Movement of the bacterial blight pathogen Erwinia psidii in guava varieties differing in susceptibility
4
Citation
32
Reference
10
Related Paper
Citation Trend
The present investigations regarding the identification of resistance resources of bacterial blight in common bean were conducted in the SKUAST-K during 2009 to 2010. Study showed that the infected seeds harbour the pathogen beyond the next sowing season. The viability of pathogen on infected seeds decreased with time. Out of forty one bean genotypes screened against the pathogen under conditions of artificial inoculation, 2 were categorised as resistant, 2 as moderately resistant, 21 as moderately susceptible, whereas 13 genotypes were found susceptible and only three genotypes were highly susceptible.
Cite
Citations (1)
The leaf blight of walnut in Hotan of Xinjiang was investigated and the specimens were collected in October 2010.The pathogen was isolated from the diseased tissue,through purification,identification,and the check according to Koch's postulates,the pathogen caused the leaf blight of walnut was obtained.Based on the morphological characteristics and the molecular identification of rDNA-ITS,the pathogen was identified as Alternaria alternata.
Fungal pathogen
Identification
Cite
Citations (0)
The phylogenetic relationships of the type strains of 16 Erwinia species were investigated by performing a comparative analysis of the sequences of the 16S rRNA genes of these organisms. The sequence data were analyzed by the neighbor-joining method, and each branch was supported by moderate bootstrap values. The phylogenetic tree and sequence analyses confirmed that the genus Erwinia is composed of species that exhibit considerable heterogeneity and form four clades that are intermixed with members of other genera, such as Escherichia coli, Klebsiella pneumoniae, and Serratia marcescens. Cluster I includes the type strains of Erwinia herbicola, Erwinia millltiae, Erwinia ananas, Erwinia uredovora, and Erwinia stewartii and corresponds to Dye's herbicola group. Cluster II consists of Erwinia persicinus, Erwinia rhapontici, Erwinia amylovora, and Erwinia cypripedii. Cluster III consists of Erwinia carotovora subspecies and Erwinia chrysanthemi and is characterized by the production of pectate lyases and cellulases. Erwinia salicis, Erwinia rubrifaciens, and Erwinia nigrifluens form the cluster that is most distantly related to other Erwinia species. The data from the sequence analyses are discussed in the context of biochemical and DNA-DNA hybridization data.
Subspecies
Cite
Citations (120)
Abstract Disease surveys conducted in Trinidad between 1985—1987 showed that Cassava Bacterial Blight (CBB) is present in all but one county of the country with disease severity ratings varying from 1—5 depending on day/night temperatures. Field and greenhouse screening identified varieties such as Point Fortin fine leaf and CMC 40 as being resistant whereas M col 22 was moderately resistant to susceptible. Using a combination of antiserum produced to whole cells of Xanthomonas campestris pv. manibotis and a broth enrichment technique, dissemination of the pathogen by flood water was confirmed. The pathogen was detected at distances of up to 300 meters from infected fields. The significance of this mode of pathogen dissemination in initiating primary infection in Trinidad is discussed.
Xanthomonas
Cite
Citations (6)
American chestnuts (Castanea dentata), effectively eliminated from eastern North America by chestnut blight in the twentieth century, are the subject of multiple restoration efforts. Screening individual trees (or tree types) for blight resistance is a critical step in all of these programs. Traditional screening involves inoculating stems of >3-year-old trees with the blight fungus (Cryphonectria parasitica), then measuring resulting cankers a few months later. A quicker, nondestructive, quantitative assay, usable on younger plants, would enhance restoration efforts by speeding the screening process. The assay presented here meets these requirements by inoculating excised leaves with the blight fungus and measuring resulting necrotic lesions. Leaves can be collected from few-month-old seedlings or fully mature trees, and results are measured after less than a week. Leaves from several lines of both American and Chinese chestnuts were inoculated, as well as the congener Allegheny chinquapin, and experimental leaf assay results correlate well with stem assay results from these species. Inoculations with virulent and hypovirulent blight fungi strains also showed relative patterns similar to traditional inoculations. Given the correlations to established stem assay results, this procedure could be a valuable tool to quickly evaluate blight resistance in American chestnut trees used for restoration.
Chestnut Blight
Cryphonectria
Cite
Citations (22)
Fungal pathogen
Cite
Citations (1)
Several strains of the genus Erwinia, which were isolated in Japan from pear trees with necrotic symptoms that resembled fire blight, and tentatively identified as Erwinia amylovora, were reinvestigated for their relationship to the fire blight pathogen. These isolates produced ooze on slices of immature pears and were mucoid on MM2Cu agar plates, but did not synthesize levan and did not give the expected PCR signals with several primer pairs specific for Erwinia amylovora. The isolates tested positive with PCR primers designed to detect the novel pear pathogen Erwinia pyrifoliae, which was isolated from Nashi pear trees in South Korea. The nucleotide sequence analysis of a DNA fragment preceding the gene cluster for exopolysaccharide synthesis revealed a closer relationship to Erwinia pyrifoliae than to Erwinia amylovora. Plasmid profiles, protein patterns and genomic DNA analysed by PFGE after XbaI and SpeI digestion were different than Erwinia amylovora. Experiments with strains of Erwinia amylovora isolated from raspberry (Rubus sp.), Erwinia mallotivora and Enterobacter pyrinus also did not reveal a relationship between these bacteria and the Japanese Erwinia strains. The latter are not identical to Erwinia pyrifoliae, but possess many similar features to this pathogen that causes Asian pear blight. It is concluded that pathogenic bacteria isolated in Japan from pear trees with symptoms resembling fire blight are possibly different from Erwinia amylovora.
Fire blight
Pantoea agglomerans
Cite
Citations (69)
Genotypic characterization, based on the analysis of restriction fragment length polymorphism of the recA gene fragment PCR product ( recA PCR-RFLP), was performed on members of the former Erwinia genus. PCR primers deduced from published recA gene sequences of Erwinia carotovora allowed the amplification of an approximately 730 bp DNA fragment from each of the 19 Erwinia species tested. Amplified recA fragments were compared using RFLP analysis with four endonucleases ( Alu I, Hin fI, Tas I and Tru 1I), allowing the detection of characteristic patterns of RFLP products for most of the Erwinia species. Between one and three specific RFLP groups were identified among most of the species tested ( Erwinia amylovora , Erwinia ananas , Erwinia cacticida , Erwinia cypripedii , Erwinia herbicola , Erwinia mallotivora , Erwinia milletiae , Erwinia nigrifluens , Erwinia persicina , Erwinia psidii , Erwinia quercina , Erwinia rhapontici , Erwinia rubrifaciens , Erwinia salicis , Erwinia stewartii , Erwinia tracheiphila , Erwinia uredovora , Erwinia carotovora subsp. atroseptica , Erwinia carotovora subsp. betavasculorum , Erwinia carotovora subsp. odorifera and Erwinia carotovora subsp. wasabiae ). However, in two cases, Erwinia chrysanthemi and Erwinia carotovora subsp. carotovora , 15 and 18 specific RFLP groups were detected, respectively. The variability of genetic patterns within these bacteria could be explained in terms of their geographic origin and/or wide host-range. The results indicated that PCR-RFLP analysis of the recA gene fragment is a useful tool for identification of species and subspecies belonging to the former Erwinia genus, as well as for differentiation of strains within E. carotovora subsp. carotovora and E. chrysanthemi.
Cite
Citations (142)
Bacterial soft rot causes great loss to the growth of butterfly orchid.Erwinia chrysanthemi and Erwinia carotovora subsp.carotovora are the main bacterial pathogen led to rot disease.In the study,the mole-cular technology had been primarily established to detect E.chrysanthemi,the potential serious quarantine pathogen.The specific primers was designed to the detection of E.chrysanthemi and real-time fluorescent PCR method could achieve high sensitivity.
Cite
Citations (0)
API 20E and API 50CHE systems (72 phenotypic tests) were applied to a total of 529 strains, including 421 strains belonging to 21 different Erwinia species, 66 Enterobacter agglomerans strains, 18 Escherichia adecarboxylata strains, and 24 strains of 16 other enterobacteria. The results were analyzed numerically by using the Gower similarity coefficient and the unweighted average linkage method. The named Erwinia strains were distributed over 27 phena, some of which also contained strains received as Enterobacter agglomerans. Strains of Erwinia amylovora, Erwinia chrysanthemi, Erwinia cypripedii, Erwinia mallotivora, Erwinia nigrifluens, Erwinia paradisiaca, Erwinia quercina, Erwinia rubrifaciens, Erwinia salicis, Erwinia stewartii, and Escherichia adecarboxylata constitute separate phena. Erwinia carotovora, Erwinia chrysanthemi, and Erwinia rhapontici are heterogeneous, but distinct from each other and from the other phena. The type strains of Erwinia herbicola, Enterobacter agglomerans, and Erwinia milletiae fall into one phenon, and strains of Erwinia ananas and Erwinia uredovora are in a single phenon. Obviously misnamed Erwinia herbicola and Enterobacter agglomerans strains can be assigned to other species, such as Erwinia cypripedii, Erwinia ananas, Erwinia rhapontici, Rahnella aquatilis, Enterobacter sakazakii, Escherichia adecarboxylata, and Serratia marcescens or to as-yet-unnamed phena. Three Erwinia carnegieana strains, but not the type strain, form one phenon. Erwinia dissolvens and Erwinia nimipressuralis should be allocated to Enterobacter. Our results confirm the heterogeneous taxonomic structure of the genus Erwinia.
Pantoea agglomerans
Blackleg
Cite
Citations (86)