scholarly journals RATES OF APPLICATION OF Azospirillum brasilense IN TOMATO CROP

2018 ◽  
Vol 5 (4) ◽  
pp. 81-87 ◽  
Author(s):  
Neberson De Souza Antunes De Lima ◽  
Gabriel Felipe Vogel ◽  
Rubens Fey

The use of plant growth-promoting bacteria (PGPB) may be a promising agronomic practice to improve the growth and productivity of vegetables. The objective of this work was to evaluate the effect of inoculation of Azospirillum brasilense on plant growth and tomato fruit production. Two experiments were carried out: the first one evaluating the growth of the plants in a greenhouse and the second one evaluating the production of fruits under field conditions. The experimental design used in two experiments was the completely randomized 2 x 5 factorial scheme, with four replications. The treatments resulted from the combination of two tomato cultivars (Gaúcho Melhorado and San Marzano) and four inoculant doses (0; 2; 4; 6 e 8 mL kg-1 of seed) containing the Ab-V5 and Ab-V6 strains of A. Brasilense. The application of inoculant containing A. brasilense improved the growth and dry matter production of tomato cultivars Gaúcho Melhorado and San Marzano. The highest values of plant height, stem diameter, root length, root volume, relative chlorophyll content and dry matter of shoots and roots are obtained with the dose of 4 to 6 mL kg-1 of inoculant, allowing to infer that the maximization of plant growth and the production of tomato fruits with the application of inoculant containing Azospirillum brasilense can be obtained with the use of approximately 5.0 mL kg-1 of seeds for tomato cultivars.

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Mariana S. Santos ◽  
Artur B. L. Rondina ◽  
Marco A. Nogueira ◽  
Mariangela Hungria

Seed treatment with chemical pesticides is commonly used as an initial plant protection procedure against pests and diseases. However, the use of such chemicals may impair the survival and performance of beneficial microorganisms introduced via inoculants, such as the plant growth-promoting bacterium Azospirillum brasilense. We assessed the compatibility between the most common pesticide used in Brazil for the treatment of maize seeds, composed of two fungicides, and one insecticide, with the commercial strains Ab-V5 and Ab-V6 of A. brasilense, and evaluated the impacts on initial plant development. The toxicity of the pesticide to A. brasilense was confirmed, with an increase in cell mortality after only 24 hours of exposure in vitro. Seed germination and seedling growth were not affected neither by the A. brasilense nor by the pesticide. However, under greenhouse conditions, the pesticide affected root volume and dry weight and root-hair incidence, but the toxicity was alleviated by the inoculation with A. brasilense for the root volume and root-hair incidence parameters. In maize seeds inoculated with A. brasilense, the pesticide negatively affected the number of branches, root-hair incidence, and root-hair length. Therefore, new inoculant formulations with cell protectors and the development of compatible pesticides should be searched to guarantee the benefits of inoculation with plant growth-promoting bacteria.


2015 ◽  
Vol 81 (19) ◽  
pp. 6700-6709 ◽  
Author(s):  
Maria Isabel Stets ◽  
Sylvia Maria Campbell Alqueres ◽  
Emanuel Maltempi Souza ◽  
Fábio de Oliveira Pedrosa ◽  
Michael Schmid ◽  
...  

ABSTRACTAzospirillumis a rhizobacterial genus containing plant growth-promoting species associated with different crops worldwide.Azospirillum brasilensestrains exhibit a growth-promoting effect by means of phytohormone production and possibly by N2fixation. However, one of the most important factors for achieving an increase in crop yield by plant growth-promoting rhizobacteria is the survival of the inoculant in the rhizosphere, which is not always achieved. The objective of this study was to develop quantitative PCR protocols for the strain-specific quantification ofA. brasilenseFP2. A novel approach was applied to identify strain-specific DNA sequences based on a comparison of the genomic sequences within the same species. The draft genome sequences ofA. brasilenseFP2 and Sp245 were aligned, and FP2-specific regions were filtered and checked for other possible matches in public databases. Strain-specific regions were then selected to design and evaluate strain-specific primer pairs. The primer pairs AzoR2.1, AzoR2.2, AzoR5.1, AzoR5.2, and AzoR5.3 were specific for theA. brasilenseFP2 strain. These primer pairs were used to monitor quantitatively the population ofA. brasilensein wheat roots under sterile and nonsterile growth conditions. In addition, coinoculations with other plant growth-promoting bacteria in wheat were performed under nonsterile conditions. The results showed thatA. brasilenseFP2 inoculated into wheat roots is highly competitive and achieves high cell numbers (∼107CFU/g [fresh weight] of root) in the rhizosphere even under nonsterile conditions and when coinoculated with other rhizobacteria, maintaining the population at rather stable levels for at least up to 13 days after inoculation. The strategy used here can be applied to other organisms whose genome sequences are available.


Author(s):  
Mahmut DAŞCI ◽  
N. Zeynep YILDIRIM ◽  
M. Kerim GÜLLAP ◽  
Binali ÇOMAKLI ◽  
Ramazan ÇAKMAKÇI ◽  
...  

1999 ◽  
Vol 45 (6) ◽  
pp. 441-451 ◽  
Author(s):  
Yoav Bashan ◽  
Adriana Rojas ◽  
M Esther Puente

Survival and development of cactus transplants in urban, disturbed areas of the desert near La Paz, Baja California Sur, Mexico, was monitored. Young plants of three species of pachycereid cacti (Pachycereus pringlei, Stenocereus thurberi, and Lophocereus schottii) inoculated with the plant growth promoting bacterium Azospirillum brasilense in an eroded area (a dirt road) had a high survival rate and developed more rapidly compared with uninoculated control plants during a 3.5-year period after transplantation. Soil erosion in the inoculated experimental area diminished. Small, but significant soil accumulated in association with the growth of cactus roots into the wind-deposited dust. One demonstrated mechanism for stabilizing dust was by the upward growth of small roots during the rainy season into the deposited dust. Azospirillum brasilense survived well in the rhizospheres of these cacti for 2 years, but not in root-free soil. This study demonstrated the feasibility of using bacterial inoculation of cacti to enhance their establishment in disturbed areas, with the potential to stabilize soil.Key words: Azospirillum, beneficial bacteria, cactus, plant inoculation, plant growth promoting bacteria, PGPR, soil erosion, soil reclamation.


2010 ◽  
Vol 34 (2) ◽  
pp. 361-369 ◽  
Author(s):  
Adriana Giongo ◽  
Anelise Beneduzi ◽  
Adriana Ambrosini ◽  
Luciano Kayser Vargas ◽  
Marcos Roberto Stroschein ◽  
...  

Two bacterial strains that amplified part of the nifH gene, RP1p and RP2p, belonging to the genus Enterobacter and Serratia, were isolated from the rhizoplane of Lupinus albescens. These bacteria are Gram-negative, rod-shaped, motile, facultative anaerobic, and fast-growing; the colonies reach diameters of 3-4 mm within 24 h of incubation at 28 ºC. The bacteria were also able to grow at temperatures as high as 40 ºC, in the presence of high (2-3 % w/v) NaCl concentrations and pH 4 -10. Strain RP1p was able to utilize 10 of 14 C sources, while RP2p utilized nine. The isolates produced siderophores and indolic compounds, but none of them was able to solubilize phosphate. Inoculation of L. albescens with RP1p and RP2p strains resulted in a significant increase in plant dry matter, indicating the plant-growth-promoting abilities of these bacteria.


2005 ◽  
Vol 51 (6) ◽  
pp. 511-514 ◽  
Author(s):  
Qiaosi Li ◽  
Saleema Saleh-Lakha ◽  
Bernard R Glick

Carnation cuttings treated with non-transformed and 1-aminocyclopropane (ACC) deaminase-containing Azospirillum brasilense Cd1843 produced significantly more roots than untreated controls and fewer roots than cuttings treated with 0.1% indolebutyric acid (IBA). The roots produced by cuttings treated with ACC deaminase-containing Azospirillum brasilense Cd1843 were the longest roots resulting from any of the treatments, followed by non-transformed Azospirillum brasilense Cd1843, 0.1% IBA, and treatment with water. The results are interpreted in terms of a previously proposed model of bacterial promotion of plant growth by ACC deaminase and indoleacetic acid, and may have implications for the use of plant growth-promoting bacteria in the flower industry.Key words: ACC deaminase, carnation, cuttings, rooting, Azospirillum brasilense.


2019 ◽  
pp. 2003-2014
Author(s):  
Paola Andrea Escobar Diaz ◽  
Noemi Carla Baron ◽  
Everlon Cid Rigobelo

The use of plant growth-promoting bacteria (PGPB) is a promising alternative method to improve plant efficiency in the utilization of chemical fertilizers, enabling a reduction of fertilizer application on crops. This study aimed to evaluate the potential of ten Bacillus strains (eight B. subtilis, one B. velezensis and one B. amyloliquefaciens) to promote growth in cotton plants under greenhouse conditions. The experiment was performed in a completely randomized design with 11 treatments and five replicates under greenhouse conditions. The parameters related to plant growth from treatments that received the bacterial isolates were compared to the control. The parameters analyzed were shoot dry matter, root dry matter, total dry matter, plant height, nitrogen content and phosphorus content in soil and in plants. The highest root dry matter was 1.24 g for the isolate 263. The total dry matter was 4.0 g for the isolate 248 and 3.54 g for the isolate 290. The highest chlorophyll content was 28 µg/cm2 for the isolate 290. The higher N content in shoot dry matter was 28 g of N for the isolate 290, 26 g for the isolate 248 and 25 g for the isolate 320. The improved P efficiency use was 32% for the isolate 248, 28% for the isolate 188 and 27% for the isolate 274. These results strongly confirm that B. subtilis isolates 248, 290 and 263 may represent a good alternative as plant growth-promoting endophytes to cotton crops, as they positively affected several parameters evaluated, such as root and shoot dry matter and phosphorus content in the soil. In addition, the parameters evaluated can strongly and positively affect plant yield. However, some isolates of B. subtilis did not promote plant growth and most likely failed as bioinoculants. This result shows the importance of properly identifying the isolate for bioinoculation to achieve success in promoting plant growth.


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