Anatomical difference of neck tissue of cut roses as affected by bent neck and preservative solution

摘要

This experiment was conducted to investigate the anatomical changes of neck tissue held in deionized water and preservative solution containing sucrose, 8-hydroxyquinoline sulfate (HQS), and ethionine in 'Red Velvet' roses. 'Red Velvet' roses showedfrequent bent neck and short vase life. Lignins in xylem, phloem and intervascicular cambium of neck were stained in red by phloroglucine. More lignin was formed in the phloem tissue of neck in rose flowers held in preservative solution than those heldin deionized water. Neck strength of cut rose could be related to increase of lignin contents, and this in turn prevented bent neck and extended vase life. Parenchyma cells in neck of rose flowers held in deionized water had thinner cell walls and less starch grains at senescence, but those of flowers held in preservative solution had thicker cell walls and more starch grains. Also, xylem and phloem tissues around cambium were filled with starch grains. These starch grains would be used as energy sourceof rose flowers and extended vase life. Globular crystals were observed in the inner part of cells and had a shape of large thorn. These crystals accumulated in cell walls prevented the activity of cell wall decomposition or increase cell wall permeability, making use of composition material of cell wall.