scholarly journals In-vitro Evaluation of Actinobacteria for its Potential in Bio-control of Fungal Plant Pathogens

2019 ◽  
Vol 7 (1) ◽  
pp. 82-87
Author(s):  
Zothan puia ◽  
◽  
W. Carrie ◽  
V.V. Leo ◽  
A.K. Passari ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Control Strategies ◽  
Dual Culture ◽  
Inhibition Activity ◽  
Fungal Plant Pathogens ◽  
Basic Understanding ◽  
Dual Culture Assay ◽  
Antagonistic Potential ◽  
Fungal Phytopathogens

Infections caused by fungal plant pathogens are recently recognized as a threat to food security worldwide and its control strategies need to be taken care where naturally synthesized fungicides such as those obtained from actinobacteria are becoming an area of great interest. A total of 68 isolates of actinobacteria were evaluated for their antagonistic potential against four fungal plant pathogens viz., Fusarium oxysporum CABI-293942, Fusarium udum MTCC-2755, Fusarium proliferatum MTCC-286 and Fusarium graminearum MTCC-1893 by dual culture assay. It was found that 83.8% of the isolates showed inhibitory activity against at least one of the tested plant pathogens with the percentage of inhibition ranging from 20–87.2. Thirteen Streptomyces isolates and one Nocardiposis isolate exhibited inhibition activity against all the tested pathogens. Overall, this study gives a basic understanding of the potential aspect of freshwater sediments derived actinobacteria against fungal phytopathogens.

scholarly journals Evaluation of in-vitro methods to select effective streptomycetes against toxigenic fusaria

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6905 ◽  
Author(s):  
Elena Maria Colombo ◽  
Cristina Pizzatti ◽  
Andrea Kunova ◽  
Claudio Gardana ◽  
Marco Saracchi ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Culture Media ◽  
Screening Methods ◽  
Dual Culture ◽  
In Planta ◽  
In Vitro Method ◽  
In Vitro Methods ◽  
Strain Diversity ◽  
Fungal Plant Pathogens

Biocontrol microorganisms are emerging as an effective alternative to pesticides. Ideally, biocontrol agents (BCAs) for the control of fungal plant pathogens should be selected by an in vitro method that is high-throughput and is predictive of in planta efficacy, possibly considering environmental factors, and the natural diversity of the pathogen. The purpose of our study was (1) to assess the effects ofFusariumstrain diversity (N= 5) and culture media (N= 6) on the identification of biological control activity ofStreptomycesstrains (N= 20) againstFusariumpathogens of wheat in vitro and (2) to verify the ability of our in vitro screening methods to simulate the activity in planta. Our results indicate that culture media,Fusariumstrain diversity, and their interactions affect the results of an in vitro selection by dual culture assay. The results obtained on the wheat-based culture media resulted in the highest correlation score (r= 0.5) with the in planta root rot (RR) inhibition, suggesting that this in vitro method was the best predictor of in planta performance of streptomycetes against Fusarium RR of wheat assessed as extension of the necrosis on the root. Contrarily, none of the in vitro plate assays using the media tested could appropriately predict the activity of the streptomycetes against Fusarium foot rot symptoms estimated as the necrosis at the crown level. Considering overall data of correlation, the activity in planta cannot be effectively predicted by dual culture plate studies, therefore improved in vitro methods are needed to better mimic the activity of biocontrol strains in natural conditions. This work contributes to setting up laboratory standards for preliminary screening assays ofStreptomycesBCAs against fungal pathogens.

scholarly journals Biological Control Potential of Streptomyces sp. AR10 Producing Albocycline Isolated from Soil around Ant Nest

2018 ◽  
Vol 10 (3) ◽  
pp. 54
Author(s):  
Tatsuya Ohike ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
Takashi Ano
Keyword(s):  
Biological Control ◽  
Plant Pathogens ◽  
Sequence Similarity ◽  
Antifungal Compound ◽  
Dual Culture ◽  
High Sequence Similarity ◽  
Genus Streptomyces ◽  
Fungal Plant Pathogens ◽  
Biological Control Potential ◽  
Dual Culture Assay

Fifty actinomycetes were isolated from fifteen soil samples and were screened for their antagonism against fungal plant pathogens by dual culture assay, and one of the strain named AR10 was shown to be most effective in suppression of growth of plant pathogen. An antifungal compound of AR10 was extracted, and purified by TLC and HPLC. As a result of NMR and LC-MS analysis, the antifungal compound was identified as albocycline. AR10 suppressed Rhizoctonia damping-off of cucumber in infection control assay. The 16S rDNA sequence of AR10 shows high sequence similarity to those of genus Streptomyces, and the closest similarity was found in the sequence of S. lanatus NBRC 12787T with 98.7% similarity. However, the production of albocycline in Streptomyces closely related to AR10 in the phylogenetic tree has not been reported. Our finding suggests that AR10 can be a candidate for biological control agents.

scholarly journals Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens

2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Yan Ramona ◽  
IDA BAGUS GEDE DARMAYASA ◽  
ANAK AGUNG NGURAH NARA KUSUMA ◽  
Martin Line
Keyword(s):  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Antagonistic Activity ◽  
Significant Inhibition ◽  
Biocontrol Agents ◽  
Dual Culture ◽  
Rdna Sequences ◽  
Fungal Plant Pathogens ◽  
Mature Compost

Abstract. Ramona Y, Darmayasa IBG, Kusuma AANN, Line MA. 2021. Diversity of biocontrol agents, isolated from several sources, inhibitory to several fungal plant pathogens. Biodiversitas 22: 298-303. This study investigated the inhibitory potential of diversity of antagonist bacteria residing in the rhizosphere zone and mature compost to counter fungal plant pathogens. Soils collected from rhizosphere of lettuce farms in Bali-Indonesia and Tasmania-Australia, mature compost, commercial biocontrol (Dipel®), and laboratory contaminants with significant inhibition against tested fungal pathogens were used as sources of antagonist bacteria. These antagonists were isolated by applying dilution and spread method on trypticase soya agar (TSA) or potato dextrose agar (PDA), and their ability to inhibit Sclerotinia minor, Sclerotinia sclerotiorum, Fusarium spp., and Rhizoctonia solani was assessed in dual culture assays. The results showed that 67 out of more than 100 isolates had antagonistic activity in vitro against at least one of tested fungal pathogens. In the preliminary identification, Bacillus spp. or Pseudomonas spp. were found to be pre-dominant isolates. Following screening studies in a non-replicated glasshouse experiment against S. minor and S. sclerotiorum, 8 of the most promising isolates were further identified using molecular methods based on their 16s rDNA sequences aligned with those deposited at the GeneBank. These 8 isolates were identified as Pseudomonas corrugata, Bacillus megaterium, Bacillus polymyxa, Bacillus mojavensis, Bacillus pumilus, Bacillus thuringiensis, Exiguobacterium acetylicum, and Chryseobacterium indologenes.

scholarly journals In vitro antagonistic activity of Trichoderma harzianum and T. viride strains compared to carbendazim fungicide against the fungal phytopathogens of Sorghum bicolor (L.) Moench

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Mohamed Taha Yassin ◽  
Ashraf Abdel-Fattah Mostafa ◽  
Abdulaziz Abdulrahman Al-Askar
Keyword(s):  
Ethyl Acetate ◽  
Mycelial Growth ◽  
Fungal Diseases ◽  
Diffusion Method ◽  
Dual Culture ◽  
Fungal Strains ◽  
Dual Culture Assay ◽  
Fungal Phytopathogens ◽  
Ethyl Acetate Extracts

Abstract Background High losses of sorghum crops due to fungal diseases, such as grain mold and stalk rot, are economically harmful and cause increased use of environmentally damaging chemical fungicides, which also are detrimental to human health. Hence, finding safe and effective ways to manage fungal diseases of sorghum is urgently needed. Results In the present study, the antagonistic activities of Trichoderma viride and T. harzianum against different pathogenic fungal strains were evaluated in vitro using a dual culture assay. Furthermore, the anti-mycotic activity of Trichoderma spp. culture filtrates was evaluated against different fungal strains using a food poisoning technique. Additionally, the antifungal activities of ethyl acetate extracts of T. viride and T. harzianum against different pathogens were evaluated using a disk diffusion method. As indicated by the dual culture assay, T. harzianum suppressed 66.8, 69.5, 68.7, 54.6, 84.12, and 71.39% of the mycelial growth of Curvularia lunata, Exserohilum rostratum, Fusarium chlamydosporum, F. incarnatum, F. proliferatum, and Macrophomina phaseolina, respectively. T. viride was more effective for controlling the growth of these pathogens, inhibiting 81.0, 89.0, 63.0, 70.7, 84.4, and 71.8% of mycelial growth, respectively. Both E. rostratum and M. phaseolina showed resistance to carbendazim fungicide at all tested concentrations, whereas the fungicidal concentrations of carbendazim against C. lunata, F. chlamydosporum, and F. incarnatum strains were 2.50, 1.50, and 2.00 ppm, respectively. Furthermore, F. proliferatum was sensitive to carbendazim fungicide at all tested concentrations. Antifungal assays of the ethyl acetate extracts of T. viride and T. harzianum indicated the potent activity of these extracts against fungal phytopathogens with different susceptibility patterns. F. chlamydosporum was the most sensitive to the extracts of T. viride and T. harzianum with minimum inhibitory concentrations of 0.5 and 1.0 mg/disk, respectively. Conclusion The potent suppression of sorghum phytopathogens by T. viride and T. harzianum makes them potential sources of safe and effective natural fungicides compared to carbendazim fungicide.

scholarly journals In vitro and in vivo Assay for Assessment of the Biological Control Potential of Streptomyces sp. KT

2017 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Tatsuya Ohike ◽  
Minori Maeda ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
...  
Keyword(s):  
Biological Control ◽  
Suppressive Effect ◽  
Phytopathogenic Fungi ◽  
Dual Culture ◽  
Biological Control Agents ◽  
Bipolaris Oryzae ◽  
Biological Control Potential ◽  
Dual Culture Assay

Rhizoctonia solani is fungal plant pathogen that infects many different host plants. Recently, biological control agents that are friendly to the environment and ecosystems have attracted much attention as an alternative to the use of chemical fungicide which have been used worldwide to control soil borne pathogens including R. solani. In this study, 53 strains of actinomycetes isolated from environmental soils, and antifungal activities of them were assessed by the dual culture assay. Strain KT showed strong inhibitory activities against 8 phytopathogenic fungi. A great suppressive effect on R. solani growth was observed in the inoculation test of plants using cucumber and chin-geng-sai. In addition, infection of Bipolaris oryzae also could be suppressed in the detached leaf assay using oats. As a result of genetic analysis, it was shown that KT was a species closely related to Streptomyces lavenduligriseus NRRL B-3173T. However, as far as we know, there is no report for biological control agents using S. lavenduligriseus. This study suggests that the strain KT may useful as biological control agents to suppress various crop diseases.

scholarly journals Plant Defensin Peptides have Antifungal and Antibacterial Activity Against Human and Plant Pathogens

2019 ◽  
Vol 109 (3) ◽  
pp. 402-408 ◽  
Author(s):  
Andrew E. Sathoff ◽  
Siva Velivelli ◽  
Dilip M. Shah ◽  
Deborah A. Samac
Keyword(s):  
Antibacterial Activity ◽  
Plant Pathogens ◽  
Crown Rot ◽  
Plant Defensin ◽  
Core Motif ◽  
Potential Control ◽  
Fungal Plant Pathogens ◽  
Plant Defensins ◽  
Animal Pathogens

Plant defensins are small, cysteine-rich antimicrobial peptides. These peptides have previously been shown to primarily inhibit the growth of fungal plant pathogens. Plant defensins have a γ-core motif, defined as GXCX3-9C, which is required for their antifungal activity. To evaluate plant defensins as a potential control for a problematic agricultural disease (alfalfa crown rot), short, chemically synthesized peptides containing γ-core motif sequences were screened for activity against numerous crown rot pathogens. These peptides showed both antifungal and, surprisingly, antibacterial activity. Core motif peptides from Medicago truncatula defensins (MtDef4 and MtDef5) displayed high activity against both plant and human bacterial pathogens in vitro. Full-length defensins had higher antimicrobial activity compared with the peptides containing their predictive γ-core motifs. These results show the future promise for controlling a wide array of economically important fungal and bacterial plant pathogens through the transgenic expression of a plant defensin. They also suggest that plant defensins may be an untapped reservoir for development of therapeutic compounds for combating human and animal pathogens.

scholarly journals In-vitro Evaluation of Bio-control agents against Soil Borne Plant Pathogens

2019 ◽  
Vol 5 ◽  
pp. 68-72
Author(s):  
Shrinkhala Manandhar ◽  
Bimala Pant ◽  
Chetana Manandhar ◽  
Suraj Baidya
Keyword(s):  
Plant Pathogens ◽  
Field Experiments ◽  
Colony Growth ◽  
Dual Culture ◽  
Vitro Assay ◽  
Trichoderma Species ◽  
Soil Borne Pathogens ◽  
Trichoderma Sp ◽  
Trichoderma Isolates

Biocontrol is an important aspect of disease management for plant pathogens, especially for the soil borne fungi. Trichoderma species is the most exploited biocontrol agent in recent years. The soil specific nature of Trichoderma species is a well-known fact and hence native Trichoderma isolates should be more emphasized for control of plant pathogens. Fifty soil samples from rhizosphere of various agricultural crops were collected for isolation of Trichoderma sp. Ten isolates of Trichoderma were tested in dual culture with soil borne pathogens Fusarium solani, Rhizoctonia solani and Sclerotinia sclerotiorum in an in vitro assay. All of the test isolates were found to be significant in terms of mycelial inhibition growth as compared to control. However, varying degrees of antagonism by different Trichoderma isolates were observed for above mentioned soil borne pathogens. The isolate (T363) was found to exhibit more than 80% inhibition of S. sclerotiorum while the isolate T357 was found to control F. solani by more than 80%.  For the control of R. solani, six of the tested Trichoderma isolates showed more than 80% inhibition of its radial colony growth. The Trichoderma isolates seen effective in this study need to be tested in pot and field experiments for exploiting the use and benefits of biocontrol.

scholarly journals In Vitro Antagonism of Trichoderma Verede and Aspergillus Spp. against a Pathogenic Seed Borne Fungus of Sesame

2019 ◽  
Vol 43 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Md Delwar Hosen ◽  
Shamim Shamsi
Keyword(s):  
Aspergillus Flavus ◽  
Soil Fungi ◽  
Trichoderma Viride ◽  
Dual Culture ◽  
Volatile Metabolites ◽  
Inhibiting Effect ◽  
Antagonistic Potential ◽  
Academy Of Sciences ◽  
Growth Inhibiting

Four soil fungi were isolated from the soil by serial dilution and were identified as Aspergillus flavus Link, A. fumigatus Fresenius, A. niger van Tieghem and Trichoderma viride Pers. The soil fungi were selected to evaluate their antagonistic potential against seed borne fungus Fusarium merismoides isolated from sesame. In dual culture colony interaction Trichoderma viride showed the highest (45.88%) growth inhibiting effect on F. merismoides followed by A. niger (40.00%), A. flavus (36.37) and A. fumigatus (30.77%). Volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (67.69%) and non-volatile metabolites from T. viride showed the highest growth inhibiting effect on F. merismoides (75.00%). Journal of Bangladesh Academy of Sciences, Vol. 43, No. 1, 17-23, 2019

Antifungal activity of extracts from endophytic fungi associated with Smallanthus maintained in vitro as autotrophic cultures and as pot plants in the greenhouse

2012 ◽  
Vol 58 (10) ◽  
pp. 1202-1211 ◽  
Author(s):  
Luiz H. Rosa ◽  
Nurhayat Tabanca ◽  
Natascha Techen ◽  
Zhiqiang Pan ◽  
David E. Wedge ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Endophytic Fungi ◽  
Plant Pathogens ◽  
Cultivation Conditions ◽  
Smallanthus Sonchifolius ◽  
Fungal Plant Pathogens ◽  
In The Wild ◽  
Fungal Assemblages ◽  
Pot Plants

The endophytic fungal assemblages associated with Smallanthus sonchifolius (Poepp.) H. Rob. and Smallanthus uvedalius (L.) Mack. ex Small growing in vitro autotrophic cultures and in the greenhouse were identified and evaluated for their ability to produce bioactive compounds. A total of 25 isolates were recovered that were genetically closely related to species of the genera Bionectria , Cladosporium , Colletotrichum , Fusarium , Gibberella , Hypocrea , Lecythophora , Nigrospora , Plectosphaerella , and Trichoderma . The endophytic assemblages of S. sonchifolius presented a greater diversity than the group isolated from S. uvedalius and demonstrated the presence of dominant generalist fungi. Extracts of all fungi were screened against the fungal plant pathogens. Ten extracts (41.6%) displayed antifungal activities; some of them had a broad antifungal activity. The phylotypes Lecythophora sp. 1, Lecythophora sp. 2, and Fusarium oxysporum were isolated from in vitro autotrophic cultures and displayed antifungal activity. The presence of bioactive endophytic fungi within S. sonchifolius and S. uvedalius suggests an ecological advantage against pathogenic attacks. This study revealed reduced numbers of endophytes in association with both Smallanthus species in controlled cultivation conditions compared with the endophytic communities of hosts collected in the wild environments. Even as reduced endophytic communities, these fungi continue to provide chemical protection for the host.

The antagonistic properties of Trichoderma spp. inhabiting woods for potential biological control of wood-damaging fungi

Holzforschung ◽  
2012 ◽  
Vol 66 (7) ◽  
pp. 883-887 ◽  
Author(s):  
Jaejung Lee ◽  
Nayoon Huh ◽  
Joo Hyun Hong ◽  
Beom Seok Kim ◽  
Gyu-Hyeok Kim ◽  
...  
Keyword(s):  
Biological Control ◽  
Chitinase Activity ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Trichoderma Longibrachiatum ◽  
Antagonistic Effects ◽  
Volatile Metabolites ◽  
Antagonistic Potential ◽  
Trichoderma Aureoviride

Abstract The antagonistic potential of Trichoderma spp. for biological control of wood-damaging fungi was investigated in the present paper. In vitro assays to investigate antifungal characteristics of Trichoderma spp. were conducted with various wood-damaging fungi. Exo-chitinase activity of the isolates was also measured. Three typical wood decayers and three sap-stainers served as target fungi. The antagonistic abilities of each Trichoderma species differed markedly according to the target fungus. The growth inhibition rates shown by the non-volatile metabolites against the wood decayers reached 100% for Trichoderma harzianum KUC1459. The antibiotics produced by Trichoderma dorotheae KUC5027, a recently reported species of Trichoderma, revealed strong antagonistic effects against sap-stainers. Trichoderma gamsii KUC1747 effectively inhibited the growth of all wood-damaging fungi in dual culture tests. The exo-chitinases of Trichoderma longibrachiatum KUC1540, Trichoderma aureoviride KUC1335, and T. harzianum KUC1459 showed significantly high activity.

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