低剂量短波紫外线辐照对采后马铃薯块茎愈伤的促进作用

Promoting effect of low-dose ultraviolet-C Irradiation on wound healing of postharvest potato tubers

为研究短波紫外线(Ultraviolet-C,UV-C)辐照对采后马铃薯块茎愈伤的促进效果及生化机制,采用不同剂量(0.1、0.3、0.5 kJ/m^(2))的UV-C辐照处理模拟损伤的‘玉田806号’马铃薯块茎,通过测定损伤块茎愈伤期间的品质及关键生化指标的变化来评价UV-C对马铃薯的愈伤效果。研究发现,0.3 kJ/m^(2)和0.5 kJ/m^(2)剂量的UV-C辐照在愈伤后期可加速马铃薯伤口腐烂,而0.1 kJ/m^(2)UV-C处理和对照组的马铃薯在整个愈伤期间未出现腐烂现象,对块茎的愈伤效果最佳。此外,UV-C辐照可通过提高马铃薯块茎伤口处的苯丙氨酸解氨酶(Phenylalanine ammonia lyase,PAL)活力,有效增加伤口处总酚和类黄酮的含量;通过促进块茎伤口处过氧化物酶(Peroxidase,POD)活性和H_(2)O_(2)含量,显著加速了木质素和软木脂在伤口处的积累和沉积,从而极大增强了损伤块茎的硬度,降低了愈伤期间损伤块茎的失重率。低剂量UV-C辐照(0.1 kJ/m^(2))促进马铃薯块茎愈伤的效果,为开发新型马铃薯促愈技术提供了理论依据。

In order to investigate the promotion effect and biochemical mechanism of ultraviolet-C(UV-C)irradiation on wound healing of postharvest potato tubers,artificially injured potato tubers(Yutian 806)were treated with different low doses(0.1,0.3,0.5 kJ/m~2)of UV-C irradiation.The wound healing effect of UV-C was evaluated by measuring the changes of quality index and the key biochemical indexes during wound healing.It was found that 0.3 kJ/m~2 and 0.5 kJ/m~2 UV-C irradiation could accelerate the decay of the wounded potato in the later stage of healing,while no decay occurred in potatoes of 0.1 kJ/m~2 group and CK group throughout the healing period.In addition,UV-C irradiation could effectively increase the content of total phenols and flavonoids at the wound site of tubers by increasing phenylalanine ammonia lyase(PAL)activity.In addition,UV-C significantly accelerated the accumulation and deposition of lignin and suberin at the wound site of potato tuber by promoting peroxidase(POD)activity and H_2O_(2)content,thus accelerating the wound healing and maintaining lower weight loss and higher firmness.Overall,UV-C irradiation can promote wound healing of potato tuber,which provides a theoretical basis for the development of novel potato healing technology.