顶端调控措施对烤烟生长、内源激素及氮钾累积的影响

【研究目的】该文探讨了打顶初期2周内打顶和植物生长调节剂对烤烟生长、内源激素和氮钾累积的影响。【方法】在盆栽基质培养条件下，进行了打顶和打顶+生长调节剂处理，采用酶联吸附免疫测定技术分析了烤烟根和叶中内源IAA、ABA、GA3和ZR的变化。【结果】与不打顶相比，打顶能够降低烤烟叶内IAA、ABA、GA₃和ZR的含量，刺激根中IAA、ABA、GA₃和ZR的增加，其中1h时打顶叶中IAA含量比不打顶降低了2倍，14d时打顶根中IAA含量比不打顶和打顶生长调节剂处理增加了140.70%和110.77%，5h和24h时打顶根中GA₃含量比不打顶增加124.18%和106.66%。打顶和打顶＋生长调节剂处理干物质和氮素累积与不打顶相比主要在中上部叶、茎和根，钾累积量在叶和根中，茎和整株钾累积量降低。【结论】顶端的存在影响内源激素、光合作用产物和养分在烟株体内的累积，打顶后涂抹植物生长调节剂在一定程度上代替烟株顶端的作用。

Shoot Apex Regulates Growth, Endogenous Hormone and Potassium and Nitrogen Accumulation in Flue-cured Tobacco

【OBJECTIVE】Effects of decapitation and plant growth regulator on plant growth, endogenous hormones and N, K accumulation were examined within 2 weeks.【METHOD】The method of enzyme-linked immunosorbant assay (ELISA) was employed to determine the contents of indoleacetic acid (IAA), abscisic acid (ABA), gibberellin (GA3) and Zeatin(ZR) under pot culture. 【RESULTS】The results showed that the content of endogenous hormone IAA, ABA, GA3 and ZR decreased in leaves and increased in roots of decapitated plants compared to no decapitated plants. The content of IAA in leaves of decapitated plants was 2-fold lower than that of no decapitated plants at 1h, and it represented a 140.70% and 110.77% rise in roots compared to that of no decapitated and IAA-treated plants at 14d. The GA3 content in roots of decapitated plant was 124.18% and 106.66% higher than that of no decapitated plants at 5h and 24h, respectively. In decapitated and IAA-treated plants, the net increases in dry matter and nitrogen accumulation were allocated into the middle and upper leaves, stems and roots, and potassium accumulation increased in middle, upper leaves and roots, but the potassium accumulation in whole plant and stems were lower than that of no decapitated plants.【CONCLUSION】The shoot apex can regulate the accumulation of dry matter, endogenous hormone, potassium and nitrogen among different organs of tobacco. Applications of plant exogenous growth regulator after removel of the shoot apex can partly replace the role of the shoot apex.