Abstract:

Free polyamine levels (spermine (SPM), spermidine (SPD), and putrescine (PUT)) were determined using thin-layer chromatography and fluorometric method in loquat (Eriobotrya japonica Lindl. cv. Dahongpao) fruits stored at 1℃ and 12℃ and in postharvest SPM treated fruits stored at 1℃ respectively to investigate the relationship between changes in polyamines and chilling injury. In the loquat fruits stored at 1℃, SPM level decreased gradually in the first two weeks, then increased sharply and reached a peak value after three weeks, thereafter it decreased rapidly. SPD level decreased steadily during the first three weeks and increased significantly afterwards. PUT level evolved in a similar way as the SPM level did except that it increased slowly in the first two weeks. The fruit showed symptom of chilling injury manifested as flesh leatheriness after three weeks. However, no significant increase and decrease of these three polyamines was detected during storage at the nonchilling temperature (12℃). The SPM-treated fruits maintained high levels of SPM and SPD and remained low level of PUT during storage at 1℃, and no symptom of chilling injury was observed. These results suggested that the increase in SPM level in response to chilling exposure might serve as a defense mechanism against chilling injury while the accumulation of PUT could be a cause of the stress-induced injury and the increase in SPD level could be a consequence of this kind of stress.

多胺与枇杷果实冷害的关系
郑永华¹ 李三玉² 席王与芳² 苏新国¹ 易云波¹

（1. 南京农业大学食品科技学院，南京210095；2.  浙江大学园艺系，杭州310029）

摘要：应用薄层_荧光法测定多胺含量以研究其与枇杷 (Eriobotryajaponica Lindl.cv .Dahongpao)果实冷害的关系。果实在 1℃下贮藏时 ,精胺 (SPM)和亚精胺 (SPD)含量逐渐下降 ,但SPM在 2周后迅速回升并于第 3周时达到高峰 ,随后又迅速下降 ,SPD在 3周后持续反弹上升。腐胺 (PUT)含量在前 2周缓慢上升 ,2周后迅速积累并于第 3周时形成高峰 ,随后也迅速下降 ,贮藏 3周后的果实出现明显的冷害症状。在非冷害温度 1 2℃下贮藏时 ,多胺含量波动较小。外源SPM处理可保持较高的内源SPM和SPD水平 ,抑制PUT积累和冷害发生。这些结果表明 ,枇杷果实低温贮藏时SPM含量的升高可能是果实对冷害的防卫反应 ,PUT的积累可能是冷害的原因 ,SPD含量的上升则可能是冷害的结果。

关键词： 枇杷果实；多胺；冷害

Key words: Eriobotrya japonica , polyamines, chilling injury