Banca de QUALIFICAÇÃO: TATIANNE RAIANNE COSTA ALVES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : TATIANNE RAIANNE COSTA ALVES
DATA : 25/06/2025
HORA: 14:00
LOCAL: Sala 21 PROPPG
TÍTULO:

1: MELON CULTIVATED IN CONTINUOUS MONOCULTURE REGIMES CAUSES CHANGES IN SOIL COMPOSITION AND MICROBIAL ACTIVITIES

2: POTENTIAL OF COMBINED USE OF BACTERIA AND METABOLITES, IN REDUCTION OF ROOT ROT IN MELON AND INCREASING SOIL ENZYMATIC ACTIVITY

PALAVRAS-CHAVES:

1:  Soil health, Microbiome, Organic matter;

2: Soil-borne pathogens; Biological control; Plant disease; Cucurbitaceae.

PÁGINAS: 47
RESUMO:

1: The present study evaluated microbial activity and diversity in clay and sandy soil types subjected to different periods of successive melon monoculture. Soil samples were collected from three farms in the semiarid region of Northeastern Brazil with 8, 15, and 20 years of melon monoculture. Soil samples were also collected from native areas. To evaluate the biological quality of the soil, the enzymes arylsulfatase, β-glucosidase, and acid phosphatase, total organic carbon, labile carbon, microbial biomass carbon, quantification of total and, sporulating bacteria, and fungi were evaluated. The soil microbiome was also analyzed. The native area showed greater activity of the analyzed enzymes, for both soil textures. In clay soils, there was a reduction in the performance of these enzymes as the years of monoculture increased, with a reduction in β-glucosidase activity of more than 70% compared to native soils. The carbon input of the areas showed a similar behavior, with a decrease of 63.8% in the area with 20 years of cultivation compared to the control. Soil bacterial diversity was significantly lower in melon monoculture sites compared to native soils, as measured by 16S rRNA gene sequencing. Additionally, specific bacterial taxa exhibited altered relative abundances in response to monoculture conditions, with common taxa showing similar shifts across both soil types. Collectively, these data suggest that melon monoculture causes a reduction in carbon content, enzymatic activity, and microbial diversity in cultivated soils over time. 

2: The present study aims to assess the effect of formulations based on bacteria, Trichoderma, and metabolites in the management of soil-borne pathogens of melon plants. A pilot greenhouse study was conducted, and the treatments that provided the lowest disease severity underthose conditions were tested in the field. The experiment was carried out in areas with a history of diseases caused by soil-borne pathogens, with a randomized block experimental design, with six treatments and seven replicates:T1 = (Bacillus subtilis and B. licheniformis + Metabolites 1), T2 = (B. subtilis, Lactobacillus plantarum and Enterococcus faecium + Metabolites 2), T3 = (Metabolites 1 + metabolites 2), T4 = (B. subtilis, B. licheniformis + L. plantarum and E. faecium + Metabolites 1 + Metabolites 2), T5 = standard management (T. asperelum, B. subtilis, metabolites 1 and metabolites 2), and T6 = Control. The following parameters were evaluated: plant stem diameter, shoot dry mass, disease severity, number of fruits per plant, fruit’s weight and ºbrix, and soil enzymes. Treatments 2 and 3 of the first experiment, and treatments 1 and 4 of the second experiment demonstrated better performance in reducing disease severity, with reductions of 50% compared to the control. For this parameter, none of the treatments showed great prominence; however, treatment 4 showed promising signs, such as greater activity of soil enzymes, a greater number of fruits per plant, and was one of those that provided the greatest reduction in the severity of the disease caused by soil-borne pathogens in melon.

MEMBROS DA BANCA:
Externa à Instituição - CYNTHIA CAVALCANTI DE ALBUQUERQUE - UERN
Interna - ***.511.964-** - EDICLEIDE MACEDO DA SILVA - UFERSA
Presidente - 1544411 - MARCIA MICHELLE DE QUEIROZ AMBROSIO
Interno - 1445570 - RUI SALES JUNIOR
Interno - ***.076.546-** - WASHINGTON LUÍS DA SILVA - CAES