Antifungal activity of plant extracts against Embellisia astragali, the fungal causal agent of yellow dwarf and root-rot disease of standing milkvetch

Abstract

In an attempt to find biological fungicides, we screened 18 medicinal plants used in Chinese traditional medicine for their activity against Embellisia astragali, the causative fungus of yellow dwarf and root-rot disease in standing milkvetch (Astragalus adsurgens Pall.). The antifungal efficacy of ethanolic extracts of these plants was tested in vitro. Our results show that among the 18 plants tested, the ethanolic extracts of Saposhnikovia divaricata, Allium sativum and Juglans regia totally inhibited mycelial growth of E. astragali. These three extracts also significantly inhibited spore germination of E. astragali, with inhibition rates ranging from 86% to 88%. In addition, the same extract from the same plant part indicated the strongest antifungal activity against E. astragali, with a minimal inhibitory concentration value of 50 mg mL–1. These results demonstrate that plant-derived products have a high potential to control yellow dwarf and root-rot disease in standing milkvetch.