Effects of N on dry matter and N accumulation of detached wheat spikes in vitro culture.

Taking Zhoumai 18 as experiment material,the effects of N on dry matter and N accumulation of detached wheat spikes in vitro culture were studied under different levels of N application(0,0.5,1 and 2g/L NH4NO3,respectively).The spikes were collected 7 days after anthesis.The results showed that the dry matter accumulation of detached spikes increased with the increase of culture time.Exogenous N promoted the dry matter accumulation and improved the distribution rate in grains in detached spikes.The supply of exogenous N decreased the translocation efficiency of dry matters from vegetative organs and their contribution rate to grain,but the photosynthetic product in grains increased.Exogenous N also improved the N accumulation in detached spikes,increased the N content and accumulation in grains,and promoted the N distribution rate in grains.In the study,the best treatment was 2.0g/L NH4NO3.