长山药冷害发生机制的研究

Study on chilling injury mechanism of yam

为了探讨长山药冷害发生机制及其品质的变化,将长山药块茎分别置于1、3、5℃条件下贮藏。通过分析贮藏期间长山药块茎的冷害指数、细胞膜透性(相对电导率)、丙二醛(MDA)含量以及POD、SOD、CAT活性的变化,探究其冷害发生机制。研究表明:长山药块茎在贮藏期间冷害出现的较晚,在1、3℃条件下贮藏到第20天时表现出冷害;随着贮藏时间的延长,温度越低冷害症状越明显,贮藏到30 d后,1℃下长山药块茎的冷害指数要显著高于3℃;而在5℃条件下长山药块茎在贮藏期间基本没有发生冷害。发生冷害的长山药块茎相对电导率和MDA含量显著高于未发生冷害组,冷害指数与相对电导率和MDA呈正相关,而POD、SOD、CAT活性要低于未发生冷害组。长山药在1、3℃下贮藏会发生冷害,长山药贮藏温度应不低于5℃。

To investigate the occurrence mechanism of chilling injury change and quality of yam, the yam was stored under different temperatures of 1 ℃, 3 ℃ and 5 ℃. After storage, the chilling injury rate, conductivity, MDA content, POD, SOD and CAT activity were measured and analyzed to study on chilling injury mechanism of yam. The result showed that the yam chilling injury appeared relatively late, the yam show symptoms of chilling injuries at 1℃ and 3 ℃ on the 20 d of storage; as the storage time was prolonged, the chilling injury extent was more severity when the temperature was lower, after storage to 30 d, the chilling injury rate at 1 ℃ was remarkably higher than at 3 ℃; yam stored at 5 ℃ did not occur chilling injury during the whole storage period. The relative electrical conductivity and MDA content of chilling injury occurred were significantly lower than not, chilling injury rate were positively correlated with conductivity and MDA content, but POD, SOD and CAT activities were significantly higher than not chilling injury. The yam occurs chilling injury at 1 ℃ and 3 ℃, so yam storage temperature should not be less than 5 1：2.