Comparison of inorganic elements and epidermis structures in healthy and rusty ginseng

摘要

The ultrastructural characteristics of epidermis isolated from healthy and rusty ginseng roots (Panax ginseng) were observed by scanning electron microscopy, and the distribution profiles of inorganic elements were also examined by energy dispersiveX-ray analysis. The epidermis of rusty ginseng was thick and cell walls were severely disrupted whereas the epidermal image of healthy ginseng showed relatively thin, clear and rectangular structures. A high amount of rod-shaped bacteria was found in rusty ginseng and cells near the bacteria were degraded. The bacterial density in epidermis of rusty ginseng ranged from 2.9 x 106 to 3.5 x 107 CFU/g fresh weight, while that of healthy ones was from 4.7 x 102 to 1.2 x 103 CFU/g. Artificial inoculation ofbacteria isolated from rusty ginseng induced symptoms similar to rusty ginseng. The mineral contents including Al, Si and Fe were higher in the epidermis of rusty ginseng, but K content was lower compared to healthy ones.