Wang Zheng-yin

Quality Characteristics of Tobacco Leaves with Different Aromatic Styles from Guizhou Province, China

The relationships between chemical components and quality indexes were studied in the tobacco leaves with different aromatic styles. A total of 16 chemical components, 4 quality indexes, and 6 smoking quality indexes from 366 tobacco leaf samples with 4 different types of aroma from Guizhou Province, China, were subjected to principal component analysis and stepwise regression analysis. The tobacco leaves with different types of aroma showed remarkable difference in the contents of chemical components, quality indexes, and smoking quality indexes. The first principal factors (carbohydrates and nitrogen-containing compounds) of the chemical composition of the leaf were similar among different types of aroma, which showed that the quality of the leaf was mainly influenced by carbohydrates and nitrogen-containing compounds and their ratios. The factors for the second through the seventh principal components varied largely among various aromatic types, suggesting the contribution of other chemical components to the leaf quality. In addition, the smoking quality of four different aromatic leaves showed significant correlation with the different chemical components. The quality of tobacco leaves with different types of aroma was influenced by multiple factors, especially ecological conditions and culture techniques, which may provide guidance for directive cultivation of high-quality tobacco leaves.

Effect of phosphogypsum on nutrient balance and membrane defense enzyme of broomcorn in strongly acidic soils

Pot culture trials were conducted to probe into the effects of phosphogypsum on growth, nutrient balance and membrane defense enzyme of broomcorn in strongly acidic yellow soils. Results show that the broomcorn seedlings do not grow well without application of phosphogypsum or lime, even under sufficient nutrient supply. However, the seedlings grow normally after application of phosphogypsum or lime, which increases soil pH and at the same time decreases exchangeable Al concentration in strongly acidic soils. There is significantly quadratic correlation between seedling dry-weight (Yw) and phosphogypsum (X1) or lime (X2) dose. Regression equations for the relations are: Yw = 6.88+11.92 X1-1.65 X12, R = 0.983**; Yw = 6.88+6.39 X2-0.72 X22, R = 0.996**. Lime is superior to phosphogypsum in alleviating A1 toxicity and raising calcium content. But it is inferior to phosphogypsum in increasing available nitrogen, phosphorus and potassium in broomcorn seedling. After phosphogypsum application, phosphorus content in broomcorn seedling is 1.17~2.43 times that in lime treatment. Compared with lime treatment, phosphogypsum application increases nitrogen, phosphorus, potassium and calcium contents while sustaining moderate levels of N/P, N/K and K/P. This improves the balance between nitrogen, phosphorus, potassium and calcium in broomcorn plant. Phosphogypsum is superior to lime with regards increased activity of superoxide dismutase (SOD) and catalase (CAT), and decreased activity of peroxidase (POD) and proline content (Pro) in the leaves of broomcorn. Phosphogypsum could therefore be regarded as a strongly acidic soil ameliorant thatis superior to lime.