Differential antifungal activity of alfalfa (Medicago santva L.) saponins originated from roots and aerial parts for some ornamental plant pathogens

Abstract

The total saponins isolated from aerial parts and roots of alfalfa (Medicago sativa L.) at the concentration of 0,01%, 0,05% and 0,1% showed differential influence on the mycelium growth of Alternaria zinniae, Botrytis cinerea, Botrytis tulipae, Phoma narcissi, Phoma poolensis and Rhizoctonia solani. A higher inhibitory effect on in vitro growth of mycelium of all tested pathogens indicated saponins from roots of alfalfa than from aerial parts. Tested saponins from roots at lhe concentration of 0,1% totally inhibited linear growth of Phoma narcissi, and linear growth of Alternaria zinniae was limited about 67%, Botrytis cinerea about 74%, Botrytis tulipae about 68%, Phoma poolensis about 38%, and Rhizoctonia solani about 74% in comparison to the control. The saponins of alfalfa from roots at the concentration of 0,1% and 0,2% applied as preinoculation sprays evidently inhibited the development of Phoma narcissi on Hippeastrum leaves. This dose of aerial saponins of alfalfa did not effect the development of necrotic spots on the leaves.