Germination and growth characteristics of Dendropanax morbifera Lev. by sowing methods and shading conditions

Dendropanax morbifera LEV. belongs to family Araliaceae is a subtropical broad-leaved evergreen tree distributed in Korea, Japan, China and Taiwan. D. morbifera is highly valuable forest resource used not only as ornamental trees but also golden lacquer and medicinal materials in Korea. However, natural habitats of D. morbifera are locally distributed in warm-temperature region of Korea. This study was carried out to obtain basic information for the improvement conditions of germination rate according to the various sowing methods and proper shading conditions to produce superb seedlings. We measured the seed germination rate (GR) and germination performance index (GPI) of D. morbifera under the various conditions of sowing time, pre-chilling and PEG (polyethyleneglycol) treatments to find out the promotive way of germination. In addition, we had observed the morphological-physiological changes of D. morbifera seedlings by different shading conditions. As a result, the seed of D. morbifera was showed the highest germination rate when the seeds were sowed in March with more than 30 days pre-chilling treatment and -2.0Mpa PEG treatment. However there was no statistical difference between PEG treatments. D. morbifera showed the highest values in the leaf area (TLA), H/D ratio, chlorophyll contents and photosynthetic capacity at 95% shading condition and those factors were increased with a statistical significance by decreasing light level. On the other hand, at 50% shading condition, D. morbifera had maximum value in dry-weight of root and seedling quality index (SQI) but minimum T/R ratio. Those results suggested that the optimum shading condition of D. morbifera for the vigorous seedling was approximately 50% level.