Biochemical and molecular characterization of DAPG-producing plant growth-promoting rhizobacteria (PGPR) of groundnut (Arachis hypogaea L.)

Abstract

Plant growth-promoting rhizobacteria (PGPR) thrive in the rhizosphere of plants and play a beneficial role in plant growth, and development along with biocontrol activities. The present study was undertaken with the aim of developing rhizobacterial inoculants for groundnut for enhancement of growth and yield and suppression of major soil-borne fungal diseases caused by Sclerotium rolfsii (stem rot) and Aspergillus niger (collar rot). Out of a total of 154 rhizobacterial isolates obtained from groundnut rhizosphere, 78 isolates were selected on the basis of in vitro antifungal activities against three major soil-borne fungal pathogens of groundnut, i.e. Aspergillus niger, Aspergillus flavus and Sclerotium rolfsii. The selected isolates were further screened for the production of 2,4-Diacetylphloroglucinol (2,4-DAPG) by the gene specific PCR amplification of phlD gene. A total of 11 rhizobacterial isolates were found to have DAPG-producing genes and selected for further studies. Gene specific primers were also used for characterization of the isolates for plant growth-promoting and biocontrol traits. The qualitative and quantitative estimation of the various attributes of the isolates were also carried out. Majority of the isolates showed production of IAA, siderophores and fluorescent pigments. The DAPG-producing rhizobacterial isolates have great potential as bio-inoculants for groundnut crop for suppressing soil-borne fungal pathogens and to enhance growth and yield.

Assessment of nematicidal properties of fluorescent pseudomonads using peanut root-knot nematode, Meloidogyne arenaria

“…The DAPG-producing fluorescent pseudomonads, discussed in this work, have been isolated from the peanut rhizosphere and exhibit multiple plant growth promoting and biocontrol abilities. These pseudomonads, besides controlling plant parasitic nematodes and soil-borne fungal diseases, also promote plant growth of peanut and enhance yield (Sherathia et al, 2016). In field trials, these DAPG-producing fluorescent pseudomonads have proven successful in enhancing peanut yields and reducing the incidences of major soil-borne fungal diseases (Bhayani et al, 2013;Dey et al, 2013).…”

Use of Plant Growth-Promoting Rhizobacteria in Maize and Sugarcane: Characteristics and Applications

“…Both antibiotics and toxins have been identified as being produced by certain rhizospheric bacteria (Nakkeeran et al, 2013). These include amphysines, phenazines, 2-4-diacetylfloroglucinol, pioluteorin, pyrrolnitrin, hydrogen cyanide (HCN), oomycins, polymyxin, circulin, colistin, tensin, tropolone, and cyclic lipopeptides (Maksimov et al, 2011;Pandya and Saraf, 2014;Wani and Khan, 2014;Sherathia et al, 2016).…”

Effect of biocontrol and promotion of peanut growth by inoculating Trichoderma harzianum and Bacillus subtilis under controlled conditions and field

“…Revista Mexicana de FITOPATOLOGÍA Mexican Journal of Phytopathology atender a estas limitantes surge como alternativa el biocontrol en el marco de un manejo sustentable de los cultivos, con la finalidad de mejorar la productividad a través del incremento en la disponibilidad de nutrientes y la protección a fitopatógenos (Sherathia et al, 2016). Los productos empleados en el control biológico, son preparaciones de células vivas o latentes de microorganismos que aplicados al suelo o a la semilla, favorecen la relación plantarizósfera (Bashan et al, 2013).…”

“…Although the use of synthetic fungicides has been the main tool for controlling this kind of diseases, it has proven to be ineffective, with controversial consequences for the environment, human health and the balance of edaphic microbiota (Andrés et al, 2016). An alternative has emerged to address these limitations by using biocontrol as part of sustainable crop management in order to improve productivity by increasing the availability of nutrients and phytopathogen protection (Sherathia et al, 2016). The products used for biological control are preparations of living or latent cells of microorganisms that, when applied to the soil or seed, favor the plant-rhizosphere relationship (Bashan et al, 2013).…”