Rice-associated antagonistic bacteria suppress the Fusarium fujikoroi causing rice bakanae disease

BioControl ◽  
2021 ◽  
Author(s):  
Mah-E-Neema Nawaz ◽  
Kamran Malik ◽  
Muhammad Nadeem Hassan
Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 209
Author(s):  
Nadia Lyousfi ◽  
Rachid Lahlali ◽  
Chaimaa Letrib ◽  
Zineb Belabess ◽  
Rachida Ouaabou ◽  
...  

The main objective of this study was to evaluate the ability of both antagonistic bacteria Bacillus amyloliquefaciens (SF14) and Alcaligenes faecalis (ACBC1) used in combination with salicylic acid (SA) to effectively control brown rot disease caused by Monilinia fructigena. Four concentrations of salicylic acid (0.5%, 2%, 3.5%, and 5%) were tested under in vitro and in vivo conditions. Furthermore, the impact of biological treatments on nectarine fruit parameters’ quality, in particular, weight loss, titratable acidity, and soluble solids content, was evaluated. Regardless of the bacterium, the results indicated that all combined treatments displayed a strong inhibitory effect on the mycelial growth of M. fructigena and disease severity. Interestingly, all SA concentrations significantly improved the biocontrol activity of each antagonist. The mycelial growth inhibition rate ranged from 9.79% to 88.02% with the highest reduction rate recorded for bacterial antagonists in combination with SA at both concentrations of 0.5% and 3.5%. The in vivo results confirmed the in vitro results with a disease severity varying from 0.00% to 51.91%. A significant biocontrol improvement was obtained with both antagonistic bacteria when used in combination with SA at concentrations of 0.5% and 2%. The lowest disease severity observed with ACBC1 compared with SF14 is likely due to a rapid adaptation and increase of antagonistic bacteria population in wounded sites. The impact of all biological treatments revealed moderate significant changes in the fruit quality parameters with weight loss for several treatments. These results suggest that the improved disease control of both antagonistic bacteria was more likely directly linked to both the inhibitory effects of SA on pathogen growth and induced fruit resistance.


1994 ◽  
Vol 1994 (40) ◽  
pp. 33-37 ◽  
Author(s):  
Takumi YOSHIZAWA ◽  
Mika YAMASAKI ◽  
Naoki NANBA ◽  
Akihiro YAMASHITA ◽  
Susumu UEDA ◽  
...  

2021 ◽  
pp. 103622
Author(s):  
Edoardo Piombo ◽  
Marco Rosati ◽  
Martina Sanna ◽  
Monica Mezzalama ◽  
M. Lodovica Gullino ◽  
...  

2006 ◽  
Vol 96 (12) ◽  
pp. 1372-1379 ◽  
Author(s):  
Masahiro Kasuya ◽  
Andriantsoa R. Olivier ◽  
Yoko Ota ◽  
Motoaki Tojo ◽  
Hitoshi Honjo ◽  
...  

Suppressive effects of soil amendment with residues of 12 cultivars of Brassica rapa on damping-off of sugar beet were evaluated in soils infested with Rhizoctonia solani. Residues of clover and peanut were tested as noncruciferous controls. The incidence of damping-off was significantly and consistently suppressed in the soils amended with residues of clover, peanut, and B. rapa subsp. rapifera ‘Saori’, but only the volatile substance produced from water-imbibed residue of cv. Saori exhibited a distinct inhibitory effect on mycelial growth of R. solani. Nonetheless, disease suppression in such residue-amended soils was diminished or nullified when antibacterial antibiotics were applied to the soils, suggesting that proliferation of antagonistic bacteria resident to the soils were responsible for disease suppression. When the seed (pericarps) colonized by R. solani in the infested soil without residues were replanted into the soils amended with such residues, damping-off was suppressed in all cases. In contrast, when seed that had been colonized by microorganisms in the soils containing the residues were replanted into the infested soil, damping-off was not suppressed. The evidence indicates that the laimosphere, but not the spermosphere, is the site for the antagonistic microbial interaction, which is the chief principle of soil suppressiveness against Rhizoctonia damping-off.


Plant Disease ◽  
2021 ◽  
Author(s):  
Yang Bai ◽  
Chun-Yan Gu ◽  
Rui Pan ◽  
Muhammad Abid ◽  
Hao-Yu Zang ◽  
...  

New fungicides are tools to manage fungal diseases and overcome emerging resistance in fugnal pathogens. In this study, a total of 121 isolates of Fusarium fujikuroi, the causal agent of rice bakanae disease (RBD), were collected from various geographical regions of China, and their sensitivity to a novel succinate dehydrogenase inhibitor (SDHI)fungicide ‘pydiflumetofen’ was evaluated. The 50% effective concentration (EC50) value of pydiflumetofen for mycelial growth suppression ranged from 0.0101 to 0.1012 μg/ml and for conidial germination inhibition ranged from 0.0051to 0.1082 μg/ml. Pydiflumetofen treated hyphae showed contortion and increased branching, cell membrane permeability, and glycerol content significantly. The result of electron microscope transmission indicated that pydiflumetofen damaged the mycelial cell wall and the cell membrane, and almost broken up the cells, which increased the intracellular plasma leakage. There was no cross-resistance between pydiflumetofen and the widely used fungicides such as carbendazim, prochloraz, and phenamacril. Pydiflumetofen was found safe to seeds and rice seedlings of four rice cultivars, used up to 400 μg/ml. Seed treatment significantly decreased the rate of diseased plants in the greenhouse as well as in field trials in 2017 and 2018. Pydiflumetofen showed superb results against RBD, when used at 10 or 20 g a.i./100 kg of treated seeds, providing over 90% control efficacy (the highest control efficacy was up to 97%), which was significantly higher than that of 25% phenamacril (SC) at 10g or carbendazim at 100 g. Pydiflumetofen is highly effective against F. fujikuroi growth and sporulation as well as RBD in the field.


2018 ◽  
Vol 85 (1) ◽  
Author(s):  
Haruhisa Suga ◽  
Mitsuhiro Arai ◽  
Emi Fukasawa ◽  
Keiichi Motohashi ◽  
Hiroyuki Nakagawa ◽  
...  

ABSTRACTFusarium fujikuroiis a pathogenic fungus that infects rice. It produces several important mycotoxins, such as fumonisins. Fumonisin production has been detected in strains of maize, strawberry, and wheat, whereas it has not been detected in strains from rice seedlings infested with bakanae disease in Japan. We investigated the genetic relationships, pathogenicity, and resistance to a fungicide, thiophanate-methyl (TM), in 51 fumonisin-producing strains and 44 nonproducing strains. Phylogenetic analyses based on amplified fragment length polymorphism (AFLP) markers and two specific genes (a combined sequence of translation elongation factor 1α [TEF1α] and RNA polymerase II second-largest subunit [RPB2]) indicated differential clustering between the fumonisin-producing and -nonproducing strains. One of the AFLP markers, EATMCAY107, was specifically present in the fumonisin-producing strains. A specific single nucleotide polymorphism (SNP) between the fumonisin-producing and nonproducing strains was also detected inRPB2, in addition to an SNP previously found inTEF1α. Gibberellin production was higher in the nonproducing than in the producing strains according to anin vitroassay, and the nonproducing strains had the strongest pathogenicity with regard to rice seedlings. TM resistance was closely correlated with the cluster of fumonisin-nonproducing strains. The results indicate that intraspecific evolution in JapaneseF. fujikuroiis associated with fumonisin production and pathogenicity. Two subgroups of JapaneseF. fujikuroi, designated G group and F group, were distinguished based on phylogenetic differences and the high production of gibberellin and fumonisin, respectively.IMPORTANCEFusarium fujikuroiis a pathogenic fungus that causes rice bakanae disease. Historically, this pathogen has been known asFusarium moniliforme, along with many other species based on a broad species concept. Gibberellin, which is currently known as a plant hormone, is a virulence factor ofF. fujikuroi. Fumonisin is a carcinogenic mycotoxin posing a serious threat to food and feed safety. Although it has been confirmed thatF. fujikuroiproduces gibberellin and fumonisin, production varies among strains, and individual production has been obscured by the traditional appellation ofF. moniliforme, difficulties in species identification, and variation in the assays used to determine the production of these secondary metabolites. In this study, we discovered two phylogenetic subgroups associated with fumonisin and gibberellin production in JapaneseF. fujikuroi.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
M. M. Rahman ◽  
M. E. Ali ◽  
A. A. Khan ◽  
A. M. Akanda ◽  
Md. Kamal Uddin ◽  
...  

A total of 91 isolates of probable antagonistic bacteria of potato soft rot bacteriumErwinia carotovorasubsp.carotovora(Ecc) were extracted from rhizospheres and endophytes of various crop plants, different soil varieties, and atmospheres in the potato farming areas of Bangladesh. Antibacterial activity of the isolated probable antagonistic bacteria was testedin vitroagainst the previously identified most common and most virulent soft rot causing bacterial strain Ecc P-138. Only two isolates E-45 and E-65 significantly inhibited thein vitrogrowth of Ecc P-138. Physiological, biochemical, and carbon source utilization tests identified isolate E-65 as a member of the genusBacillusand the isolate E-45 asLactobacillussp. The stronger antagonistic activity against Ecc P-138 was found in E-65in vitroscreening and storage potatoes. E-65 reduced the soft rot infection to 22-week storage potatoes of different varieties by 32.5–62.5% in model experiment, demonstrating its strong potential to be used as an effective biological control agent for the major pectolytic bacteria Ecc. The highest (62.5%) antagonistic effect of E-65 was observed in the Granola and the lowest (32.7%) of that was found in the Cardinal varieties of the Bangladeshi potatoes. The findings suggest that isolate E-65 could be exploited as a biocontrol agent for potato tubers.


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