Fractionation of Stable Isotopes of Nitrogen in Trapa japonica During Uptake of NH4+-N

Abstract

Trapa japonica grown hydroponically under various conditions with respect to different concentrations of NH4+-N to observe the fractionation of stable isotope of nitrogen occurred during uptake and assimilation. There was a significant variation in fractionation of nitrogen isotope during uptake from different levels of nitrogen by the plant. When plant absorbed a large amount of N from the solution, the lower enrichmentof δ15N value was observed in plant parts and the enrichment of δ15N value was decreased with the increase of nitrogen concentration in the medium. A linear relationship occurred during up take of nitrogen by T. japonica between fraction of nitrogen remaining inmedium (f) and fractionation factor (ε).