Avaliação alelopática, mutagênica e fitoquímica de extratos vegetais de três espécies exóticas invasoras
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Data
2017-02-17
Autores
Moreira, Schírley Aparecida Costalonga
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Universidade Federal do Espírito Santo
Resumo
Biological contamination is one of the most serious environmental problems nowadays and contributes to the extinction of native species. Studies aimed at understanding the mechanisms of invasion used by alien species are very important in the search for effective solutions to combat these species allelopathy is a promising field of investigation; however, the relationships between allelopathic effects and intracellular changes are rarely established. This study aimed to analyze the phytochemistry of the foliar ethanolic extract of Acacia mangium Willd (forest mangrove), Artocarpus heterophyllus Lam (jackfruit) and Eriobotrya japonica (Thunb.) Lindl (loquat) as well as infer about their allelopathic actions through four test organisms (Lactuca sativa, Allium cepa, Leucaena leucocephala e Urochloa brizantha) and its mutagenic potential using the A. cepa system. In allelopathic assay, seeds of test organisms germinated on Petri dishes covered with filter paper soaked with deionized water (negative control) or four concentration of each extract (1, 5, 10 and 50 mg/mL); were measured the germination index (GI), germination speed index (GSI), allelopathic index (AI), radicles growth speed index (RGSI), germination mean time (GMT), germination mean speed (GMS) and radicles mean length (RML). For mutagenic assay A. cepa seeds were submitted to continuous and discontinuous (acute and chronic) treatments in medium with deionized water, the herbicide trifluralin (1,9 µL/mL) - positive control -or one concentration of extracts and were measured the mitotic index (MI), aneugenic effect index (AEI), clastogenic effect index (CEI) and anomaly index (AI). A. mangium Willd extract presented in its composition saponins, triterpenes and tanins and affected the GI, GSI and AI of L. sativa, A. cepa and U. brizantha; in relation to GMT, L. leucocephala was the only specie affected. The GMS changed only in L. sativa. All species had RML and RGSI modified. The extract shown cytotoxic properties, since it reduced the MI of A. cepa without changed the AEI, AI and CEI. To A. heterophyllus Lam extract, was detected flavonoids, triterpenes and tanins and occurred significant changes in AI and GI to L. sativa, A. cepa e U. brizantha; the GSI was affected in L. sativa e U. brizantha, while GMT reduced in L. leucocephala e U. brizantha. RML and RGSI of all test organisms were altered. Besides reducing the MI, the extract caused an increase in CEI demonstrating that the observed allelopathic effects are reflections of both a cytotoxic and a genotoxic action. In turn, Eriobotrya japonica (Thunb.) Lindl extract shown flavonoids, steroids, saponins and alkaloids in its phytochemical profile and reduced the GI, GSI and AI in L. sativa, A. cepa and U. brizantha. There was a decline in GMS of L. sativa. The extract of Eriobotrya japonica (Thunb.) Lindl presented cytotoxic and mutagenic potentials and affected RML and RGSI of all test organisms. Of the three species tested, Eriobotrya japonica presented potential for the development of a Biological control for other alien species.
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Alien species , Alelopatia , Allelopathy , Espécies invasoras , A. cepa assay , Ensaio A. cepa , Mutagenicity , Mutagenicidade
Citação
MOREIRA, Schírley Aparecida Costalonga. Avaliação alelopática, mutagênica e fitoquímica de extratos vegetais de três espécies exóticas invasoras. 2017. 200 f. Tese (Doutorado em Biologia Vegetal) - Universidade Federal do Espírito Santo, Centro de Ciências Humanas e Naturais, Vitória, 2017.