打顶后NAA处理对烟草生长烟叶中钾和烟碱浓度的影响

Effects of NAA Application after Removing the Shoot Apex on Growth,K+ and Nicotine Concentrations in Component Tissues of Flue-cured Tobacco Plants

在云南省田间连续三年研究了打顶后在茎断面涂抹萘乙酸(NAA)处理对烤烟植株生长、钾素吸收、烟叶中钾和烟碱浓度的影响。结果表明,打顶导致烟株中的钾素损失,烟叶中钾浓度下降,烟碱浓度增加。打顶后在茎断面用NAA处理可以增加烟株对钾素的吸收,促进钾素向叶片中分配,使叶片钾浓度提高;同时降低叶片烟碱浓度。第一次NAA处理两周后用NAA再处理一次虽然可以进一步提高烟叶钾浓度,但使叶片干重稍有下降,且在操作上多一道工序。若开花后不打顶,虽然叶片中钾浓度较高,但大大降低了叶片干物重,严重影响叶片的产量和品质。

Field experiments were conducted in three years（1999,2000 and 2001）in Yunnan province to study the effects of NAA application after removing the shoot apex on plant growth,K＋and nicotine concentrations in different organs of flue-cured tobacco.The results showed that,excision of the shoot apex caused a net decrease in total K＋content of whole plant,a decrease in K＋concentration while an increase in nicotine concentration in different leaves.Application of NAA onto the cut-surface of the stem after removal of the shoot apex stimulated K＋ uptake and distribution into the leaves,resulted in increase in K＋concentration and decrease in nicotine concentration in different leaves.Applying NAA twice（once again two weeks after the first application）could further improve leaf K＋concentration,but cause a slight decrease in leaf dry weights.Keeping plant intact（no removing the shoot apex）resulted lower leaf dry weights and yield,and poor leaf quality,compared with the apex-removed plants,although the leaf K＋concentration was higher in the intact plants.NAA application one time after removal of the shoot apex was enough for increasing in K＋ concentration and decreasing in nicotine concentration in tobacco leaves.