CAPACITY OF HIGHER-PLANTS FOR OXIDATION OF AMMONIUM TO NITRATES

We studied formation of endogenous nitrate from [N-15]-ammonium in exp eriments with plants grown under sterile conditions from surface-steri lized seeds and with plants obtained from apical meristems by the meth od of tissue culture. It is demonstrated that nitrification proceeded extremely slowly and depended on the plant species and the trend of ph ysiological processes. The corn plants most active in this regard oxid ized in 4 weeks only 0.04% of all ammonium nitrogen introduced to the nutrient medium at the outset of vegetation.