Variations in Antioxidase Activities and MDA Content in Potato Tubers Infected by Fusarium trichothecioides

[Objective] This study was conducted to determine the physiological and biochemical characteristics of potato tubers infected by Fusarium trichothecioides. [Method] The soluble protein content, SOD activity, POD activity and malondialdehyde （MDA） content of the tubers of two potato varieties Atlantic and Keshan 1 infected by F. trichothecioides were measured 0, 3, 6, 9, 12, 24 and 48 h later. [Result] Com- pared with the control uninfected, the contents of soluble protein and MDA in the tu- bers of both potato varieties infected with F. trichothecioides decreased, while the SOD activity increased, indicating that SOD activity had a certain relationship with the resistance of potato to dry rot. The POD activity in Keshan 1 which is resistant to F. trichothecioides was higher than in Atlantic, which is susceptible to F. trichothe- cioides, indicating that POD activity was closely related with potato＇s resistance to Fusarium dry rot. [Conclusion] The physiological and biochemical characteristics of potato tubers infected by F. trichothecioides will provide some references for the early waming and prevention of Fusariurn dry rot.

防治玉米苗枯病室内药剂筛选

为合理使用化学农药有效防治玉米苗枯病,采用毒力测定法对16种杀菌剂进行了室内筛选,结果表明,98%烯唑醇、97%多菌灵、70%多·福WP和80%多·福·福锌WP对玉米苗枯病菌有较好的抑制效果,且持效期长;98%烯唑醇和97%多菌灵的毒性明显高于70%多·福WP和80%多·福·福锌WP;安全性测定结果表明,98%烯唑醇包衣在低温条件下对玉米出苗和苗期生长有较大的影响,能明显降低玉米苗期植株的根重,茎鲜重,株高,发芽率和发芽势;97%多菌灵包衣对玉米出苗和苗期生长的影响不大。因此,在生产上,97%多菌灵可以按要求包衣,防治玉米苗枯病,而98%烯唑醇种子处理时要慎重,以免低温造成药害。

几种杀菌剂对玉米苗枯病菌毒力测定及防效试验

选用7种杀菌剂对玉米苗枯病菌(Fusanummoniliforme)菌丝生长和分生孢子萌发进行了室内毒力测定和田间盆栽防效试验。毒力测定结果表明:适乐时、烯唑醇、立克秀对菌丝生长有明显的抑制作用,EC50分别为0.04、0.12和0.19μg/g。多菌灵、福美双对孢子萌发有明显的抑制作用,EC50分别为0.17和1.77μg/g。盆栽试验结果表明:适乐时、福美双拌种对玉米苗枯病有较好的防治效果,相对防效分别达到54.8%和52.3%,生产上可交替使用。