不同小麦品种氮效率与氮吸收对氮素供应的响应及生理机制

Responses and corresponding physiological mechanisms of different wheat varieties in their nitrogen efficiency and nitrogen uptake to nitrogen supply

以具有典型特征的不同氮效率小麦品种为材料,研究了低氮和高氮条件下小麦的生物学性状、生理参数和氮同化代谢酶活性.结果表明:低氮条件下,不同氮效率小麦品种根系干质量、茎叶干质量、植株氮累积量基本上为氮高效品种>中效品种>低效品种.低氮条件下,氮吸收高效品种(冀97-6360)的根系活跃吸附面积、TTC还原力、叶片硝酸还原酶活性和叶片NO3-含量最大;生理高效品种(石新5418)具有较高的叶片亚硝酸还原酶活性和谷氨酰胺合成酶活性,较低的植株全氮含量、叶片NO3-含量和硝酸还原酶活性.低氮条件下植株氮利用效率与氮吸收系数显著相关.不同小麦品种在高氮条件下的生物学性状、生理参数和氮同化代谢酶活性与低氮条件下不尽一致.

In this paper, the biological traits, physiological parameters, and enzyme activities related to N assimilation and metabolism of wheat varieties with different nitrogen （N） efficiency were studied under low and high N supply. The results showed that under low N supply, the dry mass of root, leaf, and stem as well as the accumulated N amount in plant were in the order of high N efficiency variety 〉 mid N efficiency variety 〉 low N efficiency efficiency （Ji 9745360） under low N supply had the highest variety. The variety with high N uptake root active absorption area and TTC-reductive activity and the highest leaf nitrate reductase activity and NO3^ - content, while the variety with high N physiological efficiency （Shixin 5418 ） had higher nitrite reductase and glutamine synthetase activities but lower NO3 - content and NR activity in its leaf. There was a significant positive correlation between nitrogen use efficiency （NUE） and nitrogen uptake index （NUI） under low N supply. The biological traits, physiological parameters, and enzyme activities related to nitrogen assimilation and metabolism of test wheat varieties were not always the same under high and low N supply.