Banca de DEFESA: MARIANA BESSA DE QUEIROZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARIANA BESSA DE QUEIROZ
DATE: 23/02/2022
TIME: 14:00
LOCAL: meet.google.com/mhb-nkyy-txd
TITLE:

Diversity of Arbuscular Mycorrhizal Fungi (Glomeromycota) in lentic and lotic aquatic ecosystems of Rio Grande do Norte, Brazil

KEY WORDS:

Aquatic macrophytes. Depth. Mycorrhiza. Seasonality. Taxonomic inventories.

PAGES: 92
BIG AREA: Ciências Biológicas
AREA: Botânica
SUBÁREA: Taxonomia Vegetal
SPECIALTY: Taxonomia de Criptógamos
SUMMARY:

Arbuscular Mycorrhizal Fungi (AMF) are symbiotic microorganisms from terrestrial and aquatic plant roots. However, lentic and lotic aquatic ecosystems are little explored regarding their occurrence and ecology. Few diversity inventories have documented more than 100 species and ecological studies have tested the influence of
environmental variables on the degree of root colonisation, but the structure of AMF communities under these two conditions and the influence of environmental variables is poorly known. This work objective was to make an inventory of the AMF species in two lentic environments (Carcará and Arituba Lagoons) and two lotic environments (Boa Cica Stream and Pium River) in the municipality of Nísia Floresta, Rio Grande do Norte, Brazil, and evaluate the influence of water and seasonal parameters on species composition, diversity, richness, and sporulation. For this purpose, two samples were taken in the dry (December 2016) and wet (July 2017) periods, removing rhizospheric soils of different species of macrophytes inhabiting depths from 0.02 to 2.72 m. Glomerospores were extracted from 50 g of soil and mounted on slides for taxonomic identification. Species were evaluated for occurrence frequency and relative abundance, being later classified as dominant, common, and rare. Differences in the species composition were tested by Cluster Analysis, ANOSIM, and SIMPER. Diversity was evaluated among different conditions and seasons using rarefaction curves interpolated and extrapolated to Hill numbers. Richness and sporulation were tested in relation to conditions, seasons, and depth by Generalized Linear Models and ANOVA. Eighty-eight species were identified and classified in 5 orders, 11 families, and 21 genera. Sixty-one species occurred in the lentic condition (57 in the Arituba Lagoon and 24 in the Carcará Lagoon) and 55 in the lotic condition (39 in the Boa Cica Stream and 31 in the Pium River). Seventeen species were shared among the four sites. Glomeraceae and Acaulosporaceae were the most representative families in species richness in all lentic and lotic interactions and species abundance in lotic interactions, while the Ambisporaceae family showed high abundance in lentic interactions. Species composition differed significantly between lentic and lotic interactions. Greater Shannon and Simpson diversity were found in the Arituba/Dry interaction to the detriment of lower diversity in Boa Cica/Dry. Lotic interactions did not differ in species richness and glomerospores density but were significantly different from lentic interactions in species richness. The lentic interactions, on the other hand, differentiate among themselves, in higher richness and sporulation found in Arituba Lagoon, which also showed the highest nutrient concentration in sediment. There was a decrease in richness and glomerospores density caused by a depth gradient increase only in Arituba Lagoon; it is possibly related to a mesotrophic trait of this lagoon. This work results bespeak these aquatic ecosystems potencial in harboring high richness of AMF species and suggest that communities composition and species richness are influenced by lentic and lotic condition and also that richness and sporulation vary among lentic environments with different trophic status.

BANKING MEMBERS:
Presidente - 1755051 - BRUNO TOMIO GOTO
Externo à Instituição - FRANCISCO ADRIANO DE SOUZA - EMBRAPA
Externa à Instituição - ROSILAINE CARRENHO - UEM