جستجوی مقالات مرتبط با کلیدواژه « تریکودرما » در نشریات گروه « زراعت »

Seed germination and emergence are the most sensitive stages of growth and development of rice plants. In this regard, the use of growth-promoting fungi in the form of seed biological pretreatment (bio-priming) for germination and optimal growth of seedlings can be feasible. Therefore, this study aimed to investigate the effect of isolated root symbiotic fungi on the improvement of germination and growth components of two traditional and bred rice (Oryza sativa L.) cultivars.

This experiment was done as a factorial-based completely randomized design with three replicates at Sari Agricultural Sciences and Natural Resources University in the summer of 2021. Experimental treatments included 22 isolates of root symbiotic fungi (isolated and identified from previous experiments) and control (without inoculation) and two native (Hashemi) and bred (Roshan) rice cultivars. After the end of the germination period, the number of normal seedlings was counted and five normal seedlings were randomly selected to measure the length of the root, stem, and seedling as well as the fresh and dry weight of the root, stem, and seedling.

Based on the results of cluster analysis the fungi were divided into four and three groups in Roshan and Hashemi cultivars, respectively. In both cultivars, group I was selected as the best group. In this group, the highest positive effect on vegetative traits varied from 5 to 59% compared to the control in fungal treatments was related to Bjerkandera adusta (ST1), Trichoderma atroviride (SF1), Monosporascus cannonballus (B3) and Trichoderma atroviride (SN1) in Roshan cultivar and Bjerkand adusta (ST1) in Hashemi cultivar. The best fungal treatments in germination traits of Roshan and Hashemi cultivars were Chaetomium globosum (SE2) and Bjerkandera adusta (ST1), respectively.

Overall, the results indicated the positive effect of most symbiotic fungi on the growth and germination characteristics of rice in both Roshan and Hashemi cultivars. These results show that symbiotic fungi use different mechanisms to increase growth and improve germination indicators in plants.

Highlights:

1- Growth-promoting fungi in the form of seed biological pretreatment were used (bio-priming) for optimal growth and germination and of rice seedlings.
2- The effect of native fungi isolated was investigated for the first time in two native (Hashemi) and bred (Roshan) rice cultivars.

Salinity is one of the most harmful factors in the arid and semi-arid regions in the world that influences crop production. Micro-organisms can play an important role in adaptation strategies of plants to stress and by producing of plant growth promotion hormones such as cytokinin, gibberellic acid, auxin, amino acids, and vitamins of B groups help to more growth of the plant and have an important role in increasing of tolerant in plants in unsuitable environments.

This experiment was established as factorial in a completely randomized design with three replicates at Shahed University of Tehran. The treatments included salinity in four levels (0, 40, 80, and 120 mM NaCl) and biological pre-treatment at eight levels (control: non-inoculation), inoculation with Trichoderma harzianum fungus strain BI, with inoculation with azotobacter bio-fertilizer, inoculation with phosphate bio-fertilizer, inoculation with both bio-fertilizer, a combination of fungus and azotobacter bio-fertilizer, a combination of fungus and phosphate bio-fertilizer, inoculation with fungus and both bio-fertilizer). In this experiment, germination indices, photosynthetic pigments, proline, sodium, and potassium amount, starch, carbohydrate, electrical conductivity, and soluble protein were studied.

The result showed that the interaction effect of biological pre-treatment and salinity was significant on all indices except chlorophyll b and anthocyanin. Treatment of phosphate bio-fertilizer had maximum positive effect on germination percent with increasing salinity. In the co-application of fungus and azotobacter bio-fertilizer treatment, the amounts of chlorophyll a, b, and total chlorophyll in different levels of salinity were more than the other treatments and were incremental with further increasing of salinity level. The highest amount of potassium (4.10 mg/g FW) obtained in the co-application of a fungus with azotobacter bio-fertilizer under 40 mM of salinity and showed 22.02 percent increase in comparison to control. With rising salinity, fungus treatments were the most effective in preventing more increasing sodium amount and azotobacter bio-fertilizer in preventing more reducing potassium. The number of soluble proteins was the highest amount (13.09 mg/g FW) in the co-application of fungus and both bio-fertilizer and showed 38% increase compared to control at the same level of salinity.

The uses of microorganisms reduced the negative effect of salinity and led to the increase of potassium in shoots. Also, utilization of microorganism led to lower electrical conductivity at the highest salinity level compared to control and thus, positively affected germination.

Agricultural soils in many parts of the world are slightly to moderately are contaminated by heavy metals elements. Among them, Pb has an effect on growth and metabolism of plants with a wide range of adverse effects like decrease in root elongation and biomass, accelerated leaf senescence, inhibition of chlorophyll biosynthesis and seed germination, interferes with nutrient uptake, influence the net photosynthetic rate and respiration and alternate permeability of cell membrane. So, the usage of a fast and safe method is necessary to remove pollutants with the lowest cost and impact on the environment. One of the best methods is phytoremediation that the Brassicaceae family plants such as canola (Brassica napus L.) have a special ability to refine contaminated soils due to their much biomass production. On the other hand, bioremediation is one of the methods that has been considered in recent years to remove contaminants. In this context, it is important to use a variety of microorganisms like algae, fungi and bacteria in order to improve phytoremediation efficiency. Therefore, the purpose of this research was to evaluate the effect of Piriformospora indica and Trichoderma longibrachiatum on improving the growth and some physiological traits of canola under lead stress.

This research was done as factorial layout based on a completely randomized design with three replications. Treatments were four levels of lead from lead nitrate source (0. 500, 1000 and 1500 mg kg-1 of soil) and three treatments of fungi (control, Piriformospora indica and Trichoderma longibrachiatum). After 60 days of (Hyola 401 cultivar) planting time, coinciding with the end of vegetative growth and before flowering, Vegetative and some physiological traits were measured. To quantify the effect of lead stress regression analysis and linear and segmental models were used.

The results showed that node and leaf number, stem diameter, leaf fresh weight and stem dry weight (between 20 and 58%) were reduced as linearly and segmental model where lead levels increased from zero to 1500 mg. Also, inoculation of Piriformospora and Trichoderma fungi increased stem diameter and dry weight. Using the mentioned fungi had a positive effect on vegetative traits at different levels of lead. Accordingly, plant height, leaf area, stem and shoot fresh weight and leaf and shoot dry weight reduced from 27, 74, 68, 65, 69 and 70% in control to 12, 44, 35, 36, 52 and 52% in symbiosis with Piriformospora and 31, 48, 58, 53, 52 and 53% after applying Trichoderma at in 1500 mg as compared to the zero levels, as well. Also, the electrolyte leakage rate showed an increasing trend with 0.000084 slope Up to 500 mg and then with a 0.0018 slope. But plant inoculation with Piriformospora and Trichoderma reduced the electrolyte leakage with about two percent. In addition, the interaction between lead and fungi was significant on SPAD reading, chlorophyll a+b, relative water content (RWC) of leaves and proline. SPAD reading and chlorophyll a+b declined from nearly 18 and 35% in non-inoculation treatment to about 7 and 27% in Piriformospora, and 13 and 5% in Trichoderma in 1500 mg as compared to the control, respectively. Among morphological and physiological traits, the highest correlation (r=0.80; P<0.01) was between leaf area and RWC.

In conclusion, results indicated that vegetative traits showed more sensitivity to lead toxicity. Among these traits, the highest sensitivity was recorded in stem and shoot dry weights. Inoculation of canola seed with Piriformospora and Trichoderma fungi ameliorated this sensitivity in some traits. Accordingly, it seems that these fungi can improve slightly the adverse effect of lead toxicity and increase canola tolerance to lead stress.

The current study been conducted to achieveto effective antagonists for diseases control of seedling damping-off greenhouse pepper, casead by Rhizoctonia solani. Experiments has conducted based on completely randomized design in the faculty of agriculture and natural resources of Lorestan University in 2016-17. First, the fungi and biological agents were isolated and identified of the rhizosphere of Solanaceae plants. The antagonistic ability of fungal and bacterial isolates, such as Trichoderma harzianum and Trichoderma virens fungi and Bacillus subtilis bacteria, against R. solani was studied by using dual culture method. As well as antagonistic ability of fungal and bacterial agents and Trichomix HV biological fungicide were study in a greenhouse condition. The results showed that both species of T. harzianum and T. virens the prevented growth of fungi 9.45 and 15.59 percent respectively by colonization and sporulation in PDA. Antagonistic bacterial also caused effects such as outpour of the contents of hyphae, color change at the tip of hyphae, thinning and reduction of mycelium up to 8.47 percent. Also, results in greenhouse condition showed that B. subtilis and T. harzianum treatments have the most positive effects on growth traits such as height and weight (wet and dry) of the root and stem and reduced the severity of the disease up to 60.33 and 70.33 respectively; therefore they are the best antagonistic agents to control R. solani on pepper.

In this study, the antagonistic activities of eleven isolates belonging to 10 species of Trichoderma fungi including Trichoderma harzianum, T. atroviride (two isolates), T. viride, T. orientalis, T. citrinoviride, T. asperellum, T. spirale, T. crassum, T. pseudokoningi and T. ceramicum against rhizoctonia solani AG2-2, the causal agent of sugar beet root rot, were evaluated in a completely randomized design with four replications. Results showed that all Trichoderma isolates reduced the growth of pathogen significantly and the highest antagonistic effects were observed in dual culturing test in T. harzianum Z1 isolate, which caused 76.57% inhibition of pathogen mycelial growth. In greenhouse experiments, the efficacy of four selected Trichoderma isolates on sugar beet root rot control in Shirin cultivar was evaluated. Results showed that T. harzianum Z1, T. atroviride Z2, and T. orientalis Z4 caused 71.1, 66.6, and 58.3% decrease in root rot severity, respectively. In field experiments (2013-14) conducted in Hamedan Agricultural and Natural Resources Research Center, the effect of selected Trichoderma isolates in comparison with fungal treatment (carboxin-thiram) and control treatment on the occurrence and severity of root rot was evaluated through artificial contamination by Rhizoctonia solani. Results showed that selected Trichoderma isolates were significantly different in terms of disease control and T. harzianum Z1 isolate caused 66.4% reduction in the incidence of infection and 56% reduction in root rot severity compared with control. Therefore, this isolate is considered as the most effective antagonist in decreasing of Rhizoctonia root rot disease of sugar beet root.

IntroductionAccumulation of heavy metals in agricultural soils can be a threat to crop production due to plant toxicity. In the recent years, hyperaccumulator plants are cultivated to cleaning up the soils which contaminated with pollutants especially heavy metals. However, the biomass of these plants is low and metal specific. Many studies have shown that microorganisms can be used to significantly reduce the toxicity of heavy metals. Therefore, the present study aimed to determine the role of Trichoderma atroviride on the growth characteristics of tow cultivars of rapeseed in different levels on copper.
Materials and MethodsIn this study, a pot experiment was conducted in factorial arrangement based completely randomized design with three replicates. Treatment were T. atroviride fungi at two levels of inoculated and non-inoculated plants, four levels of copper nitrate including 0, 50, 100 and 150 mg l-1 and two cultivars of rapeseed consist of Hayola 401 and Sarigol. Trichoderma atroviride was prepared from Mycology Lab of Sari Agricultural Science and Natural Resource University. PDA medium (potato extract, dextrose and agar) was kept for a week at 25˚C to propagation of fungal strain. The used medium was previously sterilized in autoclave for 30 minutes. So, this fungus propagated in Wheat's bran for five days. Healthy and uniform seeds of rapeseeds were separated from rogues and infertile ones. Seeds disinfected in hypochlorite sodium 0.5% for five minute and then washed with distilled water three times. After preparing fungus spore suspension of 108 CFU per ml water, 50 g wheat' bran mixed to the soil of each pot. Twenty sterilized seeds sown in 2 cm of soil depth in 25×30 cm pot with 10 kg capacity. Copper nitrate was used to pollute treated soil. During this experiment did not used any pesticides and herbicides and all weed controlled manually. Some growth and yield related parameters such as plant height, number of secondary branches, pod number and length of primary and secondary branches, were determined. All statistical analysis were performed using SAS software (version 9.1) and mean comparisons were made by the least significant difference (LSD) test.
Results and DiscussionResults showed that increasing copper content in growth medium markedly decreased pod number in main branches in Hayola 401 while in Sarigol the maximum pod number was recorded at the 50 mg l-1 of copper nitrate. The presence of the Trichoderma, however, increased pod number in branches. Sarigol resulted more pod numbers in branches than Hayola 401 (2.5 times vs. 64%). Also, the maximum pod numbers in branches (about 1.3 fold as compared to the uninoculated control) were observed in Trichoderma inoculated plants which received 100 mg/L of copper nitrate. The maximum plant height in Hayola 401 and Sarigol (0 and 100 mg l-1 of copper nitrate, respectively) recorded when those plants inoculated with Trichoderma. The presence of the Trichoderma in the growth medium significantly improved the pod length of in main branches in Hayola 401 rather than Sarigol.
ConclusionsMany researches showed that rapeseed is a hyperaccumulatore plant for heavy metals such as copper, cadmium, nickel, zinc and lead. On the other hand, many researchers confirmed that soil beneficial microorganisms such as Trichoderma spp. could improve the growth and yield attributes of plant especially in polluted soil. In conclusion, inoculation of rapeseed plants with Trichoderma could enhance the growth characteristics of rapeseed particularly under high levels of copper in the soil. Sarigol, however, respond better than Hayola 401 in terms of yield and yield components. Since, important aspect of bioremediation is inhibition of pollutants passes through a food chain, thus, coexistence of beneficial microorganisms that capable to transform contaminants into nontoxic products are very important.

In order to evaluate the Effect of Trichoderma virens and Piriformospora indica coexistence with Enterobacter sp. on the growth and photosynthetic pigments in pepper (Capsicum annuum L.) plant an experiment was conducted during 2015 under controlled conditions. A factorial experiment based completely randomized design with three replicates was used. Factors were two levels of inoculation and non-inoculation of phosphate solubilizing bacteria, Enterobacter sp., and four levels of fungi coexistence including uninoculted control, Trichorerma virens (Tv), Piriformospora indica (Pi) and Tv. The pepper seeds were inoculated with the mentioned fungi and bacteria before sowing in the sterilized soil. The pots were kept in greenhouse for four weeks and then morphological parameters (leaf number, plant height, root length and leaf area) and aerial parts fresh and dry weights along with chlorophyll a, b, a, a/b and carotenoid contents were determined. Results indicated that aboveground fresh weights significantly increased in Pi and Tv inoculated seeds without Enterobacter as compared to the uninoculated control. Also, coexistence of Tv and Enterobacter increased root and plant dry weights (up to 58 and 40 %, respectively) and leaf and aerial parts dry weights (more than two times and 93 %, respectively) as compared to the uninoculated control. The maximum amount of carotenoid was recorded in coexistence of Pi and Enterobacter. In conclusion, results of the present study demonstrated that there was a positive effect between the growth promoting fungi, Tv and Pi, and phosphate solubilizing rhizobacteria, Enterobacter, in terms of growth parameters of pepper plant.

Sugar beet pulp is one of the sugar industries by-products which can be used for cellulase enzyme production, Enzymatic Saccharification, and alcohol production due to its high percentage of lingo-cellulosic content. Trichoderma spp. is an important fungus that produces a wide range of cellulytic enzymes. In this study, cellulase enzyme was produced by placing sugar beet pulp in Trichoderma fermentation media together with 21 gamma irradiated T. reesei mutants and then shaking at 180 rpm at 28 °C for 72 h. All isolates were screened for cellulytic enzyme production. T. r M5 mutanthad the highest level of endo-glucanase, total cellulase, and exo-glucanase enzymeactivity among the all mutants and primary parental isolates. It also had optimum ß-glucosidase activity. The protein profile of T. r M5 mutant was analyzed using SDS-PAGE test. T. r M5 had different enzymatic bands with variable molecular weight related to EG IV, Cel 3C, Cel 3D, Cel 3A, Cel 7A, Cel 6A, Cel 5A, and Cel 61A enzymes. Results showed that T. r M5 mutant had the highest efficiency for sugar beet pulp saccharification among the all mutants. Sugar beet pulp saccharification was carried out within 1 h using enzymes produced by this mutant. The amount of alcohol production from sugar released by industrial yeast stains Saccharomyces cerevisiae and Kluyveromyces marxianus was evaluated. Alcohol production in T. r M 5 was 1.5-2 times more than its parent, T. reesei.

Nowadays, the use of biofertilizer is steadily increasing in sustainable agriculture, therefore the present study was aimed to evaluate the effect of seed biopriming by Piriformospora indica and Trichoderma virens on the growth, morphological and physiological parameters of mung bean (Vigna radiate L.). Experiment was conducted as completely randomized design with three replicates in 2014. Treatments were included four levels of biopriming (control, inoculation by P. indica or T. virens and dual inoculation by P. indica and T. virens). Seeds of mung bean were sown in sterile soil and grown for four weeks and then some morphological, growth and photosynthetic pigments parameters were determined. Results showed that seed biopriming by Trichoderma, P. indica and dual inoculation increased plant height (4, 8 and 2 %, respectively) and root length (18, 31 and 13 %, respectively) as compared to the uninoculated control. However, the increase was significant only for P. indica inoculated seeds. Furthermore, shoot fresh and dry weights increased when mung bean seeds inoculated by both fungi. The maximum increase in stem, shoot and plant dry weights (5, 3 and 2 times of control) were recorded when seeds inoculated with P. indica. Also, inoculation of seeds by P. indica improved chlorophyll a, b, a+b contents (nearly 8, 15 and 9 %, respectively). In conclusion, it seems that seed biopriming of mung bean by growth promoting fungi particularly P. indica positively improved the growth attributes in early growth stages.

Seedling damping-off is a major disease of cotton in various areas of Iran that damages to cotton fieldsevery year.Recently,Trichoderma spp. areconsidered as one of the biological agents forseedling damping-off controll.Induction of plant defensive system is the most important mechanism to biocontrol ofTrichoderma spp. In this study, extra-cellular flouids derived from culture filtrates of two isolatesof Trichoderma virensaseffective biocontrol on cotton seedling damping-offcausedby Rhozoctonia solaniisolate A224 andnoneffective biocontrolisolateA442 were studied. The characteristics of elicitation activity were assayed by peroxidase and gossypol level of rootlet extracts and were evaluated by colorimetric methods and spectrophotometer. Biochemical and physical aspects of elicitore compounds of culture filtrates were measured too.The results showed that culture filtrates from effective biocontrol isolate A224 of Trichoderma virens was found to stimulate elicitore compounds (peroxidase and gossypol) in cotton radicle than noneffective biocontrolisolateA442 of T.virens.The results confirmedthese elicitors were found to be heat stable, insoluble in chloroformand sensitive to treatment by proteinase K. The elicitors are most likely proteins or glycoproteins.

The effects of bio-priming with different isolates of biological agent of Trichoderma spp. and Pseudomonas fluorescens on morphological and physiological characteristics of a bean cultivar (Yaas) as well as their effects on controlling of Rhizoctonia solani were investigated in two separate experiments. In the first experiment, different isolates of Trichoderma including Trichoderma harzianum bp4, Trichoderma virensAs10-5, Trichoderma atroviride Cs2-1 as well as one bacteria isolate of Pseudomonas fluorescens (UTPF5) were applied on bean seeds primed with zinc sulphate and salicylic acid. In this experiment using a randomized complete block design with 3 replications, several characteristics like root, shoot and seedling length and dry weight, leaf area, chlorophyll content, ‎percentage of nitrogen and iron content, and antioxidant enzymes were measured. In the second experiment, the effects of aforementioned seed treatments on controlling of pathogen was considered. Seeds primed with zinc sulphate which treated with Trichoderma harzianum bp4 had superior growth characteristics like seedling dry weight and nitrogen percentage. The highest iron content (‏256.6 mg/kg (‏detected in seeds which primed with zinc sulphate and treated with UTPF5 bacteria isolate. The seedlings of primed seeds with salicylic acid and treated with UTPF5 had the maximum activity of ascorbat peroxidase (17.4 U.mg-1proteins‏). This seed treatment also had the best control effect (77.33%) on Rhizoctonia solani.

Fusarium disease of wheat is one of the important diseases in wet and subtropical regions in Iran. Using the biological agents is effective in controlling this disease. In this experiment, were used 3 species of native Trichoderma: T. atroviridae, T. harzianum and T. virens as biological agents. Also to compare between the effects of fungicide and antagonist agents were used of Propiconazole. Tested on two wheat cultivars Falat & Moghan, in the form of spilet plot-factoriel with 3 replications in the field conditions. When spikes were in the pollination stage they were sprayed in three different times: T1 (first sprayed with Trichoderma suspensions (3×107/ml) and two days after sprayed with Fusarrium suspentions (3×105/ml)), T2 (sprayed with Fusarium and Trichoderma simultaneously) and T3 (first sprayed with Fusarrium suspentions (3×105/ml) and two days after sprayed with Trichoderma suspensions (3×107/ml)). The mean comparisions showed that all control treatments had a significant difference, with infected control treatment(p=95%), and in infected control treatment was higher infection rate and severity of pollution and was less thousand grain wighte, compared with other treatments. In other treatments, fungicide treatment was less infection rate and severity of pollution and was higher thousand grain weight and yield compared with antagonistic treatments (p=95%). In different times of sprayed in relation to infection rate and severity of pollution and yield, the results showed that the treatments which were used at T1 better results compared with the time T2 and T3. Consequently, the time T1 was known as the most efficient use Trichoderma. In relation to varieties of wheat the results showed that, between two cultivars wheat were significant difference and cultivar of moghan showed the better results compared with falat cultivar.

Evaluation of soil microorganisms and their beneficial relationships among ecosystem components is one of new topic in soil resource management for ensuring sustainable agriculture. In order to investigating effects of Trichoderma spp. and different organic manures on improvement of growth and development in soybean [Glycine max (L.) Merril.], an experiment was conducted at glasshouse in Sari Agricultural and Natural Resources Sciences University. The pot experiment was laid out factorial based on completely randomized design with four replications. Four seedbed materials [consisted of field soil as control, vermicompost and municipal waste compost (20 ton/ha) and farmyard manure (30 ton/ha)] and two species of Trichoderma (including T. harzianum and T. viridae) with a check were the treatments. Results showed that application of vermicompost, compost and farmyard manure enriched with T. viridae increased soybean root weight as much as 19.6, 37.7 and 18.3 percent, respectively. Inoculation of two fungi with farmyard manure and compost significantly increased shoot and plumelet weight. Furthermore, application of two fungi with farmyard manure and compost simultaneously increase seedling emergence percent compared to control. However, only T. harzianum and compost combination had additive effect in terms of final emergence percent. Overall, inoculation of T. harzianum could improve cumulating emergence rate (CER) compared to control.