| [the antibiotic effect of bacteria and fungi on the growth of venturia inaequalis (cke.) wint. in vitro]. | | 1969 | 5199503 |
| structures and pesticidal activities of derivatives of dinitrophenols. xii. in vitro activity of c3 to c13 alpha-branched alkyldinitrophenols and their esters and ethers against the spores of venturia inaequalis and other fungi. | | 1968 | 5726563 |
| the role of extracellular melanoproteins in venturia inaequalis in host susceptibility. | | 1967 | 6038895 |
| characterization of the mitochondrial cytochrome b gene from venturia inaequalis. | a new class of agricultural fungicides derived from the group of antifungal strobilurins acts as specific respiration inhibitors by binding to mitochondrial cytochrome b. the cytochrome b gene was cloned and sequenced from the mitochondrial genome of venturia inaequalis, the causal agent of apple scab. the gene was 10.65 kbp in size and contained seven exons and six introns. the exons encoded a protein of 393 amino acids. comparison of the deduced amino-acid sequence with cytochrome b proteins f ... | 1997 | 9371888 |
| further nutritional studies of venturia inaequalis. | | 1955 | 13278489 |
| relationships between cultural characters and pathogenicity in venturia inaequalis and venturia pirina. | | 1957 | 13416513 |
| the significance of poly-phenolic metabolites of apple and pear in the host relations of venturia inaequalis and venturia pirina. | | 1957 | 13481331 |
| cloning and expression analysis of the atp-binding cassette transporter gene mfabc1 and the alternative oxidase gene mfaox1 from monilinia fructicola. | brown rot, caused by moniliniafructicola (g wint) honey, is a serious disease of peach in all commercial peach production areas in the usa, including south carolina where it has been primarily controlled by pre-harvest application of 14-alpha demethylation (dmi) fungicides for more than 15 years. recently, the qo fungicide azoxystrobin was registered for brown rot control and is currently being investigated for its potential as a dmi fungicide rotation partner because of its different mode of ac ... | 2003 | 14561072 |
| agrobacterium and peg-mediated transformation of the phytopathogen venturia inaequalis. | we report the development of two new transformation systems, polyethylene glycol (peg)-mediated transformation of protoplasts and agrobacterium tumefaciens-mediated transformation of mycelium, for the filamentous ascomycete venturia inaequalis. new binary vectors have been created for the latter. although transformation was initially achieved using a peg-mediated method, this was superseded by the a. tumefaciens-mediated approach. the advantages of the latter include: ease of the protocol, no re ... | 2003 | 12967207 |
| response of scab-susceptible (mcintosh) and scab-resistant (liberty) apple tissues to treatment with yeast extract and venturia inaequalis. | yeast extract and venturia inaequalis treated intact scab-susceptible (mcintosh) and scab-resistant (liberty) apple plants and their organs were analyzed for phenolic metabolites. the major phenolic compounds found in both non-treated and treated leaves were phloridzin and phloretin which accumulated in mm concentrations. untreated and treated stems and roots contained only phloridzin as the major detectable metabolite during the course of the investigation. the accumulation of phloridzin and ph ... | 2003 | 12943766 |
| synthetic method and biological activities of cis-fused alpha-methylene gamma-lactones. | a reliable method was developed for the synthesis of cis-fused alpha-methylene gamma-lactones via alpha-methyl gamma-lactones. bromination of alpha-methyl gamma-lactones with lda/cbr(4) or tmsotf/ptab and successive dehydrobromination with dbu or tbaf of the resulting alpha-bromo-alpha-methyl gamma-lactones gave the desired alpha-methylene gamma-lactones in high yield. this method was successfully applied to the synthesis of biologically active compounds. alpha-methylene gamma-lactone derivative ... | 2003 | 12828467 |
| a method for the isolation of fungistatic microorganisms active against a slowly growing mold: venturia inaequalis (cke) wint. | | 1950 | 15419632 |
| a critical evaluation of the role of alternative oxidase in the performance of strobilurin and related fungicides acting at the qo site of complex iii. | mitochondrial respiration conserves energy by linking nadh oxidation and electron-coupled proton translocation with atp synthesis, through a core pathway involving three large protein complexes. strobilurin fungicides block electron flow through one of these complexes (iii), and disrupt energy supply. despite an essential need for atp throughout fungal disease development, strobilurins are largely preventative; indeed some diseases are not controlled at all, and several pathogens have quickly de ... | 2003 | 12741518 |
| genetic dissection of partial resistance to race 6 of venturia inaequalis in apple. | scab, caused by the fungus venturia inaequalis, is one of the most important diseases of apple (malus x domestica). the major resistance gene, vf, has been widely used in apple breeding programs, but two new races of the fungus (races 6 and 7) are able to overcome this gene. a mapped f1 progeny derived from a cross between the cultivars prima and fiesta has bee n inoculated with two monoconidial strains of race 6. these strains originated from sporulating leaves of 'prima' and a descendant of 'p ... | 2003 | 12723038 |
| a cluster of four receptor-like genes resides in the vf locus that confers resistance to apple scab disease. | the vf locus, derived from the crabapple species malus floribunda 821, confers resistance to five races of the fungal pathogen venturia inaequalis, the causal agent of apple scab disease. in our previous research, the vf locus was restricted to a bac contig of approximately 290 kb covered by five overlapping bac clones. here, we report on cloning of the resistance gene(s) present in the vf bac contig using a highly reliable and straightforward approach. this approach relies on hybridization of l ... | 2002 | 12524365 |
| mechanisms influencing the evolution of resistance to qo inhibitor fungicides. | fungicides inhibiting the mitochondrial respiration of plant pathogens by binding to the cytochrome bc1 enzyme complex (complex iii) at the qo site (qo inhibitors, qois) were first introduced to the market in 1996. after a short time period, isolates resistant to qois were detected in field populations of a range of important plant pathogens including blumeria graminis speer f sp tritici, sphaerotheca fuliginea (schlecht ex fr) poll, plasmopara viticola (berk & ma curtis ex de bary) berl & de to ... | 2002 | 12233175 |
| the role of melanin in the antagonistic interaction between the apple scab pathogen venturia inaequalis and microsphaeropsis ochracea. | the objective of this study was to examine the role of melanin in the interaction between the mycoparasite microsphaeropsis ochracea and the apple scab pathogen venturia inaequalis. melanin was extracted from the cell wall of the pathogen and its chemical and physical properties determined on the basis of biochemical tests and visible and infrared spectra. the physical and chemical characteristics of v inaequalis melanin were similar to the those of synthetic dihydroxyphenylalanine (dopa) melani ... | 2002 | 12030708 |
| sensitivity of venturia inaequalis to trifloxystrobin. | the sensitivity of venturia inaequalis to trifloxystrobin was monitored by both in vitro (spore germination) and in vivo tests (on apple seedlings). there was good correlation between the in vitro and in vivo results. baseline sensitivity was established with 95 bulk isolates from europe between 1995 and 1998 which showed a narrow sensitivity range-factor of up to 17 between the least and most sensitive isolates. monitoring of populations originating from trifloxystrobin-treated and untreated or ... | 2002 | 11975172 |
| synergistic activity of endochitinase and exochitinase from trichoderma atroviride (t. harzianum) against the pathogenic fungus (venturia inaequalis) in transgenic apple plants. | genes from the biocontrol fungus trichoderma atroviride encoding the antifungal proteins endochitinase or exochitinase (n-acetyl-beta-d-hexosaminidase) were inserted into 'marshall mcintosh' apple singly and in combination. the genes were driven by a modified camv35s promoter. the resulting plants were screened for resistance to venturia inaequalis, the causal agent of apple scab, and for effects of enzyme expression on growth. disease resistance was correlated with the level of expression of ei ... | 2001 | 11817541 |
| sensitivity of mitochondrial respiration to different inhibitors in venturia inaequalis. | the sensitivity of venturia inaequalis field isolates to inhibitors of the cytochrome bc1 complex at the qo site (qois) was characterised at the molecular, biochemical and physiological level, and compared to other respiration inhibitors. comparison of a sensitive and a qoi-resistant isolate revealed very high resistance factors both in mycelium growth and spore germination assays. cross-resistance was observed among qois such as trifloxystrobin, azoxystrobin, famoxadone, strobilurin b and myxot ... | 2001 | 11561403 |
| apple contains receptor-like genes homologous to the cladosporium fulvum resistance gene family of tomato with a cluster of genes cosegregating with vf apple scab resistance. | scab caused by the fungal pathogen venturia inaequalis is the most common disease of cultivated apple (malus x domestica borkh.). monogenic resistance against scab is found in some small-fruited wild malus species and has been used in apple breeding for scab resistance. vf resistance of malus floribunda 821 is the most widely used scab resistance source. because breeding a high-quality cultivar in perennial fruit trees takes dozens of years, cloning disease resistance genes and using them in the ... | 2001 | 11310738 |
| characterization of laboratory mutants of venturia inaequalis resistant to the strobilurin-related fungicide kresoxim-methyl. | several agricultural fungicides related to the antifungal strobilurins act as inhibitors of respiration by binding to mitochondrial cytochrome b. two types of laboratory mutants resisting higher doses of the strobilurin-related inhibitor kresoxim-methyl were characterized for venturia inaequalis, the causal agent of apple scab. selection of mutagenized conidia by kresoxim-methyl yielded mutants altered in the expression of alternative respiration during the stage of conidia germination. cytochro ... | 2000 | 11057448 |
| localization of fungal fimbriae by immunocytochemistry in pathogenic and nonpathogenic isolates of venturia inaequalis. | pathogenic and nonpathogenic isolates of venturia inaequalis were grown in liquid culture. hyphae were treated with two types of fimbrial antiserum (au- and av-1) and examined by immunofluorescent microscopy, in order to establish the distribution of fimbrial epitopes in whole cell mounts. the av-1 antiserum was specific for the glycoprotein subunits while the au-antiserum was specific for the protein moieties present on the fimbriae of mycobotryum violaceum. the use of fimbrial antiserum with i ... | 2000 | 11006840 |
| a leucine-rich repeat receptor-like protein kinase (lrpkm1) gene is induced in malus x domestica by venturia inaequalis infection and salicylic acid treatment. | a cdna clone encoding a leucine-rich repeat (lrr) receptor-like protein kinase (lrpkm1) of malus x domestica cv. florina has been isolated using as a heterologous probe a cloned gene encoding a polygalacturonase-inhibiting protein (pgip) of phaseolus vulgaris l. a genomic clone containing the 5'-regulatory region and a 5' portion of the open reading frame of the lrpkm1 gene has also been isolated. an open reading frame of 2997 nt (999 amino acids) was present in the cdna clone, encoding a recept ... | 1999 | 10527419 |
| [ultrastructural study of host-parasite relations: early phases of venturia inaequalis installation on susceptible and resistance apple leaves]. | the penetration mechanism study of venturia inaequalis is undertaken on leaves of scab-susceptible and scab-resistant apple cultivars. the penetration through the cuticle occurs whatever the host phenotype. the resistance will be expressed when the infectious hyphae is in contact with the epidermal cell wall. the epidermal cell of susceptible variety does not show any modification. the resistant variety reaction is very fast, since twenty hours after penetration many wall appositions are setting ... | 1994 | 8054694 |
| dna markers linked to malus floribunda 821 scab resistance. | breeding resistant apple plants is an alternative way to control fungal pathogens reducing the environmental impact due to the use of pesticides. the breeding of apple cultivars resistant to venturia inaequalis could be much improved by marker-assisted selection. a molecular marker closely linked to the resistance locus called vf could replace selection based on infection studies. to find such molecular markers, dna of progenies from crossings of a resistant and a susceptible apple tree was subj ... | 1994 | 7948915 |
| respiratory enzymes in venturia inaequalis. | | 1970 | 5437389 |
| the relationship of genes for pathogenicity and certain other characters in venturia inaequalis (cke.) wint. | | 1957 | 17247728 |
| the ultrastructure of the spilocaea state of venturia inaequalis in vivo. | there are indications that the fungus enzymatically degrades the cuticle and epidermal cell wall. the epidermal cells and to a lesser degree the palisade mesophyll cells beneath a sporulating lesion (susceptible reaction) are killed or seriously disrupted. various stages of conidiogenesis, including development of the pprimary conidium, were observed. a conidium is delimited by a two-layered transverse septum. before condium secession, a new two-layered inner wall is laid down around the entire ... | 1976 | 986869 |
| somatic variation plays a key role in the evolution of the vf gene family residing in the vf locus that confers resistance to apple scab disease. | a cluster of four receptor-like genes has been previously identified in the vf locus of the crabapple malus floribunda clone 821 that confers resistance to five races of the fungal pathogen venturia inaequalis, the casual agent of apple scab disease. pairwise comparisons of the four vf paralogs in both promoter and coding regions reveal their timeline evolutionary history. the four vf paralogs have evolved from four ancient vf members resulting from two sequential duplication events of a single ... | 2004 | 15186797 |
| modeling the qo site of crop pathogens in saccharomyces cerevisiae cytochrome b. | saccharomyces cerevisiae has been used as a model system to characterize the effect of cytochrome b mutations found in fungal and oomycete plant pathogens resistant to q(o) inhibitors (qois), including the strobilurins, now widely employed in agriculture to control such diseases. specific residues in the q(o) site of yeast cytochrome b were modified to obtain four new forms mimicking the q(o) binding site of erysiphe graminis, venturia inaequalis, sphaerotheca fuliginea and phytophthora megasper ... | 2004 | 15153117 |
| the nutritional requirements of venturia inaequalis. | | 1955 | 14392293 |
| some effects of respiration inhibitors and 0-coumaric acid on the inhibition of sporulation in venturia inaequalis. | | 1963 | 14045513 |
| studies of the significance of polyphenolic host metabolites in the nutrition of venturia inaequalis and venturia pirina. | | 1957 | 13475681 |
| simultaneous silencing of multiple genes in the apple scab fungus, venturia inaequalis, by expression of rna with chimeric inverted repeats. | rna-mediated gene silencing has been demonstrated in plants, animals, and more recently in filamentous fungi. here, we report high frequency, rna-mediated gene silencing in the apple scab fungus, venturia inaequalis. the green fluorescent protein (gfp) transgene was silenced in a gfp-expressing transformant. an endogenous gene, trihydroxynaphthalene reductase (thn), involved in melanin biosynthesis, was also silenced. silencing of these two genes resulted in obvious phenotypes in vitro. high fre ... | 2004 | 15341918 |
| molecular markers linked to the apple scab resistance gene vbj derived from malus baccata jackii. | breeding for scab-resistant apple cultivars by pyramiding several resistance genes in the same genetic background is a promising way to control apple scab caused by the fungus venturia inaequalis. to achieve this goal, dna markers linked to the genes of interest are required in order to select seedlings with the desired resistance allele combinations. for several apple scab resistance genes, molecular markers are already available; but until now, none existed for the apple scab resistance gene v ... | 2004 | 15365630 |
| investigations on epiphytic living pseudomonas species from malus domestica with an antagonistic effect to venturia inaequalis on isolated plant cuticle membranes. | in order to understand better the survival and mutual interaction of epiphytic bacteria and fungi on apple plants, bacteria collected from these plants were cultivated on intact adaxial, stoma free cuticle membranes originally obtained from apple. the bacteria were labelled with luciferase genes from vibrio harveyi in order to follow up their development and activity on the isolated cuticles. our finding was that the epiphytic bacteria can have access to nutrients below the cuticle without causi ... | 2004 | 15479248 |
| characterisation of mal d 1-related genes in malus. | it has been suggested that there are at least 15 mal d 1-related (pr10) genes in one genotype of apple (malus x domestica borkh). we sequenced cdna libraries of cultivar 'royal gala' and identified 12 members of the mal d 1 family, including the previously reported mal d 1b and mal d 1d, an allelic variant of the previously reported mal d 1a. eight mal d 1 gene products were expressed in tree-ripened fruit, in either the cortex or the skin, and most of these were also expressed in leaves in resp ... | 2004 | 15604687 |
| inhibiting effects of resveratrol and its glucoside piceid against venturia inaequalis, the causal agent of apple scab. | resveratrol is a phytoalexin produced in different unrelated plant species such as grapevine and peanut. the effect of resveratrol and its glucoside trans-resveratrol-3-o-beta-d-glycopyranosid (piceid) against venturia inaequalis, the causal agent of apple scab, was evaluated using a newly established test based on enzymatically isolated cuticular membranes (cms) from apple (malus domestica borkh.) leaves. the test substances resveratrol and piceid were either sorbed to cms before inoculation wi ... | 2005 | 15656672 |
| up-regulation of pathogenesis-related proteins in the apoplast of malus domestica after application of a non-pathogenic bacterium. | the intercellular washing fluid (iwf) of malus domestica cv. holsteiner cox before and after application of the non-pathogenic bacterium pseudomonas fluorescens bk3 to the leaves was investigated in a comparative manner. sds-page in combination with esi q-tof mass spectrometry, and homology search in relevant data bases revealed the highly up-regulated expression of several pathogenesis-related plant proteins in the apoplast of the leaves treated with p. fluorescens. these proteins were beta3-1, ... | 2004 | 15666544 |
| identification of functional apple scab resistance gene promoters. | apple scab (venturia inaequalis) is one of the most damaging diseases affecting commercial apple production. some wild malus species possess resistance against apple scab. one gene, hcrvf2, from a cluster of three genes derived from the wild apple malus floribunda clone 821, has recently been shown to confer resistance to apple scab when transferred into a scab-susceptible apple variety. for this proof-of-function experiment, the use of the 35s promoter from cauliflower mosaic virus was reliable ... | 2005 | 15726316 |
| purification and partial characterization of an extracellular melanoprotein from the fungus venturia inaequalis. | the fungus venturia inaequalis clone no. 36 isolated from malus domestica cv. gloster excretes a melanoprotein of 36 kda in relatively high amounts during growth in liquid culture. the protein was isolated from the culture medium and purified to homogeneity. it was shown to contain melanin. after raising an antiserum against the isolated protein, the protein could be shown to be located in the apoplast fluid of the v. inaequalis infected malus domestica cv. elstar. partial sequencing of the prot ... | 2005 | 15787254 |
| characterization by suppression subtractive hybridization of transcripts that are differentially expressed in leaves of apple scab-resistant and susceptible cultivars of malus domestica. | in order to compare transcription profiles in cultivars of malus domestica that are differentially sensitive to apple scab (venturia inaequalis), two cdna libraries were constructed using the suppression subtractive hybridization (ssh) method. subtraction hybridization was performed between cdnas from uninfected young leaves of the resistant cultivar remo and the susceptible elstar. in total, 480 est clones were obtained: 218 (elstar) clones represent transcripts that are preferentially expresse ... | 2005 | 15812649 |
| the vh8 locus of a new gene-for-gene interaction between venturia inaequalis and the wild apple malus sieversii is closely linked to the vh2 locus in malus pumila r12740-7a. | the wild apple (malus sieversii) is a large-fruited species from central asia, which is used as a source of scab resistance in cultivar breeding. phytopathological tests with races of venturia inaequalis were performed to differentiate scab-resistance genes in malus as well as an avirulence gene in the pathogen. a novel gene-for-gene interaction between v. inaequalis and malus was identified. the locus of the scab-resistance gene vh8 is linked with, or possibly allelic to, that of the vh2 gene i ... | 2005 | 15869661 |
| venturia inaequalis (cke.) wint.; further studies on the inheritance of pathogenicity. | | 1948 | 18884233 |
| venturia inaequalis (cke.) wint.; the influence of carbon and nitrogen sources and vitamins on growth in vitro. | | 1948 | 18884234 |
| an in vitro study on the postinfection activities of copper hydroxide and copper sulfate against conidia of venturia inaequalis. | the postinfection activities of copper hydroxide [cu(oh)2] and copper sulfate (cuso4) against apple scab (venturia inaequalis) were evaluated in an in vitro study. our intention was to support the aim of reducing copper application rates by appropriate timing of applications. experiments were conducted at 20 degrees c with leaf disks and isolated cuticular membranes (cm) of malus x domestica 'gloster' and 'elstar'. conidia of v. inaequalis were used as the inoculum. in untreated controls, 7.9 an ... | 2006 | 16448200 |
| activation of the pathogen-inducible gst1 promoter of potato after elicitation by venturia inaequalis and erwinia amylovora in transgenic apple (malus x domestica). | rather than using a constitutive promoter to drive transgenes for resistance against fungal and bacterial diseases in genetic engineering of apple (malus x domestica) cultivars, a promoter induced only after infection was preferred. the ability of the pgst1 promoter from potato (solanum tuberosum l.) to drive expression of the gusa reporter gene was determined in two genotypes of apple: the fruit cultivar royal gala and the m.26 rootstock. beta-glucuronidase activity in the transgenic lines grow ... | 2006 | 16475012 |
| construction of a contig of bac clones spanning the region of the apple scab avirulence gene avrvg. | the ascomycete venturia inaequalis, causal pathogen of apple scab, underlies a gene-for-gene relationship with its host plant apple (malus spp.). 'golden delicious', one of the most common cultivated apples in the world, carries the ephemeral resistance gene vg. avirulence gene avrvg, matching resistance gene vg has recently been mapped on the v. inaequalis genome. in this paper, we present the construction of a bac library from a v. inaequalis avrvg isolate. the library is composed of 7680 clon ... | 2007 | 16904351 |
| development and linkage mapping of e-sts and rga markers for functional gene homologues in apple. | linkage maps developed from known-function genes can be valuable in the candidate gene mapping approach. a set of 121 expressed sequence tagged site (e-sts) primer pairs were tested on a framework genetic linkage map of apple (malus x domestica borkh.) constructed using simple sequence repeats (ssrs) and randomly amplified polymorphic dna (rapd) markers. these known-function gene markers, e-stss, were supplemented by markers for resistance gene analogues (rgas), designed based on conserved motif ... | 2006 | 17036071 |
| venturia inaequalis-inhibiting diels-alder adducts from morus root bark. | in organic apple orcharding there is a continuous need for natural fungicides effective against venturia inaequalis (cooke) winter, the causal agent of apple scab. in this study an in vitro assay is presented for determining the germination inhibitory potential of extracts and pure compounds. from a screening of plant extracts, the methanol extract of morus root bark revealed distinct v. inaequalis inhibiting qualities, which were subjected to a bioguided fractionation. among the isolated metabo ... | 2006 | 17061817 |
| origin and colonization history of newly virulent strains of the phytopathogenic fungus venturia inaequalis. | plant resistance based on a gene-for-gene relationship tends not to be durable because virulent strains can emerge through mutation and colonize formerly resistant cultivars over large areas. our objective was to determine the origin and colonization history of newly virulent strains of the fungus venturia inaequalis. four hundred and eighty-one strains from seven multi-cultivar orchards within a 300km wide area were collected from a cultivar carrying the overcome vf-gene (vfcv populations) and ... | 2007 | 17166752 |
| mapping of the apple scab-resistance gene vb. | apple scab, caused by the fungus venturia inaequalis, is the major production constraint in temperate zones with humid springs. normally, its control relies on frequent and regular fungicide applications. because this control strategy has come under increasing criticism, major efforts are being directed toward the breeding of scab-resistant apple cultivars. modern apple breeding programs include the use of molecular markers, making it possible to combine several different scab-resistance genes i ... | 2006 | 17213905 |
| recombinant dna technology in apple. | this review summarizes the achievements of almost 20 years of recombinant dna technology applied to apple, grouping the research results into the sections: developing the technology, insect resistance, fungal disease resistance, self-incompatibility, herbicide resistance, fire blight resistance, fruit ripening, allergens, rooting ability, and acceptance and risk assessment. the diseases fire blight, caused by erwinia amylovora, and scab, caused by venturia inaequalis, were and still are the prim ... | 2007 | 17522823 |
| the systematic position of phaeocryptopus gaeumannii. | phaeocryptopus gaeumannii, causal agent of the douglas-fir foliar disease swiss needle cast, is the only known pathogenic species of the genus. current classifications place phaeocryptopus in the venturiaceae (pleosporales), typified by the apple-scab pathogen venturia inaequalis. all core members of this family have hyphomycetous anamorphs. we sought to confirm these relationships by means of phylogenetic analyses of the small (ssu) and large (lsu) subunits and internal transcribed spacer (its) ... | 2007 | 17682777 |
| mapping quantitative field resistance against apple scab in a 'fiesta' x 'discovery' progeny. | abstract breeding of resistant apple cultivars (malus x domestica) as a disease management strategy relies on the knowledge and understanding of the underlying genetics. the availability of molecular markers and genetic linkage maps enables the detection and the analysis of major resistance genes as well as of quantitative trait loci (qtl) contributing to the resistance of a genotype. such a genetic linkage map was constructed, based on a segregating population of the cross between apple cvs. fi ... | 2003 | 18944365 |
| heterothallism in venturia inaequalis. | | 1937 | 17730686 |
| toxicity of the sodium salt of dinitro-o-cresol to venturia inaequalis. | | 1939 | 17829074 |
| overexpression of the apple mpnpr1 gene confers increased disease resistance in malus x domestica. | the npr1 gene plays a pivotal role in systemic acquired resistance in plants. its overexpression in arabidopsis and rice results in increased disease resistance and elevated expression of pathogenesis-related (pr) genes. an npr1 homolog, mpnpr1-1, was cloned from apple (malus x domestica) and overexpressed in two important apple cultivars, galaxy and m26. apple leaf pieces were transformed with the mpnpr1 cdna under the control of the inducible pin2 or constitutive cauliflower mosaic virus (camv ... | 2007 | 17990964 |
| influence of supplementary lighting during artificial scab inoculation tests in an apple breeding programm focused on partial resistance. | in 1988, the department of biological control and plant genetic resources at the walloon agricultural research centre started an apple-breeding programme using local genetic resources and modern varieties. our objective is to create high quality commercial cultivars with durable resistance to scab (venturia inaequalis), powdery mildew (podosphaera leucotricha) and canker (nectria galligena). the breeding strategy is based on crossing old apple cultivars and landraces selected as parents for low ... | 2006 | 17390863 |
| two receptor-like genes, vfa1 and vfa2, confer resistance to the fungal pathogen venturia inaequalis inciting apple scab disease. | the vf locus, originating from the crabapple species malus floribunda 821, confers resistance to five races of the fungal pathogen venturia inaequalis, the causal agent of apple scab disease. previously, a cluster of four receptor-like genes, vfa1, vfa2, vfa3, and vfa4, was identified within the vf locus. because the amino-acid sequence of vfa3 is truncated, it was deemed nonfunctional. in this study, each of the three full-length vfa genes was introduced into a plant cloning vector, pcambia2301 ... | 2008 | 18321190 |
| study on the sensitivity of venturia inaequalis to anilinopyrimidine fungicides in italy. | | 2007 | 18396841 |
| management of apple scab (venturia inaequalis) in romania based on electronic warnings. | apple scab, venturia inaequalis (cke) wint., is a major problem in romanian apple orchards and is responsible for serious economic losses. the purchase of spraying equipment and phytopharmaceutical products is very expensive in comparison to the income of local apple growers. this is one of the reasons why reduced fungicide sprayings are becoming more and more important. that's why a project was started to investigate the influence of west-european control measures and to improve interaction bet ... | 2007 | 18396842 |
| a genome-wide functional investigation into the roles of receptor-like proteins in arabidopsis. | receptor-like proteins (rlps) are cell surface receptors that typically consist of an extracellular leucine-rich repeat domain, a transmembrane domain, and a short cytoplasmatic tail. in several plant species, rlps have been found to play a role in disease resistance, such as the tomato (solanum lycopersicum) cf and ve proteins and the apple (malus domestica) hcrvf2 protein that mediate resistance against the fungal pathogens cladosporium fulvum, verticillium spp., and venturia inaequalis, respe ... | 2008 | 18434605 |
| inheritance studies of apple scab resistance and identification of rvi14, a new major gene that acts together with other broad-spectrum qtl. | scab, caused by the fungal pathogen venturia inaequalis, is the most common disease of cultivated apple (malus xdomestica). the fungal races 6 and 7 have now overcome the major resistance gene vf, which is widely used in apple breeding programmes. new breeding strategies to achieve durable resistance are thus necessary. the aim of this study was to determine the genetic basis of quantitative resistance of the apple cultivar 'dülmener rosenapfel', known to be scab resistant under different enviro ... | 2008 | 18650955 |
| a computer-controlled environmental chamber for the study of aerial fungal spore release. | abstract an environmental chamber was designed to study aerial release of spores of ascomycetes and hyphomycetes, based on a device developed by c. m. leach. relative humidity (rh), temperature, red (660 nm) and infrared (880 nm) light, leaf wetness, wind speed, vibration, and rain events are controlled and monitored within the chamber via an rtc-hc11 real-time controller and data-acquisition system. a basic11 computer program is uploaded to and controls the system. the program requests values f ... | 1997 | 18945044 |
| two novel venturia inaequalis genes induced upon morphogenetic differentiation during infection and in vitro growth on cellophane. | venturia inaequalis is a hemibiotrophic ascomycete that causes apple scab. germ tubes, from conidia or ascospores, penetrate the leaf or fruit surface directly via appressoria-like swellings; subsequently the hyphae divide laterally to form a stroma between the cuticle and the outer wall of the epidermal cells. this morphological switch can be mimicked by growing the fungus in vitro on cellophane discs. the aim of this work was to identify genes upregulated in planta using growth on cellophane a ... | 2008 | 18692586 |
| monitoring of venturia inaequalis harbouring the qoi resistance g143a mutation in french orchards as revealed by pcr assays. | genetic resistance to qoi fungicides may account for recent failures to control venturia inaequalis (cooke) winter in french orchards. two pcr-based assays were developed to detect the g143a point mutation in the fungal mitochondrial cytochrome b gene. the mutation is known to confer a high level of resistance to qoi fungicides. occurrence of the g143a mutation in french field isolates collected from 2004 to 2007 was monitored. | 2009 | 18823065 |
| cytochrome b gene structure and consequences for resistance to qo inhibitor fungicides in plant pathogens. | the cytochrome b (cyt b) gene structure was characterized for different agronomically important plant pathogens, such as puccinia recondita f sp tritici (erikss) co johnston, p graminis f sp tritici erikss and hennings, p striiformis f sp tritici erikss, p coronata f sp avenae p syd & syd, p hordei gh otth, p recondita f sp secalis roberge, p sorghi schwein, p horiana henn, uromyces appendiculatus (pers) unger, phakopsora pachyrhizi syd & p syd, hemileia vastatrix berk & broome, alternaria solan ... | 2006 | 16688790 |
| baseline toxicity of several pesticides to hyaliodes vitripennis (say) (hemiptera: miridae). | hyaliodes vitripennis (say) is a univoltine indigenous predacious mirid. it has been reported in several orchards where ipm programmes are used. it is a generalist, and feeds on phytophagous mites in addition to other arthropods. in quebec, a foliar application of imidacloprid, deltamethrin or lambda-cyhalothrin is used at least once per season to manage arthropod pests such as leafhoppers and leaf-eating caterpillars. meanwhile, several applications of metiram, flusilazole, myclobutanil and man ... | 2001 | 11721516 |
| chitinases of trichoderma atroviride induce scab resistance and some metabolic changes in two cultivars of apple. | abstract this study reports the combination of a transgene-mediated defense mechanism with a conventionally bred resistance in order to improve apple scab resistance. two cultivars of apple (galaxy, scab-susceptible, and ariane, carrying the vf resistance gene) were transformed with endochitinase and exochitinase genes derived from the biocontrol fungus trichoderma atroviride. the obtained transgenic lines were analyzed for the expression of both genes and resistance to two races of the pathogen ... | 2003 | 18943613 |
| localized melanization of appressoria is required for pathogenicity of venturia inaequalis. | abstract during formation of appressoria produced from conidia and ascospores of venturia inaequalis, a dark brown ring structure was detected at the base of appressoria. this melanized appressorial ring structure (mars) was attached to the leaf surface like a sealing ring and formed the fungus-plant interface; it is believed to be required for pathogen penetration of the cuticle. neither germ tubes nor infection structures beneath the cuticle were found to be visibly melanized. mars were formed ... | 2007 | 18943680 |
| a genetic linkage map of venturia inaequalis, the causal agent of apple scab. | venturia inaequalis is an economically-important disease of apple causing annual epidemics of scab worldwide. the pathogen is a heterothallic ascomycete with an annual cycle of sexual reproduction on infected apple leaf litter, followed by several cycles of asexual reproduction during the apple growing season. current disease control is achieved mainly through scheduled applications of fungicides. genetic linkage maps are essential for studying genome structure and organisation, and are a valuab ... | 2009 | 19689797 |
| effect of timing of application of the biological control agent microsphaeropsis ochracea on the production and ejection pattern of ascospores by venturia inaequalis. | abstract field and in vitro trials were conducted to establish the influence of the biological control agent microsphaeropsis ochracea on the ejection pattern of ascospores by venturia inaequalis and on apple scab development, and to establish the best timing of application. the ejection pattern of ascospores was similar on leaves sprayed with m. ochracea and on untreated leaves. fall application of m. ochracea combined with a delayed-fungicide program was evaluated in orchards with intermediate ... | 2004 | 18943700 |
| on the origin and spread of the scab disease of apple: out of central asia. | venturia inaequalis is an ascomycete fungus responsible for apple scab, a disease that has invaded almost all apple growing regions worldwide, with the corresponding adverse effects on apple production. monitoring and predicting the effectiveness of intervention strategies require knowledge of the origin, introduction pathways, and population biology of pathogen populations. analysis of the variation of genetic markers using the inferential framework of population genetics offers the potential t ... | 2008 | 18197265 |
| brown spot control on pear: infection models versus the inoculum pressure in belgium. | stemphylium conidia and pleospora ascospores were monitored in pear orchards in the region of haspengouw in belgium during the infectious periods of brown spot disease (end may - end august) in the years 2002, 2004 and 2005. the seasonal and daily dynamics of the captured fungal spores are discussed and a correlation analysis was performed to determine possible correlation with weather parameters. furthermore the fungicide cover obtained by spraying upon climatological infection risk is compared ... | 2006 | 17390829 |
| alternatives to copper in scab control affect mineral composition in leaves and fruits of apple varieties with reduced scab susceptibility or scab resistance. | scab (venturia inaequalis) is the principal disease endangering both integrated and organic apple production. scab pressure tends to build up over the years and organic farmers rely mainly on copper and sulphur treatments for control. the use of cu in crop protection received scrutiny in recent years as this metal tends to accumulate in soil and substrates. a number of alternative organic control substances have been proposed, with variable success in scab control. we investigated the effect of ... | 2006 | 17390850 |
| quantitative trait loci (qtl) analysis reveals both broad-spectrum and isolate-specific qtl for scab resistance in an apple progeny challenged with eight isolates of venturia inaequalis. | abstract the major scab resistance gene vf, extensively used in apple breeding programs, was recently overcome by the new races 6 and 7 of the fungal pathogen venturia inaequalis. new, more durable, scab resistance genes are needed in apple breeding programs. f(1) progeny derived from the cross between partially resistant apple cv. discovery and apple hybrid 'tn10-8' were inoculated in the greenhouse with eight isolates of v. inaequalis, including isolates able to overcome vf. one major resistan ... | 2004 | 18944113 |
| the 14alpha-demethylasse(cyp51a1) gene is overexpressed in venturia inaequalis strains resistant to myclobutanil. | abstract we identified the cytochrome p450 sterol 14alpha-demethylase (cyp51a1) gene from venturia inaequalis and optional insertions located upstream from cyp51a1 and evaluated their potential role in conferring resistance to the sterol demethylation-inhibitor (dmi) fungicide my-clobutanil. the cyp51a1 gene was completely sequenced from one my-clobutanil sensitive (s) and two myclobutanil-resistant (r) strains. no nucleotide variation was found when the three sequences were aligned. allele-spec ... | 2001 | 18944284 |
| effect of fall application of fungal antagonists on spring ascospore production of the apple scab pathogen, venturia inaequalis. | abstract the influences of microsphaeropsis sp., m. arundinis, ophiostoma sp., diplodia sp., and trichoderma sp., all antagonists of venturia inaequalis, on ascospore production were evaluated under natural conditions and compared with urea and athelia bombacina, a known antagonist. in the autumn, the fungi were applied to leaf disks artificially inoculated with v. inaequalis and to scabbed apple (malus domestica) leaves incubated under controlled and natural conditions. in addition, large-scale ... | 2000 | 18944569 |
| expression of endochitinase from trichoderma harzianum in transgenic apple increases resistance to apple scab and reduces vigor. | abstract the goal of this research was to improve scab resistance of apple by transformation with genes encoding chitinolytic enzymes from the bio-control organism trichoderma harzianum. the endochitinase gene, as cdna and genomic clones, was transferred into apple cv. marshall mcintosh by agrobacterium-transformation. a total of 15 lines were identified as transgenic by nptii enzyme-linked immunosorbent assay and polymerase chain reaction and confirmed by southern analysis. substantial differen ... | 2000 | 18944574 |
| genetics of host-pathogen relationships between venturia inaequalis races 6 and 7 and malus species. | abstract resistance to scab originating from malus floribunda clone 821 is the most widely form of resistance used in apple breeding programs. a dominant gene, named vf, was introgressed from this clone into recent cultivars, although the genetic determinants of the resistance of m. floribunda 821 are apparently more complex than a single gene. the appearance of new races overcoming the resistance of cultivars with the vf gene, the parental clone, or both made it possible to undertake a genetic ... | 2000 | 18944614 |
| identification of microsatellite markers and their application to population genetics of venturia inaequalis. | abstract microsatellite markers of venturia inaequalis were developed using genomic libraries of v. inaequalis enriched for the simple sequence repeats (tc)(n) and (aac)(n). seven markers, three with (tc)(n) repeats and four with (aac)(n) repeats, were selected for the analyses of 350 isolates of v. inaequalis collected from 11 sites in europe. polymorphism in the (tc)(n) repeats was higher than in the (aac)(n) repeats. nei's expected genetic diversity (h(e)) varied between 0.52 and 0.96 for the ... | 1999 | 18944702 |
| characterization of ribosomal dna from venturia inaequalis and its phylogenetic relationship to rdna from other tree-fruit venturia species. | abstract a portion of the 18s ribosomal dna (rdna) gene, the internal transcribed spacers (its1 and its2), and the 5.8s rdna gene were polymerase chain reaction-amplified from strains and field populations of venturia inaequalis and assessed for genetic variation. a previously reported optional group i intron in the 18s rdna gene of v. inaequalis was detected in 75.0% of 92 strains collected worldwide and in 61.1 and 71.2% of 54 and 59 strains from two michigan orchards, respectively. sequence a ... | 1999 | 18944810 |
| influence of light, relative humidity, and maturity of populations on discharge of ascospores of venturia inaequalis. | abstract ascospore release in 20 populations of venturia inaequalis was generally suppressed in wind tunnel tests during darkness and simulated rain, but the following relieved this suppression: (i) exposure to low relative humidity during simulated rain and (ii) protracted incubation of leaf samples and the consequent senescence of the pathogen population. no counterpart to (i) was observed under orchard conditions. although v. inaequalis also released a high percentage of ascospores during dar ... | 1998 | 18944867 |
| 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 likely involves a sequence of events, including (i) attachment and local penetration of microsphaeropsis sp. into v. inaequalis hyphae; (ii) induction of host structural response at ... | 1998 | 18944932 |
| acquisition of resistance to sterol demethylation inhibitors by populations of venturia inaequalis. | abstract acquisition of resistance to sterol demethylation inhibitors (dmis) by populations of venturia inaequalis was investigated using a microscopical method developed by c. siebels and k. mendgen. microscopical analysis of conidiophore formation enabled the earlier detection of resistance and a clearer distinction between dmi-resistant and dmi-sensitive populations than other in vivo methods commonly used to analyze inhibitory effects of fungicides. in addition, because observations were mad ... | 1997 | 18945029 |
| genome-wide snp identification by high-throughput sequencing and selective mapping allows sequence assembly positioning using a framework genetic linkage map. | determining the position and order of contigs and scaffolds from a genome assembly within an organism's genome remains a technical challenge in a majority of sequencing projects. in order to exploit contemporary technologies for dna sequencing, we developed a strategy for whole genome single nucleotide polymorphism sequencing allowing the positioning of sequence contigs onto a linkage map using the bin mapping method. | 2010 | 21192788 |
| ascospore release and infection of apple leaves by conidia and ascospores of venturia inaequalis at low temperatures. | abstract mills' infection period table describes the number of hours of continuous leaf wetness required at temperatures from 6 to 25 degrees c for infection of apple leaves by ascospores of venturia inaequalis and reports that conidia require approximately two-thirds the duration of leaf wetness required by ascospores at any given temperature. mills' table also provides a general guideline that more than 2 days of wetting is required for leaf infection by ascospores below 6 degrees c. although ... | 1997 | 18945039 |
| phytoalexin production in an apple cultivar resistant to venturia inaequalis. | abstract cell suspension cultures of the scab-resistant apple (malus x domestica) cultivar liberty were challenged with yeast extract to mimic the effect of biological stress such as fungal invasion. the cells responded to the challenge by production of novel compounds. suspension cultures of the scab-susceptible cultivar mcintosh, when similarly challenged, showed no detectable response. the major compound produced by scab-resistant cells in response to the challenge has been identified as the ... | 1997 | 18945056 |
| germinability of venturia inaequalis conidia exposed to sunlight. | abstract detached conidia of venturia inaequalis were exposed simultaneously outdoors to direct sunlight or in an adjacent ventilated enclosure in darkness for periods ranging from 0.5 to 16.5 h. in addition, conidia were either exposed or not exposed to uv light (254 nm) from 1 to 64 min in the laboratory. after exposure, conidia were placed on water agar in closed petri dishes and allowed 24 h to germinate. germinability of conidia in the laboratory was reduced up to 95% by doses of uv(254) of ... | 1997 | 18945081 |
| detection and quantification of resistance of venturia inaequalis populations to sterol demethylation inhibitors. | abstract monoconidial isolates of venturia inaequalis were collected in 1990 and 1991 from orchards in new york, michigan, and nova scotia that had never or only sporadically been treated with fungicides acting as sterol demethylation inhibitors (dmis). sensitivities of isolates to two representative dmis (fenarimol and myclobutanil) were determined by a sensitivity test based on the relative growth (rg) of mycelial colonies at one discriminatory dose. mean isolate sensitivities were not signifi ... | 1997 | 18945140 |
| heterologous expression, isotopic-labeling and immuno-characterization of cin1, a novel protein secreted by the phytopathogenic fungus venturia inaequalis. | the phytopathogenic fungus venturia inaequalis causes scab of apple. once this fungus penetrates the plant surface, it forms a specialized body called a stroma between the inner cuticle surface and the epidermal cell wall. a novel v. inaequalis gene, cin1, is strongly up-regulated in the early stages of infection. this gene codes for a 523 residue secreted protein, containing eight imperfect repeats of approximately 60 amino acids. cin1 was expressed in the methanolytic yeast pichia pastoris usi ... | 2009 | 19297691 |
| candidate effector gene identification in the ascomycete fungal phytopathogen venturia inaequalis by expressed sequence tag analysis. | the hemi-biotrophic fungus venturia inaequalis infects members of the maloideae, causing the economically important apple disease, scab. the plant-pathogen interaction of malus and v. inaequalis follows the gene-for-gene model. cdna libraries were constructed, and bioinformatic analysis of the resulting expressed sequence tags (ests) was used to characterize potential effector genes. effectors are small proteins, secreted in planta, that are assumed to facilitate infection. therefore, a cdna lib ... | 2009 | 19400844 |
| within- and between-orchard variability in the sensitivity of venturia inaequalis to myclobutanil, a dmi fungicide, in the uk. | myclobutanil, a demethylation inhibitor (dmi) fungicide, is an important fungicide for controlling apple scab and powdery mildew. overuse of this fungicide has led to establishment of scab isolates with reduced sensitivity to this fungicide in several countries. experiments were conducted to determine the sensitivity of the causal agent of apple scab, venturia inaequalis (cooke) winter, to myclobutanil in the uk, in order to assess whether there is a relationship between fungal insensitivity and ... | 2009 | 19606427 |
| profiling fruit volatiles in the progeny of a 'royal gala' x 'granny smith' apple (malus x domestica) cross. | volatile flavor compounds from the fruit of the progeny of two apple (malus x domestica) cultivars with distinctive flavor and volatile profiles, 'royal gala' and 'granny smith', were measured by headspace gas chromatography-mass spectrometry over two fruiting seasons. principal component analysis separated the volatile profiles into two groups according to the amounts produced of butyl, 2-methybutyl, pentyl, and hexyl acetates and of ethyl butanoate, butanol, 2-methylbutanol, and hexanol. fruit ... | 2009 | 19691320 |
| gene silencing to investigate the roles of receptor-like proteins in arabidopsis. | receptor-like proteins (rlps) are cell surface receptors that play important roles in various processes. in several plant species rlps have been found to play a role in disease resistance, including the tomato cf and ve proteins and the apple hcrvf proteins that mediate resistance against the fungal pathogens cladosporium fulvum, verticillium spp., and venturia inaequalis, respectively. the arabidopsis genome contains 57 atrlp genes. two of these, clv2 (atrlp10) and tmm (atrlp17), have well-char ... | 2008 | 19704533 |
| localized adhesion of nongerminated venturia inaequalis conidia to leaves and artificial surfaces. | adhesion to the host surface is the first step for successful plant pathogen development and has been reported to be associated with both passive and active processes. for conidia of venturia inaequalis, which depend on leaf wetness for germination, this process has not yet been described. conidia of v. inaequalis adhered to wet hydrophobic surfaces immediately after contact to the surface, hours before initiation of germination. attachment of nongerminated conidia was much better on hydrophobic ... | 2008 | 18943251 |
| spatial distribution of venturia inaequalis airborne ascospores in orchards. | abstract apple scab (venturia inaequalis) causes important economic losses in many apple production areas of the world. the disease is controlled by numerous fungicide applications regardless of the presence of ascospores in the orchard. airborne ascospore concentration (aac) can be measured in real time to time fungicide applications. however, the level of heterogeneity of the aac in commercial orchards was unknown. consequently, the spatial distribution of v. inaequalis ascospores was studied ... | 2002 | 18943274 |
| breakdown of the scab resistance gene vf in apple leads to a founder effect in populations of the fungal pathogen venturia inaequalis. | abstract the recent breakdown of vf, a major resistance gene to apple scab, provided an opportunity to analyze a population genetic process within the matching virulent subpopulation of the fungus venturia inaequalis. we utilized the amplified fragment length polymorphism technique and allelic variation at four microsatellite loci to assess genetic structure of 133 isolates of v. inaequalis from a single commercial apple orchard sampled from one cultivar carrying the vf gene (judeline) and three ... | 2004 | 18944112 |