【摘要】 采用 8 6 Rb标记示踪原子法研究烤烟使用生长素后 ,烟株中钾素再循环再分配的情况。研究发现 ,涂抹生长素处理后能增加 86 Rb在木质部中的运输量 ,并能有效地降低 86 Rb经韧皮部下运的量 ,更有利于钾在烟叶中的积累。生长素处理后叶片中 86 Rb的分配比例提高 ,而茎和根的分配比例降低。打顶使 86 Rb在茎和根中的分配比例上升 ,叶片中的分配比例下降。外源生长素在钾充分情况下 ,更有利于烟叶对钾的吸收。留顶 (内源生长素未受到破坏 )在缺钾情况下 ,对烟株叶片钾积累有一定的调节功能 ,但在高钾情况下存在根茎顶等非经济部位对钾的奢侈吸收。在同等钾水平下 ,外源生长素对烟株铷吸收率的作用大于内源生长素。打顶或留顶均会影响烟株对铷的吸收。打顶并使用生长素 ,可有效地抑制烟株对铷吸收率下降的趋势。打顶若钾供应充足 ,烟株仍然可从土壤中吸收一定的钾素。烟株整株钾的积累量在下、中、上部叶片的三个成熟期都是生长素处理高于留顶处理 ,留顶处理高于打顶处理。烟株叶片钾的积累量趋势也如此。更多还原

【Abstract】 The potassium distribution and accumulation in the various organs of tobacco were investigated using 86 Rb (substitution of 86 RbCl for 40 K ). The transportation amount of 86 Rb increased in xylem and decreased effectively in phloem, and the proportion of 86 Rb increased in leaves but dropped in stem and roots, when the auxin was applied to the tobacco plant. On the other hand, top cutting had a contrary effect, i.e, the proportion of 86 Rb increase in stem and root and dropped in leaves. The exogenous auxin was advantagenous to the K accumulation in leaves and inhibited probably the decline in K content of leaves if top cutting practiced. The K accumulative amount in whole tobacco plant was the highest in the auxin applied, followed in top leaving over and in top cutting. The similar tendency also existed in tobacco leaves.更多还原