钙对水培大蒜光合特性和品质的影响

 在水培条件下，营养液设6个钙浓度（0、1.0、2.0、3.0、4.0和5.0 mmol · L^-1），研究钙对大蒜光合特性、食用器官（蒜薹和鳞茎）钙含量及品质的影响。结果显示：蒜薹和鳞茎钙含量随营养液钙浓度的增加而增加；在钙浓度0 ~ 3.0 mmol · L^-1范围内，大蒜叶片色素含量、净光合速率（P_n）、蒸腾速率（E）及气孔导度（G_s）随钙浓度的升高而升高，而后则随钙浓度的升高而降低；蒜薹的鲜质量、直径及抽薹率和鳞茎的鲜质量及横径均随营养液钙浓度的升高而呈现先增大后减小的趋势，在3.0 mmol · L^-1钙浓度下最大；同时，蒜薹和鳞茎中大蒜素、可溶性糖、维生素C、游离氨基酸及可溶性蛋白含量的变化趋势也是先随钙浓度的升高而升高，而后随之下降，在3.0 mmol · L^-1钙浓度下达到最高值，比低钙浓度（1.0 mmol · L^-1）处理分别增加54.7%和72.1%、33.9%和33.9%、11.5%和5.2%、19.3%和21.5%、32.6%和29.6%。由此可见，水培条件下栽培大蒜的钙浓度以3.0 mmol · L^-1为好。

Effects of Calcium on Photosynthetic Characteristics and Quality of Garlic

In this experiment，the effects of calcium in nutrient solution on calcium content，photosynthetic characteristics and qualities of garlic were studied. Six different Ca²⁺ concentrations at 0，1.0，2.0，3.0，4.0，5.0 mmol · L^-1 were designed. The results indicated that the calcium contents of garlic bolt and bulb were increased with the increase of calcium concentrations. When the calcium concentrations were in the range of 0–3.0 mmol · L^-1，the pigment contents and photosynthetic parameters（P_n，E，G_s）of garlic leaves were enhanced with the increase of calcium concentrations，then they were decreased with the increase of calcium concentrations. The fresh weight of bolt and bulb，the bolt diameter，the bolting rate and the transverse diameter of bulb were increased at first and then decreased with the increase of calcium concentrations，these shape indexes under 3.0 mmol · L^-1 treatment were the highest. At the same time，the contents of allicin，soluble sugar，vitamin C，free amino acid and soluble protein in bolt and bulb were also improved with the increase of calcium concentrations ranging from 0 to 3.0 mmol · L^-1，these  indexes under 3.0 mmol · L^-1 treatment were increased by 54.7% and 72.1%，33.9% and 33.9%，11.5% and 5.2%，19.3% and 21.5%，32.6% and 29.6% compared to the treatment of 1.0 mmol · L^-1 calcium concentration，then they were minished with the increase of calcium concentrations greater than 3.0 mmol · L^-1. Thus it can be seen that，the 3.0 mmol · L^-1 calcium concentration was the best treatment to garlic under hydroponic condition.