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Fungal diseases are the major factors of sugar beet yield losses worldwide. Expression of pathogenesis-related proteins such as chitinases is considered as one of the plant defense responses against pathogens. Chitinases are cell wall degrading enzymes which have been shown to have high antifungal activity against a wide range of phytopathogenic fungi. In this study, two diploid sugar beet genotypes, SBSI-02 and SBSI-04, were used for transformation through Agrobacterium tumefaciens strain LBA4404 harboring the pBI-BCH plasmid containing the chi gene under the control of the CaMV35S promoter and the nptII selectable marker gene. Leaf blade with attached shoot bases were used as explant substratum for transformation. Green shoots were successfully screened using different concentration of kanamycin. PCR screening with chi-specific primer showed the presence of the transgene in more than 50% of regenerated kanamycin-resistant plants. Dot blot analysis confirmed the integration of at least one copy of the chi gene into the genome of putative transgenic plants. Western blot analysis revealed chitinase protein accumulation in transgenic plants. The content of chitinase protein varied among the five T0 transgenic plants. Bioassay analysis using detached leaves and at the whole plant level revealed increased resistance of T0 transgenic sugar beet lines against the fungal pathogen Alternaria alternata compared to non-transformed control plants.

Prunus necrotic ringspot virus (PNRSV)، Apple mosaic virus (ApMV) and Arabis mosaic virus (ArMV) are important rose viruses in the world. The aims of this study were to detect the viruses and evaluate their distribution in damask rose floricultures of the Isfahan، Kerman and Markazi Provinces. To do this، total 749 leaf samples were collected randomly from floricultures of the mentioned provinces in 2012-13. Presence of the viruses in the samples was checked by DAS-ELISA using specific antibodies against each of the viruses. The result of ELISA test on collected samples in 2012 showed that 4. 41%، 2. 20% and 6. 3% of the samples were infected with ArMV، ApMV and PNRSV، respectively. These percentages for samples collected in 2013، were 2. 31%، 5. 32% and 4. 16%. Because of wider distribution of PNRSV in comparison to ArMV and ApMV، coat protein gene in four isolates of PNRSV was cloned and sequenced. Phylogenetic tree was drawn and recombination analyses were performed. Based on the phylogenetic tree، Iranian isolates were placed in PV96 phylogroup. This is the first report of genetic diversity of PNRSV in Iran and also the first incidence report of ArMV، ApMV and PNRSV in Isfahan and Markazi provinces.

Root rot disease is one of the most important sugar beet disease in Iran that infected by Pythium aphanidermatum Fitzp. For studying genetic diversity of this pathogen, 10-20 samples were collected from sugar beet fields in eight provinces of Iran. After purification, isolates were identified based on morphological characteristics of sexual and asexual organs and 19 isolates were selected in order to molecular diversity studies. ISSR analysis of all isolates was performed using eight primers. Results of phylogenetic tree of primers based on UPGMA method and Jacards similarity coefficient, were categorized isolates into five groups (64% similarity). The results of analysis of growth rate in two temperatures at 26±2Cº and 29±2Cº, by MSTATC and MVSP, was categorized isolates in to two groups with low growth and high growth rate. Analysis of morphological and molecular variation were indicated that isolates of this eight geographical regions have genetic relationship but there isnt necessary relationship between growth rate of isolate and their geographical distribution.

Potato virus Y (PVY), Potato virus X (PVX), Potato virus S (PVS) and Potato leaf roll virus(PLRV), are the most important viruses of potato and can cause serious diseases andsignificantly reduce the yield and quality of potato crops. The incidence of these viruses isreported from almost all main potato growing regions in Iran. Therefore, application of a sensitive, rapid and inexpensive procedure for simultaneous detection of potato viruses is very important for management of their control. In the present research, a sensitive and reliable multiplex RT-PCR technique for the detection of PVY, PVX, PVS, PLRV and 18S rRNA as internal control was employed and compared with ELISA, the method used routinely to assay potatoes for virus infections. Total RNA was extracted from virus infected potato leaves. Then cDNA for above viruses and 18S rRNA was individually synthesized using their specific reverse primers and single RT-PCR for each virus and 18S rRNA. Subsequently, multiplex RT-PCR was carried out with five primer pairs in a single reaction. As a result, five different fragments (145-342 bp) specific to the viruses and the internal control were simultaneously amplified and were identified on the basis of their molecular sizes. The sensitivity of our optimized system also was compared with that of commercial DAS-ELISA for detection of PVY, PVS and PLRV. The results showed that the sensitivity of multiplex RT-PCR was 100-fold greater for detection of PVY, PVS and PLRV and the duplex RT-PCR was 1000-fold greater for detection of PVY than that of commercial DASELISA.

Septoria leaf blotch is one of the most important wheat diseases worldwide includingIran. To study the genetic diversity of Iranian isolates of Septoria tritici, the infected samples were collected from Khuzestan, Golestan, Ardebil and Kermanshah provinces. Twenty six out of 88 recovered isolates were selected according to their geographical origins for studying virulence and their genetic diversity using RAPD analysis. Analysis of virulence of disease severity data was statistically significant at 99% confidence level (p<0.01). Comparison ofthe means of disease severity, using Duncan’s multiple range test, divided the isolates into five groups. In genetic diversity studies, Six out of 15 random primers were polymorphic and reproducible. Cluster analysis of DNA fingerprint data using UPGMA method and Jaccard's coefficient, divided the isolates into 8 groups at 35% similarity level showing a high genetic diversity among Iranian populations of S. tritici. According to number of clusters in which the isolates of each region were placed, the highest genetic diversity belonged to Ardebil. This is the first report on the study of genetic diversity of Iranian populations of S. tritici.

Aims. Fusarium species are the most important group of fungi that produced a variety of mycotoxins which can contaminate food. The objective of the present study was presentation and identification of one isolate from Fusarium species belong to section of sporotrichiella, that recently isolated from stored wheat of Tehran province. Methods. This species isolated and purified by freeze blotter and single-spore method, respectively. Isolates cultured onto CLA, SNA, PDA and PSA. All microscopic and macroscopic characters studied. The DNA of this isolate amplified by PCR with F. sporotrichioides and F. langsethiae specific primers. Internal transcribed spacer (ITS) regions of isolate amplified, purified and sequenced using universal primers ITS4 & ITS5 and the fraction of TEF-1α gene also using external and nested primers. Results. On the basis of morphology and ribosomal internal, transcribed spacer (ITS) classified as F. langsethiae but on the basis of partial translation TEF-1α gene grouped with F. sporotrichioides. Conclusion. To our knowledge, this is the first report in Iran and Asia. Therefore, a large-scale monitoring of these fungi and T-2 toxin on wheat in Iran is necessary.