Banca de DEFESA: TATIANA DE OLIVEIRA PINTO
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.DISCENTE : TATIANA DE OLIVEIRA PINTO
DATA : 20/02/2020
HORA: 09:00
LOCAL: Programa de Pós-graduação em Fitotecnia
TÍTULO:
Cytogenetic, reproductive, molecular and chemical studies as an auxiliary basis in the genetic improvement of Lippia alba, citral chemotype
PALAVRAS-CHAVES:
Cell division; Meiosis; Plant reproduction; DNA markers; Secondary metabolites; Chromatography; Mass spectrometry; Essential oils.
PÁGINAS: 110
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
SUBÁREA: Fitotecnia
ESPECIALIDADE: Melhoramento Vegetal
RESUMO:
Lippia alba has great medicinal potential. However, selected genotypes are necessary, as there is a great chemical variation in their essential oil. Therefore, knowing its reproductive stability and how it reproduces in the species are important. Modern technologies that contribute to the selection of plants for oil quality must also be implemented. Therefore, this research aimed to analyze, in genotypes of Lippia alba citral chemotype, the meiotic behavior during the formation of pollen grains, investigate evidence of self-fertilization and barriers to its occurrence and verify the possibilities of applying ISSR DNA markers in the selection of citral genotypes for chemical quality of essential oil. To this end, different genotypes of Lippia alba, citral chemotype were analyzed from the germplasm collection of the Plant Production Department/IA at UFRRJ. In the first chapter, flower buds were collected and fixed in acetic acid and 70% ethanol until use. Anthers of the buds were removed and digested with pectinase / cellulase. The meiotic cells were stained with acetic carmine, and the pollen grains with Alexander Solution. All slides were observed under an optical microscope. The phases of meiosis, the number of chromosomes, the level of ploidy were analyzed and the meiotic index (IME) and pollen viability (VIA) were estimated. The genotypic determination coefficient and other important genetic parameters were also estimated from the IME and VIA. The second chapter involved the collection of paraformaldehyde flower buds. These were collected after natural and artificial self-fertilization, and after cross-pollination. The buds were softened with NaOH and stained with aniline blue. The slides were observed under a fluorescence microscope. The presence / absence of pollen tubes was observed in the stigma, style and ovarian cavity of the buds. The third chapter consisted of the analysis of 28 genotypes in the collection, from Minas Gerais and Rio de Janeiro. These had their oil extracted via hydrodistillation (Clevenger) from dry leaves. Then, the oils were analyzed in CG-EM. Genotypes also had their DNA extracted and analyzed via DNA markers of the ISSR type. Chemical and molecular diversity were estimated using the UPGMA cluster. Then, the dendrograms were correlated to obtain the strangulation coefficient (COE), whose objective was to verify how much the ISSR markers contribute in the selection of plants for essential oil quality. The meiosis results without changes. The species is diploid with 2n = 2x = 30 chromosomes. IM (94.38%) and VIA (94.32%) had greater genetic control (H2 = 91.50 and 76.77%, respectively). The species did not present systems of genetic self-incompatibility, since pollen tubes were detected in the stigma, style and ovarian cavity of the genotypes. It is concluded that Lippia alba can be self crossing. Physical barriers to self-fertilization were found. Regarding chemical and molecular analysis, the genotypes were grouped according to the chemical profile of essential oils. COE was estimated at 0.24, indicating high chemical and molecular correspondence. It was possible to apply ISSR markers for plant selection for essential oil quality in Lippia alba.
MEMBROS DA BANCA:
Presidente - 1712769 - PEDRO CORREA DAMASCENO JUNIOR
Externa ao Programa - 2271445 - BRUNA RAFAELA DA SILVA MENEZES
Externa ao Programa - 2147409 - MARILENE HILMA DOS SANTOS
Externa à Instituição - MARCIA SOARES VIDAL - EMBRAPA
Externo à Instituição - ROBERTO DOS SANTOS TRINDADE - EMBRAPA