红壤、水稻土上不同氮素形态配比对烤烟碳氮代谢关键酶活性的影响

Effects of Different Forms of Nitrogen Fertilizer on Predominant Enzymes of C and N Metabolism in Red and Rice Soils of Flue-cured Tobacco

通过不同氮素形态配比盆栽试验,研究了K326中部叶不同发育时期氮代谢的相关酶即硝酸还原酶(NR)、谷氨酰胺合成酶(GS)和碳代谢的关键酶即转化酶(Inv)、蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)活性变化。结果表明:硝酸还原酶随硝态氮比例的增加酶活性呈上升趋势,而谷氨酰胺合成酶活性的变化趋势则与之相反;转化酶和蔗糖合成酶对烟草叶片生长发育的作用时期不同,即转化酶在烟草叶片发育中期,蔗糖合成酶在叶片发育后期。在云南玉溪砂红壤上以配施60%硝态氮复合肥有利于烟叶中碳代谢,而在水稻土上以配施40%硝态氮复合肥有利于烟叶中碳代谢。铵态氮比例过大不利于叶片碳氮代谢的适时转化。

The activity of nitric-metabolizing enzymes, such as nitrate reductase(NR),glutamine synthase(GS),and sucrose-metabolizing enzymes, such as inverse(Inv),sucrose synthase(SS),and sucrose phosphate synthase(SPS) in cutters at different growing stages of K326 were experimented in pot by applying different forms of nitrogen fertilizer. The result showed that the activity of NR was increased with NO_3^--N rates increasing, but the activity of GS was deducted; Inv and SS affected the growth of tobacco leaves at different stages,Inv at mataphase and SS at anaphase. In red soil of Yuxi tobacco growing areas,60% NO_3^--N +40%NH_4^+-N was beneficial to C metabolism, but in rice soil, 40% NO_3^--N +60%NH_4^+-N was beneficial to C metabolism. It wasn't beneficial to conversion timely of N and C metabolism when NH_4^+-N rates were raised.