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Farahani A.A.,Islamic Azad University at Tehran | Rakhshandehroo F.,Islamic Azad University at Tehran | Shahraeen N.,Plant Pests and Diseases Research Institute
Journal of Plant Pathology | Year: 2014

Tobacco mosaic virus (TMV) is distributed worldwide in all areas where horticultural crops are grown. In 2011, commercial cabbage (Brassica oleracea var. capitata) fields in the Savejbolagh district of Alburz province in Iran showed mosaic and malformations on young leaves. Based on the symptoms and previous virus survey outputs in the region (Alishiri et al., 2013), the involvement of tobamoviruses in disease aetiology was suspected. A total of 55 symptomatic cabbage leaf samples were collected from different fields and tested by DAS-ELISA using specific TMV antisera (Bioreba, Switzerland). TMV was detected in 58% of the samples tested. Its presence was confirmed by RT-PCR using specific primers designed in the coat protein gene (Letschert et al., 2002) with amplification of a 694 bp fragment from ELISA-positive but not from ELISA-negative control samples. The RT-PCR product of a TMV isolate was sequenced and the nucleotide sequence was deposited in GenBank as accession No. KF527475. BLAST analysis showed 90% and 100% identity with the coat protein gene of other TMV isolates (AF516913, AJ429078, AY360447, HE818417) at the nucleotide and amino acid levels, respectively. A host range trial using infected cabbage leaf extracts as inoculum revealed characteristic TMV symptoms on mechanically inoculated Chenopodium amaranticolor, Nicotiana tabacum cv. Samsun and Solanum lycopersicum. TMV isolates induced chlorotic local lesions on inoculated leaves of C. amaranticolor and systemic mosaic and malformations in tomato and tobacco plants. Symptomatic herbaceous hosts tested positive for TMV antibodies in ELISA. To the best of our knowledge, this is the first report of TMV on cabbage in Iran. © 2014, Edizioni ETS. All rights reserved.


Sokhansanj Y.,Islamic Azad University at Tehran | Rakhshandehroo F.,Islamic Azad University at Tehran | Pourrahim R.,Plant Pests and Diseases Research Institute
Plant Disease | Year: 2012

Chili pepper (Capsicum frutescens) represents an important crop in Iran and is under cultivation in different regions in Northern Iran. In spring 2012, commercially grown tabasco (Capsicum frutescens) peppers in Varamin, Shahriar, and Karaj districts of Tehran province developed an undescribed disease. Symptoms observed were mosaic, leaf malformations, and stunting. Fruit symptoms included chlorosis and distortion. To verify the identity of the disease, six fields were surveyed and 72 symptomatic leaves were collected and screened by double antibody sandwich (DAS)-ELISA using specific antibodies to Tobacco ringspot virus (TRSV), Tomato ringspot virus (ToRSV), Pepper mild mottle virus (PMMV), Tomato mosaic virus (ToMV), Tobacco mosaic virus (TMV), and Arabis mosaic virus (ArMV). ToRSV was found in 23% of the samples collected. None of the samples had a positive reaction to other tested viruses. The ToRSV-positive peppers were used for mechanical transmission to Chenopodium quinoa, local lesion host, and after two cycles of single local lesion isolation, they were transferred to Cucumis sativus, Solanum esculentum, and Capsicum fructescens. Inoculations resulted in systemic mosaic and chlorotic local lesion on C. sativus; leaf distortion and mosaic on S. esculentum; and mosaic, mottle, and stunting on C. fructescens. All inoculated plants were positive for ToRSV with DAS-ELISA. To further verify ToRSV infection, reverse transcription (RT)-PCR was conducted. Two primers were designed on the basis of the highly conserved sequences of the putative viral polymerase gene available in the GenBank. RT-PCR of total RNA extract from infected peppers and inoculated plants with the designed primers RdR-R (5?-CGCCTGGTAATTGAGTAGCCC-3') and RdR-F (5?-GAAGAGCTAGAGCCTCAACCAGG-3'), consistently amplified the 411-bp product, while no amplification products were obtained from noninfected control (healthy plants). The fragment from tabasco pepper was cloned into pTZ57R/T (Ins T/A clone PCR Cloning kit, Fermentas, St. Leon-Rot, Germany) and sequenced in both directions of three clones. The resulting nucleotide sequence (GenBank Accession No. JQ972695) had the highest identity (94%) with the polymerase gene of a ToRSV isolate from blueberry cv. Patriot (Accession No. GQ141528) and had lower identity (91%) with that of a ToRSV isolate from blueberry cv. Bluecrop (Accession No. GQ141525). Tomato ringspot virus (ToRSV) is reported to infect Capsicum spp. in the United States (1,2). Our results confirm the natural infection of pepper plants in Tehran by ToRSV. To our knowledge, this is the first report of ToRSV infection of pepper in Iran. The finding of this disease in Tehran confirms further spread of the virus within northern regions of Iran and prompts the need for research to develop more effective management options to reduce the impact of ToRSV on pepper crops. Beside, primers designed on the basis of putative viral polymerase gene sequences may improve the detection of ToRSV isolates by RT-PCR in Iran. © The American Phytopathological Society.


Hashemi S.S.,Islamic Azad University at Tehran | Rakhshandehroo F.,Islamic Azad University at Tehran | Shahraeen N.,Plant Pests and Diseases Research Institute
Plant Disease | Year: 2014

The natural incidence of Tomato mosaic virus (ToMV) in common sow thistle (Sonchus oleraceus) from vegetable fields was assessed to determine the role of this weed species as a virus inoculum source. Twenty sow thistle plants with virus-like foliar symptoms including mosaic and malformations were collected from five vegetable fields in Tehran province, Iran, and analyzed by double antibody sandwich (DAS)-ELISA for the presence of ToMV, Tobacco mosaic virus (TMV), and Cucumber mosaic virus (CMV) using specific polyclonal antibodies (Agdia, Elkhart, IN). Six out of the 20 sow thistle plants tested by ELISA were infected with ToMV. This virus was detected in three of five vegetable fields surveyed, while CMV and TMV were not detected. Mosaic symptoms were associated with the ToMV infection, similar to those caused by TMV in common sow thistle in Iran (2). Viral infection was confirmed by RT-PCR using previously described specific primers to amplify a region in the coat protein gene of ToMV (3). The RT-PCR resulted in the amplification of an expected fragment of ~480 bp from ToMV-infected but not from healthy plants. The nucleotide sequence of the amplified DNA fragment was purified (GeneJET Gel Extraction Kit, Fermentas, Germany), directly sequenced, and deposited in GenBank as Accession No. KF527464. BLAST analysis showed 95 to 97% and 98 to 100% identity at the nucleotide and amino acid levels, respectively, with comparable sequences of other ToMV isolates (GenBank AF062519, FN985165, GQ280794, and JX857634). Mechanical inoculation of sow thistle plants with sap of symptomatic sow thistles reproduced symptoms of field-infected sow thistles. The presence of ToMV in the inoculated plants was confirmed by ELISA and RT-PCR. This suggested that ToMV could be the causal agent of the disease on sow thistle. In our earlier studies, the distribution and genetic diversity of ToMV isolates infecting vegetable crops and weed plants were studied (1); however, to our knowledge, this is the first report of ToMV infecting common sow thistle in Iran. © 2014 The American Phytopathological Society.


Karami-Osboo R.,Plant Pests and Diseases Research Institute | Mirabolfathy M.,Plant Pests and Diseases Research Institute | Aliakbari F.,Islamic Azad University at Tehran
Journal of Agricultural Science and Technology | Year: 2010

Deoxynivalenol contamination was determined in corn produced in Golestan and Ardabil (Moqan) Provinces, Iran, in 2004-2005. Samples were collected from different stages of production, including before harvest, at harvest, post harvest as well as after drying. Ground sub samples were extracted with water; each extracted sample was cleaned up through an immunoaffinity column. Deoxynivalenol was estimated through reversed-phase High Performance Liquid Chromatography (HPLC). The linearity of standard curve for 50 -10,000 ng ml-1 of standard solutions was proved (R2= 0.9999). Detection limit was 10 ng g-1. Recovery of the method for 1,000 and 500 ng g-1 spiked samples was 73.5% and 93.5% (n= 5). Deoxynivalenol contamination was found in 76.7% of samples in the range of 54.4-518.4 ng g-1. The mean of contamination was 116.25 ng g-1. This is the first report of natural DON contamination of corn from Iran.


Damadi S.M.,Islamic Azad University at Maragheh | Pei M.H.,Rothamsted Research | Smith J.A.,University of Florida | Abbasi M.,Plant Pests and Diseases Research Institute
Forest Pathology | Year: 2011

A rust fungus was found causing stem cankers on 1- to 5-year-old stems of Salix elbursensis in the north west of Iran. The rust also forms uredinia on leaves and flowers of the host willow. Light and scanning electron microscopy revealed that the new rust is morphologically distinct from several Melampsora species occurring on the willows taxonomically close to S. elbursensis, but indistinguishable from Melampsora larici-epitea. Examination of the internal transcribed spacer (ITS) region of the ribosomal DNA suggested that the rust fungus is phylogenetically close to Melampsora allii-populina and Melampsora pruinosae on Populus spp. Based on both the morphological characteristics and the ITS sequence data, the rust is described as a new species -Melampsora iranica sp. nov. © 2010 Blackwell Verlag GmbH.


Jamalizadeh M.,University of Tehran | Etebarian H.R.,University of Tehran | Aminian H.,University of Tehran | Alizadeh A.,Plant Pests and Diseases Research Institute
EPPO Bulletin | Year: 2011

Several possible biocontrol mechanisms have been suggested as being effective against post-harvest fruit spoilage. These include competition (for nutrients and space), antibiosis, parasitism, induction of resistance in the host tissue and production of volatile metabolites. Information on the mechanisms of action for most of the antagonists is still incomplete because of the lack of information on the complex interactions between the host, the pathogen, the antagonist and the other microorganisms present. However, a good understanding of the mechanism of action is essential before developing appropriate formulations and methods of application in order to obtain official approval. In this review information is provided about several mechanisms of biocontrol agents that could provide future biocontrol agents. © 2011 The Authors. Journal compilation © 2011 OEPP/EPPO.


Iranipour S.,University of Tabriz | Pakdel A.K.,University of Tehran | Radjabi G.,Plant Pests and Diseases Research Institute | Michaud J.P.,Kansas State University
Bulletin of Entomological Research | Year: 2011

Life table studies of sunn pest were carried out in Varamin, Iran, from 1998-2001 in order to determine stage-specific mortalities and the impact of specific natural enemies on population dynamics. Populations were sampled 2-3 times weekly in agricultural fields during the growing season and monthly during the period of dormancy at resting sites in nearby mountains some 30 km away from cereal fields. Adults spend a period of 9-10 months in diapause and suffered overcompensatory, density-dependent mortality during this period. Variation in adult overwintering survival was inferred to be largely a function of the physiological condition of bugs that is reduced in a density-dependent manner by intraspecific competition for food among newly molted adults prior to migration to resting sites. Adult mortality emerged as the primary factor in key factor analysis, contributing 73% of the total variance in mortality. Other important factors were egg parasitism by Trissolcus vassilievi Mayr and adult parasitism by several species of Tachinidae. Although T. vassilievi made only a minor contribution to overall variance in total mortality, it had a significant effect on the number of newly molted adults, the life stage that is most damaging to cereal crops. The equilibrium level of the pest population in wheat fields was inferred to be ca. 72.6 adults m-2, a number that substantially exceeds the economic threshold that ranges from 3-5 adults m -2. Copyright © Cambridge University Press 2010.


Iranipour S.,University of Tabriz | Pakdel A.K.,University of Tehran | Radjabi G.,Plant Pests and Diseases Research Institute
Journal of Insect Science | Year: 2010

The Sunn-pest, Eurygaster integriceps Puton (Heteroptera: Scutelleridae), is the most important insect pest of wheat and barley in Iran. A demographic study was carried out in order to determine the effect of temperature on life history parameters of the pest. Life tables were constructed at four constant temperatures: 22, 25, 27, and 30 ± 1° C using Mahdavi wheat kernels as food. Finite and intrinsic rates of population increase, gross and net reproductive rates, intrinsic rates of birth and death, generation time, doubling time, and lifetime female fecundity all varied significantly among temperatures. The intrinsic rate of natural increase, rm, increased linearly with temperature and was estimated to be 0.0126, 0.0381, 0.0541, and 0.0789 females/female/day, respectively, at the above-mentioned temperatures. Generation time ranged from 121 days at 22° C to 40 days at 30° C. Net replacement rate was significantly lower at 22° C than at other temperatures (4.6 vs. 22.2 to 25.8 females/female/generation). Lifetime female fecundity ranged from 123.1 at 22° C to 209.4 at 30° C. The thermal threshold for post-diapause pre-reproductive development was estimated to be 20° C, and 66.8 degree-days were required for its completion.


Gharalari A.H.,University of Manitoba | Gharalari A.H.,Plant Pests and Diseases Research Institute | Smith M.A.H.,Cereal Research Center | Fox S.L.,Cereal Research Center | Lamb R.J.,Cereal Research Center
Canadian Entomologist | Year: 2011

Female wheat midges, Sitodiplosis mosellana (Ghin) (Diptera: Cecidomyiidae), were provided with wheat spikes, Triticum aestivum L. (Poaceae), for oviposition while being exposed to air that had passed over wheat spikes of contrasting genotype or growth stage. Spikes of postanthesis 'Roblin' and preanthesis 'Key 10' are known to deter oviposition. Volatiles emitted by these spikes suppressed oviposition on preanthesis 'Roblin', which is preferred for oviposition. Volatiles emitted by spikes of preanthesis 'Roblin' did not increase oviposition on preanthesis 'Key 10'. Reduced oviposition on a resistant genotype and on a deterrent growth stage of wheat is consistent with production of deterrent volatiles rather than a lack of stimulatory volatiles. © 2011 Entomological Society of Canada.


Nasr Isfahani M.,Plant Pests and Diseases Research Institute | Alizadeh G.,Plant Pests and Diseases Research Institute | Ramazani S.,Plant Pests and Diseases Research Institute
Archives of Phytopathology and Plant Protection | Year: 2014

Genetical diversity of Fusaria dry rot species of potato, Fusarium sulphureum, Fusarium solani, and Fusarium oxysporum, was assessed on even size tubers of potato genotypes. Ten tubers of each sample were inoculated with each species individually. They were incubated in plastic boxes, the two sub-samples of 10 being separated by a plastic divider, for eight weeks at 10 °C. The atmosphere of the incubation chamber was kept at high humidity by blowing steam into the air stream surrounding the boxes. The amount of dry rot was assessed by cutting each tuber transversely into two through the wound, and estimating the fraction of the exposed tissue colonised by the fungus, using the scoring scale 0-24. The greater aggressiveness was of F. sulphureum, with a mean overall score 15.27 higher than that of F. solani, with a highly significant effect, followed by F. oxysporum, and the differences between genotypes in the reaction of the three pathogens are apparent. In fact, the colonisation score here measures the size of the rot in the tuber, which assesses the within-tuber spread rather than the number of wounds infected. The rank order of infection to the two main species differs markedly, and the correlation is not significant, indicating that infection to each species is independent. The estimates of the infections of some of the genotypes showed good ranking for F. sulphureum and F. solani as far as the colonisation scores of the genotypes in common are concerned. © 2013 © 2013 Taylor & Francis.

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