Omid Younesi; Ali Moradi
Abstract
This study investigated the influence of inoculation with an arbuscular mycorrhizal fungus (AMF), Glomus mosseae (Nicol & Gerd.) on growth and antioxidant enzyme activities (SOD, CAT, GUPX) in shoots and roots of wheat (Triticum aestivum L.) affected by three different levels of salt stress. The ...
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This study investigated the influence of inoculation with an arbuscular mycorrhizal fungus (AMF), Glomus mosseae (Nicol & Gerd.) on growth and antioxidant enzyme activities (SOD, CAT, GUPX) in shoots and roots of wheat (Triticum aestivum L.) affected by three different levels of salt stress. The experiment was arranged as a factorial in Randomized Complete Block Design (RCBD) with three replications. Experimental treatments including: three levels of salinity stress (0 (control), 60 and 120 µm) and two levels of inoculation (inoculation and non inoculation). Salinity decreased wheat growth, regardless of the mycorrhizal treatment and the salt stress level. The plants inoculated with AMF had significantly greater shoot biomass than the control plants at all salinity levels. However, the results pointed out that salinity had inhibitory effects on mycorrhizal infection. The highest mycorrhizal infection was observed in the control plants. Increasing salinity stress raised significantly the antioxidant enzyme activities, including those of total SOD, GUPX and CAT, of wheat compared to their respective non-stressed controls. The AMF induced a higher increase in these antioxidant enzymes in response to severe salinity. Inoculation with AMF could serve as a useful tool for alleviating salinity stress in salt-sensitive plants. However, Analysis of variance indicated that there was not significant interaction between salt and mycorrhizal inoculation on SOD and CAT of roots. Also, there was not significant interaction between salt and mycorrhizal inoculation on GUPX in both shoots and roots.
Hossein Monjezi; Mohammad Moradi Telavat; Seyyed Ataollah Siadat; Ahmad Koochakzadeh; Hassan Hamdi
Abstract
Filter mud is a residual of sugar extraction process produced in huge volume and has high organic matter and essential elements. Regarding to these properties, it seems this material could be a useful fertilizer in crop production. To evaluate effect of sugarcane filter muds and chemical and biological ...
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Filter mud is a residual of sugar extraction process produced in huge volume and has high organic matter and essential elements. Regarding to these properties, it seems this material could be a useful fertilizer in crop production. To evaluate effect of sugarcane filter muds and chemical and biological fertilizers application on canola (Brassica napus L.) yield and some of soil properties, a factorial experiment was conducted in 2012 in experimental farm of Ramin (Mollasani) Agriculture and Natural Resources University of Khouzestan. A complete block design was used for the experiment in three replications. Different integrated treatments of filter muds and chemical fertilizers including A1: 100 percent filter muds, A2: 75 percent filter muds and 25 percent chemical fertilizers, A3: 50 percent filter muds and 50 precent chemical fertilizers, A4: 25 percent filter muds and 75 percent chemical fertilizers and A5: 100 percent chemical fertilizers were investigated as an experimental factor. Other experimental factor was biological fertilizers application (with and without biological fertilizers). The biological fertilizers investigated in this study were included nitroxin and Barvar 2. Application of filter muds had significant effects on canola yield, yield components, grain oil and protein contents. The soil organic matter and salinity also were affected by filter muds significantly. Highest canola grain yield was obtained by integration of filter muds and chemical fertilizers. Increase of filter muds caused to increase of grain oil content and decrease of nitrogen and nitrate content. On the other hand, increase of chemical fertilizers increased nitrate and nitrogen contents and decreased oil content. In addition, increase of filter muds resulted in higher soil organic matter and salinity, simultaneously.
Mehdi Rezaei; Abass Rohani
Abstract
Stomatal resistance has an important role in plant water exchange and photosynthesis under stress condition hence it is a key parameter in ecological and biological models. In the present research, optimum values of effective parameters on stomatal resistance of olive to achieve maximum stomatal resistance ...
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Stomatal resistance has an important role in plant water exchange and photosynthesis under stress condition hence it is a key parameter in ecological and biological models. In the present research, optimum values of effective parameters on stomatal resistance of olive to achieve maximum stomatal resistance were determined. Salinity levels (0, 25, 50 and 100 mg/l NaCl), percentage of leaf ions (chlorine, sodium, potassium, calcium, phosphor, magnesium), K/Na ratio, wet weight of leaf (mg), leaf area (cm2), relative water content (%) and leaf area ratio (cm2/g) were considered as effective parameters in stomatal resistance of olive. The stomatal resistance was modeled as a function of the variables using a radial basis function (RBF) neural-network model. The predicted results demonstrated that the neural network could provide a good performance since prediction results were in rather good agreement with measured results. The maximum percentage error between predicted and experimental data was less than 2.57% and the correlation coefficient between them was 0.994. Also, the statistical comparison between the predicted and experimental data indicates the reliability of the predictions using a RBF neural-network model. The trained neural network is used as objective function to get optimal parameters using the genetic algorithm. The optimum values of the parameters obtained at a 100, 0.15, 0.57, 0.78, 0.32, 0.06, 0.17, 1.29, 26.63, 5.03, 0.76 and 72.89 for the first parameter through the last parameter, respectively.
Omid Younesi; Kazem Poustini; Mohammad Reza Chaichi; Ahmad Ali Pourbabaie
Abstract
In order to study the effects of seed-bacterial priming (inoculation) on germination and early growth of alfalfa under salinity stress conditions, an experiment was conducted at seed research laboratory and Greenhouse of College of Agriculture, University of Tehran in Karaj (Iran) in 2011. The experiment ...
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In order to study the effects of seed-bacterial priming (inoculation) on germination and early growth of alfalfa under salinity stress conditions, an experiment was conducted at seed research laboratory and Greenhouse of College of Agriculture, University of Tehran in Karaj (Iran) in 2011. The experiment was arranged as a factorial in Completely Randomized Design (CRD) with three replications. Experimental treatments including: three levels of salinity stress (zero (S0), 60 (S1) and 120 (S2) mmol), two levels of alfalfa cultivars (‘Bami’ and ‘Yazdi’) and 16 levels of bacterial priming (Azetobacter, Azospirillum, Pseudomonas and Rhizobium meliloti in single and different double, triple and quadratic integrated forms). The results indicated that applying salinity stress significantly decreased germination and early seedling growth. This descending trend in control (no inoculation) treatment was more than that of treated seeds. Application of bacterial priming especially Pseudomonas priming and integrated treatments played an important role in moderating the negative effects of salinity on measured traits. According to the results of this study, it seems that plant growth promoting bacteria, by producing and releasing phytohormones such as auxin, gibberellins and cytokinin along with decreasing ethylene level, improve plant growth under salinity stress condition.