弗吉尼亚栎幼苗对高温胁迫的生理响应

摘要

Seedlings of Quercus virginiana were heat⁃stressed under 35 ℃ and 45 ℃ with different peri⁃ods.The changes of leaf water content,electrolyte leakage,MDA content and proline content were measured.The results showed that the leaf water content of Quercus virginiana seedlings decreased gradually with extending of stress time;whilst other indexes first increased with stress time then decreased.The electrolyte leakage signifi⁃cantly increased after 12 h stress treatment and it could not drop back during the recovery.While other four in⁃dexes basically showed a good recovery to the level of the control group after 72 h recovery growth at 25 ℃. This indicates that Quercus virginiana has a relatively good resistance and adaptability to high temperature stress.%弗吉尼亚栎幼苗经过35℃和45℃不同时间的高温胁迫处理后，测定叶片含水量、电解质外渗率、MDA含量、脯氨酸含量等生理指标的变化。结果表明，在高温胁迫下，弗吉尼亚栎植株叶片含水量随着胁迫时间的延长而降低，其他几项生理指标基本表现为先升高后降低的趋势，其中电解质外渗率在高温胁迫处理12 h后即显著升高，并且在恢复生长过程基本没有下降。叶片含水量、MDA、脯氨酸含量等指标在高温胁迫不同时长处理后，经过25℃、72 h的恢复生长后大多可以恢复至处理前水平，表明弗吉尼亚栎对高温胁迫具有较强抗性和适应性。