EVALUATION OF THE OBSERVANCE OF RADIATION PROTECTION PRINCIPLES IN KERMANSHAH PROVINCE (WEST OF IRAN) 2020: CROSS-SECTIONAL STUDY.

In this descriptive cross-sectional study by census method, the performance of 116 radiographers in the target centers was evaluated in relation to the observance of radiation protection principles with respect to patients, patient companion and radiographers. The data collection tool was a checklist containing 34 principles of radiation protection that were used after confirmation of its continuity and justifiability. The results showed that only in (39.2%) 45 radiographers the observance rate of the principles of radiation protection was acceptable. The highest and lowest levels in which radiographers observed protective principles were observance of protective principles with respect to themselves (60.8%) and protective principles respect of the patient companion (6.3%), respectively. According to the findings, radiation protection principles are not systematically designed, implemented, controlled and monitored by radiographers, and less than half of the radiographers observe the protection principles at the optimal level.

First report of cucumber mosaic virus subgroups i and ii on soybean, pea, and eggplant in iran.

UNLABELLED: Cucumber mosaic virus (CMV) has the widest host range (> 1000 plant species) of any known plant virus, a large number of vector species, and a wide geographical distribution. A survey was conducted to determine the incidence of CMV of subgroups I and II on selected host crops in northern Iran. A total of 935 leaf samples from 10 host crops (tomato, pea, tobacco, soybean, watermelon, broad bean, squash, cucumber, eggplant, and lettuce) showing virus disease-like symptoms were collected in 12 cities of Golestan and Mazandaran provinces (northern Iran) during 2009 and 2010. Among the field samples tested by double-antibody sandwich ELISA (DAS-ELISA), 275 samples were found to be infected by CMV. These were subsequently evaluated by compound ELISA with monoclonal antibodies. We found that 198 samples were infected by subgroup I, 98 samples by subgroup II and 45 samples by both virus subgroups. Twenty-four samples showed no reaction in compound ELISA. In presented paper, CMV subgroups I and II (CMV-I and CMV-II) have been reported for the first time on soybean, pea and eggplant in Iran, with subgroup I being dominant in the north of the country. KEYWORDS: CMV; subgroups I and II; compound ELISA; monoclonal antibody.

Virus diseases in the tobacco fields of Guilan and Western Azerbaijan provinces of Iran.

Tobacco (Nicotiana tabacum L.) is one of the important industrial plants in Iran. Viruses as an important group of plant pathogens cause many losses on the quality and quantity of tobacco crop. There was few information on the types of plant viruses infecting the tobacco fields of Guilan and almost no information for Western Azerbaijan province. During 2005-2007, leaf samples were taken from symptomatic plants in the growing areas of these two provinces. The observed symptoms on plants in the fields varied from mild mosaics to severe necrosis. The regions of sampling were including Rasht, Bazar-jomeh, Soumae-Sara, Talesh and Astara in Guilan and Ourmia, Sardasht and Ghara-Ziaeddin in Western Azerbaijan. The tobacco types and varieties from which the samples were taken included air-cured burley variety Burley 21 and to a lesser extent, oriental tobacco variety Basma Serres in W. Azerbaijan and flue-cured varieties Coker 347 and Virginia El in Guilan province. Samples were tested by DAS-ELISA method (Clark and Adams, 1977) using the polyclonal antibodies for a set of tobacco viruses. Some samples with positive reactions in DAS-ELISA were inoculated to indicator test plants such as Chenopodium amaranticolor, Datura metel, D. stramonium, Physalis floridana, Nicotiana rustica, N. glutinosa, and tobacco (varieties White burley and Samsun). The results of greenhouse experiments were consistent with serological tests. The following viruses which are listed in order of their overall abundance within the tested samples were detected: Tobacco streak virus (TSV), Tomato spotted wilt virus (TSWV), Tobacco etch virus (TEV), Tobacco ringspot virus (TRSV), Potato virus Y (PVY), Cucumber mosaic virus (CMV) and Tobacco mosaic virus (TMV). In all samples more than one virus infection was detected. The most severe mosaic type symptoms including the deformation and blistering on leaves were mainly seen in the infections by CMV and TMV. The most severe necrotic type symptoms including necrosis of midribs or veins and in some cases stem necrosis were generally associated with the infections by PVY and TSWV. Except TMV infection which was not detected in the Burley 21 variety in W. Azerbaijan, the above mentioned viruses were present in all sampling regions. The lack of TMV infection on Burley 21 is due to the presence of N gene, conferring resistance in this variety.

High incidence of tobacco streak virus in the tobacco fields of Iran.

Currently the northern provinces of Iran (Mazandaran, Golestan and Gilan) are the main tobacco growing regions in the country and this crop has an special importance in the national economy. Three tobacco types including flue-cured (mainly Coker 347 and some Virginia E1), burley (Burley 21) and oriental (Basma 178-2) are presently grown in these regions. Epidemics of viral diseases have occurred during the recent years in many tobacco fields in these areas. The quality of tobacco products which is much important, is adversely affected by plant pathogens specially viruses. In a survey on the viruses of tobacco, the fields in these regions were inspected and leaf samples from symptomatic plants were collected. Some plants had one or more of the symptoms such as dentate leaf margin, thicker leaf tissue and necrotic areas on the stem. The samples were tested for TSV infection by the DAS-ELISA method (Clark and Adams, 1977) using polyclonal antibody (AS-0615, DSMZ, Germany). TSV was detected in more than 79% of all tobacco samples from these three provinces. The TSV infection level among the tested samples was 86.8% in Gilan (Rasht, Bazar-Jomeh and Talesh), 82.3% in Mazandaran (Behshahr, Sari, Neka and Sourak) and 71.8% in Golestan (Gorgan, Aliabad and Minoodasht). No significant difference was seen among the infection levels for the mentioned commercial varieties and also some other tested varieties such as C176, K326 and MN944. It seems that there is no resistance sources against this virus within these varieties. Also the results of tests for TSV were similar in two consecutive years (2004 and 2005). It should be added that not all of the TSV infected plants showed the stated symptom types. Many of the TSV infected samples had mixed infections with one or more other viruses such as TSWV, CMV, PVY and TMV and there was almost no sample with a single TSV infection. This is the first report on the occurrence and distribution of TSV in the tobacco fields of Iran, too.

Evaluating the efficiency of a TPIA method for the detection of two tobacco viruses.

Field experiments are usually necessary for analyzing the efficiency of control methods, the resistance of varieties and many other virological studies. Such experiments generally include a large number of samples to be tested serologically. DAS-ELISA is a very accurate technique that has been widely used for identifying viral infections. For large numbers of plant samples, it takes a long time for the sample preparation, plate washing and other procedures. In this study, the efficiency of a simple and laborsaving TPIA (Tissue Print Immunoassay) method was evaluated for the identification of two important aphid-transmitted viruses (CMV and PVY) of tobacco fields in comparison with DAS-ELISA as the standard method. The leaf samples were collected from the fields of three commercial tobacco types (flue-cured, burley and oriental). Each sample was divided to two parts and each part was examined by one of the methods. DAS-ELISA was done based on the method described by Clark and Adams (1977). In TPIA, small parts of the leaf samples were rolled and then cut by a sterile sharp blade. The cut surface was gently printed on 1 cm2 blocks drawn on a nitrocellulose paper. Air dried paper was located first in 1% BSA for blocking the empty sites on paper, then in the buffer containing AP-conjugated polyclonal antibody for 3 h and finally in NBT-BCIP solution for color development. Between these stages, the paper was washed thoroughly (three times) by shaking in fresh washing buffer. The results of each sample were recorded and compared with those of DAS-ELISA. By considering DAS-ELISA as the reference method, the sensitivity of TPIA for the detection of PVY and CMV was 96.1% and 92.7%, respectively. The positive results by TPIA which were not detected positive by DAS-ELISA were regarded as false positive. These were 8 (out of 316 tested samples) for CMV and 6 (out of 204 samples) for PVY. Although the results of TPIA were not completely consistent with DAS-ELISA, it seems that this method can be used for some general studies. The most important advantages of this method were that it didn't need sample extraction and was done using only one antibody which was the conjugated antibody of each virus. This method gives more rapid results (within a day) in comparison with DAS-ELISA that needs more time.