Abstract:

Sophora japonica L. Seedlings were grown under atmospheric CO₂ enrichment levels of 600、800、1000、1500 and 2000?μmol·mol^-1 within film greenhouse with monitorring CO₂ concentration by BEM 1 system for 3～5 hours every day and lasted 80 days CO₂ enrichment promoted significantly seedling growth,1500?μmol·mol ^-1 CO₂2 level was proved to be best one among 5 CO₂ enrichment levels,with 41.45%、 44.95% and 160% increase of dry weight、starch content and photosynthetic rate respectively. stomatal resistances of seedlings grown under high CO₂ enrichment levels were higher than the control,which was benefical to improve water use efficiency(WUE),total amino acid contents was lower,which increased C/N of seedlings,microstructure of chloroplast shown that starch acclimation of the seedlings grown under high CO₂ level reduced grana formation,which may result in down regulation on photosynthesis,thus,1000～1500?μmol·mol^-1 CO₂ enrichment level with N fertilizer was recommended to Sophora japonica L. seedling cultivation

Key words: CO₂2enrichment, Sophora japonica L., Seedling growth, Photosynthesis