Banca de DEFESA: TACIANA FERREIRA DOS SANTOS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : TACIANA FERREIRA DOS SANTOS
DATE: 24/02/2023
TIME: 09:00
LOCAL: Predio da Pós-Graduação, Sala 4
TITLE:

M

MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF FUNGAL SPECIES ASSOCIATED WITH PLANTS OF THE ORCHIDACEAE FAMILY

KEY WORDS:

CColletotrichum, Fusarium, Neopestalotiopsis, Pseudopestalotiopsis, Phylogeny, Orchid.

PAGES: 118
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Fitopatologia
SUMMARY:

Floriculture is one of the fastest growing agribusiness segments in Brazil, especially the tropical flower market, which is favored by the climatic conditions of the different regions of the country, with emphasis on the northeast region. Within this sector, the production of orchids represents a type of trade in increasing expansion in the national market and this is due to the diversity, beauty of its flowers and its easy cultivation. However, despite the progress, orchid culture has been limited by several factors, among which is the occurrence of diseases, especially those of fungal origin. Knowing the etiological agent is essential for the success, durability and implementation of control measures. Therefore, the objective of the present work was to identify species of fungi associated with orchids through morphocultural and phylogenetic characteristics. The isolates were obtained from native orchids or from commercial plantations showing typical symptoms of diseases with fungal etiology. Subsequently, morphological and cultural studies and pathogenicity tests were carried out in asymptomatic plants belonging to different genera of the Orchidaceae family, followed by DNA extraction and amplification of partial sequences of the glyceraldehyde3-phosphate dehydrogenase (GAPDH) genes. , translation elongation factor 1-α (TEF-1α) and second major RNA polymerase II subunit (RPB2). A total of 80 isolates were obtained, 57 belonging to the genus Colletotrichum, 12 to Fusarium and 11 to pestalotioid fungi. Of these, 11 isolates of Colletotrichum, 5 of Fusarium and 5 of pestalotioid fungi were destined for phylogenetic studies. Colletotrichum cultures showed mycelium varying between shades of gray, yellow and white, with hyaline, non-septate, straight-cylindrical conidia and rounded ends. The Fusarium isolates produced mycelium in shades of white, pink or purple, with hyaline macro and microconidia. While the pestalotioid fungi formed purely white colonies or with an orange reverse, cottony and conidia presenting 2 to 3 apical appendages and a basal appendage. The observation of the morphological and cultural characteristics, together with the phylogenetic analysis of the GAPDH gene, could group the Colletotrichum isolates into the complexes C. gloeosporioides, C. orquidearum, C. gigasporum and C. dracaenophilum; The Fusarium isolates were grouped with species of the F. incarnatum–equiseti complex, F. fujikuroi and F. oxysporum, based on the phylogeny of the partial sequences of the TEF-1α and RPB2 genes. While the pestalotioid fungi clustered with Neopestalotiopsis and Pseudopestalotiopsis species through TEF-1α phylogenetic analysis.

BANKING MEMBERS:
Externo(a) à Instituição - ANA FRANCISCA TIBÚRCIA AMORIM FERREIRA E FERREIRA - UFAM
Presidente - 1546023 - IRAILDES PEREIRA ASSUNCAO
Externo(a) ao Programa - 1997483 - JAQUELINE FIGUEREDO DE OLIVEIRA COSTA
Externo(a) ao Programa - 1121083 - MARIA DE FATIMA SILVA MUNIZ
Interno(a) - 2149632 - SARAH JACQUELINE CAVALCANTI DA SILVA