Inhibitory Effects Of Lycorine And Berberine On Plant Pathogenic Fungi And Respective Physiological Inhibition Indexes Analysis

China is a big agricultural country and suffers huge loss on agricultural productiondue to different infectious pathogens diseases every year. According to statistics,about70%of these diseases were caused by fungi. A large number of chemicalpesticides were used to control fungal diseases for a long time and got certaineconomic benefits in a short time. However, many problems caused by chemicalpesticides seriously impact on people’s health and the ecological balance. Hence,searching for new, effective, environmentally friendly fungal disease prevention andtreatment methods becomes an urgent task. The biological fungicide is a kind ofpesticide originated from natural compounds, directly or indirectly produced bybiological or living organisms. Biological fungicides have a lot of advantages, such aswide range of sources of raw materials, the safety of non-target organisms, lowtoxicity, and good environmental compatibility. Currently, biological fungicidesbecome a new trend of the global fungicides R&D.In this study, we measured mycelial growth rates of two alkaloids (berberine andlycorine) anti-fungal spectrum and virulence activity to evaluate their activities,respectively. The mycelia growth was observed by optical microscope to understandthe anti-fungal mechanism, which explores the feasibility of alkaloids biologicalfungicides.For inhibitory test of two alkaloids against pathogenic fungi, lycorine hadbroad-spectrum and significantly anti-fungal effects; In addition, certain concentration of berberine also had a broad-spectrum activities against various plant pathogenicfungi.According to the anti-fungal spectra measurement results of berberine and lycorine,we selected the pathogenic fungi with more than50%inhibiting rate to determine thevirulence role. With the increasing concentration of lycorine and berberine, theinhibitory effects of drug on the plant pathogenic fungi were gradually increased.Optical microscope (OM) observation experiment was conducted in order to probethe anti-fungal mechanism of lycorine. Mycelial growth was inhibited significantlyand mycelia number, branch and separated were decreased significantly and thenormal growth of mycelia was obviously affected. The study on pathogenic fungalcell membrane permeability, soluble protein content, succinate dehydrogenase,absorption of nutrients have got an in-depth understanding of the anti-fungalmechanism of alkaloids.