The effect of low temperature treatments on physiology characteristics and tissue structure of plums
W. Shanguang , Z. Huayun and S. Xiulan
Proceedings of 26th International Horticultural Congress. Volume of Abstract . Toronto, Canada, 11-17 August, 2002. Abstract S09-P-76. pp. 245.
2002
บทคัดย่อ
The effect mechanism of low-temperature treatments on physiology characteristic and tissue structure of “HeiHuPo” and “Chuanhong” plums was studied. The influence of four temperature patterns, (internittent warming, 0~I0? Dual temperature cycle, 0-6.6? dual-temperature cycle and decreasing temprature in sequence), on chilling injury was evaluated along with 0.5-0? Constant low-temperature storage as a matching test. The optimum temperature pattern was identifieddetermined and the mechanism of chilling injury was discussed. Result would provide theoretical suppor5 and technology reference for commercial storage of plums. This study demonstrated that –0.5~0? Constant low-temperature storage had a low temperature effect on plums. “HeiHuPo” and “Chuanhong” plums exhibited obvious chilling injury symptoms on the fortieth day of storage. With prologned storage time, chilling injury became more serious. Chilling injury promoted the increase of cell membrane permeabillity and MDA content. Cell membrane permeability was regarded as index of chilling injury in plums. The 45th and 30th day were the critical times of irreversible chilling injury in “HeiHuPO” and “chuanhong” plums. Low temperature induced an increase in PPO and POD activities decrease in phenol content, accelerater flesh browning, disturbed PG: PE enzyme balance, altered pectin metabolism, accelerated the decrease of reduced sugars and shortens shelf life of plums. It was shown through microscopy that changes occurred in tissue during the middle of the storage period: epidermis cells sank, cell wall was irregularly thickened, cells became long and the gap between cells enlarged. At the end of storage, the cuticle was broken, epidermal cells became over-overlapped, deformed and broke into pieces. Intermittent warming efficiently moderated the low-temperature effect.