• Research in Plant Disease
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• v.10 no.2
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• pp.135-137
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• 2004

It was conducted to select the resistant potato cultivars to common scab, to replace the existing susceptible cv Dejima in Jeju island conditions both 1997 and 2001. Among cultivars, cvs Jemchip, Alpa, Atlantic and Jopung were more resistant than others in the field with both low and high incidence of the disease. Also among the existing cultivars grown in Korea, cvs Superior, Jopung and Chubaek were resistant, expecially in terms of production of marketable potatoes.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.455-458
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• 2001

To screen potato clones with high resistance to hollow heart (HH) and internal brown spot (IBS), field conditions were set up to induce high frequencies of physiological disorders in 'Atlantic' potato through various treatments of mulching, periodic shadings, and plant growth regulators such as trinexapac-ethyl (Tr-E) and dicloprop-triethanol mine (DTA). IBS occurrence was as high as 67.5% in the field plot mulched with transparent film and shaded for 10 days beginning at 80 days after planting. The highest level of HH was 22.9% in the plot mulched with transparent film and shaded for 10 days beginning at 60 days after planting. Very high level of IBS (66.3%) also occurred in the plot treated with 1500 mg/L of Tr-E 40 days after planting, while HH occurred by 21.3% in the plot treated with 1000 mg/L of DTA 70 days after planting. In the plots which were treated with 1,500 mg/L of Tr-E after 40 days of planting and 1000 mg/L of DTA after 70 days of planting, 'Superior' (moderately highly resistant) and 'Atlantic' (very susceptible) could be clearly distinguished to be resistant and susceptible. High occurrence condition set up in this study could be applied for the potato breeding program to screen potato clones with high resistance to HH and IBS.

• The Plant Pathology Journal
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• v.19 no.6
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• pp.284-287
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• 2003

Potato tubers with scab lesions were found in several regions of Gangwon province in Korea during disease surveys in 2000 and 2001. The lesions appeared as shallow scabs with torn and raised skin around the periphery of the lesion. Sometimes the lesions expanded on tuber surface and formed hollowed-out areas. The causal organism was identified as Spongospora subterranea based on morphological characteristics using light and electron microscope. Ten cultivars of potato were evaluated to select resistant cultivars against powdery scab. Among the 10 cultivars, Jowon, Superior, and Atlantic were resistant, while Sephody, Gawon, and Irish Cobbler were susceptible to powdery scab. In the pathogenicity test, typical symptoms of powdery scab were formed on potato tubers, and galls developed on root hairs. This is the first report of powdery scab of potato caused by S. subterranea in Korea.

• Journal of Plant Biotechnology
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• v.7 no.3
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• pp.183-186
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• 2005

Cryopreservation has been recognized as a practical and efficient tool for the long-term storage of vegetatively propagated plants. This study was conducted to investigate the effects of slow-freezing techniques on the cryopreservation of potato. In vitro plantlets of the potato genotypes of 'Atlantic', 'Superior’, 'Namseo', 'J138', and 'CTO5-5' were cold acclimated, and the excised axillary buds were precultured, osmoprotected, exposed to plant vitrification solution, frozen slowly to $-40^{\circ}C$ and then rapidly plunged into liquid nitrogen, thawed and finally plated on the regeneration medium. It was found that the higher the sucrose concentrations in the subculture medium of donor plantlets, the higher the survival rates of shoot tips after cryopreservation, and the highest survival (20%) was observed in the medium added with 0.25 M sucrose. As for the effect of cooling, $0.3^{\circ}C/min$ cooling speed showed the highest survival (25%). Different varieties showed different responses over different cryopreservation treatments. Survival rate was increased by slow-freezing technique method as compared with that of the basic cryopreservation method of vitrification alone in the diverse potato genotypes. Leaf and tuber morphologies of potatoes regenerated after cryopreservation using slow freezing technique were similar to those derived from the in vitro stock plantlets.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.437-442
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• 1992

In order to develop color of potato chip made from Superior variety and Irish Cobbler variety, various conditions on NaCl and $CaCl_2$ contents, heat treatment and soaking time were applied. The content of reducing sugar decreased by $30{\sim}40%$ in blanching without NaCl and $CaCl_2$. In NaCl soaking case, reducing sugar content decreased by $15{\sim}30%$, however, partial colorization was appeared that the sample turned to brown. In the sample that were soaking in NaCl solution and heat treated, reduction of reducing sugar was 40% and desirable time for heat treatment was 5 min and 7 min. In the sample treated $CaCl_2$ solution, reduction of reducing sugar was $25{\sim}30%$ and then color was not acceptable. In the sample soaking $CaCl_2$ solution and heat treated, reducing sugar content rapidly by 50% and the color development was the most ideal.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.39-39
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• 2017

In Asia, sweet potato (Ipomoea batatas) is a very important crop for starch production. Approximately 74.3% of the total sweet potato production quantity is produced in Asia (FAO, 2014) and China is the largest producer of sweet potato. Post-harvest management is particularly important because it is difficult to maintain the quality as well as quantity of sweet potatoes. Despite the importance of post-harvest management, researches on sweet potato have been focused on production-related study such as breeding of new variety, improved techniques of cultivation, so there is limited research on storage after harvest. Curing is a normal practice after sweet potato harvest to promote wound healing and extend postharvest storage life. In Korea, harvested sweet potatoes are usually cured for 4 to 7 days at $30-33^{\circ}C$ and 80-95% relative humidity within one week. Since the optimum storage temperature of sweet potato is regarded as $15-20^{\circ}C$, additional facilities and costs are required to raise the temperature for curing. However, the majority of small farmers do not have the capacity to provide additional facilities and costs. This study was initiated to suggest a new curing method to accelerate the wound healing by applying chemical oxidation to the wound surface of sweet potato. Oxidative stress is known to play an important role in the synthesis of secondary metabolites including lignin. In addition, chemical oxidation can be applied to prevent spoilage caused by microorganisms. Powerful gaseous oxidant with excellent penetration ability and superior sterilization effect was selected for this study. Lignification, weight loss, and spoilage rate of artificially wounded sweet potatoes were investigated after oxidant fumigation. There were clear differences in morphological analysis such as lignification pattern, lignin deposition color, and continuity of lignified cell layers between oxidant-fumigated sweet potatoes and control. These results show that gaseous oxidant can be used to supplement or replace the curing practice, to improve shelf-life as well as curing cost reduction.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.515-520
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• 2001

To observe the stimulating effect of low dose ${\gamma}$ radiation on the dormancy breaking and growth, microtubers of two potato cultivars (Solanum tuberosum L. cv. Dejima and cv. Superior) were irradiated at the dose of 0.5-30 Gy. Though it varied with cultivars and storage duration, sprouting rate, plant growth and tuber yield were promoted by 2-8 Gy irradiation in microtuber of 'Dejima' stored at low temperature. On the other hand, in microtuber of 'Superior', sprouting rate was promoted by 2 and 4 Gy irradiation, and the growth and tuber yield by 4 Gy irradiation. These results suggest that low dose of ${\gamma}$ radiation could have stimulating effects on the dormancy breaking of microtuber and potato growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.167-170
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• 2000

This study was conducted to investigate the changes of potato growth and soil properties in highland mounding-soil. Experimental plot was designed with control, chemical improvement and zeolite+chemical improvement plots. Mounding-soil was low in organic matter and phosphate contents, and that soil texture was loamy sand soil. The growth and yield of potato were highest in the zeolite treatment plot. Yield of that increased by 3.7% than control plot. Increasing ratios of potato tubers decreased at 60-70 days after planting. Increasing ratio of zeolite plot was higher or than other treatment plots. After harvesting, the contents of soil organic matter increased by 12-125%, and those of phosphate were by 29-73% respectively. The manurial value of fused and superphosphate was higher than that of potassium chloride.

• Applied Biological Chemistry
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• v.29 no.4
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• pp.352-358
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• 1986

The relationship between weight reduction and rehydration of dehydrofrozen potato was determined. At initial stage of dehydration sliced potato lost moisture rapidly. After drying for 2 hours weight reduction of sliced potato was 56% for Superior var., and 55% for Irish Cobbler. The empirical drying equations were obtained as follows: ${\frac{M-M_e}{M_o-M_e}}={\exp}(-0.4487\;{\theta}^{1.2328})$ and ${\frac{M-M_e}{M_o-M_e}}={\exp}\;(-0.4951\;{\theta}^{1.1949})$ for Irish Cobbler and Superior, respectively, where $M_o$, $M_e$, and M are dry base moisture content(%) of initial, equilibrium and at time ${\theta}$ in hour, respectively. With the decrease of weight above 50%, the rehydration rate decreased sharply and the color index L value also decreased while a and b increased. Lightness of dehydrofrozen potato decreased slightly and rehydration rate remained constant during storage at $-18^{\circ}C$. The sulfite treatment led to increase of L value and decrease of a and b values.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.299-305
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• 2007

Oxidative stress is a major damaging factor for plants exposed to environmental stresses. Previously, we have generated transgenic potato (cv. Superior) plants expressing both CuZnSOD and APX genes in chloroplast under the control of an oxidative stress-inducible SWPA2 promoter (referred to as SSA plants) and selected the transgenic potato plant lines with tolerance against methyl viologen (MV)-mediated oxidative stress. When leaf discs of SSA plants were subjected to $3{\mu}M$ methyl viologen (MV), they showed approximately 40% less damage than non-transgenic (NT) plants. SSA plantlets were treated with $0.3{\mu}M$ MV stress, SSA plants also exhibited reduced damage in root growth. When 350 MV was sprayed onto the whole plants, SSA plants showed a significant reduction in visible damage, which was approximately 75% less damage than leaves of NT plants. These plants will be used for further analysis of tolerance to environmental stresses, such as high temperature and salt stress. These results suggest that transgenic potato (cv. Superior) plants would be a useful plant crop for commercial cultivation under unfavorable growth conditions.