不同糜子品种对低氮胁迫的生物学响应

采用溶液培养的方法，研究了低氮胁迫下不同糜子品种苗期生物学性状、 氮素吸收利用效率差异及与根系形态生理指标之间的相关关系。 结果表明， 低氮胁迫下，糜子地上部生长受抑程度大于根部，植株氮累积量降低但氮利用效率明显提高。晋黍7号株高、 叶面积、 茎叶干重、 根干重、 总根数、 总吸收面积和活性吸收面积下降幅度在所测试品种中均最小, 其总氮累积量分别是晋黍1号、 晋黍5号、 晋黍8号的1.35、 1.50、 1.39倍，根系氮累积量/总氮量的百分率增加的幅度和地上部氮累积量/总氮量的百分率下降的幅度均最低，分别为9.75% 和 3.47%; 植株氮利用效率比晋黍1号、 晋黍5号、 晋黍8号分别高20.92%、 12.44%、 14.83%。晋黍7号较其他品种更耐低氮胁迫。低氮胁迫下，糜子根系干重、 总根长、 总吸收面积与总氮累积量呈显著线性相关，表明低氮胁迫下，根系形态生理指标对氮素吸收效率起重要作用。

Biological response of different cultivars of millet to low nitrogen stress

 A solution culture experiment was carried out to study the biological trait,  the different responses in N uptake and utilization efficiency of four cultivars of millet under low nitrogen stress,  the correlation between N uptake and morphological and physiological traits of root system were also discussed. The results show that under low nitrogen stress,  the shoot growth of millet was restrained earlier than roots. The N uptake was decreased,  but the general efficiency of N increased drastically. The mildest restrain in plant height,  leaf area,  shoot and root dry weight,  total root length,  root number,  total and active uptake area was in cultivar Jinshu 7. The total N uptake of Jinshu  7 was 1.35,  1.50,  1.39 times of those of Jinshu  1,  Jinshu  5,  Jinshu  8,  accordingly,  its N efficiency was 20.92%,  12.44%,  14.83% of the other three cultivars respectively. The  increase of the percentage of root N uptake and the decrease of shoot N uptake to total N uptake in Jinshu  7 was 9.75% and 3.47% respectively,  which was also smallest among the cultivars tested. Therefore,  Jinshu  7 was identified as the typical cultivar tolerant to low nitrogen stress. The results also showed a significant positive correlation between total N uptake and dry weight,  length,  total and active uptake area in roots under low nitrogen stress,  this correlation dose not exist under high nitrogen,  indicating that the morphological and physiological traits of root system plays a vary important role in N uptake under low nitrogen stress.