| the genetics of host-pathogen coevolution: implications for genetic resource conservation. | the results of long-term studies of coevolution in the hordeum vulgare-rhynchosporium secalis pathosystem are summarized. the genetic systems of barley (host) and r. secalis (pathogen) are complementary: gene-for-gene interactions among loci affect many traits, leading to self-regulating adjustments over generations between host and pathogen populations. different pathotypes differ widely in their ability to damage the host, and different host-resistance alleles differ widely in their ability to ... | 1990 | 2332610 |
| coevolution of host and pathogen populations in the hordeum vulgare-rhynchosporium secalis pathosystem. | isolates of rhynchosporium secalis collected from two experimental barley populations were scored for putative isozyme, colony color, and virulence loci. allelic frequencies, multilocus haplotype frequencies, and multilocus genetic structure differed in the two populations of r. secalis; haplotypes also differed widely from each other in virulence. the average virulence of isolates collected from the more resistant host population was greater than the average virulence of the isolates collected ... | 1989 | 2726757 |
| genetic variability for pathogenicity, isozyme, ribosomal dna and colony color variants in populations of rhynchosporium secalis. | samples of rhynchosporium secalis were collected from two experimental barley populations known to carry a diverse array of alleles for resistance to this fungal pathogen. classification of 163 isolates for four putative isozyme systems, a colony color dimorphism and 20 ribosomal dna restriction fragment length variants revealed 49 different multilocus phenotypes (haplotypes). the six most common haplotypes differed significantly in pathogenicity. genetic analyses of the data indicated that effe ... | 1989 | 2759420 |
| symptoms of scald disease induced by toxic metabolites of rhynchosporium secalis. | | 1971 | 5553669 |
| the race-specific elicitor, nip1, from the barley pathogen, rhynchosporium secalis, determines avirulence on host plants of the rrs1 resistance genotype. | nip1, a small phytotoxic protein secreted by the barley pathogen rhynchosporium secalis, is a race-specific elicitor of defense responses in barley cultivars carrying the resistance gene, rrs1. co-inoculation employing spores from a virulent fungal race together with the nip1 protein converted the phenotype of the interaction from compatible to incompatible only on rrs1-containing plants. in addition, transformation of a virulent fungal race with the nip1 gene yielded avirulent transformants. th ... | 1995 | 7556057 |
| cultivar-specific elicitation of barley defense reactions by the phytotoxic peptide nip1 from rhynchosporium secalis. | resistance of barley to the phytopathogenic fungus, rhynhosporium secalis race us238.1, was found to be controlled by resistance gene rrs1, which segregated in a manner characteristics for a codominant gene. prhv-1, a thaumatin-like pathogenesis-related protein, was shown to be encoded by a gene family on chromosome 1. as part of the barley defense response, significant accumulation of prhv-1 and peroxidase transcripts was induced early during pathogenesis in two rrs1 cultivars but not or to a l ... | 1993 | 8118056 |
| identification of rapd markers linked to a rhynchosporium secalis resistance locus in barley using near-isogenic lines and bulked segregant analysis. | three hundred random sequence 10-mer primers were used to screen a pair of near-isogenic lines of barley and their donor parent for markers linked to genes conferring resistance to rhynchosporium secalis. one primer was identified which reproducibly generated a product, sc10-65-h400, from the donor parent and the rhynchosporium-resistant near-isogenic line but not from the recurrent parent. segregation analysis on a barley doubled haploid population and examination of a further three near-isogen ... | 1993 | 8376177 |
| transformation of the plant pathogenic fungus, rhynchosporium secalis. | the barley leaf scald fungus, rhynchosporium secalis, was transformed to hygromycin-b and phleomycin resistance using the hph gene from e. coli and the ble gene from streptoalloteichus hindustanus under the control of aspergillus nidulans promoter and terminator sequences. plasmid dna was introduced into fungal protoplasts by peg/cacl2 treatment. transformation frequencies varied from 59 to 493 transformants per 10 microg of dna and 5 x 10(7) protoplasts. the antibiotic-resistant phenotype appea ... | 1996 | 8662199 |
| differential expression of pathogen-responsive genes encoding two types of glycine-rich proteins in barley. | gene-specific probes (3' ends of cdnas) were obtained from barley cdnas encoding two types of glycine-rich proteins: hvgrp2, characterized by a cytokeratin-like and a cysteine-rich domain, and hvgrp3, whose main feature was an rna-binding domain. expression of genes hvgrp2 and hvgrp3, which are present at one (or two) copies per haploid genome, was ubiquitous and gene hvgrp3 was under light/darkness modulation. cold treatment increased hvgrp2 and hvgrp3 mrna levels. methyl jasmonate (10 microm) ... | 1997 | 9106504 |
| staining paraffin embedded sections of scald of barley before paraffin removal. | staining of paraffin embedded sections with periodic acid-schiff reagent and fast green before paraffin removal resulted in differentiation of barley seed and leaf tissue from fungal structures of rhynchosporium secalis. crystal violet, toluidine blue o and antiline blue also successfully stained fungal structures of r. secalis in barley leaf tissues. staining of embedded sections before paraffin removal allows simple processing of a series of sections, saves time and reduces solvent consumption ... | 1997 | 9290905 |
| fungal avirulence genes: structure and possible functions. | avirulence (avr) genes exist in many fungi that share a gene-for-gene relationship with their host plant. they represent unique genetic determinants that prevent fungi from causing disease on plants that possess matching resistance (r) genes. interaction between elicitors (primary or secondary products of avr genes) and host receptors in resistant plants causes induction of various defense responses often involving a hypersensitive response. avr genes have been successfully isolated by reverse g ... | 1998 | 9756710 |
| isolation and characterization of alpha-tubulin genes from septoria tritici and rhynchosporium secalis, and comparative analysis of fungal alpha-tubulin sequences. | the alpha-tubulin genes from septoria tritici and rhynchosporium secalis have been cloned and sequenced. the predicted amino acid sequence and intron structure showed strong homology with other known filamentous fungal alpha-tubulins. comparison of sixteen fungal alpha-tubulin sequences based on amino acid sequence homology and intron structure identified five groups of proteins. group 1 consists of filamentous fungi, including s. tritici and r. secalis, the dimorphic fungus histoplasma capsulat ... | 1998 | 9829778 |
| heterologous expression of the avirulence gene product, nip1, from the barley pathogen rhynchosporium secalis. | nip1, the product of the avirulence gene avrrrs1 from rhynchosporium secalis, a fungal pathogen of barley, is a small secreted cysteine-rich protein. this protein is essential for the specific recognition of the fungus by host plants carrying the complementary resistance gene rrs1. different heterologous expression systems were tested to produce sufficient quantities of nip1 to allow its utilization in receptor identification and isolation. in addition, protein amounts higher than those produced ... | 1999 | 10497070 |
| sterol glycosides and cerebrosides accumulate in pichia pastoris, rhynchosporium secalis and other fungi under normal conditions or under heat shock and ethanol stress. | the occurrence of glycolipids such as sterol glycosides, acylated sterol glycosides, cerebrosides and glycosyldiacylglycerols was examined in the three yeast species candida albicans, pichia pastoris and pichia anomala, as well as in the six fungal species sordaria macrospora, pyrenophora teres, ustilago maydis, acremonium chrysogenum, penicillium olsonii and rhynchosporium secalis. cerebroside was found in all organisms tested, whereas acylated sterol glycosides and glycosyldiacylglycerols were ... | 2001 | 11378896 |
| construction of a yac library from barley cultivar franka and identification of yac-derived markers linked to the rh2 gene conferring resistance to scald (rhynchosporium secalis). | the rh2 resistance gene of barley (hordeum vulgare) confers resistance against the scald pathogen (rhynchosporium secalis). a high-resolution genetic map of the rh2 region on chromosome i (7h) was established by the use of molecular markers. tightly linked markers from this region were used to screen existing and a newly constructed yeast artificial chromosome (yac) library of barley cv. franka composed of 45,000 clones representing approximately two genome equivalents. corresponding yac clones ... | 2001 | 11768206 |
| stimulation of barley plasmalemma h+-atpase by phytotoxic peptides from the fungal pathogen rhynchosporium secalis. | a small family of necrosis-inducing peptides has been identified as virulence factors of rhynchosporium secalis, a fungal pathogen of barley (hordeum vulgare l.) two members of this family, nip1 and nip3, were found to stimulate the phosphohydrolyzing activity of the mg2+-dependent, k+-stimulated h+-atpase of plasma membrane vesicles isolated from barley leaves by partitioning in an aqueous two-phase system. stimulation of enzyme activity was saturated by 10 to 15 [mu]m fungal protein. another m ... | 1993 | 12231685 |
| isolation of fungal cell wall degrading proteins from barley (hordeum vulgare l.) leaves infected with rhynchosporium secalis. | proteins with antifungal activity towards rhynchosporium secalis conidia were isolated from the intercellular washing fluid (iwf) of barley leaves. the active components were purified by high-performance liquid chromatography under conditions that maintained biological activity. five major barley iwf proteins deleterious to the cell wall of viable r. secalis conidia were isolated and identified by a combination of n-terminal amino acid sequencing, peptide mapping, and determination of mass and i ... | 2002 | 12437301 |
| role of reactive oxygen species in the response of barley to necrotrophic pathogens. | the interactions between hordeum vulgare(barley) and two fungal necrotrophs, rhynchosporium secalis and pyrenophora teres (causal agents of barley leaf scald and net blotch), were investigated in a detached-leaf system. an early oxidative burst specific to epidermal cells was observed in both the susceptible and resistant responses to r. secalis, and later on, a second susceptible-specific burst was observed. time points of the first and the second burst correlated closely with pathogen contact ... | 2003 | 12768351 |
| resistance genes in barley (hordeum vulgare l.) and their identification with molecular markers. | current information on barley resistance genes available from scientific papers and on-line databases is summarised. the recent literature contains information on 107 major resistance genes (r genes) against fungal pathogens (excluding powdery mildew), pathogenic viruses and aphids identified in hordeum vulgare accessions. the highest number of resistance genes was identified against puccinia hordei, rhynchosporium secalis, and the viruses baymv and bammv, with 17, 14 and 13 genes respectively. ... | 2003 | 12923305 |
| solution structure of the plant disease resistance-triggering protein nip1 from the fungus rhynchosporium secalis shows a novel beta-sheet fold. | activation of the disease resistance response in a host plant frequently requires the interaction of a plant resistance gene product with a corresponding, pathogenderived signal encoded by an avirulence gene. the products of resistance genes from diverse plant species show remarkable structural similarity. however, due to the general paucity of information on pathogen avirulence genes the recognition process remains in most cases poorly understood. nip1, a small protein secreted by the fungal ba ... | 2003 | 12944393 |
| further evidence for sexual reproduction in rhynchosporium secalis based on distribution and frequency of mating-type alleles. | rhynchosporium secalis, the causal agent of scald on barley, is thought to be exclusively asexual because no teleomorph has been found. partial sequences of the hmg-box and alpha-domain of rhynchosporium secalis isolates were identified and used to develop a pcr assay for the mating-type locus. pcr amplification of only one of these two domains was possible in each strain, suggesting that r. secalis has a mat organization that is similar to other known heterothallic fungi. a multiplex pcr with p ... | 2003 | 14516764 |
| isolation and characterisation of the mating-type (mat) locus from rhynchosporium secalis. | the mating-type ( mat) genes from rhynchosporium secalis were isolated using pcr-based methods. characterisation of the mat idiomorphs suggests that r. secalis is closely related to the discomycetes pyrenopeziza brassicae and tapesia yallundae in terms of sequence and mat locus gene composition. the mat1-2 idiomorph contains a single gene encoding a protein with a high-mobility group (hmg) dna-binding domain. the mat1-1 idiomorph contains two genes, one encoding a protein with a hmg domain and t ... | 2003 | 14517690 |
| differential defense reactions in leaf tissues of barley in response to infection by rhynchosporium secalis and to treatment with a fungal avirulence gene product. | expression of defense-associated genes was analyzed in leaf tissues of near-isogenic resistant and susceptible barley cultivars upon infection by rhynchosporium secalis. the genes encoding pathogenesis-related (pr) proteins pr-1, pr-5, and pr-9 are specifically expressed in the mesophyll of resistant plants, whereas a germin-like protein (oxolp) is synthesized in the epidermis irrespective of the resistance genotype. restriction-mediated differential display was employed to identify additional e ... | 2003 | 14558691 |
| dynamics of rhynchosporium secalis pathotypes in relation to barley cultivar resistance. | rhynchosporium secalis isolates e97-2 and h97-2, represented the major pathotypes in populations on barley in alberta, canada, but differed widely in their virulence. following greenhouse co-inoculation with the two pathotypes, e97-2, originally isolated from resistant cv. 'cdc earl', predominated over h97-2, isolated from the susceptible cv. 'harrington', from the first to the last of four infection cycles on both 'cdc earl' and 'harrington'. these results indicated that the host can rapidly in ... | 2003 | 15000249 |
| molecular population genetic analysis differentiates two virulence mechanisms of the fungal avirulence gene nip1. | deletion or alteration of an avirulence gene are two mechanisms that allow pathogens to escape recognition mediated by the corresponding resistance gene in the host. we studied these two mechanisms for the nip1 avirulence gene in field populations of the fungal barley pathogen rhynchosporium secalis. the product of the avirulence gene, nip1, causes leaf necrosis and elicits a defense response on plants with the rrs1 resistance gene. a high nip1 deletion frequency (45%) was found among 614 isolat ... | 2004 | 15497404 |
| resistance to barley scald (rhynchosporium secalis) in the ethiopian donor lines 'steudelli' and 'jet', analyzed by partial least squares regression and interval mapping. | the resistance of barley (hordeum vulgare l.) to rhynchosporium secalis (scald) has been investigated in two crosses between the susceptible cv. 'ingrid' and two resistant ethiopian landraces, 'steudelli' and 'jet'. doubled haploids were inoculated in replicated tests using two isolates of r. secalis, '4004' and 'wrs1872'. expression of resistance differed widely between replicated tests. aflp, ssr and rflp markers were used to develop chromosome maps. results have been analysed using partial le ... | 2004 | 15660977 |
| ab-qtl analysis in spring barley. i. detection of resistance genes against powdery mildew, leaf rust and scald introgressed from wild barley. | the objective of this study was to map new resistance genes against powdery mildew (blumeria graminis f. sp. hordei l.), leaf rust (puccinia hordei l.) and scald [rhynchosporium secalis (oud.) j. davis] in the advanced backcross doubled haploid (bc2dh) population s42 derived from a cross between the spring barley cultivar 'scarlett' and the wild barley accession isr42-8 (hordeum vulgare ssp. spontaneum). using field data of disease severity recorded in eight environments under natural infestatio ... | 2005 | 15902395 |
| rhynchosporoside, a host-selective toxin produced by rhynchosporium secalis, the causal agent of scald disease of barley. | rhynchosporoside, a phytotoxic compound, has been isolated from cultures of rhynchosporium secalis, the causal agent of scald disease of barley. the toxin is a cello-bioside of 1,2-propanediol. the compound may play some role in symptom expression because it was isolated from diseased plants in concentrations similar to those that could cause symptoms in toxin-treated plants. the toxin causes leaf tip and marginal necrosis and subsequent chlorosis of the entire leaf. the toxin affects only certa ... | 1978 | 16592563 |
| genetic diversity of rhynchosporium secalis in tunisia as revealed by pathotype, aflp, and microsatellite analyses. | genetic variability among 122 rhynchosporium secalis isolates collected from barley in three regions of tunisia was investigated using host differentials, amplified fragment length polymorphism (aflp), and microsatellite markers. the isolates were collected from a widely grown scald-susceptible barley cultivar rihane and a range of local landrace cultivars in geographically distinct regions with different agroclimatic conditions. pathotypic diversity (the proportion of unique pathotypes) was hig ... | 2007 | 17429759 |
| a single binding site mediates resistance- and disease-associated activities of the effector protein nip1 from the barley pathogen rhynchosporium secalis. | the effector protein nip1 from the barley (hordeum vulgare) pathogen rhynchosporium secalis specifically induces the synthesis of defense-related proteins in cultivars of barley expressing the complementary resistance gene, rrs1. in addition, it stimulates the activity of the barley plasma membrane h(+)-atpase in a genotype-unspecific manner and it induces necrotic lesions in leaf tissues of barley and other cereal plant species. nip1 variants type i and ii, which display quantitative difference ... | 2007 | 17478637 |
| the origin and colonization history of the barley scald pathogen rhynchosporium secalis. | the origins of pathogens and their past and present migration patterns are often unknown. we used phylogenetic haplotype clustering in conjunction with model-based coalescent approaches to reconstruct the genetic history of the barley leaf pathogen rhynchosporium secalis using the avirulence gene nip1 and its flanking regions. our results falsify the hypothesis that r. secalis emerged in association with its host during the domestication of barley 10,000 to 15,000 years ago in the fertile cresce ... | 2007 | 17584226 |
| rapid speciation following recent host shifts in the plant pathogenic fungus rhynchosporium. | agriculture played a significant role in increasing the number of pathogen species and in expanding their geographic range during the last 10,000 years. we tested the hypothesis that a fungal pathogen of cereals and grasses emerged at the time of domestication of cereals in the fertile crescent and subsequently speciated after adaptation to its hosts. rhynchosporium secalis, originally described from rye, causes an important disease on barley called scald, although it also infects other species ... | 2008 | 18384659 |
| the complex quantitative barley-rhynchosporium secalis interaction: newly identified qtl may represent already known resistance genes. | two barley populations, i.e. 135 doubled haploid (dh) lines of the cross 'igri' (rrs1) x 'triton' (rrs1) (i x t) and 76 dh lines of the cross 'post' x 'vixen' (both rrs1) (p x v), were analysed to identify qtl for rhynchosporium secalis resistance independent of the rrs1 locus by using the single spore r. secalis isolate 271 (rrs1-virulent). a major qtl with its positive allele derived from cv. 'triton' was detected in the i x t population on chromosome 2hs explaining almost 80% of the phenotypi ... | 2008 | 18806993 |
| resistance to scald (rhynchosporium secalis) in barley (hordeum vulgare) studied by near-isogenic lines: i. markers and differential isolates. | abstract near-isogenic lines (nils) with resistance for scald in seventh generation backcross with 'ingrid' as recurrent parent (rp) were tested with seven differential isolates of rhynchosporium secalis in norway and canada. nils of 'turk', 'brier', 'ci 8162', 'la mesita', 'hispont', 'atlas 46', 'modoc', 'hudson', 'abyssinian', 'steudelli', and 'ci 2222' also were evaluated for field reactions. the genetic characterization of the nils (degree of isogeneity with ingrid) and with each other was c ... | 2002 | 18943266 |
| asexual genetic exchange in the barley pathogen rhynchosporium secalis. | abstract the causal agent of barley scald, rhynchosporium secalis, is a haploid anamorphic ascomycete with no known sexual stage. nevertheless, a high degree of genetic variation has been observed in fungal populations on commercial barley cultivars and parasexuality has been suggested to contribute to this variation. in order to test whether asexual genetic exchange can occur, isolates of r. secalis were transformed to hygromycin b resistance or phleomycin resistance. mixtures of transformants ... | 2007 | 18943585 |
| application of real-time and multiplex polymerase chain reaction assays to study leaf blotch epidemics in barley. | abstract leaf blotch, caused by rhynchosporium secalis, was studied in a range of winter barley cultivars using a combination of traditional plant pathological techniques and newly developed multiplex and real-time polymerase chain reaction (pcr) assays. using pcr, symptomless leaf blotch colonization was shown to occur throughout the growing season in the resistant winter barley cv. leonie. the dynamics of colonization throughout the growing season were similar in both leonie and vertige, a sus ... | 2007 | 18943648 |
| differential selection on rhynchosporium secalis during parasitic and saprophytic phases in the barley scald disease cycle. | abstract competition among eight rhynchosporium secalis isolates was assessed during parasitic and saprophytic phases of the disease cycle in field experiments conducted at two locations and over two growing seasons. the eight isolates were inoculated onto six barley populations exhibiting varying degrees of resistance. microsatellite analysis of 2,866 isolates recovered from the field experiments showed significant, and sometimes opposite, changes in the frequencies of r. secalis genotypes duri ... | 2006 | 18943958 |
| global hierarchical gene diversity analysis suggests the fertile crescent is not the center of origin of the barley scald pathogen rhynchosporium secalis. | a total of 1,366 rhynchosporium secalis isolates causing scald on barley, rye, and wild barley (hordeum spontaneum) were assayed for restriction fragment length polymorphism loci, dna fingerprints, and mating type, to characterize global genetic structure. the isolates originated from 31 field populations on five continents. hierarchical analysis revealed that more than 70% of the total genetic variation within regions was distributed within a barley field. at the global level, only 58% of the t ... | 2006 | 18944049 |
| the genetic structure of field populations of rhynchosporium secalis from three continents suggests moderate gene flow and regular recombination. | abstract restriction fragment length polymorphism (rflp) markers were used to compare the genetic structure of field populations of rhynchosporium secalis from barley. a total of 543 isolates representing 8 field populations were sampled from australia, california, finland, and norway. gene and genotype diversity were high in all populations. nei's average gene diversity across seven rflp loci was 0.513. hierarchical gene diversity analysis showed that 9% of the total genetic variability was dis ... | 2000 | 18944512 |
| histopathological study of barley cultivars resistant and susceptible to rhynchosporium secalis. | abstract differences in the penetration process by rhynchosporium secalis were compared in resistant and susceptible barley cultivars at the seedling stage. percent penetration and percent host cell wall alteration (hcwa) differed significantly among cultivars and isolates as revealed by light microscopy. based on these two variables, the cultivars were statistically separated into two groups that corresponded to their disease reactions. the resistant cultivars, johnston and cdc guardian, showed ... | 2000 | 18944577 |
| genetic structure of rhynchosporium secalis in australia. | abstract restriction fragment length polymorphism (rflp) markers were used to determine the genetic structure of australian field populations of the barley scald pathogen rhynchosporium secalis. fungal isolates were collected by hierarchical sampling from five naturally infected barley fields in different geographic locations during a single growing season. genetic variation was high in australian r. secalis populations. among the 265 fungal isolates analyzed, 214 distinct genotypes were identif ... | 1999 | 18944675 |
| phylogeographical analyses reveal global migration patterns of the barley scald pathogen rhynchosporium secalis. | a phylogeographical analysis of the scald pathogen rhynchosporium secalis was conducted using nuclear dna sequences from two neutral restriction fragment length polymorphism loci and the mating-type idiomorphs. approximately 500 isolates sampled from more than 60 field populations from five continents were analysed to infer migration patterns and the demographic history of the fungus. migration rates among continents were generally low, consistent with earlier reports of significant population s ... | 2009 | 19076278 |
| molecular evidence for recent founder populations and human-mediated migration in the barley scald pathogen rhynchosporium secalis. | rhynchosporium secalis is an important pathogen of barley globally. fourteen polymorphic microsatellites were analyzed for 1664 r. secalis isolates sampled from 37 field populations to infer their demographic history. the results falsified the hypothesis that r. secalis co-evolved with its barley host in the middle east. populations from scandinavia had significantly higher allelic diversities, the greatest number of private alleles and the highest genotypic diversities. all but three of the ana ... | 2009 | 19289174 |
| hyphal cell walls from the plant pathogen rhynchosporium secalis contain (1,3/1,6)-beta-d-glucans, galacto- and rhamnomannans, (1,3;1,4)-beta-d-glucans and chitin. | a procedure has been developed for the isolation of cell walls from the hyphae of the causal agent for barley leaf scald, rhynchosporium secalis (oudem) j.j. davis. based primarily on monosaccharide linkage analysis, but also on the limited use of linkage-specific glucan hydrolases and solvent fractionation, the walls consist predominantly of (1,3/1,6)-beta-d-glucans, (1,3;1,4)-beta-d-glucans, galactomannans of (1,2;1,6)-manp residues and (1,5)-galactofuranosyl [(1,5)-galf] side chains, rhamnoma ... | 2009 | 19496815 |
| fine mapping, physical mapping and development of diagnostic markers for the rrs2 scald resistance gene in barley. | the rrs2 gene confers resistance to the fungal pathogen rhynchosporium secalis which causes leaf scald, a major barley disease. the rrs2 gene was fine mapped to an interval of 0.08 cm between markers 693m6_6 and p1d23r on the distal end of barley chromosome 7hs using an atlas (resistant) x steffi (susceptible) mapping population of 9,179 f(2)-plants. the establishment of a physical map of the rrs2 locus led to the discovery that rrs2 is located in an area of suppressed recombination within this ... | 2009 | 19789848 |
| pathotype and microsatellite analyses reveal new sources of resistance to barley scald in tunisia. | we examined the variation and relationships between pathogenicity and a microsatellite-based haplotype in 79 tunisian rhynchosporium secalis isolates that were collected from the most commonly cultivated barley populations in tunisia, rihane cv. and local landraces, with the goal of finding genes that might be used to monitor resistance to scald. isolates could be classified into three distinct virulence groups based on artificial inoculation of 19 differential cultivars with known scald resista ... | 2010 | 20180856 |
| hypharea--automated analysis of spatiotemporal fungal patterns. | in phytopathology quantitative measurements are rarely used to assess crop plant disease symptoms. instead, a qualitative valuation by eye is often the method of choice. in order to close the gap between subjective human inspection and objective quantitative results, the development of an automated analysis system that is capable of recognizing and characterizing the growth patterns of fungal hyphae in micrograph images was developed. this system should enable the efficient screening of differen ... | 2010 | 20863593 |
| new insights into the infection process of rhynchosporium secalis in barley using gfp. | through the use of a rhynchosporium secalis isolate transformed with the green fluorescent protein gene and laser scanning confocal microscopy (lscm), fungal development during the r. secalis/barley interaction was analysed. each infection stage was investigated from 0.5h to 14 days post-inoculation (p.i.) with extensive sampling within the first 48 h p.i. early germination events were observed that had not been previously described. a specific time of germination was noted, with germ tube forma ... | 2010 | 20955811 |
| zymoseptoria gen. nov.: a new genus to accommodate septoria-like species occurring on graminicolous hosts. | the mycosphaerella complex is both poly- and paraphyletic, containing several different families and genera. the genus mycosphaerella is restricted to species with ramularia anamorphs, while septoria is restricted to taxa that cluster with the type species of septoria, s. cytisi, being closely related to cercospora in the mycosphaerellaceae. species that occur on graminicolous hosts represent an as yet undescribed genus, for which the name zymoseptoria is proposed. based on the 28s nrdna phyloge ... | 2011 | 22025804 |