• Korean Journal of Medicinal Crop Science
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• v.9 no.3
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• pp.232-237
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• 2001

This study was carried out to know the effect of light intensity, temperature and $CO_2$ concentration on photosynthesis and transpiration in yacon(Polymnia sonchifolia Poepp.& Endl.). Light compensation point was ${58\;{\mu}mol\;m^{-2}\;s^{-1}}$and light saturation point was ${1708\;{\mu}mol\;m^{-2}\;s^{-1}}$. Transpiration rate was increased to about 4 mmol${m^{-2}\;s^{-1}}$ with increasing of light intensity to ${2193\;{\mu}mol\;m^{-2}\;s^{-1}}$. The optimum temperature for photosynthesis was ${24^{\circ}C}$ in air. Photosynthesis was gradually reduced as transpiration rate increased from 4 to 8 mmol ${m^{-2}\;s^{-1}}$ in different air temperature. $CO_2$ compensation point was 63 vpm and $CO_2$ saturation point was 1155 vpm and light saturation point was enhanced with increasing of $CO_2$ concentration from 350 vpm to 1300 vpm.

• Proceedings of the Korean Society of Crop Science Conference
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• 1997.10a
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• pp.82-83
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• 1997

• Proceedings of the Korean Society of Crop Science Conference
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• 1997.10a
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• pp.84-85
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• 1997

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.79-82
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• 2000

Tuberous root of yacon (Polymnia sonchifolia Poeppig ＆ Endlicher) has not starch, and its brix degree changes during the curing. Therefore its chemical composition changes were investigated according to different curing conditions. Tuberous root contained 87.1% moisture at harvesting, that was decreased to 84.1-86.0% at 30 days after curing in different curing conditions. Brix degree was increased from 5.7 to 14.2-15.8% at 30 days after curing in comparison to at harvesting. Free sugars were detected from tuberous root in yacon by HPLC; that were fructose, glucose and sucrose. Fructose contents were increased from 0.09 to 1.04-1.79% during 30 days in five curing conditions. Glucose contents were shown to increase from 0.03 to 1.04-1.37 %. Sucrose contents were shown to increase from 0.04 to 0.13-0.43%. Tuberous root contained fructose, glucose and sucrose in order of amount that were highest in single-polyethylene film covered green house. Sucrose was little as comparison with fructose and glucose. Fructose and glucose were increased to 16.7 and 40.7 times, respectively, but sucrose was increased little about 6.8 times.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.101-107
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• 2000

The explants of yacon (Polymnia sonchifolia Poeppig & Endlicher) were cultured to invest th8e dedifferentiation condition, and formative callus from leaf was cultured to find the regeneration and micro-crown bud formation. Basal MS medium was more effective to form callus than 1/2 MS and B$_{5}$ medium. Calli formations from leaf, petiole and lateral bud were more effective on MS medium supplemented with 1.0, 2.0 mg/L 2,4-D and 0.2, 0.4 mg/L kinetin or BA than 1.0, 2.0 mg/L NAA and 0.2, 0.4 mg/L kinetin or BA. Formative callus from leaf was proliferated about 70% on medium supplemented with 1.0 mg/L BA. When callus was proliferated, 63% regeneration rate was shown on medium supplemented with 1.0, 2.0 mg/L BA in case of subculture for 3~4 months but was not shown on medium supplemented with 1.0, 2.0 mg/L kinetin. Micro-crown bud formed as addition of BA at 3~4 months after callus culture and then was obtained many at 5~6 months, it was most formed about 82% on medium supplemented with 5 mg/L BA. Rate of micro-crown bud formation was increased as more over 5 mg/L BA concentration, when this time, however, shoot had thick leaves and short internodes, and then withered before long, Micro-crown bud was formed about 88.0% on medium supplemented with 5% sucrose, that was more increased 28% than with 3% sucrose. The buds of crown bud between harvested in field and formed in vitro were difference only in size, but both were similar in shape according to histological view.

• Journal of Life Science
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• v.20 no.1
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• pp.40-48
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• 2010

This study was carried out to investigate the physicochemical and functional properties of Yacon (Polymnia Sonchifolia) powder. The proximate composition of Yacon powder as a dry matter basis was 3.53% moisture content, 1.13% crude protein, 0.40% crude fat, 0.79% crude ash, 1.63% dietary fiber and 92.52% carbohydrate. The major free sugars were identified as fructose and glucose. Analysing total amino acids, 18 kinds of components were isolated from Yacon powder. The essential amino acid contained in Yacon powder accounted for 28.40% of total amino acid, while the non-essential amino acid accounted for 73.61%. Analysing total fatty acids, only 2 kinds - palmitic acid and lauric acid - were detected. Oxalic acid was the major organic acid. The contents of vitamin A, vitamin C and vitamin E were 0.057 mg%, 0.670 mg% and 0.001 mg%, respectively. The mineral contents of Yacon powder were in the order of Zn

• Food Science and Preservation
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• v.9 no.1
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• pp.61-66
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• 2002

Chemical composition of fresh and dried leaves and stems and fresh and cured tubers of bacon (Polymnia sonchifolia) was investigated. The moisture content of fresh leaves, stems, and tubers was 83.38, 92.30 and 89.52%, and there of dried leaves and stems were 18.08 and 27.97% and that of cured tubers was 27.97%. The content of lipid, protein, soluble solid, ascorbic acids chlorophyll and tannin was higher in leaves of yacon than in stems of that. In fresh and cured yacon, the content of protein were 0.04% both of them, of lipid was 0.31 and 0.54%; of ash, 0.40 and 0.42%; of ascorbic acids 2.77 and 2.87 mg/100 g. The major minerals of leaves, stem, and tubers of bacon were P, K, and Mg. The major free sugars of leaves, stems and tubers of bacon were glucose and fructose and after curing all free sugars of tubers of bacon were increased. The most abundant free amino acid was isoleucine in the leaves, stem, and tubers of bacon. The content of beta-carotene was 9.01 $\mu\textrm{g}$/100g in fresh leaves and 107.87 $\mu\textrm{g}$/100 g in dried leaves, and 0.40 $\mu\textrm{g}$/100 g in fresh tubers of bacon and 055 $\mu\textrm{g}$/100 g in cured tubers.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.434-435
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• 2006

• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.151-152
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• 1998

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.274-278
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• 1996

This study was conducted to examine the dry matter production and leaf photosynthesis under different fertilizer application in Yacon(Polymnia sonchifolia)plants. Under field conditions, dry matter production of stable mature application plot(S-1) was much larger than non-treated control plot(CTL), but bulb dry weight of 10kg nitrogen application plot per 10a (N-10) was not differentiated from CTL. The maximum photosynthetic rates increased in Yacon plants grown at S-1 while in the rates of CTL reduced under glasshouse in the same treated pot condition. The optimum temperature for the highly photosynthetic rates is about $34{\pm}3^{\circ}C$, and the rates did decrease by stomatal resistance below 28℃. The estimated light saturation point was $1200{\mu}mol{\cdot}m^{-2}s^1$. The results of this study indicate that soil conditions were highly related to dry matter production and leaf photosynthesis rate in Yacon plants.