植物切断根のイオン吸収測定の改良法ならびにその塩生植物・中生植物根への応用

An improved method for measureing ion flow through excised roots is described. The excised roots were bathed in monocation solution containing 5 mM glucose (for active transport conditions) or 1 mM KCN and 0.5mM vanadate (for passive transport conditions). The ion uptake was measured under applied pressure of 110 cm H_20 using ion chromatography. The ion transport rates were expressed on the basis of root surface area which was estimated from salt adhesion data. The present method was successfully applied to non-halophyte and halophyte roots. The results showed that the ion flow rates were much higher in halophyte roots than in non-halophyte ones. Halophyte roots (samphire, saltwort and reed) absorbed K^+ and <Na>^^^+ at a similar rate, while non-halophyte roots (spinach and cucumber) showed a selective uptake of K^+.