烤烟δ^(13)C值及生理特征对不同施氮水平的响应

δ^(13)C Values and Physical Characters of Flue-Cured Tobacco Leaves in Response to Different Nitrogen Levels

探索自然条件下‘云烟87’的最佳施氮量,为‘云烟87’的大田种植提供一定的参考。选择自然条件下种植的‘云烟87’烤烟品种为试验材料,设置每公顷施纯氮60、82、105 kg 3个不同供氮水平进行对比试验,分别记为处理1、处理2和处理3。于打顶前后分4次对7、10、13和15叶位取3株同叶位鲜烟叶,分别测定其稳定碳同位素(δ13C值)、比叶重、光合色素、总碳、全氮、碳氮比等。结果表明:同一气候条件不同施氮处理种植环境下,处理3的色素含量及全氮含量最高,C/N比值及比叶重最低;处理2比叶重、δ13C值以及总碳含量最高,全氮含量以及C/N比值略低于处理3;处理1δ13C值以及碳氮代谢等方面的表现均较差。研究以烟叶稳定碳同位素(δ13C值)为主线,辅以烟叶比叶重、光合色素和碳氮代谢等指标的综合评估,认为‘云烟87’在82 kg/hm2的施氮水平下表现较佳,105 kg/hm2的施氮水平下的烟株表现居中,而60 kg/hm2的施氮水平的烟株则表现最差。据此,可判定‘云烟87’更适宜在每公顷施纯氮82 kg的施肥水平下种植。

The purpose of this study is to find the optimum amount of nitrogen of‘Yunyan 87＇in naturalcondition, which could provide a certain reference for the field planting of‘Yunyan 87＇.‘Yunyan 87＇tobaccogrown under natural condition was selected as the test material, the authors set 3 different nitrogen levels, 60,82 and 105 kg/hm2 for contrast test, namely treatment 1, treatment 2 and treatment 3. Three fresh leaves on the7 th, 10 th, 13 th and 15 th leaf position were taken before and after topping, and stable carbon isotope（δ13C value）, specific leaf weight, total nitrogen, C/N ratio and so on were determined. The results show that：under the same climatic condition and with different nitrogen treatments, photosynthetic pigments and the totalnitrogen of treatment 3 are the highest, and C/N ratio and specific leaf weigh are the lowest; specific leafweight, δ13C value and the total carbon of treatment 2 are the highest, and the total nitrogen and C/N ratio areslightly lower than that of treatment 3; δ13C value, carbon and nitrogen metabolism and other aspects ofperformance are poor. In conclusion, the performance of‘Yunyan 87＇tobacco with 82 kg/hm2 nitrogen is thebest, followed by that with 105 kg/hm2 nitrogen, while the performance of‘Yunyan 87＇tobacco with 60 kg/hm2 nitrogen is poor. Accordingly,‘Yunyan87＇is more suitable for planting with 82 kg/hm2 nitrogen.