Banca de DEFESA: EMILY MESQUITA DA SILVA
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : EMILY MESQUITA DA SILVA
DATA : 28/02/2019
HORA: 09:00
LOCAL: Anfiteatro do DPA-Sala 14
TÍTULO:
The impact of the environmental persistence of Metarhizium on the biological control of tick Rhipicephalus Microplus
PALAVRAS-CHAVES:
entomopathogenic fungus; rhizosphere-competent; cattle tick
PÁGINAS: 66
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
RESUMO:
The use of biological control with entomopathogenic fungi as a strategy in the alternative control of arthropods solidifies through results that prove the efficiency of these microorganisms. However, applications to the field are still challenged by the influence of abiotic factors such as temperature, humidity and UV irradiation. The selection of native isolates may decrease the negative effects caused by abiotic factors, since these fungi tend to be more tolerant to local climate and microbiota. Although the application of entomopathogenic fungi in agriculture is a current strategy of control through registered products, the scenario in livestock farming is not yet a reality. Thus, the present study aimed to evaluate the persistence of a native isolate of Metarhizium anisopliae under natural conditions and the impact on the recovery of Rhipicephalus microplus larvae. In addition, it was possible to analyze the colonization of Brachiaria brizantha roots.Three groups were formed: two control groups: untreated pots (CTR), pots treated with mineral oil-in-water emulsion without fungus (CTROL) and pots treated with fungal suspension based on LCM S04 isolate. Climatic data (ambient temperature, humidity and UV irradiation) were also evaluated. Soil samples were collected for five months after fungal treatment and inoculated in a selective artificial culture medium to analyze the persistence of fungi in the soil. The recovered isolates were subjected to molecular analysis to confirm (or not) the identity of Metarhizium LCM S04. The untreated group exhibited the highest mean of recovered larvae (2596 ± 1103), followed by the control oil group (740 ± 465). The fungus treated group (LCM S04) had only 11 recovered larvae (mean of 1.37 ± 3.88). Five months after treatment, Metarhizium can still be re-isolated from the soil of treated potted grasses. The mean density of Metarhizium colonies in the soil of fungal treated pots ranged from 0.46 × 105 to 1.1 × 105 colony forming units per gram. The sequences of the ef1-α fragments of the recovered isolates demonstrated high similarity with the S04 LCM. The present study addressed, for the first time, the impact of soil persistence on a native entomopathogenic isolate in R. microplus larvae after contact with engorged females under uncontrolled conditions.
MEMBROS DA BANCA:
Externo à Instituição - CAIO MÁRCIO DE OLIVEIRA MONTEIRO - UFG
Externo à Instituição - GISELA LARA DA COSTA - FIOCRUZ
Externo à Instituição - MARIANA GUEDES CAMARGO - UFRRJ
Presidente - 2221855 - PATRICIA SILVA GOLO
Interno - 387922 - VANIA RITA ELIAS PINHEIRO BITTENCOURT