中文摘要：

比较了2个生菜品种和2个小白菜品种在两种浓度（0.5剂量、1.0剂量）营养液中水培的叶片数、叶部横径、株高、叶绿素含量、根系、单株鲜重、Vc含量和硝酸盐积累等生长特性和品质指标。结果表明,不同蔬菜种类对营养液浓度要求有显著差异,不同蔬菜品种也表现出不同的生长特性。与0.5剂量营养液浓度相比,1.0剂量营养液浓度促进或保持生菜生长发育,显著降低生菜硝酸盐含量。0.5剂量营养液有利于小白菜生长,显著提高小白菜Vc含量,有效减少硝酸盐积累。供试的小白菜和生菜品种在不同浓度水培营养液下叶片数趋于一致。意大利奶油生菜叶部横径小于弘农生菜叶部横径,但根系明显长于弘农生菜根系。小白菜叶绿素含量显著高于生菜叶绿素含量。0.5剂量下意大利奶油生菜单株鲜重显著高于该浓度下的五月慢小白菜单株鲜重。小白菜Vc含量在不同浓度水培营养液下均显著高于生菜Vc含量。较低浓度营养液下四月慢小白菜的Vc含量最高,而较高浓度营养液更有利于五月慢小白菜Vc含量积累。

英文摘要：

Four cultivars of lettuce and pakchoi were used in hydroponics culture under two different solution concentrations（0.5 and 1.0 dosage）,and several growth parameters were investigated including leaf number,leaf partwidth,plant height,leaf chlorophyll content,root length,plant fresh weight,vitamin C（Vc） content and nitrate accumulation.The results indicated that the vegetable types varied on optimal solution concentration,and different vegetable cultivars exhibited specific growth characteristics.Compared with 0.5-dosage concentration,the 1.0-dosage solution promoted or kept the lettuce growth,and decreased significantly the nitrate content.Solution of 0.5-dosage was beneficial for pakchoi growth,increased significantly the Vc content and inhibited the nitrate accumulation in pakchoi.The leaf number showed no difference in the four different vegetable cultivars in lettuce and pakchoi.The Italy cream lettuce had less leaf part width and longer root length than Hongnong lettuce.The chlorophyll content in pakchoi was significantly higher than that of lettuce.Under 0.5-dosage solution,the plant fresh weight of Italy cream lettuce was significantly higher than that of Wuyueman pakchoi.The Vc content in pakchoi was significantly higher than that of lettuce under all growth conditions.Under low concentration solution,Siyueman pakchoi had the highest content of Vc,while the relatively higher solution concentration was beneficial to Vc accumulation in Wuyueman pakchoi.