This study was performed to investigate the effects of sowing density and number of seeds sown on the emergence rate and growth characters of Panax ginseng C. A. Meyer under direct sowing cultivation in a blue plastic greenhouse. Ginseng seedlings, derived from seeds sown directly at different densities (90, 108, 135, and 162 seeds per 162m2), were cultivated in sandy loam soil within a blue plastic greenhouse. In contrast to the emergence rate, which decreased with an increase of sowing density, number of survival plant showed an increasing trend. Interestingly, the emergence and number of survival plant were significantly enhanced when 2 or 3 seeds were sown per hole compared with when one seed was sown per hole. Growth of the aerial parts of ginseng were not markedly influenced by sowing density or the number of seeds sown. However, chlorophyll content (SPAD values) increased with an increase in sowing density. Root parameters, such as root length, diameter, and weight, and the number of lateral roots decreased with an increase in sowing density, but were not noticeably influenced by the number of seeds sown. Total saponin content was the highest in the treatment plot containing 135 seeds. Similarly, the content of each ginsenoside was also tended to be higher in this treatment than in other treatment plots. On the basis of the results obtained in this study, it was possible to determine the optimal sowing density and seed number for the direct sowing cultivation of ginseng in blue plastic greenhouse.

This study was performed to identify optimal harvesting time of ginseng seeds and to examine the effect of GA3 treatment for improvement of seed stratification rate. Ginseng seeds harvested from Land race, Chunpoong and Yunpoong cultivar in July 20 were tested for stratification rate. It was shown that stratification rates of land race, Yunpoong and Chunpoong cultivar were 94.1%, 93.1%, and 82.6%, respectively. Seeds of Chunpoong cultivar harvested 10-15 days later showed a comparable stratification rate to that of Land race, indicating that late harvest of Chunpoong seeds is beneficial for the increase of stratification rate. The higher stratification rate was found in mature seeds (92.3%) than immature seeds (37.8%), both of which were harvested in July 20. Stratification rate of mature seeds harvested in July 15 was 87.5%, demonstrating optimal harvesting time of ginseng seeds with higher stratification rate is after mid-July. An exponential growth of endosperms of ginseng seeds was observed from early June to mid-June and then slow growth was observed. There was no obvious growth of embryos from fertilization to mid-August. After the this time, embryos quickly grew until late October. Thus, appropriate stratification control is essential during the period (from early September to late October) in order to optimize embryo growth and development. While no increase of stratification rate was observed in seeds treated with 50 ppm of GA3, significant increases were observed in seeds treated with 100 ppm of GA3. At this concentration of GA3, the stratification rate of Land race, Chunpoong and Yunpoong cultivar was 95.0%, 95.3%, and 96.5%, respectively.

Salt stress is one of the major abiotic stresses affecting the yield of ginseng (Panax ginseng C. A. Meyer). The objective of this study was to identify bio-marker, which is early responsive in salt stress in ginseng, using proteomics approach. Ginseng plants were exposed to 5 ds/m salt concentration and samples were harvested at 0, 6, 12 and 18 hours after exposure. Total proteins were extracted from ginseng leaves treated with salt stress using Mg/NP-40 buffer and were separated on high resolution 2-DE. Approximately 1003±240 (0 h), 992±166 (6 h), 1051±51 (12 h) and 990±160 (18 h) spots were detected in colloidal CBB stained 2D maps. Among these, 8 spots were differentially expressed and were identified by using MALDI-TOF/TOF MS or/and LC-MS/MS. Ethylene response sensor-1 (spot GL 1), nucleotide binding protein (spot GL 2), carbonic anhydrase-1 (spot GL 3), thylakoid lumenal 17.9 kDa protein (spot GL 4) and Chlorophyll a/b binding protein (spot GL 5, GL 6) were up-regulated at the 12 and 18 hour, while RuBisCO activase B (spot GL 7) and DNA helicase (spot GL 8) were down-regulated. Thus, we suggest that these proteins might participate in the early response to salt stress in ginseng leaves.

This study investigated ginseng growth and ginsenoside contents after control a reserved ginseng cultivation land using various green manure crops for stable ginseng cultivation. Followings are results obtained from this research. After cultivate the green manure crops, microbial flora in soil was diversified, organic matter and total-N content increased, but salt content decreased. The highest output obtained from the wheat cultivated area among various green manure corps. Growth of shoot and root of two years old ginseng increased significantly at the green manure crop cultivated area. Specially, the wheat cultivated area was the most effective in growth. Also, the rate of the leaf discoloration at the aerial part and the rusty root at the root was the least at the wheat cultivation area. Meanwhile, the ginsenoside content was the most at the wheat cultivation area. Thus, the reserved ginseng cultivation land could be managed by cultivating wheat for effective ginseng growth.