不同外源物质（灌根）对烤烟根系及烟叶养分吸收的影响

　　摘要：【目的】明確外源物质根系调控促进烤烟养分吸收和利用的作用机制，为进一步完善基于烤烟提质增效的外源根系调控技术提供科学依据。【方法】采用盆栽试验，设常规施肥（T1）和在常规施肥基础上添加苹果酸（T2）、生根粉（T3）、复硝酚钠与海藻酸钠混合剂（T4）、解淀粉芽孢杆菌FZB42（T5）和膨胀素（T6）6个灌根处理，同时设植烟不施肥处理（CK）用于计算肥料利用率。于团棵期、现蕾期、采收结束时分别测定烟株根、茎、叶干重及烟叶的氮、磷、钾含量，同时测定土壤速效氮、速效磷和速效钾含量。【结果】相对于T1和CK处理，T4、T5和T6处理显著提高了烤烟各生长阶段根系生长速率（P<0.05，下同），增加了根系和地上部干物质积累量，提高了烟叶对氮、磷、钾营养元素的吸收量，而各处理烟叶占地上部干物质积累的比例随着生育进程推进逐渐减小。回归分析结果显示，烤烟团棵至现蕾阶段根系干物质积累量与烟叶氮（R2=0.87）、磷（R2=0.94）、钾（R2=0.88）元素的吸收量均呈极显著正相关（P<0.01），此阶段根系生长速率的显著提高是外源物质促进烤烟叶片养分吸收和利用的关键。T4和T5处理提高团棵至现蕾阶段根系生长速率50%以上，显著增加了烟株的干物质积累量，烟叶氮素吸收量分别增加46%和66%，磷素吸收量分别增加77%和118%，钾素吸收量分别增加58%和69%。【结论】基于烤烟根系促生效果的稳定性和应用安全性，解淀粉芽孢杆菌FZB42灌根可作为玉溪红壤烟区烤烟根系调控的主要手段。
　　关键词： 烤烟；根系调控；外源活性物质；养分吸收；肥料利用率
　　中图分类号： S572.01 文献标志码：A 文章编号：2095-1191（2017）05-0812-08
　　Root growth and nutrients uptake of tobacco leaf in response to different exogenous substances（root-irrigation）
　　BU Ling-duo， LI Jiang-zhou， ZHANG Li-meng*， JI Si-gui， CUI Yong-he， JIAO Yong-ge
　　（Yuxi Branch， Yunnan Tobacco Company， Yuxi， Yunnan 653100， China）
　　Abstract：【Objective】The purpose of this paper was to illuminate the mechanism of exogenous substances on promoting nutrients uptake and utilization of tobacco， and provide reference for improving the exogenous root control technology based on quality and efficiency improvement for tobacco. 【Method】Pot experiments were conducted. Conventional fertilizer（T1）， and adding malic acid（T2）， rooting powder（T3）， sodium nitrophenolate and sodium alginate mixture（T4）， Bacillus amyloliquefaciens FZB42（T5） and expansin（T6） based on conventional fertilizer were set. No fertilization treatment for tobaccos was set as control（CK） to calculate fertilizer utilization rate. Dry matter of root， stem and leaf， as well as contents of nitrogen， phosphorus and potassium in leaf were measured at tobacco resettling， budding， and harvest over periods. Meanwhile， available nitrogen， available phosphorus and available potassium contents in soil were detected. 【Result】Compared with CK and T1， root growth rate was significantly（P<0.05， the same below） increased in T4， T5， and T6 during each growth period， dry matter accumulation of both root and ground plant， and nutrients（nitrogen， phosphorus and potassium） uptake were also increased. However， the proportion of tobacco leaf in total ground dry matter accumulation was decreased as growth periods advanced. Regression analysis showed that， root dry matter accumulation was significantly positively related to nitrogen（R2=0.87）， phosphorus（R2=0.94）， and potassium（R2=0.88） uptake from resettling to budding period（P<0.01）. At this period， significant increasement of root growth rate was the key in exogenous substances promoting leaf nutrients uptake and utilization. T4 and T5 increased root growth rate by over 50% from resettling to budding period and significantly improved dry matter accumulation of tobacco. Leaf nitrogen uptake was increased by 46% and 66%， phosphorus uptake was increased by 77% and 118% and potassium uptake was increased by 58% and 69% respectively in T4 and T5. 【Conclusion】Considering stable effect and application security of tobacco root promoting， B. amyloliquefaciens FZB42 root-irrigation can be applied as a major regulation measure in Yuxi red-soil tobacco planting area.

相关热词搜索：烤烟 根系 烟叶 养分 吸收