烟叶钾含量与烟株农艺性状和烟碱含量的相关分析

中国北方烟区土壤的普遍缺钾是影响中国烟草生产的一个重要原因。这种缺钾的土壤特性在短时间内很难得到较大的改善。利用不同基因型的烟草品种对钾素利用效率的不同选育钾高效品种是解决这一问题的一个有效途径。寻找与钾素利用效率相关的农艺性状，从农艺性状的表现选育钾素高利用效率的烟草品种能够大大加快选育的进程。此项研究对7个亲本材料的烟叶运用盐酸浸提火焰光度法测定了钾含量。对19个基因型材料调查株高、茎围、节距、单株叶数、最大叶的叶长和叶宽等农艺性状，取各基因型平均值进行与烟叶钾含量性状的相关分析。发现除了最大叶宽与烟叶钾含量呈负相关外，株高、茎围、节距、叶数和最大叶长与烟叶钾含量均呈正相关关系。其中株高、茎围与烟叶钾含量之间的相关性达到了显著，最大叶长与烟叶钾含量的相关性达到了极显著水平。以C731为材料，运用盐酸提取紫外分光光度法测定烟碱含量，发现中、上部叶随着叶龄的增大，烟碱含量逐渐增加，在叶龄的第75 d，烟碱含量达到最大值，随后呈现减少趋势；而烟叶钾含量随着叶龄的增大在不断降低。绝对钾含量由于受到干物质积累的影响，变化略有不同，但是总体上仍然是减少的。对于下部叶，烟碱含量在叶龄的第60 d增加到最大值，随后呈现减小趋势，烟叶钾含量也随着叶龄的增大在不断地减少。上、中、下三个部位的烟碱与烟叶钾含量均呈负相关关系。其中，中部叶烟碱与相对钾含量（%）和绝对钾含量（g）显著相关，并且与相对钾含量的相关程度也很高（r=-0.7126）。这说明在烟叶的全生育期内，烟叶钾含量增加时，烟碱含量是减少的。因此，提高烟叶钾含量有助于降低烟碱进而改善烟叶品质，尤其对于中、上部叶来说是很有效的。

The Relationship between Tobacco Economic Characters, Nicotine Content and Potassium Content

In northern China, the potassium content was always not enough for plant growth in soil, which was a main factor affecting tobacco production. That the potassium was not enough in soil will not be solved well in the near future. Different tobacco varieties had different potassium utilization ability, which may be one of ways to solve the problem. Looking for economic characterics related with potassium utilization, using these economic characterics to select high potassium utilization materials can shorten the selection process. The correlation analysis of some economic characterics of 19 materials and potassium content was studied. Results showed that potassium content and plant height, stem girth, step, leaf number and the biggest leaf length was positive correlation. The correlation between plant height, stem girth and the potassium content had reached significant level. The correlation between the biggest leaf length and potassium content had reached marked level. Nicotine content was also studied. Results showed that nicotine content of upper leaves and middle leaves increased with leaf age. When leaf age was 75 days, the nicotine content reached the biggest. After 75 days, the nicotine content decreased with leaf age. Potassium content of tobacco was always decreasing with leaf age. For bottom leaves, the nicotine content reached the biggest when leaf age was 60 days. After that, the nicotine content decreased with leaf age. The potassium content of the tobacco was always decreasing with leaf age. The correlation between potassium and nicotine content of leaves were negative. It suggested that nicotine content decreased with potassium content increased in the whole life of tobacco. Increasing potassium content can improve the tobacco quality.