Barriopsis iraniana and Phaeobotryon cupressi: two new species of the Botryosphaeriaceae from trees in Iran

Species in the Botryosphaeriaceae are well known as pathogens and saprobes of woody hosts, but little is known about the species that occur in Iran. In a recent survey of this family in Iran two fungi with diplodia-like anamorphs were isolated from various tree hosts. These two fungi were fully characterised in terms of morphology of the anamorphs in culture, and sequences of the ITS1/ITS2 regions of the ribosomal DNA operon and partial sequences of the translation elongation factor 1-α. Phylogenetic analyses placed them within a clade consisting of Barriopsis and Phaeobotryon species, but they were clearly distinct from known species in these genera. Therefore, they are described here as two new species, namely Barriopsis iraniana on Citrus, Mangifera and Olea, and Phaeobotryon cupressi on Cupressus sempervirens

Evaluation of common bean lines for their reaction to the common bacterial blight pathogen

Common bacterial blight (CBB) caused by Xanthomonas axonopodis pv. phaseoli (Xap) is an economically important disease of common beans (Phaseolus vulgaris L.). Since there is no satisfactory chemical control for CBB, the use of resistant cultivars is an important management strategy. In the present study, twenty nine lines and one cultivar of common bean were evaluated for their reaction to Xap under greenhouse and field conditions. The experiments were conducted in randomized complete blocks with three replications. Reaction to Xap was assessed as diseased leaf area (DLA) and the number of spots on the leaves. Data analysis indicated that cultivar Khomein and the Ks21479 and Ks31169 lines were the most susceptible, while Ks51103, BF13607 and BF13608 lines were the most resistant. The data obtained from greenhouse and field experiments were in agreement. None of the evaluated lines and/or cultivars was immune for CBB; however, the three resistant lines were identified for use in cultivation or as sources of resistance to CBB in plant breeding programs

Identification of viruses infecting cucurbits and determination of genetic diversity of cucumber mosaic virus in Lorestan province, Iran

Various viral pathogens infect Cucurbitaceae and cause economic losses. Th e aim of the present study was to detect plant viral pathogens including Cucumber mosaic virus (CMV), Cucumber green mottle mosaic virus (CGMMV), Zucchini yellow mosaic virus (ZYMV), Cucurbit yellow stunting disorder virus (CYSDV) and Cucurbit chlorotic yellows virus (CCYV) in Lorestan province, in western Iran, and also to determine CMV genetic diversity in Iranian populations. A total of 569 symptomatic leaf samples were collected in 2013 and 2014 from cucurbits growing regions in Lorestan province. Th e collected samples were assessed for viral diseases by ELISA. Th e results showed virus incidences in most regions. Th en, the infection of 40 samples to CMV was confi rmed by RT-PCR. Moreover, to distinguish between the two groups (I and II) of CMV, PCR products were digested by two restriction enzymes XhoI and EcoRI. Results of the digestion showed that the isolates of Lorestan belonged to group I. Th e CMV-coat protein gene of eight isolates from diff erent regions and hosts was sequenced and phylogenetic analysis was performed. Subsequent analyses showed even more genetic variation among Lorestan isolates. Th e phylogenetic tree revealed that Lorestan province isolates belonged to two IA and IB subgroups and could be classifi ed together with East Azerbaijan province isolates. Th e results of the present study indicate a wide distribution of CMV, ZYMV, CGMMV, CYSDV and CCYV viruses in cucurbits fi elds of Lorestan province and for the fi rst time subgroup IB of CMV was reported on melon from Iran

Prevalence and phylogenetic analysis of Fig mosaic virus and Fig badnavirus-1 in Iran

Fig mosaic virus (FMV) and Fig badnavirus-1 (FBV-1) are two of the most important fig infecting viruses. The incidence and distribution of FBV-1 and FMV were determined by testing in PCR 138 asymptomatic and symptomatic samples. These samples were collected from 60 fig gardens and agricultural fields in three provinces of Iran. The fig infecting viruses FBV-1 and FMV, respectively, were detected in 92 (66.6%) and 34 (24.6%) samples collected from all the surveyed fields. Overall, 24 out of 138 (17.3%) samples showed mixed infections. The sequence analysis of a genomic fragment of 922 nt, comprising the entire ORF-2 and part of the 5’ termini of the ORF-3 of 10 selected FBV-1 Iranian isolates from different provinces, and of the type member from GenBank (Acc. No: JF411989), showed a variation ranging from 1 to 3% at nucleotide level and 1% at the amino acid level. The phylogenetic analysis grouped the FBV-1 isolates into two groups, with the Iranian isolates clustered in two distinct subgroups of group I, according to their geographical origin. In our research, the prevalence and sequence analysis of FBV-1 as the only identified DNA virus infecting fig trees, was studied for the first time in Iran

Genetic diversity among Xanthomonas citri subsp. citri strains in Iran

Citrus bacterial canker (CBC) is one of the most important diseases of citrus. It is caused by Xanthomonas citri subsp. citri (Xcc). To investigate the variability of Xcc, a collection of twenty-five strains were isolated from the Fars, Hormozgan, Kerman and Sistan-va-Baluchestan provinces of Iran. The twenty-five strains were assessed phenotypically and genetically. These strains had similar biochemical properties. Based on host range determination, the strains were divided into two groups; the first group was pathogenic on Mexican lime (Citrus aurantifolia), citrumelo (Poncirus trifoliata x C. paradisi), citrange (C. sinensis x P. trifoliata) and sour orange (C. aurantium) varieties. The second group was pathogenic on Mexican lime only. Profile of cellular soluble proteins analyzed by sodium dodecyl sulphate-polyacryamid gel electrophoresis (SDS-PAGE) did not reveal any considerable differences among strains. Genetic diversity analyses were performed using two marker systems; repetitive polymerase chain reaction (rep-PCR) and random amplified polymorphic DNA (RAPD). The results of this research showed that two primers, ERIC 1R and 232, with the highest marker index, resulted in the most genetic variability among strains. Cluster analysis by band patterns showed that strains from the Sistan-va-Baluchestan province were a different group, so it was concluded that geographical origin of strains from the Sistan-va-Baluchestan province is different than the geographical origin of strains isolated from other provinces

Generation and expression in plants of a single-chain variable fragment antibody against the immunodominant membrane protein of Candidatus Phytoplasma aurantifolia

Witches' broom of lime is a disease caused by Candidatus Phytoplasma aurantifolia, which represents the most significant global threat to the production of lime trees (Citrus aurantifolia). Conventional disease management strategies have shown little success, and new approaches based on genetic engineering need to be considered. The expression of recombinant antibodies and fragments thereof in plant cells is a powerful approach that can be used to suppress plant pathogens. We have developed a single-chain variable fragment antibody (scFvIMP6) against the immunodominant membrane protein (IMP) of witches' broom phytoplasma and expressed it in different plant cell compartments. We isolated scFvIMP6 from a naive scFv phage display library and expressed it in bacteria to demonstrate its binding activity against both recombinant IMP and intact phytoplasma cells. The expression of scFvIMP6 in plants was evaluated by transferring the scFvIMP6 cDNA to plant expression vectors featuring constitutive or phloem specific promoters in cassettes with or without secretion signals, therefore causing the protein to accumulate either in the cytosol or apoplast. All constructs were transiently expressed in Nicotiana benthamiana by agroinfiltration, and antibodies of the anticipated size were detected by immunoblotting. Plant-derived scFvIMP6 was purified by affinity chromatography, and specific binding to recombinant IMP was demonstrated by enzyme-linked immunosorbent assay. Our results indicate that scFvIMP6 binds with high activity and can be used for the detection of Ca. Phytoplasma aurantifolia and is also a suitable candidate for stable expression in lime trees to suppress witches' broom of lime

Occurrence, distribution, and molecular characterization of apple stem pitting virus in Iran

Apple Stem Pitting Virus (ASPV) is one of the most common viruses of apple and pear trees. During 2012 to 2013, a total of 1053 symptomatic and asymptomatic leaf samples were collected from orchards in nine provinces of Iran. ASPV infection was detected by DAS-ELISA and PCR in 54 samples (5.12%) from seven provinces. Based on the geographical origin, 22 representative isolates were selected for phylogenetic analysis. Twenty-two amplicons with a size of about 370 base pair (bp) comprising partial sequence of the Coat Protein (CP) coding regions of the viral genome were sequenced. Sequence data analysis, showed that the identities of 3\u2019-terminal region of CP gene at both nucleotide and amino acid levels among the Iranian isolates were 95\u2013100% and these isolates were closer to the Asian ASPV isolates than to the other isolates. Constructed phylogenetic tree by Neighbor-joining on the basis of the 3\u2019-terminal region of CP gene sequences showed that the Iranian isolates were categorized into two major groups. Furthermore, phylogenetic and population genetic analysis were carried out on the basis of 3\u2019-terminal region of CP gene which revealed that ASPV isolates were not geographically resolved. Also, all values in the GABranch analysis showed a ratio of substitution rates at Non-synonymous and Synonymous sites (dN/dS) below one, suggesting strong negative selection forces during C-terminal region of the ASPV CP gene history. To the best of our knowledge, this is the first report of distribution and partial genome sequence analysis of the ASPV in Iran. \ua9 2017, Tarbiat Modares University. All rights reserved

Incidence and genetic diversity of apple chlorotic leaf spot virus in Iran

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\u2032 end of the movement protein (MP), the coat protein (CP) gene, and 3\u2032-UTR sequence, were sequenced. Sequence analysis, using data of 45 isolates from 12 different countries, including the 19 Iranian isolates, showed that CP gene among the Iranian isolates were 80\u201399% identical at both nucleotide and amino acid levels, and these isolates were placed in the B6 (AB326224) and P-205 (D14996) ACLSV groups. This is the first genetic analysis of ACLSV in Iran