| light spectrum energy distribution play an important role in plant development, morphogenesis, metabolism and gene expression. Compared with those traditional lamps, the improved features of the light-emitting diode (LED) include smaller mass and volume, a longer life, and a single wavelength, the light wavelength was coincidence with the spectrum that photosynthesis and morphogenesis were needed. Due to these unique characteristics, there is the suggestion that LED may be suitable for the culture of plants in a controlled environment. The different conditions are contained by using led. The effect of different light spectrum energy distribution on the growth and development, flowering stage characters, yield and qualities of tomato were studied. The results are as follows.1. plants under blue light, complex of light (RB、RBG) treatment grow stronger and have larger root-shoot ratio and also have smaller specific leaf area, but the red light have the opposite effect. Complex of light benefit the growth and morphogenesis of seedlings. Monochrome red, yellow and green light induced seedling spindling and blue can inhibit the effects. Under blue light treatment plants exhibited highest total soluble sugar content, total amino acid content, and the dry weight is also the largest. The root activity and total starch content of tomato which under complex of light (RBG) treatment is highest. Complex of light (RB) made the leaves show highest photosynthetic rate and enzyme activity and accelerate carbon and nitrogen balanced distribution in leaves, crowns and roots. Meanwhile, the density of stomata of tomato leaves is higher and the area of stomata, stomata area per unit leaf area is larger under blue light, complex of light (RB、RBG). Though the total sucrose of tomato which under yellow light treatment is highest, other kinds of indexes are smaller and it has unfavorable effect on growth and development of seedling.2. plants under PPFD of 50μmol·m-2·s-1 treatment have larger specific leaf area, content of chlorophyll, leave transmittance, the height and leaf area were increase with the prolonging treatment time. The chlorophyll fluorescence parameters such as ETR, OPSII. qP were lowest. The seedlings biomass were increase with Photon flux density, but the trend turned smaller even keeping steady under PPFD of 300μmol·m-2’·s-1. The seedlings have highest of content of soluble sugar, sucrose, amino acid under PPFD of 300μmol·m-2·s-1. and the content of starch was highest under PPFD of 450μmol·m-2·s-1. It was found that with increasing Photon flux density, the photosynthetic rate and chla/chlb of leave show a trend of decrease, but the pigment content have opposition trend. The content of MDA and soluble protein in leave under low Photon flux density were increasing as the prolonging processing time, high Photon flux density have smaller change. The CAT activity in the leave show gradual increase trend in first 21 d of treatment and then decreased rapidly. The SOD activity in the leave increased rapidly in first 7d of treatment and then declining gradually.3. The plant under B:R=1:1 light treatment show highest healthy index, lowest specific leaf area. Under the large and near ratio of B/R light, the content of chlorophyll and carotenoids and soluble protein in leave, plant fresh weight and dry weight were higher, but the chla/chlb was smaller. The root activity is highest under blue light, having a decrease trend with increasing red light ratio. The content of soluble sugar, sucrose, amino acid and starch of plants were largest under B:R=1:1 light treatment and smallest under B:R=1:3 light treatment. The photosynthetic rate is higher under blue light and smaller under dysprosium lamp. Under B:R=1:3 light treatment, the plants have higher enzyme activities.4. The plant under B:R=1:3 light treatment have early florescence, but number of the first inflorescence and pollen viability is lower, fruit number per plant and yield per plant is lowest. The plant under B:R=3:2 light treatment show highest fruit number per plant and yield per plant, having largest the content of soluble sugar, sucrose, amino acid, ascorbic acid of tomato fruit, and the sugar/acid is highest, the content of soluble protein of tomato is lower. The content of soluble and titratable acid of fruit were largest under B:R=1:1 light treatment, but other indexes is lower. Under monochrome blue treatment, fruit have highest content of soluble solids and lycopene. but the content of titratable acid and sucrose is lowest.It is concluded that blue light or complex of light (RB、RBG) benefit the growth and development of tomato seedling. It is bad effect on growth and development of seedling under too low or too high PPFD. The plants grow stronger and all kinds of indexes are larger under PPFD of 300μmol·m-2·s-1. It is the best Photon flux density for tomato seedling to grow. Large or near proportion of B/R light play positive effect on tomato seedling. Especially B:R=1:1, it is the best light to promote seedling grow and develop. B:R=3:2 treatment benefit the formation of fruit qualities. |
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