Banca de DEFESA: BRENO DE HOLANDA ALMEIDA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : BRENO DE HOLANDA ALMEIDA
DATA : 10/07/2026
HORA: 08:00
LOCAL: Central de aulas II
TÍTULO:

Ecophysiological and survival responses of Trichoderma spp. and management of Fusarium rot in melon

PALAVRAS-CHAVES:

I: Biological control, fungal resilience, soil conditions, chlamydospores, agricultural bioinoculant

II: Postharvest, Phytopathogens, Phytoregulators, Antioxidant defenses.

PÁGINAS: 64
RESUMO:

I: The genus Trichoderma is widely used in agriculture due to its ecological versatility, rapid colonization, and multiple mechanisms of action. This study aimed to characterize the growth and physiological responses of six Trichoderma isolates under abiotic conditions (pH, salinity, and temperature). Experiments were conducted in a completely randomized design with five replicates. The experiment was repeated. The isolates evaluated were T. harzianum IBLF006, T. asperellum URM 5911 and BV-10, T. endophyticum IBCB 56/12, T. longibrachiatum, and T. asperelloides MMBF 94/17. The effects of pH (1 to 11), salinity (NaCl, 0 to 1000 mM), and temperature (5 to 50 °C) were evaluated over seven days. After the initial incubation (seven days), isolates were re-incubated at 28 °C for another seven days. No significant differences were observed between experiments, the data were combined and subjected to regression analysis. The isolates grew between pH 2 and 10, with inhibition at pH 1 and 11, and optimal values ranging from 5.1 to 5.8. Fungal growth was constant up to 500 mM NaCl, decreasing above 750 mM. The EC₅₀ values ranged from 746.85 to 1035.10 mM, with no complete inhibition at the tested concentrations. Growth occurred between 10 and 35 °C, with optimal values around 23 to 24 °C. No growth was detected at 5, 40, 45, or 50 °C; however, some isolates recovered their growth and developed chlamydospores after re-incubation at 28 °C. This study demonstrates the physiological plasticity of Trichoderma, which can grow across wide pH and temperature ranges and exhibits high salinity tolerance

II: Brazil is a leading producer and exporter of Galia melon (Cucumis melo L.), a variety renowned for its exceptional sensory qualities. However, postharvest diseases caused by Fusarium spp. lead to significant economic losses, estimated at up to US$22 million annually. The current reliance on fungicides, such as Imazalil, is unsustainable due to regulatory restrictions and the increasing fungal resistance to current chemistry, which calls for the development of alternative control strategies. In this study, we investigated the effectiveness of thermotherapy combined with ripening phytoregulators for managing rots caused by F. falciforme and F. sulawesiense in Galia melons. Inoculated fruits underwent eight different treatments [Mock (control), HWT (hot water treatment), 1-MCP (1-methylcyclopropene), HWT + 1-MCP, GA (gibberellin), HWT + GA, GRAD (Graduate A+®), and HWT + GRAD] and were stored for 20 days at 10 ± 2°C. We evaluated disease severity, melon fruit physicochemical parameters, and the activity of plant defense enzymes. Most treatments significantly reduced rot severity compared to the control. Notably, Graduate A+® achieved up to a 72.9% reduction, and its efficacy was enhanced when combined with thermotherapy. Furthermore, 1-methylcyclopropene (1-MCP) treatment, alone and with thermotherapy, preserved postharvest quality and boosted defense-related enzyme activity. These findings suggest that the combination of thermotherapy and 1-MCP offers a promising, sustainable, and effective strategy for managing Fusarium rot in Galia melons destined for export.

MEMBROS DA BANCA:
Interna - 2578315 - JAILMA SUERDA SILVA DE LIMA
Interna - 1544411 - MARCIA MICHELLE DE QUEIROZ AMBROSIO
Externo à Instituição - CÉSAR JÚNIOR BUENO
Externo à Instituição - FRANCISCO ROMÁRIO ANDRADE FIGUEIREDO
Externo à Instituição - Washington da Silva