Banca de DEFESA: JÚLIA PIMENTA PEREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JÚLIA PIMENTA PEREIRA
DATE: 07/10/2022
TIME: 09:00
LOCAL: Sala virtual através do link https: meet.google.com/voz-aexm-sdf
TITLE:

COINOCULAÇÃO DE AZOSPIRILLUM E FUNGOS MICORRÍZICOS ARBUSCULARES NO DESENVOLVIMENTO DA UROCHLOA BRIZANTHA PARA USO EM PROCESSO DE RECUPERAÇÃO DE ÁREAS DEGRADADAS POR ATIVIDADE AGRÍCOLA

KEY WORDS:

Brachiaria; pastures; Azospirillum; mycorrhizae; brizantha; Arbuscular Mycorrhizal Fungi.

PAGES: 65
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Microbiologia e Bioquímica do Solo
SUMMARY:

Brazil is the largest exporter of beef in the world and has pastures as a food base for all production in the country. However, the country has about 70 million hectares of pastures with some level of degradation and it is necessary for the livestock sector to make use of technologies that aim at the recovery of these areas and the more efficient management of pastures. Studies have been carried out with the objective of identifying microorganisms that have symbiosis with grasses and promote better plant development and increased production while contributing to soil quality and reduced degradation. One of the main obstacles to the efficiency of U. brizantha seed inoculation is the low quality of the seeds. Usually, seed lots of this genus have a large amount of clods, stones, insects and other contaminants that bring a large microbial load and negatively influence the germination process and the efficiency of inoculation of these seeds with beneficial microorganisms, which is another obstacle to be addressed. overcome when it comes to establishing pasture in good condition. Therefore, the initial objectives are to develop a protocol for cleaning and disinfesting seeds Urochloa brizantha cv. Marandu that increase the efficiency of inoculation of seeds with growth-promoting microorganisms, the molecular characterization of Azospirillum strains and the evaluation of the influence of the symbiosis between Arbuscular Mycorrhizal Fungi (AMF) and Azospirillum sp. in the initial development of Capim-Marandu. Seed cleaning and disinfestation protocols, obtained by 2 different suppliers, with different concentrations of sodium hypochlorite (NaClO) and different times of scarification in concentrated sulfuric acid (H2SO4) were tested in order to obtain the best concentration and combination that meet the premises of U. brizantha seed purification; do not compromise its physical structure and enable inoculation with the microorganisms of interest. Germination and seed purity tests were applied. In all, 14 strains of Azospirillum were submitted to molecular techniques based on genotypic analysis of DNA and PCR BOX and ERIC PCR for the identification and differentiation of microorganisms. The tests of the influence of the inoculation of Azospirillum strains and AMFs on the initial development of U. brizantha were carried out at the Laboratory of Microbial Ecology - Nucleus of Applied Biology (NBA), belonging to Embrapa Milho e Sorgo, under greenhouse conditions using soil and substrate containing vermiculite and sand (2:1) focusing on the establishment of symbioses. 03 strains of Azospirillum sp., 2 strains of AMF, the synergy between them were tested. The experimental design was in completely randomized blocks (DBC), in a 4x3x4 factorial scheme. Evaluations were started 90 days after planting. The parameters evaluated are leaf area; root area; number of tillers; fresh weight, dry weight and root and shoot dry weight; rate of colonization of fungi and bacteria in the root system. It was possible to infer that the concentration of 4% of NaClO followed by washing the seeds in 92.8% alcohol provided the lowest growth of microorganisms in the seeds after cleaning and the time of 15 minutes of immersion of seeds in H2SO4 provided an improvement in germination of the seeds. Of the 14 Azospirillum strains, 11 were identified, one of them from the Pseudomonas genus, proving the importance of molecular and genotypic identification of microorganisms. BOX PCR and ERIC PCR techniques contributed significantly to the intraspecific differentiation of Azospirillum strains.

BANKING MEMBERS:
Externo à Instituição - FREDERICK MENDES AGUIAR
Presidente - 371.206.387-34 - IVANILDO EVODIO MARRIEL - EMBRAPA
Externa ao Programa - 1583887 - NADIA NARDELY LACERDA DURAES PARRELLA