| 摘要: |
| 【目的】探索不同氮素利用效率水稻品种光合生理特性的差异。【方法】采用水培法，在正常供氮（1N）和低氮（1/12N）水平下，研究4个氮高效和4个氮低效水稻品种抽穗期后部分生理指标、农艺性状及光合特性的变化。【结果】低氮水平下，氮高效水稻品种叶绿素含量、硝酸还原酶活性、可溶性蛋白质含量、地上部分干质量、株高、根长、净光合速率(Pn)、表观叶肉导度（AMC）及水分利用效率（WUE）均显著高于氮低效水稻品种；正常供氮水平下，氮高效与氮低效水稻品种上述指标的差异均未达到显著水平。与正常供氮水平相比，低氮水平下氮高效与氮低效水稻品种除根系长度和气孔限制百分率上升外，其他指标均有所下降。【结论】低氮水平下净光合速率（Pn）的下降并非来自于气孔限制因素，可能与RuBP-Case活性的下降有关。同时，氮高效水稻品种各项生理指标均优于氮低效水稻品种，说明氮高效水稻品种更能适应低氮环境，且低氮条件有利于根系的生长。 |
| 关键词: 水稻 氮 生理特性 光合特性 |
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| 基金项目:国家自然科学基金项目(31171478)；吉林省科技厅重点项目（20080201）；吉林省自然科学基金项目(201215183)；吉林省教育厅重点项目（2012044） |
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| Photosynthetic physiological characteristics of rice varieties with high nitrogen use efficiencies |
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AN Jiu-hai,LIU Xiao-long,XU Chen,et al
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| Abstract: |
| 【Objective】The study aimed to explore photosynthetic physiological characteristics of rice varieties with different N-use efficiencies.【Method】The hydroponic culture experiment was carried out to analyze changes of physiological and agronomic traits and photosynthetic characteristics of 4 rice varieties with high N-use efficiencies and 4 varieties with low N-use efficiencies under normal nitrogen (1N) and low nitrogen (1/12N) levels after heading.【Result】At low nitrogen level,the chlorophyll contents, nitrate reductase activity,soluble protein contents,dry-weight of aboveground,plant height,root length,net photosynthetic rate (Pn),apparent mesophyll conductance (AMC) and water use efficiency (WUE) of high N-use efficiency rice varieties were significantly higher than those of low N-use efficiency rice varieties,but they had no significant difference in each index at normal nitrogen level.Percentages of stomatal limitation (Ls) and root length of high and low N-use efficiency rice varieties increased with low nitrogen level,but other indexes all declined.【Conclusion】At low nitrogen level,the decline of Pn was caused by non-stomatal limitation,which may be related to decrease of RuBP-Case activity.Physiological indexes of high N-use efficiency rice varieties were higher than those of low N-use efficiency rice varieties,indicating that high N-use efficiency rice varieties could better adapt to low nitrogen environment,and low nitrogen condition is conducive to root growth. |
| Key words: rice nitrogen physiological characteristics photosynthetic characteristics |
