Background : Due to immature development of embryo in ripened berries, dehiscence process is required for the proper germination of ginseng seeds. Such process involves the preparation of the container with alternating layers of seed and moist sand. In order to make sand fully moist, water sprayer has been usually used by farmers, which is labor intensive, time consuming and causing uneven sand moisture. Methods and Results : In this study, we investigated the effects of different stratification methods on dehiscence ratio of ginseng seeds. Ginseng seeds were stratified for 90 days in a total of 12 different treatments and the dehiscence ratios were compared; drainage methods, drainage time, the ratio between ginseng seeds and sand, and etc. Seed stratification process was performed according to the guideline of ginseng GAP. One thousand ginseng seeds were used for each treatment. It was found that the average of dehiscence of the 12 treatments was 84.6 %. The highest dehiscence ratio (90.3 %) was observed in the seeds that were treated with water soaking, immediately followed by drainage. Higher ratio was also observed in the seeds that were soaked for 60 min, followed by drainage. Therefore, our findings indicate that ginseng seeds soaked in water less than 60 min could dehisce more efficiently than traditional method. Conclusion : Our study demonstrated that ginseng seeds that are subjected to water soaking and then drainage showed better ration of dehiscence. This method will eventually decrease the time and labor used for seed stratification.

Background : This study was conducted to determine the impact of temperature elevated and the effect of transplanting times based on climate change scenario on growth of 2-year-old korean ginseng (Panax ginseng C. A. Meyer.) in temperature gradient chambers (TGC). Methods and Results : As a plant materials, ‘Yunpoong’ was cultivated in TGC at ambient temperature(Amb), Amb+2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng was also transplanted on March 29, April 12 and 26 respectively. Investigation on characteristic of aerial parts were carried out on 28, 56, 84 and 112 days after transplanting and characteristic of roots were conducted on October 19. As transplanting time was faster and temperature was higher, the growth of aerial parts were increased. Compared with those of ginseng transplanted on March 29 with Amb, the root weight which tend to decrease depending on late transplanting time and high temperature decreased about 11.1%, 35.4% and 42.4% in Amb+ 2℃, Amb+4℃ and Amb+6℃ respectively. Ginseng transplanted on April 12 and 26 decreased about 20.9%, 33.9% respectively. Conclusion : Consequently, the more transplanting time extend, the more quantity increased in all temperature treatment. So, it is possible to increase in quantity to advance transplanting time although high temperature will be caused by the climate change.

Background : When ginseng seeds were gathered, the seeds were unripe. To grow immature embryo definitely, special treatment called dehiscence must be performed. Even though dehiscence is completed, most ginseng seeds are on enforced dormancy. The breaking seed dormancy is generally achieved using cold treatment. Also it is reported that gibberellin treatment can replace the treatment. It is very time consuming process in order to develop new ginseng cultivar because ginseng flowers after 3 years of growth. To shorten the ginseng breeding period, it is necessary to establish fast generation progress. Therefore, this study examined the possibility of breaking seed dormancy of ginseng using GA3 treatment and alternating temperature. Methods and Results : Seeds were obtained from local variety fruit which is not inbred. Gibberellin of 100 ppm was treated at seeds for 24 hours. Fixed cold condition was treated on both –2℃ and 2℃. Alternating cold condition was treated on 2℃ and then –2℃, finally 2℃. Fixed and alternating temperature was continued for 15, 30, 45, 60, 90 days that 15 days of alternating temperature is first 2℃ for 5days and then -2℃ for 5days, finally 2℃ for 5days. The other treatment periods such as 30, 45, 60, 90 days mean 10, 15, 20, 30 days respectively. Each of 48 seeds were sowed on tray in greenhouse at 3 replication. Experimental plot was completely randomized. Conclusion : Seeds untreated with GA3 were germinated little and there is no difference between 2℃ and –2℃. Alternating temperature until 60days made no difference with fixed temperature but germination rate increased up to 70.8% when seeds were treated for 90days. Germination of seeds treated with GA3 is much higher than untreated seeds especially combined with alternating temperature.

Background : In order to determine the effects of planting methods on root growth of ginseng varieties, two different methods, direct seed sowing and transplanting were compared in terms of their effects on different root growth characteristics. Methods and Results : Higher fresh root weight was observed in ginseng grown by direct seed sowing. Direct seed sowing of three cultivars (Sunhyang, Chungsun and K-1) resulted in higher yield, whereas no difference was observed in the yield of one cultivar (Chungsun). Gumpoong was highly tolerant to physiological stress, as it showed fewer symptoms of rusty and rough skin root diseases in both direct seed sowing and transplanting. The average main root length per total root length of ginseng grown by direct seed sowing was 33.6%, whereas that of ginseng grown by the average of those by transplanting was 22.4%. Other root growth characteristics, including root length, main root diameter, and number of side roots, improved when the direct seed sowing method was used. Conclusions : To our knowledge, this is the first study reporting the differences in root growth parameters of ginseng varieties grown by direct seed sowing or transplanting at the same planting density. Because of the advantages of direct sowing during ginseng planting, developing new varieties and improving cultivation methods are imperative.

Background : Excessively high concentration of sodium ion causednutrient deficiency and significantly decrease growth. This study was carried out to determine the limiting concentration range of sodium ion in the soil of ginseng field. Methods and Results : The growth of the ginseng cultivar Chunpoong reduced with increase in salinity, and the rate of growth reduction was higher in shoots than that of roots. Particularly, ginseng plants cultivated at high level of nitrate nitrogen or sodium may suffer delayed development and stunted growth. Chlorophyll damage occurred on the leaves of ginseng planted in relatively high levels (> 0.2 c㏖+/㎏) of sodium ion, as determined by the fluorescence reaction. The incidence of physiological disorder in ginseng cultivated at 249 sites was correlated with the concentration of sodium ion in the soils. About 74% of ginseng fields in which physiological disorders occurred had concentrations of sodium ion in soil greater than 0.2 c㏖+/㎏. In contrast, the concentration of sodium ions at 51 of 85 sites where no damage occurred was relatively (0.05 c㏖+/㎏- 0.15 c +/㎏). Conclusions : The concentration of sodium ion in soil of ginseng fields can be classified into three levels optimum (≤ 0.15), permissible allowance (0.15 - 0.2) and excessive (> 0.2).

Background : Correct identification of Panax species is important to ensure food quality, safety, authenticity and health for consumers. This paper describes a high resolution melting (HRM) analysis based method using internal transcribed spacer (ITS) and 5.8S ribosomal DNA barcoding regions as target (Bar-HRM) to obtain barcoding information for the major Panax species and to identify the origin of ginseng plant. Methods and Results : A PCR-based approach, Bar-HRM was developed to discriminate among Panax species. In this study, the ITS1, ITS2, and 5.8S rDNA genes were targeted for testing, since these have been identified as suitable genes for use in the identification of Panax species. The HRM analysis generated cluster patterns that were specific and sensitive enough to detect small sequence differences among the tested Panax species. Conclusion : The results of this study show that the HRM curve analysis of the ITS regions and 5.8S rDNA sequences is a simple, quick, and reproducible method. It can simultaneously identify three Panax species and screen for variants. Thus, ITS1HRM and 5.8SHRM primer sets can be used to distinguish among Panax species.

Background : Considerable time and effort is required to develop new Panax ginseng varieties. Ginseng breeders have been developing techniques to shorten the breeding cycle to resolve this problem. In this study, we investigated the effects of adding GA3 and alternating temperature (AT, 2℃→ −2℃ → 2℃) on breaking bud dormancy in the varieties (Chungsun and Sunun) of ginseng root. Methods and Results : The GA3 soaking treatment and AT were applied to one year old roots, which greatly accelerated the emergence of new buds. In one year old roots, new buds emerged from the 4th day post transplanting and after breaking dormancy with GA3 and AT treatments. The emergence of new buds was completed within two weeks. The rate of bud emergence for Chungsun was 60% - 98% over 15 - 60 days after the AT and GA3 treatments. The emergence rate of Sunun was 46% - 92%. Normal growth of the ginseng seedling was observed in spite of the early breaking of bud dormancy by combined GA3 and AT treatments. Conclusions : GA3 and AT treatments shortened the dormancy period and facilitated the stable emergence of ginseng seedlings. However, some plants suffered deformities and early sprouting owing to the combined GA3 and AT treatments. Early sprouting was free from dormancy after leaf fall from the of aerial part of the plant.

This paper is to evaluate the flexural characteristics of 180MPa Ultra High Performance Concrete and reinforcing steel. In this study, the bending test is performed to evaluate the flexural characteristics considering lap-splice length. The stability of the lap-splice length proposed the structural design codes are evaluated on load-displacement. The results confirmed that the ductility has increased when the lap-splice has increased.

This paper is to evaluate the flexural characteristics of 180MPa Ultra High Performance Concrete and reinforcing steel. In this study, the bending test is performed to evaluate the flexural characteristics considering cover depth. The stability of the cover depth proposed the structural design codes are evaluated on load-displacement. The results confirmed that the ductility has increased when the cover depth has increased.

본 연구에서는 죽산천 주변 지역에 대해 SWAT-MODFLOW 결합모형으로 암반층 지하수 양수에 따른 하천수 감소량을 모의하여 하천-관정 이격거리, 대수층 및 하천바닥층 수리특성 등과의 관계를 파악하고, 양수 위치에 따른 하천수 감소량을 공간적으로 표출하여 그 특징을 분석하였다. 양수정 위치에 따른 하천과의 이격거리, 투수량계수, 저류계수, 하천바닥층 수리전도성 등의 차이로 인해 지하수 양수량 대비 하천수 감소량 비율이 10∼90%의 범위를 나타내었으며, 투수량계수가 10 m2/day 보다 크거나 저류계수가 0.1보다 작은 경우 대부분 관정에서 하천수 감소율이 50%를 초과하는 것으로 분석되었다. 암반층에서 지하수를 양수할 경우 5년 동안 평균적으로 53.6%의 하천수 감소율을 나타내어 충적층 양수에 비해 12.9%만큼 덜 감소하는 것으로 분석되었다. 또한 죽산천 중하류부에서 양수 영향이 비교적 크게 나타나는 것으로 분석되었다.

본 연구에서는 죽산천 주변 지역에 대해 지하수 양수에 따른 하천수 감소 영향을 공간적으로 분석하였다. 하천 주변 500 m 이내에 위치한 지하수 관정 각각에 대해 지표수-지하수 결합모형 SWAT-MODFLOW를 이용하여 양수 후 하천수 감소량을 반복적으로 모의하였다. 모의 결과, 양수량 대비 하천수 감소율이 20～96%의 범위로 큰 차이를 보였으며, 특히, 하천과 관정간 이격거리가 100 m 이내, 수리확산계수가 500 m2/d 초과, 하천바닥층 수리전도성이 25 m/d를 초과한 경우에 양수량 대비 하천수 감소율이 60%를 넘어 양수 영향이 큰 것으로 분석되었다. 지하수 관정의 공간적인 위치에 따른 하천수 감소 영향을 정량적으로 쉽게 파악할 수 있도록 관정 위치별 하천수 감소량을 양수량 대비 퍼센트 값을 가지는 등치선 곡선으로 나타내었다. 죽산천 중하류구간 주변지역이 상류지역에 비해 지하수 양수로 인한 영향이 단기간에 크게 하천에 도달하였으며, 양수기간 5년 동안 평균적으로 약 66.7%의 하천수 감소율이 발생하는 것으로 분석되었다. 하천수량에 미치는 지하수 양수 영향을 공간적으로 표출함으로써 하천변 지하수 허가 관리에 있어 객관적인 정보로 활용할 수 있을 것이다.

본 연구에서는 한강유역을 대상으로 관측홍수량 자료의 불확실성이 홍수빈도분석 결과에 미치는 영향을 평가하고자 하였다. 이를 위해 한강유역 내의 17개 수위관측지점의 홍수량 자료를 이용하여, 지역홍수빈도분석을 수행한 결과인 지수홍수와 분위수를 중심으로 정량적인 평가를 수행하였다. 연구결과는 관측자료의 특성에 따라 3가지 경우로 분류하여 분석하였다. 첫 번째로 수위자료의 영향을 파악하기 위해 평창강 유역의 수위관측지점을 대상으로 지역홍수빈도분석 결과를 분석하면, 평균홍수량에 대한 오차는 0.240으로 평가되었다. 두 번째로 레이팅 적용에 따른 관측자료의 불확실성이 지역홍수빈도분석 결과에 미치는 영향을 분석하였다. 해당연도에 개발된 레이팅을 각각 적용한 결과와 가장 최근 개발된 레이팅을 적용한 결과를 분석해보면, 평균홍수량에 대한 오차는 평균 0.246으로 평가되었다. 마지막으로 인위적으로 유량이 조절된 댐하류의 통제된 흐름영역에서의 지역홍수빈도분석 결과를 유추하였다. 댐하류에서의 홍수량 거동은 댐운영에 의해 조절된 것으로 댐상류의 자연유역에서의 비유량 지역화 결과를 연장할 경우, 댐하류의 조절유역에서의 비유량 거동과 큰 차이를 나타내었다.