Production d'une substance rhizogène à effet similaire à celui de l'acide indole acétique par le ver de terreLumbricus terrestris

Abstract

In vitro biological tests show that excreta or gross total and partial extracts of Lumbricus terrestris stimulate rhizogenesis and enhance root growth in young plants of the bean Phaseolus vulgaris. Similar results were obtained in experiments with worms freshly collected in the field and with worms previously deprived of food for 4 weeks. The rhizogenous substance produced by the worms is therefore not of exogenous origin, coming from the soil via the digestive tract. The similar effects of indol acetic acid at different concentrations and of excreta and gross extracts of worms in various dilutions indicate that the rhizogenous substance is similar to indol acetic acid, a well-known phytohormone in plants. Expressed as indol acetic acid equivalents, the quantity of the rhizogenous substance in worms would be approximately 18 × 103ng/g, of which half (9 × 103ng/g) is released in the excreta alone.[Journal translation]