中文摘要：

以烤烟（Nicotiana tabacum L.K 326）为试验材料.在大田条件下,利用^15N示踪法,研究了土壤氮对烤烟氮素累积和烟碱合成的影响。结果表明。对烤烟氮素累积和烟碱合成的影响。土壤氮比例均随叶位上升而上升,且打顶后上、中、下三个叶位和根茎中土壤氮比例均随生育时期推进而显著增加;打顶后烤烟各器官的土壤氮占总氮比例和占总烟碱氮比例分别为50%和60%。显著高于肥料氮。

英文摘要：

In this work, flue-cured tobacco cuhivar （Nicotiana tabacum L. K 326） was used to study the effect of soil- N on nitrogen and nicotine accumulation in flue-cured tobacco using the N^15-trace method in a field experiment. The resuits indicated that soil-N proportion to total N and that in nicotine in leaves increased with the increased leaf position （down to up）. Also soil-N proportion to total N in different organs of tobacco plants increased with the prolonged growth duration, especially after removing of the shoot apex. Soil-N in all organs of plants after removing of the apex accounted for 50 % and 60 % of total N and