摘要
【目的】揭示顶端调控对烤烟生长、矿质养分吸收和分配影响。【方法】采用营养液培养,结合根系养分吸收动力学方法,进行了打顶和打顶+NAA处理。【结果】对照在处理期间干物质和养分净增量最大,干物质的57%和N、P、K、Ca等养分的44%～68%分配到了顶端(包括新生叶片),而打顶和打顶+NAA植株的干物质和养分净增量的绝大部分都分配至上部叶和根系。钾离子吸收动力学结果表明,根系吸钾速率大小依次为对照>打顶+NAA>打顶,对照植株根系对钾离子的亲和力和最大吸收速率也最大。打顶+NAA处理2d后根系对钾离子的亲和力和最大吸收速率均大于打顶处理。【结论】以上结果表明,顶端不仅可以通过其生长需求(库强)调节光合产物和矿质养分在体内的分配,而且可以通过其合成的生长素调控根系的养分吸收。打顶后生长调节剂处理可一定程度上代替顶端的作用。
[Objective ] Effects of decapitation on plant growth, nutrients absorption and distributionwithin plant, as well as potassium （K） absorption dynamic and kinetics in tobacco plants were examined. [Method] A root nutrients absorption kinetic method was applied under hydroponic culture. [Result] The results showed that in the control plant, 57% of the net dry matter gain and 44%-68% of the net increase in mineral nutrients （including N, P, K, Ca, etc.） was deposited in the top. In the decapitation and decapitation＋NAA plants, the majority of the net increases in dry matter and nutrients were allocated into the upper leaves and roots. The studies on the K uptake kinetics showed that K uptake activity and affinity were the highest in the control plant, and the lowest in the decapitated plant. [Conclusion] In conclusion, the shoot apex is the strongest sink for dry matter and nutrients, and can regulate not only the dry matter and nutrients allocation among the different organs, but also the nutrients absorption activity by the auxin synthesized in and transported from the apex. Exogenous application of NAA after removal of the shoot apex can partly replace the role of the shoot apex to stimulate the root nutrients uptake activity.
出处
《中国农业科学》
CAS
CSCD
北大核心
2006年第9期1846-1852,共7页
Scientia Agricultura Sinica
基金
自然科学基金项目(NNSFCNo.30070452
No30370842)资助
关键词
烤烟
打顶
萘乙酸
钾
吸收动力学
Tobacco
Decapitation
NAA
Potassium
Uptake kinetics
