不同品种油菜氮效率差异及其成因分析

采用盆栽试验，以氮胁迫与正常供氮条件下籽粒产量的比值作为氮效率系数，探讨了不同品种油菜氮效率差异及其生理基础。结果表明，所测定的8个油菜品种氮效率系数的变化范围是0．37～0．69；氮胁迫与正常供氮条件下不同油菜品种植株氮素累积吸收量、生长后期茎叶氮素转运率及氮素生理效率的比值不同，氮效率高的品种，其比值高，反之亦然;在氮素供应水平低的情况下，氮效率高的品种具有较长的根长、较多的侧根、较高的茎叶硝态氮再利用量和叶片硝酸还原酶活性。

Studies on Nitrogen Efficiency Differences and Its Reason Analysis in Different Oilseed Rape Cultivars

Differences of N efficiency of oilseed rape(Brassica napus L.)varieties and their physiological properties were studied using a pot experiment and the ratio of seed yield with stressed nitrogen to that with normal N supply was adopted as nitrogen efficiency coefficient.Results showed that the determined nitrogen efficiency coefficient of 8 oilseed rape varieties varied from 0.37 to 0.69,the ratio of nitrogen uptake amounts per plant,nitrogen transfer velocity from stems and leaves to seeds,and nitrogen physiological efficiency of oilseed rape varieties under N stressed condition to that with normal N supply were different.The higher the nitrogen efficiency,the higher their ratio.Under low nitrogen-supplying condition,high nitrogen efficiency varieties had longer roots,more lateral roots,higher nitrate reuse amounts of stem and leaves and nitrate reductase activities in leaves.