title: Allelopathy of yellow fieldcress (Rorippa sylvestris): Identification and characterization of phytotoxic constituents.
abstract: Both the neutral and acidic fractions of the acetone extract of yellow fieldcress (Kireha-inugarashi,Rorippa sylvestris Besser) inhibited lettuce seed germination. Salicylic,p-hydroxybenzoic, vanillic, and syringic acid were identified in the acidic fraction. In the neutral fraction, hirsutin (8-methylsulfinyloctyl isothiocyanate), 4-methoxyindole-3-acetonitrile, and pyrocatechol were identified. Bioassay using a root exudate recirculating system showedR. sylvestris during flowering inhibited the lettuce seedling growth. Hirsutin (13μg/plant/day) and pyrocatechol (9.3μg/plant/day) were the major compounds released into the rhizosphere. Several combinations of pyrocatechol,p-hydroxybenzoic acid, vanillic acid, and hirsutin reduced lettuce seedling growth. These compounds seemed to be allelochemicals.
authors.affiliation: Department of Agricultural Chemistry, Faculty of Agriculture, Hokkaido University, 060, Sapporo, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Yamane
authors.forename: H
authors.initials: H
authors.lastname: Nishimura
authors.forename: J
authors.initials: J
authors.lastname: Mizutani