贮藏期甘薯损伤对愈伤后表皮生理特性及贮藏品质影响

Effects of Sweet Potato Injury During Storage on Physiological Characteristics and Storage Quality after Callus

旨在明确愈伤处理对贮藏期甘薯品质影响,为甘薯高质量贮藏提供理论基础。通过对2种鲜食型甘薯心香与烟薯25分别进行贮藏,在不同的贮藏期(0,7,15,30,60,90 d)分别取样,在贮藏期设置不同程度的模拟损伤,分别为对照、高温愈伤、浅层损伤后愈伤、深层损伤后愈伤。愈伤条件为相对湿度85%,室温35℃的培养箱中愈伤48 h,随后测定接种软腐病病原菌后的发病病斑直径,表皮防御酶活性(PPO、POD、PAL),薯块淀粉、蛋白质、可溶性糖等营养物质含量变化。结果表明,随着贮藏期延长,甘薯块根接种软腐病病菌后病斑直径增大。经过愈伤处理的甘薯较普通环境贮藏的甘薯具有更强的软腐病抗性。贮藏至90 d,2个品种薯块受到浅层损伤愈伤后处理的病斑扩散直径仅为对照处理的74.6%,71.1%。贮藏前期0~30 d各处理防御酶活性均保持较高水平。贮藏后期90 d 2个品种损伤处理愈伤后防御酶活性均显著高于对照处理,贮藏期60 d 2个品种块根受到损伤愈伤后蔗糖含量显著高于对照处理。贮藏期甘薯在受到不同程度的损伤后经过愈伤处理可以显著提升甘薯表皮的防御酶活性,降低感染软腐病后病菌扩散速度,提高甘薯的软腐病抗性。损伤程度对甘薯愈伤效果存在影响,受到浅层损伤愈伤后在防御酶活性及贮藏品质方面均优于受到深层损伤后愈伤的甘薯。

To clarify the effect of callus treatment on the quality of sweet potato,provide a theoretical basis for high quality storage of sweet potato.Two edible varieties of sweet potato were stored and taken at different storage periods(0,7,15,30,60 and 90 d).Different degree of injury were carried out on them.The experiment was divided into four treatments:CK,high temperature callus,callus after shallow injury,and callus after deep injury.Then put materials in an incubator with relative humidity of 85%at 35℃for 48 h to healing the wound.The diameter of soft rot spots,the activity of epidermal defense enzymes(PPO,POD,PAL)and the content of nutrients in potato pieces were measured.The results showed that the spot diameter of sweet potato root increased with the extension of storage period after inoculation of Rhizopus stolonifera.Sweet potato treated with callus was more resistant to soft rot than sweet potato stored in ordinary environment.After storage for 90 days,the diffusion diameter of soft rot spots of the two varieties after callus treatment with shallow injury was only 74.6%and 71.1%of that of the control treatment.At the early stage of storage,the activity of defense enzymes in each treatment remained at a high level from 0 to 30 d.After 90 d of storage,the activity of defense enzymes after callus injury treatment was significantly higher than that of control treatment.At 60 d of storage,the sucrose content of root tuber of two varieties with treatments of callus after shallow and deep injury was significantly higher than that of CK.Callus treatment of sweet potato after different degrees of injury during storage period can significantly increase the activity of defense enzymes in sweet potato epidermis,reduce the spread speed of soft rot infection,and improve the resistance of sweet potato to soft rot.The degree of injury had influence on the callus effect of sweet potato.The callus after shallow injury was better than that of deep injury in terms of defense enzyme activity and storage quality.