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

Abstract

Biological control consists of using one organism to attack another that may cause economic damage to crops. Integrated Pest Management (IPM) is a very common strategy. The white mold produced by Sclerotinia sclerotiorum (Lib.) causes considerable damage to bean crops. This fungus is a soil inhabitant, the symptoms of which are characterized by water-soaked lesions covered by a white cottony fungal growth on the soil surface and/or the host plant. Possible biological control agents taken from plants are being investigated as phytopathogen inhibitors. These are endophytic microorganisms that inhabit the intercellular spaces of vegetal tissues and are often responsible for antimicrobial production. The objective of the present study was to select endophytic fungi isolated from comfrey (Symphytum officinale L.) leaves with in vitro antagonist potential against the phytopathogenic fungus S. sclerotiorum. Twelve isolates of endophytic fungi and a pathogenic strain of S. sclerotiorum were used in the challenge method. With the aid of this method, four endophytes with the best antagonistic activity against S. sclerotiorum were selected. Pathogen growth inhibition zones were considered indicative of antibiosis. The percentages of pathogenic mycelia growth were measured both with and without the antagonist, resulting in growth reductions of 46.7% to 50.0% for S. sclerotiorum. These analyses were performed by evaluating the endophytic/pathogenic mycelia growth in mm/day over an eight-day period of antagonistic tests.

Antagonistic Evaluation of Bioactive Metabolite from Endophytic Fungus, Aspergillus flavipes KF671231

“…which showed 85% growth reduction of Sclerotina sclerotiorum in dual culture assay. Rocha et al [18] observed a reduction in the growth rate of S. sclerotiorum ranging from 46.7% to 50.0% by different strains of endophytic fungi isolated from Comfrey (Symphytum officinale L.). Powthong et al [19] studied the fungal extracts of endophytic fungi for antimicrobial activity against Bacillus subtilis and Candida albicans.…”

POPULATION DYNAMICS OF RHIZOBACTERIA AND ITS POTENCY AS A BIOLOGICAL CONTROL AGENT TO CONTROL FUSARIUM DISEASE IN THE NURSERY OF AGARWOOD (Aquailaria malaccensis Lamrk)

“…Level antagonist indicated by the variation of zone inhibition such as weak (<1 cm), moderate (1 to 2 cm) and strong (>2 cm) (Rocha et al, 2009) (Table 3). and each of bacterial isolated power had a different inhibitors (Figure 1).…”

Aplicação de microrganismos endofíticos na agricultura e na produção de substâncias de interesse econômico

“…Entre os esforços necessários, mencionam-se a reprodução no campo dos resultados obtidos em estudos científicos, avaliando-se a influência de fatores externos, como as condições climáticas específicas de cada região e a interação com outras espécies vegetais que ocorrem no mesmo local, entre outros interferentes. É necessário determinar também o modo de ação desses microrganismos, a quantidade de endófitos que deve ser aplicada e, as melhoras formas de entrada no hospedeiro (STURTZ; MATHESON, 1996;BENCHIMOL et al, 2000;RUBINI et al, 2005;OLIVEIRA et al, 2006;SHIOMI et al, 2006;MINHONI, 2008;SILVA et al, 2008;BARRETTI et al, 2009;ROCHA et al, 2009); assim sendo, a continuidade e a intensificação de estudos nessa área é imprescindível.…”