中文摘要：

采用砂培试验,在两种施氮水平下研究3个油菜品种根系形态特征与生理特性差异及其与氮效率系数的关系。结果表明：在正常供氮条件下,3个油菜品种的根系干重、一级侧根数以及总根长差异明显,根系活力、根系总吸收面积和活跃吸收面积品种间差异不显著;在氮胁迫条件下,根系干重、一级侧根数、总根长以及根系活力差异明显,根系总吸收面积和活跃吸收面积品种间差异不显著。在正常供氮和氮胁迫条件下以上各项指标比值的变化趋势是：氮效率系数高的品种,其比值高,反之亦然,尤其是根系干重和一级侧根数的变化趋势与氮效率系数完全一致。

英文摘要：

Using sand cultural experiment, the differences of morphological characters and physiological characteristic of roots among 3 oilseed rape cultivars, the relationship between characters and nitrogen use efficiency under two nitrogen supply levels were studied. The results showed that under normal supply nitrogen, the differences of the dry weight, the first lateral root and the total length of roots of 3 oilseed rape cultivars were obvious, while the differences of the vigor, the total absorbing area and active absorbing area of roots were not significant. Under nitrogen stress condition, the DW, first - class lateral, total length and vigor of roots were obvious, but the differences of the total absorbing area and the active absorbing area of roots were not significant. The change trend of the proportion of indexes under normal and stress of nitrogen was that the cuhivars of high coefficient of NUE had high proportion, and vice versa, particularly the change trend of the DW and first - class lateral of roots was consistent with the change trend of the coefficient of NUE.