华南地区4种阔叶幼苗水分胁迫条件下的抗旱性初探

Preliminary Study on Drought Resistance of Four Broadleaved Seedlings under Water Stress in South China

以火力楠、山杜英、木荷、黧蒴锥幼苗为试验材料,利用聚乙二醇6000(PEG-6000)人工模拟水分胁迫环境,研究了水分胁迫对这4种幼苗的影响。结果表明:随着水分胁迫强度的增加,火力楠和木荷叶片的相对含水量下降幅度较小,山杜英次之,黧蒴锥下降幅度最大;火力楠和木荷叶片的相对电导率上升幅度较小,山杜英次之,黧蒴锥叶片的相对电导率大幅增加;火力楠和木荷幼苗叶片脯氨酸含量变化不大,而山杜英和黧蒴锥比对照有明显的增加;4种幼苗叶片的可溶性糖含量随着水分胁迫强度的增加呈上升趋势;4种幼苗叶片的叶绿素含量一般呈小幅波动;重度胁迫36 h后,火力楠和木荷叶片的SOD活性显著提高,山杜英显著低于对照,黧蒴锥接近对照水平;火力楠叶片的MDA含量略有增加,木荷保持稳定,山杜英明显增加,黧蒴锥大幅增加。用主成分分析评价4种幼苗的抗旱性,结果表明:4种幼苗的抗旱性为木荷>火力楠>山杜英>黧蒴锥。

The drought resistance of Michelia macclurei,Elaeocarpus sylvestris,Schima superba and Castanopsis fissa seedlings was studied under artificial simulated water stress by using PEG-6000.The results are as follows： With the water stress increasing,the decrease of relative water contents in leaves of M.macclurei and S.superba seedlings was relatively small,followed by E.sylvestris,whereas that of C.fissa was the largerest.The relative conductivities of leaves of M.macclurei and S.superba seedlings increased slightly,followed by E.sylvestris,whereas that of the C.fissa increased greatly.The contents of free proline in leaves of M.macclurei and S.superba changed a little,whereas those of E.sylvestris and C.fissa increased significantly compared to the controls.The contents of soluble sugar in leaves of the four seedlings tended to increase with increasing stress intensity;the chlorophyll contents in leaves of the four seedlings fluctuated slightly with increasing stress intensity;the activities of SOD in leaves of M.macclurei and S.superba seedlings were significantly greater than that of the controls,and that of E.sylvestris was significantly smaller than the control,whereas that of C.fissa seedling was close to the control under severe stress with 36 hours.The content of MDA slightly increased for M.macclurei seedling,significantly increased for E.sylvestris seedling,kept steady for S.superba seedling and greatly increased for C.fissa seedling.The drought resistance of the four seedlings was evaluated with principal component analysis,indicating that their drought resistance was in the order of t S.superbaM.macclureiE.sylvestrisC.fissa.