采后水杨酸处理对马铃薯块茎愈伤的促进及部分机理研究

Effects of Postharvest Salicylic Acid Treatments on Wound Healing of Potato Tubers and its Partial Mechanism

本研究以"青薯168"马铃薯块茎为试材,研究4mmol/L水杨酸浸泡处理对马铃薯块茎愈伤效果的影响及部分机理。结果表明,4mmol/L水杨酸处理有效降低了损伤接种块茎的病情指数,减少了愈伤期间块茎的失重,处理块茎组愈伤第5d的失重率和病情指数分别比同期对照低44.27%和46.70%。水杨酸处理还明显促进了愈伤组织中H_2O_2的积累,提高了过氧化物酶的活性,SA处理后第3d,块茎H_2O_2含量和POD活性分别比同期对照高55.33%和6.91倍。此外,水杨酸处理有效促进了愈伤组织中木质素和软木脂的积累,处理后第14d,处理组愈伤组织木质素和软木脂积累的细胞层数均比同期对照增加了2层。由此表明,采后4mmol/L水杨酸浸泡处理可促进采后马铃薯块茎的愈伤,其对愈伤组织形成的促进作用是活性氧代谢和苯丙烷代谢增强的共同作用结果。

Potato tubers（Solamum tuberosum L. cv, Qingshu 168） were used as materials in this paper. Tubers were dipped with 4 mmol/L salicylic acid（SA） for 10 min. The effects of SA treatment on wound healing of potato tubers and it＇s partial mechanism were investigated. The results showed that SA treatment effectively reduced the increase of weight loss and disease index, the weight loss and disease index of the treated tuber were 44.27%and 46.70% lower than that of the control after 5 days of the treatment. SA treatment also significantly promoted the accumulation of hydrogen peroxide（H2O2） and the increase of peroxidase（POD） activity in callus., 55.33%higher of H2O2 content and 6.91 times raise of POD activity were occurred compared with the control after 3 days of treatment. Meanwhile, the accumulation of callus lignin and suberin were increased after treatment. The number of callus cell layers where lignin and suberin deposited were both 2 more than that of the control after 14 days of treatment. It suggested that postharvest SA treatments can promote wound healing of potato tuber by improving callus formation which results from enhancement of the reactive oxygen species and phenylpropanoid pathway metabolism.