施氮量及基追比对烤烟碳代谢产物及关键酶的影响

Effects of nitrogen application amount and base topdressing ratio on carbon metabolites and key enzymes in flue cured tobacco

【目的】探寻施氮量及基追比对烤烟碳代谢产物含量及关键酶活性的影响,为合理施用氮肥、提高烟叶品质和产量提供理论依据。【方法】进行不同施氮量(6,8,10 kg/667 m^(2))及基追比(5∶5,6∶4,7∶3)的两因素田间试验,以烤烟云烟87为试验材料,分别在团棵期、旺长期、现蕾期、打顶期、脚叶成熟期测定烤烟还原糖、总糖含量及碳代谢关键酶[蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)、ADPG焦磷酸化酶(AGP)、蔗糖转化酶(INV)、可溶性淀粉合成酶(SSS)、果糖-1,6二磷酸酶(FBPase)、α淀粉酶(α-amylase)]的酶活性。【结果】随着烟叶的成熟,烟叶中总糖和还原糖含量呈先下降后上升又下降的趋势;烟叶中INV、SS、α-amylase、AGP、FBPase活性呈先上升后下降的单峰曲线,SPS活性呈双峰波动的变化趋势,SSS活性呈先下降后升高再下降的趋势。随施氮量的增加,烟叶中总糖和还原糖含量呈下降趋势,SS活性整体呈不断下降的趋势,INV、SSS、FBPase活性整体呈先下降后升高的趋势,α-amylase、SPS、AGP活性整体呈先升高后下降的趋势。在施氮量相同的条件下,低氮和常规氮处理中随着追氮比例的增大,烟叶中总糖和还原糖含量整体较高,高氮处理则较低。相关分析结果表明,烟叶中的总糖含量在团棵期与SSS活性呈显著负相关。【结论】在施氮量为6 kg/667 m^(2),基追比为6∶4时,各时期碳代谢产物含量及关键酶活性较为适宜,有利于烟碳代谢相关物质积累。

【Objective】The effects of nitrogen application amount and base-dressing ratio on the content of carbon metabolites and key enzyme activities in flue-cured tobacco were investigated,so as to provide a theoretical basis for rational application of nitrogen fertilizer and improvement of tobacco leaf quality and yield.【Method】A two-factor field experiment with different nitrogen application rates(6,8,10 kg/667 m~2)and base topdressing ratio(5∶5,6∶4,7∶3)was carried out.Using flue-cured tobacco Yunyan 87 as the test material,the reducing sugar,total sugar content and activity of key enzymes,including sucrose synthase(SS),sucrose phosphate synthase(SPS),ADP glucose pyrophosphorylase(AGP),sucrose invertase(INV),soluble starch synthase(SSS),fructose 1,6-bisphosptase(FBPase)andα-amylase,were determined at resettling growth stage,the prosperous stage,the budding stage,the topping stage,and the mature stage of the foot leaf.【Result】With the mature of tobacco leaves,the contents of total sugar and reducing sugar in tobacco leaves showed a trend of first decreasing,then increasing and decreasing at last.The activity of INV,SS,α-amylase,AGP and FBPase showed as a unimodal curve of first increasing and then decrease,while the activity of SPS showed as a bimodal curve,and the activity of SSS showed a trend of first decreasing and then increasing.With the increase of nitrogen application,the content of total sugar and reducing sugar in tobacco leaves showed a downward trend.The SS activity was consistently decreasing,while the activities of INV,SSS and FBPase showed a trend of first decreasing and then increasing,and the activity ofα-amylase,SPS and AGP showed a trend of increasing first and then decreasing.With the same nitrogen application,the contents of total sugar and reducing sugar in tobacco leaves were higher as a whole.The content of total sugar and reducing sugar were higher in low nitrogen treatment,while that of total sugar and reducing sugar were lower in the high nitrogen treatment.Relative studies indicated that the SSS activity was significantly negatively correlated with total sugar at the clustering stage.【Conclusion】When the nitrogen application amount is 6 kg/667 m~2 and the base topdressing ratio is 6∶4,the content of carbon metabolites and key enzyme activities in each period are more suitable,which is conducive to the accumulation of tobacco carbon metabolism-related substances.