高温处理对采后山药块茎愈伤和抗病性的影响

Effects of high temperature treatment on callus and disease resistance of postharvest yam tubers

以菜山药(Dioscoreae rhizoma)为材料,人工造伤后分别在5、15、25、35℃下处理7d,研究采后不同温度处理对损伤山药采后组织结构、失重和抗病性、活性氧代谢、酚类物质代谢等相关抗病性指标的影响。结果显示:在5~35℃范围内,随着处理温度的升高,伤口切面积累木栓质聚酚和木质素,以35℃高温处理组积累最早且积累最多;同时35℃愈伤处理的山药块茎失重率和发病程度显著降低,过氧化氢含量、超氧阴离子产生速率和超氧化物歧化酶、过氧化物酶活性显著高于其他温度处理组;总酚、总黄酮含量、多酚氧化酶、苯丙氨酸解氨酶活性显著高于其他温度处理组。上述研究结果表明,35℃高温处理采后菜山药可以提高其块茎活性氧代谢和酚类物质代谢水平,有效促进山药块茎采后损伤的愈合和抗病性,减少采后腐烂。

In this experiment,artificially wounded yam tubers were treated at 5 ℃,15 ℃,25 ℃ and 35 ℃ for 7 days,respectively.The effects of different temperature treatments on the post-harvest tissue structure,weight loss and disease resistance,disease resistance indicators related with metabolism of active oxygen and phenolic substance were studied.The results showed that in the range of 5-35 ℃,the corrugated polyphenols and lignin were accumulated in the wound section with the increase of treatment temperature.The treatment group with the high temperature of 35 ℃ accumulated the earliest and accumulated the most.The weight loss rate and incidence of yam tuber treated with callus at 35 ℃ were significantly reduced.The contents of hydrogen peroxide,total phenols and flavonoids,the production rate of superoxide anion,and activities of superoxide dismutase,peroxidase,polyphenol oxidase and phenylalanine ammonia lyase of the yam tuber under 35 ℃ were the highest among the treatments.It is indicated that the high temperature treatment of postharvest yam at 35 ℃ can improve the metabolism of active oxygen and phenolic of yam tubers,effectively promote the healing and disease resistance of yam tuber postharvest damage,and reduce postharvest rot.