Banca de QUALIFICAÇÃO: JOSÉ MAURICIO FAJARDO DA CUNHA
Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.STUDENT : JOSÉ MAURICIO FAJARDO DA CUNHA
DATE: 26/09/2024
TIME: 13:30
LOCAL: Embrapa Agrobiologia
TITLE:
Bioprospecting of Bacillaceae bacteria for the Control of the Etiological Agent of Clubroot in Crucifers.
KEY WORDS:
biological control; bioinsume; Plasmodiophora brassicae, biocontrol products
PAGES: 44
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitotecnia
SPECIALTY: Fisiologia de Plantas Cultivadas
SUMMARY:
The Brassica genus stands out for its food and nutritional importance, being produced by various countries, and comprises a diverse range of species of agro-industrial interest. One of the main production challenges is the presence of phytopathogens, which affect cultivation, crop productivity, and, ultimately, the quality of the final product. One of the most important diseases affecting the genus is clubroot, caused by the protozoan Plasmodiophora brassicae. The main symptom is the formation of galls on the roots, hindering the absorption of water and nutrients, leading to signs similar to water stress and nutritional deficiency, resulting in plant wilting and decline. Clubroot is difficult to control, as the pathogen can persist in the soil for long periods of time. The primary mitigation tools are preventive measures, such as the use of agrochemicals, crop rotation, soil pH adjustment, and sanitization of equipment, though these are not always effective in managing the disease. The use of microorganisms and their by- products as biological control agents stands out as a promising alternative in controlling the protozoan. The goal of this project is to bioprospect bacteria from the Bacillaceae family for the control of the etiological agent of clubroot. In this context, root samples
from cruciferous plants and rhizospheric soil were collected from farms in the mountainous region of the state of Rio de Janeiro, Brazil. The samples were then processed to isolate bacteria of interest and stored in a collection. Since P. brassicae cannot yet be cultured in vitro, the selection of strains with antagonistic potential
against this protozoan will be carried out using an indirect selection method, where isolates of two phytopathogenic fungi (Fusarium oxysporum f. sp. lycopersici and Magnaporthe oryzae) will be used, as they share similarities in cell wall composition and structure with P. brassicae. The effect of the strains on the germination of P.brassicae spores in vitro will also be evaluated. The pre-selected bacterial strains will be
assessed for their impact on the germination rate and root development of cauliflower seeds. Greenhouse trials will be conducted to evaluate both the effect of the pre-selected bacterial strains on reducing the number and size of galls caused by P. brassicae in cauliflower plants, as well as their growth-promoting effect. The strains that show the best results in controlling clubroot in cauliflower will undergo taxonomic identification
through 16S rDNA gene sequencing and multilocus sequence analysis (MLSA), combined with phylogenetic analysis. Physiological activity assays, such as the production of hydrogen cyanide, chitinase, cellulase, protease, and pectinase, will be performed to determine the potential mode(s) of action of these bacterial strains in controlling P. brassicae. It is expected that at least one bacterium with antagonistic activity against the evaluated pathogen will be selected for the development of a future bioproduct.
COMMITTEE MEMBERS:
Presidente - ***.864.458-** - JOSÉ IVO BALDANI - UFRRJ
Interna - ***.210.947-** - MARCIA SOARES VIDAL - EMBRAPA
Interna - 1213072 - MARGARIDA GORETE FERREIRA DO CARMO
Externa à Instituição - MARCIA REED RODRIGUES COELHO - EMBRAPA