阶段性涝渍后棉花叶片几个生理指标的恢复

Recovery of physiological characters of cotton leaves after periodical water logging

为探明不同阶段涝渍胁迫解除后棉花叶片生理特性的恢复,采取池栽试验,分别在盛蕾期（6月24日~7月3日）和花铃期（7月24日~8月2日）对泗棉3号进行渍水处理,比较定型功能期叶片（T1）、迅速伸长期叶片（T2）和平展期叶片（T3）3类在渍水停止时和渍水停止后10 d叶绿素含量和硝酸还原酶活性的变化,以及在渍水停止后20d内净光合速率和整株叶片的氮素含量、可溶性糖含量和叶面积的变化特征。结果表明：盛蕾期渍水停止后5~10d 3类叶片的净光合速率逐渐达到或超过对照（正常灌水处理）,花铃期渍水停止后10~15 d 3类叶片的净光合速率达到对照水平;盛蕾期和花铃期渍水停止后10 d 3类叶片的硝酸还原酶（NR）活性均得到恢复;定型功能期叶片（T1）的叶绿素含量未得到恢复,而迅速伸长期叶片（T2）和平展期叶片（T3）的叶绿素含量则呈现明显的增长趋势;盛蕾期胁迫解除后整株叶片的含氮量得到恢复,而花铃期仍低于对照;盛蕾期和花铃期胁迫解除后叶片的可溶性糖均高于对照,但是盛蕾期在渍水停止后20 d已低于对照,花铃期叶片可溶性糖含量仍高于对照;棉花植株叶面积在渍水停止时明显降低,胁迫解除后有所增长,但达不到对照植株叶片水平。说明新生叶片在渍水处理后较容易恢复,而定型功能叶恢复难度较大,盛蕾期涝渍胁迫解除后各叶片的恢复能力较花铃期涝渍胁迫解除后各叶片的恢复能力强。

To investigate the recovery of physiological and agronomical characters of cotton leaves after periodical water logging,field experiment of water logging treatment during peak squaring stage and blooming to bolling stage was conducted on Simian 3.Cotton leaves at three stages,function stage（T1）,fast developing stage（T2） and flat stage（T3） were marked before water logging.The changes of chlorophyll content,nitrate reductase activity,net photosynthetic rate,the nitrogen content,as well as soluble sugar and leaf area of the leaves were investigated after treatment.At 10 d after water logging stress was released,nitrate reductase activities in three types of leaves were recovered,total chlorophyll content of T1 leaves did not rise up to that of control,while that of T2 and T3 leaves increased significantly.The nitrogen content of plant leaves was improved after terminating water logging at peak squring stage but it was markedly lower than that of control in blooming to bolling stage.Soluble sugar content increased significantly after water logging treatment at peak squring stage and then decreased to that of control after treatment released,while it showed little difference at blooming to bolling stage.Leaf area was reduced right after water logging and was recovered there after,but was not as good as control.It is concluded that tender leaves recovered faster than others and the recoverability of the leaves at peak squring stage was stronger than that at blooming to bolling stage.