Abstract: Effects of supplemental lighting with different light qualities on the growth and physiological characteristics of seedlings of cucumber ‘Zhongnong 21’ and ‘Zhongnong 27’, pepper ‘Juwuba 5’ and ‘Zhenyan 6’, tomato ‘Israel Hongfeng’ and ‘Holland Hongfen’ were studied. The light emitting diode (LED) with different light qualities(red light, yellow light, green light, red+blue light and blue light) were used as supplemental lighting. The experimental results showed that the effects of supplemental lighting with different light qualities on different vegetable seedlings were obvious, but not identical. Generally speaking, the growth of seedlings were remarkably effected by red LED and red+blue LED, the stem diameter, fresh/dry weight and healthy index of the seedlings were significantly higher than those of the control (no supplemental lighting), and the soluble sugar content of cucumber ‘Zhongnong 21’, tomato and pepper seedlings were significantly increased as well. The maximal healthy index and dry weight of pepper ‘Juwu ba 5’ were obtained with blue LED. Chlorophyll and carotenoid content of cucumber and tomato ‘Israel Hongfeng’ seedlings were significantly increased by red or yellow LED. The results suggested that supplementing red or red + blue light could accelerate the growth of the vegetable seedlings and benefit the breeding of healthy seedling, but appropriate readjustment is necessary according to the different vegetable species and cultivars.

Key words: cucumber, tomato, pepper, light quality, seedling, growth, physiological characteristics