Banca de QUALIFICAÇÃO: JÉSSICA FERREIRA LOURENÇO LEAL

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JÉSSICA FERREIRA LOURENÇO LEAL
DATA : 06/08/2019
HORA: 09:00
LOCAL: Sala 01 - PPGF
TÍTULO:

Role of enzymatic antioxidative system as mechanism of herbicide resistance in Conyza sumatrensis

PALAVRAS-CHAVES:

Conyza sumatrensis; antioxidative enzymes, P450, NTSR resistance

PÁGINAS: 83
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Matologia
RESUMO:

The great challenge of agriculture is the management of weeds resistant to herbicides, and it is worsened where there are biotypes with multiple mechanisms of resistance, such as fleabane, a well-adapted species to the no-tillage system and with great potential for seed dispersal. In Brazil, the species Conyza spp. was reported resistant to five herbicides of different mechanisms of action: glyphosate, paraquat, saflufenacil, 2,4D and diuron. The elucidation of the mechanism of resistance is the first step to mitigate the effect of resistance and the development of a proper weed management plan. The aim of this work is to investigate the activity of antioxidant enzymes and cytochrome P450 (metabolic resistance) of the biotype with multiple resistance compared to the susceptible biotype. The biotype of Conyza sumatrensis to carry out the experiment comes from Assis Chateaubriand-PR and its resistance was confirmed for the herbicides paraquat, saflufenacil, 2,4-D, diuron and glyphosate. Thus, the studies began by investigating the mechanism of resistance of fleabane to the five herbicides, comparing a biotype resistant and the biotype susceptible regarding the metabolization activity of the herbicides by the cytochrome P450, enzymatic antioxidative system: superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) and glutathione S-transferases (GST), the evaluation of oxidative damage, rapid necrosis and storage in the vacuole. Considering the results, propose proactive management strategies for resistant fleabane biotypes, predicting the behavior of other herbicides in the control of the species.

MEMBROS DA BANCA:
Presidente - 1905333 - AROLDO FERREIRA LOPES MACHADO
Externo ao Programa - 3036150 - JUNIOR BORELLA
Externo à Instituição - BIANCA ORTIZ DA SILVA - UFRJ
Externo à Instituição - RICARDO MOREIRA CHALOUB - UFRJ