Control Characteristics Of Extracts Of Sunflower Disc And Stalk To Early Blight And Dry Rot Of Potato

Six different kinds of extracts were extracted from crushed sunflower disc and stalk with three different kinds of solvent: water,ethyl acetate and petroleum ether by treatments of leaching,centrifugation,distillation,freeze drying,respectively.The inhibition characteristics of six extracts to pathogenic fungi of dry rot: Fusarium sulphureum and pathogenic fungi of early blight: Alternaria alternate were studied by bacteriostatic test.Inhibition characteristics of extracts which have been verified with ability to inhibit Fusarium sulphureum were tested further for the activities of four cell-wall degrading enzymes: polygalacturonase(PG),polymethyl-galacturonase(PMG),carboxymethyl cellulose(Cx)and ?-glucosidase when F.sulphureum invested three different kinds of potato varieties: Longshu No.7,Longshu No.10 and Xindaping and the control characteristic of potato dry rot,the results showed that:1.The inhibition characteristics of six extracts to Fusarium sulphureum and Alternaria alternate(1)Three extracts of sunflower disc and petroleum ether extract of sunflower stalk had inhibition to F.sulphureum and A.alternate.The inhibiting abilities were increased with the increasing of concentrations and arrived to stabilization at a certain concentration,as same as the inhibition characteristic of ethyl acetate extracts of sunflower stalk to F.sulphureum.The ethyl acetate extract of sunflower stalk had no inhibition to A.alternate.The water extract of sunflower stalk had no inhibition to F.sulphureum and Alternaria alternate.(2)The best concentration to inhibit F.sulphureum of water,ethyl acetate and petroleum ether extracts of sunflower disc were 320mg/mL,160mg/m L,240mg/m L respectively.The best concentration to inhibit A.alternate of water,ethyl acetate and petroleum ether extracts of sunflower disc were 320mg/mL,240mg/m L,160mg/m L respectively.The best concentration to inhibit F.sulphureum of ethyl acetate and petroleum ether extracts of sunflower stalk were 160mg/mL and 240mg/mL.The best concentration to inhibit A.alternate of petroleum ether extract of sunflower stalk was 160mg/m L.2.The inhibition of five extracts to activities of four cell-wall degrading enzymes: polygalacturonase(PG),polymethyl-galacturonase(PMG),carboxymethyl cellulose(Cx)and ?-glucosidase(1)Three extracts of sunflower disc,ethyl acetate and petroleum ether extracts of sunflower stalk had inhibition to activities of four cell-wall degrading enzymes: PG,PMG,Cx and ?-glucosidase when F.sulphureum invested three different kinds of potato varieties: Longshu No.7,Longshu No.10,and Xindaping.(2)The best concentration of water extract from sunflower disc to inhibit activities of four cell-wall degrading enzymes was 320mg/mL.Treated by water extract of sunflower disc at the best concentration,the activities of PG and ?-glucosidase in Longshu No.7 could reduce to uninfected levels,but the activity of ?-glucosidase couldn't reach a significant level.The activities of PMG and Cx in potato tubers of Longshu No.7 and the activities of 4 cell-wall degrading enzymes in potato tubers of Longshu No.10 and Xindaping couldn't reduce to uninfected levels.(3)The best concentration of ethyl acetate extract from sunflower disc inhibiting activities of four cell-wall degrading enzymes was 160mg/m L.Treated by ethyl acetate extract of sunflower disc at the best concentration,four cell-wall degrading enzymes in Xindaping and PG,PMG in Longshu No.7 could reduce to uninfected levels,but the activities of Cx,?-glucosidase in Longshu No.7 and four cell-wall degrading enzymes in Longshu No.10 couldn't reduce to uninfected levels.(4)The best concentration of ethyl acetate extract from sunflower stalk inhibiting activities on four cell-wall degrading enzymes was 160mg/m L.Treated by ethyl acetate extract of sunflower stalk at the best concentration,the activities of PG in Longshu No.7 and PG,Cx,?-glucosidase in Longshu No.10 could reduce to that of uninfected,but the activities of PMG,Cx and ?-glucosidase in Longshu No.7,PMG in Longshu No.10,four cell-wall degrading enzymes in Xindaping couldn't reduce to uninfected levels.(5)The best concentration of petroleum ether extract from sunflower disc inhibiting activities of four cell-wall degrading enzymes was 240mg/m L.Treated by petroleum ether extract of sunflower disc,the activities of PG,PMG in Longshu No.7 can reduce to uninfected levels but the activities of Cx,?-glucosidase in Longshu No.7 and four cell-wall degrading enzymes in Longshu No.10 and Xindaping couldn't reduce to uninfected levels.(6)The best concentration of petroleum ether extract of sunflower stalk inhibiting activities of four cell-wall degrading enzymes was 240mg/m L.Treated by petroleum ether extract of sunflower stalk,four cell-wall degrading enzymes in Longshu No.7,Longshu No.10,and Xindaping couldn't reduce to uninfected levels.(7)Three kinds of sunflower disc extracts had good control effect to potato dry rot in Longshu No.7.Ethyl acetate extract of sunflower disc had good control effect to potato dry rot in Xindaping.Ethyl acetate extract of sunflower stalk had good control effect to potato dry rot in Longshu No.10.