Abstract

In the present investigation, antagonistic effect of culture filtrates of Gymnoascus reesii at different concentrations were tested on eggs and juveniles of root knot nematode (Meloidogyne incoginta), invitro. The percentage mortality and inhibition of hatching of root-knot nematode were directly proportional to the concentration of culture filtrates of G. reesii. Compared with the nematicides treatments of Cadusafos and Avermectins, the effects of higher concentration of culture filtrates of G. reesii were in some cases not statistically different. To our knowledge, this is the first report of culture filtrates of G. reesii observed to have nematicidal activity toward root-knot nematode and a  nematicidal metabolite (3E,5E)-2,5-dihydroxy-2,7-dihydrooxepine-3-carboxylic anhydride was isolated based on bioassay-guided fractionation from the extracts of the fungus G. reessii.

Key words: Gymnoascus reesii, nematicidal activity, Meloidogyne incoginta.