scholarly journals Screening of Fungal Endophytes for their Biocontrol Potential against Rhizopus sp. Isolated from Diseased Cassava (Manihot esculenta Crantz)

2021 ◽  
Vol 4 (2) ◽  
pp. 25-37
Author(s):  
Onyemaechi H.O. ◽  
Obehi V.O. ◽  
Felix O.

The aim of this study was to screen for the bio-control potential of fungal endophytes isolated from cassava against a test pathogen of cassava. Fungal endophytes and pathogen were isolated and identified from healthy and diseased cassava respectively. The isolated fungal endophytes were screened for their biocontrol potential against a test pathogen using the dual culture and culture filtrate assay. Fusarium sp., Botryosphaeria sp., Colletotrichum sp., yeast isolate 1 and 2 were the isolated fungal endophytes while the pathogen was Rhizopus sp. The effect of endophytes on the mycelia growth of Rhizopus sp. using the dual culture assay indicated that yeast isolate 1 & 2 and Colletotrichum sp. were effective in inhibiting the mycelia growth of the test pathogen while Fusarium sp. and Botryosphaeria sp. were not effective. The co-culture of yeast isolate 2 with the test pathogen gave the lowest mycelia growth (1.66a±0.09) at day 2. The effect of endophytic culture filtrate on the mycelia growth of Rhizopus sp. showed that Fusarium sp. gave the lowest mycelia growth in the three days observed. The findings from this study suggested that the test endophytes have biocontrol potential against Rhizopus sp. The biocontrol abilities of the test endophytes vary using the dual culture and culture filtrate assay.

2017 ◽  
Vol 2 (6) ◽  
pp. 287 ◽  
Author(s):  
Fitri Widiantini ◽  
Andri Herdiansyah ◽  
Endah Yulia

Isolation was attempted to collect endophytic bacteria as potential biocontrol agents against rice blast disease (Pyricularia oryzae Cav.). The disease is one of major threats in rice production as it can cause 100% yield loss. Concern on the environment and human health has led to the searching of alternative controlling method to replace the commonly used pesticide-based method. Endophytic bacteria are bacteria that have intimate relationship with their host without inducing any pathogenic symptom. The use of endophytic microbial as biocontrol agent has its own advantages as the microbes are more easily to adapt to the environment needed by the host plant. We evaluated endophytic bacteria isolated from healthy rice plants and tested for their potential biocontrol activity using dual culture assay. Ten isolates were found to inhibit the growth of P. oryzae of more than 50%. Microscopic observation showed that they were able to cause the mycelia malformation of P. oryzae. Further work is currently in progress to determine their effectiveness in the pot trial. Keywords: Endophytic bacteria; Pyricularia oryzae; biocontrol.


2021 ◽  
Vol 15 (1) ◽  
pp. 10-20
Author(s):  
Tsegaye Mekuria Ayele ◽  
Guesh Desta Gebremariam ◽  
Subban Patharajan

Introduction: Tomato production in Ethiopia is challenged by many pests and diseases. Fusarium wilt is one of the most important diseases of tomato affecting its productivity. Methods: Tomato tissue and soil samples were collected from tomato farmlands around Aksum town to isolate and identify pathogenic Fusarium species and Trichoderma species with biocontrol efficacy. Samples were processed in the Aksum University Biotechnology laboratory following standard procedures. Results and Discussion: Eight Fusarium and five Trichoderma isolates were obtained. Six of the Fusarium isolates were identified as Fusarium oxysporum, whereas the remaining two were Fusarium equiseti and Fusarium circinatum. Detached leaf bioassay of the F. oxysporum on tomato leaves showed leaf lesion on the tomato variety, Melka oda. The isolated Trichoderma strains were screened for biocontrol potential against virulent F. oxysporum in vitro. The Trichoderma isolate showing the highest biocontrol efficacy against the virulent Fusarium was morphologically identified as Trichoderma viride. in vitro F. oxysporum-T. viride dual culture assay demonstrated that T. viride inhibits the growth of F. oxysporum f.sp. lycopersici with 76.94% growth inhibition. Conclusion: Fusarium oxysporum is prevalent in tomato growing farmlands covered in this study. T. viride identified in this study is an effective biocontrol agent for the identified F. oxysporum fsp. lycopersici in vitro.


2020 ◽  
Vol 8 (6) ◽  
pp. 955 ◽  
Author(s):  
Krishni Fernando ◽  
Priyanka Reddy ◽  
Inoka K. Hettiarachchige ◽  
German C. Spangenberg ◽  
Simone J. Rochfort ◽  
...  

Asexual Epichloë spp. fungal endophytes have been extensively studied for their functional secondary metabolite production. Historically, research mostly focused on understanding toxicity of endophyte-derived compounds on grazing livestock. However, endophyte-derived compounds also provide protection against invertebrate pests, disease, and other environmental stresses, which is important for ensuring yield and persistence of pastures. A preliminary screen of 30 strains using an in vitro dual culture bioassay identified 18 endophyte strains with antifungal activity. The novel strains NEA12, NEA21, and NEA23 were selected for further investigation as they are also known to produce alkaloids associated with protection against insect pests. Antifungal activity of selected endophyte strains was confirmed against three grass pathogens, Ceratobasidium sp., Dreschlera sp., and Fusarium sp., using independent isolates in an in vitro bioassay. NEA21 and NEA23 showed potent activity against Ceratobasidium sp. and NEA12 showed moderate inhibition against all three pathogens. Crude extracts from liquid cultures of NEA12 and NEA23 also inhibited growth of the phytopathogens Ceratobasidium sp. and Fusarium sp. and provided evidence that the compounds of interest are stable, constitutively expressed, and secreted. Comparative analysis of the in vitro and in planta metabolome of NEA12 and NEA23 using LCMS profile data revealed individual metabolites unique to each strain that are present in vitro and in planta. These compounds are the best candidates for the differential bioactivity observed for each strain. Novel endophyte strains show promise for endophyte-mediated control of phytopathogens impacting Lolium spp. pasture production and animal welfare.


2021 ◽  
Vol 7 (3) ◽  
pp. 224
Author(s):  
Dennice G. Catambacan ◽  
Christian Joseph R. Cumagun

The antagonistic activity of fungal endophytes isolated from weeds growing in Cavendish banana farms was determined against Fusarium oxysporum f. sp. cubense TR4 (Foc TR4) causing Fusarium wilt of Cavendish banana. Forty-nine out of the total 357 fungal endophytes from the roots of weeds exhibited antagonistic activity against Foc TR4. High inhibitory activity at 79.61–99.31% based on dual culture assay was recorded in endophytes Lasiodiplodia theobromae TDC029, Trichoderma asperellum TDC075, Ceratobasidium sp. TDC037, Ceratobasidium sp. TDC241, and Ceratobasidium sp. TDC474. All five endophytes were identified through DNA sequencing with 86–100% identity. Endophyte-treated Grand Naine and GCTCV 218 plantlets showed significantly lower disease incidence (p = 0.014), significantly lower degree of leaf yellowing (p = 0.037) and rhizome discoloration (p = 0.003). In addition, the cultivar Grand Naine was consistently highly susceptible compared with the tolerant cultivar GCTCV 218.


2009 ◽  
Vol 55 (4) ◽  
pp. 395-404 ◽  
Author(s):  
Matin Mohammadipour ◽  
Maryam Mousivand ◽  
Gholamreza Salehi Jouzani ◽  
Saeed Abbasalizadeh

The characterization of surfactin-producing Bacillus subtilis isolates collected from different ecological zones of Iran is presented. Characterization was performed using blood agar, PCR, drop-collapse, and reverse-phase high-performance liquid chromatography (HPLC) analyses, and the isolates’ biocontrol effects against the aflatoxin-producing agent Aspergillus flavus and the citrus antracnosis agent Colletotrichum gloeosporioides were studied. In total, 290 B. subtilis isolates were isolated from phylosphere and rhizosphere samples collected from fields and gardens of 5 provinces of Iran. Blood agar assays showed that 185 isolates produced different biosurfactants. Isolates containing the sfp gene, coding for surfactin, were detected using the PCR method. It was found that 14 different isolates contained the sfp gene. Drop-collapse assays, which detect isolates with high production of surfactin, showed that 7 isolates produced high levels of surfactin. It was found from HPLC analysis that the isolates containin the sfp gene produced between 55 and 1610 mg of surfactin per litre of broth medium. Four isolates, named BS119m, BS116l, N3dn, and BS113c, produced more than 1000 mg of surfactin per litre of broth. The highest surfactin production level was observed for isolate BS119m (1610 mg/L). The antagonistic potential of the sfp gene-containing isolates was determined using dual culture and chloroform vapour methods. Our bioassay results indicated that isolate BS119m showed high inhibitory effects against A. flavus (100%) and C. gloeosporioides (88%). Furthermore, the effect of purified surfactin on the growth of A. flavus was evaluated. Mycelia growth was considerably reduced with increasing concentration of surfactin, and 36%, 54%, 84%, and 100% inhibitions of mycelia growth were, respectively, observed at 20, 40, 80, and 160 mg/L after 7 days of incubation.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Sezai Türkel ◽  
Mihriban Korukluoğlu ◽  
Mümine Yavuz

The strains of the yeastMetschnikowia pulcherrimahave strong biocontrol activity against various microorganisms. Biocontrol activity ofM. pulcherrimalargely depends on its iron immobilizing pigment pulcherrimin. Biocontrol activity of pulcherrimin producing strain,M. pulcherrimaUMY15, isolated from local vineyards, was tested on different molds that cause food spoilage.M. pulcherrimaUMY15 was a very effective biocontrol agent againstPenicillium roqueforti,P. italicum,P. expansum, andAspergillus oryzaein in-vitro plate tests. However, the inhibitory activity ofM. pulcherrimaUMY15 was less effective onFusarium sp.andA. nigerspecies in biocontrol assays. In addition,M. pulcherrimaUMY15 strain completely inhibited the germination and mycelia growth ofA. oryzae,A. parasiticus, andFusariumsp. spores on artificial wounds of apples when they coinoculated withM. pulcherrimaUMY15. Moreover, when coinoculated,M. pulcherrimaUMY15 strain also inhibited the growth ofP. roqueforti,P. italicum,P. expansum,A. oryzae,Fusarium sp., andRhizopus sp. in grape juice, indicating thatM. pulcherrimaUMY15 can be used as a very effective biocontrol yeast against various species of postharvest pathogens, including   Penicillium,Aspergillus,Fusarium, andRhizopus.


2020 ◽  
Vol 27 (3) ◽  
pp. 209
Author(s):  
Nur Afeeqah Binti Mohamed Zanudin ◽  
Nor'Aishah Hasan ◽  
Patahayah Binti Mansor

The extensive use of synthetic fungicides in controlling plant disease generates detrimental impacts on the environment and human health. In response to this problem, an alternative method was developed, known as biological control using antagonistic microorganisms. Since investigation on fungal endophytes of Garcinia atroviridis is still unclear, it was chosen for the study. The aim of the present work was to evaluate biocontrol potential of endophytic fungi against Colletotrichum gloeosporiodes, a phytopathogen that caused anthracnose disease. A total of 92 endophytic fungi were isolated from different tissue parts of Garcinia atroviridis including leaves, petioles, branches, and fruits. Results demonstrated that, most of endophytic fungal isolates showed some inhibitory action over the growth of C. gloeosporiodes during dual culture growth. Endophyte isolate F14 showed the highest antagonistic activity against Colletotrichum gloeosporiodes with 67.38% percentage inhibition radial growth (PIRG). However, 7 out of 92 isolates showed no inhibitory effect against Colletotrichum gloeosporiodes. In conclusion, endophytic fungi isolated from G. atroviridis indicate the potential as biocontrol agents. It is hoped that the finding of isolated endophytic fungi in this study with antagonistic activity against anthracnose pathogen may be used in biocontrol programmes of plant disease in the region.


Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 165
Author(s):  
Barbara Abramczyk ◽  
Anna Marzec-Grządziel ◽  
Jarosław Grządziel ◽  
Ewa Król ◽  
Anna Gałązka ◽  
...  

Recently, Diaporthe has been considered the most frequently isolated genera of endophytic fungi, having a broad spectrum of host plants and a worldwide distribution. The endophytic Diaporthe strain used in the present work came from the Fungal Collection of Phytopathology and Mycology Subdepartment, University of Life Sciences in Lublin (Poland), and was isolated from healthy Prunus domestica shoots during previous studies. Due to the possibility of using the Diaporthe endophytes as a promising option for plant disease management, the main goal of the research was to study the antagonistic effect of endophytic Diaporthe strain against six phytopathogens: Verticillium dahliae, Botrytis cinerea, Fusarium avenaceum, F. sprotrichioides, Alternaria alternata, and Trichothecium roseum based on the dual culture assay and to determine the catabolic profile of the endophyte by using Biolog FF Plates. The dual-culture test assay revealed the ability of the endophytic Diaporthe to limit the growth of all tested pathogens. The growth inhibition percentage ranged from 20% (V. dahliae) to 40% (T. roseum). A distinct zone of inhibition occurred between the endophytic Diaporthe and the pathogens T. roseum, V. dahliae, and B. cinerea in the co-growth combinations. As for the catabolic profile results, the most intensive utilization of carbon substrates was observed after 168 h of incubation. The growth of the analyzed strain was observed on 79 media containing carbohydrates, carboxylic acids, amino acids, amines and amides, polymers, and others. The most effective decomposition was observed in the polymers group, the least in amines and amides. Molecular identification indicated that this strain was closely related to the Diaporthe eres species complex.


Author(s):  
Sharon Pelo ◽  
Vuyo Mavumengwana ◽  
Ezekiel Green

Plant endophytes are microbial sources of bioactive secondary metabolites, which mimic the natural compounds chemistry of their respective host plants in a similar manner. This study explored the isolation and identification of fungal endophytes, and investigated the antibacterial and antimycobacterial activity of their crude extracts. Fungal endophytes were isolated from Solanum mauritianum, identified using morphological traits and internal transcribed spacer ribosomal-deoxyribonucleic acid (ITS-rDNA) sequence analysis. Eight fungal endophytes were identified as Aureobasidium pullulans, Paracamarosporium leucadendri, Cladosporium sp., Collectotrichum boninense, Fusarium sp., Hyalodendriella sp., and Talaromyces sp., while Penicillium chrysogenum was isolated from the leaves and unripe fruits. Good activity was observed for the crude extracts of Paracamarosporium leucadendri inhibiting Mycobacterium bovis, Klebsiella pneumoniae, and Pseudomonas aeruginosa at 6 µg/mL. Crude extracts of Fusarium sp., showed activity at 9 μg/mL against M. bovis, M. smegmatis and K. pneumonia. In general, the crude extracts showed great activity against Gram-negative and Gram-positive bacteria and novel results for two mycobacteria species M. bovis and M. smegmatis. The results provide evidence of diverse fungal endophytes isolated from Solanum mauritianum, and evidence that fungal endophytes are a good source of bioactive compounds with pharmaceutical potential, particularly against Mycobacterium tuberculosis.


2017 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Tatsuya Ohike ◽  
Minori Maeda ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
...  

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.


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