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Esmaeil Basavand Nargues Falahi Charkhabi Pejman Khodaygan Heshmatollah Rahimian 《Forest Pathology》2021,51(1):e12655
Lawson cypress (Chamaecyparis lawsoniana), an important landscape tree, is widely planted in gardens and parks throughout Iran. Crown gall disease on Lawson cypress trees was observed in Sari and Juybar Counties, Mazandaran province, northern Iran, in 2017. Isolation from galls on potato dextrose agar (PDA) containing CaCO3 yielded bacterial colonies, the predominant types of which were purified and selected for characterization. The isolates were Gram‐negative, oxidase positive, able to grow in 2% NaCl and produced 3‐ketolactose. They hydrolysed esculin, casein and arbutin but not starch, gelatin or Tween 80. Two representative isolates were selected for PCR amplification and sequencing of DNA gyrase subunit B (gyrB) gene. In the phylogenetic tree based on the partial sequence of the gyrB gene, isolates KH1 and KH2 clustered with Agrobacterium pusense. The pathogenicity of all isolates was confirmed by inoculation on Jimsonweed (Datura stramonium) and carrot discs (Daucus carota). Confirmation of the presence of genes involved in pathogenicity was made by performing PCR with the virD2A/virD2C and VCF/VCR primer pairs which resulted in amplification of the expected 224 and 730 bp fragments in all studied isolates, respectively. A. pusense was therefore identified as the causal agent of crown and stem gall of Lawson cypress. This appears to be the first report on the natural occurrence of crown gall disease on Lawson cypress and the first record of a plant disease caused by A. pusense. 相似文献
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Allahverdipour Tohid Shahryari Fatemeh Falahi Charkhabi Nargues 《European journal of plant pathology / European Foundation for Plant Pathology》2021,161(4):783-797
European Journal of Plant Pathology - A bacterial disease of walnut (Juglans regia) has been observed in northwestern Iran during the summer of 2018 with symptoms similar to the shallow bark canker... 相似文献
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Nargues Falahi Charkhabi Masoud Shams-bakhsh Heshmat Rahimian 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(3):303-310
To investigate the variability of Brenneria nigrifluens, the casual agent of shallow bark canker of Persian walnut (Juglans regia L.), a collection of 24 strains isolated from five geographic regions, was analyzed by means of three marker systems, repetitive
polymerase chain reaction (rep-PCR), insertion sequence (IS50)-PCR and random amplified polymorphic DNA (RAPD). Cluster analysis
was performed using UPGMA. Strains were differentiated into 6 groups at about 80% similarity according to geographic regions.
This is possibly due to cultivation of Persian walnut being mainly based on the ecotype and/or local seedlings that have become
adapted to particular environments and so have allowed selection of different B. nigrifluens populations. The results of this study showed that the four rep-PCR primers produced 75 products of which 73.3% were polymorphic,
eight RAPD primers produced 146 fragments of which 74.6% were polymorphic and IS50 produced 32 fragments of which 93.75% were
polymorphic. The usefulness of each system was examined in terms of polymorphism information content (PIC) and marker index
(MI). The highest MI was observed for IS50-PCR (21.11) followed by RAPD (7.85), and rep-PCR (6.92). The Mantel test identified
significant correlation between the similarity coefficients calculated from them. Among the molecular markers tested, IS50-PCR
appears to be a more suitable marker for fingerprinting and assessing genetic relationships among B. nigrifluens strains. This is the first study on genetic diversity of B. nigrifluens. The results can have a bearing on the choice of disease management strategies. 相似文献
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