[Objectives] High Cl-content in soil is one of the main factors for high Cl-content in tobacco leaves,which plagues tobacco production in some tobacco-growing area of China.Studying the effect of Cl channel inhibitors on the physiological and biological indexes of flue-cured tobacco would provide reference for approaching reasonable way of relieving the adverse impaction in tobacco production.[Methods] Three Cl-inhibitors,Zn2+,NFA and 9-AC,were tested in a pot experiment,in which the used soil Cl-content was 50 mg/kg.All the three Cl-inhibitors were made into water solution of 200 μmol/L,each time irrigated 1 L per pot and consecutively for 3 days after the tobacco plants were transplanted for 30,45,60 and 75 days.The expression of CLC-Nt2 gene,photosynthetic pigments content,chlorophyll fluorescence parameters,the related elements accumulation and plant biomass were measured in maturing leaves.[Results] 1) There was no significant difference in the expressions of CLC-Nt2 gene in tobacco leaves among the Zn2+,NFA and 9-AC treatments,but they were all significantly lower than those in control,which were 82.22％,75.39％ and 72.19％ respectively.2)Inhibitor treatments could obviously raise the content of chlorophyll,with the increasing rate of 20.15％ (Zn2+),29.10％ (NFA) and 45.52％ (9-AC) separately compared with CK.The chlorophyll fluorescence in each treatment was higher than the control to a certain degree,which had remarkable benefit to decrease the damage of the PS Ⅱ photosynthetic apparatus in tobacco leaves.3) Compared with control,the leaf Cl-contents were significantly decreased by 18.17％～33.48％,while the K+ and NO3 were apparently increased by 5.28％-10.20％ and 12.19％-25.24％,with the best effect in 9-AC.4) Tobacco biomass were significantly affected by the use of inhibitors.Compared with CK,the dry weight of leaf,stem and the total biomass were significantly promoted and increased by 17.02％-32.45％,10.54％-20.66％ and 13.21％-25.50％,while the root dry weight increased only by 5.94％-11.43％.Therefore,the root-shoot ratio was comparatively lower.The biomass was showed in the order of 9-AC ＞ NFA ＞ Zn2+ ＞ CK.[Conclusions] Irrigation of chloride channel inhibitors can alleviate chloride damage to tobacco plants planted in soil with relatively higher Cl-content,because of the positive reactions to growth and physiological activities of flue-cured tobacco.200 μmol/L 9-AC shows the best performance in the experimental condition,200 μmol/L Zn2+ could meet the needs of reduction of chlorine ion in tobacco leaves with low cost in practice.%[目的]在我国部分烟区,土壤氯离子含量高是造成烟叶氯离子含量高的一个主要因素,困扰着当地优质烟草的生产.研究氯离子通道抑制剂对烤烟成熟期叶片生理指标的影响,可为生产中合理降氯提供一定的参考. [方法]2015年在河南科技大学采用盆栽土培试验,设置四个处理,分别为200 μmol/L NFA、200 μmol/L9-AC、200μmol/L Zn2+和蒸馏水,土壤含氯量为50 mg/kg.于移栽后30、45、60、75 d灌根,每个处理每次每盆灌1L,连灌3天.测定了成熟期烤烟中部功能叶片中的CL C-Nt2基因表达强度、光合色素含量、叶绿素荧光参数、相关元素积累量以及烟株生物量. [结果]1)与对照相比,施用抑制剂Zn2+、NFA、9-AC的烟株叶片中CL C-Nt2的表达量显著降低,分别为对照的82.22％、75.39％、72.19％,但3组抑制剂处理之间无显著差异.2)Zn2+、NFA、9-AC处理的叶片叶绿素总含量较对照分别增加20.15％、29.10％、45.52％,差异达到显著水平.同时,经不同抑制剂处理的叶片叶绿素荧光特性也表现出不同程度的增加,表明抑制剂可以减缓氯含量对烤烟PSⅡ光合机构的伤害.3)抑制剂对烤烟叶片中C1、K+、NO3的积累有明显影响.与对照相比,抑制剂处理的3组叶片中C1含量显著降低,降幅在18.17％～33.48％;K+含量和NO3-含量明显提高,增幅分别为5.28％～10.20％和12.19％～25.24％,其中以9-AC处理的效果最佳.4)抑制剂对烤烟生物量的合成有促进作用.与对照相比,施用抑制剂后烟株叶、茎、总干重显著提高,增幅分别为17.02％～32.45％、10.54％～20.66％和13.21％～25.50％;而根干重增加幅度较小,仅为5.94％～11.43％,根冠比显著降低.抑制剂的作用效果表现为9-AC＞ NFA＞ Zn2+＞ CK. [结论]当植烟土壤中氯离子含量较高时,外施氯离子通道抑制剂能够对烤烟植株生长及体内一系列生理活动产生积极作用,在一定程度上缓解了氯害对烟草的不利影响.在本试验条件下,施用200 μmol/L 9-AC的烟株整体表现最优,而施用200 μmol/L Zn2+的处理在基本满足降低叶片氯离子含量的同时降低了生产成本,这为生产中合理降氯提供了一定的参考.
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