Antifungal potential of crude extracts of Trichoderma spp.

Abstract

Antibiosis is the mechanism by which certain microorganisms respond to the presence of others, secreting compounds or metabolites capable of inhibiting or impeding their development. The crude extract of Trichoderma contains a mixture of secondary compounds, which may show antibiotic effect, and has been used for the prospect of this fungus for biological control and other industrial purposes. Faced with the increasing demand of agriculture for ecologically compatible alternatives for the management of diseases, this work aimed to investigate the spectrum of action of NonVolatile Metabolites (NVMs) of Trichoderma isolates against different plant pathogenic fungi. The antagonistic potential of NVMs was evaluated through the incorporation method of the filtered liquid extract in PDA medium. The assays showed that all the NVMs produced inhibited the fungus Sclerotinia sclerotiorum similarly. On the other hand, strains CEN1245 and CEN1274, both belonging to the species Trichoderma brevicompactum, showed broad spectrum against Sclerotium rolfsii, Colletotrichum gloesporioides, Verticillium dahliae, Fusarium oxysporum and Cylindrocladium sp. The present study describes isolates producing non-volatile metabolites with broad spectrum of antifungal action, as well as pathogen-specific. The Trichoderma spp. NVMs obtained from different soil samples cultivated with vegetables, cassava and maize were efficient in inhibiting plant pathogenic fungi belonging to other patossystems, such as forest or fruit, which could increase their potential application in biological control of plant diseases. In addition, these antagonistic fungi should be studied in greater depth for the identification of bioactive molecules of industrial interest or in commercial formulations of products for biological control of plant pathogens.Keywords: secondary metabolites, antagonism, inhibition of mycelial growth, plant pathogenic fungi. Potencial antifúngico de extratos brutos de Trichoderma spp.Resumo: Antibiose é um mecanismo pelo qual certos microrganismos respondem à presença de outros, secretando compostos ou metabólitos capazes de inibir ou impedir o seu desenvolvimento. O extrato bruto de Trichoderma contém uma mistura de compostos secundários e tem sido utilizado na prospecção deste fungo para o controle biológico e demais fins industriais. Diante da crescente demanda da agricultura por alternativas ecologicamente compatíveis para o manejo de doenças, este trabalho teve como objetivo investigar o espectro de ação de Metabólitos Não Voláteis (MNVs), produzidos por isolados de Trichoderma, contra diferentes fungos fitopatogênicos. O potencial antagônico dos MNVs foi avaliado através do método de incorporação do extrato líquido filtrado em meio BDA. Os ensaios mostraram que todos os MNVs produzidos inibiram de forma semelhante o fungo Sclerotinia sclerotiorum. Por outro lado, os isolados CEN1245 e CEN1274, ambos Trichoderma brevicompactum, mostraram um amplo espectro de ação, atuando contra Sclerotium rolfsii, Colletotrichum gloespori...

BIOCONTROL OF TEAK CANKER CAUSED BY Lasiodiplodia theobromae

“…Similarly, Adeniyi et al (2013), evaluating the antagonistic effect of T. virens against Lt, from cashew tree inflorescence, showed total inhibition of mycelial growth of the pathogen. In view of the results obtained in this study, there is confirmation that the antagonistic action of Trichoderma isolates is intra-and interspecifically variable, corroborating the findings of Dennis and Webster (1971), Brodeur (2012) and Marques et al (2018).…”

“…Levels of biological control against a target organism are intra and interspecifically variable, and this variation also occurs between isolates of antagonistic microorganisms (Dennis and Webster, 1971;Brodeur, 2012;Marques et al, 2018). In forest plants, some studies have reported satisfactory levels of biocontrol of plant pathogens both in vitro (Marques and Uesugi, 2017;Adeniyi et al, 2013, Briceño et al, 2008, Kupper et al, 2004, Mortuza and Ilag, 1999 and in vivo (Maciel et al, 2017, Sultana andGhaffar, 2010).…”

Characterisation and antifungal activity of extracellular chitinase from a biocontrol fungus, Trichoderma asperellum PQ34

“…Pacheco et al (2016) evaluated the efficacy of six Trichoderma isolates to control sclerotium wilt (S. rolfsii) of common bean (Phaseolus vulgaris) and found that three of them (T. hazianum, T. longibrachiatum and T. reesei) were more efficient in reducing sclerotial germination. Marques et al (2018) isolated two strains CEN1245 and CEN1274, both belonging to the species T. brevicompactum, exhibiting a broad spectrum against S. rolfsii, C. gloesporioides, and the other disease fungi. De la Cruz-quiroz et al (2018) studied in vitro antagonistic activity in dual culture detected that T. asperellum (T2-32) strain displayed the highest capacity of inhibition against Colletotrichum gloeosporioides up to 22.5%.…”

Trichoderma atroviride como controlador biológico de fusariosis de espiga de trigo mediante la reducción del inóculo primario en rastrojo

“…Production of soluble antifungal compounds in liquid medium. This assay followed the methodology of Marques et al (2018) with some modif ications. The different Trichoderma strains were inoculated in flasks containing 50 mL of YES medium (yeast extract, 2%; sacarose, 15%, pH = 6) adding 1 mL of 1 × 10 6 conidia mL -1 suspension.…”