Compostos orgânicos voláteis emitidos por Fusarium oxysporum apresentam atividade nematicida
Year: 2016
Type: dissertation
Abstract: A series of assays was carried out aiming to understand the nematicidal activity \nof the volatile organic compounds (VOCs) emitted by Fusarium oxysporum \nisolated 21 (Fo-21) on plant-parasitic nematodes. Through analysis by gas \nchromatography coupled to mass spectrometry (GC-MS) 50 compounds were \ndetected in the Fo-21 emission. The main classes of compounds emitted by Fo-21 were sesquiterpenes, esters and alcohols. Water exposed to VOCs caused \n100% immobility in second-stage juveniles (J \n2) of Meloidogyne incognita. In \naddition, inoculation of those J2 in tomato decreased infectivity up to 70% and \nreproduction up to 65%. Application of water exposed to VOCs in substrate \ninfested with M. incognita J \n2 resulted in 56% reduction in number of galls and \n49% in number of eggs. The eight most abundant VOCs emitted by F.o–21 were \ntested against M. incognita and Heterodera schachtii. Compounds 2– \nmethylbutyl acetate (1), 3-methylbutyl acetate (2), ethyl acetate (7) and, 2-methylpropyl acetate (8), caused in vitro mortality of 100%, 92.5%, 100% and \n83.8%, respectively, in M. incognita and 90.0%, 88.8%, 96.3% and 97.5% \nmortality, respectively, on H. schachtii J \n2, when tested at a concentration of 500 \nµg.ml \n-1 \n. The lethal concentration (LC50) for compounds 1, 2, 7 and 8, in M. \nincognita J \n2 was of 236, 198, 213 and 218 µg.ml \n-1 \n, respectively. Under the same \nconditions, the commercial nematicide carbofuran (2,3-dihydro-2,2-dimethyl-1-benzofuran-7-yl N-methylcarbamate) showed a LC50 of 191 µg.ml \n-1 \n. Eggs \nexposed to compounds 1, 2, 7 and 8, for 72 h showed a reduction in hatching of \n36.5%, 55.2%, 91.0% and 10.3%, respectively, and reduction in infectivity of \n53.0%, 53.0%, 32.0 % and 39.0%, respectively. When compounds were applied \nin tomato seedlings infested by M. incognita, compound 1 reduced the number \nof galls per gram of root in 27.5% when compared to the negative control \n(without the application of nematicide).
Author: Terra, Willian César
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2592246770