title stringlengths 0 1.13k | abstract stringlengths 1 15.7k | PMID int64 22 36.5M |
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The Complete Nucleotide Sequence and Biotype Variability of Papaya leaf distortion mosaic virus. | ABSTRACT The complete nucleotide sequence of the genome of Papaya leaf distortion mosaic virus (PLDMV) was determined. The viral RNA genome of strain LDM (leaf distortion mosaic) comprised 10,153 nucleotides, excluding the poly(A) tail, and contained one long open reading frame encoding a polyprotein of 3,269 amino aci... | 18,943,981 |
Different Resistance Mechanisms of Medicago truncatula Ecotypes Against the Rust Fungus Uromyces striatus. | ABSTRACT A pathosystem consisting of the model plant Medicago truncatula and the rust fungus Uromyces striatus was characterized. From a collection of 113 mostly European accessions of M. truncatula, the vast majority were found to be susceptible to U. striatus, whereas 5 accessions showed strong resistance reactions. ... | 18,943,984 |
A one-step reverse transcription-polymerase chain reaction system for the simultaneous detection and identification of multiple tospovirus infections. | ABSTRACT A one-step reverse transcription-polymerase chain reaction (RT-PCR) method has been developed for the simultaneous detection and identification of multiple tospoviruses that infect plants. The RT-PCR system is composed of six primers in a single tube: a universal degenerate primer and five virus species-specif... | 18,943,986 |
Inducible Expression of a Phytolacca heterotepala Ribosome-Inactivating Protein Leads to Enhanced Resistance Against Major Fungal Pathogens in Tobacco. | ABSTRACT Plant genetic engineering has long been considered a valuable tool to fight fungal pathogens because it would limit the economically costly and environmentally undesirable chemical methods of disease control. Ribosome-inactivating proteins (RIPs) are potentially useful for plant defense considering their antiv... | 18,943,992 |
Population Structure of Mycosphaerella graminicola: From Lesions to Continents. | ABSTRACT The genetic structure of field populations of Mycosphaerella graminicola was determined across a hierarchy of spatial scales using restriction fragment length polymorphism markers. The hierarchical gene diversity analysis included 1,098 isolates from seven field populations. Spatial scales ranged from millimet... | 18,944,019 |
Internal Transcribed Spacer Regions 1 and 2 and Random Amplified Polymorphic DNA Analysis of Didymella bryoniae and Related Phoma Species Isolated from Cucurbits. | ABSTRACT Didymella bryoniae (anamorph Phoma cucurbitacearum) is the causal agent of gummy stem blight, although other Phoma species are often isolated from cucurbit plants exhibiting symptoms of the disease. The molecular and phylogenetic relationships between D. bryoniae and these Phoma species are unknown. Isolates o... | 18,944,025 |
Risk Analysis of Brown Rot Blossom Blight of Prune Caused by Monilinia fructicola. | Experiments under controlled environmental conditions were conducted during bloom of prune (Prunus domestica, L.) in 1999 and 2000 to assess the effects of inoculum concentration (IC), wetness duration (WD), temperature, and bloom stages on development of brown rot blossom blight of prunes. Branches from trees of a pru... | 18,944,033 |
Plant pathogen culture collections: it takes a village to preserve these resources vital to the advancement of agricultural security and plant pathology. | ABSTRACT Plant pathogen culture collections are essential resources in our fight against plant disease and for connecting discoveries of the present with established knowledge of the past. However, available infrastructure in support of culture collections is in serious need of improvement, and we continually face the ... | 18,944,046 |
Clarification of the Etiology of Glomerella Leaf Spot and Bitter Rot of Apple Caused by Colletotrichum spp. Based on Morphology and Genetic, Molecular, and Pathogenicity Tests. | ABSTRACT Morphological characteristics and vegetative compatibility groups (VCGs) of 486 isolates of Glomerella cingulata, Colletotrichum gloeosporioides, and C. acutatum collected from apple leaves with Glomerella leaf spot (GLS) symptoms and fruit with bitter rot symptoms in the United States and Brazil were studied.... | 18,944,054 |
Activity of the Antifungal Protein from Aspergillus giganteus Against Botrytis cinerea. | ABSTRACT Botrytis blight (gray mold), caused by Botrytis cinerea, is one of the most widely distributed diseases of ornamental plants. In geranium plants, gray mold is responsible for important losses in production. The mold Aspergillus giganteus is known to produce and secrete a basic low-molecular-weight protein, the... | 18,944,061 |
Ecological implications from a molecular analysis of phytoplasmas involved in an aster yellows epidemic in various crops in Texas. | ABSTRACT In the spring of 2000, an aster yellows (AY) epidemic occurred in carrot crops in the Winter Garden region of southwestern Texas. A survey revealed that vegetable crops, including cabbage, onion, parsley, and dill, and some weeds also were infected by AY phytoplasmas. Nested polymerase chain reaction (PCR) and... | 18,944,064 |
Use of a Nitrate-Nonutilizing Mutant and Selective Media to Examine Population Dynamics of Fusarium oxysporum f. sp. spinaciae in Soil. | ABSTRACT Determining the population density of the spinach wilt pathogen Fusarium oxysporum f. sp. spinaciae in soil with conventional Fusarium-selective media is quite difficult because nonpathogenic strains of F. oxysporum also grow on those media and are indistinguishable from the pathogen. Therefore, a nitrate-nonu... | 18,944,103 |
Depth Distribution of Rotylenchulus reniformis Under Different Tillage and Crop Sequence Systems. | ABSTRACT The population density of the reniform nematode, Rotylenchulus reniformis, was monitored at depths of 0 to 30, 30 to 60, 60 to 90, and 90 to 120 cm in a tillage and crop sequence trial in south Texas in 2000 and 2001. Main plots were subjected to three different tillage systems: conventional tillage (moldboard... | 18,944,104 |
Investigating the Spatiotemporal Genetic Structure of Phytophthora capsici in Michigan. | ABSTRACT Phytophthora capsici isolates were recovered from pepper and cucurbit hosts at seven locations in Michigan from 1998 to 2000. Isolates were characterized for compatibility type (CT), mefenoxam sensitivity (MS), and amplified fragment length polymorphism (AFLP) marker profiles. In total, 94 AFLP bands were reso... | 18,944,124 |
Characterization and mapping of oat crown rust resistance genes using three assessment methods. | ABSTRACT Resistance is the primary means of control for crown rust of oat (Avena sativa L.), caused by Puccinia coronata f. sp. avenae, and better knowledge of the genetics of resistance will enhance resistance breeding. Disease data were generated in the field and greenhouse for parents and recombinant inbred lines of... | 18,944,171 |
Edaphic Soil Levels of Mineral Nutrients, pH, Organic Matter, and Cationic Exchange Capacity in the Geocaulosphere Associated with Potato Common Scab. | ABSTRACT In order to determine possible relationships between geocaulosphere soil properties and severity of common scab of potato caused by Streptomyces scabies, soils were collected from representative commercial potato fields in Canada: in Simcoe and Dufferin Counties, Ontario and across Prince Edward Island (PEI) i... | 18,944,172 |
Using the TxtAB operon to quantify pathogenic Streptomyces in potato tubers and soil. | The phytotoxin thaxtomin, produced by plant pathogenic Streptomyces species, is the only known pathogenicity determinant for common scab diseases of potato and other root and tuber crops. Genes encoding thaxtomin synthetase (txtAB) are found on a pathogenicity island characteristic of genetically diverse plant pathogen... | 18,944,188 |
Variation in Albicidin Biosynthesis Genes and in Pathogenicity of Xanthomonas albilineans, the Sugarcane Leaf Scald Pathogen. | ABSTRACT Total genomic DNA from 137 strains of Xanthomonas albilineans from worldwide locations was hybridized with two DNA probes that together harbor the entire 49-kb albicidin biosynthesis gene cluster and two additional 3-kb genomic regions required for albicidin production. Fourteen haplotypes and two major geneti... | 18,944,203 |
Strawberry Anthracnose: Histopathology of Colletotrichum acutatum and C. fragariae. | ABSTRACT Ontogeny of the invasion process by Colletotrichum acutatum and C. fragariae was studied on petioles and stolons of the strawberry cultivar Chandler using light and electron microscopy. The invasion of host tissue by each fungal species was similar; however, each invasion event occurred more rapidly with C. fr... | 18,944,215 |
Silicon-induced cell wall fortification of rice leaves: a possible cellular mechanism of enhanced host resistance to blast. | ABSTRACT Locations of silicon accumulation in rice leaves and its possible association with resistance to rice blast were investigated by electron microscopy and X-ray microanalysis. A blast-susceptible cultivar, Jinmi, and a partially resistant cultivar, Hwaseong, were grown under a hydroponic culture system with modi... | 18,944,220 |
Resistance to Bean pod mottle virus in Transgenic Soybean Lines Expressing the Capsid Polyprotein. | ABSTRACT Transgenic fertile soybean plants were generated from somatic embryos of soybean (Glycine max) cv. Jack transformed via particle bombardment with the capsid polyprotein (pCP) gene of Bean pod mottle virus(BPMV). The plant transformation vector (pHIG/BPMV-pCP) utilized in these experiments contained the BPMV-pC... | 18,944,228 |
Aspergillus flavus and Aflatoxin Contamination of Leguminous Trees of the Sonoran Desert in Arizona. | ABSTRACT Aspergillus spp. in section Flavi were frequently associated with desert tree legumes in uncultivated areas of the Sonoran Desert. Of 270 samples of debris and fruits of mesquite (Prosopis spp.), ironwood (Olneya tesota), acacia (Acacia spp.), and palo verde (Cercidium and Parkinsonia spp.), 87% were positive ... | 18,944,238 |
Maize fine streak virus, a New Leafhopper-Transmitted Rhabdovirus. | ABSTRACT A previously uncharacterized virus was isolated from fall-planted sweet corn (Zea mays L., Syngenta GSS 0966) leaves showing fine chlorotic streaks. Symptomatic plants were negative in enzyme-linked immunosorbent assay against many maize viruses, but reacted weakly with antisera to Sorghum stunt mosaic virus s... | 18,944,241 |
Detection of two orchid viruses using quartz crystal microbalance-based DNA biosensors. | ABSTRACT We have developed a piezoelectric DNA-sensor based on DNA-RNA hybridization for the detection of two orchid viruses, Cymbidium mosaic virus (CymMV) and Odontoglossum ringspot virus (ORSV). Specific oligonucleotide probes modified with a mercaptohexyl group at the 5'-phosphate end were directly immobilized onto... | 18,944,263 |
Protection against pathogen and salt stress by four plant growth-promoting rhizobacteria isolated from Pinus sp. on Arabidopsis thaliana. | The ability of four plant growth-promoting rhizobacteria, isolated in a previous study, to induce systemic resistance on Arabidopsis thaliana Col 0 against biotic and abiotic stress was evaluated. All the bacteria enhanced protection against the foliar pathogen Pseudomonas syringae DC3000 and increased plant tolerance ... | 18,944,290 |
Capsicum Species: Symptomless Hosts and Reservoirs of Tomato yellow leaf curl virus. | ABSTRACT Five Capsicum species were tested for susceptibility to Tomato yellow leaf curl virus (TYLCV) and the mild strain of TYLCV (TYLCV-Mld). TYLCV was able to infect 30 of 55 genotypes of C. annuum, one of six genotypes of C. chinense, one of two genotypes of C. baccatum, and the only genotype of C. frutescens test... | 18,944,303 |
Identification and Characterization of Benomyl-Resistant and -Sensitive Populations of Colletotrichum gloeosporioides from Statice (Limonium spp.). | ABSTRACT Sixty-four isolates of Colletotrichum gloeosporioides were isolated from infected Limonium spp. cultivated in 12 different locations in Israel. All isolates were identified as belonging to the C. gloeosporioides complex by species-specific primers. Of these isolates, 46 were resistant to benomyl at 10 mug/ml a... | 18,944,315 |
Genotyping of Serratia marcescens Strains Associated with Cucurbit Yellow Vine Disease by Repetitive Elements-Based Polymerase Chain Reaction and DNA-DNA Hybridization. | ABSTRACT The bacterium that causes cucurbit yellow vine disease (CYVD) has been placed in the species Serratia marcescens based on 16S rDNA and groE sequence analysis. However, phenotypic comparison of the organism with S. marcescens strains isolated from a variety of ecological niches showed significant heterogeneity.... | 18,944,323 |
Interactions Between Geminiviruses in a Naturally Occurring Mixture: Pepper huasteco virus and Pepper golden mosaic virus. | ABSTRACT Pepper huasteco virus (PHV) and Pepper golden mosaic virus (PepGMV) are found in mixtures in many horticultural crops in Mexico. This combination constitutes an interesting, naturally occurring model system to study several aspects of virus-virus interactions. Possible interactions between PHV and PepGMV were ... | 18,944,336 |
Induction of Chitinase, beta-1,3-Glucanase, and Phenylalanine Ammonia Lyase in Peach Fruit by UV-C Treatment. | ABSTRACT Treatment of peach fruit with UV-C light caused a rapid induction of chitinase, beta-1,3-glucanase, and phenylalanine ammonia lyase (PAL) activities starting 6 h after treatment and reaching maximum levels at 96 h after treatment. By 96 h after UV-C treatment, chitinase, beta-1,3-glucanase, and PAL activities ... | 18,944,346 |
Evaluation of local and imported fire blight warning systems in Israel. | ABSTRACT The possibility of using local and imported warning systems for the management of fire blight (caused by the bacterium Erwinia amylovora) in pears was tested in Israel from 1997 to 2000. Three imported systems (MARYBLYT 4.3, BIS95, and Cougarblight 98C) and one local system (Fire Blight Control Advisory [FBCA]... | 18,944,347 |
The Identification of Two New Races of Pyrenophora tritici-repentis from the Host Center of Diversity Confirms a One-to-One Relationship in Tan Spot of Wheat. | ABSTRACT Pyrenophora tritici-repentis, causal agent of tan spot, induces necrosis and chlorosis in its wheat host. The tan spot system conforms to the toxin model and three host-specific toxins have been identified (Ptr ToxA, Ptr ToxB, and putative Ptr ToxC). Processing of a collection of isolates, obtained in the Fert... | 18,944,352 |
Defense Gene Expression Analysis of Arabidopsis thaliana Parasitized by Orobanche ramosa. | ABSTRACT The infection of Arabidopsis thaliana roots with the obligate parasite Orobanche ramosa represents a useful model for a study of the molecular events involved in the host plant response to a parasitic plant attack. To avoid analysis problems due to the subterranean development of O. ramosa, we developed two in... | 18,944,360 |
Sequence tagged site markers to rsp1, rsp2, and rsp3 genes for resistance to septoria speckled leaf blotch in barley. | ABSTRACT Five random amplified polymorphic DNA markers, two in coupling (OPAH5(545C), and OPBA12(314C)) and three in repulsion phase (UBC285(158R), OPC2(441R), and OPB17(451R)), closely linked to Rsp genes conferring resistance to Septoria speckled leaf blotch (SSLB), were identified using bulked segregant analysis in ... | 18,944,371 |
Characterization of early leaf spot suppression by strip tillage in peanut. | ABSTRACT Epidemics of early leaf spot of peanut (Arachis hypogaea), caused by Cercospora arachidicola, are less severe in strip-tilled than conventionally tilled fields. Experiments were carried out to characterize the effect of strip tillage on early leaf spot epidemics and identify the primary target of suppression u... | 18,944,374 |
Chitinases from the Plant Disease Biocontrol Agent, Stenotrophomonas maltophilia C3. | ABSTRACT Stenotrophomonas maltophilia strain C3, a biocontrol agent of Bipolaris sorokiniana in turfgrass, produced chitinases in broth media containing chitin. Chitinases were partially purified from culture fluid by ammonium sulfate precipitation and chitin affinity chromatography. The chromatography fraction with th... | 18,944,395 |
Temporal and Spatial Patterns of Genetic Structure of Phytophthora infestans from Tomato and Potato in the Del Fuerte Valley. | ABSTRACT The temporal and spatial patterns of Phytophthora infestans population genetic structure were analyzed in the Del Fuerte Valley, Sinaloa, Mexico, during the crop seasons of 1994 to 1995, 1995 to 1996, and 1996 to 1997 by geographical information systems. Isolates of P. infestans were obtained from infected tis... | 18,944,419 |
An Elicitor from Botrytis cinerea Induces the Hypersensitive Response in Arabidopsis thaliana and Other Plants and Promotes the Gray Mold Disease. | ABSTRACT Botrytis cinerea is a necrotrophic fungus that infects over 200 plant species. Previous studies showed that host cells collapse in advance of the hyphae, suggesting secretion of toxins or elicitors. We have partially characterized elicitor activity from intercellular fluid extracted from Arabidopsis thaliana l... | 18,944,445 |
Necrotic Lesion Resistance Induced by Peronospora tabacina on Leaves of Nicotiana obtusifolia. | ABSTRACT Infection of Nicotiana obtusifolia plant introduction (PI) #555573 by the downy mildew pathogen Peronospora tabacina resulted in a compatible interaction, in which P. tabacina penetrated and freely colonized host leaf tissue. This interaction became incompatible 5 to 6 days later, with the appearance of necrot... | 18,944,453 |
Formulation of Bacillus spp. for Biological Control of Plant Diseases. | ABSTRACT Maximizing the potential for successfully developing and deploying a biocontrol product begins with a carefully crafted microbial screening procedure, proceeds with developing mass production protocols that optimize product quantity and quality, and ends with devising a product formulation that preserves shelf... | 18,944,465 |
Analysis of Host Species Specificity of Magnaporthe grisea Toward Wheat Using a Genetic Cross Between Isolates from Wheat and Foxtail Millet. | ABSTRACT A genetic cross was performed between a Setaria isolate (pathogenic on foxtail millet) and a Triticum isolate (pathogenic on wheat) of Magnaporthe grisea to elucidate genetic mechanisms of its specific parasitism toward wheat. A total of 80 F(1) progenies were obtained from 10 mature asci containing 8 ascospor... | 18,944,467 |
Assessment of Diversity in Claviceps africana and Other Claviceps Species by RAM and AFLP Analyses. | ABSTRACT Genetic diversity among isolates of Claviceps africana, the sorghum ergot pathogen, and isolates of other Claviceps spp. causing ergot on sorghum or other hosts, was analyzed by random amplified microsatellite (RAM) and amplified fragment length polymorphism (AFLP) analyses. Of the RAM primer sets tested, one ... | 18,944,476 |
Evaluation of Infection Processes and Resulting Disease Caused by Dendryphion penicillatum and Pleospora papaveracea on Papaver somniferum. | ABSTRACT Two pathogenic fungi of opium poppy, Pleospora papaveracea and Dendryphion penicillatum, were isolated from field material in Beltsville, MD. The processes of infection by these two fungi were studied to determine the optimal environmental conditions for infection. Both fungi formed appressoria capable of pene... | 18,944,488 |
Evidence for Antibiosis and Induced Host Defense Reactions in the Interaction Between Verticillium lecanii and Penicillium digitatum, the Causal Agent of Green Mold. | ABSTRACT Chronological events of the intercellular interaction between Verticillium lecanii and the postharvest pathogen Penicillium digitatum were investigated by transmission electron microscopy and gold cytochemistry. Growth inhibition of P. oligandrum as a response to V. lecanii attack correlated with striking host... | 18,944,516 |
Quantitative trait Loci associated with resistance to gray leaf spot of corn. | ABSTRACT The susceptible parent FR1141, the resistant parent 061, the F1 cross, and 301 families selfed once from backcrosses to the susceptible parent were evaluated for gray leaf spot (GLS) severity for two years in Urbana, IL, and one year in Andrews, NC. Linkage between ear height and GLS severity was suspected. Th... | 18,944,528 |
Early Events During Quiescent Infection Development by Colletotrichum gloeosporioides in Unripe Avocado Fruits. | Inoculation of avocado pericarp tissue with Colletotrichum gloeospori-oides and treatment of avocado cell cultures with the cell wall elicitor of C. gloeosporioidesboth increased the production of reactive oxygen species (ROS). However, whereas the production of ROS could be detected within minutes in avocado cell susp... | 18,944,563 |
Bacterial-Mediated Induced Resistance in Cucumber: Beneficial Effect of the Endophytic Bacterium Serratia plymuthica on the Protection Against Infection by Pythium ultimum. | ABSTRACT The potential of the endophytic bacterium Serratia plymuthica strain R1GC4 in stimulating defense reactions in cucumber (Cucumis sativus) seedlings inoculated with the soilborne pathogen Pythium ultimum was explored at the cellular level. Bacterial treatment prior to Pythium inoculation resulted in less seedli... | 18,944,571 |
The Role of Chitinase Production by Stenotrophomonas maltophilia Strain C3 in Biological Control of Bipolaris sorokiniana. | ABSTRACT The role of chitinase production by Stenotrophomonas maltophilia strain C3 in biological control of leaf spot on tall fescue (Festuca arundinacea), caused by Bipolaris sorokiniana, was investigated in vitro and in vivo. The filtrate of a broth culture of C3, with chitin as the carbon source, was separated into... | 18,944,588 |
Genetic Differentiation and Host Specificity Among Populations of Alternaria spp. Causing Brown Spot of Grapefruit and Tangerine x Grapefruit Hybrids in Florida. | ABSTRACT Alternaria spp. were sampled from brown spot lesions in several geographically separated citrus groves and different grapefruit and tangerine x grapefruit hybrid cultivars in Florida and screened for variation at 16 putative random amplified polymorphic DNA loci. Populations of the pathogen on two hybrids, Min... | 18,944,592 |
Early brown rot infections in sweet cherry fruit are detected by monilinia-specific DNA primers. | ABSTRACT Visible and nonvisible quiescent infections of immature and mature fruit are an integral component of the disease cycle of brown rot of sweet cherry in California. Detection of these infections is critical for developing efficient and efficacious fungicide management programs. The previously published DNA ampl... | 18,944,605 |
Molecular Variability Among Isolates of Prunus Necrotic Ringspot Virus from Different Prunus spp. | ABSTRACT Viral sequences amplified by polymerase chain reaction from 25 isolates of Prunus necrotic ringspot virus (PNRSV), varying in the symptomatology they cause in six different Prunus spp., were analyzed for restriction fragment polymorphisms. Most of the isolates could be discriminated by using a combination of t... | 18,944,653 |
Chromosomal Gene Transfer by Conjugation in the Plant Pathogen Xanthomonas axonopodis pv. vesicatoria. | ABSTRACT Genes for copper resistance, located on the chromosome of strain XvP26 of Xanthomonas axonopodis pv. vesicatoria, were transferred by conjugation to a recipient strain of the bacterium. The chromosomal gene transfer was verified by analyses of the genomes of donor, recipient, and putative transconjugants for p... | 18,944,660 |
Identification of Subpopulations of Colletotrichum acutatum and Epidemiology of Almond Anthracnose in California. | ABSTRACT In recent years, almond anthracnose has developed into a major problem for the California almond industry. The identification of the causal pathogen as Colletotrichum acutatum was confirmed using species-specific primers and restriction fragment length polymorphisms of ribosomal DNA in comparative studies with... | 18,944,662 |
Microbial Antagonism at the Root Level Is Involved in the Suppression of Fusarium Wilt by the Combination of Nonpathogenic Fusarium oxysporum Fo47 and Pseudomonas putida WCS358. | ABSTRACT Two biological control agents, nonpathogenic Fusarium oxysporum Fo47 and Pseudomonas putida WCS358, were evaluated for suppression of Fusarium wilt of flax grown in nutrient solution and for suppression of the population density and metabolic activity of the causal organism F. oxysporum f. sp. lini strain Foln... | 18,944,664 |
Sampling in seed health testing. | ABSTRACT Seed health tests are usually performed on a sample of a seed lot; therefore, it is crucial that the test sample be as homogeneous as possible and representative of the lot. Seed sampling procedures appropriate for seed health testing have been developed by seed testing organizations such as the International ... | 18,944,666 |
Effects of Temperature and Wetness Duration on Infection of Peanut Cultivars by Cercospora arachidicola. | ABSTRACT The effects of temperature and duration of wetness (relative humidity >/=95%) on infection of three peanut cultivars by Cercospora arachidicola were determined under controlled conditions. Plants of the Spanish cv. Spanco and the runner cvs. Florunner and Okrun were exposed to constant temperatures of 18 to... | 18,944,677 |
Evaluation of Maize Streak Virus Pathogenicity in Differentially Resistant Zea mays Genotypes. | ABSTRACT We devised a rapid technique for the objective and precise assessment of both the pathogenicity of maize streak virus (MSV) isolates and the MSV resistance of maize genotypes. The technique involves the use of agroinoculation to infect maize seedlings and the objective symptom evaluation by quantification of i... | 18,944,683 |
Cytology of Infection of Maize Seedlings by Fusarium moniliforme and Immunolocalization of the Pathogenesis-Related PRms Protein. | ABSTRACT We have investigated the histology of infection of maize seedlings by Fusarium moniliforme in association with a biochemical host defense response, the accumulation of the PRms (pathogenesis-related maize seed) protein. Light microscopy of trypan blue-stained sections and scanning electron microscopy revealed ... | 18,944,701 |
Survey Methods for Assessment of Citrus Tristeza Virus Incidence When Toxoptera citricida Is the Predominant Vector. | ABSTRACT Citrus tristeza virus (CTV) incidence may be assessed by sampling groups of citrus trees, recording the groups as CTV positive (one or more infected trees) or CTV negative (no infected trees), and then calculating disease incidence at the scale of the individual tree by means of a formula involving incidence a... | 18,944,721 |
A Corn Trypsin Inhibitor with Antifungal Activity Inhibits Aspergillus flavus alpha-Amylase. | ABSTRACT In this study, we found that the inhibition of fungal growth in potato dextrose broth (PDB) medium by the 14-kDa corn trypsin inhibitor (TI) protein, previously found to be associated with host resistance to aflatoxin production and active against various fungi, was relieved when exogenous alpha-amylase was ad... | 18,944,733 |
Amy1, the alpha-Amylase Gene of Aspergillus flavus: Involvement in Aflatoxin Biosynthesis in Maize Kernels. | ABSTRACT Aspergillus flavus is the causal agent of an ear and kernel rot in maize. In this study, we characterized an alpha-amylase-deficient mutant and assessed its ability to infect and produce aflatoxin in wounded maize kernels. The alpha-amylase gene Amy1 was isolated from A. flavus, and its DNA sequence was determ... | 18,944,734 |
Evidence of Cytoplasmic Inheritance of Virulence in Cronartium ribicola to Major Gene Resistance in Sugar Pine. | ABSTRACT Tests for Mendelian segregation of virulence and avirulence in Cronartium ribicola, causal agent of white pine blister rust, to a major gene (R) for resistance in sugar pine were made using haploid basidiospore progenies from single diploid telia as inoculum on resistant genotypes. The telia were sampled from ... | 18,944,758 |
Biotrophic Development of Sporisorium reilianum f. sp. zeae in Vegetative Shoot Apex of Maize. | ABSTRACT Sporisorium reilianum f. sp. zeae is the causal agent of maize head smut, a disease present in several regions of France. A cytological study was carried out to describe a key step of the fungal etiology, in which the mycelium invades the vegetative shoot apex. Light and transmission electron microscopy observ... | 18,944,766 |
Molecular Identification and Phylogenetic Grouping of Diaporthe phaseolorum and Phomopsis longicolla Isolates from Soybean. | ABSTRACT Diaporthe phaseolorum and Phomopsis longicolla isolates from soybean were examined using traditional mycological characteristics and molecular methods. Cultural characteristics including types of fruiting bodies and conidia were assessed for isolates collected from soybean stems and seeds. Cultures were identi... | 18,944,833 |
Phytoplasma: ecology and genomic diversity. | ABSTRACT The recent development of molecular-based probes such as mono- and polyclonal antibodies, cloned phytoplasma DNA fragments, and phytoplasma-specific primers for polymerase chain reaction (PCR) has allowed for advances in detection and identification of uncultured phytoplasmas (formerly called mycoplasma-like o... | 18,944,840 |
The importance of archival and herbarium materials in understanding the role of oospores in late blight epidemics of the past. | ABSTRACT Nineteenth and early twentieth century botanists and mycologists collected healthy and infected plant materials from many regions of the world. Some of these plant collections preserved in herbaria around the world contain samples that are of considerable significance to epidemiologists, population biologists,... | 18,944,844 |
Unusual Cytoplasmic Inclusions Induced in Tobacco by Peanut Stunt Virus Subgroup II Strains Map to RNA3. | ABSTRACT Infection of tobacco protoplasts or leaf tissues with peanut stunt virus (PSV) subgroup II strains induced the production of unusual cytoplasmic ribbon-like inclusions. The inclusion structures appeared as long, thin, densely staining sheets that were prevalent within the cytoplasm, accumulating most commonly ... | 18,944,853 |
Transmission of Pineapple Mealybug Wilt-Associated Virus by Two Species of Mealybug (Dysmicoccus spp.). | ABSTRACT Closterovirus-like particles associated with mealybug wilt of pineapple were acquired and transmitted by the pink pineapple mealybug, Dysmicoccus brevipes, and the gray pineapple mealybug, D. neobrevipes. Mealybugs acquired pineapple mealybug wilt-associated virus (PMWaV) from infected pineapple plants or deta... | 18,944,858 |
Phylogenetic relationships within the family potyviridae: wheat streak mosaic virus and brome streak mosaic virus are not members of the genus rymovirus. | ABSTRACT The complete nucleotide sequence of wheat streak mosaic virus (WSMV) has been determined based on complementary DNA clones derived from the 9,384-nucleotide (nt) RNA of the virus. The genome of WSMV has a 130-nt 5' leader and 149-nt 3'-untranslated region and is polyadenylated at the 3' end. WSMV RNA encodes a... | 18,944,883 |
Immunocytochemical Evidence that Secretion of Pectin Occurs During Gel (Gum) and Tylosis Formation in Trees. | ABSTRACT During gel (gum) formation in angiosperm trees, fibrillar material accumulated in protective layers of xylem parenchyma cells before being secreted across half-bordered pit membranes into vessel elements. Immunogold labeling demonstrated that this fibrillar material was mainly composed of partially esterified ... | 18,944,900 |
Establishment of Bacterial Antagonists of Erwinia amylovora on Pear and Apple Blossoms as Influenced by Inoculum Preparation. | The influence of inoculum preparation on the establishment of bacterial antagonists that suppress fire blight and Erwinia amylovora on blossoms was evaluated. Aqueous suspensions of Pseudomonas fluorescens A506, E. herbicola C9-1R, or E. amylovora 153N were prepared from cells harvested from the surface of an agar medi... | 18,944,901 |
Satellite RNA of cucumber mosaic cucumovirus spreads epidemically in natural populations of its helper virus. | ABSTRACT Three hundred thirty-eight isolates of cucumber mosaic cucumovirus (CMV), sampled from natural populations in six areas of Spain between 1989 and 1996, were screened for the presence of satellite RNA (satRNA). The frequency of CMV isolates with satRNA approached 1.00 in Valencia (east Spain) between 1990 and 1... | 18,944,903 |
Effects of a Cover Crop on Splash Dispersal of Colletotrichum acutatum Conidia. | ABSTRACT A rain simulator, with generated rains of 11 and 30 mm/h, was used to determine the effect of a cover crop or intercrop on the splash dispersal of Colletotrichum acutatum conidia. Dispersal through sudangrass, which can be used as a 'living mulch', was tested at two planting densities (140 or 280 kg/ha) and tw... | 18,944,906 |
Survival of Fusarium moniliforme, F. proliferatum, and F. subglutinans in Maize Stalk Residue. | ABSTRACT The roles of residue size and burial depth were assessed in the survival of Fusarium moniliforme, F. proliferatum, and F. subglutinans in maize stalk residue. Stalk pieces (small or large sizes) were soaked in a spore suspension of F. moniliforme, F. proliferatum, or F. subglutinans and placed in a field on th... | 18,944,908 |
Molecular Evidence of Distinct Introductions of the European Race of Gremmeniella abietina into North America. | ABSTRACT The presence of the European (EU) race of Gremmeniella abietina var. abietina, the causal agent of Scleroderris canker of conifers, was first reported in North America in 1975 in the northeastern United States and subsequently in southern Quebec and Newfoundland during the late 1970s, where it quickly became e... | 18,944,913 |
Colonization of Host Plants by the Fire Blight Pathogen Erwinia amylovora Marked with Genes for Bioluminescence and Fluorescence. | ABSTRACT To follow the movement of Erwinia amylovora in plant tissue without dissection, this bacterium was marked with either the lux operon from Vibrio fischeri or the gfp gene from the jellyfish Aequorea victoria, both carried on multicopy plasmids and expressed under the control of the lac promoter from Escherichia... | 18,944,920 |
Pathogenicity of Streptomyces scabies Mutants Altered in Thaxtomin A Production. | ABSTRACT To investigate the role of thaxtomin A in the pathogenicity of Streptomyces scabies, mutants altered in thaxtomin A production were obtained by N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. Mutants of S. scabies EF-35 could be differentiated according to levels of thaxtomin production. Mutants M1, M8, and ... | 18,944,924 |
Isolation, Characterization, and Distribution of a Biocontrol Fungus from Cysts of Heterodera glycines. | ABSTRACT Seventy-six populations of Heterodera glycines were collected from 33 counties in 10 states of the United States along the Mississippi and Missouri Rivers in 1992 and 1993. A sterile hyphomycete fungus of an unnamed taxon, designated ARF18 and shown to be a parasite of eggs of H. glycines, was isolated from eg... | 18,944,928 |
Cytochemical Investigation of the Antagonistic Interaction Between a Microsphaeropsis sp. (Isolate P130A) and Venturia inaequalis. | ABSTRACT In an attempt to better understand the mode of action of the antagonistic fungus Microsphaeropsis sp., the interaction between this fungus and Venturia inaequalis was studied, using both light and electron microscopy. Cytological observations indicated that the antagonistic interaction between the two fungi li... | 18,944,932 |
Comparison of ambisense m RNA of watermelon silver mottle virus with other tospoviruses. | ABSTRACT Double-stranded genomic RNAs (dsRNAs) extracted from Chenopodium quinoa infected with watermelon silver mottle virus (WSMV) were similar to those of tomato spotted wilt virus (TSWV, serogroup I) and impatiens necrotic spot virus (INSV, serogroup III), except that the S dsRNA of WSMV is 0.75 and 0.6 kbp longer ... | 18,944,959 |
Monoterpene and Phenolic Compound Concentrations in Water-Stressed Red Pine Inoculated with Sphaeropsis sapinea. | ABSTRACT Changes in monoterpene and phenolic compounds resulting from water stress and colonization by Sphaeropsis sapinea were examined for 9- and 11-year-old red pine trees in a plantation and 3-year-old seedlings in a growth chamber. Four treatments were assigned at random to individual trees in the field: no treatm... | 18,944,971 |
Molecular Evidence That Strain BV-15 of Peanut Stunt Cucumovirus Is a Reassortant Between Subgroup I and II Strains. | ABSTRACT In Northern hybridization assays, RNA1 of peanut stunt virus (PSV) strain BV-15 hybridized strongly with a cloned cDNA probe to RNA1 from strain PSV-W (subgroup II). Cloned probes to PSV-W RNA2 and RNA3, however, did not hybridize with the corresponding RNAs from strain BV-15. The complete nucleotide sequence ... | 18,944,976 |
Determinants of density- and frequency-dependent fitness in competing plant pathogens. | ABSTRACT Using mathematical models, we investigated how infection and sporulation characteristics of competing plant pathogens determine the density and frequency dependence of relative fitness. Two models, one for the infection stage and one for the sporulation stage of a pathogen's life cycle, describe reproductive o... | 18,944,998 |
Binding of Tomato Spotted Wilt Virus to a 94-kDa Thrips Protein. | ABSTRACT Using protein blot assays, a 94-kDa thrips protein was identified that exhibited specific binding to tomato spotted wilt virus (TSWV) particles. Renaturation of the 94-kDa protein, which is conserved among the two major vector species of TSWV, Frankliniella occidentalis and Thrips tabaci, was crucial for its v... | 18,945,001 |
Populations of Xylella fastidiosa in Plants Required for Transmission by an Efficient Vector. | ABSTRACT Xylella fastidiosa, a xylem-limited bacterium that causes Pierce's disease (PD) of grapevine and other diseases, is transmitted efficiently by xylem-feeding leafhoppers. Acquisition of a PD strain of X. fastidiosa by the blue-green sharpshooter (BGSS) from five plant host species-grapevine (Vitis vinifera), Hi... | 18,945,018 |
Comparison of lettuce diseases and yield under subsurface drip and furrow irrigation. | ABSTRACT Subsurface drip and furrow irrigation were compared on lettuce (Lactuca sativa) cvs. Salinas and Misty Day for yield and incidence and severity of three important diseases of lettuce in the Salinas Valley, CA. Experiments were conducted between 1993 and 1995 during the spring and fall seasons. The diseases exa... | 18,945,057 |
Clavibacter michiganensis subsp. Sepedonicus Elicits a Hypersensitive Response in Tobacco and Secretes Hypersensitive Response-Inducing Protein(s). | ABSTRACT Strains of Clavibacter michiganensis subsp. sepedonicus, causal agent of bacterial ring rot of potato, showed marked differences in virulence on host plants. When infiltrated into tobacco leaves, virulent strains caused a rapid localized necrotic response (within 24 to 48 h) characteristic of the hypersensitiv... | 18,945,088 |
Molecular mapping of resistance to blight in an interspecific cross in the genus castanea. | ABSTRACT A three-generation American chestnut x Chinese chestnut pedigree was used to construct a genetic linkage map for chestnut and to investigate the control of resistance to Endothia parasitica (chestnut blight fungus). DNA genotypes for 241 polymorphic markers (eight isozymes, 17 restriction fragment length polym... | 18,945,098 |
Comparison of Soil Receptivity to Thielaviopsis basicola, Aphanomyces euteiches, and Fusarium solani f. sp. pisi Causing Root Rot in Pea. | ABSTRACT Soil receptivity as a quantifiable characteristic ranging from conduciveness to suppressiveness to soilborne pea pathogens Thielaviopsis basicola and Aphanomyces euteiches was determined by analysis of differences in disease response curves obtained by artificial introduction of inoculum into natural field soi... | 18,945,109 |
Characterization of the Suppressiveness of Hairy Vetch-Amended Soils to Thielaviopsis basicola. | ABSTRACT Factor(s) involved in soil suppressiveness to Thielaviopsis basicola when hairy vetch was used as a green manure were studied in a cotton production system. Soil suppressiveness was assessed in vitro at hairy vetch amendment levels of 0, 0.25, and 0.75% (wt/wt) by observing chlamydospores, using a nylon fabric... | 18,945,142 |
Epidemiological effect of gene deployment strategies on bacterial blight of rice. | ABSTRACT Experiments were conducted in farmers' fields at two locations of the irrigated lowlands of Laguna province in southern Luzon island, Philippines, during the wet seasons of 1993 and 1994. Nine rice populations were studied including pure stands, two-component mixtures, two-gene combinations of backcrossed line... | 18,945,155 |
Treatment with the Mycoparasite Pythium oligandrum Triggers Induction of Defense-Related Reactions in Tomato Roots When Challenged with Fusarium oxysporum f. sp. radicis-lycopersici. | ABSTRACT The influence exerted by the mycoparasite Pythium oligandrum in triggering plant defense reactions was investigated using an experimental system in which tomato plants were infected with the crown and root rot pathogen Fusarium oxysporum f. sp. radicis-lycopersici. To assess the antagonistic potential of P. ol... | 18,945,162 |
Spatial Patterns of Microsclerotia of Verticillium dahliae in Soil and Verticillium Wilt of Cauliflower. | ABSTRACT The spatial patterns of microsclerotia of Verticillium dahliae in soil and wilt symptoms on cauliflower were determined at three sites in each of two fields in 1994 and 1995. Each site was an 8 x 8 grid divided into 64 contiguous quadrats (2 by 2 m each). Soil samples were collected to a depth of 15 cm with a ... | 18,945,176 |
Ultrastructural and Cytochemical Investigations of the Antagonistic Effect of Verticillium lecanii on Cucumber Powdery Mildew. | ABSTRACT Chronological events of the intercellular interaction between Verticillium lecanii and cucumber powdery mildew, caused by Sphaerotheca fuliginea, were investigated at different times after inoculation by transmission electron microscopy. V. lecanii hyphae colonized host structures by tight binding, apparently ... | 18,945,181 |
Detection of a novel Francisella in Dermacentor reticulatus: a need for careful evaluation of PCR-based identification of Francisella tularensis in Eurasian ticks. | Francisella tularensis, the causative agent of tularemia, has been detected in ixodid ticks in some regions of North America, Europe, and Asia. In the present study, 245 Dermacentor reticulatus, 211 Ixodes ricinus, and 194 Haemaphysalis concinna adults from Hungary were tested for the presence of F. tularensis by polym... | 18,945,184 |
Community participation and the emergence of late-life depressive symptoms: differences between women and men. | To understand the role of community participation in prevention of first lifetime depressive episode in older women and men. We used data from the Wisconsin Longitudinal Study to identify variables that predicted risk for the emergence of depressive symptoms and tested a hypothesis that community participation would pr... | 18,945,207 |
Reactivity of nitric oxide with the [4Fe-4S] cluster of dihydroxyacid dehydratase from Escherichia coli. | Although the NO (nitric oxide)-mediated modification of iron-sulfur proteins has been well-documented in bacteria and mammalian cells, specific reactivity of NO with iron-sulfur proteins still remains elusive. In the present study, we report the first kinetic characterization of the reaction between NO and iron-sulfur ... | 18,945,212 |
Oxidized and poorly glycosylated band 3 is selectively phosphorylated by Syk kinase to form large membrane clusters in normal and G6PD-deficient red blood cells. | Oxidative events involving band 3 (Anion Exchanger 1) have been associated with RBC (red blood cell) removal through binding of NAbs (naturally occurring antibodies); however, the underlying mechanism has been only partially characterized. In addition to inducing direct membrane protein oxidative modification, oxidativ... | 18,945,214 |
Different bispectral index values from both sides of the forehead in unilateral carotid artery stenosis. | Bispectral index (BIS) values derived from the left and right forehead are usually the same. We report on two patients with unilateral carotid artery stenosis in whom we observed differences between the BIS values obtained from sensors placed on each side of the forehead. During surgery, the BIS values of the diseased ... | 18,945,245 |
Fluid therapy and the use of albumin in the treatment of severe traumatic brain injury. | Evidence-based guidelines for severe traumatic brain injury (TBI) do not include strategies for fluid administration. The protocol used in this study includes albumin administration to maintain normal colloid osmotic pressure and advocates a neutral to slightly negative fluid balance. The aim of this study was to analy... | 18,945,246 |
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