In order to understand the characteristic of nitrogen (N) uptake and utilization and provide guidance for fertilization in accordance with varieties and high N utilization efficiency (NUE),2 potato (Solanum tuberosum L.) varieties were selected to analyze their genotype differences of NUE under the different N fertilization condition. The influence of N fertilizer application on potato dry matter accumulation,yield,NUE and quality were studied in this study using "Dongnong308"and"Yanshu4"varieties as material. The trial was made in the field in the condition of 4 N levels (0,90,180,270kg·hm-2). The main results were as follows:Dry matter weight of the whole plant was improved significant in a certain range. But the proportion of dry matter weight of tuber and the whole plant was reduced with increasing N rate. At mature period, the percentages of dry matter weight of tuber in dry matter weight of whole plant of Yanshu 4 were decreased from 75% to 68% and the percentages of Dongnong308 were decreased from 67% to 55%. Dry matter accumulation of tuber at tuber bulking stage was increased of Yanshu4, but the peak of dry matter accumulation of tuber of Dongnong308 was delayed with the increase of N application rate. N uptake and NUE of Dongnong308 and Yanshu4 were 50.73% and 54.23% respectively,and there was no significant different between them under low N rate (90kg·hm-2).But physiological NUE(142.74kg·kg-1) and N agronomic efficiency(72.41kg·kg-1) of Dongnong308 were higher than that of Yanshu4 (physiological NUE and N agronomic efficiency were 114.78 kg·kg-1 and 62.25 kg·kg-1 respectively).Physiological NUE and N agronomic efficiency of Dongnong308 decreased more evidently than that of Yanshu4 under the medium and high N application rate. In addition, the starch content and vitamin C content were reduced with in increasing of N application, but protein content was improved. From above factors,Dongnong308 belongs to the efficient-inefficient variety of and Yanshu4 belongs to the inefficient-efficient variety.%为了明确不同氮利用率类型的马铃薯氮营养特点,并为氮高效资源筛选与利用提供依据,开展了不同氮素处理下马铃薯氮吸收利用基因型差异的研究.以中晚熟品种延薯4号、东农308为试验材料,设4个氮素水平(0,90,180,270kg·hm-2)在大田条件下研究不同施氮水平对马铃薯不同品种干物质积累动态、阶段性干物质积累动态、块茎产量、氮素利用率及品质的影响.结果表明:在一定范围内增施氮肥可显著增加植株全株干物重,但会降低块茎干物重与全株干物重的比例.成熟期随着施氮量的增加,延薯4号块茎干重占全株干重比例由75%下降到68%,东农308由67%下降到55%.增施氮肥促进延薯4号块茎膨大期的块茎干物质阶段性积累,而东农308块茎阶段干物质积累高峰期向后推迟.低氮(90kg·hm-2)条件下,东农308与延薯4号氮素吸收利用率分别为50.73%和54.23%,水平相近;而东农308氮素生理利用率(142.74kg·kg-1)、农学利用率(72.41kg·kg-1)均高于延薯4号(生理利用率和农学利用率分别为114.78kg·kg-1和62.25kg·kg-1).但在中氮和高氮(270kg·hm-2)条件下,东农308与延薯4号相比生理利用率、农学利用率下降迅速.2个品种淀粉含量、维生素C含量均随施氮量的增加呈下降趋势,粗蛋白含量随着施氮量的增加呈增加趋势.根据产量水平与品质的综合比较,东农308属于低氮高效型品种,而延薯4号属于高氮高效型品种.
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