硫对设施水培大蒜光合特性和鳞茎品质的影响

在设施条件下，采用营养液培养大蒜，研究不同施硫水平对其光合特性、鳞茎质量及品质的影响。结果表明，在施硫水平0 ~ 2.25 mmol · L-1范围内，光合速率（Pn）、叶绿素含量、气孔导度（Gs）、蒸腾速率（E）和鳞茎质量随施硫量增加而升高，至硫浓度2.25 mmol · L-1时达最高。鳞茎品质指标除可溶性蛋白质外，随植株生长而逐渐升高。在不同硫处理间，鳞茎中大蒜素、可溶性糖和游离氨基酸和蒜薹中大蒜素、可溶性糖、维生素C及游离氨基酸含量均以2.25 mmol · L-1硫处理最高，分别比不施硫处理增加48.82%、127.92%、63.58%、10.61%、63.30%、29.07%和74.16%。营养液中硫含量为3.75 mmol · L-1时，鳞茎中蛋白质含量最高。大蒜二次生长指数在一定硫浓度范围内，随硫水平的升高而降低，而后随施硫量的升高变化不显著。

Effects of Sulfur Content in Nutrient Solution on Photosynthetic Characteristics and Quality of Garlic

Effects of different sulfur level on photosynthetic characteristics, fresh weight and qualities of garlic were studied by nutrient solution. The results showed when sulfur content was 2.25 mmol · L-1, the photosynthetic parameter (Pn, Gs, E), photosynthetic pigment contents in garlic leaf and the fresh weight of bulb were higher. Quality indicators of bulb (except the soluble protein) were increased gradually with plant growth. Among the different sulfur level, the allicin, soluble sugar and free amino acid contents in bulb of garlic and the allicin, soluble sugar, vitamin C and free amino acid contents in bolt were increased by 48.82%, 127.92%, 63.58%, 10.61%, 63.30%, 29.07% and 74.16%, respectively. Higher content of sulfur (3.75 mmol · L-1) increased the contents of soluble protein in bulb. At a certain range of sulfur concentrations, with the increase in sulfur level, the garlic branching index decreased and then had no significant change with the increase of sulfur level.