Banca de DEFESA: LARISSA MAIA DE OLIVEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE: LARISSA MAIA DE OLIVEIRA
DATA: 28/01/2022
HORA: 08:00
LOCAL: Via Google Meet
TÍTULO:

ENDOPHYTIC FUNGI AND RHIZOBACTERIA: BENEFICIAL EFFECTS ON PLANTS

PALAVRAS-CHAVES:

Keywords: Antimicrobial activity; Volatile organic compounds; Endophytic fungi; Induratia sp.; ITS; Rpb-2; Tub; Pseudomonas; Essential nutrients; 16s rDNA; Bacterial root association.

PÁGINAS: 147
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitossanidade
ESPECIALIDADE: Fitopatologia
RESUMO:

The public interest in sustainable agriculture reinvigorated scientific research on beneficial microorganisms. These microorganisms may improve plant growth by exerting essential functions in soil fertility, plant nutrition and health. The increase in the number of biological products in the world market depicts the importance of beneficial microorganisms in biotechnology. However, the development of new and more specific products demands further research. In the first part of this study, six strains of the endophytic fungus Induratia sp. were isolated and identified by using molecular phylogenetic analyses. These Induratia strains were able to produce volatile organic compounds (VOCs) with antimicrobial activity against Phytophthora sp., Rhizoctonia solani, Botrytis cinerea, Colletotrichum lindemuthianum, Sclerotinia sclerotiorum and Fusarium verticilioides. The Induratia strains produced 17 different VOCs as determined by solid-phase microextraction followed by gas chromatography-mass spectrometry (SPME-GCMS). Strain FTB, identified as I. coffeana has shown the highest inhibition against most pathogens. In a subsequent part of the research, strain FTB was further developed into a product to control B. cinerea in hermetically closed boxes of strawberry, where it was shown to increase the shelf life of the fruits by at least 5 days. A patent filing application for a formulated product containing strain FTB on millet grains was submitted to the National Institute of Industrial Property (INPI) and it was registered under number BR 10 2021 001666 3. In the final part of this work, we exploited the functional diversity of the bacteria from the rhizosphere of faba bean, oat, oilseed rape, wheat, and also from bare fallow soil. A total of 138 bacterial strains were obtained and identified by sequencing a fragment of the16S rDNA gene. A total of 12 genera were identified: Pseudomonas sp., Stenotrophomonas sp., Comamonas sp., Arthrobacter sp., Agromyces sp., Rhodococcus sp., Streptomyces sp., Serratia sp., Lelliotia sp., Paenisporosarcina sp. The most common were Pseudomonas (44.2%) and Stenotrophomonas (23.2%). Their capacity to solubilise phosphorus (P) from aluminium phosphate, tricalcium phosphate and iron phosphate, to mineralise phytate, solubilise potassium (K), to produce siderophores, hydrolise nitrate and inhibit Fusarium graminearum was assayed in vitro. The most common plant growth promotion (PGP) activity was represented by P solubilisation from aluminium phosphate, followed by K solubilisation. Bacterial isolates displaying iron phosphate phosphate solubilisation and mineral P solubilisation from phytate were found only in the rhizospheres of oilseed rape and beans. Approximately 68% of the bacterial strains displayed two or more PGP activities. Four selected strains were applied singly or combined on wheat seeds and were shown to significantly increase root and shoot weight in relation to the control in all single applications. However, their performance in combinations was never superior to single strain applications. Several strains have shown potential to be applied as biofertilizers and biocontrol agents and therefore contribute to increase the sustainability of agriculture.

MEMBROS DA BANCA:
Interno - VALTER CRUZ MAGALHÃES - UFLA (Suplente)
Externo à Instituição - TIM H MAUCHLINE - UFLA (Membro)
Externo à Instituição - SARAH DA SILVA COSTA GUIMARÃES - UFLA (Membro)
Externo à Instituição - PHELLIPPE ARTHUR SANTOS MARBACH - UFRB (Suplente)
Presidente - JORGE TEODORO DE SOUZA (Membro)
Externo à Instituição - CARLOS ANTONIO INACIO - UFRRJ (Membro)
Externo à Instituição - AMANDA AZARIAS GUIMARÃES - UFLA (Membro)