Variation Of Nitrogen Uptake And Utilization Efficiency In Potato Genotypes

One of the main reason for potato yield increase is attributed to the nitrogen input.However,excessive application of nitrogen fertilizer not only increases investment cost,reduces economic benefits and nitrogen use efficiency,but also causes many environmental problems.Screening the varieties with high nitrogen efficiency is an important way to solve these problems.The nitrogen efficiency is largely dependent on the nutrient uptake and utilization of plants.Based on this,seven potato cultivars were used as experimental material to evaluate the genetic variation on nitrogen efficiency.The differences of physiological mechanism in nitrogen uptake and utilization efficiency of potato plants was investigated in this study,aimed to provide a theoretical basis for high nitrogen efficiency breeding and rational application of nitrogen fertilizer.The main results are as follows:1.Taking the yield of different nitrogen fertilizer rates as the main evaluation index of nitrogen efficiency,the potato was divided into 4 types: double high(high nitrogen efficiency),double low type(low nitrogen efficiency),low nitrogen and high efficiency type and high nitrogen and high efficiency type.2.The morphological characteristics of root system is closely related to the nitrogen uptake efficiency of potato plants.The higher root dry matter accumulation,root volume,total root length and root surface area are the main reasons for the high nitrogen absorption efficiency.3.The nitrogen use efficiency of different potato genotypes is closely related to the accumulation of dry matter.The higher leaf area index,SPAD value and net photosynthetic rate cause high efficiency of nitrogen utilization.