Abstract: Lettuces of red, purple and green leaves were planted with hydroponics, and the spectral absorbance and nutritional quality of the lettuces were studied. The results showed the curves of the photosynthetic pigments absorbing spectrum for three leaf-color lettuce cultivars were the same. Spectral absorbance of the three kinds of lettuces were higher at 330一380 nm,380一500 nm and 640一690 nm,among which the absorbance at 330一380 nm was the highest. Spectral absorbance of green leaves lettuce at high absorbed spectrums were remarkably lower than that of red and purple lettuce. And the red lettuce had a spectral absorbance peak at 380 nm. All kinds of photosynthetic pigments of red lettuce and purple lettuce were significantly higher than green lettuce. However there was no significant difference on biomass yield. The differences of the concentrations of phenol, flavonoid,rouble surgar,ascorbic acid between three kinds of lettuces were unremarkable,but the concentrations of anthocyanin differed great1y , as the sequence of red lettuce>purple lettuce>green lettuce.

Key words: Lettuce, Spectral absorbance, Nutritional quality, Leaf color, Cultivar

CLC Number: 

• S636.01