This study describes the efficient method for the discrimination of 'Cheonryang' in Panax ginseng Meyer using a STS primer. A total of 208 STS primers were applied to polymerase chain reaction (PCR) amplification for discriminating Korean ginseng cultivars. Co-dominant polymorphic band patterns were generated with two primers, MFGp 0019, MFGp 0248, and successful identification of 'Cheonryang' was achieved from out of 11 Korean ginseng cultivars. Two different sizes of DNA band patterns were detected with MFGp 0019 primer. Ten Korean ginseng cultivars shared the same size of amplified DNAs (389 bp), but 'Cheonryang' showed a different size. Thus 'Cheonryang' can be efficiently distinguished from the other ten ginseng cultivars by using the MFGp 0019 primer. In the case of MFGp 0248, two different sizes of DNA band patterns were detected in the eleven ginseng cultivars. Same sized amplified DNA bands (307 bp) were shown in five cultivars (Chunpoong, Gopoong, Kumpoong, Cheongsun, Sunhyang) and 254 bp sized DNA bands were identified in the other 6 cultivars (Yunpoong, Sunpoong, Sunun, Sunone, Cheonryang, K-1). In conclusion, the two STS primers, MFGp 0019, and MFGp 0248, provide a rapid and reliable method for the specific identification of 'Cheonryang' cultivar from a large number of samples.

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.

The transcriptomes of four ginseng accessions such as Cheonryang (Korean ginseng cultivar), Yunpoong (Korean ginseng cultivar), G03080 (breeding line of Korean ginseng), and P. quinquefolius (American ginseng) was characterized. As a result of sequencing, total lengths of the reads in each sample were 156.42 Mb (Cheonryang cultivar), 161.95 Mb (Yunpoong cultivar), 165.07 Mb (G03080 breeding line), and 166.48 Mb (P. quinquefolius). Using a BLAST search against the Phytozome databases with an arbitrary expectation value of 1E-10, over 20,000 unigenes were functionally annotated and classified using DAVID software, and were found in response to external stress in the G03080 breeding line, as well as in the Cheonryang cultivar, which was associated with the ion binding term. Finally, unigenes related to transmembrane transporter activity were observed in Cheonryang and P. quinquefolius, which involves controlling osmotic pressure and turgor pressure within the cell. The expression patterns were analyzed to identify dehydrin family genes that were abundantly detected in the Cheonryang cultivar and the G03080 breeding line. In addition, the Yunpoong cultivar and P. quinquefolius accession had higher expression of heat shock proteins expressed in Ricinus communis. These results will be a valuable resource for understanding the structure and function of the ginseng transcriptomes.