Dynamic Variation of Biomass and Nitrogen Absorption Ratio of Different Genotypes in Maize under Low Nitrogen Stress

In this investigation,the biomass,nitrogen content,nitrogen accumulation and nitrogen absorption ratio(NAR)of maize at different developing stages for an elite hybrid Nongda108,its parents and its three F2:4 family lines with different nitrogen use efficiency(NUE)were analyzed under nitrogen applied and no N applied conditions by means of pot cultivation in the field.The results showed that the biomass,nitrogen content and nitrogen accumulation were higher or much higher under nitrogen applied than no N applied conditions after flowering stage,but the NAR was lower under nitrogen applied than no N applied conditions.Beside for the hybrid Nongda108 appearing obvious heterosis,the inbred line Xu178 had higher or significant higher in biomass,nitrogen accumulation and NAR in flowering and grain filling stages than the other inbred lines.The mean nitrogen content tend to be lightly decreased over stages,while the nitrogen accumulation and the NAR increased with its biomass,and highly significant relationships existed among them(R0.98),also the increasing range varied with genotypes,and the coefficient of variations after flowering stages were tree times higher than that of jointing stage,especially under no N applied conditions.Nongda108,Xu178 and L2 had higher increasing ranges,which referred that they were insensitive to low N stress.