Changes induced by osmotic stress in the morphology,biochemistry, physiology,anatomy and stomatal parameters of almond species （Prunus L. spp.） grown in vitro

We investigated the influence of different levels of osmotic stress on growth and development in selected wild almond species(eight Prunus spp.) grown in vitro. The study, while endorsing the efficacy of in vitro screening of auxiliary buds of wild almond for osmotic stress tolerance, showed species variability in its response to osmotic stress. Osmotic stress reduced growth and development of all the species. However, the putative tolerant Prunus spp. showed better performance than the putative susceptible genotypes. On average there was an 80% decrease in shoot dry weight at-1.2 MPa. Reduction in shoot weight was more common in osmotic stress-susceptible species in the section labeled ‘Euamygdalus'. The tolerant Prunus species produced smaller changes in biochemical responses than the sensitive cultivars for malondialdehyde content, catalase activity, relative permeability of protoplast membranes, and net photosynthetic rate. The tolerant species maintained cell integrity better than drought sensitive species. Wild almond species in the section labeled ‘Spartioides'(Prunus arabica(Olivier) Neikle, Prunus glauca (Browicz) A.E. Murray, Prunus scoparia Spach) and ‘Lycioides'(Prunus lycioides Spach, Prunus reuteri Bossi. et Bushe) were best adapted to osmotic stress. Increase in chlorophyll concentration and leaf thickness under high osmotic stress can be considered as preliminary selection parameters for osmotic stress tolerance in Prunus spp. The study confirmed the efficacy of the in vitro method for screening of large number of genotypes for osmotic stress tolerance in wild almond species.     

Effects of nickel and PGPBs on growth indices and phytoremediation capability of sunflower (Helianthus annuus L.)

The effect of bacteria inoculation was studied on sunflower growth and phytoremediation capacity in soils contaminated by different levels of nickel. The experimental treatments consisted of four levels of bacteria inoculation – non-inoculated, inoculated by Bacillus safensis, inoculated by Kocuria rosea, and co-inoculated by B. safensis + K. rosea – and four levels of nickel concentrations in the soil – Ni0, Ni150, Ni300, and Ni450 (0, 150, 300, and 450 mg Ni per kg soil, respectively). The treatments were arranged as factorial structure based on a completely randomized design. Results have shown that growth indices, photosynthetic pigments, shoot Fe concentration, root and shoot Zn concentration, and translocation factor decreased as the Ni concentration in soil increased. Shoot and root Ni concentration were higher at Ni450, whereas, the highest Ni uptake by the plant was observed at Ni300 when the sunflower seed was co-inoculated by B. safensis + K. rosea bacteria. Bacteria inoculation significantly increased the plant growth, photosynthetic pigments, and Ni uptake. By B. safensis inoculation, the Fe concentration significantly increased in shoot, while it decreased in root.     

Effects of plant growth-promoting bacteria on the phytoremediation of cadmium-contaminated soil by sunflower

This paper describes the effect of plant growth-promoting bacteria on sunflower growth and its phytoremediation efficiency under Cd-contaminated soils. Four levels of bacteria inoculation (non-inoculation, inoculation by Bacillus safensis, Kocuria rosea and co-inoculation by Bacillus safensis+Kocuria rosea) and four Cd concentrations (0, 50, 100 and 150 mg Cd per kg soil) were arranged as factorial experiment based on a completely randomized design (CRD). Results showed that Cd significantly decreased growth by decreasing the shoot and root length and biomass (p < 0.01). In addition, Cd dramatically decreases photosynthetic pigments, Fe transport to shoot and Zn uptake (p < 0.01). Bacterial inoculation increased Fe and Zn uptake by plants, Cd concentration in the aboveground part of plants and Cd uptake by the enhancement of Cd concentration in plant tissue and biomass production. Results showed that the highest shoot Cd uptake was ?observed in ?inoculated plants by Bacillus safensis at Cd100 (20.35 mg pot^?1). However, in average of Cd treatments, the performance of co-inoculation in Cd uptake (13.04 mg pot^?1) was better than singular inoculation (10.68 and 12.58 mg pot^?1 for Bacillus safensis and Kocuria rosea, respectively). Results revealed that bacterial inoculation increased the Cd uptake performance in shoot and total biomass by 30% and 25%, respectively.     

An integrative study of Sakia sisanganensis n. sp. (Rhabditida: Tylenchidae) from Sisangan forest,Iran, and new morphological observations for the genus

Further data on the morphology (the lip region characters) and phylogeny of the genus Sakia are presented. The new observations were based on scanning electron microscopy (SEM) and light microscopy (LM). A new species, Sakia sisanganensis n. sp., was recovered from rotten wood of a dead beech tree (Fagus orientalis) in northern Iran, herein described and illustrated based on an integrative approach, that is morphological, morphometric and molecular characters. The new species is characterized by a combination of the following features: fine transverse striae and vestigial single band in the lateral field in SEM. Labial area dorso‐ventrally flattened. Oral region with two concentric hexagonal plates, the inner one apparently elevated. Amphidial openings short, slit‐like. Stylet delicate. Median bulb fusiform to spindle‐shaped with weak valvular apparatus. Spermatheca functional. Tail filiform with faintly pointed tip and males common. The new species was morphologically compared with four known species of the genus, viz., S. alii, S. arboris, S. castori and S. indica, all having indistinct lateral fields. Molecular phylogenetic analyses were performed based on the small subunit ribosomal RNA gene (SSU rDNA). In the Bayesian inference (BI), S. sisanganensis n. sp. with two isolates was strongly supported as a sister taxon of a clade harbouring S. arboris + Lelenchus species. However, in the maximum likelihood (ML) analysis, the new species formed a clade with S. arboris, thus supporting the reciprocal monophyly of the genera Sakia and Lelenchus. Accordingly, the test of monophyly was performed (using Bayes factor) and the results did not reject the monophyly of sakia (i.e., S. sisanganensis n. sp. and S. arboris as sister taxa) based on the currently available data.     

Comparison of distribution of virulence determinants in clinical and environmental isolates of Vibrio cholera

Background: The virulence of a pathogenic Vibrio cholerae is dependent on a discrete set of genetic determinants. In this study, we determined the distribution of virulence determinants among the clinical and environmental isolates of V. cholerae. Methods: The antibiotic resistance profiles of the isolates were determined using standard disk diffusion assay. PCR assay was performed to analyze the presence of toxin genes of ctx, zot and ace. The composition of cholera toxin encoding element (CTX) region flanking of the V. cholerae isolates was also analyzed. Results: All of the clinical isolates (100%) showed a complete set of virulence genes and also the attachment site of the filamentous bacteriophage CTXphi. None of the environmental isolates contained the virulence genes and the attachment site of the CTXphi. Analysis of the flanking regions including the toxin-linked cryptic element and repeat in toxin genes revealed their integrity in the clinical isolates while in the environmental isolates they were absent or contained incomplete sequences. Comparison of the antibiotic resistance assay of the environmental and clinical isolates showed a significant difference in the resistance profiles of the isolates obtained from the two sites. High rates of resistance to co-trimoxosol, streptomycin and chloramphenicol were found with clinical isolates. Conclusion: The absence of all virulence determinants in the environmental strains may suggest that certain ecological features must be present for V. cholerae to acquire a complete set of virulence determinants and to turn them into pathogenic strains.     

Three-dimensional finite element modelling of heat transfer for linear friction welding of Scots pine

Finite element numerical analyses were performed to determine three-dimensional heat flux generated by friction to wood pieces during linear friction welding. The objective was to develop a computational model to explain the thermal behaviour of welded wood material rather than experimental methods, which are usually expensive and time consuming. This model serves as a prediction tool for welding parameters, leading to optimal thermo-mechanical performance of welded joints. The energy produced by the friction welding of small wood specimens of Scots pine (Pinus sylvestris L.) was determined by thermocouples and used as input data in the model. The model is based on anisotropic elasticity and the thermal properties were modelled as isotropic. This numerical simulation gave information on the distribution of the temperature in the welding interface during the entire welding process. A good agreement between the simulation and experimental results showed the appropriateness of the model for planning welded wood manufacture and prediction of thermal behaviour of wood during other mechanically induced vibration processes. The specimens presented in this model required a heat flux of 11 kW/m² to achieve a satisfactory welding joint.     

Phenotypic diversity and relationships of fruit quality traits in inter-specific almond × peach backcrosses breeding progenies

Nineteen agrochemical traits of 20 almond inter-specific backcrosses progenies were evaluated and compared for three consequence years to find out their phenotypic diversity and determine the relationships of fruit quality traits in almond × peach backcrosses breeding progenies. The variation was observed for traits of phenology parameters (blooming time, ripening time), Physical parameters (fruit weight, width, height, shape, thickness, skin pubescences, colour and flower type), chemical parameters (total sugar content, soluble solids content and acidity) and sensory parameters (attractiveness, taste, and flavor) and yield. Many fruit characteristics that are important to breeders are present in this collection. A high variability was found in the evaluated almond progenies and significant differences were found among them in all studied quality attributes. Year-by-year variations were observed for majority of traits. A significant correlation was found among the fruit height, fruit width, skin pubescences and yield. Fruit height showed a significant positive correlation with fruit weight and fruit thickness and some other traits and a negative correlation with the titratable acidity, skin pubescences and fruit flavour. A high negative correlation was found between the fruit weight and titratable acidity (?0.8). Low coefficients were got between the flower colour and skin pubescences. In addition, principal component analysis it possible to established similar groups of genotypes depending on their quality characteristics and to study relationships among pomological traits in almond progenies evaluated.     

Tree species could have substantial consequences on topsoil fauna: a feedback of land degradation/restoration

The characteristics of the faunal community in the soil are closely related to soil quality and function. Land degradation, which reduces vegetation cover, may affect the soil surface-active fauna because both the above ground and below ground invertebrates depend on complex plant communities. In this study, we evaluated the effect of land degradation/restoration and factors affecting soil fauna in northern Iran. The studied land uses were virgin natural forest (VNF), Alnus subcordata C.A.M. plantation (ASP), Quercus castaneifolia C.A. Mey plantation (QCP), Cupressus sempervirens var. horizontalis plantation (CSP) and degraded natural forest (DNF). VNF and ASP enhanced soil earthworm density (2.43 and 2.12 ind. m^?2) and dry mass (27.44 and 23.39 mg m^?2) with more ratio of epigeic. The activities of acarina (91,851.37 and 85,810.43 ind. m^?2), collembola (83,009.50 and 74,996.18 ind. m^?2) and protozoa [921.25 and 851.81 (×?10² g soil)] were increased under VNF?≈?ASP, respectively. Nematode population (650 in 100 g soil) significantly improved under VNF. In general, good quality forest floor, alkaline soil and accumulation of macro-element nutrients improved biological activities under the VNF and ASP sites, while low-quality forest floor, acidic soil, less macro-elements nutrients decreased biological activities imposed by the QCP, CSP and DNF sites. More activities of the studied soil fauna were found in autumn and spring. The findings of this study support the importance of preserving natural forests. In addition, employing N₂-fixing and suitable native broadleaved species have been proposed in a bid to rehabilitate DNFs.     

Molecular Investigation of Human Cytomegalovirus and Epstein-Barr virus in Glioblastoma Brain Tumor: A Case-Control Study in Iran

Background:Glioblastoma multiforme is the most invasive and lethal form of brain cancer with unclear etiology. Our study aimed to investigate the molecular prevalence of HCMV and EBV infections in patients with GBM. Methods:This case-control study was conducted on 42 FFPE brain tumor samples from GBM patients and 42 brain autopsies from subjects without neurological disorders. The presence of EBV and HCMV DNA was determined, using PCR and nested-PCR assays, respectively. Results:HCMV DNA was detected in 3 out of 42 (7.1%) of GBM samples and was absent from the control group (p = 0.07). Importantly, EBV DNA was detected in 9 out of 42 (21.4%) brain tissue specimens of GBM subjects, but again in none of the control group (p = 0.001). Conclusion:Our findings indicate that infection with EBV is associated with GBM. Key Words: Brain tumor, Epstein-Barr virus, Glioblastoma, Human cytomegalovirus