Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9477594 | Aquatic Botany | 2005 | 17 Pages |
Abstract
Species differed in the nitrogen utilisation. In Glyceria, the relative tissue N content was higher than in Phragmites and was increased in NH4+ treated plants by 16%. The tissue NH4+ concentration (mean = 1.6 μmol g fresh wtâ1) was not affected by N treatment, whereas NO3â contents were higher in NO3â (mean = 1.5 μmol g fresh wtâ1) than in NH4+ (mean = 0.4 μmol g fresh wtâ1) treated plants. In Phragmites, NH4+ (mean = 1.6 μmol g fresh wtâ1) and NO3â (mean = 0.2 μmol g fresh wtâ1) contents were not affected by the N regime. Species did not differ in NH4+ (mean = 56.5 μmol gâ1 root dry wt hâ1) and NO3â (mean = 34.5 μmol gâ1 root dry wt hâ1) maximum uptake rates (Vmax), and Vmax for NH4+ uptake was not affected by N treatment. The uptake rate of NO3â was low in NH4+ treated plants, and an induction phase for NO3â was observed in NH4+ treated Phragmites but not in Glyceria. Phragmites had low Km (mean = 4.5 μM) and high affinity (10.3 l gâ1 root dry wt hâ1) for both ions compared to Glyceria (Km = 6.3 μM, affinity = 8.0 l gâ1 root dry wt hâ1). The results showed different plasticity of Phragmites and Glyceria toward N source. The positive response to NH4+-N source may participates in the observed success of Glyceria at NH4+ rich sites, although other factors have to be considered. Higher plasticity of Phragmites toward low nutrient availability may favour this species at oligotrophic sites.
Related Topics
Life Sciences
Agricultural and Biological Sciences
Aquatic Science
Authors
Edita Tylova-Munzarova, Bent Lorenzen, Hans Brix, Olga Votrubova,