Primary study on fungistasis and fungistatic mechanisms of Xanthium sibiricum on Botrytis cinerea

The mode of action of an acetone extract from Xanthium sibiricum on Botrytis cinerea,including the inhibition effect on hyphae,spore formation and germination of B.cinerea spores were studied.We also tested penetrability of cell membranes and change of soluble protein content and CAT following treatment with the extraction of X.sibiricum,and the shape of hyphae was observed.The extract from X.sibiricum had high antifungal activity to B.cinerea.When the concentration was 20 mg/mL,the inhibition rate was over 70%.The EC50 was 11.74 mg/mL.Following treatment with 30 mg/mL of extract from X.sibiricum,quantity of conidiophores of B.cinerea were 33 500.Compared with the CK of 225 000,the inhibition rate was 85.1% and that of spore germination reached 77.4%.The X.sibiricum extraction had a strong inhibition effect on the formation and germination of spores of B.cinerea.It resulted in leakage from mycelium and change of cell membrane permeability to increased conductivity.Soluble protein content and CAT from B.cinerea also declined.The extracts caused conidial germ tubes to become shorter and weaker and hyphae were not generally uniform in shape,had more branching and a longer space between burls.Conidiophores were malformed.