جستجوی مقالات مرتبط با کلیدواژه "plant growth promoting bacteria" در نشریات گروه "زراعت"

Glycyrrhiza glabra L., commonly known as licorice is a perennial medicinal plant, which possesses multiple health benefits. Licorice root extract can be used for traditional medicine and food and pharmaceutical industries since it contains bioactive compounds and main ingredients, glycyrrhizin, liquiritin, and glabridin. The utilization of plant growth-promoting rhizobacteria as biofertilizers is increasingly being suggested as a way to reduce the application rate of chemical fertilizers in agricultural systems. Therefore, the aim of this study was to assess the impact of Azotobacter as one of the plant growth-promoting bacteria alone and in combination with a reduced application rate of chemical fertilizer on photosynthesis, gas exchange, and biomass production of licorice plants propagated through seeds and rhizomes. A field experiment was conducted by inoculating the seeds and rhizomes of licorice plants with Azotobacter chroococcum (Ac; strain 1087) alone or in combination with reduced level of chemical fertilizer. The five treatments for the experiment were (i) control (no inoculation and fertilization) (ii) Ac inoculation; (iii) 100% recommended N (100% N) (iv) 50% recommended N (50% N); and (v) Ac inoculation + 50% N which were evaluated in both propagation methods (seeds and rhizomes). Net photosynthesis rate, leaf transpiration rate, intracellular CO2, photosynthetic water use efficiency, chlorophyll content (SPAD value), plant height, leaf area, and shoot, root, and rhizome dry weight, and total biomass production (root + rhizome) were measured. The observed results revealed that the licorice plants produced from the rhizomes showed an increase in plant height by 75%, a four-fold increase in the leaf area, a nine-fold increase in the shoot dry weight, a 6.6-fold increase in each rhizome weight, and increase of 23-fold, 7.3-fold, and 11.1-fold in production of the rhizome, root, and total biomass respectively, compared with the plants produced from seeds. The findings also showed that Ac inoculation further influenced root and rhizome biomass production more than vegetative growth-related parameters and shoot biomass production. Integrated inoculation of Ac with 50% N applied, interestingly, improved the plant shoot dry weight by 134 and 147% and total biomass production by 149 and 94% through improving the leaf area by 180 and 114%, SPAD value by 13 and 9%, net photosynthesis rate by 119 and 15%, and water use efficiency by 43 and 42% in plants resulted from rhizomes and seeds, respectively. Moreover, results demonstrated that simultaneous inoculation of Ac and the application of 50% N showed similar results compared with the application of 100% N. These findings suggest that inoculation of A. chroococcum integrated with a reduced dose of urea can reduce the amount of nitrogen fertilization up to 50% without significantly reducing the yield of licorice produced through seeds and rhizomes. The results of this study also showed that the licorice produced from the rhizomes showed a multifold increase in various growth and yield traits compared to the licorice obtained from the seed during the first growing year. This can be considered in the production of licorice plants in different conditions, based on different production aspects.

Rice (Oryza sativa L.), as one of the most important cereals, is the main food of more than 50% of the world's population. Excessive use of chemical fertilizers in paddy fields has caused many environmental problems. Therefore, the application of biological fertilizers instead of chemical fertilizers to increase the yield of crops and produce more food is one of the important goals of sustainable agriculture, which is necessary for human life. Bacteria is an example of biological fertilizer used in agriculture, which plays an important role in improving soil structure, improving plant growth, and increasing the quantitative and qualitative yield of crops. Another biological stimulant of plants is amino acids, which can increase plant growth, improve nutrients uptake, and increase grain yield and grain quality of crops. Methionine is the precursor of growth regulators such as auxin, cytokinin, and brassinosteroids and is known as the most important growth-limiting amino acid in plants. Lysine is an essential amino acid that is involved in the germination of pollen grains, chlorophyll synthesis, and crop production. Therefore, the present study aimed to evaluate the effects of different strains of plant growth-promoting bacteria and amino acids on growth, yield, and concentration of nutrients in rice.

The field experiment was arranged as a split-plot in a randomized complete block design with three replications at the farmer's field located in Mazandaran province, Amol during 2019-2020 cropping seasons. In the present research, the plant growth-promoting bacteria at five levels (control or without bacteria [B0], P. agglomerans strain O4 [B1], P. putida strain P13 + P. agglomerans strain P5 [B2], P. koreensis strain S14 + P. vancouverensis strain S19 [B3] and combination of different strains [B4]) as the main factor and amino acids foliar application in four levels (control or without amino acids [A0], methionine [A1], lysine [A2] and methionine + lysine [A3]) as the sub-factor were considered. The plant growth-promoting bacteria at the rate of 100 g.ha-1 and amino acids at a concentration of 2.5 per thousand were applied in this study. At physiological maturity, the growth, yield components, grain yield, and nutrients uptake (NPK) in grain were measured. A combined analysis of variance was performed using SAS software version 9.2. Mean values were compared using least significant difference (LSD) test at 5% probability level.

The outcomes established that the bacteria treatment exerted a notable impact on all examined traits, excluding the count of fertile tillers per hill. Equally noteworthy, the amino acid intervention displayed significance in terms of 1000-grain weight, grain yield, and nitrogen concentration in rice grains. However, the interaction between bacteria and amino acids exhibited no significance across the quantitative and qualitative characteristics of rice. The concurrent utilization of bacteria strains, specifically B4, yielded substantial enhancements in panicle length (24.22 cm), the count of filled grains per panicle (60.30 filled grains), 1000-grain weight (28.52 g), grain yield (5097.50 kg.ha-1), and the amelioration of nutrients concentrations. Notably, nutrients like nitrogen (1.61%), phosphorus (7.04%), and potassium (1.53%) exhibited improvements in rice grains, in comparison to instances involving separate strain applications and the control group. Simultaneous foliar application of methionine and lysine amino acids resulted in maximum 1000-grain weight (26.90 g), highest grain yield (4844.73 kg.ha-1), and production of the greatest nitrogen content in grain (1.40%). In the present research, the increase in grain yield by combined application of different bacteria strains might be due to enhancing growth, improving yield components such as 1000-grain weight and filled grains number per panicle, and increasing nutrients concentration (NPK) in rice. Also, the simultaneous foliar application of methionine and lysine led to an increase in rice grain yield through increasing 1000-grain weight and improving nitrogen uptake in rice grains.

According to the results of this experiment, the combined application of the bacteria strains (P. agglomerans strain O4 + P. putida strain P13 + P. agglomerans strain P5 + P. koreensis strain S14 + P. vancouverensis strain S19) and simultaneous foliar application of methionine and lysine can play an important role in improving growth, yield and nutrients uptake in rice grains.

In order to investigate the effect of plant growth promoting rhizobacteria on grain yield and gas exchange of new dryland wheat cultivars, a factorial field experiment was counducted in a randomized complete block design with three replications on the farms of Sarablah Agricultural Research Center in the cropping seson during 2019-2020. Experimental treatments include different wheat cultivars (Sardari, Karim, Koohdasht and Rijo) and treatment of different fertilizer sources including: control (without fertilizer source), 50% N fertilizer, Azospirillum + 50% N fertilizer, Azetobacter + 50% N fertilizer, Azospirillum + Azetobacter + 50% N fertilizer and 100% N fertilizer. The results of this study showed that the interaction of cultivar×different fertilizer sources was significant on grain yield, yield components as well as gas exchanges of dryland wheat. the highest grains.spike-1 (80%), 1000-grain weight (33.3%), grain yield (86.3%), biological yield (79.9%), photosynthesis rate (81.8%), transpiration rate (74.8%), mesophilic conductance (85%), photosynthetic water use efficiency (42.3%) was obtained from the interaction of Rijo× Azospirillum+Azetobacter +50% N fertilizer and the lowest value of these traits was related to the interaction between Sardari cultivar control treatment (without fertilizer source).

Garlic (Allium sativum L.) is one of the main vegetable crops grown in Iran. Garlic occupies a prominent position among human foods, not only as a condiment, but also due to its therapeutic properties, attributed to the presence of bioactive compounds (25). Garlic yield are varied with agricultural practices and cultivar. Application of the required nutrients through chemical fertilizers alone can have deleterious effect on soil health and can lead to unsustainable yields, while integration of chemical fertilizers with organic manures and biofertilizers can maintain soil health and soil productivity (3). Numerous bacteria are beneficial for plant productivity. Free-living soil bacteria such as Pseudomonas, Azotobacter and Azospirillum spp could add nutrients through the natural processes of nitrogen fixation, solubilizing phosphorus, and stimulating plant growth through the synthesis of growth-promoting substances (20 and 26). Hence, this experiment carried out in order to evaluate the effect of chemical, organic and bio-fertilizers on yield and some physiological characteristics of landrace garlic in Guilan climatic condition. This experiment was performed in 2016-2017 cropping season as split plot based on complete block design with three replications in Rasht, Iran. Three nitrogen sources including vermicompost (15 ton/ha), urea (100 kg N/ha), integrated management nutrient (7.5 ton/ha + 50 kg N/ha) and 10 biological inoculations including without inoculation as control, Azospirillum brasilense, Azospirillum lipoferum, Pseudomonas putida, Pseudomonas fluorescens, Azotobacter, Azospirillum + Pseudomonas, Azospirillum + Azotobacter, Pseudomonas + Azotobacter, Azospirillum + Pseudomonas + Azotobacter comprised experimental treatments. Results showed that the maximum plant height, leaf numbers, biological weight per plant and bulb yield were obtained under the application of chemical nitrogen fertilizer along with Pseudomonas + Azospirillum spp bacteria. Also, there was a positive and significant correlation between bulb yield and some characteristic such as plant height, leaf numbers and biological weight per plant. In addition, the simultaneous application of Azospirillum and Azotobacter biological fertilizers under using vermicompost caused to enhance bulb yield. In this experiment, simultaneous usage of all studied bio-fertilizers enhanced bulb yield under integrated nutrition system. In general, bulb yield and its attributes showed difference responses to the application of chemical, organic and bio-fertilizers. Based on results of this experiment, different biological fertilizers could be beneficial related to type of nutrition systems for bulb yield enhancement. In addition, the application of Azospirillum + Pseudomonas could be recommendable to improve biological and bulb yield of garlic in conventional agriculture and under region climatic condition.

Plant growth promoting rhizobacteria has been identified as an alternative to chemical fertilizer to enhance plant growth and yield directly and indirectly. Use of rhizosphere free living bacteria is one of the methods for crop production and leads to improvement of resources absorption. In order to study of yield, yield components and radiation use efficiency, under application of PGPR condition, an experiment was carried out in 2008 growing season at Agriculture and natural resources research station of Mashhad. The cultivars selected from three rapeseed species belong to Brassica napus, Brassica rapa and Brassica juncea (landrace, BP. 18، Goldrush، Parkland، Hyola330، Hyola401). Experimental factorial design was randomized in complete block with three replications. Treatments included six varieties of Rapeseed and inoculations were four levels as non–inoculation, inoculation with P. fluorescens169, P. putida108 and use then together. Results showed that strains of fluorescent pseudomonas bacteria had greatest effects on yield and yield components cultivars. A significant difference in the number of pods per plant and 1000 seed weight observed. The cultivars were different in all treats except 1000 seed weight. Overall results indicated that application of growth stimulating bacteria in combination with different cultivars, had a positive effect growth, yield characteristics of plant varieties of rapeseed plants.

In other to evaluate the effects of Nitroxin biofertilizer and different levels of nitrogen fertilizer، on yield and yield components of winter wheat (Triticum aestivum)، a field experiment was conducted in Research Station، College of Agriculture، Ferdowsi University of Mashhad in 2009-2010. The experiment was conducted as a factorial arrangement based on completely randomized block design with three replications. The experimental treatments were all combination of nitroxin biofertilizer in two levels (inoculated with nitroxin and non inoculated)، and nitrogen fertilizer in six levels (0، 10، 20، 40، 80، 160 and 320 Kg ha-1 urea). Result showed that combination of biofertilizer with different levels of N fertilizer، had significant effect (p)

To study the effects of urea fertilizer and bio-fertilizers on grain yield and important agronomic traits in maize (Zea mays L. Sc704), a split plot experiment based on randomized complete block design with three replications was conducted in Payame Noor University of Khash Research Field during 2011-2012 cropping season. Four different levels of urea consisting of zero, 25% (equal to 87.5 kg.ha-1), 50% (equal to 175 kg.ha-1) and 100% (equal to 350 kg.ha-1) based on the results of soil analysis were assigned to main plot and bio-fertilzers, including Azotobacter, Azospirillum and non- inoculation, to sub plot. Results indicated that nitrogen fertilizer affected the traits under study significantly. The highest and lowest plant height, the number of seed per ear row, the number of grain per row, ears.m-2, 1000 kernel weight, seed yield, bilogocal yield and seed protein content were obtained by using 100% nitrogen fertilizer and control (zero level of urea) respectively. Using bio-feretlizers also had a significant effect on traits under study. Bio-fertilizer had positive effect on seed yield and yield components. Thus, there was a seed yield increase of 8.4% and 8.2% by using Azotobacter and Azospirillum compared to the non- inoculated seeds, respectively.

In order to investigate the effects of plant growth promoting bacteria on growth characteristic of wheat، an experiment was conducted at the Research Greenhouse، Faculty of Agriculture، Ferdowsi University of Mashhad، Iran، in year 2009. A completely randomized design based on factorial arrangement (3×6) with three replications was used. The first factor consisted of three cultivars of wheat (Chamran، Sayonez and Gaskogen) and the second one was biofertilizer types (phosphate suloblizing bacteria، biophosphore، nitroxin، nitragin، mixed and control). Results showed that the effects of biofertilizers were significant on leaf area، root volume، shoot and root length criteria. Moreover، the difference between cultivars on emergence rate، leaf area، leaf number per plant، leaf dry weight، total dry weight and leaf to root dry weight ratio، were significant. The highest and the lowest emergence rate were observed at Gascogen (0. 8 seed per 12 hour) and Chamran (0. 56 seed per 12 hour) cultivars، respectively. The interaction effects of wheat cultivars and biofertilizers were significant on all studied characteristics (emergence rate، leaf area، specific leaf area، leaf number per plant، leaf dry weight، root dry weight، total dry weight، leaf to root dry weight ratio، shoot length، root length، root to shoot length ratio، mean leaf length and root volume) unless emergence percentage. Overall، our result indicated that biofertilizers had a useful and effective function on improvement of growth characteristics of wheat.