Effects of triterpenoid saponins of field scabious (Knautia arvensis L. Coult.), alfalfa, red clover and common soapwort on growth of Gaeumannomyces graminis var. tritici and Fusarium culmorum

摘要

Field scabious (Knautia arvensis L. Coult) was chosen for study, as it was previously identified among 500 plants as potential anti-proteolytic feed additive for ruminants and reducing the number of protozoa, due to its saponin content. Saponins fromaerial parts of field scabious, alfalfa and red clover as well as roots of common soapwort were tested in agar medium to study their effects on growth of two major pathogens of cereals: Gaeumannomyces graminis var. tritici (Ggt) and Fusarium culmorum (Fc). All saponins inhibited the Ggt growth. Most active saponins were from soapwort (IC5o 14.1 ug/ml) followed by alfalfa (IC5o 148.5 ug/ml) and red clover (IC50 156.8 ug/ml), whereas field scabious were almost inactive (IC50 >1000 ug/ml). Saponins from alfalfa, red clover and field scabious stimulated the Fc growth and only the compounds from common soapwort were slightly inhibitory to Fc growth. In most cases, the effects of saponins on growth of both fungi was dose-dependent.