细叶百合冷藏过程中鳞茎保护酶活性与休眠解除的关系

以细叶百合为试材,通过冷藏(5℃)解除鳞茎休眠,研究了细叶百合鳞茎解除休眠过程中鳞茎保护酶活性与糖代谢的变化规律。结果表明,鳞片、顶芽及鳞茎盘SOD活性在冷藏0~24 d内下降,除顶芽外,鳞茎各部位POD活性在0~24 d内呈下降趋势,外鳞片、顶芽及鳞茎盘中CAT活性在冷藏0~12 d内下降,冷藏中后期,SOD、CAT、ASP活性升高,鳞片中POD的活性下降,顶芽及鳞茎盘POD、PPO在冷藏中期上升。各种代谢相关酶在不同器官中的作用并不完全相同。在低温处理36~60 d内,ASP、CAT活性快速上升,后期趋于稳定。SOD活性最低点出现在冷藏36~60 d,鳞茎各部位淀粉与CAT、PPO、ASP均表现为负相关性,SOD、POD、PAL与鳞片中淀粉表现为正相关性。36 d是鳞茎解除休眠的起点,60 d时鳞茎基本解除休眠。

Relationship between dormancy breaking and protective enzymes in refrigerated Lilium pumilum bulbs

Changes in bulb protective enzyme activity and carbohydrate content of Lilium pumilum bulbs held at 5℃ to break dormancy were investigated.Results showed that superoxide dismutase (SOD)activity of scales,apical buds and basal plates decreased within 0 - 24 days (d).Except for apical buds,peroxidase (POD)activity within 0-24 d declined in all bulb parts and catalase (CAT)activity of the outer scales,apical buds and basal plates decreased within 0 -12 d.During middle and later periods,SOD,CAT and ascorbate peroxidase (ASP)increased,POD activity decreased,POD and polyphenol oxidase (PPO)activity of apical buds and basal plates also increased in the middle of the cold storage period.The roles of various metabolism related enzymes in different organs were not the same.With low temperature treatment for 36-60 d,ASP and CAT activity initially rapidly increased but later stabilized.The minimum value of SOD activity was found after 36-60 d cold storage.Starch content was negatively correlated with CAT,PPO,ASP,SOD and POD in all bulb parts;phenylalanine ammonia lyase (PAL)was positively correlated with starch in the scales.Bulb dor-mancy breaking started at 36 d,and was mostly complete at 60 d.