ABSTRACT
Meloidogyne incognita-javanica representa una limitación de los cultivos agrícolas y es necesario buscar alternativas para su manejo. El presente trabajo tuvo como objetivo evaluar el efecto in vitro del filtrado crudo de Purpureocillium sp. (Cepa UdeA0106) sobre laeclosión de huevos y los estadios juveniles de Meloidogyne spp. Adicionalmente, se evaluaron los medios: caldo extracto de malta (CEM), caldo extracto de levadura (CEL) y caldo papa glucosa (CPG), escogiéndose aquel que no ejerciera daño sobre la morfología de los huevos y permitiera la eclosión de los estadios juveniles. El hongo se multiplicó durante 7 días y fue filtrado. Para establecer su efecto sobre los huevos y estadios J2 de Meloidogyne spp., se probaron concentraciones del filtrado al 100 %, 90 %, 70 %, 50 %, 25 % y 10 %; comparándolas con un control compuesto de estadios J2 en agua destilada estéril (ADE) y CPG. Las variables a evaluar fueron el porcentaje de eclosión e inmovilidad en los J2. La unidad experimental fue la caja de Petri, cada una con 200 huevos/J2, con 5 réplicas de cada tratamiento. Se utilizó un diseño experimental completamente aleatorizado con ANOVA (P = 0,05) y análisis de comparación múltiple de Tukey. Se encontraron diferencias significativas entre todos los tratamientos (P < 0,05) pero el tratamiento correspondiente al filtrado puro (100 %) logró mantener el porcentaje más bajo de eclosión y mayor porcentaje de inmovilidad de los J2 (96,8 %). Las concentraciones al 90 % y 70 % igualmente lograron efectos en los J2, con porcentajes altos de inmovilidad.
Meloidogyne incognita-javanica represents an important threat to the agricultural crops, and it is necessary to seek alternatives for its control. The aim of this research it was to evaluate a crude filtrate from the strain Purpureocillium sp. UdeA0106 in order to establish the in vitro effect on the egg hatching and the immobility of juvenile stages of Meloidogyne spp. The mediums evaluated were malt extract broth (MEB), yeast extract broth (YEB), and potato dextrose broth (PDB), after which it was chosen the one that didn't produce any damages on nematode eggs and allowed the emergence of the larval stages. The fungus was multiplied for 7 days, and then it was filtrated. To evaluate its effect on the eggs and the J2 of Meloidogyne spp., filtrate concentrations were made at 100 %, 90 %, 70 %, 50 %, 25 % and 10 %, contrasting them with a control composed of the J2 stages in sterile distilled water and PDB. The variables evaluated were the percentage of altered eggs and the immobility observed in J2 stages. The experimental unit was the Petri dish, each one containing 200 eggs /J2. Each treatment was replicated 5 times. It was used a completely randomized design, and an ANOVA was performed (P = 0,05) as well as a multiple comparison test (Tukey). Significant differences were found between all treatments (P < 0,05), although the most effective in inhibiting both egg hatching and J2 mobility (96,8 %) were the full strength filtering (100 %). The dilutions at 90 % and 70 %, were able to produce effects with high percentages in the immobility.
ABSTRACT
This study evaluated the effects of destruxin A on Rhipicephalus (Boophilus) microplus females, since this toxin is one of the likely causes of high mortality induced by the entomopathogenic fungus Metarhizium anisopliae in arthropods. Ticks were immersed or inoculated with different concentrations of destruxin A. Despite the doses applied, there were no deaths or significant alterations in oviposition between the groups treated with destruxin A and the control groups. No other external effect caused by destruxin, such as tetanic paralysis, was observed in these engorged female ticks after the treatment.
Este estudo avaliou os efeitos da destruxina A em fêmeas de Rhipicephalus (Boophilus) microplus, uma vez que essa toxina é uma das prováveis causas da alta mortalidade induzida pelo fungo entomopatogênico Metarhizium anisopliae em artrópodes. Os carrapatos foram imersos ou inoculados com diferentes concentrações de destruxina A. Apesar das doses aplicadas, não houve mortes ou alterações significativas de postura entre os grupos tratados com destruxinas A e os grupos controle. Nenhum outro efeito externo provocado pela destruxina A, tal como paralisia tetânica, foi observado nas fêmeas ingurgitadas de carrapato após o tratamento.
Subject(s)
Animals , Female , Depsipeptides/pharmacology , Ixodidae/drug effects , Mycotoxins/pharmacologyABSTRACT
The improvement of techniques of biological control and the use of metabolites produced by microorganisms to obtain products that can be applied in various fields, is getting stronger in face of the undeniable advantages in relation to the models currently in adopted. This review, besides general considerations about the principles and the application of measures of biological control and usage of metabolites produced by microorganisms as sustainable alternatives for the agrochemical segment, among others, reports theexperience lived by the author and the institutions to which she is associated, concerning identification, characterization and development of a biological fungicide resulting from the encapsulation of the fungus Cladosporium cladosporioides (Fres.) de Vries, after proving its bioprotecting action on the quality of the coffee. The possibility of using microorganisms as a source of metabolites obtained from biological extracts, with applications in various fields, is also presented and discussed.
O aprimoramento das técnicas de controle biológico e o aproveitamento de metabólitos produzidos por microrganismos para obtenção de produtos aplicáveis em várias áreas do conhecimento humano, vem se fortalecendo diante de inegáveis vantagens em relação aos modelos hoje adotados. A presente revisão, além de considerações gerais sobre princípios e aplicações de medidas de controle biológico e de aproveitamento de metabólitos produzidos por microrganismos como alternativas de sustentabilidade para o segmento de agroquímicos entre outros, relata a experiência vivenciada pela autora e instituições às quais encontra-se associada com relação à identificação, caracterização e desenvolvimento de um fungicida biológico resultante do encapsulamento do fungo Cladosporium cladosporioides (Fres.) de Vries, após a comprovação de sua ação bioprotetora sobre a qualidade do café. A possibilidade da utilização de microrganismos como fonte de metabólitos obtidos de extratos biológicos, com aplicações em vários setores do conhecimento, também é apresentada e discutida.