Plant Growth-Promoting Rhizobacteria (PGPR): An Indispensable Tool for Climate-Resilient Crop Production (original) (raw)
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Systemic induction of defense response in plants can be obtained by treatment with different microorganisms. Present study was aimed to investigate the effect of two strains of Bacillus viz Bacillus fortis 162 and Bacillus subtilus 174 for induction of systemic resistance in tomato against Fusarium wilt disease under lab conditions. For this purpose roots of tomato seedlings were primed with Bacillus strains and plants were challenged with pathogen. Biocontrol potential of test strains of Bacillus was studied along with quantification of total phenolic compounds and defense related proteins viz. Polyphenol Oxidase (PPO), Phenyl Ammonia Lyase (PAL) and Peroxidase (PO) by Calometric methods. B. subtilus 174 showed great biocontrol potential and significant reduction in disease severity. Higher levels of phenolic compounds, PPO, PAL and PO activities were observed in case of B. subtilus 174 in shoots of tomato plants as compared to B. fortis 162. This bacterial strain can be used as a biocontrol agent for sustainable management of Fusarium wilt of tomato.
MODE OF ACTION OF BACILLUS SUBTILIS EPCO16 AGAINST TOMATO FUSARIUM WILT
Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici has been known to cause severe yield losses in tomato. Hence, attempts were made to develop an effective ecofriendly strategy to manage the disease using endophytic and plant growth promoting rhizobacteria. Accordingly, the strains of Bacillus subtilis was tested for its effectiveness against tomato Fusarium wilt under in vitro. Under in vitro conditions B. subtilis EPCO16 was found to effectively inhibit the mycelial growth of the pathogen (46.04%) and promote the growth of tomato seedlings (vigour index: 2311.46) when compared to control. Further, B. subtilis EPCO16 produced a large orange halo in Chrome Azurol Sulphonate (CAS) agar plate assay and the nature of siderophore was Hydroxymate type. The same strain was found to be positive for hydrogen cyanide production and produced volatile compound which effectively inhibited the growth of F. oxysporum f. sp. lycopersici to an extent of 60.78 per cent in vitro. B. subtilis EPCO16 is positive for chitinase, β β β β β-1,3-glucanase and Proteolytic enzyme activity. These findings suggest that B. subtilis EPCO16 can be successfully employed as an eco-friendly strategy for the management of Fusarium wilt of tomato.
Bragantia, 2014
Fusarium wilt, caused by Fusarium oxysporum f.sp. lycopersici (Fol), is one of the most important diseases that affect tomato yield worldwide. This study investigated the potential of three antagonists, Streptomyces setonii (UFV 618), Bacillus cereus (UFV 592) and Serratia marcescens (UFV 252), and as positive control the hormone jasmonic acid (JA), to reduce Fusarium wilt symptoms and to potentiate the defense enzymes in the stem tissues of tomato plants infected by Fol. The seeds were microbiolized with each antagonist, and the soil was also drenched with them. The plants were sprayed with JA 48 h before Fol inoculation. The area under the Fusarium wilt index progress curve was reduced by 54, 48, 47 and 45% for the UFV 618, JA, UFV 592 and UFV 252 treatments, respectively. The three antagonists, and even the JA spray, efficiently reduced the Fusarium wilt symptoms on the tomato plant stems, which can be explained by the lower malondialdehyde concentration (an indication of oxidati...
The biocontrol agent Bacillus subtilis EPCO16 is studied as an effective endophytic biocontrol agent in the management of plant diseases besides promoting plant growth. The efficacy of B. subtilis EPCO16 was tested for the induction of systemic resistance against tomato Fusarium wilt. B. subtilis EPCO16 in liquid and talc formulation on the induction of proteins and defense enzymes viz., phenylalanine ammonia lyase, catalase and phenolics in tomato plants infected with Fusarium oxysporum f. sp. lycopersici was studied under glass house condition. Activities of these enzymes increased in seed treatment, seedling dip and soil application of EPCO16 in liquid formulation on tomato plants challenged with the pathogen. The defense related proteins viz. phenylalanine ammonia lyase (PAL), catalase and phenolics were analysed spectrophotometrically. Activities of these enzymes reached maximum at the 7th day after challenge inoculation. The present study has helped in identifying an isolate B. subtilis EPCO16 with higher ability to induce defense related compounds in tomato plants against F. oxysporum f. sp. lycopersici.
Acta Horticulturae, 2018
Fusarium oxysporum f. sp. radicis-lycopersici (Forl) is the causal agent of fusarium crown and root rot of tomato, a devastating disease causing extensive yield losses. Plant-growth-promoting rhizobacteria (PGPR) can be potential agents for biological control of plant pathogens. Among them, strains of Bacillus subtilis are well known for their ability to control foliar and soil-borne pathogens. In this study, we investigated the effects of a new Bacillus amyloliquefaciens strain (ΜΒΙ 600) on the growth of tomato and the control of Forl under both in-vitro and in-planta conditions. In the in-vitro experiments, the biological control agent reduced mycelial growth of Forl by 24.1%, while it also showed a weak antagonistic activity (antibiosis-inhibition zone <10mm). Dual applications of B. amyloliquefaciens MBI 600 on tomato seeds before sowing and on young seedlings before transplanting induced significant (P<0.05) increases in shoot height and root length. Similarly, dual applications of B. amyloliquefaciens MBI 600 resulted in significant (P<0.05) reductions in both disease severity and disease index (%), by 75% compared with untreated control plants.
Revista Colombiana de Biotecnología
Use of biotechnological potential of native microorganisms as bio-inputs is having a great impact on agricultural systems. Plant Growth Promoting Rhizobacteria (PGPR), in addition to their beneficial effect on plant growth and on the availability of soil elements, also have an antagonistic effect against different pathogens. In this study, growth promotion mechanisms with emphasis on the antagonism of PGPR isolated from sugarcane and tomato crops were evaluated. Antagonism against Fusarium oxysporum f.sp lycopersici (Fol) was determined by dual tests, inhibition of germination and production of chitinases and endoglucanases. 52 isolates were evaluated and according to their results in dual tests 10 were selected for further analysis. Isolate GIBI127 showed the best percentage of Inhibition Germination (IG) of Fol (59.29%). Then, a selection index was calculated using results from gi, dual tests and growth promotion mechanisms to select five best isolates. Finally, these bacteria wer...
2018
An alternative in organic agriculture is the use of biofertilizers base rhizobacteria promoting plant growth and organic fertilizers “plant growth promoting rhizobacteria (PGPR) by its acronym in English”. The objective of the present work was to evaluate the effect of the inoculation of PGPR (Bacillus sp., Aeromonas sp. and Pseudomonas lini), using two substrates: S1= compost + river sand + perlite, and S2= river sand and as witnesses both substrates without PGPR (total of eight treatments), on the yield and quality of tomato fruits produced in the greenhouse. The experimental design used was completely randomized with three repetitions in a factorial arrangement (2 × 4), where factors A and B were: a) substrates and b) PGPR. The results indicate that the substrate S1 increased the contents of SST, lycopene, total sugars, ascorbic acid and the percentage of citric acid in tomato fruits. The inoculation of the strain Bacillus sp., Produced the highest contents of SST, lycopene and a...