不同供钾水平下烤烟体内钾的循环、累积和分配
Circulation, accumulation and distribution of potassium in flue-cured tobacco with different potassium levels
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摘要: 在营养液培养条件下 ,利用Jeschke等人建立的模型 ,定量研究了不同供钾水平下烤烟体内钾的循环、累积和分配。结果表明 ,供钾水平对烤烟干物重影响不显著 ;供钾水平提高能显著提高烤烟叶片以及根和茎的含钾量 ,增加烤烟体内钾素累积。不同供钾水平下的烤烟 ,在打顶后 10天内 ,体内都有大量钾离子沿韧皮部由地上部回流到根中 ,回流到根中的钾量占由根运输到地上部的钾量的比例大约在 50 %以上。供钾水平低时 ,该比例明显降低 ,供钾水平提高 ,钾循环量增加。不同供钾水平下 ,烤烟体内钾分配比例都是叶片最高 ,根和茎较低 ;打顶后 10天内烤烟叶片中钾分配减少 ,根中钾分配增加Abstract: The solution culture experiment was carried out to study the effect of potassium supply levels on circulation, accumulation and distribution of potassium in flue-cured tobacco. The results showed that there were large amounts of potassium flowing from shoot back to root in flue-cured tobacco. The flowing amount of potassium in phloem was more than about 50% of the amount in xylem. The potassium circling amount between root and shoot increased as potassium supply levels increased. The difference of dry weight of flue-cured tobacco among potassium supply levels was not significant. The potassium contents of leaf, stem and root of flue-cured tobacco increased significantly as the potassium supply levels increased. The leaf potassium content could be quite high if there were large amounts of potassium ion supplied. The highest K2O content of leaf in this experiment was 8.8%. The potassium distribution proportion in organs of flue-cured tobacco was highest in leaf, lower in stem and root under different potassium supply levels. After topping, potassium distribution proportion decreased in leaf and increased in root.