NITROGEN AND CARBOHYDRATE POOLS OF 2 RHIZOME TYPES OF PHRAGMITES-AUSTRALIS (CAV) TRIN EX STEUDEL

Carbohydrate and total nitrogen contents as well as free amino acid (F AA) concentrations were determined in distinct types of rhizomes of tw o genetically homogeneous stands of reed (Phragmites australis (CAV.) TRIN. ex STEUDEL) differing in morphology, productivity and nutrient s upply in order to evaluate the storage capacity of vertical rhizomes a nd expansion rhizomes. The expansion rhizomes possess significantly hi gher amounts of FAA and of total nitrogen but similar carbohydrate con centrations in comparison to the vertical rhizomes. However, no signif icant differences were found for total nitrogen, FAA and total carbohy drates between both investigated stands indicating a comparable storag e capacity of rhizomes independent of nutrient availability. Only the composition of the FAA pool varied in the alanine/asparagine ratio pro bably influenced by the oxygen supply of the rhizome/root system.