为探明威宁黑石烟区烤烟云烟87的最佳移栽期和打顶时期组合，以进一步提高上部烟叶品质，本试验采用双因素随机区组设计，设置3个移栽期(4月10日、4月20日、4月30日)和3个打顶时期(现蕾、初花、盛花),共组成9个组合处理(T1—T9),研究移栽期和打顶时期互作对烤烟上部叶碳代谢产物含量、关键酶活性及相关基因表达量的影响。结果表明，不同移栽期均以初花打顶最有利于促进烤烟上部叶碳代谢产物(总糖、还原糖和淀粉)的积累，总体以4月30日移栽的初花打顶处理(T8)表现较优；上部叶转化酶(INV)活性以4月10日移栽的现蕾打顶处理(T1)和4月20日移栽的初花打顶处理(T5)的较高；蔗糖合成酶(SS)活性则以4月30日移栽的现蕾打顶处理(T7)和初花打顶处理(T8)的较高；上部叶转化酶基因(NtINV)相对表达量以T5处理以及4月30日移栽的盛花打顶处理(T9)的较高；蔗糖合成酶基因(NtSS)相对表达量以4月20日移栽的盛花打顶处理(T6)以及T9处理的较高。烤后上部叶的总糖、还原糖和淀粉含量均以4月10日移栽的盛花打顶处理(T3)和T8处理的较高，化学成分协调性表现较好，有利于烟叶品质的提升。相关性分析结果表明，鲜烟叶总糖含量与烤后烟叶淀粉含量呈显著正相关，鲜烟叶还原糖含量与烤后烟叶淀粉含量呈极显著正相关。综上可知，威宁黑石烟区以4月30日移栽结合初花打顶最有利于上部烟叶的碳代谢活动和品质提升。

To explore the optimal transplanting time and topping period combination for Yunyan 87 flue-cured tobacco in the Heishi tobacco area of Weining, and to further improve the quality of upper tobacco leaves, this experiment used a two-factor randomized block design with transplanting time and topping period as factors. Three transplanting times(April 10, April 20, April 30) and three topping periods(budding, early flowering, full flowering) were set, forming a total of nine combination treatments(T1 to T9), and their interaction effects on content of carbon metabolites, key enzyme activities, and related gene expression in upper leaves of flue-cured tobacco were studied. The results showed that under different transplanting times, topping at early flowering was the most favorable period for promoting the accumulation of carbon metabolites(total sugar, reducing sugar and starch) in upper leaves with the treatment of topping in early flowering period and transplanting on April 30(T8) showing the best. The activity of invertase(INV) in upper leaves was higher in the treatments of topping in budding period and transplanting on April 10(T1) and topping in early flowering period and transplanting on April 20(T5). The sucrose synthase(SS) activity was higher in the treatments of T7(topping in budding period and transplanting on April 30) and T8. The relative expression of the INV gene NtINV was higher in T5 and T9(topping in full flowering period and transplanting on April 30) treatments. The relative expression of the SS gene NtSS was higher in the treatments of T6(topping in full flowering period and transplanting on April 20) and T9. The contents of total sugar, reducing sugar and starch in cured upper leaves were higher in T3(topping in full flowering period and transplanting on April 10) and T8 treatments, and the chemical composition coordination performed better, which were beneficial for improving tobacco leaf quality. The results of correlation analysis showed that the total sugar content in fresh tobacco leaves was significantly positively correlated with the starch content of cured tobacco leaves, and the reducing sugar content of fresh tobacco leaves was extremely significantly positively correlated with the starch content of cured tobacco leaves. In summary, it could be concluded that transplanting on April 30 combined with topping in early flowering periodwas the most beneficial for the carbon metabolism activity and quality improvement of upper tobacco leaves in the Heishi tobacco area of Weining.