Distribution Characteristics of Magnesium in Flue-cured Tobacco in China and its Relationship with Chemical Composition and Organic Acids

In order to explore the relationship between Mg content of flue-cured tobacco and quality of tobacco leaves, 249 tobacco leaf samples in 2018 were used in studying the variation characteristics of Mg content in flue-cured tobacco in different producing areas and parts, as well as the relationship with chemical composition and organic acid contents. The results showed that Mg contents of flue-cured tobacco in tobacco-growing areas of China mainly ranged from 0.16% to 0.84%, with an average value of 0.40%. Mg content of flue-cured tobacco was significantly negatively correlated with potassium content and potassium-chlorine ratio, and was significantly positively correlated with chlorine content and nitrogen-base ratio. The contents of oxalic acid, malonic acid, lactic acid, levulinic acid, malic acid, citric acid and total organic acid in the refractory acid had a significant correlation with Mg content of flue-cured tobacco. Suitable Mg content of flue-cured tobacco is beneficial to harmonize the chemical composition of tobacco leaves and the content of organic acids in flue-cured tobacco, and can improve the intrinsic quality of tobacco leaves.