Banca de DEFESA: LUIZIENE SOARES ALVES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : LUIZIENE SOARES ALVES
DATA : 24/01/2019
HORA: 09:00
LOCAL: Programa de Pós-graduação em Química - IQ
TÍTULO:

Grain productivity, content and quality of the seed oil, and biological potential of leaf and capitulum extracts of sunflower grown under differential boron supply.

PALAVRAS-CHAVES:

Helianthus annuus L., antioxidant capacity, allelophatic potential.

PÁGINAS: 120
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
RESUMO:

Sunflower is highlighted in the food industry as a result of its high grain productivity and oil quality. Its properties have been generating special interest on chemical research because of secondary metabolites with biological potential. A limiting factor to be considered for sunflower characteristics is nutrient availability. Among essential micronutrients, sunflower’s culture has high sensibility to excessive input of Boron element (B). This element acts on physiological and morphological processes and, therefore, it affects chemical and agronomic aspects. This work aims to evaluate sunflower’s grain productivity, content and quality of the seed oil. Moreover, the biological potential of sunflower’s tissue extracts grown under differential boron supply. During field experiments, three sunflower’s genotypes (Helio251, BRS323 and BRS324) were supplied with different doses of B: 0, 2.5, 5 and 8 kg ha^-1. The B sensibility was evaluated using the amount of grains, content and quality of the seed oil, and B content in grains. The biological potential was determined using the highest B-sensitive genotype (Helio251). Aqueous (0.1 and 0.5%) and ethanolic (0.025 and 0.050%) extracts were produced using leaf and capitulum tissues, which were collected during R5 field stage. Afterwards, “in vitro” and “in vivo”assays led us to estimate antioxidant capacity and activity, respectively. Furthermore, aqueous extracts of leaf and capitulum (2.5, 5 and 10%) were evaluated in relation to its allelophatic potential on seed germination of Digitaria insularis. As a result, genotypes shown distinct response for B fertilization on field experiment. This micronutrient influenced grain productivity of the Helio251 and BRS323, and oil content in all genotypes. However, B was not recognized on major unsatured fatty acid profiles and grain protein. Despite of that, it was observed genotypical differences in oil quality, either on fatty acid parameters or on crude protein content. In vitro evaluation of hydroalcoholic and aqueous extracts of leaves and capitulum confirmed phenolic content, absence of flavonoids and antioxidant capacity, with ABTS and FRAP methods. As to the Saccharomyces Cerevisiae biological model shown antioxidant activity in aqueous and ethanolic extracts using “in vivo” assays. However, better values for antioxidant activity were found using ethanol as extraction solvent. Through analysis of HPLC, it was confirmed chlorogenic antioxidant compounds. This work allowed us to observe multiple functions of B, and its biological potential in sunflower leaves and capitulum extracts. It was noticed that B element influences sunflower crop production either negatively or positively, depending on the applied dose and genotype. In summary, the amount of antioxidant components changes with B supply. Moreover, sunflower has secondary metabolites with allelopathic and antioxidant contents that have potential to be useful for both chemical and agricultural industries.

MEMBROS DA BANCA:
Interno - 1844240 - CRISTIANO JORGE RIGER
Interno - 1177598 - ROSANE NORA CASTRO
Externo ao Programa - 1809123 - ANDRE MARQUES DOS SANTOS
Externo ao Programa - 750.960.133-91 - EDNALDO DA SILVA ARAÚJO - EMBRAPA
Externo à Instituição - CARLOS VERGARA TORRES JÚNIOR
Externo à Instituição - MANLIO SILVESTRE FERNANDES