| 摘要: |
| 【目的】研究水分胁迫后复水对糜子根、冠生长和光合作用的补偿规律及补偿条件的影响，为糜子抗旱节水栽培和补偿效应研究提供理论依据。【方法】采用盆栽控水方式，以全生育期正常供水为对照，分别在糜子不同生育时期水分胁迫后复水，对复水后糜子根、冠功能的恢复以及复水前后新老叶片净光合速率等指标进行分析。【结果】（1）水分胁迫后复水，根冠功能和光合作用的补偿效应与胁迫持续时间、胁迫程度及复水时期有关。（2）三叶一心期水分胁迫复水后，重度胁迫拔节期复水处理的根冠比、根系伤流量和叶面积的恢复最快，分别高于对照和中度胁迫拔节期复水处理；同时，拔节期复水处理各指标的补偿效应高于抽穗期复水的2个处理。拔节期水分胁迫复水后，中度胁迫抽穗期复水处理的根冠比、根系伤流量和叶面积高于对照和重度胁迫复水处理。（3）与对照相比，无论是三叶一心期还是拔节期开始水分胁迫，胁迫前生长出的叶片复水后其净光合速率低，胁迫程度越重净光合速率越小；而复水后长出的新叶，三叶一心期重度水分胁迫拔节期复水处理新叶净光合速率最高，复水20 d时比对照高出14.5%，中度水分胁迫拔节期复水后新叶净光合速率与对照无显著差异。【结论】三叶一心期重度水分胁迫拔节期复水有利于新生器官生理活性的提高，对糜子根冠功能和净光合速率的补偿效应最佳。 |
| 关键词: 糜子 水分胁迫 复水 根冠功能 净光合速率 补偿效应 |
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| 基金项目:国家自然科学基金项目（31371529）；国家谷子糜子产业技术体系项目（CARS-07-12.5-A9） |
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| Compensation effects of rewatering on root and shoot functions of broomcorn millet after water stress |
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ZHAO Wei-jie,LI Cui,ZHOU Da,et al
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| Abstract: |
| 【Objective】Effects of rewatering on compensation mechanism and condition of root and shoot growth as well as shoot photosynthesis rate (Pn) of broomcorn millet were studied to provide basis for water saving cultivation of broomcorn millet.【Method】Taking adequate water supply as CK,pot experiment was conducted to rewater after water stress at different growth periods.The root and shoot characteristics and Pn of new and old leaves before and after rewatering were measured and analyzed.【Result】（1）Compensation effects of root and shoot functions as well as Pn correlated with the duration and intensity of water stress and rewatering time.（2）When water control was conducted from 3-leaf stage and rewatering was implemented from jointing stage,root to shoot ratio,root extrudes volume and leaf area of broomcorn millet under severe water stress increased faster than that of the CK and the treatment under moderate water stress.Besides,compensation effects of tested items were stronger compared with the two treatments when rewatering was conducted from heading stage.When water control was implemented from jointing stage and rewatering was conducted from heading stage,root to shoot ratio,root extrudes volume and leaf area of broomcorn millet under moderate water stress were larger than that of the CK and the treatment under severe water stress.（3）When water control was conducted from 3-leaf stage or from jointing stage,Pn of original leaves before water control was lower than that of the CK,and fiercer stress led to lower Pn.While for the new leaves after rewatering,Pn after rewatering from jointing stage under severe water stress from 3-leaf stage was the highest,14.5% higher than that of the CK 20 days after rewatering.When water stress was moderate,no significant difference was found between Pn of new leaves and that of the CK.【Conclusion】Rewatering after early stage severe water stress was beneficial for the enhancement of physiological activities of the new organs,and the compensation effects for root and shoot growth as well as shoot photosynthesis were optimum. |
| Key words: broomcorn millet water stress rewatering root and shoot functions Pn compensation |
