• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.281-285
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• 2003

For storage periods of tubers in Chinese yam, the levels of $\textrm{GA}_{44}$ and $\textrm{GA}_{20}$ was constant, meanwhile both $\textrm{GA}_{53}$ and $\textrm{GA}_{19}$ level were always higher than that of $\textrm{GA}_{44}$ and $\textrm{GA}_{20}$ㆍ $\textrm{GA}_9$ content as precursor of $\textrm{GA}_4$ was not changed during storage. $\textrm{GA}_{24}$ content was low to below 0.2 ng for 90 days after storage, $\textrm{GA}_{36}$ content as precursor of $\textrm{GA}_4$ like $\textrm{GA}_9$ was about 6-8 fold higher than that of $\textrm{GA}_9$ during storage. GA contents of the two gibberellin biosynthetic pathways were gradually increased when storage periods were progressed. Bioactive GA$_1$ content as the GA members of an early C-13 hydroxylation was always constant, and its content was very low as below 0.1ng per dry weight, meanwhile, bioactive $\textrm{GA}_4$ content as the GA members of non C-13 hydroxylation was drastically increased, also, its content was highest at 90 days after storage, and then decreased at 120 days after storage. Consequently, we suggest that $\textrm{GA}_4$ may be involved in controlling tuber sprouting in Chinese yam.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11b
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• pp.38-39
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• 2002

• Applied Biological Chemistry
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• v.37 no.6
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• pp.509-515
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• 1994

Using the lipids extracted from Korean yam(Dioscorea) tubers, D. batatas, D. aimadoimo and D. japonica, fractionation and identification of lipid components and their fatty acid compositions were analysed. Lipid contents determined by Folch's method in D. batatas, D. aimadoimo and D. japonica were 11.0 mg/g, 11.4 mg/g and 6.6 mg/g, respectively. Lipids extracted were fractionated into neutral lipid, glycolipid and phospholipid by silicic acid column chromatography. The content of neutral lipid was over about 60% in lipid. Neutral lipid was composed of sterol ester, triglyceride, 1,3-diglyceride, 1,2-diglyceride and monoglyceride. Main constituents of glycolipid were acylsterylglycoside, monogalactosyldiglyceride, sterylglycoside, digalactosyldiglyceride and sulfolipid, and phospholipid contained phosphatidylethanolamine, phosphatidylcholine and phosphatidylinositol. The fatty acids of the total lipid and its three lipid fractions were analyzed by GC. The major fatty acids were palmitic and linoleic acids. Content of the saturated fatty acids was less than that of the unsaturated fatty acids.

• Korean Journal of Plant Resources
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• v.20 no.2
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• pp.99-103
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• 2007

Tuber yield and content of general component and diosgenin which is a main bioactive property were investigated in order to determine the growth characteristics of round typed yam (Dungeon-ma, Dioscorea opposita L.) and the potential of artificial culture at Suwon, Korea. Sprouting rates of segmented small tubers such as 3, 5, 7, 9, and 12g were respectively 60.3, 80.5, 85.3, 98.6 and 99.3% when they were investigated 30 days after planting. Segmented small tubers of 3, 5, 7, 9, and 12g enlarged respectively to 66, 87, 98, 120, and 140g in the green-house cultivation. Segmented small tubers of 3, 7, 12, 18, and 23g enlarged respectively to 35.2, 124.7, 142.7, 174.8, and 200,7g in the open-air field cultivation.

• Journal of Practical Agriculture & Fisheries Research
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• v.7 no.1
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• pp.55-63
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• 2005

Tuber yield and content of general component and diosgenin which is a main bioactive property were investigated in order to determine the growth characteristics of round typed yam(Dungeun-ma, Dioscorea opposita L.) and the potential of artificial culture at Suwon, Korea. Sprouting rates of segmented small tubers such as 3, 5, 7, 9, and 12g were respectively 60.3, 80.5, 85.3, 98.6 and 99.3% when they were investigated 30 days after planting. Segmented small tubers of 3, 5, 7, 9, and 12g enlarged respectively to 66, 87, 98, 120, and 140g in the green-house cultivation. Segmented small tubers of 3, 7, 12, 18, and 23g enlarged respectively to 35.2, 124.7, 142.7, 174.8, and 200,7g in the open-air field cultivation.

• Preventive Nutrition and Food Science
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• v.18 no.4
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• pp.249-255
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• 2013

Yam (Dioscorea) has long been used as foods and folk medicine with the approved positive effects for health promotion. Although consumption of yam products is increasing for health promotion, reports for the metal contamination in commercial yam powder products to protect the consumers are lacking. In this study, we aimed to assess whether the commercial yam powder products were heavy metal contaminated or not using the yam products from six commercial products from various places in South Korea. The contents of heavy metals (Cd, Cr, As, Pb, Ni, and Sn) in yam powder products were measured and compared to national and international food standard levels. Also, the metal contamination was monitored during the food manufacturing steps. The study results showed that the contents of heavy metals (Cd, Cr, As, and Pb) in yam powder products are similar to those in national 'roots and tubers' as well as in various crops. In comparison to three international standard levels (EU, Codex and Korea), Cd content in yam powder products was lower but Pb content was 5 times higher. Also, Pb, Ni, and Sn may have the potential to be contaminated during food manufacturing steps. In conclusion, the level of heavy metals (Cd, Cr, As, Ni, and Sn) except Pb is considered relatively safe on comparison to national and international food standard levels.

• Mycobiology
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• v.36 no.4
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• pp.217-221
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• 2008

During 2007 survey of post-harvest diseases of yam performed in May and June, severe tuber loss caused by blue mold was observed in Iksan, Cheonbuk Province. Two species of Penicillium were isolated from the infected tubers. Based on $\beta$-tubulin gene sequence analysis, and cultural and morphological characteristics, the isolates were identified as Penicillium sclerotigenum and P. polonicum. P. sclerotigenum, which is a novel to Korea, is presently described and illustrated.

• Korean Journal of Medicinal Crop Science
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• v.7 no.3
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• pp.167-171
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• 1999

This experiment was conducted to determine effects of trenching depth on characteristics and yield of tubers in Chinese yam (Dioscorea opposita Thunb). Self-propelled trencher, ‘NF-827H’ produced by KAWABE company, was used for trenching. When trenched, tuber's length and weight were longer and heavier, tuber's shape was better, and marketable tuber yield was remarkably increased than those of conventional plowing and soil preparation by a tractor. The size and yield of tubers were greatly enhanced by trenching in long-tuber variety than that in short-tuber variety. The depth of trenching is recommended to be more than 60cm for short-tuber variety and more than 80cm for long-tuber variety considering the size, shape and yield of the tllbers.

• Korean Journal of Plant Resources
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• v.15 no.3
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• pp.285-292
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• 2002

This study was carried out to determine agronomic and genetic characteristics of the production process in tropical yams(Dioscorea atata L.). To make clear the possibility of cultivation of tropical yams in the Suwon area, the growth of the aboveground parts and the enlargement of tuber of Dioscorea alata, were investigated. The aboveground parts of the plants whose sprouted mother tuber were planted in late April were grown slowly until the 70-days after planting and grown rapidly after. from about 150-days after plantation, total length of vines slowly decreased due to the burning of the branch vines of lower modes. With regard to the branching progressed to 4th for the solo yam and to 6th for purple yam. The secondary branches tended to grow better. When the formation of daughter tubers was observed at the 50-days after planting, their enlargement was very slow. The rapid growth of tubers began at the 140-days and continued to the 190-days. General components such as protein, fiber, and lipid were higher in D. opposita rather than in D. alata. Hardness of D. alata was 2696.2 while that of D. opposita was 4946.9. Lightness of D. alata was 73.99, being higher than that of D. opposita.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.58-63
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• 1997

The experiment was done to clarify the effect of keeping material and storage temperature on weight and quality of Chinese yam (Dioscorea opposita) tuber. After the yam tubers were placed into the plastic boxes filled with different keeping materials [polyethylene (PE) film, hull, soil, sand, vermiculite], they were stored under different storage temperature(room, cold) from Oct. 15 to Mar. 15 when all the characters related to the tubers were measured. Soil or PE film as keeping materials was the lowest sound tuber rate when stored at room or cold temperature, respectively, while vermiculite was the highest in both storage temperature. When PE film and vermiculite in both storage temperatures were used as keeping materials, tuber weight were less reduced than the others. Brightness of chromaticity and moisture content were lower in room temperature storage than in cold temperature storage although the characteristics related to marketability were not affected by storage temperature. PE film had greater brightness and value 'a' of chromaticity but lower its 'b' value in the latter temperature than in the former temperature. Vermiculite, however, did the reverse result in comparison with PE film.