The effects of topping and NAA application on potassium absorption, accumulation, as well as the re-distribution of flue-cured tobacco were studied in order to provide theoretical references for regulating nutrition and quality of flue-cured tobacco. [Method ]This study was carried out at different stages of tobacco developments along side with pot experiments and different treatments (topping, apex-keeping, and NAA) on tobacco plants. [Result]The results showed that topping accelerated dry matter accumulation of tobacco leaf, stem, and root, increased the potassium content in root as well as the middle leaves and stem at earlier stage of tobacco, but decreased that of upper leaves, middle leaves, and stem at later stage. It could also promote the potassium accumulation in leaves, stem, root, and its distribution in leaves. The bioavailability rate of potassium decreased, but the economic utilization rate of potassium in tobacco plants increased. After topping, the application of exogenous NAA could significantly increase the accumulation of potassium in tobacco plants, potassium content in- middle leaves at earlier stage, and the contents in roots at later stage, while decrease potassium content in the upper leaves and stem; furthermore, the application of exogenous NAA could increase potassium accumulation in leaf, stem, and root, promote potassium distribution in tobacco leaves, and increase the economic utilization and bioavailability rates of potassium in tobacco plant. [ Conclusion ]The application of exogenous NAA after topping could balance different endogenous hormones, increase potassium accumulation in tobacco leaves, promote the absorption and redistribution of potassium, and improve the leaf quality.q%[目的]研究打顶及外源α-萘乙酸(NAA)对烟叶钾素吸收、积累及再分配的影响,为烤烟营养和品质调控提供参考.[方法]采用盆栽试验,设置打顶、留顶和NAA处理,在不同时期探讨其对烟株钾素的吸收和积累、再分配的影响.[结果]打顶加速烟叶、茎秆和根系干物质的积累,提高根系及前期中部叶和茎秆的钾含量,降低上部叶及后期中部叶和茎秆钾含量;利于促进钾素在烟叶、茎秆和根系中的积累;促进钾素向烟叶分配;降低烟株钾素生物利用率,提高烟株钾素经济利用率.打顶期施用外源NAA可明显提高烟株干物质的积累量,提高前期中部叶和后期根系的钾含量,但降低上部叶、茎秆的钾含量;提高烟叶、茎秆和根系中钾的积累量,促进钾素在烟叶中的分配,提高烟株钾素生物利用率和经济利用率.[结论]打顶期施用外源NAA有助于保持烟株内源激素的平衡,增加烟叶钾积累,促进钾素的吸收与再分配,改善烟叶品质.
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