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Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas), is an important and threatening disease for the citru s industry in southeast Iran. In the present study, seasonal dynamic monitoring of CLas was conducted by absolute real-time PCR. Plant materials were obtained across 7 and 6 months from December 2014 to October 2015 from three parts of the canopy of two naturally infected citrus species, Mexican lime (Citrus aurantifolia) and sweet orange (C. sinensis) located in two distinct geographical regions, Sistan-o-Baluchestan and Kerman provinces, respectively. Results showed significant variation (α= 0.001) in the bacterial titers in both infected hosts. These notable changes have also been observed in all tree’s canopy
The Severe strain of Beet Curly Top Virus (BCTV-Svr) and Beet Curly Top Iran Virus (BCTIV) are considered as the main causal agents of sugar beet curly top disease in Iran and mixed infections of BCTV-Svr and BCTIV usually occur in nature. As the use of resistant cultivars is the safer and stable tool for management of the disease, the objective of current work was to identify sugar beet genotypes resistant to both agents. To this end, the reaction of thirty-eight sugar beet genotypes to infection by each of BCTV-Svr and BCTIV was separately evaluated using their infectious clones under the greenhouse condition. Incubation period, recovery, and disease severity index were considered for selection of resistant genotypes. As a result, ten and
Curly top is one of the most important viral diseases of sugar beet. Use of resistance sources is a promising strategy for control of this disease. In the present study, the efficiency of four gene silencing constructs (OUT-hp، IN-hp، sense and antisense) against two major causes of curly top disease in Iran, beet curly top virus-Svr (BCTV) and beet curly top Iran virus (BCTIV), were evaluated in transgenic plants. Selection of transgenic plant seeds was carried out on selective medium 1/2MS containing glufosinate-ammonium (Basta) and the results showed that the pBCTV-IN-hp construct resulted in the highest germinated seeds. Selected plants were transferred to greenhouse and evaluated for resistance to basta and detection of silencing con
Brenneria species are bacterial plant pathogens mainly affecting woody plants. Association of all members with devastating disorders (e. g. acute oak decline in Iran and UK) are due to adaptation and pathogenic behavior in response to host and environmental factors. Some species, including B. goodwinii, B. salicis and B. nigrifluens, also show endophytic residence. Here we show that all species including novel Brenneria sp. are closely related. Gene-based and genome/pangenome-based phylogeny divide the genus into two distinct lineages, Brenneria clade A and B. The two clades were functionally distinct and were consistent with their common and special potential activities as determined via annotation of functional domains. Pangenome analysis
Among several studied strains, Streptomyces rochei IT20 and S. vinaceusdrappus SS14 showed a high level of inhibitory effect against Phytophthora capsici, the causal agent of pepper blight. The effect of two mentioned superior antagonists, as single or combination treatments, on suppression of stem and fruit blight diseases and reproductive growth promotion was investigated in pepper. To explore the induced plant defense reactions, ROS generation and transcriptional changes of selected genes in leaf and fruit tissues of the plant were evaluated. The plants exposed to the combination of two species responded differently in terms of H2O2 accumulation and expression ratio of GST gene compared to single treatments upon pathogen inoculation. Bes
Stem rust, caused by Puccinia graminis f. sp. tritici (Pgt), is one of the most important diseases of wheat with devastating epidemics in Iran and the world. In this study, we evaluated some Iranian wheat landraces in a greenhouse at the seedling stage against a new pathotype related to Ug99 of Pgt, which was collected from Iran and designated as TTSSK. Marker analysis was done on resistant landraces. Molecular markers for detecting some Sr genes were used. The results showed that Sr22, Sr35 and SrWeb provided resistance against TTSSK in the resistant landraces. In addition, some of the susceptible landraces that were resistant at adult stage were used for Sr2 analysis. The results showed that some of these landraces were carrying other adu
Potato is the most important non-grain food crop in the world. Viruses, particularly potato virus Y (PVY) and potato virus A (PVA), are among the major agricultural pathogens causing severe reduction in potato yield and quality worldwide. Virus infection induces host factors to interfere with its infection cycle. Evaluation of these factors facilitates the development of intrinsic resistance to plant viruses. In this study, a small G-protein as one of the critical signaling factors was evaluated in plant response to PVY and PVA to enhance resistance. For this purpose, the gene expression dataset of G-proteins in potato plant under five biotic (viruses, bacteria, fungi, nematodes, and insects) and four abiotic (cold, heat, salin
Background: High antagonistic ability of different Trichoderma species against a diverse range of plant pathogenic fungi has led them to be used as a biological fungicide in agriculture. They can also promote plant growth, fertility, resistance to stress, and absorption of nutrients. They are also opportunistic and symbiotic pathogens, which can lead to the activation of plant defense mechanisms. Objectives: The aim of this present study was to investigate possible enhancement of lytic enzymes production and biocontrol activity of T. virens against Rhizoctonia solani through gamma radiation and to find the relationship between changes in lytic enzyme production and antagonistic activity of T. virens. Material and Methods: Dual culture condi
Iranian Journal of Plant Protection Science (IJPPS).
Mixed infections of plants with viruses is a common phenomenon occurring in nature. In the present study, interactions between Beet curly top virus (BCTV-Svr), Beet curly top Iran virus (BCTIV) and Cucumber mosaic virus (CMV) were investigated in resistant cultivar (BST853) of sugar beet (Beta vulgaris) to curly top disease at 20?C and 26 ?C; pepper (California Wander cultivar) and bean (Akhtar and Goli cultivars) at 26 ?C. Experiments were performed in a completely randomized design. Plants were inoculated with infectious clones of BCTV-Svr and BCTIV and also mechanically with the sap of the Fars isolate of CMV infected Cucumis sp. leaves. The intensity of the bands of PCR products was evaluated by Totallab software. The viruses did not in
Apple chlorotic leaf spot virus (ACLSV) is one of the most common viruses infecting apple and pear trees, and Iran is among the top ten apple-producing countries in the world. In the present study, incidence and genetic diversity of ACLSV were investigated in the main apple-growing regions of Iran. To achieve this purpose, a total of 1053 leaf samples were collected from orchards located in nine Iranian provinces. ACLSV infection was detected by DAS-ELISA in 48 samples (4.55%) from seven provinces and was confirmed by RT-PCR. Based on the geographical origin, 19 representative isolates were selected for phylogenetic analysis. Nineteen amplicons, with a size of 677 base pairs (bp), containing the 3′ end of the movement protein
Diaphorina citri is a vector of ‘Candidatus Liberibacter asiaticus,’ (CLas), associated with Huanglongbing, (HLB, or citrus greening) disease in citrus. D. citri exhibits three different color morph variants, blue, gray and yellow. Blue morphs have a greater capacity for long-distance flight as compared to non-blue morphs, but little else is known about how color morphology influences vector characteristics. In this study, we show that the color morphology of the insect is derived from pigmented cells of the fat body. Blue morphs acquire a lower level of CLas in their bodies from infected trees as compared to their gray and yellow conspecifics, referred to in this paper collectively as non-blue morphs. Accordingly, CLas titer in citrus