外源GA_3和IAA对陕南烤烟上部叶品质的影响

Effects of Exogenous GA_3 and IAA on Quality of Upper Leaves of Flue-Cured Tobacco in Southern Shaanxi Province

在陕南烟区采用田间试验,以云烟99为材料,通过两因素交互试验,研究了外源喷施不同浓度的GA_3(Gibberellin)和IAA(Indole-3-acetic acid)对烤烟上部叶全碳、可溶性总糖、还原糖、淀粉、全氮、烟碱、全钾含量、经济性状以及烤后化学成分的影响,目的在于寻求改善陕南烟区上部烟叶品质,提高其可用性的有效途径。结果表明,与对照相比,喷施外源GA_3 50mg/L+IAA 30mg/L能够显著增加打顶后30d烤烟上部叶的全碳、全钾、可溶性总糖和还原糖含量,其增幅分别为23.80%、46.58%、38.10%和48.55%;同时,提高了烤后烟叶的糖碱比、氮碱比,降低了烟碱和淀粉含量,且二者协同效果好于单施,尤其对产量、上等烟比例、烤后可溶性总糖含量、还原糖含量有显著的促进作用。综合分析,GA_3 50mg/L+IAA 30mg/L二元协同施用可作为提升上部烟叶品质的技术措施,对改善上部烟叶品质具有较好参考价值。

To explore an efficient way for improving the quality of upper leaves of flue-cured tobacco in Southern Shaanxi province, a field experiment was conducted to study the effects of gibberellin （GA3） and indole-3-acetic acid （IAA） on contents of total carbon, soluble total sugar, reducing sugar, starch, total nitrogen and nicotine, the economic characters and chemical compositions in upper leaves of flue-cured tobacco using Yunyan 99 as material. There were significant increases in the contents of total carbon, total potassium, total soluble sugar and reducing sugar by 23.80%, 46.58%, 38.10% and 48.55%, respectively, under the combination treatment of GA3 50mg/L and IAA 30mg/L at 30 days after toping. Moreover, it was also showed increases in the ratio of sugar to alkali and the ratio of total nitrogen to nicotine, while decreases in the nicotine and starch content of the upper leaves of flue-cured tobacco under the same spraying treatment. And, the improvement was better under combination than single application treatment, especially for yield, the proportion of superior tobacco leaves, total sugar content and reducing sugar content of baking tobacco leaves （P〈0.01）. In conclusion, the combination application of GA3 50mg/L and IAA 30mg/L was the best treatment to improve carbon and nitrogen metabolism resulting in enhancement of quality in upper leaves of flue-cured tobacco.