Vessel Elements of Panax ginseng C.A. Meyer

인삼 (Panax ginseng C.A. Meyer)의 도관요소

Vessel elements in lateral root, tap root, transition region, stem and mid vein of 1-year old, 3-year old and 5-year old ginseng (Panax ginseng C.A. Meyer) are studied with light microscope to clarify the distribution and differentiation of several kinds of vessel elements. Vessel elements are classified into five types such as ring vessel, spiral vessel, scalariform vessel, reticulate vessel and pitted vessel according to the secondary thickenings of cell wall. All of the five types are not observed in each organ, but diverse kinds of vessels are present in stem and mid vein compared with the underground organs such as tap root and lateral root. The length of vessel elements is longest (680$\mu$m) in stem and shortest (143$\mu$m) in tap root. The diameter of vessel elements is 19.0$\mu$m in tap root and the angle of perforation plate comes under 22$^{\circ}$-60$^{\circ}$. The degree of differentiation of vessel elements according to the length, diameter and angle of perforation plate of vessel elements is highest in tap root regardless of the age of ginseng. Three types of perforation plate such as scalariform, intermediate type of simple and scalariform, and simple perforation plate are observed. The vascular tracheids are characteristically observed in mid vein of 1-year old ginseng, and in transition region of 3 and 5-year old ginseng.