The differences of nitrogen uptake and utilization in waxy corn Ⅰ.The difference genotypes in absorption and utilization of nitrogen

In order to understand the characteristic of nitrogen uptake and utilization and provide guidance for fertilization in accordance with varieties and high nitrogen utilization efficiency(NUE),31 waxy corn(Zea mays L.ceratina Kulesh)varieties released in recent years in China were selected to analyze their genotype differences of NUE under the same(nitrogen) fertilization condition.The results showed that the NUE variation of fresh ear,fresh grain and maturity grain(among) varieties were 57.82—98.65,39.43—61.31 and 31.70—53.70 kg/kg,respectively.Through cluster analysis,6 varieties of Feng nuo 2146,Jing ke nuo 267,Hu yu nuo 3,Jing ke nuo 218,Qian nuo 668 and Jing ke nuo 2000 were regarded as high yield and high NUE,no matter their harvest product being as fresh ear,fresh grain or maturity grain of the produce.In addition,their average N absorption per 100 kg fresh ear,fresh grain and maturity grain was 1.244,1.844 and 2.091 kg,respectively.Through path analysis,it was found that the total N uptake had a dominant effect on fresh ear yield and fresh grain yield,while the total N uptake and NUE had a similar effect on maturity grain yield.So the improvement of total N uptake was the crucial for improving the fresh ear and fresh grain yield of waxy corns.However,the improvement of both the total N uptake and NUE together was important for the purpose of improving the maturity grain yield of waxy corns.