短时间冰冻低温处理下活性氧代谢与桃芽自然休眠解除研究(英文)

以7a生曙光油桃为试材,通过冰冻低温处理枝条,研究了不同温度和时间对桃芽的存活率、萌芽级数和活性氧含量及其相关酶活性的影响,并探讨对桃芽自然休眠的调控效应。结果表明,短时间冰冻低温处理对桃芽自然休眠解除的调控效应因处理时期、处理温度和处理持续时间长短的不同而异。3个不同采样时期,短时间冰冻处理中,-4℃和-7℃处理对油桃芽休眠解除的效应不明显,桃芽中H2O2(过氧化氢)含量、O·2(超氧阴离子自由基)产生速率和·OH(羟基自由基)产生速率及POD(过氧化物酶)、CAT(过氧化氢酶)和SOD(超氧化物歧化酶)活性与对照相比差异不大;但-10℃、-13℃、-16℃、-19℃和-21℃各处理对油桃芽休眠解除呈正调控效应,桃芽内除SOD活性显著降低外其它指标都明显升高;但是采样时期越晚,调控效应越明显。H2O2含量、O·2和·OH产生速率的显著增加表明短时间冰冻处理可有效解除芽自然休眠,并且活性氧的迅速增加可能是短时间冰冻处理解除芽自然休眠的重要因素。

A study on active oxygen metabolism and endodormancy release in nectarine bud treated by short-term freezing

Bud livability, budburst, active oxygen production and activities of related enzymes in Shuguang nectarine (Prunus persica var. Nectarina Maxim. Cv. Shuguang) shoots exposed to seven short-term freezing temperatures at three expo- sure durations were studied in order to understand the mechanism of endodormancy release by short-term freezing. The re- sults showed that the effects of short-term freezing on endodormancy varied with the date of treatment, temperatures and ex-posure time. Among the three different dates, treatments at -4℃ and -7℃ had no significant effect on budbreak, and O2·- and · OH production rates, concentration of H2O2 and the activities of CAT, SOD and POD enzymes at -4 ℃ and -7℃had no significant difference from the control. Freezing temperatures at -10 ℃ or lower significantly increased budbreak, O2·- and·OH production rates, concentration of H2O2 and the activities of CAT and POD enzymes but reduced SOD activity. Later short-term freezing treatments produced better dormancy-releasing effects. The correlation between budburst and reactive oxygen species among different treatments indicated that a significant accumulation of reactive oxygen species was probably important for endodormancy release.