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This investigation was conducted to compare the photosynthetic indices in ironwood trees infected by Viscum album L. and healthy trees located both in stand and out of stand in plain forest of Tamishan, Nour city. In each position, five healthy and five infected trees were selected and photosynthetic parameters, stomatal conductance, transpiration and internal CO₂ were examined. Results showed that the amount of photosynthesis and stomatal conductance in healthy and infected branches were varied depending on the position of trees, individual trees and branch type. The amount of transpiration and internal CO₂ were significantly different in healthy and infected branches. The highest amount of photosynthesis, stomatal conductance, transpiration and internal CO₂ both within and out of stand, were measured in healthy trees (except for stomatal conductance in out of stand). Both within and out of stand, healthy branch of infected tree indicates higher level of photosynthetic activity compared with infected branch. Also, twofold comparison of the four parameters investigated showed that photosynthesis, stomatal conductance, transpiration and internal CO₂ in healthy branches within stand were higher than those out of stand. It was also discovered that Viscum album caused disruption in photosynthetic activities of the host plant that, is why conducting supplementary studies in this regard is suggested to future researchers.

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Silene ghahremaninejadii (Caryophyllaceae) is described as a new species to science in this article based on critical differences in certain characters of both vegetative and reproductive organs, compared with its closely related taxa, i.e. S. marschallii and S. ruprechtii. The new species has compact caudex, glabrous leaves and pedicles, cylindrical calyx without indumentums on its inner surface, deeply bifid petals without coronal scales and glabrousfilaments. In addition, a hypothesis about the speciation process of the species is proposed.

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This investigation is a collection of studies on the breeding birds of Dez Protected Area performed from Fe-bruary 2011 to Jun 2012. During that period, field studies were executed every other 2-4 days. 5 species of native bree-ding birds including White-eared Bulbul Pycnonotus leucotis, Common Babbler Turdoides caudatus, Collared Dove St-reptopelia decaocto, Laughing Dove Streptopelia senegalensis, European Roller Coracias garrulous and 7 species of migratory breeding birds including Grey Hypocolius Hypocolius ampelinus, Great Grey Shrike Lanius excubitor, Little Ringed Plover Charadrius dubius, Red-wattled Lapwing Vanellus indicus, Pin-tailed Sandgrouse Pterocles alchata Ba-nk Swallow Riparia riparia, Blue cheeked Bea-eater Merops persicus were observed. Among the breeding birds, Coll-ared Dove S.decaocto had the most extensive breeding period from February till the early of August. Common Babbler T. caudatus (53 nests) was the frequent breeder in the terrestrial part of the Dez Protected area. Terrestrial breeding bi-rds of the area prefer habitats with Ziziphus nummularia, vegetations for breeding. Bank Swallow R.riparia with more than 300 nests was the most common species in the watery part of Dez Protected Area. They selected riparian walls for nest building. Habitat destruction was the most important threatening factor for the breeding birds.

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The species Astragalus podolobus is one of the endemic species of winter pastures that grows in arid and semi-arid areas in the north of Gonbad-e Kavous. To investigate effective methods of breaking seed dormancy of Astr-agalus podolobus, an experiment was carried out in the framework of a completely randomized design with 15 treatm-ents and 3 replications. Treatments included controls, 98% sulfuric acid, dry chilling for 10 and 15 days, wet chilling for 10 and 15 days, and boiling water 1, 3, 5, 10 and 15 minute, respectively. Analysis of variance showed that the perc-entage and speed of germination were significant in different groups while the average time of germination in different treatments was not significant. The results of comparing mean values showed that the percentage and the speed of germination in boiling water treatments were best in comparison with other treatments with significant differences. The results of this experiment also showed that reducing the exposure time of seeds to boiling water increases the germination percentage and speed, consequently, the highest percentage and speed of germination was observed in boil-ing water 1 minute. Boiling water 1 minute treatment can increase the germination percentage up to 47% and the seed germination speed from 0.43 to 3.09 seeds per day

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Saline soils are widely spread in Iran. These intact soils are a great source for the isolation of new bacteria with highly functional metabolites in biotechnology. Actinomycete strains were isolated on starch casein agar and ISP2 with different concentrations of sodium chloride (0, 5 and 10%) from treated soil samples. Pure colonies were cultured on a casein glycerol medium. After complete growth, the plates were covered with a thin layer of Muller Hinton Agar (1%) containing methicillin-resistant Staphylococcus aureus (MRSA). Active metabolites of selected strains were extracted and their antibacterial activities analyzed by agar well diffusion method. 38% of isolates produced antibiotics against the pathogen. The metabolites produced by act-2 and act-5 isolates, which had a more effective inhibition zone against MRSA, were extracted and anti MRSA activity of act-5 extract was shown. The antimicrobial activity of act-5 against other bacteria was also investigated and the bacterium was identified. In this study halophilic actinomycetes producing bioactive compounds were isolated from the saline soils of Qom and the anti-MRSA potential of their metabolites was investigated for the first time. The results of this study show the potential of saline soil actinomycetes for the production of useful metabolites.


 

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In Acidithiobacillus ferrooxidans, the proteins present in the electron transfer pathway cause ferrous iron oxidation which leads to uranium extraction. The relationship between gene sequence and uranium extraction has not been investigated yet. Based on the changes in uranium extraction, the changes of rus gene sequence can reveal the direct and accurate role of this protein. For this purpose, a random mutation was induced in native Acidithiobacillus sp. FJ2 by two doses of 0.8% and 1% of DES. Then, the bacteria was transferred into a medium which contained 50% uranium ore to carry out the bioleaching process. After measuring the amount of the extracted uranium, iron, Eh and pH, genomic DNA was extracted to investigate the rusticyanin gene (rus) sequence sent for sequencing after performing PCR. Then, the wild-type gene sequence was compared with the mutant by Bioedit v7.2.5 software. The results showed that uranium extraction increased by mutant bacteria with DES 1% between 7-11 days in comparison with wild bacteria. However, there has been no change in the functional areas of the rusticyanin gene. It seems that DES affected other effective genes in the electron transport chain or regulatory areas, which required further studies.
 



 

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The Hezar-Masjed Mountain range is one of the main highlands of the northeasten Iran. The vegetation of its upper elevations has been poorly studied. This study aimed to compare the plant biodiversity of different aspects of the Hezar-Masjed Summit. A total number of 139 random 1m² plots were recorded from different aspects of the study area. In each plot, the abundance and canopy cover percent of vascular plant species were recorded. Hill’s numbers (i.e., N₁, N₂) along with the Camargo evenness index and total species richness with bootstrapping approach were calculated. Rarefaction method was used to compare species richness among the aspects. Also, Hill’s diversity profile for each aspect was drawn. For each aspect, rank-abundance method was used to evaluate the dominant species. Biodiversity calculations and statistical analyses were performed using R software. The east- and south- facingslopes were found to have the highest and lowest indices in richness, evenness, and diversity, respectively. Despite adequate water availability in north-facing slopes, they show lower diversity than that of the east-facing slope, probably due to the of dominance of a poisonous species (Seseli transcaucasicum). Our results shown that in the Hezar-Masjed Summit, aspects have different biodiversity which is a result of their various environmental conditions.
 

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The aim of this study was to increase the shelf life of traditional yogurt, to improve its consistency and to prevent whey syneresis by adding tarragon essential oil. Yogurt was produced by industrial procedures and then the essential oil was inoculated into yogurt in different concentrations (10, 25, 30 ppm). Samples were examined for water storage capacity and microbial evaluation during 3 weeks of storage at two temperatures (refrigerator temperature and room temperature). The results showed that different concentrations of tarragon, temperature and storage time had a significant effect (p <0.05) on water holding capacity as well as the number of starter bacteria, molds, and yeasts. Tarragon essential oil reduced the number of bacteria, molds, and yeasts that spoil yogurt. The final results showed that the use of tarragon was not effective in water retention of yogurt samples, but it affected the number of initiator bacteria and yeast. Yogurt samples with high concentration of tarragon had the highest score in terms of consistency and sour taste. While samples with low concentration of tarragon, in terms of yogurt taste, had the highest sensory score.
 

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Fennel is a medicinal plant; all of its parts were being used by humans in different ways. This plant is relatively sensitive to salinity. A factorial experiment as a randomized complete block design with three replications at the greenhouse level was executed to investigate the effect of vermicompost on the increase of salinity tolerance in four fennel populations (Mashhad, Urmia, Shiraz, and Bushehr) in the vegetative stage of the plant, emphasizing the evaluation of some osmotic and antioxidant protection indicators. Experimental treatments were designed with four levels of salinity (0, 40, 80, and 120 mM of NaCl) and two levels of vermicompost (0 and 5% v/v). After harvesting, the roots were separated from the stem to analyze the biochemical variables. Salt stress caused a decrease in the total soluble sugar and starch content in the shoot and an increase of those in the root of the studied populations. In addition, under stress conditions, the proline content of shoot and root, total free amino acid, total phenol, and activity of guaiacol peroxidase and catalase were increased in fennel populations, while total soluble protein and anthocyanin content were decreased. Vermicompost treatment increased the content of soluble carbohydrates, soluble protein, free amino acids, proline, total phenol, and anthocyanin, and decreased the activity of guaiacol peroxidase in the shoot, as well as the starch content in the roots of fennel populations under non-stressed and stressed conditions. Despite observing the complexity in the changes of the analyzed indicators which were dependent on the type of population and the dose of stress, our results showed that the application of vermicompost with a concentration of 5% can improve the osmotic and antioxidant protection in the studied populations of fennel under salinity stress.