Abstract
We cultivated lettuce (Lactuca sativa) seedlings on 1-dimension clinostat under three different light conditions (2000-9000lux). Growth of seedlings was significantly promoted by SMG condition at 2000 and 4300 lux. At 9000lux, the growth rates reduced but the positive SMG effects remained. Contents of photosynthetic pigments in fresh weight bases were almost equivalent between control and SMG conditions but those of chlorophyll a and b significantly increased as the intensity of light irradiation decreased. Soluble sugar contents tended to decrease by SMG condition and/or by irradiation at lower light intensity. SMG condition for young seedlings resulted in an enhanced biomass of the plant bodies after subsequent cultivation in soil.
From these results, we concluded that SMG condition might be effective in reducing biological costs for anti-gravity stress and transportation and hence increasing growth rate and photosynthetic production in lettuce plants.
