Abstract: 【Objective】The effects of different light times on the growth and development of different leaf vegetables were studied, and the growth and development rules were analyzed.【Methods】Radix gendaria, Italian year-round bolt-resistant lettuce 602, Romaine lettuce and four seasons of health were used as experimental materials LED light sources were used to fill light at night with different light times. The effect of extending different fill light times（6, 9, 12 h）on the growth and nutritional quality of hydroponic leafy vegetables was comprehensively evaluated by using the member function method.【Results】Reasonable extension of light time could promote the growth rate and improve the nutritional quality of 4 leaf vegetables. The extension of 9 h of supplemental light was more beneficial to accelerate the leaf growth rate and improve the nutritional quality of Italian year-round bolt-resistant lettuce 602. In addition to that, the extension of 12 h of light supplementation was more conducive to promoting the overall growth and development of genda and Roman callie lettuce and improving the nutritional quality. As a result, the maximum leaf length, maximum leaf width, leaf number, vitamin C, soluble sugar and soluble protein of romaine lettuce 602 increased by 15.7%, 6.2%, 10.2%, 50.0%, 24.2% and 2.7%, respectively, when the light duration was extended from 6 h to 9 h. The four seasons health increased by 3.5%, 35.6%, 11.1%, 4.4%, 9.9% and 12.2% respectively. When light duration was extended from 6 to 12 h, plant height, root length, maximum leaf length, maximum leaf width, leaf number and soluble protein increased by 15.6%, 20.3%, 7.1%, 15.6%, 9.3% and 43.5%, respectively. Romaine lettuce rose 18.0%, 14.2%, 3.0%, 15.9%, 20.8%, and 81.1%, respectively.【Conclusion】The growth and nutritional quality indexes are the best when Gendaria and Callie lettuce are cultivated for 12 h with extended light supplement, and the growth and nutritional quality indexes are the best when Italian year-round bolt-resistant lettuce 602 is cultivated for 9 h with extended light supplement.

Key words: light duration; LED; hydroponic leafy vegetable; growth and development; nutritional quality

摘要： 【目的】研究不同光照时间对不同叶菜生长发育的影响，并分析其生长发育规律。【方法】以根达菜、意大利全年耐抽苔生菜602、罗马嘉丽生菜、四季养生为供试材料，LED作为人工光源（功率14 w，1.2 m），采用可循环营养液（pH值5.8），待叶菜长至二叶一心时移栽到深夜流水培槽中（360 L），设置夜间补光时间为6、9和12 h。【结果】合理延长光照时间可促进4个叶菜类品种的生长速率以及提升其营养品质。延长补光9 h更有利于加快意大利全年耐抽苔生菜602和四季养生的叶片生长速度，并改善其营养品质；而延长补光12 h更有利于促进根达菜和罗马嘉丽生菜的整体生长发育和改善营养品质。故光照时长由6 h延长至9 h，意大利全年耐抽苔生菜 602 最大叶长、最大叶宽、叶片数、Vc、可溶性糖、可溶性蛋白分别增加了 15.7%、6.2%、10.2%、50.0%、24.2%和2.7%；四季养生分别增加了3.5%、35.6%、11.1%、4.4%、9.9%和12.2%。光照时长由6 h延长至12 h，根达菜株高、根长、最大叶长、最大叶宽、叶片数和可溶性蛋白分别增加了15.6%、20.3%、7.1%、15.6%、9.3%和43.5%；罗马嘉丽生菜分别增加了18.0%、14.2%、3.0%、15.9%、20.8%和81.1%。【结论】根达菜、罗马嘉丽生菜延长补光12 h栽培时生长及营养品质指标最优，意大利全年耐抽苔生菜602、四季养生延长补光9 h栽培时生长及营养品质指标最优。

关键词: 光照时间, LED, 水培叶菜, 生长发育, 营养品质