Effects Of Sulfur Concentration In Nutrient Solution On Physiological And Biochemical Characteristics And Quality Of Garlic

Effects of different sulfur concentrations on physiological and biochemical characteristics, fresh weight and qualities of garlic were studied by nutrient solution. Two cultivars: JinXiang Violet Garlic and JinXiang White Garlic were tested in this research, based on Hoagland nutrient solution, six sulfur concentrations (0mmol·l-1, 0.75mmol·l-1, 1.50mmol·l-1, 2.25mmol·l-1, 3.00mmol·l-1, 3.75mmol·l-1) was treated to study the effects of sulfur on biology characteristic, photosynthesis, fresh weight and quality, contents of total N, total P, total K and S of garlic.The main results were as follows:1. The proper sulfur concentration in nutrient solution could raise the height, pseudostem diameter, the leaf sheath length and leaf area of JinXiang Violet Garlic and JinXiang White Garlic, which manufactured and stored more photosynthates for the late bolt elongation and bulb division, expansion. When sulfur concentration in nutrient solution more than 2.25mmol·l-1 was not conducive to the improvement of the above-mentioned indicators. Root activity was the highest, when sulfur concentration was 2.25mmol·l-1.2. At a certain concentration range of sulfur concentration (0~2.25mmol·l-1), the chlorophyll and carotenoid contents of garlic functional leaf increased gradually, when the concentrations of sulfur was higher than 2.25mmol·l-1, they declined. Leaf photosynthetic rate was the highest at 2.25mmol·l-1, in particular, into its fast growth period. When sulfur content in nutrient solution was 1.50mmol·l-1, the enzyme activity (POD activity, CTA activity, NR activity) were highest. SOD activity and soluble protein content of garlic leaves were highest at 2.25mmol·l-1.3. Sulfur promoted fresh weight of garlic. On the one hand, sulfur increased the transverse diameter of garlic, reduced branching index; on the other hand, sulfur increased yields of garlic. On fresh weight, one bulb of Violet Garlic was increased by 32.82%~67.34%, White Garlic increased by 16.90%~51.10%; the fresh weight of one Violet Garlic bolt was increased by 72.46%~141.86%, White Garlic increased by 48.64%~108.42%. The results showed that: the yields were the highest when sulfur concentration was 2.25mmol·l-1. 4. Sulfur has an impact on the quality of two varieties of garlic bulb and bolt. the allicin, soluble sugar, Vitamin C and free amino acid contents in bulb and in bolt were the highest when sulfur treated concentration in nutrient was 2.25mmol·l~-1. Soluble protein content in bulb and in bolt of Violet Garlic, with the sulfur concentration increased, showed an upward trend in a straight line, as well as White Garlic. Lower concentration of sulfur (1.50mmol·l~-1) increased the contents of soluble protein in bulb of Violet Garlic and White Garlic by 64.79%, 63.81%, respectively.5. The proper concentration of sulfur in nutrient solution could promote the contents of total N, total P, total K and S. At a certain concentration range, sulfur promoted absorption of total N and S, which showed a certain degree of positive correlation. The contents of total N and total P were the highest when concentration of sulfur was 2.25mmol·l~-1, followed by 1.50mmol·l~-1.