Submitted to: International Plant Protection Congress
Publication Type: Abstract Only
Publication Acceptance Date: April 9, 2003
Publication Date: May 11, 2004
Citation: Chitwood, D.J., Meyer, S.L., Nitao, J.K. Isolation and identification of nematode-antagonistic compounds from fungi. Proc. of the 15th International Plant Protection Congress. P. 409. 2004. Technical Abstract: Compounds secreted by biocontrol fungi can provide useful leads for the development of biologically based nematode management tools. Therefore, a bioassay-driven isolation scheme was used to fractionate compounds secreted by two species of fungi originally isolated from Heterodera glycines. Fusarium equiseti and Chaetomium globosum were the fungi selected because their culture filtrates displayed strong activity against H. glycines and Meloidogyne incognita juveniles in a hatching and mobility bioassay. For fractionation of culture broth filtrates, the M. incognita system was used because of greater hatching percentages. The filtrates were crudely purified by passage through Amberlite XAD-16 resin and solvent partition of the methanolic eluate of the resin. Nematode-antagonistic compounds from F. equiseti were purified via column chromatography on silica, reversed phase high performance liquid chromatography, and recrystallization. The active compounds from C. globosum were purified by liquid chromatography on Toyopearl HW-40 resin. Nuclear magnetic resonance spectroscopy and X-ray crystallography indicated that two active compounds from F. equiseti were the trichothecenes 4,15-diacetylnivalenol and diacetoxyscirpenol; flavipin, a dialdehydic phenolic, was similarly identified as the compound responsible for most of the activity in the C. globosum culture filtrate.