In vitro nematicidal activity of extracts of bulbs and seeds of onion against root-knot nematode Meloidogyne incognita

Abstract

Among the various solvent extracts of the bulbs and seeds of onion assayed far in vitro nematicidal activity against root-knot nematode, Meloidogyne incognita, hot methanol extract of defatted seeds exhibited significant activity. The active extract contained a compound which fluoresced in ultra violet light; it coloured pink when sprayed with diazotized sulphanilic acid followed by sodium hydroxide on a TLC plate. Free amino acids viz. leucine (isoleucine), aspartic acid, methionine and threonine each exhibited nematicidal activity, but to a much lesser extent than the extract itself.