Classification And Differential Analysis For Nitrogen Efficiency Genotypes Of Potato

Nitrogen is an important factor in potato growth and development.Screening the varieties with high nitrogen absorption and utilization characteristics has become the main way to improve the nitrogen use efficiency of potato.Altogether 26 potato varieties were treated with normal nitrogen level(CK)and low nitrogen level(1/10 of nitrogen concentration of CK)under tissue culture condition.The differences of root morphology of potato genotypes with different nitrogen efficiency were compared,furthermore,the differences of nitrogen absorption and distribution were analyzed and studied.The major findings are as follows:1.Based on biomass at different nitrogen supply levels four types of nitrogen efficiency genotypes are divided as follows,double-high types are: Zhongshu 5,Jizhangshu 12,V7,Atlantic and Qingshu 9;double-low types: Hangjinshu,Xinjia 2,Kexin 1,Huasong 7,Macken,Heijingang;low-nitrogen efficient types: Jinshu 16,Yunyin 1,Longshu 7,jizhangshu 8,and high-nitrogen are: Houqihong,Zhengfeng 6and Hongmei;2.The potato high nitrogen efficient type exihibits the longest root length,greatest root numbers and highest root-to-shoot weight ratio,while the nitrogen inefficient is the lowest.Therefore,these four indicators can be used as the screening index of potato nitrogen high-efficiency varieties.3.The nitrogen absorption efficiency and utilization efficiency of high nitrogen efficient were the highest than the other three types,which produced the greatest dry matter by using relatively less nitrogen.