Banca de DEFESA: GIOVANA SCHNEIDER

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : GIOVANA SCHNEIDER
DATA : 08/05/2026
HORA: 15:00
LOCAL: Sala de reunião e multiusuário PPGASP
TÍTULO:

SCREENING OF ENDOPHYTIC FUNGI FROM CERRADO ANNONACEAE FOR THE CONTROL OF Spodoptera frugiperda  

PALAVRAS-CHAVES:

Endophytes. Annonaceae. Insecticidal Activity.

PÁGINAS: 60
GRANDE ÁREA: Ciências Biológicas
ÁREA: Microbiologia
SUBÁREA: Microbiologia Aplicada
RESUMO:

Endophytic fungi are an important source of bioactive metabolites with potential applications in agriculture. However, little is known about the potential of endophytes from Cerrado plants to control insect pests. Thus, the objective of this study was to select endophytic fungi from Annona coriacea with the potential to cause mortality in Spodoptera frugiperda. To this end, 44 isolates of endophytic fungi were reactivated on solid culture medium and subjected to qualitative tests for the production of proteases, lipases, and chitinases. The selected fungi were then cultured in BD broth under agitation, and the metabolic extract was obtained after liquid-liquid extraction with ethyl acetate. Screening bioassays using 5% ethyl acetate extract (EA 5%) were used to evaluate acute mortality and effects on the larval development of second-instar caterpillars following topical application. The fungi producing the most effective extracts were identified using molecular biology techniques. Finally, the AE5% extracts with the best results were used in new mortality bioassays at different concentrations (5, 10, and 20 mg/mL). Mortality was corrected using the Abbott method and analyzed using generalized linear models (GLM) with a binomial distribution. Dose–response curves, median lethal concentrations (LC₅₀), and survival curves were estimated using the Kaplan–Meier method. The sublethal effect was evaluated through food consumption and calculation of the Deterrence Index, with statistical comparison of the means (p < 0.05). Approximately 14 endophytic isolates produced the evaluated enzymes, and only five were capable of causing acute mortality in S. frugiperda. Of these, the 5% AE extract of Diaporthe spp. (isolates AC 20 and AC 35) containing 20 mg/mL exhibited the highest mortality rate in S. frugiperda (64.7%). These same extracts exhibited the lowest mean lethal concentrations (LC₅₀) (12.65 mg/mL and 12.71 mg/mL) and the fastest action. The highest deterrence rates were observed in Diaporthe sp4. 35 (31.74%), followed by Epicoccum sp1. AC26 (30.73%) and Diaporthe sp2. AC20 (28.39%). Thus, the results led to the selection of Diaporthe sp. 4. AC 35 as the most promising candidate. However, further studies should be conducted to optimize the extraction of secondary metabolites and validate the use of extracts from these fungi for the control of insect pests.

MEMBROS DA BANCA:
Presidente - 118802007 - HILTON MARCELO DE LIMA SOUZA
Interna - 101366004 - MONICA JOSENE BARBOSA PEREIRA
Externa à Instituição - 313.889.812-20 - HILEIA DOS SANTOS BARROSO - IPT-SP