Study On Translocation Of N In Roots,Stem And Branches And Leaves And Accumulation Of N In Pods Of Yangyou No.4(B.napus L.)

Through testing the content of N and soluble protein and the amount of dry matter in different organs of Yangyou No.4 under different growing stages and different fertilizer application to study the translocation of N in roots, stem and branches and leaves and the accumulation of N in pods in rapeseed, the main results were as follows:1. The content of N and soluble protein in roots, stem and branches and leaves reached the maximum value at seeding stage, and declined gradually with the growth of plant; the content of N and soluble protein in pods of the whole plant declined from the ending of flower to the maturing. Increasing N fertilizer application could increase the content of N and soluble protein in different organs remarkably and the effect of K fertilizer application was less than that of N fertilizer application.2. The total amount of N and soluble protein in roots, stem and branches and leaves increased firstly and then decreased, usually reached the maximum value around the flowering stage generally. The total amount of N in pods of the whole plant increased gradually with the growth of pods, but the total amount of soluble protein increased firstly and then decreased, and reached the maximum value at the middle stage of seed filling. Increasing N fertilizer application could increase the total amount of N and soluble protein in different organs remarkably and delay the stage that the maximum value appeared.3. The total amount of N in pod shells increased firstly and then decreased, according with quadratic equation. Increasing N fertilizer application could increase theamount of N in pod shells remarkably and delay the stage that the maximum value appeared. The total amount of N in seeds always increased and the accumulation rate presented the slow-fast-slow, and could be expressed by Richards equation. More than 60% of N in seeds accumulated in fast increasing period. The accumulation rate of N in seeds accelerated and the accumulation period postponed with the increasing of N and K fertilizers application.4. The translocation amount of N in the roots, stem and branches and leaves increased with the increasing of N fertilizer application. But the ratio of translocation amount in their maximum values decreased with the increasing of N fertilizer application, and accounting for about 20%-30%, 30%-60% and 70%-80% respectively.5. The distribution of N in different organs changed as the growth of plant. The amount of N mainly distributed in leaves in seeding stage, in stem and branches as much as in leaves in the beginning of flower, in stem and branches in the ending of flower and in seeds in maturing.6. The N in pods coming from leaves was more than 30%, affected slightly by N fertilizer application, from stem and branches was about 30%-10%, decreased as the increasing of N fertilizer application, from roots was less than 5%, and from soil after the beginning of flower was 30%-50%, increased as the increasing of N fertilizer application.