高温及持续时间对华北落叶松SOD、POD活性的影响

【研究目的】研究了高温对华北落叶松保护酶活性影响规律，旨在为育苗和养护工作提供理论依据。【方法】设置W1（25℃ 对照）、W2（30℃ ）、W3（35℃ ）、W4（40℃ ）4个处理，温度处理持续时间设置为1、3、5、7、9、11 h。【结果】W4叶片内SOD活性5 h后均显著高于对照；茎内SOD活性W2、W3、W4处理在5 h处理下均与对照之间存在显著差异，11 h时，3个处理分别比对照降低了12.61%、1.93%、26.64%；根系内SOD活性W2、W3、W4的5、7 h处理均显著高于对照，11 h处理分别比对照降低了8.35%、5.99%、28.47%；叶片内POD活性W4的3、5 h处理分别比对照提高了109.75%、20.11%，差异显著；茎内POD活性11 h处理W3比对照提高了40.16%，差异显著；根系POD活性W4在5 h时达到最高值。【结论】华北落叶松35℃以上高温持续时间不宜超过5 h。

High Temperature and Its Duration: Effect on SOD and POD Activity of Larix principis-rupprechtii

The effect of high temperature on protective enzyme activity of Larix principis-rupprechtii is studied to provide a basis for seedling cultivation and forest conservation. We set 4 treatments as W1 (25℃ control), W2 (30℃), W3 (35℃), W4 (40℃), and set the duration of the temperature treatment as 1, 3, 5, 7, 9, 11 h. The results showed that: the SOD activity of leaves under W4 was significantly higher than that of control after 5 h; the SOD activity of stems under W2, W3 and W4 treatments were significantly different with that of control after 5 h, at the same time, the SOD activity of stems under the 3 treatments were lower than that of control by 12.61%, 1.93%, 26.64% after 11 h; the SOD activity of roots under W2, W3, W4 treatments were significantly higher than that of control after 5, 7 h, and, the SOD activity of roots under the 3 treatments was lower than that of control by 8.35%, 5.99%, 28.47% after 11 h; the POD activity of leaves under W4 was higher than that of control by 109.75%, 20.11% after 3,5 h and the difference was significant; the POD activity of stems under W3 was higher than that of control by 40.16% after 11 h and the difference was significant; the POD activity of roots under W4 reached the highest value after 5 h. The high temperature duration above 35℃ should not exceed 5 h for Larix principis-rupprechtii.