• Proceedings of the Korean Society of Crop Science Conference
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• 1996.10a
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• pp.60-61
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• 1996

• 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.

• Korean Journal of Medicinal Crop Science
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• v.1 no.1
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• pp.28-37
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• 1993

The low seed propagation is one of the problem needed a lot of seed tuber for the propagation in yam. Therefore this experiment was carried out to understand the possiblility of seed tuber propagation by tissue culture of yam. In-vitro stem node of yam was cultured by concentration treatments of 1/2, 1/4 and 1/8 with MS medium additted with each concentration levels of IAA, NAA, IBA, kinetin and BA. Acorrding to the Iower concentration than MS medium, length of shoots was promoted, leaf emergence shoots and rooting shoots were increased at 1/8 MS medium during the culturing period of stem node in yam. Fixed IBA and kinetin under the concentration of MS mdeium was inhibited severely by the heigh concentration additted with lAA $1mg\;/\;{\ell}\;and\;NAA\;4mg\;/\;{\ell}$. But fixed IBA $5mg\;/\;{\el}l\;and\;kinetin\;2mg\;/\;{\ell}$ with concentration of 1/8MS medium was remarkably promoted leaf emergence shoots and rooting shoots by $1mg\;/\;{\ell}$ of additted lAA and NAA. Percentage of induced shoots was increased by combination treatments of lAA. $1.5mg\;/\;{\ell}\;and\;kinetin\;2mg\;/\;{\ell}$, also leaf emergence shoots and rooting shoots were promoted by combination treatments of lAA $1.5mg\;/\;{\ell}\;and\;kinetin\;2mg\;/\;{\ell}$.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.266-272
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• 2009

The annual productions of yam and its aerial bulbils are estimated to 5,000 and 2,500 ton, respectively. But the majority of bulbils had been discarded without specific use. In this study, methanol extract and its organic solvent fractions were prepared from bulbils of Dioscorea batatas Decne, and their antimicrobial, antithrombin, and antioxidant activities were evaluated, respectively. The methanol extract contained 58.98% of water-soluble materials as like yam's extract. But the bulbils's extract contained 12-folds of total polyphenol and 3.4-folds of total flavonoids compared than yam's extract, respectively. For antimicrobial activity the hexane and ethyl acetate fraction showed strong antibacterial activity at $500{\mu}g/disc$ concentration against gram-negative and gram-positive bacteria. Antifungal activity was not observed in any fractions. Strong antithrombin activity was found in the hexane fractions. At 4.8 mg/mL concentration thrombin time (TT) was over 300 sec, which is 4-folds extended than the TT of yam. In a while, the ethyl acetate fraction showed strong DPPH scavenging activity ($IC_{50}$ of $38.1{\mu}g/mL$), SOD-like activity and reducing power, which are comparable to vitamin C or BHT. Our results suggest that the bulbils of yam as yam tuber have useful bio-activities, such as antibacterial, antithrombosis, and antioxidant activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.250-254
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• 2011

The study was carried out to evaluate the affect of proton beam radiation on production of bulbil and tuber including change of endogenous gibberellins, of Dioscorea opposita Thunb. The yield of bulbils and tubers from non- and irradiated D. opposita Thunb at doses of 5, 10, 15 and 20 Gy were determined. Endogenous gibberellins were also quantified by GC/MS analysis. D. opposita tubers irradiated at 15 Gy produced higher bulbil production than non-irradiated plants. Enlarged bulbil (above size diameter 4 mm) was significantly increased at 15 Gy. Bioactive endogenous $GA_4$ was dominant in bulbils and tubers irradiated with proton beam rather than $GA_1$. Major gibberellins biosynthetic pathways in bulbils and tubers of D. opposita plants were non C-13 hydroxylation route. From the results of this study, 15 Gy proton beam radiation was suggested as an optimal dose that can produce high amounts of bulbil for mass production of D. opposita plant.

• Plant Resources
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• v.3 no.3
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• pp.211-218
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• 2000

Intraspecific genetic relationship of 19 variation types of the Yam (Dioscorea alata) classified by their external morphological characteristics such as leaf and tuber shape were assessed by DNA using random and specific primer. Twenty two out of 113 primers (100 random[10-mer] primers, two 15 mer [M13 core sequence, and (GGAT)$_4$ sequence]) had been used in PCR-amplification. Only 12 primers, however, were success in DNA amplification in all of the analyzed plants, resulting in 93 randomly and specifically amplified DNA fragments. The analyzed taxa showed very high polymorphisms(69 bands, 71.0 %), allowing individual taxon to be identified based on DNA fingerprinting. Monomorphic bands among total amplified DNA bands of each primer was low under the 50%. Similarity indices between accessions were computed from PCR(polymerase chain reaction) data, and genetic relationships among intraspecific variations were closely related at the levels ranging from 0.66 to 0.90. These DNA data were not matched well with those of morphological characters since they were divided into two major groups at the similarity coefficient value of 0.70. Therefore, Grouping of species into variation types by mainly morphological charactistics was suggested unreasonable.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.55-64
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• 2002

This study was carried out to determine agronomic and genetic characteristics of the production process in tropical yams(Dioscorea alata 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 50-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 40-days and continued to the 90-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.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.48-69
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• 2001

A lot of clones of the genus Dioscorea have been introduced from some tropical and subtropical regions since 1997. In 33 clones of water yams (Dioscorea alata L.), some morphological characteristics were investigated at the field. Variation ranges of the total weight and tuber number per stump were within the ranges from 90 to 2,147 g with an average of 610 g ; and 1.3-4.7 with an average of 2.8, respectively. The color tones observed on the tuber-flesh were sorted into 3 color-categories, i.e., white, pale brown and pale purple, and those on leaves were sorted into 3 color-categories, i.e., green, heavy green and purplish green. Intraspecific genetic relationship of 19 variation types of the Yam classified by their external morphological characteristics such as leaf and tuber shape was assessed by DNA using random and specific primers. Twenty two out of 113 primers (100 random[10-mer] primers, two 15 mer [M13 core sequence, and (GGAT)4 sequence]) had been used in PCR-amplification. Only 12 primers, however, were successful in DNA amplification in all of the analyzed plants, resulting in 93 randomly and specifically amplified DNA fragments. The analyzed taxa showed very high polymorphisms(69 bands, 71.0%), allowing individual taxon to be identified based on DNA fingerprinting. Monomorphic bands among total amplified DNA bands of each primer was low under the 50%. Similarity indices between accessions were computed from PCR(polymerase chain reaction) data, and genetic relationships among intraspecific variations were closely related at the levels ranging from 0.66 to 0.90.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.45-54
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• 2002

A lot of clones of the genus Dioscorea species have been introduced from some tropical and subtropical regions since 1997. The aim of this study was to determine characteristics of the production process in yams(Dioscorea spp). By utilizing 51clones of water yams(Dioscorea spp), some morphological characteristics were investigated at the field. Intraspecific genetic relationship of 51 variation types of the Yam classified by their external morphological characteristics such as leaf and tuber shape were assessed by DNA using random and specific primers. D. Alata and D. opposita were showed different relationship between yield and the growth of their aboveground parts. This suggests that even in the same species there were differences in yield volume and translocation of assimilation products, depending on the types. D. alata were distinguished from others Dioscorea species at 62% level in AFLP analysis. Also in principal component analysis, D. alata were showed the class from II to V.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.33-37
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• 1998

Browning index rised rapidly within 15 hrs to 83% of total browning in Jang - ma (Dioscorea batatas Decne) tissues at $40^{\circ}C$ while 37% in Dan - ma. Therefore, the degree of browning process of Jang - ma was faster than that of Dan - ma. Browning in Jang - ma was inhibited by treatments of NaCl which showed 48 and 39% inhibition, respectively, after 48 hrs of incubation. Also the treatment of $80^{\circ}C$ heating showed excellent inhibition within 24 hrs. In the case of Dan - ma, browning process was inhibited by treatments of 1 and 0.5M NaCl and $70^{\circ}C$ heating, which showed 43, 26 and 23% inhibition, respectively, after 48 hrs of incubation.