Associative Azospirillum Brasilense Research Articles

Productivity and nutritive value of Tifton 85 bermudagrass inoculated with Azospirillum brasilense in association with nitrogen fertilization

Productivity and nutritive value of Tifton 85 bermudagrass inoculated with Azospirillum brasilense in association with nitrogen fertilization

Ефективність використання асоціативних діазотрофів для підвищення урожайності тритикале ярого

Goal. To study the effectiveness of the use of associative Azospirillum brasilense diazotrophs 10/1 to increase the yield and improve grain quality of spring triticale. Methods. Microbiology, gas chromatography, field experiment, and statistical. The objects of study — plants of spring triticale of varieties Oberig Kharkivskii, the strain of associative nitrogen-fixing bacteria Azospirillum brasilense 10/1. Field experiments were carried out in conditions of Ukrainian Polissia (Institute of Agricultural Microbiology and Agroindustrial Manufacture, NAAS, Chernihiv). The inoculation of seeds of triticale was carried out with 3-days culture of bacteria A. brasilense 10/1 for 2 h before seeding at the rate of 200–300 thousand bacterial cells per seed. Processing of experimental data was performed using the computer program Microsoft Office Excel. Results. It is established that the strain A. brasilense 10/1 positively influenced the growth and development of spring triticale due to improved nitrogen nutrition of plants and the ability to produce growth-stimulation substances. Use of the strain A. brasilense 10/1 for preplant bacterization of seeds triticale provided the increase in crop yield by 0.5 t/ha, or of 16.39% compared to control. Positive influence is revealed on a mass of grains in one ear and weight of 1000 grains. These indicators increased in the variant with inoculation on average on 16.8 and 11.9%, respectively. Also by inoculation of spring triticale with a promising strain of A. brasilense 10/1 the protein content in the grain increased to 14.06%, wet gluten – to the 35, 17, full-scale mass of grain increased by 7.3%. Conclusions. Taking into account the positive effect of associative nitrogen-fixing bacteria A. brasilense 10/1 on the growth and development of triticale plants, perspective variant is the creation of a biological product based on the strain for increasing the yield and improving the quality of the resulting products.

Agronomic performance and sweet corn quality as a function of inoculant doses (Azospirillum brasilense) and nitrogen fertilization management in summer harvest

ABSTRACT The inoculation of sweet corn seeds with Azospirillum brasilense in association to nitrogen fertilizer may be an agronomic alternative for increasing the crop yield and net income of plant growers. Therefore, the aim of this study was to investigate the effect of the different doses of inoculant (Azospirillum brasilense) associated to the nitrogen fertilization management on the phenotypic traits of one sweet corn hybrid in summer growing periods, under supplemental irrigation, in the Northwestern Parana state, Brazil. The experiment followed the complete randomized block design with four replications. The treatments were: i) five inoculant doses (0.0, 50, 100, 150 and200 mL∙ha–1) containing Azospirillum brasilense; ii) two N doses (0.0 and 30.0 kg∙ha–1) applied at sowing time; and iii) two topdressing doses of N (0.0 and 110.0 kg∙ha–1) applied at the V4 stage. The sweet corn hybrid RB 6324 was evaluated in 2012/2013, 2013/2014 and 2014/2015. The traits plant height (ranged from 2.11 to 2.26 m), leaf area index (3.33 to 4.32), crop yield (7.21 to 10.43 Mg.ha–1), and the sugar kernel contents (38.46 to 43.31%) and protein (12 to 12.81%) were positively influenced by the seed inoculation with A. brasilense, and the nitrogen fertilizer increased all the traits except the kernel total sugars. The dose of inoculant that provided the best agronomic result was 100 mL∙ha–1 in conjunction with the application of N either at sowing or topdressing.

Yield of Cowpea Genotypes Inoculated With Bradyrhizobium and Azospirillum brasilense in Association With Phosphate Fertilization in Amazonian Soil

The use of inoculants containing N2-fixing bacteria increases every year in cowpea crop in the North and Northeast regions of Brazil. In this context, this study aimed to evaluate the effects of inoculation with Bradyrhizobium sp. and Azospirillum brasilense in association with phosphate fertilization on the vegetative development, nodulation and yield of cowpea genotypes grown in Southern Rondônia state, Brazil. The experiment was conducted from February to May 2018, in the municipality of Colorado do Oeste, RO. The experimental design was randomized blocks in 4 × 3 × 2 factorial scheme, corresponding to four dose of phosphorus (0, 80, 120 and 160 kg ha-1 of P2O5); absence, inoculation and co-inoculation with rhizobacteria; two cowpea genotypes (White and Butter), with three replicates. Cowpea seeds were inoculated with the commercial inoculant TotalNitro Cowpea with strains of Bradyrhizobium sp. (Semia 6462 and Semia 6463); co-inoculation was performed using the commercial product, containing a combination of strains of Azospirillum brasilense, both in liquid formulation. Co-inoculation (Bradyrhizobium sp.+ Azospirillum brasilense) did not influence the production components of cowpea plants. Inoculation with Bradyrhizobium sp. associated with phosphate fertilization of 120 kg ha-1 of P2O5 was sufficient to promote maximum growth and development of cowpea plants in Amazonian soil. The genotype White had higher capacity of nodulation, dry matter production and grain yield. Inoculation of Bradyrhizobium sp. increased N and P contents in the leaves. The genotype Butter was superior to the genotype White with respect to the accumulation of P, K, Ca and Mg in the leaves.

English

Studies on co-inoculation of strains with high symbiotic potential, as well as the use of humic substances are of great importance for obtaining increases in nodulation, biological nitrogen fixation and yield of the bean crop. Thus, this study aimed to evaluate the effects of the co-inoculation of Rhizobium tropici and Azospirillum brasilense in association with humic acids and nitrogen (N) on the behavior of different bean genotypes, cultivated in a protected environment. The experiment was carried out at the Federal Institute of Education, Science and Technology of Rondonia, Campus of Colorado do Oeste-RO, Brazil, from February to April 2015. The experimental design was completely randomized, with four replicates. Common bean seeds of the cultivars ‘Perola’ and ‘BRS Esplendor’ were previously co-inoculated with Azospirillum brasilense and Rizhobium tropici. Shoot dry matter production in the cultivar ‘Perola’ increased by 76.12% when co-inoculated with rhizobacteria. N use efficiency in the bean cultivar ‘Perola’ is higher when co-inoculated with Azospirillum brasilense and Rizhobium tropici, confirming that co-inoculation alone is sufficient to provide the N necessary for plant development. Key words: Phaseolus vulgaris L., Rhizobium tropici, Azospirillum brasilense, biological N fixation (BNF).

English

The association of Cymbopogon winterianus (Citronella), a member of the Poaceae family, with the N2-fixing bacteria, Azospirillum was examined to evaluate possible benefits for agriculture. The nodules on citronella were induced using plant growth regulator 2,4-dichlorophenoxyacetic acid (2,4-D) 1.0 ppm in nitrogen free Hoagland’s solution. Concentration of 2,4-D greater than 1.0 ppm caused stunning and death, while concentration of 2,4-D less than 1.0 ppm has no obvious effect on seedling growth. The presence of nitrogenase activity (acetylene reduction assay) and leghemoglobin (hemoprotein found in the nitrogen-fixing root nodules) was noticed in the plants treated with Azospirillum either alone or with nodulated plants, but higher activity was noticed in nodulated Azospirillum treated plants. These results confirmed the nitrogenase activity of Azospirillum brasilense in association with 2,4-D induced nodules of citronella. After transplanting to pots, it was noticed that nodulated and Azospirillum - treated plants showed higher chlorophyll content in leaf, enhanced nitrate reductase (NR) activity, leading to higher yield as compared to the control plants (non-nodulated). The nodulated plants treated with Azospirillum also had higher physiological activities as compared to plants treated only with Azospirillum. The results provide evidence that the plants belonging to the family Poaceae are potentially able to create a symbiosis with diazotropic bacteria, which colonize para-nodule tissue intracellularly, promoting a higher level of nitrogen (N2) fixation leading to better growth and plant development.   Key words: Cymbopogon, nodulation, 2,4-D, Azospirillum brasilense, nitrogen fixation, oil yield.

Effects of Diverse Habitat Biofertilizers on Yield and Nitrogen Balance in Plant–Ratoon Crop Cycle of Sugarcane in Subtropics

Three nitrogen fixing biofertilizers of diverse habitat; endophytic Gluconacetobacter diazotrophicus, free living Azotobacter chrococcum and associative Azospirillum brasilense were tested in field condition for a complete sugarcane crop cycle of one plant and a ratoon crop at different levels of N input for enhancing crop productivity and soil N balance. Different biofertilizers increased the crop yield at all nitrogen levels but the maximum increase was recorded at N75 as compared to N150. G. diazotrophicus based biofertilizer was found to be the best in terms of crop yield production followed by its combination with A. chrococcum and A. brasilense. PFP for nitrogen was more in plant crop (9–38%) than the ratoon crop (4–24%) due to different biofertilizers. Apparent N balance indicated a contribution of 52.3–216.7 kg N ha−1 in plant crop and from 65 to 225.3 kg N ha−1 in ratoon crop due to biological nitrogen fixation in different biofertilizer × N treatments. The maximum N contribution was recorded with G. diazotrophicus and minimum with A. brasilense in a plant-ratoon cycle of sugarcane crop. Overall field inoculations of sugarcane by diazotrophic biofertilizers are highly beneficial and of tested biofertilizers G. diazotrophicus based biofertilizer is most efficient in terms of higher cane yield, commercial cane sugar production, efficient N utilization and maintaining positive N balance.

Nodule-like Structures Induced on the Roots of Maize Seedlings by the Addition of Synthetic Auxin 2,4-D and its Effects on Growth and Yield

Induction of para-nodules on maize contributed to increase in yield. The nodules on maize (Zea mays L.) cv. Kiran were induced using plant growth regulator 2,4-D (lppm) in nitrogen free Hoagland solution. Concentrations of 2,4-D greater than lppm caused stunting and death, while concentrations less than lppm has no obvious effect on seedling growth. The associative symbiosis (using Azospirillum) was noticed in the nodulated and non-nodulated maize plants. The presence of nitrogenase activity (acetylene reduction assay) and leghemoglobin was noticed in the plants treated with Azospirillum either alone or with nodulated plants, but higher activity was noticed in the nodulated Azospirillum treated plants. The 2,4-D induced nodule like structures provided niche for the establishment of the bacteria, thereby enhancing nitrogen fixation in the nodulated roots. These results confirmed the nitrogenase activity of Azospirillum brasilense in association with the 2,4-D induced nodules of maize. After transplanting in the pots, it was noticed that nodulated and Azospirillum treated plants showed higher chlorophyll content in leaf, enhanced NR activity leading to higher yield as compared to controlled plants (non-nodulated). The nodulated plants treated with Azospirillum had higher physiological activities as compared to only Azospirillum treated plants. Thus, the gramineous plants are potentially able to create a symbiosis with diazotropic bacteria, which colonize para-nodule tissue intracellularly, promoting a higher level of N2 fixation for the better growth and development of the plants.

Field release of genetically marked Azospirillum brasilense in association with Sorghum bicolor L.

The agronomic impact of genetically tagged azospirilla ( Azospirillum brasilense) was assessed in open field and their fluctuation were monitored in the soil/rhizosphere. Strain performance, upon inoculation of sorghum, was evaluated over a two-years period; agronomic treatments included nitrogen application (0, 80, 160 kg ha(-1)), and types of inoculant (Sp245 lacZ, Sp6 gusA, Sp6 IAA++ gusA). Grain yield was higher for inoculated seed plots than in non-inoculated ones, whereas nitrogen content, biomass of plant residues and nitrogen in plant residues gave values that were not statistically different. Root length density (RLD) of sorghum at the end of the stem elongation stage was affected only by the indole-3-acetic acid (IAA) overproducer Azospirillum strain ( A. brasilense Sp6 IAA++ gusA) with respect to the normal IAA producer ( A. brasilense Sp6 gusA), being higher in the first 40 cm of depth, notwithstanding the level of nitrogen fertilization. The traceability of the released genetically modified strains enabled to monitor their ability to colonise soil and roots. Moreover, the genetic modification per se vs. the non-modified counterpart, did not affect the culturable aerobic population in soil, microfungi, streptomycetes, fluorescent pseudomonads, soil microbial biomass, or some microbial activities, all selected as important indicators.