ANTIMICROBIAL EFFECT OF CHINESE MEDICINAL PLANT CRUDE EXTRACTS AGAINST RHIZOCTONIA SOLANI AND PYTHIUM APHANIDERMATUM

Medicinal plants have been found to natural anti-fungal and anti-oomycete compounds to defend plants against pathogenic organisms. Here we evaluated in vitro anti-fungal and anti-oomycete effect of the crude methanol extract from 103 Chinese medicinal plant species against Rhizoctonia solani and Pythium aphanidermatum. Twelve crude methanolic extracts showed strong anti-fungal and anti-oomycete activities against both pathogens using the paper disc diffusion method. The highest anti-fungal and anti-oomycete plant extract Glycyrrhiza uralensis that showed significant inhibitory effect against both pathogens and preferred for more assessment. Most effective solvent of methanolic extract from G. uralensis was separated through silica gel plates and each phase was evaluated for anti-fungal and antioomycete activity. The ethyl acetate phase of G. uralensis completely suppressed the radial growth of R. solani and P. aphanidermatum in vitro and in vivo. Taken together, our results indicate that ethyl acetate phase is an important antimicrobial constituent of G. uralensis, and that its anti-fungal and anti-oomycete effect is attributed to the control strategies of these pathogens.