Selection of Trichoderma spp. strains for the control of Sclerotinia sclerotiorum in soybean

Abstract

-The objective of this work was to evaluate, in vitro and in vivo, the potential of Trichoderma spp. strains to control Sclerotinia sclerotiorum in soybeans (Glycine max) and to perform the molecular identification of the best performing strains. The effect of 120 strains of Trichoderma spp. on the viability of S. sclerotiorum sclerotia was evaluated in vitro through immersion in suspension of conidia from the antagonists and plating in culture medium. The best performing strains were evaluated in vivo, in a greenhouse, for control of the pathogen inoculated on 'Pintado' soybean seeds and plants. Of the 120 strains tested in vitro, 22 strains of Trichoderma spp. caused 100% inhibition of sclerotia germination. In the greenhouse, five strains inhibited the negative effect of the pathogen on seed germination and two strains increased in up to 67% plant dry matter. The best performing strains were identified as T. koningiopsis (3 strains), T. asperelloides (3), T. atroviride (2), and T. virens (1). Trichoderma strains are able to protect soybean plants from the harmful effect of S. sclerotiorum and, at the same time, they can promote the growth of the aerial part in greenhouse conditions. Index terms: Glycine max, biological control, DNA sequencing, sclerotia, white mold. Termos para indexação: Glycine max, controle biológico, sequenciamento de DNA, escleródios, mofo branco. Seleção de estirpes de

Phylogenetic Diversity of Trichoderma Strains and Their Antagonistic Potential against Soil-Borne Pathogens under Stress Conditions

“…Not surprisingly, the sequencing of ITS and/or TEF1 has been extensively studied [ 10 , 31 , 32 , 33 ], reference databases make it possible to submit DNA sequences of environmental isolates and link sequence data to phenotypic data. In particular, molecular DNA markers are employed as a reliable tool to determine the genetic diversity and relationships [ 34 , 35 ].…”

Chemical composition and in vitro inhibitory effects of essential oils from fruit peel of three Citrus species and limonene on mycelial growth of Sclerotinia sclerotiorum

“…The fungus Sclerotinia sclerotiorum, one of the most common pathogens, causes white mold and severe damage to several economically important cultures, such as beans and soybeans, thus, making Brazilian producers face great losses (Haddad et al, 2017). Controlling this disease with the use of chemicals is not only ineffective but also contradictory, since it does not follow the current tendency which searches for ecologically balanced and stable agricultural systems that do not release toxic waste (Milan et al, 2015).…”

Bioprospection of Trichoderma spp. originating from a Cerrado-Caatinga ecotone on Colletotrichum truncatum, in soybean

“…in reducing of pathogen incidence, in which higher or similar results were observed when compared to the commercial product, indicates that the isolates present a high potential of use in the biological control. The results for the variables dry matter and pathogen incidence are in accordance with several studies, in which Trichoderma spp., in focus for Trichoderma koningiopsis Samuels, Suárez & Evans and Trichoderma longibrachiatum Rifai, acts in reducing pathogen incidence, besides acting to promote plant growth (Haddad et al, 2017;Milanesi et al, 2013;Zhang et al, 2015).…”