Toxicity of the insect growth regulator lufenuron on the entomopathogenic fungus Metarhizium anisopliae

Metarhizium anisopliae has been considered a promising alternative with low environmental impacts for the biological control of a variety of insect-pests. Another alternative is the use of biological pesticides such as insect growth regulators, including lufenuron. An assessment of the potential impact of fungicides on M. anisopliae is of critical importance to integrated pest management, permitting the compatible use of this entomopathogen with chemical defensives. Based on this, this study aimed to evaluate the effect of different concentrations of lufenuron on the conidia germination speed of M. anisopliae. Conidia were incubated at 28°C and sampled throughout 12 h. Bayesian analysis showed an inhibition of conidia germination in the presence of 2.0 mg/ml of lufenuron, whereas their compatibility was observed in the concentrations of 1.0 mg/ml and 700 μg/ml. It indicates that in these last two concentrations, the fungicide has no toxicity on M. anisopliae, what suggests that it can be employed in biological-chemical combinations, maintaining viable the fungal inoculums after its application in the field, with a low environmental impact.Key words: Entomopathogen, biological control, vegetative development, biological-chemical combinations

Boto, a class II transposon in Moniliophthora perniciosa, is the first representative of the PIF/Harbinger superfamily in a phytopathogenic fungus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Boto, a class II transposable element, was characterized in the Moniliophthora perniciosa genome. The Boto transposase is highly similar to plant PIF-like transposases that belong to the newest class II superfamily known as PIF/Harbinger. Although Boto shares characteristics with PIF-like elements, other characteristics, such as the transposase intron position, the position and direction of the second ORF, and the footprint, indicate that Boto belongs to a novel family of the PIF/Harbinger superfamily. Southern blot analyses detected 6-12 copies of Boto in C-biotype isolates and a ubiquitous presence among the C- and S-biotypes, as well as a separation in the C-biotype isolates from Bahia State in Brazil in at least two genotypic groups, and a new insertion in the genome of a C-biotype isolate maintained in the laboratory for 6 years. In addition to PCR amplification from a specific insertion site, changes in the Boto hybridization profile after the M. perniciosa sexual cycle and detection of Boto transcripts gave further evidence of Boto activity. As an active family in the genome of M. perniciosa, Boto elements may contribute to genetic variability in this homothallic fungus. This is the first report of a PIF/Harbinger transposon in the genome of a phytopathogenic fungus.1591112125Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)SEAGRI (Secretaria de Agricultura do Estado da Bahia)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP