用^（15）N－尿素研究油菜角果成熟期荚中氮的运转

Studies on Translocation of N in Pods of Oilseed Rape During Siliqua Developing Using ￣(15)N-urea￣①

盆栽条件下，用^（１５）Ｎ－尿素测定了油菜角果成熟期荚中氮的运转。于开花后三个不同时期，将^（１５）Ｎ－尿素涂布于油菜主轴基部荚的表面，植株成熟后测定不同部位荚的荚壳和籽粒的含Ｎ量和^（１５）Ｎ丰度，计算施用Ｎ的回收率，荚中为７９．１％－８４．３％，其中标记荚为７５．３％－８０．４％。开花后４周施用的Ｎ从标记荚的回收率低于开花后２周和６周施用Ｎ的回收率。吸收的尿素Ｎ大部分运转至籽粒，其分配比例随施用时期的推迟而增加。

A pot experiment was conducted to investigate the translocation of N in pods during siliqua developing of oilseed rape using ￣(15)N-urea. The ￣(15)N was applied on surface of basal pods at the rachis in three periods after flowering. The hulls and seeds of pods at different parts of plants at maturity were subjected to analyse N content and ￣(15)N abundance,and recoveries of N applied were calculated. 79.1%-84.3% of N applied were recoveried from pods including 75.3%-80.4% in labelled pods, The recoveries of N from pods labelled at 4 weeks after flowering was lower than that at 2 and 6 weeks after flowering. A great majority of applied N was translocated into seeds,the later the N applied,the greater the proportion of N in seeds was.