Banca de DEFESA: LAYANE SILVA BARBOSA DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LAYANE SILVA BARBOSA DE SOUZA
DATE: 30/11/2021
TIME: 09:00
LOCAL: Defesa remota pelo Google Meet
TITLE:

Native bacteria from caatinga soils in symbiosis with Mimosa tenuiflora: occurrence and taxonomic positioning

KEY WORDS:

alpha-rhizobia; beta-rhizobia; Mimosa tenuiflora (Willd. Poir.).

PAGES: 80
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SUMMARY:

Biological nitrogen fixation (FBN) is the main input process for this nutrient in natural
ecosystems and in low-input agriculture. Furthermore, the introduction of leguminous
trees inoculated with diazotrophic bacteria can be a strategy for nitrogen acquisition to
recover degraded areas. jurema negra is a legume that occurs widely in several
fragments of caatinga, mainly in areas undergoing regeneration of native vegetation.
This species is capable of forming nodules and acquiring considerable proportions of
its nitrogenous nutrition through symbiosis with rhizobia. However, there is still little
information about the specifics of symbiosis. The objective of this work was to evaluate
the occurrence, characteristics and diversity of microsymbionts of black jurema
naturally established in soils in the semiarid region of Pernambuco. In order to carry
out a representative sampling of the different edaphoclimatic conditions, points were
selected in areas with dense caatinga coverage (with little anthropogenic interference)
and with the main classes of soils occurring in the biome: Argisol, Litholic Neosol,
Quartzarenic Neosol, Regolithic Neosol, Latosol, Luvissol and Planosol. To access the
rhizobian community of the soils, an experiment was carried out in a greenhouse using
black jurema as a bait plant. From the nodules collected in the bait-plant experiment,
391 isolates were obtained, most of them fast growing, with metabolism that acidifies
the culture medium and producing a lot of mucus. As a criterion for authenticating the
rhizobia status of the isolates, the ability to fix nitrogen and form nodules was evaluated
by means of the simultaneous amplification of the symbiotic genes nifH and nodC, and
250 positive isolates were selected by the Duplex-PCR method. The genetic diversity
of the isolates was evaluated by Restriction Analysis of Amplified Ribosomal DNA
(ARDRA) which allowed the formation of two groups, within which 29 subgroups were
formed at 75% similarity. From this grouping, 48 isolates were selected for evaluation
of the genetic profile through BOX PCR and sequencing of 16S rRNA and gyrB genes.
Analyzing the tree based on the 19 isolates with good quality 16S gene sequence, it
was found that the 19 isolates belong to the class of betaproteobacteria belonging to
the genus Paraburkholderia.

BANKING MEMBERS:
Externo à Instituição - JAKSON LEITE
Externo à Instituição - FÁBIO BUENO REIS JÚNIOR
Presidente - 457.055.504-72 - ANA DOLORES SANTIAGO DE FREITAS - UFRPE
Interna - 1929733 - GISELLE GOMES MONTEIRO FRACETTO
Interno - 385061 - MARIO DE ANDRADE LIRA JUNIOR