| cloning and sequence analysis of the eburicol 14alpha-demethylase gene of the obligate biotrophic grape powdery mildew fungus. | in order to obtain molecular data concerning field resistance of uncinula necator, the causal agent of grape powdery mildew, to sterol demethylation inhibitors, a major group of fungicides, the gene encoding the target of these compounds (eburicol 14alpha-demethylase) was cloned and sequenced from this obligately biotrophic phytopathogenic fungus. this single-copy gene encodes a 524 amino acid protein which displays high similarity to other known sterol 14alpha-demethylases (cyp51s). the coding ... | 1997 | 9300816 |
| rapid isolation of both double-stranded rna and pcr-suitable dna from the obligate biotrophic phytopathogenic fungus uncinula necator using a commercially available reagent. | a method for rapid extraction of both double-stranded rna (dsrna) and dna from an obligate biotrophic phytopathogenic fungus is described. lyophilised fungal material is incubated in a commercial guanidium thiocyanate reagent. proteins and cell debris are centrifuged by chloroform precipitation. after precipitation in isopropanol and washing in 75% ethanol, nucleic acids are resuspended in water (10 microl/mg fungal dry weight). dsrna is directly visualised by agarose gel electrophoresis. dna co ... | 1998 | 9779614 |
| identification of two different 14-alpha sterol demethylase-related genes (cyp51a and cyp51b) in aspergillus fumigatus and other aspergillus species. | two cyp51-related genes (cyp51a and cyp51b) encoding 14-alpha sterol demethylase-like enzymes were identified in the opportunistic human pathogen aspergillus fumigatus. pcr amplification using degenerate oligonucleotides based on conserved areas of cytochrome p450 demethylases of other filamentous fungi and yeasts allowed the cloning and sequencing of two different homologue genes in a. fumigatus. southern analysis confirmed that both genes hybridized to distinct genomic loci and that both are r ... | 2001 | 11427550 |
| laminarin elicits defense responses in grapevine and induces protection against botrytis cinerea and plasmopara viticola. | grapevine (vitis vinifera l.) is susceptible to many pathogens, such as botrytis cinerea, plasmopara viticola, uncinula necator, and eutypa lata. phytochemicals are used intensively in vineyards to limit pathogen infections, but the appearance of pesticide-resistant pathogen strains and a desire to protect the environment require that alternative strategies be found. in the present study, the beta-1,3-glucan laminarin derived from the brown algae laminaria digitata was shown both to be an effici ... | 2003 | 14651345 |
| transgenic plants of vitis vinifera cv. seyval blanc. | leaf discs of grapevine cv. seyval blanc originating from in vitro cultures were transformed with agrobacterium tumefaciens strain lba 4404 harbouring the vector pgj42 carrying genes for chitinase and rip (ribosome-inactivating protein) in an attempt to improve fungal resistance. the gene for neomycin phosphotransferase ii (nptii) was used as the selectable marker gene. the explants were cocultivated for 2 days with recombinant agrobacteria and then submitted to selection on nn69 medium containi ... | 2005 | 15812658 |
| evaluation of transgenic 'chardonnay' (vitis vinifera) containing magainin genes for resistance to crown gall and powdery mildew. | magainins, short peptides with broad-spectrum antimicrobial activity in vitro, were assayed for their ability to confer resistance to pathogens in transgenic grapevines. embryogenic cell suspensions of 'chardonnay' (vitis vinifera l.) were co-transformed by microprojectile bombardment with a plasmid carrying the npt-ii gene and a second plasmid harboring either a natural magainin-2 (mag2) or a synthetic derivative (msi99) gene. magainin genes and the marker gene were driven by arabidopsis ubiqui ... | 2006 | 16475011 |
| detection and quantification of erysiphe necator dna in wine grapes and resultant must and juice. | powdery mildew of grapevines is difficult to assess visually at the weighbridge, particularly in large consignments of machine-harvested fruit. to facilitate accurate methods for the detection and quantification of the disease in grape samples obtained from both the vineyard and winery, we developed a dna probe for the pathogen erysiphe necator. the e. necator-specific 450 bp dna fragment pena1, targets highly repetitive sequences and was isolated from a partial genomic library. in screening for ... | 2006 | 17010594 |
| cdna cloning and characterization of the novel genes related to aldehyde dehydrogenase from wild chinese grape (vitis pseudoreticulata w. t. wang). | mrna differential display was employed to study the gene differential expression of wild chinese grape (vitis pseudoreticulata w. t. wang) infected by uncinula necator in different periods, a cdna fragment of t11ac/b0319-456 coded by aldehyde dehydrogenase (aldh) gene has been obtained. 5' race and 3' race have been used to clone the whole cdna sequences of aldh which consists of three cdna sequences, whose sizes are 1887, 1956 and 1961 bp, and they encoded a polypeptide size of 537, 524 and 477 ... | 2007 | 17364808 |
| effect of carbendazim and physicochemical factors on the growth and ochratoxin a production of aspergillus carbonarius isolated from grapes. | carbendazim is a systemic fungicide that is commonly used on several crops (tobacco, fruit, vegetables, cereals, etc.). this fungicide is used to control fungal infections in vineyards. it is indicated against botrytis cinerea, uncinula necator, plasmopara viticola and other fungi and can be used either alone or coupled with other fungicides. however, there is a lack of in-depth studies to evaluate its effectiveness against growth of aspergillus carbonarius isolated from grapes and ota productio ... | 2007 | 17765991 |
| induction of a grapevine germin-like protein (vvglp3) gene is closely linked to the site of erysiphe necator infection: a possible role in defense? | germin-like proteins (glp) have various proposed roles in plant development and defense. seven novel glp cdna clones were isolated from grapevine (vitis vinifera cv. chardonnay). reverse transcriptase-polymerase chain reaction expression analysis revealed that the vvglp genes exhibit diverse and highly specific patterns of expression in response to a variety of abiotic and biotic treatments, including challenge by erysiphe necator, plasmopara viticola, and botrytis cinerea, suggesting a diversit ... | 2007 | 17849714 |
| powdery mildew induces defense-oriented reprogramming of the transcriptome in a susceptible but not in a resistant grapevine. | grapevines exhibit a wide spectrum of resistance to the powdery mildew fungus (pm), erysiphe necator (schw.) burr., but little is known about the transcriptional basis of the defense to pm. our microscopic observations showed that pm produced less hyphal growth and induced more brown-colored epidermal cells on leaves of pm-resistant vitis aestivalis 'norton' than on leaves of pm-susceptible vitis vinifera 'cabernet sauvignon'. we found that endogenous salicylic acid levels were higher in v. aest ... | 2008 | 17993546 |
| resistance to erysiphe necator in the grapevine 'kishmish vatkana' is controlled by a single locus through restriction of hyphal growth. | vitis vinifera 'kishmish vatkana', a cultivated grapevine from central asia, does not produce visible symptoms in response to natural or artificial inoculation with the fungus erysiphe necator schwein., the casual agent of powdery mildew. 'kishmish vatkana' allowed pathogen entry into epidermal cells at a rate comparable to that in the susceptible control vitis vinifera 'nimrang', but was able to limit subsequent hyphal proliferation. density of conidiophores was significantly lower in 'kishmish ... | 2008 | 18064436 |
| genetic structure and aggressiveness of erysiphe necator populations during grapevine powdery mildew epidemics. | isolates of the causal ascomycete of grapevine powdery mildew, erysiphe necator, correspond to two genetically differentiated groups (a and b) that coexist on the same host. this coexistence was analyzed by investigating temporal changes in the genetic and phenotypic structures of e. necator populations during three epidemics. group a was present only at the start of the growing season, whereas group b was present throughout all three epidemics. group a was less aggressive in terms of germinatio ... | 2008 | 18723657 |
| ontogenic resistance to powdery mildew in grape berries. | abstract berries of vitis vinifera are reported to be susceptible to infection by uncinula necator until soluble solids levels (brix) reach 8%, and established colonies are reported to sporulate until brix reach 15%. however, our analysis of disease progress on fruit of selected v. vinifera cultivars indicated that severity became asymptotic several weeks earlier in fruit development. when mildew-free fruit clusters of v. vinifera 'chardonnay', 'riesling', 'gewürztraminer', and 'pinot noir' were ... | 2003 | 18942976 |
| effects of ontogenic resistance upon establishment and growth of uncinula necator on grape berries. | abstract grape berries become resistant to powdery mildew early in development and are nearly immune to infection within 4 weeks after bloom. in this study, ontogenic resistance did not reduce attachment, germination, or appressorium formation of uncinula necator on 3- to 4-week-old berries of vitis vinifera 'chardonnay' or 3-week-old berries of v. labruscana 'concord'. pathogen ingress halted at the cuticle before formation of a penetration pore. as berries aged, hyphal elongation and colony gr ... | 2003 | 18942977 |
| osmotin and thaumatin from grape: a putative general defense mechanism against pathogenic fungi. | abstract little information is available concerning the expression of pathogenesis-related (pr) proteins in grapevine (vitis vinifera) and their effect properties on the major fungal pathogens of grape. a systematic study was performed on the effect of total or individual grape proteins on mycelial growth, spore germination, and germ tube growth of uncinula necator, phomopsis viticola, and botrytis cinerea. two proteins, identified as pr proteins by immunological methods and by n-terminal sequen ... | 2003 | 18943614 |
| effects of diffuse colonization of grape berries by uncinula necator on bunch rots, berry microflora, and juice and wine quality. | abstract production of grape (principally cultivars of vitis vinifera) for high-quality wines requires a high level of suppression of powdery mildew (uncinula necator syn. erysiphe necator). severe infection of either fruit or foliage has well-documented and deleterious effects upon crop and wine quality. we found that berries nearly immune to infection by u. necator due to the development of ontogenic resistance may still support diffuse and inconspicuous mildew colonies when inoculated approxi ... | 2007 | 18943695 |
| the epidemiology of powdery mildew on concord grapes. | abstract vitis labruscana 'concord' is a grape cultivar widely grown in the united states for processing into juice and other grape products. concord grapes are sporadically but sometimes severely damaged by the grape powdery mildew pathogen, uncinula necator. although the foliage is often reported to be moderately resistant to powdery mildew, severe fruit infection occurs in some years. we observed the seasonal development of powdery mildew on leaves, rachises, and berries of unsprayed concord ... | 2001 | 18944121 |
| up-regulated transcripts in a compatible powdery mildew-grapevine interaction. | powdery mildews (erysiphales) are obligate biotrophic pathogens that invade susceptible plant cells without triggering cell death. this suggests a highly adept mechanism of parasitism which enables powdery mildews to avoid detection or evade defenses by their host. to better understand this plant-pathogen interaction, we employed suppression subtractive hybridization (ssh), differential hybridization and quantitative real-time (qrt) pcr for the identification of grapevine (vitis vinifera l.) gen ... | 2009 | 19362490 |
| characterization of a novel stilbene synthase promoter involved in pathogen- and stress-inducible expression from chinese wild vitis pseudoreticulata. | stilbene synthase is a plant-specific polyketide synthase, and plays important roles in diverse metabolic processes. the genomic stilbene synthase gene was cloned from accession "baihe-35-1" of chinese wild vitis pseudoreticulata, and a stilbene synthase of v. pseudoreticulata (vpsts) transcripts expressed in the grape-powdery mildew interaction were determined by semi-quantitative rt-pcr. to monitor vpsts expression in plant, the promoter region flanking the 5' vpsts coding region was isolated ... | 2010 | 19937257 |
| the powdery mildew resistance gene ren1 co-segregates with an nbs-lrr gene cluster in two central asian grapevines. | grape powdery mildew is caused by the north american native pathogen erysiphe necator. eurasian vitis vinifera varieties were all believed to be susceptible. ren1 is the first resistance gene naturally found in cultivated plants of vitis vinifera. | 2009 | 20042081 |
| a functional eds1 ortholog is differentially regulated in powdery mildew resistant and susceptible grapevines and complements an arabidopsis eds1 mutant. | vitis vinifera (grapevine) is the most economically important deciduous fruit crop, but cultivated grapevine varieties lack adequate innate immunity to a range of devastating diseases. to identify genetic resources for grapevine innate immunity and understand pathogen defense pathways in a woody perennial plant, we focus in this study on orthologs of the central arabidopsis thaliana defense regulator enhanced disease susceptibility1 (eds1). the family of eds1-like genes is expanded in grapevine, ... | 2010 | 20145949 |
| occurrence of erysiphe necator chasmothecia and their natural parasitism by ampelomyces quisqualis. | in northern italy, erysiphe necator overwinters almost exclusively as chasmothecia. from 2004 to 2008, we investigated the occurrence of natural parasitism of grapevine powdery mildew chasmothecia by ampelomyces quisqualis in the trentino-alto adige region, in northern italy. the survey was conducted in 18 vineyards in autumn 2004 and 2005 and in 45 vineyards in autumn 2006 and 2007. the incidence of powdery mildew signs (white powdery mycelia and conidia), the number of chasmothecia and their d ... | 2009 | 19453229 |
| changes in protein abundance during powdery mildew infection of leaf tissues of cabernet sauvignon grapevine (vitis vinifera l.). | a comparative analysis of differentially expressed proteins in a susceptible grapevine (vitis vinifera 'cabernet sauvignon') during the infection of erysiphe necator, the causal pathogen of grapevine powdery mildew (pm), was conducted using itraq. the quantitative labeling analysis revealed 63 proteins that significantly changed in abundance at 24, 36, 48, and 72 h post inoculation with powdery mildew conidiospores. the functional classification of the pm-responsive proteins showed that they are ... | 2010 | 20232356 |
| baseline sensitivity to proquinazid in blumeria graminis f. sp. tritici and erysiphe necator and cross-resistance with other fungicides. | proquinazid is a new quinazolinone fungicide from dupont registered in most european countries for powdery mildew control in cereals and vines. the aim of this paper is to present baseline sensitivity data in populations of blumeria graminis f. sp. tritici em marchal and erysiphe necator (schw) burr as well as results from cross-resistance studies with other fungicides. | 2009 | 19418441 |
| rapd analysis provides insight into the biology and epidemiology of uncinula necator. | abstract ninety isolates of grape powdery mildew (uncinula necator) from europe (sixty-two) and india (twenty-eight) were collected. ten of the sixty-two european isolates originated from mycelium overwintering in dormant buds ("flagshoots"). mating types were determined, and genetic variation was assessed by random amplified polymorphic dna (rapd). forty-one european isolates, including all "flagshoot" isolates, were mating type +, and twenty-one were mating type -. all indian isolates were mat ... | 1997 | 18945087 |
| pesticides' influence on wine fermentation. | wine quality strongly depends on the grape quality. to obtain high-quality wines, it is necessary to process healthy grapes at the correct ripeness stage and for this reason the farmer has to be especially careful in the prevention of parasite attacks on the grapevine. the most common fungal diseases affecting grape quality are downy and powdery mildew (plasmopara viticola and uncinula necator), and gray mold (botrytis cinerea). on the other hand, the most dangerous insects are the grape moth (l ... | 2010 | 20610173 |
| distributions of sensitivities to three sterol demethylation inhibitor fungicides among populations of uncinula necator sensitive and resistant to triadimefon. | abstract single-conidial isolates of uncinula necator from (i) a population representing two vineyards with no previous exposure to sterol demethylation inhibitor (dmi) fungicides ("unexposed," n = 77) and (ii) a population representing two vineyards in which powdery mildew was poorly controlled by triadimefon after prolonged dmi use ("selected," n = 82) were assayed to determine distributions of sensitivities to the dmi fungicides triadimenol (the active form of triadimefon), myclobutanil, and ... | 1997 | 18945045 |
| phylogeography and population structure of the grape powdery mildew fungus, erysiphe necator, from diverse vitis species. | the grape powdery mildew fungus, erysiphe necator, was introduced into europe more than 160 years ago and is now distributed everywhere that grapes are grown. to understand the invasion history of this pathogen we investigated the evolutionary relationships between introduced populations of europe, australia and the western united states (us) and populations in the eastern us, where e. necator is thought to be native. additionally, we tested the hypothesis that populations of e. necator in the e ... | 2010 | 20809968 |
| ontogenic resistance and plant disease management: a case study of grape powdery mildew. | abstract a fundamental principle of integrated pest management is that actions taken to manage disease should be commensurate with the risk of infection and loss. one of the less-studied factors that determines this risk is ontogenic, or age-related resistance of the host. ontogenic resistance may operate at the whole plant level or in specific organs or tissues. until recently, grape berries were thought to remain susceptible to powdery mildew (uncinula necator) until late in their development. ... | 2002 | 18944267 |
| effects of humidity on the development of grapevine powdery mildew. | abstract the effects of humidity on powdery mildew development on grape seedlings and the germination of uncinula necator conidia in vitro were examined. studies were conducted at an optimum temperature of 25 +/- 2 degrees c. disease on foliage was markedly affected by humidity levels in the test range of 39 to 98% relative humidity (rh), corresponding to vapor pressure deficits (vpd) of 1,914 to 61 pa. incidence and severity increased with increasing humidity to an optimum near 85% rh, and then ... | 2003 | 18944098 |
| host barriers and responses to uncinula necator in developing grape berries. | abstract grape berries are highly susceptible to powdery mildew 1 week after bloom but acquire ontogenic resistance 2 to 3 weeks later. we recently demonstrated that germinating conidia of the grape powdery mildew pathogen (uncinula necator) cease development before penetration of the cuticle on older resistant berries. the mechanism that halts u. necator at that particular stage was not known. several previous studies investigated potential host barriers or cell responses to powdery mildew in b ... | 2004 | 18943761 |
| detection of erysiphe necator in air samples using the polymerase chain reaction and species-specific primers. | abstract a polymerase chain reaction (pcr) assay employing species-specific primers was developed to differentiate erysiphe necator from other powdery mildews common in the northwest united states. dna was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a burkard cyclonic surface sampler. to differentiate e. necator from other erysiphaeceous fungi, primer pairs uncin144 and uncin511 were developed to select unique sequences of the internal transcri ... | 2007 | 18943687 |
| spatial and genetic analysis of a flag shoot subpopulation of erysiphe necator in italy. | abstract erysiphe necator overwinters as ascospores in cleistothecia and mycelium in dormant buds of grapevines. shoots developing from infected buds early in the growing season are covered with dense mycelium and are known as "flag shoots". combining epidemiological and genetic analyses, the objective of this study was to analyze the spatial and genetic structure of a flag shoot subpopulation of e. necator as a way to assess the contribution of flag shoots as primary inoculum, and to determine ... | 2004 | 18943478 |
| persistence and spatial autocorrelation of clones of erysiphe necator overwintering as mycelium in dormant buds in an isolated vineyard in northern italy. | the population structure of the grape powdery mildew fungus, erysiphe necator (formerly uncinula necator), has been hypothesized to vary from being clonal to highly diverse and recombining. we report here on the structure of an e. necator population sampled during a 4-year period from an isolated vineyard in northern italy (voghera, pavia province). we obtained 54 isolates of e. necator that overwintered asexually as mycelium in grapevine buds and caused severe symptoms on the emerging shoots, k ... | 2008 | 18943190 |
| ethephon elicits protection against erysiphe necator in grapevine. | the grapevine (vitis vinifera) is susceptible to many pathogens such as botrytis cinerea, plasmopara viticola, erysiphe necator, and eutypa lata. phytochemicals are used extensively in vineyards to reduce pathogen infections, but the appearance of pesticide-resistant pathogen strains and the need for environmental protection require the use of alternative strategies. the phytohormone ethylene is assumed to play a role in the development of disease resistance. in the present study, we have treate ... | 2008 | 18570435 |
| rationalization of pesticide treatments against powdery mildew of grape. | the powdery mildew represents one of the diseases which affect the grape, it is diffused in all agricultural regions with variable intensity and epidemic course in operation of many microclimatic factors. the powdery mildew of grape is caused from uncinala necator (schw.) burr. (nowadays named erysiphe necator schwein.); it is controlled with systemic therapy and contact chemical products. in some vineyards located in latium (central italy), different field trials have been carried out purposely ... | 2007 | 18399458 |
| mechanisms of powdery mildew resistance in the vitaceae family. | the cultivated grapevine, vitis vinifera, is a member of the vitaceae family, which comprises over 700 species in 14 genera. vitis vinifera is highly susceptible to the powdery mildew pathogen erysiphe necator. however, other species within the vitaceae family have been reported to show resistance to this fungal pathogen, but little is known about the mechanistic basis of this resistance. therefore, the frequency of successful e. necator penetration events, in addition to programmed cell death ( ... | 2010 | 21355998 |
| differential gene expression during conidiation in the grape powdery mildew pathogen, erysiphe necator. | asexual sporulation (conidiation) is coordinately regulated in the grape powdery mildew pathogen erysiphe necator but nothing is known about its genetic regulation. we hypothesized that genes required for conidiation in other fungi would be upregulated at conidiophore initiation or full conidiation (relative to preconidiation vegetative growth and development of mature ascocarps), and that the obligate biotrophic lifestyle of e. necator would necessitate some novel gene regulation. cdna amplifie ... | 2011 | 21405992 |
| impact of sulfur on density of tetranychus pacificus (acari: tetranychidae) and galendromus occidentalis (acari: phytoseiidae) in a central california vineyard. | sulfur is the oldest and most widely used fungicide in the vineyards of california, where it is used for control of powdery mildew (uncinula necator [schw.] burr). for decades, sulfur use has been associated with outbreaks of tetranychus pacificus mcgregor (acari: tetranychidae) on cultivated grapes in the san joaquin valley. i undertook large-scale field studies to test this association, to evaluate the impact of sulfur on galendromus occidentalis (nesbit) (acari: phytoseiidae), a major predato ... | 2007 | 17611804 |
| grapevine powdery mildew (erysiphe necator): a fascinating system for the study of the biology, ecology and epidemiology of an obligate biotroph. | few plant pathogens have had a more profound effect on the evolution of disease management than erysiphe necator, which causes grapevine powdery mildew. when the pathogen first spread from north america to england in 1845, and onwards to france in 1847, 'germ theory' was neither understood among the general populace nor even generally accepted within the scientific community. louis pasteur had only recently reported the microbial nature of fermentation, and it would be another 30 years before ro ... | 2011 | 21726395 |
| co-expression of vpromt gene from chinese wild vitis pseudoreticulata with vpsts in tobacco plants and its effects on the accumulation of pterostilbene. | plant secondary metabolites, such as stilbenes, have fungicidal potential and have been found in several plant species. stilbenes in grapevine, such as resveratrol and pterostilbene, have recently attracted much attention, they are not only helping the plant to fight against pathogen attack, but they are also being widely used as ingredients of fungicide, anti-inflammatory drugs, antioxidant, and anti-infective agents. however, resveratrol o-methyltransferase gene, related with the synthesis of ... | 2011 | 22038118 |
| methyl jasmonate induces defense responses in grapevine and triggers protection against erysiphe necator. | grapevine is subject to a number of diseases that affect yield and wine quality. to limit the excessive use of phytochemicals in the vineyard, alternative strategies have to be developed. plant treatment with signaling molecules like elicitors stimulates their natural defense mechanisms. to improve grapevine tolerance against fungal pathogens, vitis vinifera plants were treated with a natural exogenous elicitor, methyl jasmonate (meja). meja-treated leaves (cabernet sauvignon foliar cuttings) re ... | 2006 | 17117799 |
| cdna clone, fusion expression and purification of the novel gene related to ascorbate peroxidase from chinese wild vitis pseudoreticulata in e. coli. | powdery mildew, caused by uncinula necator burr, is one of the most seriously damaging diseases of grapevine all over the world. to gain the novel gene and investigate the resistance mechanism in chinese wild vitis pseudoreticulata clone baihe-35-1, mrna differential display was employed to study the differential expression of the resistant gene to the disease of it when inoculated by uncinula necator under natural field conditions, 5' race and 3' race have been used to clone the whole cdna sequ ... | 2006 | 16850189 |
| sensitivity of uncinula necator to quinoxyfen: evaluation of isolates selected using a discriminatory dose screen. | quinoxyfen is a protectant fungicide that provides excellent control of many powdery mildew diseases. prior to the launch of quinoxyfen in vines in 1998, a leaf disc sporulation assay was developed to assess the sensitivity of uncinula necator (schw) burr to quinoxyfen. the distribution of ec(50) values from 56 monoconidial u. necator isolates collected from six countries between 1993 and 1996 was found to range from less than 0.03 to 2.6 mg litre(-1). although this range of ec(50) values was qu ... | 2006 | 16612812 |
| genetic similarity of flag shoot and ascospore subpopulations of erysiphe necator in italy. | the overwintering mode of the grape powdery mildew fungus, erysiphe necator (syn. uncinula necator), as mycelium in dormant buds (resulting in symptoms known as flag shoots) or as ascospores in cleistothecia, affects the temporal dynamics of epidemics early in the growing season. we tested whether distinct genetic groups (i and iii) identified previously in e. necator correlate to overwintering modes in two vineyards in tuscany, italy, to determine whether diagnostic genetic markers could be use ... | 2005 | 16332752 |
| quantitative trait locus analysis of fungal disease resistance factors on a molecular map of grapevine. | a full-sibling f1 population comprising 153 individuals from the cross of 'regent' x 'lemberger' was employed to construct a genetic map based on 429 molecular markers. the newly-bred red grapevine variety 'regent' has multiple field-resistance to fungal diseases inherited as polygenic traits, while 'lemberger' is a traditional fungus-susceptible cultivar. the progeny segregate quantitatively for resistances to plasmopara viticola and uncinula necator, fungal pathogens that threaten viticulture ... | 2004 | 14574452 |
| impact odorants contributing to the fungus type aroma from grape berries contaminated by powdery mildew (uncinula necator); incidence of enzymatic activities of the yeast saccharomyces cerevisiae. | powdery mildew due to the fungus uncinula necator is an important disease for the vineyard. the development of the fungus at the surface of the berries leads to the occurrence of a very characteristic and sometimes intense mushroom-type odor cited as an important default for grapes quality. gas chromatography/olfactometry, gas chromatography, and multidimensional gas chromatogaphy/mass spectrometry techniques were used to investigate the most important odorants of grapes diseased by powdery mild ... | 2002 | 12009998 |
| fate of quinoxyfen residues in grapes, wine, and their processing products. | quinoxyfen is a new fungicide that belongs to the family of the quinolines, recently introduced to control powdery mildew (uncinula necator). in this paper the fate of quinoxyfen residues from vine to wine and in their processing products was studied. after the last of four applications at the recommended rate, 0.38 mg/kg of residue was found on the grapes, which is under the legal limit fixed in italy (0.5 mg/kg). the degradation rate was according to a pseudo-first-order kinetics (r = 0.964) a ... | 2000 | 11312786 |
| nested allele-specific pcr primers distinguish genetic groups of uncinula necator. | isolates of the obligately biotrophic fungus uncinula necator cluster in three distinct genetic groups (groups i, ii, and iii). we designed pcr primers specific for these groups in order to monitor field populations of u. necator. we used the nucleotide sequences of the gene that encodes eburicol 14alpha-demethylase (cyp51) and of the ribosomal dna internal transcribed spacer 1 (its1), its2, and 5. 8s regions. we identified four point mutations (three in cyp51 and one in its1) that distinguished ... | 1999 | 10473400 |
| a mutation in the 14 alpha-demethylase gene of uncinula necator that correlates with resistance to a sterol biosynthesis inhibitor. | we investigated the molecular basis of resistance of the obligate biotrophic grape powdery mildew fungus uncinula necator to sterol demethylation-inhibiting fungicides (dmis). the sensitivity of 91 single-spore field isolates of u. necator to triadimenol was assessed by using a leaf disc assay. resistance factors (rf) ranged from 1.8 to 26.0. the gene encoding the target of dmis (eburicol 14 alpha-demethylase) from five sensitive and seven resistant isolates was cloned and sequenced. a single mu ... | 1997 | 9251183 |
| identification and characterization of a fruit-specific, thaumatin-like protein that accumulates at very high levels in conjunction with the onset of sugar accumulation and berry softening in grapes. | the protein composition of the grape (vitis vinifera cv muscat of alexandria) berry was examined from flowering to ripeness by gel electrophoresis. a protein with an apparent molecular mass of 24 kd, which was one of the most abundant proteins in extracts of mature berries, was purified and identified by amino acid sequence to be a thaumatin-like protein. combined cdna sequence analysis and electrospray mass spectrometry revealed that this protein, vvtl1 (for v. vinifera thaumatin-like protein 1 ... | 1997 | 9232867 |
| biodiversity and new records of microfungi in the ruhrarea (north rhine westfalia), germany. | during our investigations of the microflora in nrw (duisburg, düsseldorf and essen incl. the greenhouse of the botanical garden) in 2007 and 2008, we were able to collect and identify about 55 species on trees, bushes and ornamental plants as parasites and saprophytes. some of these species are new for germany or have been only rarely found until now. most of the species belong the ascomycotina, basidiomycotina and deuteromycotina for example arthrocladiella mougeotii (lév.) vassilkov. on lycium ... | 2009 | 20222564 |
| a transcriptomic study of grapevine (vitis vinifera cv. cabernet-sauvignon) interaction with the vascular ascomycete fungus eutypa lata. | eutypa dieback is a vascular disease that may severely affect vineyards throughout the world. in the present work, microarrays were made in order (i) to improve our knowledge of grapevine (vitis vinifera cv. cabernet-sauvignon) responses to eutypa lata, the causal agent of eutypa dieback; and (ii) to identify genes that may prevent symptom development. qiagen/operon grapevine microarrays comprising 14,500 probes were used to compare, under three experimental conditions (in vitro, in the greenhou ... | 2010 | 20190040 |
| transient expression of glyoxal oxidase from the chinese wild grape vitis pseudoreticulata can suppress powdery mildew in a susceptible genotype. | vitis pseudoreticulata glyoxal oxidase (vpglox) was previously isolated from the chinese wild vine v. pseudoreticulata accession "baihe-35-1" during a screen for genes that are upregulated in response to infection with grapevine powdery mildew (erysiphe necator, pm). in the present study, a possible function of vpglox for defense against pm was investigated using agrobacterium-mediated transient expression. after optimizing agro-infiltration, vpglox was transiently overexpressed in leaves of eit ... | 2011 | 20512385 |
| evaluation of fungal and yeast diversity in slovakian wine-related microbial communities. | since the yeast flora of slovakian enology has not previously been investigated by culture-independent methods, this approach was applied to two most common cultivars frankovka (red wine) and veltlin (white wine), and complemented by cultivation. model samples included grapes, initial must, middle fermenting must and must in the end-fermentation phase. the cultured isolates were characterized by length polymorphism of rdna spacer two region using fluorescence pcr and capillary electrophoresis (f ... | 2010 | 20556654 |
| effects of acute low-temperature events on development of erysiphe necator and susceptibility of vitis vinifera. | growth and development of erysiphe necator (syn. uncinula necator) has been extensively studied under controlled conditions, primarily with a focus on development of grapevine powdery mildew within the optimal temperature range and the lethal effects of high temperatures. however, little is known of the effect of cold temperatures (above freezing but <8 degrees c) on pathogen development or host resistance. pretreatment of susceptible vitis vinifera leaf tissue by exposure to cold temperatures ( ... | 2010 | 20649419 |
| expression and functional analysis of two genes encoding transcription factors, vpwrky1 and vpwrky2, isolated from chinese wild vitis pseudoreticulata. | in this study, two wrky genes were isolated from erysiphe necator-resistant chinese wild vitis pseudoreticulata w. t. wang 'baihe-35-1', and designated as vpwrky1 (genbank accession no. gq884198) and vpwrky2 (genbank accession no. gu565706). nuclear localization of the two proteins was demonstrated in onion epidermal cells, while trans-activation function was confirmed in the leaves of 'baihe-35-1'. expression of vpwrky1 and vpwrky2 was induced rapidly by salicylic acid treatment in 'baihe-35-1' ... | 2010 | 20811906 |
| variation in pathogenicity and aggressiveness of erysiphe necator from different vitis spp. and geographic origins in the eastern united states. | eastern north america is considered the center of diversity for many vitis spp. and for the grape powdery mildew pathogen, erysiphe necator. however, little is known about populations of e. necator from wild vitis spp. we determined the phenotypic variation in pathogenicity and aggressiveness of e. necator among isolates from wild and domesticated vitis spp. from diverse geographic regions in the eastern united states. to test pathogenicity, we inoculated 38 e. necator isolates on three wild vit ... | 2010 | 20932167 |
| efficacy of fungicides with various modes of action in controlling the early stages of an erysiphe necator-induced epidemic. | limiting the use of fungicides is due to become an important issue in managing erysiphe necator (schwein) burrill infections in vineyards. the authors determined how three fungicides currently used by vine growers could be managed to control the early stages of an e. necator-induced epidemic. | 2010 | 20949548 |
| assessment of fungicide resistance and pathogen diversity in erysiphe necator using quantitative real-time pcr assays. | management of grapevine powdery mildew erysiphe necator schw. requires fungicide treatments such as sterol demethylation inhibitors (dmis) or mitochondrial inhibitors (qois). recently, reduction in the efficacy of dmis or qois was reported in europe and the united states. the aim of the present study was to develop real-time qpcr tools to detect and quantify several cyp51 gene variants of e. necator: (i) a versus b groups (g37a) and (ii) sensitive versus resistant to sterol demethylase inhibitor ... | 2010 | 20949585 |
| dynamics of ascospore maturation and discharge in erysiphe necator, the causal agent of grape powdery mildew. | dynamics of ascocarp development, ascospore maturation, and dispersal in erysiphe necator were studied over a 4-year period, from the time of ascocarp formation to the end of the ascosporic season at the end of june in the following spring. naturally dispersed chasmothecia were collected from mid-august to late november (when leaf fall was complete); the different collections were used to form three to five cohorts of chasmothecia per year, with each cohort containing ascocarps formed in differe ... | 2010 | 21062172 |
| a single dominant locus, ren4, confers rapid non-race-specific resistance to grapevine powdery mildew. | in the present study we screened the progeny of vitis vinifera × v. romanetii populations segregating for resistance to powdery mildew and determined the presence of a single, dominant locus, ren4, conferring rapid and extreme resistance to the grapevine powdery mildew fungus erysiphe necator. in each of nine ren4 pseudo-backcross 2 (pbc(2)) and pbc(3) populations (1,030 progeny), resistance fit a 1:1 segregation ratio and overall segregated as 543 resistant progeny to 487 susceptible. in full-s ... | 2011 | 21091183 |
| using a limited mapping strategy to identify major qtls for resistance to grapevine powdery mildew (erysiphe necator) and their use in marker-assisted breeding. | a limited genetic mapping strategy based on simple sequence repeat (ssr) marker data was used with five grape populations segregating for powdery mildew (erysiphe necator) resistance in an effort to develop genetic markers from multiple sources and enable the pyramiding of resistance loci. three populations derived their resistance from muscadinia rotundifolia 'magnolia'. the first population (06708) had 97 progeny and was screened with 137 ssr markers from seven chromosomes (4, 7, 9, 12, 13, 15 ... | 2010 | 21188350 |
| a bayesian approach to assessing the uncertainty in estimating bioconcentration factors in earthworms--the example of quinoxyfen. | quinoxyfen is a fungicide of the phenoxyquinoline class used to control powdery mildew, uncinula necator (schw.) burr. owing to its high persistence and strong sorption in soil, it could represent a risk for soil organisms if they are exposed at ecologically relevant concentrations. the objective of this paper is to predict the bioconcentration factors (bcfs) of quinoxyfen in earthworms, selected as a representative soil organism, and to assess the uncertainty in the estimation of this parameter ... | 2011 | 21337673 |
| identification and structure of the mating-type locus and development of pcr-based markers for mating type in powdery mildew fungi. | in ascomycetes, mating compatibility is regulated by the mating-type locus, mat1. the objectives of this study were to identify and sequence genes at the mat1 locus in the grape powdery mildew fungus, erysiphe necator, to develop a pcr-based marker for determining mating type in e. necator, and to develop degenerate primers for amplification by pcr of conserved regions of mating-type idiomorphs in other powdery mildew fungi. we identified mat1-2-1 of the mat1-2 idiomorph in e. necator based on t ... | 2011 | 21515399 |
| Identification of Race-Specific Resistance in North American Vitis spp. Limiting Erysiphe necator Hyphal Growth. | ABSTRACT Race-specific resistance against powdery mildews is well documented in small grains but, in other crops such as grapevine, controlled analysis of host-pathogen interactions on resistant plants is uncommon. In the current study, we attempted to confirm powdery mildew resistance phenotypes through vineyard, greenhouse, and in vitro inoculations for test cross-mapping populations for two resistance sources: (i) a complex hybrid breeding line, 'Bloodworth 81-107-11', of at least Vitis rot ... | 2012 | 22165984 |
| development of marker sets useful in the early selection of ren4 powdery mildew resistance and seedlessness for table and raisin grape breeding. | the single, dominant powdery mildew resistance locus ren4 from vitis romanetii prevents hyphal growth by erysiphe necator. previously, we showed that when introgressed into v. vinifera in the modified bc(2) population 03-3004, ren4 was linked with the simple sequence repeat marker vmc7f2 on chromosome 18-a marker that is associated with multiple disease resistance and seedlessness. however, in the current study, this marker was monomorphic in related breeding populations 05-3010 and 07-3553. to ... | 2011 | 21904846 |
| vprfp1, a novel c4c4-type ring finger protein gene from chinese wild vitis pseudoreticulata, functions as a transcriptional activator in defence response of grapevine. | ring finger proteins comprise a large family and play important roles in regulation of growth and development, hormone signalling, and responses to biotic and abiotic stresses in plants. in this study, the identification and functional characterization of a c4c4-type ring finger protein gene from the chinese wild grapevine vitis pseudoreticulata (designated vprfp1) are reported. vprfp1 was initially identified as an expressed sequence tag (est) from a cdna library constructed from leaves of v. p ... | 2011 | 21862480 |
| effects of prior vegetative growth, inoculum density, light, and mating on conidiation of erysiphe necator. | initiation of asexual sporulation in powdery mildews is preceded by a period of superficial vegetative growth of mildew colonies. we found evidence of a quorum-sensing signal in erysiphe necator that was promulgated at the colony center and stimulated conidiation throughout the colony. removal of the colony center after putative signal promulgation had no impact upon timing of sporulation by 48-h-old hyphae at the colony margin. however, removal of the colony center before signaling nearly doubl ... | 2012 | 21848394 |