Studies on Medicago lupulina saponins. 4. Variation in the saponin content of M. lupulina

Abstract

The saponin content in the tops of black medic trefoil cv. Renata as well as in some botanical and breeding lines of M. lupulina was analysed. It was found that the concentration of biologically active (hemolytically active) saponins in the tops of M. lupulina cv. Renata was 2.5% of dry matter. Total saponin content was 3.5% of dry matter. Among 500 individually analysed plants of the Renata variety, the saponin contents ranged from 0.07 to 0.5% in the leaf sap. No saponin-free plant was found. The saponin content was additionally analysed in 300 breeding and 11 botanical lines of M. lupulina. Great differences in that material were found but no saponin-free line was present. The saponin content in the particular plant parts as well as in the whole tops of M. lupulina throughout the vegetation season was also measured. The possibility and necessity of the selection for a low saponin population of M. lupulina is discussed.