The purpose of this study was to confirm the possibility of using Korean purple yam (Dioscorea alata) as proximate composition, material, and antioxidant activity. In the proximate composition of the freeze-dried purple yam powder, the carbohydrate content was the highest at 86.67%, and in minerals, potassium showed the highest content at 1,765.69 mg/100 g. To study the antioxidant activity of purple yam, distilled water and 70% ethanol were used as extraction solvents. The total polyphenol, total flavonoid, and total anthocyanin contents were 1.3~1.6 times higher in 70% ethanol extract, than in the distilled water extract. As a result of ORAC, DPPH and ABTS radical scavenging activity, SOD activity, and reducing power, the 70% ethanol extract showed higher antioxidant activity than the distilled water extract in all results. As a result of freeze-drying purple yam and measuring antioxidant activity by extraction solvents, it is concluded that purple yam can contribute to the food industry as a natural antioxidant and health functional material.

Background : Unlike Dioscorea japonica or Dioscore opposita, Dioscore alata is a high-temperature crop mainly cultivated in Africa and subtropical regions. Due to recent climate change, its cultivation area is expanding in Korea. In 2016, the Institute for Bioresource Research clarified optimal harvesting stage to increase its tuber yield and ensure safe storability. Methods and Results : As the seed-tubers for this study, Dioscorea alata tubers were cut into a size of 50 g, disinfected with lime powder, dentated on the seed bed with electrothermal wire installed on March 20th, and then planted on the main field on April 15th. The planting distance was 120 ㎝ in width, where the furrows of 90 ㎝ were cladded with black vinyl, in two rows with a column spacing of 25 ㎝. The amounts of applied fertilizers were 2,000 ㎏ compost, 34 ㎏ N2, 28 ㎏ P2O6, and 28 ㎏ K2O. The compost and P2O5 were used in full, where as N2 and K2O were used as original fertilizer 14 (10 ㎏) and additional fertilizer 20 (18 ㎏), respectively. The crop was harvested in six times from September 20th to November 9th, in an interval of 10 days. While harvesting, the ground fresh weight yield and underground tuber yield were investigated. The underground tuber yield was 836, 1,744 and 2,975 ㎏ low at the early harvests on September 20th, 30th, and October 10th, respectively, while it was 3,622, 3,828, 3,818 ㎏ high on October 20th, 30th, and November 9th, respectively. The ground fresh weight yield remained the same. To clarify tuber storability by harvest time, they were stored at 15℃after harvest, and then healthy and corrupt tubers were studied on March 23th. The corruption ratio by harvest time was highest at 39.1% and 29.3% on October 30th and November 9th, respectively, when frost and low temperature damaged harvest. It was 59.0% and 42.8% at the early harvests on September 20th and 30th, respectively. The corruption ratio was lowest on October 20th and October 10th at 29.3% and 39.1%, respectively. Conclusion : Ford. Dioscore alata cultivation, Korea presents a premature and disadvantageous environment with lower temperature and pre-harvest frost at the time of planting. After raising seeding on an electrically heated hot bed, the optimal harvesting stage should be from planting in the middle of April where temperature rises above 1 5℃ to harvesting in the period October 10th - 20th so as to achieve the maximum tuber yield and high storability.

Background : study of long yam and short yam (Dioscorea. opposita) are cultivated in temperate regions but tropical yam (Dioscorea alata) are mainly grown in Africa and sub-tropical regions cultivated crops. Recent tropical yam cultivation area of Korea increased but lack the proper cultivation techniques to climate warming. This study was conducted to elucidate the effect of the timely harvest on Tropical yam at 2015 in Institute of Bioresources Research, GBARES. Methods and Results : Tuber of tropical yam were cut as 40 g, and dust-coating sterilized with lime. Seedlings were grown in heating wire installed seed bed from 11. March to 16. May. Experimental field were fertilized 2,000 kg compost, 34 kg N2, 28 kg P2O5, and 28 kg K2O. All amount of compost and P2O5 treated as basal fertilizer. N2 and K2O treated 14 and 10 kg of basal fertilizer, and 20 and 18 kg of additional fertilizer, respectively. Tillage, covering black PE film with 60×25 cm spacing holes on 120 cm row were conducted. Emergence days from 6. April to 18 May until 28 days to 36 days but 15. June and 9. June were each 19 and 7 days. Dry weigh in early stage due to seedling date, while seedling date according from 6. April to 18. May had no difference. seedling date was not effective on total number of tuber but number of marketable tuber (over 200 g). Marketable tuber number of seedling date according to 20. April was increased 35~132% as 4,028 number per 10 a. And tuber with 20. April was 13~73 g heavier. Tuber yield and marketable tuber yield of seedling date as affected by 20. April were respectively 2,518 and 1,273 kg per 10 a compared to 6. April and from 4. May to 15. June as 1,743~2,457 kg and 484~1,027 kg. Conclusion : Tropical yam is low temperature in the cultivation of Korea but also adverse environmental conditions. Frost is not mature enough off before harvesting. Yam had significant increased marketable tuber (over 200 g) yield due to seedling in mid-April Requires cultivation technology.

Background : Yam absorbs nutrition and water through water absorptive root generated from head of rhizome. Round-shaped yam (RSY, Dioscorea opposita) and tropical round-shaped yam (TRSY, Dioscorea alata)are more sensitive to drought because of shorter head of rhizome and shallower root compared to long yam or short yam. This study was conducted to elucidate the effect of irrigation on RSY and TRSY yam at 205 in Institute of Bioresources Research, GBARES. Methods and Results : Tuber of RSY and TRSY were cut as 40 g, and dust-coating sterilized with lime. Seedlings were grown in heating wire installed seed bed from 25. March to 16. April. Experimental field were fertilized 2,000 kg compost, 34 kg N2, 28 kg P2O5, and 28 kg K2O. All amount of compost and P2O5 treated as basal fertilizer. N2 and K2O treated 14 and 10 kg of basal fertilizer, and 20 and 18 kg of additional fertilizer, respectively. Tillage, installation of drop-watering tapes, and covering black PE film with 60×25 cm spacing holes on 120 cm row were conducted. 20 L per m2 was irrigated 7 days interval except rainy day from middle of May to late of September. RSY had high emergence rate in early stage due to irrigation, while TRSY had no difference. Irrigation was not effective on total number of tuber but number of marketable tuber (over 200 g). Marketable tuber yield of RSY according to irrigation was increased 89% as 1,147 kg per 10 a. And tuber with irrigation was 73 g heavier. Tuber yield and marketable tuber yield of TRSY as affected by irrigation were respectively 2,611 and 1,715 kg per 10 a compared to control, 1,462 and 428 kg. And irrigated tuber was 66 g heavier. Conclusion : TRSY had more effective on irrigation than RSY. Both of yam had significant increased marketable tuber yield due to irrigation. Therefore RSY and TRSY are necessarily irrigated because of those absorptive characteristics, short head of tuber and shallow root.

국내에서 생산되는 아열대 마의 저장성을 향상 시키고자 저장기간 동안 발생되는 주요 병원균을 분리동정하여 병원성을 확인하고, 큐어링 처리 조건별로 부패억제 효과를 조사하였다. 아열대 마 저장중 부패를 일으키는 주요 병원균은 Penicillium sclerotigenum와 Penicillium polonicum으로 확인되었고 P. sclerotigenum이 좀더 병원성이 강하였다. 수확도중 절단된 부위는 큐어링 하기전 반드시 매끈하게 잘라야만 정상적인 유상조직층이 형성되었다. 괴근 절단면을 상대습도 95%에서 3일간 23℃, 28℃ 그리고 33℃로 큐어링 처리하여 유상조직층을 관찰한 결과, 23℃ 처리구는 괴근육과 표피층의 색농도가 비슷하여 확인이 어려운 반면, 28℃ 이상 처리구는 뚜렷하게 관찰되었다. 0.5 mm 이상의 유상조직 형성율도 28℃ 처리에서 93%, 33℃ 처리에서 96%로 양호하였으나 23℃처리구에서는 52%로 낮게 나타났다. 상온에서 바람이나 햇볕을 이용하는 관행적인 큐어링 처리구는 유상조직층 형성이 미미하였다. 저장고안의 상대습도에 따른 병원균의 감염은 습도가 40%와 60%로 유지되었을 경우 감염비율이 낮았고 큐어링 처리간에도 차이가 없었다. 저장고내 습도가 80%인 경우 모든 처리구에서 균이 급격히 증식하였다. 저장온도 16℃에서 상대습도 60%를 유지하여 180일 후 처리별로 부패율을 조사한 결과, 절단된 괴근을 햇볕이나 바람에 의해 큐어링된 관행적인 처리구는 43%였으나, 28℃ 이상에서 큐어링하여 유상조직층이 형성된 괴근은 18% 이하로 나타났다. 건전한 괴근도 관행처리구에서 25%의 부패율을 보인 반면 28℃ 이상에서 큐어링된 괴근은 10% 이하로 나타났다. 중량감소율도 관행처리구에 비하여 강제 처리구가 중량이 1~6%정도 덜 감소하였다.

도입 마(Dioscorea alate L.) 계통 중 품질이 우수하고 이 용 가치가 기대되는 열대산 마(D. alata)를 우리나라에서 재배 시 그 가능성과 제 기관의 생육특성을 밝히기 위하여 실시하였다 D. alata. 및 D. opposita의 생육패턴 및 수량성을 비교 도입 재배 가능성을 시험하였다. 1. 4월 하순에 정식한 마의 지상부는 70일까지는 완만한 생육을 보였으나, 그후에 급격히 생장하여, 200일 이후 지상부의 하부가 낙엽지며 감소하였다. 생육은 D. atara, 단마 순이였다. 2. 도입마(D. alate)의 형성은 정식 50일 정도에서 일어났으나, 그 후 비대생장이 늦어서 150일 이후에 급격 히 비대하였다. 3. D. alata(도입마)의 일반성분은 D. opposita(단가) 보다 단백질, 섬유, 지방의 함량이 낮았다. 4. D. alata의 경도를 보면 2696.2로 D. opposita 4946.9 보다 약 2배정도 낮고, 색도 중 명도(L)는 D. alata가 73.99으로 D. opposite 보다 높았다.

본 연구는 조직배양을 이용하여 도입된 다수확 우량마 (Dioscorea alata L. ) 의 대량증식을 위한 배양체계 를 확립 하였다. 식물생장조절제 (NAA) 및 sucrose를 첨가한 MS배지에서 마의 무균경단편을 배양하면 경단편에 괴경이 형성되었다. 이 괴경 형성에 미치는 식물생장조절제의 종류와 농도, Sucrose의 농도 및 광조건에 대한 영향을 조사한 결과, 마의 괴경 형성은 식물 생장조절제의 첨가에 의해 촉진되어서 괴경형성율은 NAA 1mg/l을 첨가한 배지에서 최고율이었다. Sucrose 농도를 높일수록 형성률이 상승되어 6%처리구에서 최고에 달했다. 괴경 형성에 가장 큰 영향을 미치는 것은 광조건으로 암흑조건의 형성율은 명조건 보다 크게 상회하였다. 그리고 암조건에서는 액아부위가 맹아하지 않고 무균 경단편에 괴경만이 형성 되었다. 이상의 결과에서 마의 괴경 형성에 최적의 배양조건은 NAA 1mg/l, surcrose 6%를 침 가한 1/2MS 배지에 무균경단편을 치상하여 25℃ 암흑조건하에 배양한 것이었다.