| Abstract: | Carbohydrate and total nitrogen contents as well as free amino acid (FAA) concentrations were determined in distinct types of rhizomes of two genetically homogeneous stands of reed (Phragmites australis (Cav.) Trin. ex Steudel) differing in morphology, productivity and nutrient supply in order to evaluate the storage capacity of vertical rhizomes and expansion rhizomes. The expansion rhizomes possess significantly higher amounts of FAA and of total nitrogen but similar carbohydrate concentrations in comparison to the vertical rhizomes. However, no significant differences were found for total nitrogen, FAA and total carbohydrates between both investigated stands indicating a comparable storage capacity of rhizomes independent of nutrient availability. Only the composition of the FAA pool varied in the alanine/asparagine ratio probably influenced by the oxygen supply of the rhizome/root system. |
