Responses of agronomically important crops to inoculation with Azospirillum

2001 ◽  
Vol 28 (9) ◽  
pp. 871 ◽  
Author(s):  
Sofie Dobbelaere ◽  
Anja Croonenborghs ◽  
Amber Thys ◽  
David Ptacek ◽  
Jos Vanderleyden ◽  
...  

This paper originates from an address at the 8th International Symposium on Nitrogen Fixation with Non-Legumes, Sydney, NSW, December 2000 Azospirilla are free-living rhizobacteria that are able to promote plant growth and increase yields in many crops of agronomic importance. It is assumed that the bacteria affect plant growth mainly by the production of plant growth promoting substances, which leads to an improvement in root development and an increase in the rate of water and mineral uptake. In the present review, we discuss the physiological responses of the plant roots to inoculation with Azospirillum, and report on field and greenhouse experiments carried out with these bacteria during 1994–2001 in Belgium, Uruguay, Mexico and Israel.

GIS Business ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 425-431
Author(s):  
Subin Thomas ◽  
Dr. M. Nandhini

Biofertilizers are fertilizers containing microorganisms that promote plant growth by improving the supply of nutrients to the host plant. The supply of nutrients is improved naturally by nitrogen fixation and solubilizing phosphorus. The living microorganisms in biofertilizers help in building organic matter in the soil and restoring the natural nutrient cycle. Biofertilizers can be grouped into Nitrogen-fixing biofertilizers, Phosphorous-solubilizing biofertilizers, Phosphorous-mobilizing biofertilizers, Biofertilizers for micro nutrients and Plant growth promoting rhizobacteria. This study conducted in Kottayam district was intended to identify the awareness and acceptance of biofertilizers among the farmers of the area. Data have been collected from 120 farmers by direct interviews with structured questionnaire.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luz K. Medina-Cordoba ◽  
Aroon T. Chande ◽  
Lavanya Rishishwar ◽  
Leonard W. Mayer ◽  
Lina C. Valderrama-Aguirre ◽  
...  

AbstractPrevious studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1071
Author(s):  
Minchong Shen ◽  
Jiangang Li ◽  
Yuanhua Dong ◽  
Hong Liu ◽  
Junwei Peng ◽  
...  

Microbial treatment has recently been attracting attention as a sustainable agricultural strategy addressing the current problems caused by unreasonable agricultural practices. However, the mechanism through which microbial inoculants promote plant growth is not well understood. In this study, two phosphate-solubilizing bacteria (PSB) were screened, and their growth-promoting abilities were explored. At day 7 (D7), the lengths of the root and sprout with three microbial treatments, M16, M44, and the combination of M16 and M44 (Com), were significantly greater than those with the non-microbial control, with mean values of 9.08 and 4.73, 7.15 and 4.83, and 13.98 and 5.68 cm, respectively. At day 14 (D14), M16, M44, and Com significantly increased not only the length of the root and sprout but also the underground and aboveground biomass. Differential metabolites were identified, and various amino acids, amino acid derivatives, and other plant growth-regulating molecules were significantly enhanced by the three microbial treatments. The profiling of key metabolites associated with plant growth in different microbial treatments showed consistent results with their performances in the germination experiment, which revealed the metabolic mechanism of plant growth-promoting processes mediated by screened PSB. This study provides a theoretical basis for the application of PSB in sustainable agriculture.


2016 ◽  
Vol 46 (2) ◽  
pp. 149-158 ◽  
Author(s):  
Ariana Alves Rodrigues ◽  
Marcus Vinicius Forzani ◽  
Renan de Souza Soares ◽  
Sergio Tadeu Sibov ◽  
José Daniel Gonçalves Vieira

ABSTRACT Microorganisms play a vital role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study aimed at isolating and characterizing plant growth-promoting bacteria associated with sugarcane, as well as assessing their ability to promote plant growth. Endophytic bacteria from leaf, stem, root and rhizosphere were isolated from the RB 867515 commercial sugarcane variety and screened for indole acetic acid (IAA) production, ability to solubilize phosphate, fix nitrogen and produce hydrogen cyanide (HCN), ammonia and the enzymes pectinase, cellulase and chitinase. A total of 136 bacteria were isolated, with 83 of them presenting some plant growth mechanism: 47 % phosphate solubilizers, 26 % nitrogen fixers and 57 % producing IAA, 0.7 % HCN and chitinase, 45 % ammonia, 30 % cellulose and 8 % pectinase. The seven best isolates were tested for their ability to promote plant growth in maize. The isolates tested for plant growth promotion belong to the Enterobacteriaceae family and the Klebsiella, Enterobacter and Pantoea genera. Five isolates promoted plant growth in greenhouse experiments, showing potential as biofertilizers.


2005 ◽  
Vol 82 (3) ◽  
pp. 85-102 ◽  
Author(s):  
C.L. Doumbou ◽  
M.K. Hamby Salove ◽  
D.L. Crawford ◽  
C. Beaulieu

Actinomycetes represent a high proportion of the soil microbial biomass and have the capacity to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to protect plants against plant diseases. This review focuses on the potential of actinomycetes as (a) source of agroactive compounds, (b) plant growth promoting organisms, and (c) biocontrol tools of plant diseases. This review also addresses examples of biological control of fungal and bacterial plant pathogens by actinomycetes species which have already reached the market or are likely to be exploited commercially within the next few years.


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