3种幼苗对水淹胁迫的生理响应

以灰木莲Manglietia glauca、木麻黄Casuarina equisetifolia、乐昌含笑Michelia chapensis幼苗为试验材料,人工模拟水淹胁迫环境,研究了水淹胁迫对这3种幼苗叶片5项生理指标的影响.结果表明,随着水淹持续时间的延长,灰木莲的叶片叶绿素含量小幅波动后急剧升降,木麻黄先微降后上升,而乐昌含笑小幅波动,峰值在(1.73±0.02)～(2.37±0.02)mg.g-1之间;灰木莲的可溶性糖含量在水淹初期下降后又回升,木麻黄则不断上升,乐昌含笑先升后降,峰值在(3.21±0.14)%～(4.96±0.34)%之间;灰木莲的蛋白质含量波动大,木麻黄小幅波动后下降,乐昌含笑先升后降,峰值在(17.97±0.83)～(28.10±2.16)mg.g-1之间;灰木莲、乐昌含笑的叶片超氧化物歧化酶(SOD)活性呈逐渐下降的趋势,而木麻黄先升高后下降,峰值在(177.39±4.86)～(183.94±1.71)U.g-1之间;灰木莲和乐昌含笑的丙二醛(MDA)含量均有上升,而木麻黄保持稳定,峰值在(0.018±0.001)～(0.037±0.002)μmol.g-1之间.主成分分析综合评价得出3个树种的抗涝性为:木麻黄>灰木莲>乐昌含笑.

Physiological Response of Three Tree Species Seedlings to Submergence Stress

In order to provide reference for selection of submergence-resistant tree species,seedling physiological changes of Manglietia glauca,Casuarina equisetifolia,and Michelia chapensis were studied under submerged stress environment.Effect of seedling physiological indexes on submergence stress was evaluated by testing contents of chlorophyll,soluble sugar,soluble protein,content of malondialdehyde(MDA) and superoxide dismutase(SOD) activity.With increasing submergence time,the chlorophyll content of M.glauca increased after slight fluctuation,that of C.equisetifolia slightly decreased followed by an increase,whereas it changed a little for M.chapensi.The peak of chlorophyll content in three seedlings was between(1.73±0.02) mg·g-1 and(2.37±0.02) mg·g-1;the content of soluble sugar of M.glauca decreased followed by an increase,C.equisetifolia continuously increased and M.chapensis increased gradually at the beginning and then decreased,and their peak was between(3.21±0.14)% and(4.96±0.34)%;the contents of soluble protein of M.glauca rapidly fluctuated,C.equisetifolia fluctuantly decreased,M.chapensis increased and then decreased,with a peak between(17.97±0.83) mg·g-1 and(28.10±2.16) mg·g-1;the activity of SOD of M.glauca and M.chapensis gradually decreased,whereas that of C.equisetifolia increased and then decreased,with a peak between(177.39±4.86) U·g-1 and(183.94±1.71) U·g-1.The content of MDA of M.glauca and M.chapensis tended to increase,whereas that of M.chapensis remained steady,with a peak between(0.018±0.001) μmol·g-1 and(0.037±0.002) μmol·g-1.The comprehensive evaluation showed that the order of submerging resistance of the three seedlings was C.equisetifolia>M.glauca>M.chapensis.