Banca de DEFESA: FRANCISCO JOSÉ CARVALHO MOREIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : FRANCISCO JOSÉ CARVALHO MOREIRA
DATA : 30/11/2018
HORA: 14:00
LOCAL: Sala SS1 do DBG do Centro de Biociências - UFRN
TÍTULO:

Prospecting extracts of Tephrosia toxicaria Pers. for control of root-knot nematodes and development of bionanformulations derived from extracts for application as nematicides in agriculture.

PALAVRAS-CHAVES:

Timbó; Meloidogyne; bioactive molecules; nanoencapsulation; ecotoxicity; cytotoxicity.

PÁGINAS: 170
GRANDE ÁREA: Ciências Biológicas
ÁREA: Biologia Geral
RESUMO:

Among the phytonematoids, the genus Meloidogyne stands out, due to its genetic plasticity, versatility and adaptability, which places them as the main group causing damage to agriculture. Several compounds of plant origin have nematicidal activity, are profitable and environmentally safe, and can be used in organic farming systems, however, many of these products degrade easily, reducing persistence, making control difficult. In this sense, the nanoencapsulation of botanical pesticides presents as a formidable technology, being able to transform the physical state of the substances for better manipulation, allowing the optimization of formulations with controlled release, thus avoiding their degradation, due to adverse conditions. The objective of this work was to evaluate the in vivo nematicidal activity of the aqueous and hydroalcoholic extracts of stems, leaves and roots of Tephrosia toxicaria in the control of root-knot nematodes (Meloidogyne enterolobii and M. javanica) in 'Pati' tomato their environmental evaluation through cytotoxicity in 3T3 cells and soil ecotoxicity in Caenorhabditis elegans. Then another set of assays to evaluate the in vitro effect of the aqueous and hydroalcoholic extracts free and conveyed in SNEDDS colloidal system of the roots of T. toxicaria on root-knot nematodes (M. enterolobii and M. javanica) and their environmental evaluation, with aquatic ecotoxicity in microcrustaceans (Ceriodaphinia dubia) and phytotoxicity in lettuce (Lactuca sativa). The results demonstrate that aqueous extracts of leaves, stems and roots of T. toxicaria were efficient in the control of M. enterolobii and M. javanica, and the leaves and roots were more promising, from the concentration of 0.8 %, revealing the potential of these for the development of alternatives for the control of gnats nematodes with low cost and low environmental risk. As for the second assay, it was observed for the free aqueous extract, inhibited hatching and caused mortality (100%) of the J2 from 0.2%; while free hydroalcoholic extract inhibited hatching from 0.1% and total mortality from 0.2%, with similar behavior for both nematodes. As the hydroalcoholic extract, which gave greater inhibition of hatching and mortality of juveniles. With the introduction of the extracts in colloidal SNEDDS (Self-nanoemulsifying drug delivery systems) containing aqueous and hydroalcoholic extracts of roots of T. toxicaria were effective, in vitro, in the inhibition of hatching and on the mortality of J2, inhibition complete of hatching from 0.10 and 0.025%, respectively; and total mortality from 0.050% in the two types of extracts conveyed; it was also verified that the free extracts caused mortality in only the two highest concentrations (1.6 and 3.2%), whereas the extracts showed no aquatic toxicity to the microcrustacean (C. dubia); as for phytotoxicide on germination of lettuce (L. sativa) seeds 'Summer Nanny' there was no harmful effect. Considering these results, we can conclude that the polar extracts of T. toxicaria present potential for application as a botanical nematicide. The SNEDDS system presented efficiency as a carrier system of the biomolecules of aqueous and hydroalcoholic extracts of T. toxicaria, maintaining the nematicidal effect of the active principles, demonstrating potential as a new input for the management of gall nematodes. The data set indicate the extracts of T. toxicaria as an alternative to the control of gall nematodes, with significant effect at low concentrations and with reasonable environmental safety. The SNEDDS, system carrier of the polar extracts demonstrated potential as a new input for the management of gall nematodes, which resulted in a patent deposit with the National Institute of Industrial Property (INPI), therefore, a formulation that could be used commercially in the agriculture.

MEMBROS DA BANCA:
Presidente - 1549705 - ADRIANA FERREIRA UCHOA
Interno - 1880243 - DANIEL CARLOS FERREIRA LANZA
Interno - 347401 - GORETE RIBEIRO DE MACEDO
Externo à Instituição - LEONARDO LIMA PEPINO DE MACEDO - EMBRAPA
Externo à Instituição - LUDOVICO MIGLIOLO - UCB
Interno - 373.201.654-49 - MARIA APARECIDA MEDEIROS MACIEL - UnP