Conidial germination, appressorium formation and secondary branch development in E. pisi conidia on pea plants were reduced in the presence of the three PNPM compared with uninoculated host plants. Microscopical observations also revealed that there was no hypersensitive cell death or lignin formation in the pea leaf tissues following treatment with the three PNPM. Reduced disease intensity (DI) of pea powdery mildew was observed up to 12 days after inoculation of the three PNPM. Pre‐inoculation with P. corylea led to the highest disease suppression (21.2% DI) compared with non‐inoculated control plants (96.5% DI). High‐performance liquid chromatographic (HPLC) analysis of different parts of pea plants with and without PNPM inoculation revealed increased synthesis of total phenolics and also of gallic, tannic and ferulic acids. However, the amount of phenolic compounds decreased in leaves treated singly with E. pisi or in combination with the PNPM.
Pathotype Separation of Plasmodiophora brassicae by the Host Plant
Authors: Fähling M. , Graf H. , Siemens J. 
Published: July 2003

AbstractDifferent pathotypes existing in the field isolate ‘e’ of Plasmodiophora brassicae were separated by repeated propagation in resistant host plants or by inoculation with single spores. The resulting isolates were studied by combining the molecular markers of fingerprint‐like patterns and characterization of pathogenic capacity using genetically homogenous Arabidopsis ecotypes under controlled environmental conditions, so that the selection of virulent pathotypes within resistant host plants could be demonstrated. These host‐selected isolates shared the molecular and phytopathological characters of corresponding single‐spore isolates.
Sterol Composition of DMI‐Resistant and ‐Sensitive Field Isolates of Cercospora beticola
Authors: Karaoglanidis G. S. , Menkissoglu‐Spiroudi U. , Thanassoulopoulos C. C. 
Published: July 2003

AbstractThe effect of the sterol 14α‐demethylase‐inhibitor (DMI) fungicide flutriafol, on the sterol composition of DMI‐sensitive and ‐resistant strains of Cercospora beticola, was studied. In the absence of flutriafol, these strains had the same sterol composition regardless of their sensitivity to DMIs, with ergosterol the major sterol in the fungal membranes. Following treatment with flutriafol, the desmethyl sterols decreased and the eburicol, obtusifoliol and 14α‐methylergosta‐8,14, 24(28)‐trienol content increased, indicating that sterol 14α‐demethylase activity was inhibited in all C. beticola strains tested. In the resistant strains, C14‐methyl‐sterols accumulated at a higher flutriafol concentration than they did in the sensitive strains. The results demonstrate that DMI‐resistance in C. beticola is not conferred a sterol 14α‐demethylase deficiency, suggesting an alternative mechanism in the observed resistance phenotypes.
Macerating Enzymes Produced by Rhizopus oryzae in Infected Mulberry Roots
Authors: Yoshida S. , Tsuyumu S. , Tsukiboshi T. 
Published: July 2003

Abstract Rhizopus oryzae, the causal agent of Rhizopus rot of mulberry, was examined for its ability to produce macerating enzymes in planta and in vitro. When segments of healthy mulberry roots were immersed for 24 h at 30°C in pH‐adjusted crude extracts from roots of mulberry infected naturally or inoculated with R. oryzae, or in the culture filtrate of the fungus in liquid medium containing mulberry roots or pectin, maceration measured by the weight decrease of the immersed segment was detected in all of these crude extracts, and the highest activity was observed under acidified conditions. Activities of cellulase, polygalacturonase, pectate lyase, and pectin lyase, but not protease were detected in crude extracts of the fungus‐inoculated roots and in culture supernatant in liquid medium containing the roots. These results suggest that these macerating enzymes are produced in the infected roots. The crude extract of the fungal culture grown in pectin liquid medium, which also macerated the roots, showed only the activity of three pectic enzymes (polygalacturonase, pectate lyase and pectin lyase). Polygalacturonase may play an essential role in the maceration of mulberry roots by R. oryzae.
Aspects of the Biology and Control of Benzimidazole Resistant Isolates ofPhoma clematidina, cause of Leaf Spot and Wilt in Clematis
Authors: Van De Graaf P. , O'Neill T. M. , Chartier‐Hollis J. M. , Joseph M. E. 
Published: July 2003

AbstractIsolates ofPhoma clematidina, the cause of clematis wilt, were recovered from diseased clematis plants throughout England and testedin vitroandin vivofor their sensitivity to benzimidazole fungicides. More than one third of 14 isolates tested on fungicide‐amended agar plates were found to be highly resistant to products containing carbendazim, benomyl or thiophanate‐methyl. On unamended agar, the growth and morphology of benzimidazole resistant and sensitive isolates ofP. clematidinawere clearly distinct; on attached clematis leaves not treated with fungicide, the resistant isolates were markedly less virulent than the sensitive ones. In a 3‐month trial onClematiscv. Henryi, high volume sprays of a fungicide containing carbendazim reduced the incidence of leaf spotting caused by a benzimidazole sensitive isolate ofP. clematidinaby almost 80% but gave no significant reduction in disease caused by a resistant isolate. Fungicides found to be very effective against both benzimidazole sensitive and resistant isolates were products containing difenoconazole, azoxystrobin or kresoxim‐methyl. This is the first report of benzimidazole resistance inP. clematidinain the UK. Our findings indicate that growers should consider alternative fungicides and non‐chemical methods for the prevention and control of clematis wilt.
Vegetative Compatibility and Pathogenicity of Verticillium dahliae Kleb. Isolates from Olive in Israel
Authors: Tsror (Lahkim) L. , Levin A. G. 
Published: July 2003

AbstractFifty‐two isolates of Verticillium dahliae from olive trees grown at different locations in Israel were assigned to vegetative compatibility groups (VCGs), using nitrate non‐utilizing (Nit) mutants. A higher frequency of nit1/nit3 mutants (95%) was obtained compared with NitM (5%), with 81% of the isolates being assigned to VCG4B and 19% to VCG2A. The pathogenicity of 14 randomly selected isolates (seven of each VCG) was tested on olive twigs (cv. Picual) and tomato. VCG4B and VCG2A isolates were similarly aggressive on olive. However, VCG2A isolates were more aggressive on tomato (line 139) than the VCG4B isolates as indicated by a higher colonization index.
Osmotic Potential Effects on In Vitro Growth, Morphology and Pathogenicity of Macrophomina phaseolina
Authors: Cervantes‐García D. , Saúl Padilla‐Ramírez J. , Simpson J. , Mayek‐Pérez N. 
Published: July 2003

AbstractThe influence of osmotic potential (Ψs) on in vitro growth and morphology of four isolates of Macrophomina phaseolina was studied using potato‐glucose‐agar adjusted to different osmotic potentials with KCl, NaCl and sucrose. The effect of NaCl on M. phaseolina pathogenicity in common bean was determined and then related to the pathogenicity of each isolate on seeds of 12 differential common bean cultivars. The three sources of Ψs reduced M. phaseolina growth under in vitro conditions, whereby NaCl caused the highest negative effects. The high solute concentrations reduced the synthesis of mycelial pigments and the size and shape of microsclerotia. Pathogenicity of M. phaseolina in common bean seeds was reduced by high concentrations of NaCl but no relationship was found between the tolerance to high Ψs concentrations under in vitro conditions and M. phaseolina pathogenicity in common bean seeds.
Interactions between the Grasses Phalaris arundinacea, Miscanthus sinensis and Echinochloa crus‐galli, and Barley and Cereal Yellow Dwarf Viruses
Authors: Lamptey J. N. L. , Plumb R. T. , Shaw M. W. 
Published: July 2003

AbstractThe grass species Miscanthus sinensis, Echinochloa crus‐galli and Phalaris arundinacea may be useful biomass crops. In glasshouse inoculations with two isolates of Barley yellow dwarf virus (BYDV)‐MAV and BYDV‐PAV and one of Cereal yellow dwarf virus (CYVD)‐RPV, E. crus galli was infected by all three virus isolates, P. arundinacea by BYDV‐MAV and CYDV‐RPV, but M. sinensis only by BYDV‐MAV. All three hosts became very difficult to infect after several weeks’ growth. Symptoms were inconspicuous; dry matter yield losses ranged from c. 20–40%. Aphids acquired all three virus isolates from E. crus‐galli, but more efficiently from 5 than 26‐week‐old plants. Only BYDV‐MAV was acquired from P. arundinacea and M. sinensis. Plants of each species and of Avena sativa were grown outdoors between May and July in 1994 and 1995. Young plants of each species were exposed for successive 2‐week intervals during the same periods. Vector populations were higher on A. sativa and P. arundinacea than on E. crus‐galli and M. sinensis, and more plants of these species became infected. In 1994 only BYDV‐MAV was detected. In 1995 BYDV‐MAV, BYDV‐PAV and CYDV‐RPV were all detected; BYDV‐MAV was again the virus isolate most frequently found.
Sensitive Detection of Artichoke Latent Virus in Globe Artichoke Field Samples by One‐step RT‐PCR or Tissue Imprint Hybridization
Authors: Lumia V. , Pasquini G. , Barba M. 
Published: July 2003

Abstract Artichoke latent virus (ArLV) is one of the most economically important and widely distributed viruses of artichoke in the Mediterranean area. The availability of a sensitive and reliable diagnostic method is a prerequisite for evaluating the sanitary status of globe artichoke plants. We report here two molecular methods for the detection of ArLV. The first consists of RNA extraction from infected leaf tissue using a commercial kit, followed by a one‐step reverse transcription polymerase chain reaction (RT‐PCR) protocol, using primers designed in this investigation. The second is based on the tissue imprint hybridization technique, using a denatured digoxigenin‐labelled ArLV DNA probe. Both methods were effective in detecting ArLV in late globe artichoke plant samples.
The Association of Aster Yellows Phytoplasma with Rose Dieback Disease in Poland
Authors: Kamińska M. , Śliwa H. , Malinowski T. , Skrzypczak Cz. 
Published: July 2003

AbstractPolymerase chain reaction (PCR) assay, restriction fragment length polymorphism analysis, sequencing of PCR‐amplified cDNA, graft transmission and mycological tests were used to investigate the possible association of phytoplasma infection with rose dieback symptoms and to identify any associated pathogen. Rose plants with shoot dieback symptoms, symptomless rose plants, and experimentally infected periwinkle seedlings were shown to be infected with phytoplasma, which was classified to the aster yellows (AY) group, subgroup 16SrI‐B, based on the analysis of the nucleotide sequence of a 1101‐bp fragment of 16S rRNA gene (GenBank accession no. AF450325). No evidence was obtained for the infection of rose plants with Verticillium albo‐atrum. The rose plants cultivated under plastic cover without heating or under outdoor conditions, in contrast to greenhouse‐grown roses, developed downy mildew symptoms caused by Peronospora sparsa.
Unique pattern of urinary tract calculi in Australian Aboriginal children
Authors: Carson PJ , Brewster DR 
Published: July 2003

Abstract Young Aboriginal children in remote regions of tropical and desert Australia are at risk of developing urate stones in their upper urinary tract from an early age. These radiolucent calculi were only recognized with the availability of ultrasound diagnosis and are not associated with anatomic anomalies or abnormal uric acid production/metabolism. Although these stones appear to resolve spontaneously after the weaning period, some result in ureteric obstruction and infection which may lead to renal damage. This pattern of urolithiasis differs from the usual global urolithiasis pattern of either endemic bladder stones in young children in developing countries or predominantly calcium‐based stones in upper tracts of older children and adults in affluent industrialized countries, where upper tract urate stones account for only a minority of childhood urinary tract stones. Risk factors for urate stones are low urine output and acidic urine. An association between urolithiasis and carbohydrate intolerance leading to chronic acidosis has been suggested for Aboriginal children, but existing limited evidence does not support this as a major aetiological factor. Although further studies on the epidemiology, natural history and management of these urate stones are needed, we believe the focus should be on improving the known social and environmental risk factors of remote Aboriginal children during the weaning period which contribute to the unacceptably high prevalence of failure to thrive, diarrhoeal disease, environmental enteropathy, iron deficiency and urolithiasis.
Cows milk consumption in constipation and anal fissure in infants and young children
Authors: Andıran F , Dayı S , Mete E 
Published: July 2003

Objective:  To examine daily cows milk consumption and duration of breastfeeding in infants and young children with anal fissure and constipation.Methods:  Two groups of 30 consecutive children aged between 4 months and 3 years were evaluated retrospectively. Group I comprised children with chronic constipation and anal fissure in whom surgical causes were excluded, and group II comprised normal children. The daily consumption of cows milk, duration of breastfeeding and other clinical features of the children were investigatedResults:  The mean daily consumption of cows milk was significantly higher in group I (756 mL, range 200−1500 mL) than group II (253 mL, range 0−1000 mL) (P < 0.001). Group I children were breastfed for a significantly shorter period (5.8 months, range 0−18 months) than group II (10.1 months, range 2−24 months) (P < 0.006). The odds ratios for the two factors − children consuming more than 200 mL of cows milk per day (25 children in group I, 11 children in group II) and breastfeeding for less than 4 months (16 children in group I, 5 children in group II) − were calculated to be 8.6 (95% confidence interval [CI]: 0.23−0.74, P = 0.0005) and 5.7 (95% CI: 0.37−0.66, P = 0.007), respectively.Conclusions:  Infants and young children with chronic constipation and anal fissure may consume larger amounts of cows milk than children with a normal bowel habit. Additionally, shorter duration of breastfeeding and early bottle feeding with cows milk may play a role in the development of constipation and anal fissure in infants and young children.
Antimicrobial resistance in Helicobacter pylori isolates from children
Authors: Rerksuppaphol S , Hardikar W , Midolo PD , Ward P 
Published: July 2003

Objective:  To determine the resistance rate to four antimicrobial agents commonly used in the treatment of Helicobacter pylori infection in children.Methods:  Between July 1997 and January 2000, all H. pylori isolates from children undergoing gastroscopy were prospectively collected and subcultured to yield the susceptibility to four antimicrobial agents by E‐test. In all, 23 isolates were tested. Demographic data, presenting symptoms, treatment regimen and clinical improvement after treatment were collected retrospectively.Results:  The resistance rate of H. pylori to metronidazole and clarithromycin were 43.5% and 8.7%, respectively. No H. pylori strains were resistant to amoxycillin or tetracycline. There were no statistically significant differences in age, sex, ethnicity, presenting symptoms or clinical improvement after treatment between antimicrobial‐susceptible and antimicrobial‐resistant groups.Conclusions:  The frequent resistance of H. pylori to metronidazole and moderate resistance to clarithromycin in children are comparable with local adult data. The incidence of resistance tended to be higher in patients of non‐European ethnicity, but this was not statistically significant. Given that the primary goal of therapy is eradication, and that local resistance rates are high, recommendations for H. pylori management may need to be modified to include sensitivity testing and/or determination of eradication in all patients.
Acute disseminated encephalomyelitis: A review of 18 cases in childhood
Authors: Gupte G , Stonehouse M , Wassmer E , Coad NAG , Whitehouse WP 
Published: July 2003

Objective:  Acute disseminated encephalomyelitis (ADEM) is a treatable inflammatory demyelinating disorder seen more commonly in children than in adults. It typically presents to general paediatricians, often, like encephalitis, with non‐specific cerebrospinal fluid findings. The brain computerized tomography scan is usually normal, so is falsely reassuring and delays the diagnosis, which might result in considerable morbidity. The present study was initiated to report on the various modes of presentation and raise the awareness of the diagnosis of ADEM among general paediatricians.Methods:  A retrospective review of the case notes of 18 children with a diagnosis of ADEM established in a tertiary referral centre from 1995 to 2000 was undertaken with particular reference to clinical features, investigations and treatment.Results:  The most common presenting features were ataxia (10 cases), followed by headache (eight cases) and weakness (five cases). Magnetic resonance imaging (MRI) of the brain was needed to confirm the diagnosis in all 18 children. Treatment usually included a course of intravenous methylprednisolone followed by a tapering dose of oral prednisolone over several weeks. Although the outcome for most of the children was generally good, two relapsed after cessation of steroids and five children had ongoing disabilities.Conclusions:  The investigation of choice for establishing the diagnosis of ADEM was MRI of the brain. Other investigations were seldom helpful in reaching the diagnosis. Early diagnosis and prompt treatment of ADEM will probably reduce morbidity.