湿度对甘薯愈伤的影响

为探索湿度对甘薯愈伤的影响,本试验以普薯32号甘薯为原料,人工模拟机械损伤后于25℃、不同相对湿度(RH50%和RH80%)条件下愈伤,通过比较甘薯木质素生成、失重率、呼吸强度、愈伤过程关键酶活性、总酚和类黄酮含量的差异,评价湿度对甘薯愈伤的影响。结果表明,RH80%条件下较RH50%更有利于甘薯愈伤木栓组织的形成,在愈伤4 d时甘薯木质素积累达到最高。与RH50%组相比,RH80%条件处理能显著提高甘薯愈伤组织苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)活性(P<0.05),提升总酚、类黄酮含量,促进呼吸高峰提前,降低甘薯重量损失。相关性分析表明,RH80%条件下愈伤,甘薯木质素含量与PAL、POD、PPO活性及总酚、类黄酮含量呈显著正相关(P<0.05)。本研究结果为甘薯采后愈伤提供了一定的理论依据。

Effect of Humidity on Wound Healing of Sweet Potato

The Pushu32 sweet potato was used as material to explore the effect of postharvest humidity on the wound healing of sweet potato. After an artificially mechanical damage, the sweet potato was stored at 25℃ under different humidity(RH50% and RH80%). The lignin accumulation, weight loss rate, respiratory intensity, key enzyme activity, total phenol and flavonoid content during the healing process of the sweet potato were measured to evaluate the effect of humidity on the wound healing of sweet potato. The results showed that RH80% enhanced the formation of healing tissues for mechanical damaged sweet potato than RH50%; lignin accumulation peaked after 4d of healing. Compared with RH50%, RH80% treatment could significantly increase the activity of phenylalanine ammonialyase(PAL), peroxidase(POD) and polyphenol oxidase(PPO)(P<0.05), elevate the content of total phenols and flavonoids, bring-forwards the respiration peak and reduce the weight loss of the sweet potato. The correlation analysis revealed a significant correlation between lignin content with PAL, POD, PPO activity, total phenol and flavonoid content under RH80% healing treatment(P<0.05). This study provides the theoretical support to the wound healing of postharvest sweet potato.