Physiological mechanism of inducers to resistance inducing of potato scab

ObjectiveThe effects of different inducers on inducing resistance of potato scab and resistant physiologi-cal mechanism were explored to provide reference for biological control methods of the potato scab.MethodSix diffe-rent treatments were conducted,while spraying clear water on leaves was as control(CK). Treatment 1-treatment 4 were seed dressing+1.0 mmol/L salicylic acid foliage spraying,seed dressing+1.0 mmol/L benzothiodiazole foliage spraying, seed dressing+2000 times 25% pyraclostrobin foliage spraying and seed dressing+500 times 3% amino oligosaccharide foliage spraying. Treatment 5 and treatment 6 were 50 times 3% amino oligosaccharide seed spraying+500 times 3% amino oligosaccharide foliage spraying and 50 times 3% amino oligosaccharide seed spraying+500 times 3% mushrooms poly-saccharide foliage spraying. Spraying once every 7 d and three times in total. After 14 d of the third spraying,the germi-nating rate,plant height and other agronomic characters were investigated,and the physiological indexes of resistance were measured. After the harvest,the incidence and yield of tuber scab were studied and quality analysis was conducted.ResultThe treatment of different inducers could all significantly reduce the incidence of potato scab,and 50 times 3% amino-oligosaccharide(AO)seed dressing and 500 times 3% lentinan(LNT)foliage spraying had the best control efficien-cy(68.85%). Treatment of inducers could increase leaf chlorophyll,content of soluble sugar and soluble protein,and the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT),malonaldehyde(MDA)content was re-duced,but soluble protein,vitamin C and starch content of tubers were significantly improved compared with CK(P<0.05).ConclusionThrough increasing content of chlorophyll and osmoregulation substances,inducers can enhance the activity of oxidase system and reduce cellmembranes lipid peroxidation to regulate plant growth,thus inducing plants to produce systemicresistance. The optimal inducers of preventing potato scab is 50 times 3% amino-oligosaccharide seed dressing+500 times 3% lentinan foliage spraying,which can improve the yield and the nutritional quality of tubers.