中国芒幼苗对土壤干旱胁迫的生理响应

Physiological Responses of Miscanthus sinensis Seedlings to Soil Drought Stress

[目的]探讨中国芒幼苗对土壤干旱胁迫的生理响应.[方法]以中国芒幼苗为试验材料,对其在土壤干旱胁迫及复水条件下的生理特性进行了研究.[结果]轻度土壤干旱胁迫（处理1,10 d后复水）在胁迫初期,各指标均呈逐渐升高的趋势,复水后各指标与CK保持相对稳定;中度土壤干旱胁迫（处理2,15 d后复水）在胁迫初期,各指标显著升高,复水后,MDA、相对电导率、APX、GR均有所回升,SOD、POD、CAT、ASA、GSH降低速度变缓,但仍显著高于CK组;重度干旱胁迫（处理3,持续干旱胁迫）在胁迫处理初期,各指标显著升高,干旱胁迫后期,MDA、相对电导率继续升高,SOD、POD、CAT、APX、GR、ASA、GSH急剧下降,并显著低于CK.[结论]芒幼苗忍受土壤干旱胁迫的极限时间是20d,最佳复水时间是10 ～ 15 d.

[Objective] The study aimed to discuss the physiological responses of Miscanthus sinensis seedlings to soil drought stress.[Method] The effect of soil drought stress on physiological properties of M.sinensis was studied.[Result] All indexes of M.sinensis rose at the earlier stage of light drought stress and recovered to a similar level of the control after M.sinensis seedlings were watered ; at the earlier stage of moderate drought stress,all indexes of M.sinensis increased significantly,but MDA,relative conductivity,APX and GR activity recovered after the seedlings were watered,while SOD,POD,CAT,ASA and GSH decreased more slowly; at the earlier stage of severe drought stress,all indexes of M.sinensis enhanced significantly,but at the later stage of severe drought stress,MDA and relative conductivity continued to rise,SOD,POD,CAT,APX,GR,ASA and GSH decreased significantly and lower than those of CK.[Conclusion] The limit time of M.sinensis seedlings standing drought stress was 20 d,and the best watering time was 10-15 d.