Study On The Activities And Mechanism Of Amanita Virgineoides Bas Against Phytopathogenic Fungi

ABSTRACT:The inhibition tests of extracts from the fruiting bodies of Amanita virgineoides Bas shown that the Compound A was effective component among the others ones and the inhibition was evaluated compared to the common fungicides, carbendazim aginst 38 phytopathogenic fungi.The mechanism of inhibition was analyzed,which contributed to the basis of the potential biocides developed from Amanita virgineoides Bas.Involved by the 38 phytopathogenic fungi,the mycelia growth rate tests of the Compound A were demonstrated effective on the Compound A at the concentration of 100μg/mL.All the values of inhibition rates were ranged from 0% to 100%,the inhibition rates of 18 of the all cultures phytopathogenic fungus were more than 50%;and the inhibition rates of 26 phytopathogenic fungi were ranged from 15.7%to 86.3%,more than carbendazim,example Fusarium oxysporum Schl.f.sp vasinfectum,Corynespora cassiicola, Fusarium graminearum Schw, Fusarium graminearum and Corynespora cassiicola(Berk.Curst)Wei;the inhibition rates of 4 phytopathogenic fungi were ranged from 0%to 100%,close to carbendazim,example Aspergillus niger, Fusarium pointed watermelon,Colletotrichum gloeosporioides Penz.et Sacc,Sclerotinia sclerotiorum;the inhibition rates of 8 phytopathogenic fungi were ranged from 8.3%to 66.8%,less than carbendazim,example Colletotrichum gloeosporioides (Penz) Sacc, Fusarium oxysporum f.sp vasinfectum,Trichoderma atrovoride,Pleospora lycopersici Ell.et Liu. Phytopathogenic fungi by the 14 phytopathogenic fungi,EC50 were ranged from 7.76 μ g/mL to 72.73μg/mL,EC5o to Fusarium graminearum was 7.76μg/mL.Thus,L-cyclopropylalanine was regarded as an effective component more than carbendazim.In summary,Fusarium graminearum was observed and studied at tests of inhibitive mechanism. When they were inoculated on the Compound A amended medium at concentration of 7.76μg/mL,The results showed that(1)the mycelia of F. graminearum was short and few.(2)the cell membrance was damaged,substances within the cell had been extravasated, conductivity of extravasation had been increased.(3) chitinase activity of mycelia was elevated.(4)mycelia hadn’t absorbed nutrient.(5)the SDH activities had decreased by 1.18 times after Compound A permeated into the cell.These can be explained as the oxidation-reduction system of mycelia were unbalanced,and the biosythesis of mycelia proteins were affected furtherly even to be destroyed.Compound A could provide theoretical basis for development of new biocides, because it had strong antifungal activity and its possible mechanism of inhibition.There were great practical significance.