Comparative Studies of Saponin of Several Alfalfa Varieties Using Chemical and Biochemical Assays¹

Abstract

Saponin content of alfalfa ( Medicago sativa L.) was affected by variety, stage of growth, and percentage of leaves. Leaves were higher in saponin content than stems and immature growth was higher in saponin content than more mature growth. The ‘Du Puits’ variety was higher in saponin content than ‘Lahontan’ and this difference became greater as the growing season progressed. The varietal difference was reflected in the growth rate of chicks fed alfalfa meal differing in saponin content and in the growth rate of Trichoderma viride Pers. ex Fr. growing on water extracts of the varieties. Both qualitative and quantitative differences in alfalfa saponin are suggested by the Trichoderma bioassay. Saponins extracted from the varieties inhibited the germination of lettuce seed to different degrees. This was attributed to qualitative differences in the saponins from the different varieties. Improvement of the feeding value of alfalfa by breeding for low saponin content is an attractive possibility.