Soil science
K. Asadzadeh; H. Nadian; A. Siahpoosh; V. Keshavarz-Tohid
Abstract
Background and Objectives: In recent years, the production of healthy foods through environmentally friendly methods has received much attention. Spinach is a vegetable plant rich in minerals and vitamins which is used in green and cooked forms. Thus, healthy production of this plant with the greatest ...
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Background and Objectives: In recent years, the production of healthy foods through environmentally friendly methods has received much attention. Spinach is a vegetable plant rich in minerals and vitamins which is used in green and cooked forms. Thus, healthy production of this plant with the greatest quantitative and qualitative yield is of particular importance. Weeds as unwanted plants in spinach fields can damage this plant significantly. Nevertheless, spinach is severely sensitive to different herbicides. The goal of this study was to investigate the effect of plant growth promoting rhizobacteria (PGPR), filter cake and metribuzin herbicide on growth and mineral nutrition of spinach plant. In this study, the growth and nutritional parameters of spinach interact with PGPR, filter cake and metribuzin herbicide was also aimed.Materials and Methods: The spinach seeds (Spinacia oleracea L. Varamin cultivar) were sown in pots containing 40% field soil and 60% sand (10 seeds in each pots). To investigate the impact of PGPR isolates and filter cake on concentration of macronutrients (K, Ca, Mg, and P), micronutrients (Cu, Zn, and Fe) and leaves dry weight, Pseudomonas protogenes CHA0 (CHA0) as a reference strain, P. alloputida RUM14 (RUM14) which was collected from Iranian field soil and 3% by weight of fresh filter cake (F3%) were used. Spinach seedlings were inoculated for 14 days with 50 mL of bacteria strains suspension with optical density one (OD600=1). 3% by weight of filter cake were mixed to soil of pots before sowing the seeds. Metribuzin herbicide at three levels (0 (H0), 50 (H1) and 100 (H2) grams per hectare) were used. The effects of PGPR, filter cake and metribuzin herbicides and their interactions were also studied (CHA0 + F0 + H1, RUM14 + F0+ H1, CHA0 + F0 + H2, RUM14 + F0 + H2, B0 + F3% + H0, B0 + F3% + H1, B0 + F3% + H2, CHA0 + F3% + H1, RUM14 + F3% + H1, CHA0 + F3% + H2, RUM14 + F3% + H2). The experiment had a randomized complete block design with three replications. The treatments (3 metribuzin herbicide × 2 filter cake × 3 PGPR) were arranged in factorial combination. The statistical analysis was performed using Duncan’s multiple range test at 5% probability level.Results: Statistical analysis revealed that the application of PGPR (CHA0 and RUB14), filter cake, and their interaction increased tissue plant concentration of macronutrients, micronutrient and leaf dry weight of spinach plant. Statistically, the highest concentration of P, K, Ca, and Mg macronutrients (5583.30, 83000.00, 10886.70, 10766.60 mg kg-1 dry matter, respectively), Cu, Zn, and Fe micronutrients (22.73, 73.00, and 221.36 mg kg-1 dry matter, respectively) and dry weight of leaves (8.76 g) was observed in treatment of combination of PGPR and filter cake. The application of Metribuzin herbicide led to decline the concentration of macronutrients, micronutrient, and leaf dry weight of spinach plant. The decline increased with increasing herbicide concentration. The lowest concentration of P, K, Ca, and Mg macronutrients (3233.30, 48867.00, 6403.30, and 6283.30 mg kg-1 leaf dry weight, respectively), Cu, Zn, and Fe micronutrient (4.40, 19.50, and 132.66 mg kg-1, respectively), and leaf dry weight (2.83 g) was observed in B0+F0+H2 treatment (using just herbicide 100 g ha-1). However, the detrimental effect of herbicide on leaf dry weight and mineral nutrition of spinach plant were alleviated using the PGPR (CHA0 and RUB14) and filter cake (F3%) either alone or together (RUM14+F3%, CHA0+F3%). Statistically, the greatest alleviation of the detrimental effect of herbicide was observed in the treatment of RUM14+F3%.Conclusion: The results of this research showed that inoculation of spinach with Pseudomonas PGPR (P. protogenes CHA0, P. alloputida RUM14) with and without filter cake not only improved the growth and mineral nutrition of spinach plant, but also alleviated the detrimental effect of herbicide in the plant. In general, the proper function of PGPR and filter cake in spinach plant growth is due to 1- Supplying more nutrients to the spinach plant due to filter cake rich in nutrients 2- The ability of Pseudomonas bacteria to induce resistance of the plants to stress and supply of some nutrients such as iron due to its ability to produce siderophore 3- Supply of food by filter cake for further growth of PGPR and the possibility of increasing the population of these bacteria. 4- Filter cake rich in organic matter can improve the physical and biological properties of the soil and can provide the better conditions for plant growth and nutrition. The results of this research showed that P. alloputida RUM14 and filter cake can be used as biological and organic fertilizers.
N. Ghasem Jokar; habib nadian; B. Khalili Moghaddam; m. heidari; M.H. Gharineh
Abstract
Introduction: Drought stress is one of the main problems in agricultural productions in arid and semiarid regions such as Iran. Lack of water influences on most of plant physiological processes such as photosynthes, cellular development and uptake and transmission of nutrients in plants. Some approaches ...
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Introduction: Drought stress is one of the main problems in agricultural productions in arid and semiarid regions such as Iran. Lack of water influences on most of plant physiological processes such as photosynthes, cellular development and uptake and transmission of nutrients in plants. Some approaches such as selection of resistance cultivars to drought stress, and selection of dripped irrigation have been applied in order to increase the irrigation efficiency. In recent years, biological approaches such as mycorrhizal symbiosis have been used to alleviate the detrimental effects of drought stress. Mycorrhizal symbioses increase the absorption of nutrients, especially phosphorus, and reduce the adverse effects of environmental stresses. It can also improve the host plant growth and yield. The percentage of mycorrhizal dependency of host plants depends on different environmental factors (such as light intensity, temperature, soil conditions), as well as morphological and physiological characteristics of plants. 1n 2010, a greenhouse pot experiment was conducted at University of Agriculture and Natural Resources Ramin. The effect of mycorrhizal inoculation on root morphology of three leek genotypes and uptake of phosphorous, calcium and potassium in shoot and root were studied.
Materials and Methods: The experiment was conducted in a completely randomized design consisting of a 3×3×2 factorial combination. Experimental factors included three levels of soil moisture (40, 60 and 80% of available water in the soil), two mycorrhizal status (with and without fungus Glomus intraradices) and three leek genotypes including: Shadegan (with low root branching, short and thin root length), Esfahan (with abundant root branching and long root length) and Porrum (with low root branching, short and thick root length). The treatments were replicated four times. The soil was autoclaved at 121°C and15 PSI for 15 minutes and gently packed into PVC pots, 200 mm long and 150 mm in diameter. Leek seeds were sterilized with sodium hypochlorite (NaOCl) solution (10%) for 20 min. Two hundred grams of inoculum (spore, hyphae, mycorrhizal clover of root fragments and soil) were placed in deep of plant root. Each pot received 10 cm-3 nutrients solution, free of P weekly. Plants equally watered for one mounth then, drought stresses were applied. Leeks were harvested 12 weeks after planting. Sub-samples of roots were taken for determination of root length were cleared in 10% (w/v) KOH solution and then were stained with trypan blue and root colonization was studied using modified Phillips & Hayman. The colonized root length was determined by binocular and gridline intersect method of Tennant. Phosphorus concentrations were measured by the method of colorimetery with a spectrophotometer. Potassium and calcium concentrations were determined by flame photometer and titration with vercin (Ethylene diamine tetra acetic acid: EDTA), respectively. The statistical analysis was performed using MSTAT-C statistical software and means were compared by Duncan’s multiple range test at the significance level of P
