جستجوی مقالات مرتبط با کلیدواژه « Root colonization » در نشریات گروه « آب و خاک »

Quinoa (Chenopodium quinoaWilld.) is a high-yielding pseudo-cereal crop, belonging to the Chenopodiaceae plants, shows tolerance to salinity stress. As a chenopod plant, it could not establish a symbiosis relation with mycorrhizal fungi, but there are evidences that the Serendipitaindica (endophytic fungus) could enter the root and more likely improves the tolerance of quinoa against salt stress. This study was performed as a pot experiment in Completely Randomized Factorial Designs (CRFD) with three replications in a sterilized sandy loam soil. Experimental factors included two levels of S. indica (inoculated and non-inoculated) and salinity levels of 1.47 (initial electrical conductivity of soil), 5, 10, 20 and 30 dS/m. The interaction effect of salinity stress and fungal inoculation was significant for studied traits in both shoot and root (P <0.05), except for the concentrations of nitrogen and phosphorus in the root. The concentrations of phosphorus, potassium, calcium and magnesium, growth traits and percentage of root colonization in quinoa were significantly reduced by increasing salinity levels (P <0.05). S. indica increased root dry weight in control, 5 and 10 dS/m by 23.45, 25.66 and 25.57%, compared to no-fungal treatment, respectively. At initial electrical conductivity (1.47dS/m), shoot dry weight increased by 9% in inoculated plants compared to the non-inoculated treatment. Inoculation with S. indica reduced the concentration of root sodium at salinity levels of 10, 20 and 30 dS/m by 30.49, 66.78 and 43.55%, respectively, compared to the non-inoculated treatment. In the aerial part, the fungus could reduce the sodium concentration at 10, 20 and 30 dS/m by 20.96, 13.28 and 10.24%, respectively, compared to the treatment without the fungus. Based on the results, inoculation with the fungus significantly increased the concentrations of nitrogen, phosphorus and potassium in shoots at 20 and 30 dS/m.

Today, fungicides are widely used to prevent or eradicate a variety of pathogenic fungi, but in some cases their use has destructive effects on beneficial microorganisms such as mycorrhizal fungi. Mycorrhizal fungi are among the beneficial microorganisms used in the production of biofertilizers. After mycorrhizal symbiosis, plant features included water and nutrient uptake as well as plant resistance to biotic and abiotic stresses improve. These microorganisms are also used to control soil pathogens. The present study was conducted to investigate the effect of concomitant use of fungicides including benomyl, roralthias, mancozeb and Tilt on the effectiveness of R irregularis in both wheat and corn plants under greenhouse conditions. The experiments were designed as a completely randomized design with five treatments and four replications. The effect of fungicides on the growth characteristics of wheat (Chamran cultivar) and corn (Zeamays, Single Cross 704) and their symbiosis relationship with R. irregularis were investigated. The results showed that the effectiveness of mycorrhizal fungus application was not affected by the concomitant use of fungicides. The application of fungicides also improved some growth characteristics in wheat and corn, although in most cases the differences with the control treatment were not significant. In general, two milliliters per liter of Tilt for wheat and two grams per liter of benomyl for corn can be recommended when using R. irregularis inoculum at the same time

In order to evaluate the potential of native species of saffron arbuscular mycorrhizal fungus under the conditions of irrigation cut stress on its physiological traits, a study was conducted as split plot factorial based on a randomized completely design with three replications in the institute of Soil and Water research in Karaj, during the years 2017-2019. Treatment consisted: Irrigation regime as the main factor in three levels (such as optimal irrigation as control, water interruption at the beginning of the growing season (mild restriction water) and water interruption at the beginning and mid of the growing season (severe restriction water)), organic fertilizer in three levels (no organic fertilizer, vermicompost (20 ton ha-1) and biochar (10 ton ha-1) and Arbuscular mycorrhizal fungal in three levels (no application, isolate a and isolate b) as the subfactor. . Based on the molecular findings, both isolate isolated from saffron rhizosphere belonged to Rhizophagus irregularis. The results of this study showed that the interaction of irrigation regime, organic fertilizer and R. irregularis had a significant effect on all measured parameters. The highest percentage of root colonization (98.7%) was for optimal irrigation treatment with biochar and isolate b. The highest content of chlorophyll a, b and carotenoids (with an average of 5.74, 4.36 and 1.52 μg / ml, respectively) was observed in the optimal irrigation treatment with vermicompost and isolate b. Also, the treatment of severe water restriction with biochar and isolate b increased 253, 82, 95 and 165% of CAT, POD and SOD enzyme activities and proline, respectively, in comparison with the optimal irrigation treatment and no application of organic fertilizer and mycorrhiza fungal, which had the lowest amount of these traits. According to the results obtained from this study, it is argued that the use of biochar and vermicompost fertilizers with isolate b can reduce the destructive effects of soil moisture stress.

Drought is one of the most important environmental stresses that adversely affect the plant growth and crop production. Arbuscular mycorrhizae fungi help their host by absorption of water and mineral nutrition. In order to evaluate mycorrhizal fungus and water deficit stress on growth characteristics, chlorophyll content and root colonization percentage of almond (Prunus amygdalus) rootstock, a completely randomized design with factorial arrangement was conducted with three replications in agricultural and natural research center of Shahrekoard. The treatments consist of two levels of mycorrhizal fungus (with (M1) and without (M0) mycorrhizal fungus), four types of rootstock (bitter, local Shorab 2, GF and GN) and four levels of water deficit stresses (Control (I0), slight (I1), moderate (I2) and severe (I3)). The results revealed that the rootstock types had significant effects on studied parameters and the maximum measured parameters was observed in GF rootstock treatment. Water deficit stress also had significant effects on examined parameters. With increasing water deficit stress, root colonization percentage and root dry weight decreased significantly. Mycorrhizae fungi treatments increased root dry weight and root colonization percentage 27 and 40 percent respectively. The maximum stem length, stem diameter and plant dry weight were observed in GF +I1 treatment. The highest amount of root colonization percentage (74.5 %) was achieved in I1 + M1 treatment. Therefore, based on the results, the mycorrhizal fungus increased the growth properties of almond rootstock and reduced the harmful effects of water deficit stress.

Some beneficial soil microorganisms can reduce salt stress in many crops. Two experiments were carried outto study the effect of salinity and microorganisms on the growth characteristics of Plantago ovata Forsk. In the first experiment, tolerant species of phosphate-soluble bacteria screened in a salinity stress condition, a number of bacteria were subjected to semi-quantitative phosphate solubility test. The superior isolate was identified as Pseudomonas fluorescens based on the sequence 16S rRNA gene and other phylogenetic analysis. The second experiment was a factorial experiment in randomized complete block design with three replications. The first factor was three levels of salinity (2.5, 5 and 10 dS/m), the second factor was mycorrhizal fungus including Funneliformis mosseae, Rhizophagus intraradices and Glomus fasciculatum, and the third factor consisted of two levels of non-bacterial and bacterial application. Shoot and root dry weight, root to shoot dry weight ratio, mycorrhizal growth response and root colonization percentage were measured. Analysis of variance showed that interaction of salinity stress and mycorrhizal fungus on shoot dry weight was significant at level 1% probability. The interaction of salinity stress and bacteria on the ratio of root dry weight to shoot was significant at 5% probability level. The highest root dry weight and root/shoot ratio (1.7 and 0.9 respectively) were obtained at 2.5 dS/m + Glomus fasciculatum treatment. The highest mycorrhizal growth response percentage was 76.7% at 10 dS/m + Rhizophagus intraradice treatment.  Comparison of the mean interactions between salinity stress and bacteria showed that the highest mycorrhizal growth response percentage was obtained in the 10 dS/m salinity + Pseudomonas fluorescens treatment (45.6%). The results also showed that salinity decreased the yield of Isabgol, but the simultaneous application of PSB and AMF could compensate the negative effects of salinity stress. According to the results, it is possible to use the simultaneous application of Pseudomonas fluorescens and Rhizophagus intraradices to maximize the production of Plantago ovata Forsk.

This study was conducted to evaluate the effect of earthworms (Eisenia fetida) and arbuscular mycorrhiza fungi (F. mosseae) as well as their interactions on the root colonization, soil pH and soil dissolved organic carbon and nutrient concentration of iron, zinc, copper and manganese in maize. Experimental treatments included control, earthworm, mycorrhiza and earthworm + mycorrhiza was conducted in a completely randomized design in research greenhouse of Ferdowsi University of Mashhad with three replications. The results showed that the presence of earthworms in mycorrhiza + earthworm treatment had no significant effect on mycorrhizal root colonization compared with mycorrhiza treatment. The experimental treatments significantly reduced soil pH compared to the control treatment. Although experimental treatments significantly increased shoot dry weight, dissolved organic carbon and availability of iron, copper, zinc and manganese in the soil compared to control, however, it had a different effect on nutrient uptake by the plant. The highest concentration of Zn and Mn in shoot was obtained in mycorrhiza treatment that was statistically significant compared to other treatments (p

Introduction: Lead (Pb) is considered to be particularly toxic and responsible for significant decreases in biological activities in soils. Phytoremediation is an emerging and low-cost technology that utilizes plants to remove, transform, or stabilize contaminants located in water, sediments, or soils. The success of phytoremediation depends on the interactions between rhizosphere macro and microorganisms and plant roots. Among these organisms, the role of earthworms, mycorrhizal fungi, and plant growth promoters' rhizobacteria have been considered. In this study, we have evaluated and compared the combined effects of earthworms and bacteria on root colonization and plant growth in a contaminated soil. Material and method: Three plant species seeds (Zea mays (maize); Cynodon dactylon (bermudagrass) and Stachys inflata), after surface-sterilization and germination were transplanted into each plastic pot contained 4 kg of contaminated soil (collected from bama mining area located in the southwest of Isfahan) that already autoclaved at 121 oC for 2 h. A completely randomized design with 2×2×2 factorial treatment combination was used with the following factors: with or without earthworm treatments (Eisenia foetida), with or without arbuscular mycorrhizal (AM) fungal treatments and with or without rhizobacteria. After about three (bermudagrass and maize) and four (Stachys inflata) month growth in greenhouse condition, plant shoots were harvested. Pb and phosphorus (P) concentration, root colonization, spore abundance and root colonized length were determined.
Results and Discussion: In general, inoculation of these organisms differently affected root colonization, spore abundance, soil phosphorus (P) availability and plant growth, and showed variable results depending upon plant species and soil organisms involved. The significant and negative correlations between soil P availability and root colonization for all the plants (maize: r=-0.48, P<0.05; bermudagrass: r=-0.74, P Conclusion: This study showed that increasing the availability of soil P and Pb could be one of the decrease factors in root colonization, but the negative Pb effects depend on plant sensitivity. Furthermore, root colonization may not alone be a suitable index for plant growth and could be different with plant species and soil P or Pb concentrations. Furthermore, the relationship between plant growth and mycorrhizal symbiosis was higher in plant sensitive to Pb toxicity.

The activities of earthworms and mycorrhiza affect on water and nutrient uptake and crop yield. The aim of this study was to evaluate the effect of earthworm (Eisenia fetida) and arbuscular mycorrhiza fungi (AMF, Funneliformis mosseae) on root colonization, shoot dry weight, phosphorus and nitrogen uptake, organic carbon and soil microbial biomass C. In this regard, a greenhouse experiment was conducted in a completely randomized design (CRD) with three replications in Agricultural Research Station of Ferdowsi University of Mashhad. The experimental treatments consisted of control, single and integrated treatments of earthworm and mycorrhiza. The results showed that inoculated treatments with arbuscular mycorrhizal fungi significantly increased the amount of root colonization. The same trend was observed in combined treatments with mycorrhizal fungi and earthworm. The results also revealed that the integrated application of earthworm and mycorrhiza treatment increased the concentration of P and N in shoot by 105% and 79% ,respectively, compared to control treatment (p

water deficiency is one of the most limiting factors of agricultural production in arid and semiarid areas. In recent years beneficial microorganisms were evaluated as one of the techniquesto reduce the effects of drought stress and increase sustainable agricultural production. Therefore, this study was performed to evaluate the effect of mycorrhizal fungi on growth and uptake of some elements on lentil under drought stress conditions.
Experiment was performed as factorial test in a completely randomized design including two factors, drought stress at four levels (20%, 40%, 60%, and 80% PAW) and mycorrhizal fungi at four levels (Rhizophagus intraradices and Funneliformis mosseae, a mixture of two fungal species, and control), in growth chambers at Department of Soil Science and Engineering, Tehran University, 2014. After growth period, the effect of different treatments on growth traits such as number of nodules, shoot and root dry weights, number of sheaths, chlorophyll index, root colonization, plant height and content of elements of N, P, K, Fe, and Zn in the shoot were measured and recorded. Analysis of variance and mean comparison of data were performed with SAS software and Duncan’s test (pFindings: The results showed that all measured plant traits due to the effect of water stress decreased, so that dry matter of shoot, root dry weight, number of sheaths, leaf chlorophyll index, root colonization and plant height at the highest level of stress S1 than the control NS, respectively 49.99, 41.12, 11.2, 24.4, 26.06, 28.09 and 22.15 percent reduced. The interaction of water stress and mycorrhizal fungi on all measured traits except for plant height, root dry weight, chlorophyll index, zinc, phosphorus and potassium was significant (p Water stress had a negative impact on all indicators of growth, but the greatest reduction in root and shoot dry weight was seen. The use of mycorrhizal fungi had a significant effect on growth traits and nutrient uptake. The use of mycorrhizal fungi R. intraradices and F. mosseae reduced the negative effects of water stress and led to the increase of growth and more absorption of elements.
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Sulfur is the key element for higher crops and plays an important role in the formation of proteins, vitamins, and enzymes. It is a constituent of amino acids such as cysteine and methionine, which act for the synthesis of other compounds containing reduced sulfur, such as chlorophyll and utilization of phosphorus and otheressential nutrients.Deficiency of this nutrient in soil is usually compensated by using chemical fertilizers. However, these fertilizers have harmful effects on the environment and decrease the quality of the agriculture products. Therefore, biological fertilizers are more useful for using in agricultural ecosystems.Sulfurshould be addedto the soil, usually in a reduced form such as elemental sulfur. Use of S oxidizers enhances the rate of natural oxidation of S and speeds up the production of sulfates and makes them available to plants consequently resulting in an increased plant yield. The role of chemolithotrophic bacteria of the genus Thiobacillus through oxidation process in the soil is usually emphasized. Sulfur oxidation is the most important step of sulfur cycle, which improves soil fertility. The result is formation of sulfate, which can be used by the plants, while the acidity produced by oxidation helps to solubilize nutrients in alkaline soils. These bacteria can solubilise the soil minerals through the production of H2SO4 that reacts with these non-soluble minerals and oxidised them to be available nutrients to the cultivated plants. Arbuscular MycorrhizalFungi isan important component ofthe microbiota, mutualistic symbioticsoilfungithatcolonizesthe rootsofmost cropplants.The AM symbiosis involves an about 80% of land plant species and 92% of plant families. They have theability to enhance host uptake of relativelyimmobile nutrientsparticularly phosphorus (P) andzinc (Zn),Manganese (Mn) andiron(Fe).Arbuscular mycorrhizal fungi increased plant uptake of phosphorus, nitrogen and water absorption. Inoculation withthesefungihas increased the yield of numerous field-grown crops. This study was aimed to evaluate the effects of thiobacillus bacteria and sulfur application on soil pH, and also their interactions with mycorrhizal fungi in order to improve nutrients uptake and grain yield of maize under alkaline soil condition. Treatments arranged as factorial experiment were based on RCBD with three replications. Treatments consisted of mycorrhizal inoculation: inoculated (m1) and non-inoculated (m0), thiobacillus in two levels of inoculated (t1) and non-inoculated (t0) and three levels of sulfur (S0: 0 kg.ha-1, S1: 250 kg.ha-1 and S2: 500 kg.ha-1). Four-row plots were prepared with row width and intra-row space of 60 and 20 cm, respectively. Seeds of maize (Zea Mays, Sc:647) were surface sterilized in a 10% (v/v) solution of hydrogen peroxide for 10 min, were rinsed with sterile distilled water. Before sowing, 300 kg of urea per hectare were applied according to the results of soil analysis. In order to facilitate oxidation of sulfur to sulfate form,, S was applied and thoroughly mixed into top 30 cm of soil 30 days before sowing. One week before sowing, thiobacillus (Thiobacillus thiooxidans) was inoculated. Inoculum of AM fungus Glomus intraradices, were added to soil just before planting at about 2 centimeters below seed sowing dept. To measure Arbuscular Mycorrhizal colonization, root plants collected one week before harvesting, cleared in 10% KOH at 80˚C for 2 h, and then acidified in 1% HCL for 60 min. Then the cleared roots were stained in a solution of Trypan blue. For nutrient analysis, the following procedure was applied. Zn, Fe, S, and P were determined by Inductively Coupled Plasma-atomic emission spectrometry apparatus. For this purpose, ash of seed samples was prepared at 500-550 degree of Celsius and then 5 ml of HCl 37% was added and with dionized water to reach to 50 ml. Kjeldahl method was used to determine nitrogen. Analysis of variance was performed on all experimental data and means were compared using the least Significant Differences (LSD) test with SAS software. The significance level was p>0.05 unless stated otherwise. Results showed sulfur application increased significantly the amount of S, P, N, Fe, Zn, shoot dry weight and leaf chlorophyll of maize. With increasing Sulfur, sulfur concentration in plant shoot increased with linear trend. The highest S concentration was obtained with 200 mg.kg-1 S and the lowest amount was obtained from control plots. Applications of 50, 100, 150 and 200 mg.kg-1 S increased P content about 0.45, 3.91, 4.74 and 5.56 %, respectively. The highest N contentwas obtained with 100 mg.kg-1 S. The thiobacillus significantly increased P, Fe, Zn anddecreased root colonization and soil pH compared to control. Thiobacillus bacteria increased shoot P only with application of 100 mg.kg-1 S. Mycorrhizal inoculation increased the amount of N, P, S, Fe, Zn, shoot dry weight and root colonization. Inoculation with G.intra and G.mosseae increased shoot P content about 4.18 and 3.34% in comparison with the control plots. Single or combination of sulfur and thiobacillus had a negative impact on the root colonization. Based on the results it seems that sulfur, thiobacillus and mycorrhiza in alkaline soils improved crops nutrition and growth. S application and thiobacillus interaction on S concentration of maize shoot were significant. In condition of 0 or 50 mg.kg-1 S application, inoculation of thiobacillus is recommended. Also, the effects of mycorrhiza on P shoot was significant with no application of S.

The present study examined the effects of mycorrhizal fungus Glomus sp. on pistachio growth parameters and root-rot disease of pistachio seedlings under greenhouse conditions. The experiment was conducted in factorial arrangement based on completely randomized design with six replications. Examined factors included: levels of Glomus inoculation (with (M1) and without inoculation (M0) and two levels of Fusarium (inoculation with two isolates (F1) and F2) with a control (F0)). The results showed that Glomus sp and Fusarium isolates had a significant effect on all growth parameters (p< 0.01). There was significant interaction effect of treatment on shoot height, root dry weight, leaf area, root volume and root colonization (p< 0.01) and shoot fresh and dry weights (p< 0.05). Root rot disease was increased when pistachio seedlings were inoculated with F1 and F2 isolates of F. solani compared to control treatment (F0). The percentage of root colonization by F1 and F2 isolates was reduced (26.6% and 43.7% respectively) when pistachio seedlings were inoculated with Glomus sp. Based on the results, inoculation of pistachio seedling with Glomus sp. can reduce the root rot disease and improve plant growth parameters.

Mycorrhizal fungi may enhance plants growth and development by increasing the water use efficiency and nutrients uptake and alleviating of the salinity and drought stresses. This study was conducted to investigate the effects of three arbuscular mycorrhizal fungi species (Glomus intraradices, G. mosseae and G. versiforme) on growth and development parameters of marigold with four treatments (non inoculated or control plants and inoculated plants with three mentioned fungal species) and five replications in complete randomized design. Comparison of the mean values was done using Duncan’s Multiple Range Test at 5% probability level. Inoculated plants with all the three mycorrhizal fungi had better growth and development than control plants and symbiosis of hosted plants with mycorrhizal fungi resulted in significantly (p <0.05) increase of the plant height (upto 3 times), flower size (1.5-2.5 times), fresh and dry weights (more than 3 times), colonization rate, phosphorus concentration of root and earlier flowering (14-15 days) compared with non-inoculated plants. G. versiforme was more efficient than the other two mycorrhizal fungi regarding the mentioned traits. It seemed that the higher percentage of colonization with this species was the probable cause of its good efficiency.

Zinc deficiency is one of the most common micronutrients deficiencies in plants and reduces production. The purpose of this research was to use arbuscular mycorrhizal fungi and study its effect on Zn deficiency in corn and the plant ability to absorb zinc، phosphorus، and iron، and growth of corn plants. This experiment was performed in two parts. The first part was a factorial experiment conducted in completely-randomized design (CRD) with two factors zinc-deficient (-Zn) and zinc-sufficient (+Zn) (0 and 16 μM) and two fungi levels: +M and -M (mycorrhizal and non-mycorrhizal) cultured in perlite in plastic pots. Each treatment had four replicates. The second part of the experiment was conducted as completely-randomized design (CRD) with two levels of fungi (+M and -M) and four replicates cultured in perlite. The first results showed that in treatments with zinc deficiency، mycorrhizal plants had significantly less growth than non-mycorrhizal plants. Zinc deficiency caused a significant increase in the concentration and amount of phosphorus in shoot and root of mycorrhizal and non-mycorrhizal plants. Mycorrhizal plants with zinc deficiency had the highest concentration and amount of iron and non-mycorrhizal plants with sufficient zinc had the lowest concentration and amount of iron. Zinc deficiency increased the percentage of root colonization of mycorrhizal plants to 58%. In the second part of this study، it was observed that mycorrhizal inoculated plants were able to absorb zinc from the insoluble sources of zinc (such as ZnO).

In order to investigate variations of spore population, root colonization and also to determine mycorrhizal symbiosis in the root and rhizosphere of Pistachio trees (Pistacia vera) in natural forests, two study stations in Kalat (Chachaeh) and Sarakhs (Shorlogh) regions were selected. Sampling from soil and root of the trees were taken from under the canopy and from a depth of 30 cm. On a monthly basis. The roots were stained and the colonization rate and the variations of spore population were measured. Some soil characteristics including pH, moisture, organic material percentage and available phosphorus were determined, The correlation coefficients between the measured factors were calculated. The results indicated that vesicular – arbuscular mycorrhiza (VAM) was the only symbiotic mycorriza of pistachio trees. Average amounts of root colonization were 13% and 11% in Chahchaheh and Shorlogh stations, respectively. Also, average numbers of spores per 1 gram of dry soil in the above stations were 12 and 10, respectively. The correlation between the variation of spore population and colonization levels was positive but the correlation between spore population and soil moisture, organic material, available phosphorus and pH was negative.