Ghorbanpour M.,Arak University |
Hatami M.,Arak University |
Khavazi K.,Soil and Water Research Institute
Turkish Journal of Biology | Year: 2013
This study examined the effects of inoculation with 2 rhizobacteria strains, Pseudomonas putida (PP) and Pseudomonas fluorescens (PF), on growth parameters, chlorophyll, proline, leaf relative water content (RWC), antioxidant enzyme activities (including superoxide dismutase (SOD), peroxidase (POX), and catalase (CAT)), tropane alkaloids (such as hyoscyamine (HYO) and scopolamine (SCO)), and production of Hyoscyamus niger under 3 water deficit stress (WDS) levels, i.e. 30% (W1), 60% (W2), and 90% (W3) water depletion of field capacity. The results showed that inoculation with PP and PF strains minimized the deleterious effects of WDS on growth parameters. The activities of SOD and POX in root and leaf were increased to a significant extent with inoculation of PP and PF, and also with WDS treatment, whereas CAT activity decreased with increasing WDS, except for in plants treated with the PF strain. The maximum proline, HYO, and SCO content were recorded in PF-treated plants under W3 conditions. In contrast, the highest root and shoot alkaloids yield were obtained in plants bacterized with PP against W1 conditions. PP was the most effective strain under low WDS, PF had the highest efficiency in improving the growth and alkaloid production in the presence of severe (W3) WDS. Integrative use of effective plant growth promoting rhizobacteria (PGPR) and WDS could be an encouraging and eco-friendly strategy for increasing alkaloid yield and content in Hyoscyamus niger organs. © TÜBİTAK.
Rahmani H. Asadi H.A.,Soil and Water Research Institute |
Rasanen L.A.,University of Helsinki |
Afshari M.,Soil and Water Research Institute |
Lindstrom K.,University of Helsinki
Applied Soil Ecology | Year: 2011
The common bean (Phaseolus vulgaris L.) occupies more than 120,000. ha in Iran but information on the genetic structure and nitrogen fixation potential of the rhizobia nodulating this legume crop is scarce. Fifty-three bacterial isolates were sampled from root nodules of common bean cultivated in 12 different provinces of Iran. The genetic diversity of the isolates was analysed by PCR-RFLP of the 16S-23S rDNA internally transcribed spacer (ITS) region. At the similarity of 64%, common bean rhizobia were clustered into 10 groups, demonstrating a high degree of genetic variability among the isolates. Significant differences existed in the symbiotic potential of the isolates examined under greenhouse conditions. Ten isolates showed promising symbiotic characteristics in terms of shoot dry weight and symbiotic efficiency, and selected isolates revealed increased plant growth and yield under field conditions. © 2011 Elsevier B.V.
Yadegari M.,Islamic Azad University |
Rahmani H.A.,Soil and Water Research Institute
African Journal of Agricultural Research | Year: 2010
Growing evidence indicates that soil beneficial bacteria can positively affect symbiotic performance of rhizobia. The effect of co-inoculation with plant growth-promoting rhizobacteria (PGPR) and Rhizobium, on yield and yield components of common bean (Phaseolus vulgaris L.) cultivars was investigated in two consecutive years under field condition. PGPR strains Pseudomonas fluorescens P-93 and Azospirillum lipoferum S-21 as well as two highly effective Rhizobium strains were used in this study. Common bean seeds of three cultivars were inoculated with Rhizobium singly or in a combination with PGPR to evaluate their effect on growth characters. A significant variation of plant growth in response to inoculation with Rhizobium strains was observed. Treatment with PGPR significantly increased pod per plant, number of seeds per pod, weight of 100 seed, weight of seeds per plant, weight of pods per plant, total dry matter in R6 as well as seed yield and protein content. Co-inoculation with Rhizobium and PGPR demonstrated a significant increase in the yield and yield components. The results showed that all treatments of bacteria increased yield; however, strains Rb-133 with P. fluorescens P-93 gave the highest seed yield, number of pods per plant, weight of 100 seed, seed protein yield, number of seed per pod, and seed protein yield. © 2010 Academic Journals.
Khademi Z.,Soil and Water Research Institute |
Khademi Z.,University of Wales |
Jones D.L.,University of Wales |
Malakouti M.J.,University of Tehran |
Asadi F.,Soil and Water Research Institute
Plant and Soil | Year: 2010
Organic acids such as citrate and oxalate have been implicated in enhancing many rhizosphere processes including nutrient acquisition. This study was conducted to determine the importance of organic acid type and concentration on rhizosphere P mobilization and subsequent uptake by wheat (Triticum aestivum L.) roots and its translocation to shoots. A single wheat plant was grown in soil-filled rhizosphere microcosms and allowed to pass through a KH2PO433P-isotopically labeled patch of calcareous soil. Two days after 33P-injection, citrate and oxalate at concentrations of 1 mM and 10 mM were injected into the microcosms at the same patch every day over a period of 4 days. Oxalate resulted in a several-fold enhancement in plant 33P accumulation, while citrate had no such effect. In comparison with oxalate, high rates of citrate mineralization were observed suggesting that this reduced its potential to enhance plant 33P acquisition. This study concludes that organic acids cause an increase in P mobilization and P uptake by wheat but that this response is highly organic acid specific. © 2009 Springer Science+Business Media B.V.
Zabihi H.R.,Soil and Water Research Institute |
Savaghebi G.R.,University of Tehran |
Khavazi K.,Soil and Water Research Institute |
Ganjali A.,Ferdowsi University of Mashhad |
Miransari M.,Shahed University
Acta Physiologiae Plantarum | Year: 2011
We have recently indicated the plant growth promoting activities of Pseudomonas sp. as well as their alleviating effects on some soil stressors such as salinity. This is because in recent years, biological fertilizers have received special attention by scientists in sustainable agriculture. Accordingly, it is pertinent to specify the beneficiary level of such soil bacteria on plant growth including phosphorous (P) uptake. Hence, the objectives were to determine: (1) the plant growth promoting effects of the tested Pseudomonas sp., and (2) its combined effects with different P fertilization rates on the nutrient uptake (N, P, and K) and yield of wheat (Triticumaestivum L.) under greenhouse and field conditions. The experiments were factorially arranged on the basis of a completely randomized block design with three replicates and were conducted at the Research Farm of Agriculture and Natural Resources Research Center of Khorasan, Mashhad, Iran. P was fertilized at three levels including 0, 25 and 50 kg/ha P2O5. Pseudomonas sp. including Pseudomonasfluorescens 153, P. fluorescens 169, P. putida 4, and P. putida 108 were tested. Activities such as production of ACC deaminase and IAA-like products, as well as P solubilization were among the most important activities of the tested Pseudomonas sp. Such bacterial effects greatly enhanced wheat growth and yield under greenhouse and field conditions. The results also showed that the effects of Pseudomonas sp. on wheat nutrient uptake and the effects of bacteria as well as P fertilization on wheat yield were significant. P. putida 108 was the most effective strain enhancing wheat P uptake and grain yield under greenhouse (96 and 58%) and field (80 and 37%) conditions, respectively. Hence, although Pseudomonas sp. could be a suitable replacement for high P fertilization, however, the optimum wheat yield resulted when the bioinoculants are combined with 50% (25 kg/ha P2O5) P fertilization. This finding has great agricultural and environmental implications. © 2010 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków.
Siavoshi F.,University of Tehran |
Asgharzadeh A.,Soil and Water Research Institute |
Ghadiri H.,University of Tehran |
Massarrat S.,Tehran University of Medical Sciences |
And 2 more authors.
International Journal of Medical Microbiology | Year: 2011
The frequency of Helicobacter pylori vacA alleles, cagA, and jhp0947 and their association with types and advanced forms of gastritis in 143 first-degree relatives of gastric cancer (GC) patients was assessed. The subjects included 64/143 with antral-predominant gastritis, 68/143 with pangastritis, and 11/143 with corpus-predominant gastritis, with or without atrophy or intestinal metaplasia (IM). Further classification included the severity of atrophy or IM. Group I (40/143) included the subjects with moderate-marked atrophy or IM, group II (58/143) those with no atrophy or IM, and group III (45/143) with mild atrophy or IM. The frequency of vacA s1 was 79.7%, vacA s2 20.3%, m1 49.7%, m2 50.3%, cagA 76.2%, and jhp0947 58%. The most prevalent combination was vacAs1 cagA (+) (65.7%) (P= 0.001). Of the 143 subjects, 85 (59.4%) showed atrophy or IM, and 40/85 (47%) developed the moderate-marked atrophy or IM. No significant correlation was found between genotypes and the types of gastritis, non-atrophy, atrophy, or IM and severe forms of atrophy or IM (P> 0.05). It is proposed that H. pylori genotype status might not be considered as an important determinant of the types and advanced forms of gastritis in the first-degree relatives of GC patients. © 2011 Elsevier GmbH.
Zarea M.J.,Ilam University |
Hajinia S.,Ilam University |
Karimi N.,Ilam University |
Mohammadi Goltapeh E.,University of Tehran |
And 2 more authors.
Soil Biology and Biochemistry | Year: 2012
Salinity toxicity is a worldwide agricultural and eco-environmental problem. The intent of this study was to determine the salt tolerance of Piriformospora indica and strains of Azospirillum, isolated from non-saline and saline soil, as well as to determine their affect on the tolerance of wheat to soil salinity. In this study, an experiment was conducted to investigate the salt stress tolerance abilities of the endophytic fungi, P. indica, and Azospirillum strains, isolated from non-saline and saline soil, at five NaCl levels (0, 0.1, 0.2, 0.3, 0.4, 0.5 mol L -1). Additionally, a greenhouse experiment was conducted to test the effects of these selected microorganisms under increasing salinity levels on seedling growth, solute accumulation (proline and sugars), and photosynthetic pigments (Chl a, b, ab) of seedling wheat. Azospirillum strains were isolated in Iran from the root of field-grown maize from non-saline soil with an EC = 0.7 dS m -1 and from saline soil with an EC = 4.7 dS m -1. Plants were irrigated with non-saline water-tap water with an electrical conductivity water (ECw) value of 0.2 dS m -1, as well as low, moderate and severe saline water-irrigation with saline water with an ECw of 4 dS m -1, 8 dS m -1 and 12 dS m -1, respectively. The upper threshold of P. indica salinity tolerance was 0.4 mol L -1 NaCl in both liquid and solid broth medium. The upper thresholds of the salt adapted and non-adapted Azospirillum strains were 0.2 and 0.4 mol L -1 NaCl, respectively. The results indicated a positive influence of the organisms on salinity tolerance, more with the saline-adapted Azospirillum strains than the non-adapted strains. P. indica was more effective than the Azospirillum strains. These results could be related to a better water status, higher photosynthetic pigment contents and proline accumulation in wheat seedlings inoculated with P. indica. The benefits of both isolates and P. indica depended on two factors: water salinity and growth stage of the host plant. Inoculation with the two isolates increased salinity tolerance of wheat plants; the saline-adapted Azospirillum strains showed better performance with respect to improved fresh and dry weights at 80 and 100 days after sowing under both non-saline and saline conditions. When compared to plants inoculated with non-saline-adapted Azospirillum strains, those inoculated with adapted Azospirillum strains had much better performance with respect to the presence of photosynthetic pigment (Chl a, b and ab) and proline accumulation. Overall, these results indicate that the symbiotic association between P. indica fungus and wheat plants improved wheat growth, regardless of the salinity. It is concluded that the mechanisms for protecting plants from the detrimental effects of salinity by P. indica fungus and Azospirillum strains may differ in their salinity tolerance and influence the uptake of water, photosynthetic pigment contents and proline accumulation in wheat seedlings. © 2011 Elsevier Ltd.
Ordookhani K.,Islamic Azad University |
Khavazi K.,Soil and Water Research Institute |
Moezzi A.,Shahid Chamran University |
Rejali F.,Soil and Water Research Institute
African Journal of Agricultural Research | Year: 2010
In this study, the impact of inoculating tomato (Lycopersicon esculentum F1 Hybrid, GS -15) roots with plant growth-promoting rhizobacteria (PGPR) and Arbuscular Mycorrhiza Fungi (AMF) on fruit quality was evaluated. The control treatment was non-inoculated, the PGPR treatments were inoculated with Pseudomonas putida, Azotobacter chroococcum and Azosprillum lipoferum, and the AMF treatment was inoculated with mixture of Glomus intaradics + Glomus mossea + Glomus etunicatum. Compared to the control treatment, phytochemical factors, containing lycopene and antioxidant activity, shoot and fruit potassium increased by PGPR and AMF treatments. Maximum lycopene and antioxidant activity were found in plants of the Pseudomonas + Azotobacter + Azosprillum + AMF treatment. A positive correlation between lycopene with shoot potassium (r = 0.89, p<0.01) and fruit potassium (r = 0.86, p<0.01) was found. Minimum antioxidant activity was observed in plants of the Pseudomonas + Azotobacter treatment, but when AMF were added to this treatment, antioxidant activity increased significantly. In all treatments, shoot and fruit potassium increased when PGPR and AMF were used together. It was found that the application of Pseudomonas + Azotobacter + Azosprillum + AMF treatment had the most effect on lycopene, antioxidant activity and potassium contents on tomato. © 2010 Academic Journals.
Sabziparvar A.A.,Bu - Ali Sina University |
Mousavi R.,Bu - Ali Sina University |
Marofi S.,Bu - Ali Sina University |
Ebrahimipak N.A.,Soil and Water Research Institute |
Heidari M.,Bu - Ali Sina University
Water Resources Management | Year: 2013
The FAO56 Penman-Monteith (FAO56-PM) method is known as the standard method for estimating reference evapotranspiration (ET0) in a variety of climate types. Global solar radiation (Rs) is one of the essential inputs of this model, which is usually estimated from the Angstrom-Prescott (AP) method. The major drawback of the FAO56 pre-defined AP coefficients application is that the AP coefficients might need local calibration, to estimate ET0 accurately. The aim of this study is to compare the effect of the FAO56 pre-defined AP coefficients (i. e. a and b) and the locally calibrated ones, on estimating daily ET0 in 15 sites over Iran. Using long-term (1980-2007) experimental global solar radiation data (Rs), new locally calibrated (a) and (b) coefficients are suggested and new ET0 values are determined accordingly. It was found that the range of the calibrated AP coefficients (a, b) are climate dependent and locally different from those of recommended by the FAO56-PM method. Estimated ET0 at daily scale, improved up to 72. 7 % when the calibrated AP coefficients were applied instead of FAO56 pre-defined AP coefficients. Based on the results, applying the FAO56 pre-defined AP coefficients (i. e. a = 0. 25 and b = 0. 50) in northern subtropical-humid and southern hot climates caused larger ET0 errors. By contrast, the least ET0 errors were found in cool arid and cool semi-arid inland climates, locating about 1,330 above sea level. The correlations between the calibrated AP coefficients and geographical factors are also discussed in this research. © 2013 Springer Science+Business Media Dordrecht.
Soleimani R.,Soil and Water Research Institute
Journal of Plant Nutrition | Year: 2010
This research was carried out to determine the effects of rate and time of nitrogen (N) application on safflower in a calcareous soil. The nitrogen rates were 50, 75, 100, 125, and 150 kg ha -1 and three split application methods were used. Experimental treatments were conducted as a factorial in a randomized complete block design (RCBD) with three replications. Duncan's Multiple Range Test (DMRT) indicated that the three split application of 100 kg ha -1 of nitrogen in stages of sowing date, early stem elongation, and early flowering had higher grain yield (2627 kg ha -1) than other treatments. This result was forecasted by results of increases in number of heads per square meter (heads m -2), number of grains per head (grains/head), and thousand grain weight (TGW). The highest oil yield was 755 kg ha -1 with the 100 kg ha -1 nitrogen application and was 727 kg ha -1 in treatment of three split application. © Taylor & Francis Group.