The effects of organic nitrogen sources on growth of cell cultures of Douglas-fir

In order to establish rapidly growing, friable cell cultures of Douglas-fir ( Pseudotsuga menziesii Mirb. (Franco)], the effects of organic sources of nitrogen on growth were investigated. Of the nitrogen sources studied, including allantoin, allantoic acid, glutamine and glutamic acid, all were capable of increasing growth. Glutamine (50 m M ) produced the most marked increase in growth boosting dry weight production to a level of four times that of controls. Glutamine additions also eliminated the lag phase of growth and caused cells to become densely cytoplasmic. Results are discussed in relation to the pathway for assimilation of nitrogen.