In vitro antagonism of endophytic Fusarium oxysporum isolates against the burrowing nematode Radopholus similis

Nematology ◽  
2006 ◽  
Vol 8 (4) ◽  
pp. 627-636 ◽  
Author(s):  
Bjoern Niere ◽  
Shahasi Athman ◽  
Altus Viljoen ◽  
Clifford Gold ◽  
Thomas Dubois ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Mortality Rates ◽  
Antagonistic Activity ◽  
Radopholus Similis ◽  
Biological Control Agents ◽  
Inhibitory Effects ◽  
Culture Filtrates ◽  
Burrowing Nematode ◽  
Nematode Mortality

AbstractRadopholus similis is one of the key pests of banana worldwide. In this study, nine endophytic Fusarium oxysporum isolates were screened for the production of secondary metabolites antagonistic to R. similis in culture. Undiluted and diluted culture filtrates were tested against motile stages and eggs of R. similis. All isolates tested demonstrated in vitro antagonistic activity, causing paralysis of R. similis motile stages. The percentage of paralysed nematodes increased with increase in the length of exposure time to culture filtrates. After 24 h exposure in culture filtrates up to 100% of the treated nematodes were paralysed compared to 26.5% in the control treatments. Nematode mortality rates after 24 h exposure in culture filtrates ranged from 76.4% to 100%. Paralysis was reversible at lower filtrate concentrations. Radopholus similis males were more sensitive to culture filtrates than females. Culture filtrates of all isolates demonstrated inhibitory effects on hatching of R. similis eggs. The results demonstrate the potential for using endophytic F. oxysporum as biological control agents against R. similis and for toxic derivatives from their secondary metabolism to be used as potential nematicides.

Effect of endophytic Fusarium oxysporum on root penetration and reproduction of Radopholus similis in tissue culture-derived banana (Musa spp.) plants

Nematology ◽  
2007 ◽  
Vol 9 (5) ◽  
pp. 599-607 ◽  
Author(s):  
Altus Viljoen ◽  
Nico Labuschagne ◽  
Thomas Dubois ◽  
Shahasi Athman ◽  
Daniel Coyne ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Fusarium Oxysporum ◽  
Root Penetration ◽  
Host Searching ◽  
Radopholus Similis ◽  
Biological Control Agents ◽  
Nematode Reproduction ◽  
Musa Spp ◽  
Plant Infection ◽  
Burrowing Nematode

AbstractIn Uganda, banana (Musa spp.) production is constrained by the burrowing nematode Radopholus similis. Non-pathogenic, endophytic Fusarium oxysporum has been isolated from healthy banana plants, and several strains have shown potential as biological control agents against R. similis. Plant infection by R. similis can be characterised in three steps: host searching, root penetration and reproduction. In this study, we investigated the effects of three endophytic F. oxysporum strains (Eny1.31i, Eny7.11o and V5w2) on root penetration and reproduction of R. similis in tissue culture-derived banana plants. The number of R. similis that penetrated roots of endophyte-inoculated and untreated plants was not influenced by the endophytes in either laboratory or screenhouse experiments. However, R. similis reproduction was reduced by endophytes. Strain V5w2 gave the greatest suppression of R. similis reproduction. The results of this study imply that antagonism of endophytic F. oxysporum against R. similis in banana plants is post-infectional and mediated through disruption of nematode reproduction.

Attraction and penetration of Musa by the burrowing nematode, Radopholus similis, in an autotrophic bipartite culture system

Nematology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Suganthagunthalam Dhakshinamoorthy ◽  
Erwin J. Galon ◽  
Annemie Elsen ◽  
Dirk De Waele
Keyword(s):  
Culture System ◽  
Model System ◽  
Radopholus Similis ◽  
Susceptible Plant ◽  
Compartment System ◽  
Female Migration ◽  
Equal Distance ◽  
Burrowing Nematode ◽  
Nematode Chemotaxis

Summary Our objective was to discover the stages (pre- or post-infection) in which the resistance to burrowing nematode (Radopholus similis) occurs in two resistant banana (Musa spp.) cultivars. An autotrophic in vitro culture system was used to compare R. similis migration towards, and penetration into, the banana roots. A new two-compartment autotrophic in vitro model system was developed using agar-based medium to examine the migration of R. similis to either the susceptible ‘Grande Naine’ or the resistant ‘Yangambi km5’ (‘Ykm5’), when both the Musa genotypes were present at equal distance. The autotrophic in vitro model system was advantageous, because it supported continuous root growth due to the actively photosynthesising shoots growing in the open air, while the in vitro root conditions make it possible to observe and assess the nematode chemotaxis in the transparent medium. Significantly fewer nematodes migrated towards the resistant ‘Ykm5’ plants when compared to both the susceptible ‘Grande Naine’, and another resistant cultivar, ‘Saba’, at 1 h after infection. This signals a possibility of a lower concentration or different composition of nematode attractants in ‘Ykm5’ root exudates. No significant differences were observed in the percentage of R. similis that migrated towards the roots of the susceptible and resistant banana plants at 3, 4 and 6 h after inoculation. No significant differences were observed in the percentages of female penetration in the resistant and susceptible plant roots at 1 and 2 days after inoculation. The results of the two-compartment system confirmed that when a choice is given to migrate towards the resistant and susceptible genotypes, no differences were observed in the percentage of female migration towards both the genotypes.

scholarly journals Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic condition

2020 ◽  
Vol 21 (7) ◽  
Author(s):  
SUPRIYANTO ◽  
PURWANTO ◽  
S.H. POROMARTO ◽  
SUPYANI
Keyword(s):  
Biological Control ◽  
Antagonistic Activity ◽  
Biological Control Agents ◽  
Antagonistic Fungi ◽  
High Incidence ◽  
Acidic Conditions ◽  
Mineral Soils ◽  
Ph Range ◽  
Biological Methods

Abstract. Supriyanto, Purwanto, Poromarto SH, Supyani. 2020. Evaluation of in vitro antagonistic activity of fungi from peatlands against Ganoderma species under acidic conditions. Biodiversitas 21: 2935-2945. The use of peatlands is a significant contributor to the world’s palm oil production. A serious problem of oil palm plantations in peatlands is the high incidence of basal stem rot (BSR) disease caused by Ganoderma, which has a higher attack rate than on mineral soils. There is no effective way to control Ganoderma in peatlands. At present, the effort for the same focuses on environment-friendly biological methods; however, this is constrained by the unavailability of appropriate biological agents for peatlands. The development of biological control agents for peatlands is hampered by limited data on biological control of Ganoderma in peatlands. This research was conducted to evaluate the in vitro antagonistic activity of fungi isolated from a peatland in acidic pH conditions. Twenty-seven Ganoderma-antagonistic fungi from peatland were evaluated for their activity and their ability to antagonism in vitro within a pH range of 2-7. The results show that most antagonistic fungi from peatland, based on biomass weight, the sporulation ability, and germination of conidium, were able to grow optimally at pH 3.0-4.0, indicating that most of the Ganoderma-antagonistic fungi from peatland can be used as biological control agents for BSR on oil palms in peatlands.

scholarly journals Self-Inhibitory Activity of Trichoderma Soluble Metabolites and Their Antifungal Effects on Fusarium oxysporum

2020 ◽  
Vol 6 (3) ◽  
pp. 176
Author(s):  
Samuel Álvarez-García ◽  
Sara Mayo-Prieto ◽  
Santiago Gutiérrez ◽  
Pedro Antonio Casquero
Keyword(s):  
Fusarium Oxysporum ◽  
Inhibitory Activity ◽  
Inhibitory Effects ◽  
Trichoderma Spp ◽  
Macroscopic Structure ◽  
Biocontrol Activity ◽  
Microbial Strains ◽  
Phytopathogenic Microorganisms

Self-inhibitory processes are a common feature shared by different organisms. One of the main mechanisms involved in these interactions regarding microorganisms is the release of toxic diffusible substances into the environment. These metabolites can exert both antimicrobial effects against other organisms as well as self-inhibitory ones. The in vitro evaluation of these effects against other organisms has been widely used to identify potential biocontrol agents against phytopathogenic microorganisms. In the present study, we performed membrane assays to compare the self-inhibitory effects of soluble metabolites produced by several Trichoderma isolates and their antifungal activity against a phytopathogenic strain of Fusarium oxysporum. The results demonstrated that Trichoderma spp. present a high self-inhibitory activity in vitro, being affected in both their growth rate and the macroscopic structure of their colonies. These effects were highly similar to those exerted against F. oxysporum in the same conditions, showing no significant differences in most cases. Consequently, membrane assays may not be very informative by themselves to assess putative biocontrol capabilities. Therefore, different methods, or a combination of antifungal and self-inhibitory experiments, could be a better approach to evaluate the potential biocontrol activity of microbial strains in order to pre-select them for further in vivo trials.

scholarly journals Recovery of Fusarium oxysporum Fo47 Mutants Affected in Their Biocontrol Activity After Transposition of the Fot1 Element

2002 ◽  
Vol 92 (9) ◽  
pp. 936-945 ◽  
Author(s):  
Sophie Trouvelot ◽  
Chantal Olivain ◽  
Ghislaine Recorbet ◽  
Quirico Migheli ◽  
Claude Alabouvette
Keyword(s):  
Fusarium Oxysporum ◽  
Insertional Mutagenesis ◽  
Wild Type Strain ◽  
Growth Habit ◽  
Antagonistic Activity ◽  
Phenotypic Characterization ◽  
Wild Type ◽  
Biocontrol Activity

To investigate the biocontrol mechanisms by which the antagonistic Fusarium oxysporum strain Fo47 is active against Fusarium wilt, a Fot1 transposon-mediated insertional mutagenesis approach was adopted to generate mutants affected in their antagonistic activity. Ninety strains in which an active Fot1 copy had transposed were identified with a phenotypic assay for excision and tested for their biocontrol activity against F. oxysporum f. sp. lini on flax in greenhouse experiments. Sixteen strains were affected in their capacity to protect flax plants, either positively (more antagonistic than Fo47) or negatively (less antagonistic). The molecular characterization of these mutants confirms the excision of Fot1 and its reinsertion in most of the cases. Moreover, we demonstrate that other transposable elements such as Fot2, impala, and Hop have no transposition activity in the mutant genomes. The phenotypic characterization of these mutants shows that they are affected neither in their in vitro growth habit nor in their competitiveness in soil compared with wild-type strain Fo47. These results show that mutants are not impaired in their saprophytic phase and suggest that the altered biocontrol phenotype should likely be expressed during the interaction with the host plant.

Effects of Streptomyces corchorusii, Streptomyces mutabilis, pendimethalin, and metribuzin on the control of bacterial and Fusarium wilt of tomato

1996 ◽  
Vol 74 (7) ◽  
pp. 1016-1022 ◽  
Author(s):  
Abd El-Raheem R. El-Shanshoury ◽  
Soad M. Abu El-Sououd ◽  
Omima A. Awadalla ◽  
Nabila B. El-Bandy
Keyword(s):  
Fusarium Oxysporum ◽  
Culture Media ◽  
Disease Incidence ◽  
Inhibitory Effects ◽  
Pseudomonas Solanacearum ◽  
Negative Effects ◽  
Streptomyces Spp ◽  
Antagonistic Streptomyces

Two Streptomyces spp. and two herbicides were used to control the pathogens of tomato wilt disease in vitro and in vivo. In vitro studies showed inhibitory effects of Streptomyces corchorusii against Fusarium oxysporum f.sp. lycopersici (Sacc.) and inhibitory effects of Streptomyces mutabilis against Pseudomonas solanacearum. In cultures amended with pendimethalin or metribuzin, the growths of P. solanacearum and F. oxysporum were inhibited. The degree of growth inhibition was proportional to the herbicide concentration, with pendimethalin being more effective than metribuzin, and maximum inhibition was at 2.0 × 10−3 M. The growth of S. corchorusii and S. mutabilis was slightly inhibited or enhanced by the herbicides. Supplementation of the herbicides to culture media of the antagonistic Streptomyces spp. increased their inhibitory effects against P. solanacearum and F. oxysporum that were proportional to the herbicide concentrations. Soaking seeds of tomato in the herbicides prior to sowing in sterilized and raw soils and applying S. corchorusii and (or) S. mutabilis to the soils artificially infested with P. solanacearum and (or) F. oxysporum f.sp. lycopersici (Sacc.) 40 days after transplanting revealed significant interactions that gave better control of wilt than either applied alone. The combination of antagonistic Streptomyces spp. was more effective with pendimethalin than with metribuzin and in nonsterilized soil than in sterilized soil. The combination of pendimethalin with S. corchorusii, S. mutabilis, or S. corchorusii plus S. mutabilis was more effective than the single treatment with microbial antagonists or the herbicide against F. oxysporum, P. solanacearum, and Pseudomonas plus Fusarium, respectively. In both soils, the combination of microbial antagonists with pendimethalin was most effective at 2.0 × 10−3 M, disease incidence being reduced to zero and the percent colonization of either pathogen being the lowest. The results also revealed that these combinations minimized the negative effects of the pathogens on tomato growth. This work demonstrates that two compatible control agents, biological and chemical, can be combined to give additional control of a plant pathogen. Keywords: Streptomyces spp., herbicides, Pseudomonas solanacearum, Fusarium oxysporum f.sp. lycopersici (Sacc.), wilt, Lycopersicon esculentum Mill.

In vitro phytotoxicity of culture filtrates of Fusarium oxysporum f. sp. vanillae in Vanilla planifolia Jacks

2015 ◽  
Vol 197 ◽  
pp. 573-578 ◽  
Author(s):  
Marco Antonio Ramírez-Mosqueda ◽  
Lourdes Georgina Iglesias-Andreu ◽  
Mauricio Luna-Rodríguez ◽  
Alejandro Antonio Castro-Luna
Keyword(s):  
Fusarium Oxysporum ◽  
Vanilla Planifolia ◽  
Culture Filtrates

Assessment of resistance and tolerance of in vitro-propagated banana plants to burrowing nematode, Radopholus similis

1999 ◽  
Vol 39 (7) ◽  
pp. 891 ◽  
Author(s):  
J. M. Stanton
Keyword(s):  
Life Cycle ◽  
Resistance Mechanism ◽  
Radopholus Similis ◽  
Severe Damage ◽  
Different Ages ◽  
Burrowing Nematode

Summary. In vitro-propagated banana plants cv. Goldfinger were not resistant to Radopholus similis unless they were at least 28 weeks old at inoculation. By contrast, a Pisang jari buaya clone and SH-3142 expressed resistance when inoculated from 12 and 8 weeks of age respectively. Fewer nematodes were recovered from older plants of Goldfinger than from Cavendish 3 weeks after inoculation (i.e. before a life cycle could be completed). This suggests that the resistance mechanism of Goldfinger involves reduction in both penetration and reproduction by nematodes. Comparison of recovery of nematodes following inoculation of plants at different ages showed that resistance assays should use plants which are at least 28 weeks old. Also, plants should be at least 28 weeks old when establishing a plantation to reduce the chance of severe damage by high nematode densities. Goldfinger was more tolerant to R. similis than was Cavendish when supporting the same number of nematodes.

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