scholarly journals Selection of Trichoderma isolates for biological control of Sclerotinia minor and S. sclerotiorum in lettuce

2016 ◽  
Vol 42 (3) ◽  
pp. 216-221 ◽  
Author(s):  
Luciana Mecatti Elias ◽  
Manuel Victor P. F. Domingues ◽  
Karina Elaine de Moura ◽  
Ricardo Harakava ◽  
Flávia Rodrigues Alves Patricio
Keyword(s):  
Biological Control ◽  
Agar Medium ◽  
Sclerotinia Minor ◽  
Predominant Species ◽  
Laboratory Conditions ◽  
Lettuce Drop ◽  
Lettuce Cultivar ◽  
Trichoderma Isolates ◽  
Selection Of

ABSTRACT Lettuce drop is one of the most important and difficult-to-control diseases affecting lettuce in Brazil and worldwide. This study was carried out to select Trichoderma isolates antagonistic to Sclerotinia minor and S. sclerotiorum, aiming to develop biological control for this pathosystem in Brazil. Thirty-one Trichoderma isolates were obtained with the use of baits and were tested under laboratory conditions for their ability to control S. minor and S. sclerotiorum in seedlings of lettuce cultivar Tainá cultured in Petri dishes containing water-agar medium. Subsequently, four isolates effective for control and showing high sporulation under laboratory conditions were evaluated in greenhouse in two experiments carried out with both pathogens in lettuce seedlings of the same cultivar. Twenty-two isolates showed ability to control S. minor and S. sclerotiorum in the in vitro experiments. The isolates tested under greenhouse conditions, identified as T. asperellum (IBLF 897, IBLF 904 and IBLF 914) and T. asperelloides (IBLF 908), reduced lettuce drop of seedlings caused by both pathogens but were more effective against S. minor. Biological control is a promising technology for the management of lettuce drop, especially because S. minor is the predominant species in infested lettuce fields in Brazil.

scholarly journals Compatibility of Trichoderma isolates with pesticides used in lettuce crop

2018 ◽  
Vol 44 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Micaele Aparecida Franco da Silva ◽  
Karina Elaine de Moura ◽  
Kamila Ellen de Moura ◽  
Denise Salomão ◽  
Flávia Rodrigues Alves Patricio
Keyword(s):  
Biological Control ◽  
Mycelial Growth ◽  
Culture Medium ◽  
Conidial Germination ◽  
The Other ◽  
Trichoderma Asperellum ◽  
Sclerotinia Minor ◽  
Other Hand ◽  
Lettuce Drop ◽  
Trichoderma Isolates

ABSTRACT Lettuce drop, caused by Sclerotinia minor and S. sclerotiorum, is one of the most important diseases that affect lettuce crop in Brazil. In previous studies, isolates of Trichoderma asperellum (IBLF 897, IBLF 904 and IBLF 914) and T. asperelloides (IBLF 908) were selected for the biocontrol of this disease. In this subsequent study, the compatibility of these isolates with pesticides used in lettuce crop in Brazil was evaluated. Initially, the mycelial growth of isolates was evaluated in culture medium plus pesticides. Then, the effect of pesticides on the parasitism of T. asperelloides isolate IBLF 914 in baits and sclerotia of S. minor and S. sclerotiorum, as well as on the survival of lettuce seedlings, was evaluated in gerboxes after application on baits and sclerotia of the antagonist with pesticides at their respective commercial doses. The fungicides pencycuron and mandipropamid and the insecticide imidacloprid did not affect the mycelial growth of Trichoderma isolates. The fungicide iprodione did not affect the mycelial growth of T. asperellum isolates. but the isolate of T. asperelloides was sensitive from the concentration of 10 µg.L-1 fungicide. Procymidone reduced the mycelial growth of Trichoderma isolates from the concentration of 10 µg.L-1 fungicide, and azoxystrobin reduced the conidial germination of the isolates of the antagonist, showing LD50 between 0.36 and 0.42 µg.L-1 fungicide. On the other hand, in the experiment carried out in “gerboxes”, none of the pesticides reduced the parasitism of baits and sclerotia or reduced the control of S. minor and S. sclerotiorum in lettuce seedlings. Results indicate that the biological control of lettuce drop with T. asperelum isolate IBLF 914 can be compatible with the remaining phytosanitary treatments used in lettuce crop.

scholarly journals Selection of antagonists for biocontrol of Xanthomonas euvesicatoria

2020 ◽  
pp. 181-189
Author(s):  
Ivana Pajcin ◽  
Vanja Vlajkov ◽  
Dragoljub Cvetkovic ◽  
Maja Ignjatov ◽  
Mila Grahovac ◽  
...  
Keyword(s):  
Biological Control ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Bacterial Spot ◽  
Cultivation Medium ◽  
Microbial Strains ◽  
Xanthomonas Euvesicatoria ◽  
Selection Of

Xanthomonas euvesicatoria is a worldwide causer of pepper bacterial spot, a bacterial plant disease responsible for massive losses of fresh pepper fruits. Considering the current problems in management of bacterial plant diseases, biological control using antagonistic microbial strains with high potential for plant pathogens suppression emerges as a possible solution. The aim of this study was to select suitable antagonists for suppression of X. euvesicatoria among the bacteria, yeast and fungi from the genera Pseudomonas, Lactobacillus, Saccharomyces and Trichoderma, based on in vitro antimicrobial activity testing using the diffusion disc method. The results of this study have revealed that cultivation broth samples of the antagonists Lactobacillus MK3 and Trichoderma reseii QM 9414, as well as supernatant samples of the antagonist Pseudomonas aeruginosa I128, have showed significant potential to be applied in biological control of X. euvesicatoria. Further research would be required to formulate suitable cultivation medium and optimize bioprocess conditions for production of the proposed pepper bacterial spot biocontrol agents.

scholarly journals Selection of endophytic fungi from comfrey (Symphytum officinale L.) for in vitro biological control of the phytopathogen Sclerotinia sclerotiorum (Lib.)

2009 ◽  
Vol 40 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Rafaeli Rocha ◽  
Daniela Eleutério da Luz ◽  
Cibelle Engels ◽  
Sônia Alvim Veiga Pileggi ◽  
David de Souza Jaccoud Filho ◽  
...  
Keyword(s):  
Biological Control ◽  
Sclerotinia Sclerotiorum ◽  
Endophytic Fungi ◽  
Symphytum Officinale ◽  
Selection Of

scholarly journals Impact of Trichoderma sp. on the Development of Heterobasidion Annosum in Decayed Understory Picea Abies Stumps

2017 ◽  
Vol 71 (1-2) ◽  
pp. 52-56
Author(s):  
Kristīne Kenigsvalde ◽  
Dina Nitiša ◽  
Dace Saulīte ◽  
Kari Korhonen ◽  
Līvija Vulfa ◽  
...  
Keyword(s):  
Biological Control ◽  
Field Studies ◽  
Antagonistic Effect ◽  
Heterobasidion Annosum ◽  
Economic Losses ◽  
Biological Control Agents ◽  
Trichoderma Sp ◽  
The Impact ◽  
Trichoderma Isolates

Abstract Heterobasidion annosum (Fr.) Bref. s.l. causes significant economic losses in conifer forests. Therefore, to reduce the spread of the infection surfaces of freshly cut conifer, stumps are commonly treated with biological control agents. Trichoderma sp. shows very strong antagonistic effect against H. annosum in vitro, but relatively few field studies have been conducted. Moreover, most of previous studies examined the impact of Trichoderma sp. on H. annosum in healthy conifer stumps. The aim of our work was to evaluate the effect of Trichoderma sp. against H. annosum in already decayed understory spruce stumps. In total, 75 decayed spruce stumps were surveyed. Part of the spruce stumps were left as a control, and the others were treated with one of two Trichoderma isolates (T472 and T945) belonging to two different species: T. viridescens and T. viride. The occurrence of H. annosum was evaluated 3 and 12 months after treatment. The main results were that the area of previously healthy wood occupied by H. annosum was larger in control stumps in comparison with treated stumps, but the differences were not statistically significant.

scholarly journals Towards the Biological Control of Devastating Forest Pathogens from the Genus Armillaria

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 1013 ◽  
Author(s):  
Liqiong Chen ◽  
Bettina Bóka ◽  
Orsolya Kedves ◽  
Viktor Dávid Nagy ◽  
Attila Szűcs ◽  
...  
Keyword(s):  
Biological Control ◽  
Plant Growth ◽  
Soil Conditions ◽  
Spruce Forests ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Trichoderma Isolates ◽  
Armillaria Species ◽  
Oak Seedlings

Research Highlights: A large scale effort to screen, characterize, and select Trichoderma strains with the potential to antagonize Armillaria species revealed promising candidates for field applications. Background and Objectives: Armillaria species are among the economically most relevant soilborne tree pathogens causing devastating root diseases worldwide. Biocontrol agents are environment-friendly alternatives to chemicals in restraining the spread of Armillaria in forest soils. Trichoderma species may efficiently employ diverse antagonistic mechanisms against fungal plant pathogens. The aim of this paper is to isolate indigenous Trichoderma strains from healthy and Armillaria-damaged forests, characterize them, screen their biocontrol properties, and test selected strains under field conditions. Materials and Methods: Armillaria and Trichoderma isolates were collected from soil samples of a damaged Hungarian oak and healthy Austrian spruce forests and identified to the species level. In vitro antagonism experiments were performed to determine the potential of the Trichoderma isolates to control Armillaria species. Selected biocontrol candidates were screened for extracellular enzyme production and plant growth-promoting traits. A field experiment was carried out by applying two selected Trichoderma strains on two-year-old European Turkey oak seedlings planted in a forest area heavily overtaken by the rhizomorphs of numerous Armillaria colonies. Results: Although A. cepistipes and A. ostoyae were found in the Austrian spruce forests, A. mellea and A. gallica clones dominated the Hungarian oak stand. A total of 64 Trichoderma isolates belonging to 14 species were recovered. Several Trichoderma strains exhibited in vitro antagonistic abilities towards Armillaria species and produced siderophores and indole-3-acetic acid. Oak seedlings treated with T. virens and T. atrobrunneum displayed better survival under harsh soil conditions than the untreated controls. Conclusions: Selected native Trichoderma strains, associated with Armillaria rhizomorphs, which may also have plant growth promoting properties, are potential antagonists of Armillaria spp., and such abilities can be exploited in the biological control of Armillaria root rot.

scholarly journals Molecular Characterization and Pathogenicity of Trichoderma Isolates to Meloidogyne javanica

2021 ◽  
Author(s):  
Ricardo R. Balardin ◽  
Cristiano Bellé ◽  
Daiane Dalla Nora ◽  
Rodrigo F. Ramos ◽  
José Carlos V. Rodrigues ◽  
...  
Keyword(s):  
Biological Control ◽  
Molecular Characterization ◽  
Biological Control Agent ◽  
Meloidogyne Javanica ◽  
Control Agent ◽  
High Potential ◽  
Wide Range ◽  
Elisa Plate ◽  
Trichoderma Isolates

Nematodes are considered a serious problem for agriculture. Nematodes of the Meloidogyne genus can attack a wide range of plants, needing different management methods to decrease its population. Fungi from the Trichoderma genus has been related to have potential as biological control agents. However, before an organism is used as biological control agent, first it is necessary to prospect, characterize and test its potential as biocontrol agent, so the objective of this work was to characterize and test fungi isolates of the Trichoderma genus to control M. javanica. We obtained forty isolate to carry out this experiment. We extracted the DNA of each isolate to discover which species we were testing, by doing a PCR and sequencing. We tested in vitro their parasitism effect using ELISA plate. Also, we extracted their filtrate to see if their metabolites have potential to reduce nematode population by showing a high mortality or inhibiting hatching. The results confirmed the high potential of the fungi of Trichoderma genus as a biological agent to control Meloidogyne javanica.

Evaluation of entomopathogenic fungi by larval and adult immersion method v1

2021 ◽  
Author(s):  
Lissette Torres-Torres ◽  
Carlos Espinel-Correal ◽  
Adriana Santos-Díaz
Keyword(s):  
Biological Control ◽  
Pest Management ◽  
Entomopathogenic Fungi ◽  
Biological Control Agent ◽  
Control Agent ◽  
Fungal Species ◽  
Immersion Method ◽  
Selection Of

The search for commercially viable entomopathogenic fungi for use in integrated pest management programs involves several steps. Fungal species must first be obtained from diseased insects or the environment and identified. Then, they must be evaluated under laboratory conditions to identify the most promising candidates. Because of that, bioassays must be repeatable and reliable to determine accurate pathogenicity or virulence. Variability in results may be caused by the variation in the components of an assay. However, the availability of a standardized bioassay is limited. Few reports detail the methods used to develop bioassays for a specific purpose and, without these details, it is difficult to develop bioassay methodologies suitable to evaluate the fungus-host relationship. We described a protocol based on the immersion method to evaluate entomopathogenic fungi (larval and adult stages), that can be reproduced to reduce variability. This protocol can be used in several stages of biopesticide development: selection of the biological control agent, characterization of the microorganism, formulation compatibility, and in vitro evaluation of efficacy.

Selection of strains of Epicoccum purpurascens for tolerance to fungicides and improved biocontrol of Sclerotinia sclerotiorum

1990 ◽  
Vol 36 (11) ◽  
pp. 754-759 ◽  
Author(s):  
Ting Zhou ◽  
R. D. Reeleder
Keyword(s):  
Biological Control ◽  
Key Words ◽  
Sclerotinia Sclerotiorum ◽  
Fungicide Resistance ◽  
White Mold ◽  
Wild Type ◽  
Type Isolate ◽  
Type Strains ◽  
Selection Of

A wild-type isolate of Epicoccum purpurascens was exposed to shortwave ultraviolet light. One of the resulting cultures (M-20-A) was grown on media amended with the fungicides iprodione or vinclozolin and fungicide-tolerant strains were obtained. Several comparisons were made between new strains and the wild type. Sporulation was improved compared with the wild type. Strains varied in their tolerance to iprodione and vinclozolin but were not tolerant to the fungicide benomyl. Strains R4000, 16-B, and 7-A inhibited Sclerotinia sclerotiorum in vitro more than either the wild type or M-20-A, and exhibited improved control of white mold of bean in the greenhouse compared with M-20-A. Key words: biological control, fungicide resistance, white mold, iprodione, vinclozolin.

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