Abstract:

In order to explore the effects of auxin and molybdenum on the physiological metabolism and quality of flue-cured tobacco， a field experiment was conducted to measure the photosynthesis， carbon and nitrogen metabolism， physical properties and chemical composition by using the cultivar‘Yunyan 87’as material. The results showed that compared with the control， the application of auxin and molybdenum after topping increased the contents of photosynthetic pigments （chlorophyll， carotenoids）， the values of gas exchange parameters （net photosynthetic rate， stomatal conductance， transpiration rate） and the enzymes activities of carbon and nitrogen metabolizing （amylase， invertase， nitrate reductase， glutamine synthetase）； the leaf length， leaf width， single leaf weight， filling value， tensile strength， potassium， total sugar and reducing sugar contents increased significantly， while the contents of nitrogen and nicotine decreased significantly. The total variation contribution rates of auxin and molybdenum to photosynthetic pigments of tobacco leaves were 68.85%， 13.23%， respectively； to the gas exchange parameters were 50.66% and 42.63%， respectively； to the rates of carbon and nitrogen metabolizing enzymes were 40.74%， 34.02%， respectively； to the rates of physical properties were 46.72%， 49.55%， respectively； to the rates of chemical composition were 54.94%， 36.22%， respectively. On the whole， auxin was the main effector molecule， the treatment of spraying 20 mg·kg^-1 auxin and 4 mg·plant^-1 molybdenum had the best effect on tobacco for promoting physiological metabolism and improving quality.The above results provided a theoretical basis for the rational application of hormones and trace elements in flue-cured tobacco production.

Key words: auxin, molybdenum, flue-cured tobacco, carbon and nitrogen metabolism, quality

摘要：

为探究生长素与钼配施对烤烟生理代谢及品质的影响，以‘云烟87’为材料，通过田间试验研究生长素和钼肥对烤烟光合作用、碳氮代谢、物理特性和化学成分的影响。结果表明，与对照相比，打顶后喷施生长素并追施钼肥不同程度地提高了叶片光合色素（叶绿素、类胡萝卜素）含量、气体交换参数（净光合速率、气孔导度、蒸腾速率）值和碳氮代谢酶（淀粉酶、转化酶、硝酸还原酶、谷氨酰胺合成酶）活性；提高了烤后烟叶的叶长、叶宽、单叶重、填充值和抗张力，烟叶钾、总糖、还原糖含量显著增加，总氮、烟碱含量显著降低。生长素和钼肥对烤烟光合色素总变异的贡献率分别为68.85%、13.23%，对气体交换参数总变异的贡献率分别为50.66%、42.63%，对碳氮代谢酶总变异的贡献率分别为40.74%、34.02%，对物理特性总变异的贡献率分别为46.72%、49.55%，对化学成分总变异的贡献率分别为54.94%、36.22%。总的来看，生长素为主要效应因子，喷施生长素20 mg·kg^-1并追施钼肥4 mg·株^-1的处理在促进生理代谢和提高烟叶品质方面效果最佳。以上研究结果为激素和微量元素在烤烟生产中的合理应用提供了理论基础。

关键词: 生长素, 钼, 烤烟, 碳氮代谢, 品质