Genetic diversity of groundnut rhizosphere antagonistic bacteria and biological control of groundnut wilted diseases in central Vietnam

2018 ◽  
Author(s):  
C. N. Le ◽  
T. H. Thai ◽  
D. H. Tran ◽  
T. L. Nguyen ◽  
T.T. H. La ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Biological Control ◽  
Disease Control ◽  
Bacterial Strain ◽  
Bacterial Population ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Bacterial Strains ◽  
Central Vietnam

Stem rot of groundnut caused by Sclerotium rolfsii, seriously damages groundnut production in central Vietnam. Biological control is a promising strategy for sustainable groundnut cultivation. In this study, indigenous bacteria were isolated from the rhizosphere of groundnut and tested for fungal inhibition against S. rolfsii in vitro and disease control under net house condition. Genetic diversity of isolated bacterial population was evaluated by BOX-PCR and 16S rDNA sequences. Bacterial strains that showed high disease control in net house were evaluated under natural conditions in farmer fields. The antifungal mechanism of the best bacterial strain was identified. Results of the study showed that the antagonistic bacterial population in groundnut rhizosphere is separated in three bacterial genera including Bacillus, Pseudomonas and Burkholderia. One bacterial strain which produces 2,4-DAPG reduced stem rot of groundnut caused by S. rolfsii and increased yield from 20.3 to 26.3% compared to the control.

scholarly journals Production of lytic enzymes by Trichoderma strains during in vitro antagonism with Sclerotium rolfsii, the causal agent of stem rot of groundnut

2015 ◽  
Vol 9 (6) ◽  
pp. 365-372 ◽  
Author(s):  
J Parmar H ◽  
P Bodar N ◽  
N Lakhani H ◽  
V Patel S ◽  
V Umrania V ◽  
...  
Keyword(s):  
Sclerotium Rolfsii ◽  
Causal Agent ◽  
Stem Rot ◽  
Lytic Enzymes

Biological Control of Stem Rot of Pepper caused by Sclerotium rolfsii using by Bacillus amyloliquefaciens KBC1009

2016 ◽  
Vol 50 (4) ◽  
pp. 27-34
Author(s):  
Jae-Gon Kang ◽  
◽  
Young-Ui Lee ◽  
Jeong-chan Park ◽  
Yoon-Woo Jeong ◽  
...  
Keyword(s):  
Biological Control ◽  
Bacillus Amyloliquefaciens ◽  
Sclerotium Rolfsii ◽  
Stem Rot

Composts containing fluorescent pseudomonads suppress fusarium root and stem rot development on greenhouse cucumber

2010 ◽  
Vol 56 (11) ◽  
pp. 896-905 ◽  
Author(s):  
Geoffrey G. Bradley ◽  
Zamir K. Punja
Keyword(s):  
Disease Severity ◽  
Total Population ◽  
Fusarium Species ◽  
Severity Index ◽  
Stem Rot ◽  
Bacterial Strains ◽  
Growth Room ◽  
Greenhouse Cucumber ◽  
Layer Chromatography

Three composts (Ball, dairy, and greenhouse) were tested for the ability to suppress the development of Fusarium root and stem rot (caused by Fusarium oxysporum f. sp. radicis-cucumerinum) on greenhouse cucumber. Dairy and greenhouse composts significantly reduced disease severity (P = 0.05), while Ball compost had no effect. Assessment of total culturable microbes in the composts showed a positive relationship between disease suppressive ability and total population levels of pseudomonads. In vitro antagonism assays between compost-isolated bacterial strains and the pathogen showed that strains of Pseudomonas aeruginosa exhibited the greatest antagonism. In growth room trials, strains of P. aeruginosa and nonantagonistic Pseudomonas maculicola , plus 2 biocontrol strains of Pseudomonas fluorescens , were tested for their ability to reduce (i) survival of F. oxysporum, (ii) colonization of plants by the pathogen, and (iii) disease severity. Cucumber seedlings grown in compost receiving P. aeruginosa and P. fluorescens had reduced disease severity index scores after 8 weeks compared with control plants without bacteria. Internal stem colonization by F. oxysporum was significantly reduced by P. aeruginosa. The bacteria colonized plant roots at 1.9 × 106 ± 0.73 × 106CFU·(g root tissue)–1and survival was >107 CFU·(g compost)–1after 6 weeks. The locus for 2,4-diacetylphloroglucinol production was detected by Southern blot analysis and confirmed by PCR. The production of the antibiotic 2,4-diacetylphloroglucinol in liquid culture by P. aeruginosa was confirmed by thin layer chromatography. These results demonstrate that composts containing antibiotic-producing P. aeruginosa have the potential to suppress diseases caused by Fusarium species.

Evaluation of Ammonium Bicarbonate for Control of Soilborne Peanut Pathogens

1990 ◽  
Vol 17 (1) ◽  
pp. 28-31 ◽  
Author(s):  
T. B. Brenneman ◽  
A. S. Csinos ◽  
P. M. Phipps
Keyword(s):  
Rhizoctonia Solani ◽  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Foliar Spray ◽  
Ammonium Bicarbonate ◽  
In Vitro Studies ◽  
Stem Rot ◽  
Pod Yield ◽  
Sclerotinia Blight

Abstract Ammonium bicarbonate was evaluated for efficacy against southern stem rot and Sclerotinia blight of peanut in Georgia and Virginia, respectively. In vitro studies indicated the material provided little inhibition of mycelial growth by Sclerotinia minor and Sclerotium rolfsii, and negligible inhibition of mycelial growth of Rhizoctonia solani AG-4. However, ammonium bicarbonate did effectively inhibit formation of sclerotia by S. rolfsii in vitro. In the field, it was phytotoxic when applied as a granule or as a foliar spray and in general was not effective in controlling disease or increasing pod yield.

scholarly journals VARIAN SOMAKLONAL KACANG TANAH RESISTEN SCLEROTIUM ROLFSII HASIL SELEKSI IN VITRO MENGGUNAKAN FILTRAT KULTUR CENDAWAN

2010 ◽  
Vol 10 (1) ◽  
pp. 35-46
Author(s):  
Yusnita Yusnita ◽  
Hajrial Aswidinnoor ◽  
Rita Megia ◽  
Rusmilah Suseno ◽  
Sudarsono Sudarsono
Keyword(s):  
In Vitro Selection ◽  
Healing Process ◽  
Sclerotium Rolfsii ◽  
Selective Medium ◽  
Stem Rot ◽  
Wound Healing Process ◽  
Fungal Culture ◽  
Somaclonal Variants ◽  
Culture Filtrates

Peanut somaclonal variants resistant to Sclerotium rolfsii derived from in vitro selection with fungal culture filtrates. Sclerotium stem rot is one of the most important peanut disease which often caused significant yield loss.  The use of peanut cultivars resistant to Sclerotium rolfsii infection is the most efficient way to control the disease.  Attempts to obtain peanut lines with tolerance or resistance to Sclerotium stem rot through induction of somaclonal variation and in vitro selection using fungal culture filtrates (CF) have been conducted previously. Somatic embryo (SE) clumps that had been maitained in culture for approximately one year in regeneration medium were exposed onto selective medium containing 30% S. rolfsii CF for three consecutive 1 month –passages, and the SE formed after selection periods were considered to be insensitive to the fungal CF. A number R0 peanut lines have been regenerated from CF-insensitive SE, and their R1 and R2 progenies were grown in a plastic house for evaluation on qualitative and quantitative variant characters.  Early identification for tolerance to S. rolfsii was also conducted among R0 peanut lines, and the results have shown enhanced resistance when compared to the original non-selected cultivar.  However, further evaluation is needed to study responses of the R1 and R2 progenies of the somaclones against S. rolfsii infection.  The objective of this particular study was to evaluate responses of R1 and R2 peanut somaclones derived from fungal CF-insensitif SE against S. rolfsii infection in the plastic house.  Results of this experiment showed, a number of resistant somaclonal variants were obtained among R1 and R2 population, which segregated as resistance and susceptible to S. rolfsii infection.  The resistance somaclonal variants initially showed stem rot symptoms after inoculation with S. rolfsii with disease score (DS) of 1 to 3.  However, as the plants grew and developed, they showed wound-healing process at the lesio and they were able to produce the same or higher number of filled pod as the original non-inoculated peanut plants.

scholarly journals Isolation of Endophytic Fungi from Vitex trifolia L and Antagonism Test against Sclerotium rolfsii and pathogenic bacteria

2021 ◽  
Vol 21 (1) ◽  
pp. 72
Author(s):  
Muhammad Hasan Basri ◽  
Lalu Zulkifli ◽  
Abdul Syukur
Keyword(s):  
Biological Control ◽  
Endophytic Fungi ◽  
Pathogenic Bacteria ◽  
Pathogenic Fungus ◽  
Sclerotium Rolfsii ◽  
Pathogenic Fungi ◽  
Promising Alternative ◽  
Environmental Friendly ◽  
Low Activity

Plant damage by pathogenic fungi is often found in plants, one of which is caused by Sclerotium rolfsii. Biological control strategy offers a promising alternative for managing disease in plants because they are environmental friendly compared to pesticides application. One of the biological control offered is by using endophytic fungi isolated from Vitex trivolia L. The aim of the study was to isolate, to identify macroscopic and microscopic endophytic fungi from Vitex trifolia L and to test their antagonism potency against the pathogenic fungus Sclerotium rolfsii in vitro. The isolation obtained 7 endophytic fungi isolates identified based on their genus characteristics, nsmely Periconia sp, Aspergillussp, Dendrophoma  sp, Geotrichum  sp, Ampulliferina  sp, Chalara  sp, dan Bispora sp and 2 isolates have not been identified. The Antibacterial test of the fungi isolate on the 4 tested bacteria showed that of all the fungi isolate have low activity. The antagonism test using the direct opposition method with the PIRG formula, showed that the 3 isolates had high percentage of growth inhibition, in which ALJ1, BLJ5, and ALJ3 isolate has  85%, 90%, and 100% respectively. This potency could be used as biological agents on the pathogenic fungus Sclerotium rolfsii.

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