scholarly journals Pengaruh senyawa volatil yang dihasilkan bakteri endofit asal padi terhadap Rhizoctonia oryzae dan Cercospora oryzae

Agrikultura ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 61
Author(s):  
Fitri Widiantini ◽  
Endah Yulia ◽  
Agung Kurniawan
Keyword(s):  
Dual Culture ◽  
Rhizoctonia Oryzae

Penggunaan fungisida dalam mengendalikan penyakit pada tanaman telah banyak dilaporkan menimbulkan dampak negatif terutama terhadap lingkungan. Oleh karena itu diperlukan alternatif pengendalian lain yang lebih ramah lingkungan. Bakteri endofit telah banyak dimanfaatkan sebagai agens biokontrol pada berbagai penyakit tanaman karena  dikenal sebagai sumber penghasil senyawa-senyawa yang bersifat antifungal. Laboratorium Bioteknologi Proteksi Tanaman Fakultas Pertanian Universitas Padjadjaran memiliki koleksi beberapa bakteri endofit hasil isolasi asal tanaman padi yang masih dalam tahap pengujian. Penelitian ini dilakukan dengan tujuan untuk mengetahui potensi antijamur dari senyawa volatil yang dihasilkan oleh bakteri endofit dalam menekan pertumbuhan jamur Rhizoctonia oryzae penyebab penyakit bercak pelepah daun dan jamur Cercospora oryzae penyebab penyakit bercak daun secara in vitro. Percobaan dilakukan dengan metode dual culture dengan menggabungkan dua cawan dimana isolat bakteri endofit dan jamur patogen ditumbuhkan secara terpisah. Hasil pengujian menunjukkan bahwa isolat bakteri endofit Os1 dan Os2 memiliki kemampuan terbaik dalam menghambat patogen R. oryzae dengan persentase penghambatan pertumbuhan  masing-masing sebesar 68,7% dan 65,4%. Sedangkan isolat bakteri endofit Os3 adalah isolat bakteri endofit yang mempunyai kemampuan terbaik dalam menghambat perkembangan patogen C. oryzae dengan persentase penghambatan sebesar 87,1%. Pengamatan mikroskopis memperlihatkan bahwa senyawa volatil yang dikeluarkan oleh isolat-isolat bakteri endofit tersebut dapat menyebabkan terjadinya malformasi pada miselia jamur R. oryzae dan C. oryzae.

An Attempt at Biological Control of Blossom Blight of Rose Caused by Botrytis cinerea Using some Local Trichoderma spp. Strains

2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard
Keyword(s):  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Limiting Factor ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Khuzestan Province ◽  
Inhibitory Potential ◽  
Cut Rose

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.

scholarly journals Trichoderma asperellum T76-14 Released Volatile Organic Compounds against Postharvest Fruit Rot in Muskmelons (Cucumis melo) Caused by Fusarium incarnatum

2021 ◽  
Vol 7 (1) ◽  
pp. 46
Author(s):  
Warin Intana ◽  
Suchawadee Kheawleng ◽  
Anurag Sunpapao
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Cucumis Melo ◽  
Fungal Growth ◽  
Fruit Rot ◽  
Postharvest Disease ◽  
Dual Culture ◽  
Trichoderma Asperellum ◽  
Volatile Organic

Postharvest fruit rot caused by Fusarium incarnatum is a destructive postharvest disease of muskmelon (Cucumis melo). Biocontrol by antagonistic microorganisms is considered an alternative to synthetic fungicide application. The aim of this study was to investigate the mechanisms of action involved in the biocontrol of postharvest fruit rot in muskmelons by Trichoderma species. Seven Trichoderma spp. isolates were selected for in vitro testing against F. incarnatum in potato dextrose agar (PDA) by dual culture assay. In other relevant works, Trichoderma asperellum T76-14 showed a significantly higher percentage of inhibition (81%) than other isolates. Through the sealed plate method, volatile organic compounds (VOCs) emitted from T. asperellum T76-14 proved effective at inhibiting the fungal growth of F. incarnatum by 62.5%. Solid-phase microextraction GC/MS analysis revealed several VOCs emitted from T. asperellum T76-14, whereas the dominant compound was tentatively identified as phenylethyl alcohol (PEA). We have tested commercial volatile (PEA) against in vitro growth of F. incarnatum; the result showed PEA at a concentration of 1.5 mg mL−1 suppressed fungal growth with 56% inhibition. Both VOCs and PEA caused abnormal changes in the fungal mycelia. In vivo testing showed that the lesion size of muskmelons exposed to VOCs from T. asperellum T76-14 was significantly smaller than that of the control. Muskmelons exposed to VOCs from T. asperellum T76-14 showed no fruit rot after incubation at seven days compared to fruit rot in the control. This study demonstrated the ability of T. asperellum T76-14 to produce volatile antifungal compounds, showing that it can be a major mechanism involved in and responsible for the successful inhibition of F. incarnatum and control of postharvest fruit rot in muskmelons.

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 Antimicrobial activity of extracellular metabolites from antagonistic bacteria isolated from potato (Solanum phureja) crops

2014 ◽  
Vol 40 (3) ◽  
pp. 212-220 ◽  
Author(s):  
Sinar David Granada García ◽  
Antoni Rueda Lorza ◽  
Carlos Alberto Peláez
Keyword(s):  
Antimicrobial Activity ◽  
Cyclic Peptide ◽  
Biological Activities ◽  
Pathogenic Fungi ◽  
Antagonistic Activity ◽  
Solanum Phureja ◽  
Dual Culture ◽  
Crude Extracts ◽  
Extracellular Metabolites

Microorganisms for biological control are capable of producing active compounds that inhibit the development of phytopathogens, constituting a promising tool toob tain active principles that could replace synthetic pesticides. This study evaluatedtheability of severalpotentialbiocontrol microorganismsto produce active extracellular metabolites. In vitro antagonistic capability of 50 bacterial isolates from rhizospheric soils of "criolla" potato (Solanum phureja) was tested through dual culture in this plant with different plant pathogenic fungi and bacteria. Isolates that showed significantly higher antagonistic activity were fermented in liquid media and crude extracts from the supernatants had their biological activities assessed by optical density techniques. Inhibitory effecton tested pathogens was observed for concentrations between 0.5% and 1% of crude extracts. There was a correlation between the antimicrobial activity of extracts and the use of nutrient-rich media in bacteria fermentation. Using a bioguided method, a peptidic compound, active against Fusarium oxysporum, was obtained from the 7ANT04 strain (Pyrobaculum sp.). Analysis by nuclear magnetic resonance and liquid chromatography coupled to mass detector evidenced an 11-amino acid compound. Bioinformatic software using raw mass data confirmed the presence of a cyclic peptide conformed by 11 mostly non-standard amino acids.

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 Plant Growth Promotion and Biocontrol Properties of Aneurinibacillus migulanus Isolated from Maize Roots (Zea mays)

2021 ◽  
pp. 46-59
Author(s):  
Lynda Kelvin Asogwa ◽  
Frank C. Ogbo
Keyword(s):  
Zea Mays ◽  
Plant Growth ◽  
Plant Height ◽  
Pot Experiment ◽  
Root Weight ◽  
Dual Culture ◽  
Maize Roots ◽  
Plant Growth Promoting ◽  
Growth Promoting

Aims: To isolate Plant Growth Promoting Bacillus strain from maize roots, to evaluate its biocontrol potentials and to characterize the isolate using16S rRNA sequencing. Place and Duration of Study: Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, between February 2019 and March 2020. Methodology: The isolation of Plant Growth Promoting Rhizobacteria (PGPR) from maize roots was done using Pikovskaya (PVK) agar. Quantitative determination of phosphate was carried out using PVK broth. Evaluations of other plant growth promoting properties were carried out such as IAA, etc. Fusarium and Enterobacter plant pathogens were isolated from diseased maize plants. The in vitro antagonism effects of the PGPR isolates against the pathogens were analyzed using the dual culture plate technique. The pot experiment was carried out in a completely randomized design. Plant characteristics such as plant height, shoot  and root weight, chlorophyll content, as well as disease assessment were recorded accordingly. The organisms were identified using phenotypic and molecular methods. Results: Seven PGPR bacteria were isolated from maize (Zea mays) roots using PVK agar. Aneurinibacillus migulanus gave the highest solubilization index of 4.21 while isolate IS48 gave the lowest solubilization index of 1.47. A. migulanus produced IAA, ammonia and cellulase enzyme but no hydrogen cyanide. The organism showed antagonism activity against the two tested phytopathogens. In the pot experiment, A. migulanus treated plants showed a statistically insignificant difference in maize plant height at P=0.05 but gave significant increases in shoot and root wet weights. The organism offered 83.33% and 71.43% protection against Enterobacter and Fusarium pathogens respectively in the pot experiment. Conclusion: A. migulanus solubilized phosphate in addition to other plant growth promoting  properties. It showed biocontrol potentials both in vitro and in vivo and thus can be used as substitute for synthetic agrochemicals.

scholarly journals Suppression of Stem-End Rot on Avocado Fruit Using Trichoderma spp. in the Central Highlands of Kenya

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
E. K. Wanjiku ◽  
J. W. Waceke ◽  
J. N. Mbaka
Keyword(s):  
Growth Inhibition ◽  
Fungal Pathogen ◽  
Mycelial Growth ◽  
Culture Technique ◽  
Global Market ◽  
Dual Culture ◽  
Postharvest Diseases ◽  
Trichoderma Spp ◽  
Lasiodiplodia Theobromae

Demand for organic avocado fruits, together with stringent food safety standards in the global market, has made producers to use alternative, safe, and consumer-friendly strategies of controlling the postharvest fungal disease of avocado fruits. This study assessed the in vitro efficacy of Trichoderma spp. (T. atroviride, T. virens, T. asperellum, and T. harzianum) against isolated avocado stem-end rot (SER) fungal pathogens (Lasiodiplodia theobromae, Neofusicoccum parvum, Nectria pseudotrichia, and Fusarium solani) using a dual culture technique. The Trichoderma spp. were also evaluated singly on postharvest “Hass” avocado fruits. Spore suspension at 5 × 104 conidial/ml of the Trichoderma spp. was applied on the avocado fruits at three time points, twenty-four hours before the fungal pathogen (preinoculation), at the same time as the fungal pathogen (concurrent inoculation), and 24 hours after the fungal pathogen (postinoculation). In the in vitro study, T. atroviride showed the highest mycelial growth inhibition against N. parvum (48%), N. pseudotrichia (55%), and F. solani (32.95%), while T. harzianum had the highest mycelial growth inhibition against L. theobromae. Trichoderma asperellum was the least effective in inhibiting the mycelial growth of all the pathogens. Similarly, T. virens showed the highest mycelial growth inhibition against N. pseudotrichia at 45% inhibition. On postharvest “Hass” fruits, T. atroviride showed the highest efficacy against N. parvum, N. pseudotrichia, and F. solani in all the applications. Trichoderma virens and T. harzianum were most effective against all the pathogens during postinoculation, while Lasiodiplodia theobromae was best controlled by T. virens, T. harzianum, and T. asperellum during postinoculation. Both T. atroviride and T. harzianum present a potential alternative to synthetic fungicides against postharvest diseases of avocado fruits, and further tests under field conditions to be done to validate their efficacy. The possibility of using Trichoderma spp. in the management of SER on avocado fruits at a commercial level should also be explored.

scholarly journals Antagonistic effectiveness of some bacteria against Fusarium graminearum causing crown rot disease on wheat (Triticum aestivum)

2021 ◽  
Vol 13 (1) ◽  
pp. 69-80
Author(s):  
Majida Hadi Mahdi Alsaady ◽  
Hussein Ali Salim ◽  
Rakib A. Al-ani ◽  
Hadi M. Aboud ◽  
Jamal Talib M Al Roubaie
Keyword(s):  
Fusarium Graminearum ◽  
Culture Method ◽  
Dry Weight ◽  
Antagonistic Effect ◽  
Crown Rot ◽  
Control Treatment ◽  
Enzyme Analysis ◽  
Dual Culture ◽  
Rot Disease

In this study, the antagonistic effect of five bacteria genera namely Bacillus, Pseudomonas, Azotobacter, Azospirillum, and Streptomyces isolated from rhizosphere of wheat were evaluated against Fusarium graminearum as potential biocontrol agents in vitro. F. graminearum was molecularly diagnosed using the Polymerase chain reaction (PCR) technique. Each bacteria were tested for the production of catalase enzyme, oxidase enzyme, analysis of starch, analyze of gelatin, and the motility, where Azotobacter, Azospirillum, and Bacillus subtilis were positive for all tested. Fungal inhibition tests were performed by using the dual culture method and agar well diffusion technique. Among them, Streptomyces and Azospirillum exhibited potent inhibition to the growth of F. graminearum (72.14% and 66.42%) respectively, followed by B.pumillus, P.fluorescens, B. subtilis and Azotobacter ( 58.28%, 43.23%, 39.71% and 35.71%) respectively as compared with the control treatment (0.0%).The dry weight of the fungus biomass was decreased with bacteria P. fluorescens, Streptomyces sp, Azotobacter sp, Azospirillum sp, B. subtilis, and B. pumillus which reached (0.114, 0.103, 0.147, 0.101, 0.143, and 0.107 g) respectively compared to the control treatment that was 0. 665 g.

scholarly journals EKSPLORASI DAN IDENTIFIKASI CENDAWAN ANTAGONIS TERHADAP JAMUR AKAR PUTIH (Rigidoporus lignosus) PADA TANAMAN PALA (Myristica fragrans Houtt)

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Nana Ariska ◽  
Lola Adres Yanti ◽  
Chairudin Chairudin
Keyword(s):  
Economic Value ◽  
Culture Method ◽  
Dilution Method ◽  
Dual Culture ◽  
Trichoderma Spp ◽  
Pests And Diseases ◽  
Myristica Fragrans ◽  
Rigidoporus Lignosus ◽  
Myristica Fragrans Houtt

Nutmeg (Myristica fragrans Houtt) is a multipurpose plantation commodity crop that almost all parts of the plant have strategic economic value to be cultivated. In Indonesia there are the largest nutmeg commodity centers, including the Maluku islands, North Sulawesi and Aceh. The biggest problem with nutmeg plants is the attack of pests and diseases. One of the most severe diseases in nutmeg is white root mushroom (Rigidoporus lignosus). This study aims to 1) determine the fungus of white root fungus antagonists (Rigodoporus lignosus) from the Aceh nutmeg rhizosphere (Myristica fragrans Houtt), 2) identify the content of antibiotic fungus JAP antagonist compounds in Aceh nutmeg plants. The study was conducted by taking soil samples from nutmeg plants at three nutmeg plantations in South Aceh. The antagonist fungus isolation activity uses a dilution method. Isolation of JAP from infected roots using direct planting method. Furthermore, it is identified macroscopically and microscopically. The antagonist test was carried out using the dual culture method with RAL. From the rhizosphere in the nutmeg area, 5 candidate antagonist isolates were obtained, having high in vitro antagonism ability to the pathogen R. lignosus. Identification results showed that isolates 1, 2 and 3 were Trichoderma spp, and isolates 4 and 5 were Gliocladium virens. Keywords: In vitro, the content of antibiotic compounds, Aceh nutmeg, Rigidoporus lignosus, antagonistic test

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