关键词: 烤烟, 海藻糖, 连作障碍, 土壤理化性质, 病情指数, 化学成分, 致香物质

Abstract: To clarify the effects of trehalose on soil vitality and flue⁃cured tobacco quality，and to address issues such as soil degradation and decreased flue⁃cured tobacco quality caused by long⁃term continuous cropping，using Yunyan 87 as the experimental material，experiments were conducted in long⁃term continuous cropping plots of flue⁃cured tobacco.We set three concentrations of trehalose（79.40，154.64，393.67 mg/L） and three application frequencies（once every 10，15 and 20 days），root irrigation was started 10 days after transplantation and was applied for 3 times in total，soil physicochemical properties，enzyme activity，microbial quantity and diversity，as well as flue⁃cured tobacco chemical composition，aroma causing substances，and disease index were measured at key growth stages of flue⁃cured tobacco.The results showed that the application of 393.67 mg/L trehalose every 15 days significantly improved soil nutrient content，enzyme activity，microbial diversity，and quantity. Among them，the organic matter content increased by 14.54% compared to the control（CK，equal amount of clean water applied every 15 days），soil enzyme activity increased by 15.07%—61.09% compared to CK，and soil microbialrichness index increased by 16.49% compared to CK.The application of 393.67 mg/L trehalose every 10 days had a better effect on the prevention and control of black shank disease，and the application every 15 days had a better effect on the prevention and control of bacterial wilt disease，with disease indices reduced by 6. 82% and 5.76% respectively compared to CK.The application of 393.67 mg/L trehalose every 15 days significantly increased the total sugar and potassium content of middle and upper flue⁃cured tobacco leaves，and promoted the accumulation of aromatic substances in flue⁃cured tobacco leaves.The total amount of aromatic substances in middle and upper flue⁃cured tobacco leaves increased by 30.81% and 31.11% respectively compared to CK.In summary，applying 393.67 mg/L trehalose for root irrigation every 15 days after transplanting flue⁃cured tobacco can significantly increase soil nutrient content and enzyme activity，promote chemical composition coordination and aroma substance accumulation in flue⁃cured tobacco leaves，effectively alleviate the accumulation of soil borne diseases in continuous cropping flue⁃cured tobacco fields，and comprehensively improve flue⁃cured tobacco leaf quality.

Key words: Flue?cured tobacco, Trehalose, Continuous cropping obstacle, Soil physicochemical property, Disease index, Chemical composition, Aromatic substance