• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.91-97
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• 1994

To improve the productivity of peroxidase (POD) of cell line SP-47 derived from cell suspension cultures of sweet potato (Ipomoea batatas (L) Lam.cv White Star), we optimized culture conditions including the composition and concentration of plant growth regulators and carbon source, and the cell inoculum size. When one g (fr wt) of cells was inoculated into 50 mL TL medium supplemented with l mg/L 2,4-D and 30g/L sucrose in 300 mL Erlenmeyer flask at 25$^{\circ}C$ in the dark (100rpm), the POD activity per g cell dry wt was maximized to be about 6,800 units after 25 days of subculture, which was about 30 times higher than that of intact roots of horseradish plants grown in the greenhouse, but the cell growth was maximum after 15 days of subculture. The protein content per g cell dry wt maintained almost plateau and after 25 days of subculture decreased as culture Proceeded further whereas the POD specific activity (unit/mg protein) was about two times higher after subculture and continuously increased from 12 days to the end of cultures (40 days). The POD isozyme patterns showed almost the same regardless of cell growth stage, but some acidic isozymes were slightly increased after 25 days of subculture. These results indicate that POD activity in suspension cultures of sweet potato is closely associated with cell growth and stresses derived from cell culture renditions and medium depletion. Due to its high POD activity the SPL47cell line seems to be suitable for the mass production of POD.

• Journal of Plant Biotechnology
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• v.3 no.2
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• pp.59-66
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• 2001

Photoautotrophic micropropagation systems do not include sugar in the culture media. This characteristic provides advantages to scale up the micropropagation systems comparing photomixotrophic micropropagation systems. A closed, large-scale photoautotrophic micro-propagation for transplant production system has been developed at Chiba University, Japan. New concepts and technologies were adapted to produce high quality transplants at minimum usage of resources, and as scheduled. Newly developed software for production management was used to enhance the efficiency of the transplant production system. Currently, virus-free transplants of sweetpotato (Ipomoea batatas (L.) Lam.) are vegetatively propagated and produced under sterilized conditions in this system. This system can also be used for production of transplants of any other species including horticultural and woody plants with a minimum of modification.

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.571-578
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• 2015

This study was carried out to investigate the quality characteristics of bread containing sweetpotato (Ipomoea batatas (L.) Lam) leaf powder (0, 2, 3, 5, and 7% of the total flour). We found that the addition of sweetpotato leaf powder decreased the pH of the dough, whereas the total titratable acidity increased and the specific volume and baking loss of bread were decreased. However, the moisture content of the bread did not show any significant differences. The L and a values of the bread inner crumb were decreased by the addition of sweetpotato leaf powder, however, the b value was increased. The 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activity, total polyphenol, lutein and ${\beta}-carotene$ contents were increased significantly by the addition of sweetpotato leaf powder. The taste, color, flavor, chewiness and overall acceptability of bread containing 2~3% sweetpotato leaf powder were better than those of the controls. We found that the sample group with 2~3% sweetpotato leaf powder is the optimum content for making bread.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.305-311
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• 2013

Effects of cultivation methods on quality characteristics, pasting characteristics, chemical components, and antioxidant activities of sweet potatoes (Ipomoea batatas (L.) Lam) were determined. The Brix degree, hunter color value, pasting characteristics, moisture, protein, and mineral contents of the sweet potatoes showed significant differences from cultivation methods. The total polyphenol and flavonoid contents of the methanolic extracts of the sweet potato's pericarp were higher than sweet potato's sarcocarp. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the sweet potato's pericarp on the conventional culture and successful cropped hairy vetch culture was 776.38 and 715.20 mg TE/100 g sample. The 2,2'-azino-bis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) radical scavenging activity of the sweet potato's pericarp on the conventional culture and successful cropped hairy vetch culture was 708.03 and 708.58 mg TE/100 g sample. Generally, there was a difference in antioxidant compound content and radical scavenging activity on the methanolic extract of sweet potato with cultivation methods.

• The Korean Journal of Food And Nutrition
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• v.36 no.4
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• pp.327-333
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• 2023

This study investigated the antioxidant characteristics of sweet potato according to different plant parts and drying methods. The sweet potato plant parts were divided into root tubers, stems, stalks, leaves, and tips, and the drying methods were freeze-drying and hot air drying. Total polyphenol and flavonoid contents and radical scavenging activity of the sweet potato plant parts were significantly different depending on the plant parts and drying methods. The total polyphenol content of freeze-dried sweet potato leaves and tips were 52.76 and 46.19 mg chlorogenic acid equivalents/g sample, and the total flavonoid contents were 222.47 and 214.12 mg quercetin equivalents/g sample, respectively, and decreased with hot air drying. DPPH radical scavenging activity was higher in freeze-drying than hot air drying and was significantly different depending on the plant parts. The ABTS radical scavenging activity of freeze-dried sweet potato leaves and tips were 43.48 and 44.68 mg Trolox equivalents/g sample, respectively, and decreased with hot air drying. Therefore, additional studies on the functionality of using by-products from sweet potato cultivation are needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.402-406
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• 2003

Greenhouse and laboratory studies were conducted to determine the allelopathic potentials of extracts or residues from sweet potato (Ipomoea batatas L. (Lam). The extracts applied on filter paper in a Petri dish bioassay significantly inhibited root growth of alfalfa. Aqueous leachates at 40g dry tissue $\textrm{L}^{-1}$ (g $\textrm{L}^{-1}$) from leaves showed the highest inhibition against alfalfa, and followed by stems and roots. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. The effect of residue incorporation into soil on seedling growth of com, soybean, barnyard grass and eclipta was examined in the greenhouse, and results showed that the leaf residues at 200g $\textrm{kg}^{-1}$ by plant parts inhibited shoot dry and root dry weights of test plants by 60-80%. By means of HPLC, causative allelopathic substances present in plant parts of sweet potato "Sinyulmi" were identified as coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid, and chlorogenic acid. Total content of these compounds for leaves extracts were detected as the greatest amount in EtOAc fraction, especially trans-cinnamic acid was the greatest component. These results suggest that sweet potato plants have herbicidal potentials, and that their activities exhibit differently depending on plant parts.ant parts.

• Journal of Plant Biotechnology
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• v.29 no.3
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• pp.189-192
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• 2002

An efficient plant regeneration system of major cultivars of sweetpotato (Ipomoea batatas (L.) Lam.) in Korea via somatic embryogenesis was established. Embryogenic calli were formed from shoot apical meristems of sweetpotato cultivars when cultured on LS medium supplemented with 1 mg/L auxin (2,4-D, picloram, dicamba). Among three kinds of auxin, 1 mg/L 2,4-D showed the highest embryogenic calli induction rate. After 4 weeks of cultures on LS medium supplemented with 1 mg/L 2,4-D, embryogenic calli induction rates of Sinhwangmi, Zami, Yulmi, and White Star were 86%, 78%, 76%, and 80%, respectively. Upon transfer onto LS basal medium, most of somatic embryos developed into plantlets. Regenerated plantlets were transplanted to potting soil and grown to mature plants in a greenhouse.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.1-8
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• 2020

The influence of growth regulators (NAA and BA) and sucrose concentrations (0, 3, 5, 7, 9%) on in vitro rapid-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] was investigated with single-node or shoot-tip culture of two cultivars ('Matnami' and 'Shinhwangmi'). The survival rate and growth of shoot-tip explant was also investigated under the presence or absence of light (blue and red LED = 7:3, 150±5 μmol·m^-2·s^-1 PPFD) during minimal-growth in vitro conservation at 15℃. Vine length, vine diameter, fresh weight and dry weight were enhanced without callusing of explant in the MS medium supplemented with 0.2-0.5 mg·L^-1 BA. The growth of single-node and shoot-tip explants were significantly enhanced with the increase of vine length, number of leaf, number of root, fresh weight, and dry weight in the solid medium containing 5% sucrose and 0.2 mg·L^-1 BA. Vine elongation of shoot-tip explants were highest in the liquid medium containing 3% sucrose than the solid medium. The survival rate of minimal-growth in vitro conservation was 100% in 5 months under the presence of light (LED, 150±5 μmol·m^-2·s^-1 PPFD) at 15℃, but the explants in dark condition died in 3 months. The light was absolutely necessary for the in vitro conservation under minimal-growth conditions of virus-free sweet potato plantlets at 15℃, and the high density of explants (10 plantlets per Petri Dish) was increased the efficiency of mass conservation.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.490-498
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• 2017

The in vitro growth of virus-free sweet potato [Ipomoea batatas (L.) Lam.] plantlets was investigated under different light sources: fluorescent lamp (control); red (660 nm), blue (460 nm), white light-emitting diodes (LED), and two mixtures of blue and red LED (R:B = 8:2, and 7:3). Single node explants (10 mm) of three cultivars ('Matnami', 'Shincheonmi', and 'Yeonhwangmi') were cultured on Murashige and Skoog medium supplemented with $0.2mg{\cdot}L^{-1}$ 6-benzyladenine for 4 weeks. Explants were exposed to $150{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux at a distance of 20 cm, constant temperature of $25^{\circ}C$, and under 16/8-h (day/night) photoperiod. Using the same method, the in vitro growth of 10 cultivars under red LED was also compared. After 3 weeks, vine length was highest in plantlets cultured under red LED, and lowest in plantlets cultured under blue LED. Fresh and dry weights were also greatest in plantlets cultured under red LED. Compared to the control, vine thickness was significantly higher in plantlets grown under white LED and the 7:3 R:B LED mixture. Significant differences were observed among the 10 cultivars grown under red LED. 'Matnami', 'Shincheonmi', and 'Shinhwangmi' all had excellent vine lengths, and fresh and dry weights. Compared to the control, vine elongation of sweet potato plantlets was most effective under red LED, and culture duration was about 1 week shorter.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.686-693
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• 2012

To develop a technique for mass-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] plant using nutrient film technique (NFT), the growth characteristics of 4 cultivars as affected by nutrient solution composition and cutting size were investigated. 72 cells (35 mL/cell) plug trays filled with vermiculite and perlite (1:1, v/v) were used. Vine length, fresh and dry weights of virus-free plants were the greatest in the nutrient solution recommended by National Horticultural Research Station in Japan, followed by that recommended by National Institute of Horticultural & Herbal Science in Korea, and Yamazaki's nutrient solution for lettuce. The growth of uppershoot cuttings was the best among 4 subsections of cutting. Vine length, and fresh and dry weights increased in the longer cutting treatments, and were better in 'Shinzami' and 'Yeonhwangmi' than those in 'Mannami' and 'Shincheonmi'. Vine diameter and length of the longest root were not significantly affected by the cutting size and cutting source. The growth characteristics of the single node cutting were not significantly different from those in 2-node cutting. The efficiency of rapid mass-propagation could be promoted with single node cuttings and uppershoot cuttings grown in NFT system.