Showing 9 results for Alt
Roya Ghaffarri, Fariba Meighani, Homeira Salimi,
Volume 1, Issue 1 (12-2014)
Abstract
Mesquite is an invasive and problematic weed in warm and dry areas and so its management is very important. In order to study the effective factors on mesquite seed germination, the following studies were conducted to investigate: 1- seed viability; 2- the effect of constant temperatures on seed germination including 5, 10, 15, 20, 25, 30, 35 and 40°C independent dark and independent light conditions; 3- Effect of temperature fluctuations on seed germination including 10/0, 20/10 and 30/20°C; 4- the effect of scarification with concentrated sulphuric acid and physiacal scarification on seed germination; 5- the effect of planting depth seed on seedling emergence; 6- the effect of drought stress including 0, 100, 200, 300, 400, 500, and 600 Mm PEG on seed germination; and finally 7- the effect of salt stress including 0, 100, 200, 300, 400, 500, 600, and 700 mM NaCl on seed germination. All experiments were performed as completely randomized designs with 4 replications. The results showed that seed viability of mesquite was 81%. The optimum temperature for seed germination was a constant temperature- 30°C. In general, constant temperature was more suitable than temperature fluctuations for seed germination. The best seed planting depth for seedling emergence was 2 cm. The most seed germination was observed under the effect of 20 min scarification with concentrated sulphuric acid. Physical scarification had no significant effect on seed germination. While the study of salt and drought stresses effect showed that the most seed germination (after control without NaCl and PEG), was due to concentrations of 100 and 200 mM, seed germination decreased with the increase of NaCl and PEG concentrations. Based on the present results, light did not play a crucial role on seed germination. Therefore, mesquite seeds were not photoblastic. These characteristics are very important in making mesquite an invasive weed. Having precise information of these traits, enables us to have a better control over the management of this troublesome weed.
Hamzeh Amiri, Leila Moazzeni,
Volume 3, Issue 1 (6-2016)
Abstract
In order to study the interaction effects of salinity and ascorbic acid on the photosynthetic pigments, soluble sugar, proline, and protein in Satureja khuzestanica plant, factorial experiment was conducted in a completely randomized design (salinity in 4 levels 0, 40, 80 and 120g in 100kg soil and ascorbic acid in 2 levels 0 and 2 mM ) with 6 replicates. The results showed that salt stress reduced photosynthetic pigments amount by increasing the soil salinity from 0 to 40g NaCl in 100kg soil and then increased by 80g NaCl in 100kg soil and again decreased by concentration of 120g NaCl in 100kg soil. The amount of solouble sugar, proline and protein by the soil salinity increased from 0 to 40g in 100kg soil and then decreased in concentration of 80g NaCl in 100kg soil, in 120g NaCl in 100 kg soil increased amount of characters. In present of ascorbic acid photosynthetic pigments amount of pigments increased by increase the soil salinity from 0 to 40g NaCl in 100kg soil and then decreased by 80g NaCl in 100kg soil and again increased by concentration of 120g NaCl in 100kg soil. But, amount of solouble sugar, proline and protein by the soil salinity decreased from 0 to 40g in 100kg soil and then increased in concentration of 80g NaCl in 100kg soil. Finally, in 120g NaCl in 100kg soil decreased amount of characters.
Kobra Gholipoor, Parto Roshandel,
Volume 5, Issue 4 (12-2018)
Abstract
In order to study the diverse effects of seed priming with 24-epibrassinolide (EBL) (0, 0.1, 1 mg/l) to increase tolerance of tomato plants (Lycopersicon esculentum Mill.) to salinity (0, 70 and 140 mM NaCl), the experiments were conducted as factorial based on completely randomized design at greenhouse condition. Results showed that salt stress significantly decreased the growth of tomato plants. However, priming with EBL (1 mg/l) significantly decreased the negative effects of NaCl (particularly at 140 mM). At this case, EBL increased the fresh and dry weights (<2 folds), total chlorophyll (+72%), carotenoids (+ 2 folds), free proline (+3 folds), electrolyte leakage (-18.6%), Na+/K+ in the roots (-57.5%) and shoots (-62%) compared to salinity control. Generally, it could be concluded that priming with epibrassinolide resulted in enhanced salt tolerance in tomato plants via increment in free proline, photosynthetic pigments and decrease in electrolyte leakage and Na+/K+ ratio in the tissues.
Maryam Khezri,
Volume 6, Issue 1 (5-2019)
Abstract
Bacterial communities are able to form complex and three-dimensional biofilm structures. Biofilm formation is an ancient and integral component of the prokaryotic life cycle and a key factor for survival in diverse niches. In biofilms, bacterial lifestyle changes from free-floating cells to sessile cells. Presence in biofilms gives new traits to bacteria, which distinguish them from free cells. The presence of bacteria in biofilms results in high resistance to antimicrobial treatments and oxygen deficiency. Biofilms are formed in response to different environmental signals and many genes are involved in their production. Biofilms can be problematic in fluid transfer pipelines, on medical devices, as well as implants in the patients’ bodies. However, they can be applied for useful purposes such as treating industrial and agricultural wastewater, bioremediation of heavy metals and in air pollution biofilter systems. The potential of forming biofilms in pathogenic bacteria is an advantage for their survival in unfavorable conditions, and cause a lot of problems in their removal as the bacteria show more resistant to antibiotics and chemical pesticides in biofilms compared with free living cells. The ability to form biofilms in plant-beneficial rhizobacteria used for plant disease biocontrol, plant growth promotion and the improvement of agricultural products quality is an important advantage especially in their mass production and commercializing process. Considering the importance of bacterial biofilms in human life, this paper evaluated the importance of biofilms from different aspects.
Seyed Mousa Mousavi Kouhi, Maryam Moudi, Esmael Soltani Moghadam, Hedyieh Sarchahi Moghadam,
Volume 6, Issue 1 (5-2019)
Abstract
The identification of the characteristics of native halophytic species is very important for their practical application. The present study was carried out to identify the halophytic species of a desert and highly saline region around the city of Khosf, southern Khorasan Province, and to detect their general tolerance mechanisms (i.e. salt exclusion or inclusion). Sodium accumulation in the roots and shoots of seven species, including Launaea arborescens, Peganum harmala, Pteropyrum olivieri, Artemisia santolina, Zygophyllum eurypterum Boiss, Aerva javanica, Pulicaria gnaphalode, and their rhizosphere soil were determined. The bioconcentration of sodium from soil to roots (BCF), its translocation from roots to shoots (TF), and its accumulation in the shoots (AF) were then calculated. Results showed that the soil of the studied area was clay loam with a high EC of 65 ds/m, indicating its high salinity level. According to the values of sodium adsorption ratio (SAR) and the exchangeable sodium percentage (ESP) and regarding EC, the soil of studied region can be regarded as a saline-sodic soil. The value of TF in some species was higher than 1. However, none of the species had BCF and AF greater than 1, thus, none of them could be considered to be salt accumulator. Instead, it could be assumed that all of the studied species were salt, or at least, sodium excluders.
Hadiseh Esfade, Ghadireh Mirabolghasemi, Mahnaz Azarnia,
Volume 6, Issue 2 (8-2019)
Abstract
Diabetes mellitus is known to be resistant to insulin, to dysfunction of beta cells and to increase liver glucose production. Poor glucose control during hyperglycemia causes damage to the tissues and creates dangerous consequences, such as infertility. Chronic hyperglycemia has harmful effects on the growth of follicles, which is essential for normal female sexual function. Metformin is the most widely prescribed drug in diabetes, but chemical drugs, despite their undeniable benefits, have destructive effects, so alternative strategies for current modern diabetes medications are essential. Herbal medicines are widely used by patients, based on non-medical recommendations and as blood-glucose-lowering agents, including the nettle. Nettle contributes to lower plasma glucose levels by secreting insulin and increasing the proliferation of beta cells in the pancreas. Therefore, the aim of this study was to determine the effect of nettle extract as a supplement of metformin on ovarian tissue of diabetic model. In this experimental study, 30 female Wistar rats were used. Animals were weighed and randomly divided into 5 groups (n=6). 1) control group 2) diabetic group who were diabetic with intravenous injection of alloxan (150 mg / kg) 3) diabetic group + Nettle root extract (150 mg / kg) 4) diabetic + metformin (150mg / kg) 5) Diabetic group + Metformin(150 mg / kg) + Nettle root extract(150 mg / kg). At the end of treatment, the effect of metformin and nettle root extract on ovarian tissue and biochemical factors such as blood glucose and sex hormones were compared and the data obtained were analyzed by SPSS. Hyperglycemia and body weight loss after metformin and nettle root increased for 4 weeks. Simultaneous administration of metformin and extracts of nettle root significantly increased the primordial, primary, secondary, and corpus luteum and reduced the atretic follicles and significantly increased FSH, LH and testosterone levels as compared with metformin alone. The results of this study showed that the root of nettle with its antioxidant compounds and other properties could be a complement to metformin with a corrective effect on hyperglycemia and the improvement of ovarian disorders.
Mehrnoush Daneshvar, Mahmood Maleki, Shahryar Shakeri, Amin Baghizadeh,
Volume 6, Issue 4 (12-2019)
Abstract
Phosphorus, the most essential nutrient for plants, becomes quickly unavailable for the plants in the soil. Phosphate solubilizing bacteria (PSB( can play an important role in providing Phosphorus for plants. In this study, the PSBs were screened from plant rhizosphere by Pikovskaya method. Then, the growth rate and phosphate solubilizing ability of 9 superior strains were measured at different temperatures and levels of salinity and pH. The best strain was identified by 16S rDNA gene sequence analysis. Finally, the genetic diversity of phosphate solubilizing strains were examined by RAPD markers. Results showed that 25 strains were capable of solubilizing insoluble phosphates among the 57 isolates studied. Of the nine superior strains, Cke1 had the highest solubilizing index with the average growth rate under all conditions and was introduced as the best PSB strain identified in the present study. 16S rDNA gene sequence analysis showed that this strain belonged to the Enterobacter genus. The results of genetic variation showed that all stains were divided into six groups and three strains that had the lowest similarity with other strains were placed in three separate groups. Given that Cke1 strain has the ability of solubilizing the insoluble phosphate in different stresses, it can be a good candidate for providing phosphorus at temperatures of 30 and 35 °C, 1.2% and 1.8% salinity levels and pH levels of 6 and 8 for the crops.
Shabnam Heidarpour, Nasser Abbaspour, Nayer Mohammadkhani, Sanaz Mosavi Pornaki,
Volume 7, Issue 4 (12-2020)
Abstract
Salinity tolerance of four grape genotypes [GharaUzum, Hosseini, AghUzum and Keshmeshi] was studied under various salinity levels (25, 50 and 100 mM NaCl). As a result, growth indices were significantly (P<0.05) reduced by salinity, whereas Cl- and Na+ contents in the plant parts were increased. Cl- accumulation exceeded than that of Na+ in all treatments. Among the genotypes studied, GharaUzum and Keshmeshi had the lowest and highest Cl- concentrations in the leaf lamina, respectively. Photosynthesis and transpiration rate as well as stomatal conductance were greatly reduced by salinity and were shown to be highly correlated with leaf Cl- content. GharaUzum showed lower reduction in photosynthesis parameters. Soluble sugars, proline and glycine betaine contents increased in the leaf lamina of all the genotypes studied treated with moderate salinity (50 mM). In conclusion, the results showed that GharaUzum and Keshmeshi had the highest and lowest salt stress tolerance among the genotypes studied, respectively.
Manoj Kumar, Rakesh Ranjan, Amar Kumar, Manoranjan Prasad Sinha, Rohit Srivastava, Sweta Subarna, Samir Kumar Mandal,
Volume 7, Issue 4 (12-2020)
Abstract
Punica granatum leaf extracts have been used since time immemorial in traditional medicines. It is used for its antioxidant properties. Green nanoparticle synthesis is an emerging field which has opened an entirely different scope for medicinal formulations. It has been reported by many users that the green nanoparticles are more effective medicines as compared with their simple extracts. Thus, in order to evaluate these speculations, the present work was undertaken to assess the hepatoprotective activity of silver nanoparticles synthesized using aqueous leaf extract of Punica granatum in comparison with the aqueous extract. After CCl4 intoxication the serum bilirubin total increased significantly (p<0.05) and the total protein level decreased significantly (p<0.05) as compared with the control group; in addition, alkaline phosphatase activity, aspartate aminotransferase activity and alanine transaminase activity increased significantly (p<0.05). The CCl4 intoxicated rats were treated with aqueous leaf extract and synthesized nanoparticles, the results clearly revealed that the aqueous extract of Punica granatum showed hepatoprotective effect, as the liver profile altered by CCl4 toxicity, recovered to normal control values. Moreover, the nanoparticles synthesized using aqueous leaf extract of Punica granatum were comparatively more effective as hepatoprotective agent than the aqueous extract of Punica granatum.
