AIR IN XYLEM VESSELS OF CUT FLOWERS

Abstract

Until now all studies on the role of air emboli in the water uptake of cut flowers describe indirect methods to demonstrate the presencFe of air in the plant tissues. Using cut chrysanthemum flowers, this report is the first one that directly visualises both air and water in xylem ducts of cut flower stems, by observing transversal sections of frozen stalks in a cryo scanning electron microscope (cryo-SEM). After cryo-fixation frozen stems were sawed transversally at a desired height, polished with a cryo ultra mill, lightly etched, sputtered with platinum and investigated with the cryo-SEM. This method allows for detailed studies on the origin and fate of air emboli on water balance in cut flower stems.