Effect of nitrogen nutrition on the free amino acid composition in tobacco plant

Nitrogen nutrition has great influences not only on the growth, but also on leaf quality of tobacco. There have been many reports on the nitrogen nutrition of tobacco, in which various nitrogen constituents such as amino acids and related compounds have been analyzed. But definite conclusions were often hard to be drawn out, since sometimes the work was limited by the failure of finding suitable chemical techniques. The recent development of paper chromatographic methods, however, has made possible to detect the individual amino acids, and has provided a new approach to the study of nitrogen nutrition of tobacco. Using the paper chromatographic techniques, the effects of nitrogen form, the effect of sulfur nutrition and excess of chlorine on free amino acid composition of tobacco leaf have been reported by the authors (1). The next step of the work presented here was undertaken for the quantitative study of the effect of nitrogen nutrition on free amino acid content of tobacco cultured for commercial purpose employing the amino acids estimation method developed by MOORE and STEIN (2) (3).