Banca de DEFESA: JAIR LUCAS OLIVEIRA JUNIOR

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JAIR LUCAS OLIVEIRA JUNIOR
DATA : 16/06/2021
HORA: 09:00
LOCAL: sala da plataforma Conferência Web RNP (https://conferenciaweb.rnp.br/webconf/ppgbiotec-ufba)
TÍTULO:

Biochemical and physiological profiles of Brazilian pepper tree (Schinus terebinthifolius Raddi) seeds under storage and germination under water restriction conditions

PALAVRAS-CHAVES:

Anacardiaceae; Brazilian pepper, Seed quality; Water restriction; Antioxidant enzymes

PÁGINAS: 60
GRANDE ÁREA: Outra
ÁREA: Multidisciplinar
RESUMO:

Brazilian red pepper tree (Schinus terebinthifolius) has been studied mainly for its condiment and medicinal properties, in addition to its importance in the recovery of degraded areas and the restoration of native vegetation. Therefore, due to the importance of obtaining good quality seeds of this species for use in reforestation and commercial planting programs, the objective of this study was to evaluate the biochemical and physiological profiles of seed maturation, storage and germination under conditions of water restriction and after osmopriming. It was observed that the seeds obtained from fruits in the Red stage showed better physiological quality and that the newly harvested seeds showed better germinative performance compared to those that underwent drying. The seeds stored in a refrigerated environment (5ºC) were able to maintain their physiological quality for 15 months, different from those stored at room temperature (24ºC), which remained viable, however, reduced germination and vigor. The changes in the activities of the enzymes superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) in these storage conditions indicate that the enzymatic antioxidant system is related to the maintenance of the viability of the seeds, however, they were not able to prevent the loss of quality, the increase in lipid peroxidation, verified through the quantification of malondialdehyde (MDA), and the permeability of membranes, through the electrical conductivity (EC) test, when stored at room temperature. In water restriction tests, it was observed that the species is highly susceptible to this abiotic stress in the process of germination and initial seedling establishment. Biochemical evaluations showed that the activities of the enzymes SOD, CAT and APX during controlled imbibition increased when subjected to low levels of stress (-0.2 MPa), however, they were reduced in severe levels of water restriction (-0.8 MPa). In seedlings, the first oxidative damage occurred in the roots, confirmed by the reduction of the activity of SOD, CAT and APX by -0.2 MPa. In addition, when using controlled imbibition for osmoconditioning or priming, it was observed that the use of potentials less than -0.2 MPa for 168 h did not promote improvement in the germination and vigor of the seeds of S. terebinthifolius, however, potentials of -0.2 and -0.4 MPa, were able to promote a faster and more uniform germination, indicating that the use of this pre-germinative treatment can contribute to improve the physiological potential of seeds of this species.

MEMBROS DA BANCA:
Externo(a) à Instituição - CIMILLE GABRIELLE CARDOSO ANTUNES
Externo(a) à Instituição - RENATA SILVA-MANN
Presidente - 2085555 - RENATO DELMONDEZ DE CASTRO