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Congresso Brasileiro de Microbiologia 2023
 		Resumo: 1203-1

1203-1

IN VITRO ANTAGONISM OF RHIZOBACTERIA AGAINST Magnaporthe oryzae, A PATHOGEN FUNGUS CAUSING BRUSONE IN RICE PATHOGENS

Autores:
Leandra Gonçalves Franco (UFG - Universidade Federal de Goiás, EMBRAPA - EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA ) ; Vanislene Borges Silva (UFG - Universidade Federal de Goiás, EMBRAPA - EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA ) ; Kassia Lorrany Marques de Paula (UFG - Universidade Federal de Goiás, EMBRAPA - EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA ) ; Juliana de Farias Machado (UFG - Universidade Federal de Goiás, EMBRAPA - EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA ) ; Gabriella Alves Duarte (UFG - Universidade Federal de Goiás, EMBRAPA - EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA ) ; Marta Cristina Corsi de Filippe (EMBRAPA - EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA )

Resumo:
Rice (Oryza sativa) is an important cereal, rich in starch, proteins, lipids, vitamins and minerals, widely consumed. The most destructive rice disease is Blast, caused by the fungus Magnaporthe oryzae, resulting in losses of up to 100% of productivity. Studies with rhizobacteria have shown efficacy in controlling this disease, stimulating plant development and protection. The objective of this work was to evaluate in vitro the potential of bacterial isolates as antagonists to Magnaporthe oryzae. Twelve isolates of rhizobacteria of the genus Pseudomonas sp., Bacillus cereus, B. thuringiensis, Stenotrophomonas maltophilia, S. nitritireducens, Enterobacter hormaechei and Priestia megaterium were used to investigate the antagonism against Brusone. For antagonistic evaluation, different rhizobacteria were used against the fungus M. oryzae in vitro conditions. The analysis involved measuring the mean colony diameter (MCD) of M. oryzae four equal parts and calculating the percentage of mycelial inhibition by the rhizobacteria. Using M. oryzae mycelium discs in Petri dishes containing PDA (Potato Dextrose Ágar), 5µl of bacterial suspension were added at four points, forming a square. For the positive control, only M. oryzae mycelium discs were placed and the plates were incubated at 28°C under constant light. After 7 days of incubation, the DMC was measured and the percentage of inhibition caused by the rhizobacteria was calculated. Data were submitted to statistical tests, including normality test, analysis of variance and Scott Knott test with a significance level of 5%. The software used for the analyzes was SISVAR®. Of the twelve isolates, five presented lower DMC values compared to the control, indicating that there was a greater antagonistic potential. Two of these isolates showed reduced mycelial growth of M. oryzae. This study presents the potential of two rhizobacteria for rice blast suppression studies.

Palavras-chave:
 Sustainable agriculture, beneficial bacteria, disease, biological control


Agência de fomento:
Ministério da Agricultura e Pecuária - MAPA - Brazil