Optimization of medium composition for apple rootstocks

Impact of medium composition (plant growth regulators, mineral nutrients) on multiplication rate, shoot elongation, callusing and rooting of apple rootstocks ('M9', 'M27', and 'MM106') cultured on gelled basal Murashige and Skoog (MS) medium were investigated. Multiplication rate was mainly dependent upon kind of plant growth regulators especially, 6-benzylaminopurine (BA), mineral concentration and genotypes. The best shoot production in terms of shoot number and shoot quality was obtained using 4.4 μM BA and 2.27 μM thidiazuron (TZD) during the shoot multiplication phase, but 8.8 μM BA + 1.14 μM TZD and 2.8 μM gebberllic acid (GA3) during the shoot elongation phase for all genotypes. Application of high (2.8 μM) concentration of GA3 increased the elongation of adventitious shoots than low concentrations. The highest multiplication rate (5.7 No.//shoot) and the highest amount of total fresh weight (2.25 g/jar), as growth rate, were produced by applying 4.4 μM BA + 2.27 μM TDZ for ‘M27’ genotype. Micropropagation potential of ‘M27’ genotype was higher than other genotypes. 'MM106' genotype had the lowest multiplication rate (0.7 No./month), when 0 μM BA+9.08 μM TDZ was applied. Multiplication of explants from the 1st subculture was more sensitive to BA than that from the 3th or 4th subculture. The rooting of explants was promoted by indole-3-butyric acid (IBA) significantly and the best result for rooting was achieved in the half-strength MS medium containing 5.4 μM IBA and 1.2 μM 2,4-dichlorophenoxyacetic acid (2, 4-D). The highest percentage (64%) rooting was produced for ‘MM106’ genotype and the lowest (11%) for ‘M9' after 3 months. Root formation was increased with decreasing concentrations in cytokinins, but increasing auxins (IBA). Rooting percentage of shoot cultures in the low 1/2X-MS medium was significantly more than shoot cultures in the high 2X-MS medium.Key words: Apple rootstocks, medium composition, multiplication rate, plant growth regulators (PGRs)

Protective Role of α-Pinene in Cuprizone-Induced Multiple Sclerosis in Mice

Introduction: It is clamied that α-pinene has properties against Multiple Sclerosis (MS) which is known as demyelination of the neurons. Given that, the aim of this study was to investigate the effect of α-pinene on Cuprizone-induced (CPZ) MS. Materials and Methods: A total of forty C57BL/6 mice were allocated to 4 groups. Mice in group 1 (control) were treated with a normal diet. In group 2, CPZ-induced demyelination was done by chew palate containing .2% (w/w) CPZ for 5 weeks. In group 3, a normal diet was provided and mice were injected with -pinene (1 mg/kg; i.p.) 3 times a week for 5 weeks. In group 4, mice were fed with the CPZ containing diet and injected with -pinene (1 mg/kg; i.p.) three times a week for 5 weeks. At the end of the study, reflexive motor behavior and depressive- like behavior tests were performed. Additionally, serum anti-oxidant activity was determined. Results: Results show that the CPZ had an adverse effect on reflexive motor behavior tests (P<.05) and co-administration of the CPZ+-pinene diminished the adverse effect of the CPZ on the reflexive motor behavior tests (P<.05). Moreover, CPZ significantly amplified immobility time (P<.05) and co-administration of the CPZ+-pinene reduced the adverse effect of the CPZ on depressive-like behavior tests (P<.05). CPZ significantly increased malondialdehyde (MDA) and decreased glutathione peroxidase (GPx), superoxide dismutase (SOD) and total antioxidant status (TAS) and also these effects were reversed by α-pinene (P<.05). The data indicate that co-administration of the CPZ+-pinene significantly improved the adverse effect of the CPZ on serum antioxidants (P<.05)

Chemical composition, antibacterial and antifungal activity of three ecotypes of Thymus fallax Fisch. volatile oils

Background and Aims: Thymus fallax Fisch. is an aromatic plant belonging to the Lamiaceae family, used for medicinal and spice purposes almost everywhere in the world. In this investigation volatile oils from three ecotypes of T. fallax have isolated using a Clevenger-type apparatus. Methods: The quantitative and qualitative analysis was performed by gas chromatography/Mass spectroscopy (GC and GC/Mass). Antibacterial activity of compounds was assayed using the disc diffusion method against G- and G+ bacteria and some fungi pathogenesis. Results: Final results shows that Thymol & carvacrol constitute of the main elements present in the essential oil of T. fallax. In Lamiaceae plants, thymol is always accompanied by its isomer carvacrol. Both compounds are biologically active and have potent antibacterial (gram+ and gram-) and anti fungal activity. The essential oil exhibited strong antioxidant activity. Conclusions: Recognized compounds of Thymus fallax Fisch. volatile oils are biologically active and have potent antibacterial (gram+ and gram-) and anti fungal activity. This study also affirmed three ecotypes volatiale oil had significant effects against G- and G+ bacteria and some fungi pathogenesis

Assessment of Two Different Sources of Durable Resistance and Susceptible Cultivar of Wheat to Stripe Rust (Puccinia striiformis f. sp. tritici)

A study was conducted to assess the durable resistance in a near isogenic line of spring wheat (Triticum aestivalis L.), possessing resistance gene Yr-18 to some isolates (race specific resistance) of stripe rust (Puccinia striiformis f. sp. tritici), namely Thatcher Yr-18 and durable resistance of an cultivar of spring wheat to all isolates of stripe rust (race non- specific resistance), namely Hybrid de Berse'e. In this investigation fresh urediniospores of two isolates namely SRC 99 (race 70E 128) and SRC 89 (race 14E 14), were collected from a susceptible cultivar of spring wheat, Avocet, as inoculums. Then suspension of spore in mineral oil [Soltrol 170 (5 mg/ml)] were sprayed on third and flag leaves of the booth genotypes mentioned above and on the Thatcher cultivar which was susceptible to booth isolates. The Percentage of urediniospore germination, latent period and infection types of all susceptible and resistant genotypes to booth isolates were determined in four replicates at seedling and adult plant stages. Mean percentage of spore germination and the value of latent period were analyzed separately in each replicate, and then compared using analysis of variance and the Student- Newman Keuls test. The results indicated that urediniospoe germination in all genotypes / isolates/ leaf stage combination was high and neither resistance type affected spore germination significantly. In both types of resistance, latent period increased with advancing plant age. In general cultivars possessing resistant gene had longer latent periods. Assessment of the infection type showed that, the durable resistance of Hybrid de Bers?e is detected at an earlier stage than the adult-plant resistance of near isogenic line containing the gene Yr18

Modeling of NiTiHf Using Finite Difference Method

NiTiHf is a high temperature and high strength shape memory alloy with transformation temperatures above 100oC. A constitutive model based on Gibbs free energy is developed to predict the behavior of this material. Two different irrecoverable strains including transformation induced plastic strain (TRIP) and viscoplastic strain (VP) are considered when using high temperature shape memory alloys (HTSMAs). The first one happens during transformation at high levels of stress and the second one is related to the creep which is rate-dependent. The developed model is implemented for NiTiHf under uniaxial loading. Finite difference method is utilized to solve the proposed equations. The material parameters in the equations are calibrated from experimental data. Simulation results are captured to investigate the superelastic behavior of NiTiHf. The extracted results are compared with experimental tests of isobaric heating and cooling at different levels of stress and also superelastic tests at different levels of temperature. More results are generated to investigate the capability of the proposed model in the prediction of the irrecoverable strain after full transformation in HTSMAs

The prediction model for additively manufacturing of NiTiHf high-temperature shape memory alloy

NiTi-based alloys are one of the most well-known alloys among shape memory alloys having a wide range of applications from biomedical to aerospace areas. Adding a third element to the binary alloys of NiTi changes the thermomechanical properties of the material remarkably. Two unique features of stability and high transformation temperature have turned NiTiHf as a suitable ternary shape memory alloys in various applications. Selective laser melting (SLM) as a layer-based fabrication method addresses the difficulties and limitations of conventional methods. Process parameters of SLM play a prominent role in the properties of the final parts so that by using the different sets of process parameters, different thermomechanical responses can be achieved. In this study, different sets of process parameters (PPs) including laser power, hatch space, and scanning speed were defined to fabricate the NiTiHf samples. Changing the PPs is a powerful tool for tailoring the thermomechanical response of the fabricated parts such as transformation temperature (TTs), density, and mechanical response. In this work, an artificial neural network (ANN) was developed to achieve a prediction tool for finding the effect of the PPs on the TTs and the size deviation of the printed parts

A COMPLIANT ANKLE-FOOT ORTHOSIS (AFO) BASED ON MULTI-AXIAL LOADING OF SUPERELASTIC SHAPE MEMORY ALLOYS

ABSTRACT This paper presents a novel actuation solution to address the drop foot disorder. The proposed actuator consists of a superelastic Nitinol rod with a variable torsional stiffness that is adjusted by the controlled application of an axial load. The superelastic SMA element enables the AFO to provide sufficient torque during dorsiflexion to raise the foot. The provided torque at the ankle joint assists the patient in walking more naturally and subsequently prevents further issues such as muscle atrophy. By appraising experimental data of the human gait, ankle stiffness is assessed in order to compare ankle behavior for various walking speeds during the swing phase. The adjustable compliance concept for the AFO is then explained, followed by a description of the actuation mechanism and complex loading configuration. Numerical modeling is also presented for the superelastic element of the AFO under specified multiaxial torsion-tension loading. Simulations are performed in MATLAB and variable stiffness results are compared with experimental data for verification