The differences of pigment compositions in leaf chloroplast between sun and shade plant were analyzed to investigate the photo-induced destructive effects on shade species under the strong light. Ginseng was selected as a C-3 shade plant, soybean as C-3 sun species and corn as C-4 malate forming sun species. To study the effects of light, ginseng was divided into two subgroups; the 1 and 2 lines received sunlight a little more than those of 3 and 4 lines.
Total amounts of chlorophylls, carotenes and xanthophylls were not considerably different among 3 and 4-lined ginseng, soybean and corn. However, the amounts of the three components of 1 and 2-lined ginseng and the chlorophylls content in corn leaves were smaller than those of others. The molar ratio of lutein to total carotenoids was significantly high in ginseng, that of violaxanthin was considerably high in corn and that of neoxanthin the highest in 1 and 2-lined ginseng among tested samples.
Chlorophylls to carotenes ratio was 16.0 and highest in ginseng, 13.2 in soybean and 12.0 in corn.
In 1 and 2-lined ginseng, the molar ratios of lutein and carotenes were lower while those of neoxanthin and violaxanthin were higher than those of the samples of more light.
It was noticeable that an antheraxanthin-like epoxy carotenoid detected in soybean and corn leaves extracts was not observed in ginseng leaf extract.
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