禾谷丝核菌对井冈霉素的抗性风险预测

采用菌丝生长速率法,测定了4个麦区的5个禾谷丝核菌Rhizoctonia cerealis菌株对井冈霉素的抗药性;在含井冈霉素的PDA平板培养基上对禾谷丝核菌进行继代培养,以诱导抗药性菌系;测定了抗性菌系对其他杀菌剂的交互抗性,并比较了抗性和敏感菌系对渗透压的敏感性及药剂处理后两种菌系培养液内还原糖和可溶性蛋白的含量差异。结果表明,田间禾谷丝核菌菌株对井冈霉素分别产生了7.26、7.75、10.46、14.92和23.31倍的抗性。室内继代培养36代,禾谷丝核菌对井冈霉素的抗性达49.24倍,形成了抗井冈霉素菌系。抗井冈霉素菌系对 口 恶 醚唑、福美双、三唑酮、丙环唑、戊唑醇和咯菌腈分别产生了48.58、21.78、17.62、10.95、2.55和1.78倍的交互抗性。抗性菌系在较低和较高渗透压下其生长抑制率均大于敏感菌系,用井冈霉素处理抗性和敏感菌系后,其体内的电解质都严重外渗,且抗性菌系在10 h 内的外渗量明显大于敏感菌系。

Studies on the Resistance Risk Forecast to Validamycin against Rhizoctonia cerealis

Resistance of 5 strains of Rhizoctonia cerealis to validamycin collected from 4 wheat-growing areas was measured by using mycelium growth rate method.A sensitive strain of the fungus wassubcultured on the media containing validamycin to induce the resistance development of the strain of R.cerealis,the cross resistance of the resistant strain to other fungicides was studied.The sensitivity of R-strain and S-strain to osmolarity,also the difference of reducing sugar and soluble protein in culture liquid of R-strain and S-strain after treatment with validamycin,were compared.The results showed thatthe resistance level of 5 strainsL2,L1,TA,TW,and JZ to validamycin was 7.26-,7.75-,10.46-, 14.92-and 23.31-fold,respectively.After 36 subcultured on PDA containing validamycin in laboratory,the resistance level of Rhizoctonia cerealis reached 49.24-fold to validamycin,the R-validamycin strain was gained.The resistance level of resistant strain of R.cerealis to difenoconazole,thiram,tridimefon,propiconazole,tebuconazole,fludioxonil was 48.58-,21.78-,17.62-,10.95-,2.55-and 1.78-fold,respectively.Inhibition rate of R-strain was higher than S-strain in the PDA containing 1% and 4% dextrose.In addition,the results of electrolyte leakage showed that the electrolyte of R-stain andS-strain was seriously exosmosised after treatment with validamycin,and the R-strain could leak moreelectrolyte than the S-strain in 10 h.