脱氧雪腐镰刀菌烯醇(DON)作为激发子对马铃薯土传病害的防治效果研究

Efficacy of Vomitoxin as Elicitor for Controlling Soilborne Diseases on Potato Plants

【目的】验证脱氧雪腐镰刀菌烯醇(DON)的安全性,探讨DON作为激发子在马铃薯主要土传病害防治中的应用效果。【方法】以大西洋品种马铃薯为研究对象,筛选DON作为激发子诱导抗病的最适质量浓度以及最佳处理时间,优化DON诱导马铃薯抗病的条件,检测生理指标的变化。【结果】结果显示低质量浓度下DON处理对马铃薯植株均无显著药害;5 ng·mL^(-1)DON处理4 h可以有效抑制青枯病致病菌茄科雷尔氏菌、软腐病致病菌菊欧氏菌、疮痂病致病菌疮痂链霉菌在马铃薯叶片中的扩展,3 ng·mL^(-1)DON处理4 h可以有效抑制干腐病致病菌接骨木镰刀菌在马铃薯叶片组织中的扩展;当温度为25℃、pH为7时DON诱导马铃薯抗青枯病、干腐病、软腐病效果最好,温度为25℃、pH为9时DON诱导马铃薯抗疮痂病效果最好;经DON诱导处理的马铃薯叶片在光照强度为12 000 lx条件下诱导抗干腐病效果最好,在光照强度为15 000 lx条件下诱导抗青枯病、软腐病、疮痂病效果最好;DON处理马铃薯叶片后,提高了SOD酶活性,同时,木质素含量增加,MDA含量减少。【结论】低质量浓度的DON作为激发子处理马铃薯叶片后对马铃薯无显著药害,在马铃薯主要土传病害防治中的应用效果较显著,可为马铃薯土传病害的预防和治理提供理论依据和新的思路。

【Objective】Safety and efficacy of applying vomitoxin to control soilborne diseases on potato plants were investigated.【Method】In a laboratory experiment,vomitoxin(aka deoxynivalenol,DON)was applied on the Atlantic variety potato to determine the disease resistance to and physiological alternations induced by some major soilborne pathogens on the plant for treatment optimization.【Result】Within a range of concentrations,DON caused no significant ill-effects on the potato plants.A treatment of it at 5 ng·mL^(-1) for 4 h effectively inhibited the spread of bacterial wilt caused by Ralstonia solanacearum,soft rots by Erwinia chrysanthemi,or scabies by Streptomyces scabies on the leaves,and at a dosage of 3 ng·mL^(-1),the growth of dry rot pathogen Fusarium sambucinum was retarded.The strongest DON-induced resistance against the bacterial wilt or dry and soft rots of the plant was found at 25℃and pH 7,and against scabies at pH 9.With an exposure of 12000 lx light,the DON-induction on the plants reached the greatest efficacy against the dry rots.Whereas,under 15000 lx,that could be achieved on the bacterial wilt,soft rots,and scabies.A DON treatment significantly raised the SOD activity and lignin content but lowered MDA in the leaves.【Conclusion】Application of DON as an elicitor in low concentrations exerted no adverse effect but significantly inhibit some major soilborne diseases on potato plants.A potential venue for preventing and treating the diseases seemed merit further investigation.