Banca de DEFESA: ATARISSIS MORAIS DIAS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ATARISSIS MORAIS DIAS
DATA : 31/07/2026
HORA: 09:00
LOCAL: Sala 1 do Central de aulas III no campus leste Ufersa e Google Meet (híbrida)
TÍTULO:

SUSTAINABLE MANAGEMENT OF FUSARIUM ROT IN YELLOW MELONS: STRATEGIES BASED ON BIOACTIVE EXTRACTS AND ORGANIC ACIDS

PALAVRAS-CHAVES:

Cucumis melo; post-harvest diseases; Fusarium species; extracts; 139 enzymes; alternative management; biological fungicide

PÁGINAS: 97
RESUMO:

Cucumis melo L. var. inodorus has great economic importance, but rots caused 96 by Fusarium species, including F. falciforme and F. sulawesiense, lead to significant 97 losses, hindering fruit exports. Restrictions on the use of fungicides intensify the search 98 for sustainable alternatives. Therefore, two studies were conducted. The first 99 evaluated the efficacy of bioactive extracts (BEs) as sustainable alternatives to 100 synthetic fungicides for controlling peduncular rot in "Yellow" melon, caused by F. 101 falciforme and F. sulawesiense. Under in vitro conditions, all extracts tested 102 [eucalyptus extract (EUE), pyroligneous extract (PYE), brown propolis extract (BPE), 103 red propolis extract (RPE), and green propolis extract (GPE) demonstrated inhibition, 104 with the highest efficiency observed at a concentration of 8% (v/v). Specifically, PYE 105 and RPE were the most effective in vitro, likely due to the high concentrations of acetic 106 acid, phenols, and isoflavonoids, which disrupt fungal membrane integrity and 107 mitochondrial function. In in vivo assays, the severity of peduncle rot was significantly 108 reduced by the application of BEs, without compromising the fruits' physicochemical 109 quality. Parameters such as total soluble solids (°BRIX) and pH remained stable 110 between treatments. Enzymatic analyses revealed that BEs significantly increased the 111 activity of antioxidant enzymes, including catalase (CAT), peroxidase (POX), 112 polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL). This induction of 113 the host defense system, along with the reduction in hydrogen peroxide (H2O2) levels, 114 suggests that BEs mitigate disease by intensifying ROS detoxification and tissue 115 lignification. The results indicate that BEs, especially RPE and GPE, are highly 116 effective in suppressing diseases caused by Fusarium, maintaining fruit quality. The 117 second study investigated the effect of organic acids on the management of the same 118 fungi, on enzymatic activity, and on melon quality. In the in vitro assay, a completely 119 randomized design (CRD) was used with acetic acid (AA), ascorbic acid (AsA), citric 120 acid (CA), and lactic acid (LA) at concentrations of 0.5%, 1.0%, 1.5%, and 2.0%, 121 controls, negative (potato dextrose agar culture medium), and positive (Graduate A+® 122 fungicide), with four replicates, to determine the percentage of mycelial growth 123 inhibition (PGI) of the fungi. In the in vivo assay, also in a CRD, the treatments 124 consisted of the same acids as in vitro at 1.5%, and the controls: positive (Graduate 125 A+®) and negative (sterile distilled water), with six replicates. Melons cv. Jadeal 126 inoculated with 1 × 106 conidia/mL were used. The severity of rot, post-harvest 127 parameters, and the activities of the enzymes catalase, peroxidase, polyphenol 128 oxidase, phenylalanine ammonia-lyase, and hydrogen peroxide were evaluated. In 129 the in vitro assay, AA and LA were the most effective against F. falciforme. For F. 130 sulawesiense, there was no difference between AA, AsA, CA, and LA. In the in vivo 131 assay, all acids performed similarly to the fungicide against F. falciforme. For 132 F.sulawesiense, AsA and CA were superior to the other treatments. There was no 133 statistical difference between treatments in most of the post-harvest variables 134 evaluated. In enzymatic activities and hydrogen peroxide, AA, AsA, and CA acids 135 stood out. It is concluded that AsA and CA were the most effective acids, promoting 136 the greatest reductions in pathogen growth and disease severity, and contributing to 137 the maintenance of yellow melon quality

MEMBROS DA BANCA:
Interna - 1226708 - ANDREIA MITSA PAIVA NEGREIROS
Externa à Instituição - CYNTHIA CAVALCANTI DE ALBUQUERQUE - UERN
Interna - 2578315 - JAILMA SUERDA SILVA DE LIMA
Presidente - 1544411 - MARCIA MICHELLE DE QUEIROZ AMBROSIO
Externo à Instituição - Washington da Silva