Study On Biocontrol Of Myrothecium Spp.for Grape Anthracnose And Other Diseases

Grapes play an important role in the world.At present,the main grape cultivars in production are Vitis vinifera L.,which has good quality,but is susceptible to various fungal diseases.Grape anthracnose is one of the main diseases that effect the yield and quality of grapes.At present,chemical fungicides are mainly used to control grape anthracnose,but chemical control increases production costs and risks of environment pollution and food safety.In addition,repeated using of fungicides will enhance the drug resistance of pathogenic pathogens.Therefore,it is urgent to develop a green,safe and pollution-free biological control method to effectively control anthracnose.This study focuses the problems of grape production to control anthracnose using three species of Myrothecium.The main results are as follows:1、The three species of Myrothecium displayed significant inhibitory effects on Elsino?ampelina.The inhibitory effect from strong to weak were M.verrucaria,M.roridum,and M.cinctum,respectively.The results of the confrontation experiment showed that the inhibition rate of M.verrucaria,M.roridum and M.cinctum were 54.7%,31.8%,28.3%for E.ampelina,respectively.It was found that M.verrucaria extract can significantly inhibit of the growth of E.ampelina at 5%concentration.M.roridum and M.cinctum extract completely inhibit the mycelial growth of E.ampelina at 10%concentration and 15%concentration,respectively.The conidial germination assay showed that the conidia germination rate was 5%under 5%concentration of M.verrucaria extract,while that of control was 75%.2、The extract of three species of Myrothecium.significantly inhibit the occurrence of grape anthracnose by inhibiting the mycelial growth of E.ampelina,reducing the area of lesion and incidence index.The disease index,conidia germination rate and biomass of E.ampelina were significantly lower than those of the control after treatment with extract of Myrothecium spp..The control effect from strong to weak was M.verrucaria,M.roridum and M.cinctum.It was found that treatment with M.verrucaria extract before inoculation with E.ampelina was better than the treatment after inoculation when compared the control and different treatments.3、M.verrucaria also has a significant control effect on Botrytis cinerea.while no inhibitory effect was observed on Plasmopara viticola and Colletotrichum gloeosporioides.Biocontrol experiments were conducted using leaves and fruits of susceptible‘Thompson Seedless’and‘Red Globe’,the results showed that the disease index,conidia germination rate and biomass of B.cinerea were significantly lower than the control after application with M.verrucaria extract.The incidence index of gray mold was significantly reduced after treatment with M.verrucaria extract on the grape fruit,and the biomass of B.cinerea was significantly lower than that of the control.Treatment with the extract of M.verrucaria before inoculation with B.cinerea was better than treatment after inoculation.The biocontrol of M.verrucaria extract has not significant effect on grape downy mildew when compared with the control.The growth of Colletotrichum gloeosporioides was not completely inhibited at 20%concentration.Those results indicated that P.viticola and C.gloeosporioides were less sensitive to M.verrucaria than E.ampelina.4、The main antifungal substance of M.verrucaria is Verrucarin A.G1 and H1components were obtained with higher antifungal activity.Through extraction,concentration,separation,purification,and antifungal evaluation of the M.verrucaria extract,the antifungal substance was verrucarin A according to ¹H and ¹³C data of nuclear magnetic resonance（NMR）.