نشریه روابط خاک و گیاه
پیاپی 26 (تابستان 1395)

The ability of hydrogels to absorb large amounts of water implies that they both provide less soil water losses by preventing deep percolation of water and also increase water use efficiency of plants leading to decrease the effects of water deficiency due to salinity stress on crops. To study the effect of two types of superabsorbent (Stockosorb and Xanous) on growth of greenhouse cucumber under saline-soil conditions, a factorial experiment based on completely randomized design with 12 replications was carried out in Research Greenhouse of Yazd University. At the first stage of the experiment, effect of applying superabsorbent polymers (Stockosorb and Xanous) at three levels (0, 3 and 6 g/kg dry soil) was investigated 25 days after planting by measuring different characteristics including number of leaves, plant height, leaf length and leaf width. At the second stage, the abovementioned characteristics, along with the number of flowers and fresh and dry weight of plants, were measured 35 days after planting. Results indicated that at both stages, adding Stockosorb to the saline soil (EC= 5 dS/m) significantly increased all measured parameters when compared to the control. Application of two levels of Xanous hydrogel to the saline soil had no significant effect on measured traits, except on number of flowers, as compared to the control. Variations of number of flowers in both hydrogel treatments, and at both application levels, showed that using superabsorbent could be important in enhancing the crop yield under difficult saline conditions.

Microbial endophytes, which are considered as the most important soil microorganisms, increase the yield of their host plants by creating changes in their genetic, physiological and ecological traits. Pirifomospora indica fungus is a member of Sebacinales order, which increases plant biomass and resistance to living and non-living stresses. In this study, effect of different concentrations [0 (control), 80, 160, 250 and 330 spores/ml) of endophytic fungus P. indica on plant height, chlorophyll indicator and branching of strawberry, under hydroponic culture, was examined in a completely randomized design with 28 replications. P. indica was inoculated by injecting around roots of strawberry plants. Two months after fungal inoculation, plant height and chlorophyll content was measured by using coulisse and SPAD, respectively. Results showed that maximum chlorophyll content, branching and plant height belongs to 330 spores/ml treatment with 15%, 30% and 24.5% increase as compared to control, respectively. Also, there was no significant difference among 80, 160 and 250 spores/ml treatments, while 330 spores/ml treatment was significantly different from other treatments (P≤ 0.01). Therefore, it can be concluded that high concentrations of fungus P. indica can affect the abovementioned traits and thus could have a positive effect on strawberry plant's growth and yield.

In order to compare the effect of mycorrhizal fungi, phosphate biofertilizer and manure application on growth parameters and dry weight of coriander medicinal plant, a factorial pot-experiment, based on randomized complete design with three replications, was carried out in 2012, in Faculty of Agricultural Sciences, University of Guilan, Iran. The factors were mycorrhizal inoculation Glomus mosseae (inoculated and non- inoculated), phosphate biofertilizer (0, 35 and 70 kg/ha) and cattle manure (0, 10 and 20 ton/ha). Results indicated that mycorrhizal inoculation and phosphate biofertilizer had significant effect on all evaluated traits. Maximum dry weight of plants, stem diameter, number of branches per plant, plant height, length of roots, dry weight of roots, and total chlorophyll and carotenoid content of leaves were found to be 24, 200, 23, 50, 13, 33, 36 and 58 percent, respectively, higher than the application of 20 ton/ha of manure. But, the highest number of umbrellas per plant was obtained by applying 70 kg/ha biofertilizer, which was 4% more than the application of 20 ton/ha manure. Based on the results, biofertilizers (mycorrhizal inoculation and phosphate biofertilizer) provide more favorable conditions, compared to the manure, in increasing the yield of coriander plant, for sustainable agriculture under greenhouse culture.

Considering the increase of using vermicompost fertilizers in greenhouse cultivation, effect of vermicompost application on growth characteristics of tomato and one of its major pests [greenhouse whitefly, Trialeurodes vaporariorum (Hem:Aleyrodidae)] was investigated. The experiment consisted of five treatments: control (without vermicompost), 30% and 60% solid vermicompost fertilizer, and 40% and 20% aqueous extracts of vermicompost. Effect of vermicompost on greenhouse whitefly was tested for two different cases of with-choice and no-choice. Results showed that significant increase in shoot dry weight and root dry weight of tomato in vermicompost treatments. The highest increase (18 and 12 fold, respectively) was observed in plants treated with 60% solid vermicompost. The highest amount of nitrogen (0.43 mg/kg), potassium (14.56 mg/kg) and phenol (1130.46 ppm) was recorded in60% solid vermicompost treatment. Also, application of vermicompost reduced the percentage of infested leaves to whitefly, such that the lowest amounts were 6.67% and 8.97% in 60% and 30% solid vermicompost treatments, respectively, and 10.53% in 40% aqueous extract of vermicompost. The mortality of the second instar nymph of greenhouse whitefly-the stage that insects become fixed to the leaves by their sucking mouthparts- was increased (about 10%) by application of vermicompost.

A greenhouse experiment was conducted to study the effect of zinc rates, arbuscular mycorrhiza and organic matter, on corn growth and micronutrients-uptake in a calcareous soil. Experimental design was factorial based on complete randomized design with 3 replications. Treatments consisted of 3 levels of Zn (0, 5 and 10 mg Zn/kg), 2 types of organic manure (sheep manure and municipal waste compost, each at 0 or 1% w/w) and 2 levels of mycorrhiza (no inoculation and inoculation with Glomus intraradices). Plants were harvested 8 weeks after emergence and used for chemical analysis. Roots were used to determine the degree of colonization. Results showed that application of Zn increased plant dry matter weight, total Zn and Cu uptake, root mycorrhizal colonization and decreased total Fe and Mn uptake. Arbuscular mycorrhiza increased plant dry matter weight, root mycorrhizal colonization and total Zn, Fe, Mn and Cu uptake. Application of both organic manures increased plant dry matter weight, root mycorrhizal colonization and total Zn, Fe, Mn and Cu uptake.

This research was conducted in order to evaluate the direct effects of organic and biofertilizers on yield of two native wheat cultivars (Bolani and cross-Bolani) in Sistan area. The experiment was performed as a factorial, based on a completely randomized design with three replications, in Research Greenhouse of University of Zabol. In this study, fertilizer factor at 8 levels [Vermicompost (F1), vermicompost compost (F2), vermicompost mycorrhiza (F3), vermicompost mycorrhiza compost (F4), compost (F5), compost mycorrhiza (F6), mycorrhiza (F7) and control (no fertilizer application, F8)] and two wheat cultivars [Bolani (C1) and cross-Bolani (C2)] were considered. Results showed that the highest grain yield (1.13 g/pot) was obtained from combination of mycorrhiza and cross-Bolani treatments (F7C2). Combined treatments of compost mycorrhiza and cross-Bolani (F6C2) and vermicompost compost and cross-Bolani (F2C2) were more suitable for nitrogen uptake. The highest percentage of protein (10.27%) was resulted from F6C2 and F2C2 treatment. Overall, combined treatments of F6C2 and F2C2 seem appropriate for Bolani and cross-Bolani wheat cultivars.

This study was conducted to assess the effects of zinc oxides (nano and ordinary) and Glomus intraradices fungi on yield concentration of micronutrients in green bean plant, by employing a factorial, completely randomized design, and three replications, under greenhouse conditions. The experimental factors included two levels of Glomus intraradices (with and without inoculation), two types of zinc oxide (nano and ordinary( and four levels of zinc oxide (0, 50, 100 and 200 mg/kg(. Results showed that 100 mg/kg nano zinc-oxide treatment with Glomus intraradices had significant effects on growth and yield of green bean. Concentration of Zn, Cu and Fe in plant, dry weight of roots and shoots per pot, length of roots and shoots per pot, and 100-seed weight were increased. Nano zinc-oxide treatments enhanced all measured parameters more than ordinary zinc-oxide treatments. Also, Glomus intraradices had positive significant effects on Zn, Cu and Fe concentrations in green bean plant.

Aloe vera is one of the medicinal plants, resistant to drought and high temperatures, that its gel has many applications in pharmaceutical, health and food industry. This experiment was conducted to determine the effects of salinity stress, caused by sodium chloride (NaCl) and calcium chloride (CaCl2), on leaf weight, gel content and ratio of some nutrients in Aloe vera, in Research Greenhouse of Shahrekord University, in 2012. This experiment was based on a randomized complete blocks design with 16 treatments and three replications. Treatments included four levels of NaCl concentration (0 (control), 30, 60 and 90 mM), three levels of CaCl2 (5, 10, 20 mM) and combinations of the two salts Based on the results, effect of salinity on wet and dry weight of leaf and gel, percentage of sodium, calcium, magnesium, potassium, and K/Na and Ca/Na ratio was significant. Increasing the concentration of NaCL, CaCl2 or their combination, reduced the percentage of magnesium, calcium, potassium, wet and dry weight of gel content and leaf yield. Results of this study showed that Aloe vera is not much tolerant to salt stress and its cultivation is not recommended in soils with EC value of more than 7 dS/m. Overall, under similar EC, the toxicity of NaCl is more than CaCl2 and attention to potassium and calcium nutrition is important under salinity stress.

In order to study the effects of superabsorbent polymers and drought stress on some morphological characteristics of Rosmarinus officinalis, a pot experiment was conducted as factorial, based on completely randomized design with four replications, in which factors included four levels of drought stress (irrigation up to 100, 75, 50 and 25 percent of field capacity (FC) level, respectively) and two levels of superabsorbent (without superabsorbent, and with one g superabsorbent per kg) in the Research Greenhouse of Islamic Azad University, Saveh Branch. The investigated traits were plant height, number of primary branches, fresh and dry weights of aerial parts, roots and whole plant, and also dry weight of leaves and stem. Results of this study showed that interaction effect of these two factors was significant on all of the examined characteristics, except plant height, dry weight of leaves and ratio of leaf to stem dry weight. The highest number of primary branches (9.55 branches/plant), fresh root weight (17.7 g/plant), dry root weight (10 g/plant) and total dry weight of the plant (33.75 g) was observed in 100% FC treatment with superabsorbent application. Also, the highest dry weight of leaves (12.3 g/plant), dry weight of stem (13.3 g/plant), fresh weight of shoots (58.3 g/plant), dry weight of shoots (23.8 g/plant) and whole-plant fresh weight (71.7 g/plant) were obtained in 100% FC treatment and without superabsorbent. Based on the results of this study, irrigation of rosemary at the field capacity level improves most of its morphological characteristics.

Aloe vera is one of the most popular ornamental plants that is widely used in production of medicines and cosmetics. To investigate the effect of different ratios of peat and perlite on quantitative and qualitative characteristics of Aloe vera, a split-plot experiment, arranged as completely randomized design, with five substrates (peat, peat and perlite (1:3 v/v), peat and perlite (1:1 v/v), peat and perlite (3:1 v/v) and perlite, (main plots)) at five different times (sub-plots) was conducted. Results showed that adding perlite to peat substrate increased the growth rate and quantitative and qualitative indices of A. vera. Maximum amount of antioxidants, total phenols, aloin and dry weight of plants were observed in peat and perlite substrate (3:1 v/v). But, maximum number of leaves, plant height, number of shoots, root weight, leaf weight, total weight, gel weight and dry weight of leaves were observed in plants grown in peat and perlite substrate (1:1 v/v). Based on these results, the peat and perlite substrate (1:1 and 3:1 v/v) could be recommended to increase quantitative and qualitative indices of Aloe vera.

Using bacteria for producing plant nutrients, applying proper methods of soil fertility, and nutrition of plants, other than preserving environment and human health, eliminates unnecessary and wasteful use of chemical fertilizers. Thus, in order to achieve this aim, a greenhouse experiment was carried out, based on completely randomized design with three replications, in Damavand city, during 2012, using phosphate-dissolving and nitrogen-fixing bacteria. Treatments were super nitro plus (4 lit/ha), bio super phosphate (2 lit/ha), super nitro plus (4 lit/ha) bio super phosphate (2lit/ha) simultaneously, and control (no fertilizer). The necessary amount of each fertilizer per pot was calculated and applied. The measured traits consisted of plant height, fresh and dry weight of roots, leaves and stem, root length, stem diameter, number of leaves, leaf area, and concentration of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids. Analysis of variance of data showed that most of the studied traits were affected by super nitro plus and bio super phosphate fertilizers. Results indicated that the experimental treatments significantly increased fresh and dry weight of shoot, chlorophyll a, chlorophyll b and total chlorophyll content as compared to control treatment.

The aim of this study was to evaluate the effects of mycorrhizal inoculation and phosphorus (P) application on arsenic (As) toxicity and absorption by fenugreek, after application of As to soil. In this greenhouse experiment, plants inoculated with three mycorrhizal species and grown in soils with different levels of applied P and As, were compared. Phytotoxicity of As was determined by studying plant growth, As accumulation, as well as uptake of macronutrients and concentration of photosynthetic pigments. Based on the results, addition of As significantly reduced plant growth, uptake of macronutrients and concentration of photosynthetic pigments. Most of the absorbed As was retained in roots and fenugreek roots had higher concentration of As than the shoots. In addition, P and mycorrhiza had a significant impact on all traits, except sodium concentration. In this study, the interaction between As vs. P as well as between As vs. mycorrhiza was significant on concentration of carotenoids, potassium and arsenic in shoots. P and mycorrhiza had a moderating role and decreased the negative effects of arsenic toxicity on these properties. Results of this experiment revealed that application of P fertilizer and mycorrhizal inoculation in fenugreek could be effective in reducing the negative effects of As stress by increasing the uptake of nutrients and concentration of photosynthetic pigments.

This experiment was carried out to study the effect of plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) on essential oil content, yield and composition of shoots in peppermint (Mentha piperita L.), based on completely randomized design with three replications, in the Research Greenhouse of Faculty of Agriculture, Urmia University, in 2010. Inoculation with three species of PGPR (Azotobacter, Bacillus and Pseudomonas) and three species of AMF (Glomus mosseae, Glomus intraradices and Glomus fasciculatum) and control (no bacterial or mycorrhizal inoculation) were the experimental treatments. Results revealed that the highest essential oil content (2.77%) and yield (0.259 ml per pot) was obtained in Glomus fasciculatum and Pseudomonas treatment, respectively. Chemical analysis of the essential oil showed that in all the treatments, the main components of the oil were menthol, menthone, isomenthone, 1,8- cineole, pulegone and menthofuran. The highest values of menthol (42.27%), menthone (19.33%), isomenthone (16.77%), 1,8- cineole (10.16%), pulegone (7.34%) and menthofuran (6.61%) were obtained in control, Glomus mosseae, Bacillus, Azotobacter, Glomus intraradices and Pseudomonas, respectively. Comparison of terpenoids content indicated that the amount of oxygenate monoterpene increased with application of Glomus mosseae, Glomus fasciculatum, Bacillus and Pseudomonas and hydrocarbonate monoterpene with Glomus fasciculatum, Glomus intraradices and Azotobacter. Total amount of monoterpene and hydrocarbonate sesquiterpene increased in all the treatments. In general, the results showed that different bacterial and fungal treatments have different effects on chemical composition of the essential oil of peppermint. Therefore, to achieve the needs of different industries for specific chemical profile of peppermint essential oil, it can be suggested that this plant be inoculated with bacterial and fungal treatments to get the desired chemical components.

In order to investigate the interaction of cadmium (Cd) and different levels of organic and inorganic nitrogen (N) on some physiological and morphological traits of purslane (Portulaca oleraceae) medicinal plant, an experiment was conducted in Research Greenhouse of Shahrekord University, in 2012. Nitrogen treatments were consisted of four separate application levels (60 and 120 mg N/kg soil in the form of urea and cattle manure), three levels of combined-fertilizer application (90 mg N/kg as ratios of 2:1, 1:1 and 1:2 from urea and cattle manure, respectively), and control (no fertilizer and manure) as the first factor and two levels of Cd (10 mg Cd per kg soil and no Cd application) as the second factor. Results showed that Cd significantly decreased leaf chlorophyll, leaf carotenoids, plant height, number of leaves, leaf dry weight, stem dry weight and shoot dry weight. However, increasing N application significantly increased the aforementioned traits under Cd and without Cd application. The greatest purslane yield was obtained in 120 mg N/ kg as cattle manure. On the other hand, there was no significant difference between 120 mg N/kg as urea and combined treatment (1:1) as cattle manure and chemical fertilizer. In general, it can be concluded that application of animal manure not only would increase potential yield of purslane, but also mitigates the Cd stress effect on growth of purslane crop.

To evaluate the effect of arbuscular mycorrhizal (AM) fungi (Glomus mosseae and Glomus intraradices) and Mesorhizobium Ciceri bacteria at three soil moisture levels [28% (field capacity, FC), 15% (-5 bar suction) and 9% (-10 bar tension) by weight] on morphological properties of root and aerial parts of chickpea, a greenhouse factorial experiment, arranged as a complete randomized design, was conducted in a sterilized soil. Results showed that moisture treatment had significance effect on number of pods, number of seeds, fresh and dry weight of root and aerial parts, plant height and root length and volume. Application of Mesorhizobium was effective on number of nodes, number of pods, number of seeds, fresh and dry weight of root and aerial parts, plant height, root length and volume. Glomus mosseae had significant effect on plant height. Interaction of moisture and AM fungi was significant on fresh and dry weight of root and aerial parts. Interaction effect of Mesorhizobium and soil moisture was only significant on number of nodes. In general, the highest fresh and dry weight of aerial parts (44.6 and 10.53 grams, respectively) was obtained by inoculation of chickpea by rhizobium bacteria and Glomus mosseae at FC moisture level, and AM fungi Glomus mosseae was more efficient compared to Glomus intraradices in both drought stress and without stress conditions.