• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.27-27
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• 2021

Yacon [Samallanthus sonchifolius (Poepp. & Endl.) H. Robinson], a member of Compositae plants, has sweet taste and crisp texture. Unlike other Andean root crops such as potato and sweet potato, the cultivation area of yacon has increased recently, since it is known to have large content of fructooligosaccharides (FOS). Since there are no yacon varieties bred in Korea, we have been trying to create new genetic resources using gamma-ray. The optimal gamma-ray dosage for mutation breeding in yacon was investigated. Crown bud and green bud of yacon were exposed to doses of gamma rays from 20 Gy to 80 Gy, and subsequently planted in a greenhouse. After 50 days of sowing, the survival rates and growth decreased rapidly at doses above 40 Gy, while all of crown bud individuals died above 60 Gy. The median lethal dose (LD50) of crown bud and green bud was 22.4 and 36.6 Gy, and the median reduction doses (RD50) for plant height, fresh weights, and tuberous root weight were 20-40 Gy, respectively. A dose of 20-40 Gy was found to be optimal for mutation breeding in yacon. Considering the growth factors, the optimum doses were determined to be within the range of 20-40 Gy for the selection of useful mutant lines. M2-M3 mutant lines were obtained from 20-60 Gy gamma-ray-irradiated M1 plants through clonal propagation. These mutant lines will be used for the development of a new variety of yacon plant with high FOS and no crack tuberous root.

• Molecules and Cells
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• v.21 no.1
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• pp.63-75
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• 2006

The 5′-region of Potato virus X (PVX) RNA, which contains an AC-rich, single-stranded region and stem-loop structure 1 (SL1), affects RNA replication and assembly. Using Systemic Evolution of Ligands by EXponential enrichment (SELEX) and the electrophoretic mobility shift assay, we demonstrate that SL1 interacts specifically with tobacco protoplast protein extracts (S100). The 36 nucleotides that correspond to the top region of SL1, which comprises stem C, loop C, stem D, and the tetra loop (TL), were randomized and bound to the S100. Remarkably, the wild-type (wt) sequence was selected in the second round, and the number of wt sequences increased as selection proceeded. All of the selected clones from the fifth round contained the wt sequence. Secondary structure predictions (mFOLD) of the recovered sequences revealed relatively stable stem-loop structures that resembled SL1, although the nucleotide sequences therein were different. Moreover, many of the clones selected in the fourth round conserved the TL and C-C mismatch, which suggests the importance of these elements in host protein binding. The SELEX clone that closely resembled the wt SL1 structure with the TL and C-C mismatch was able to replicate and cause systemic symptoms in plants, while most of the other winners replicated poorly only on inoculated leaves. The RNA replication level on protoplasts was also similarly affected. Taken together, these results indicate that the SL1 of PVX interacts with host protein(s) that play important roles related to virus replication.

• Horticultural Science & Technology
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• v.29 no.2
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• pp.144-150
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• 2011

This study was conducted to investigate the nutrient components and physicochemical properties of general ('Superior') and colored potato. Proximate composition, reducing sugar, free sugars, free amino acids, organic acids, minerals were analyzed, and Hunter color values were measured in the study. 'Rose' and 'Blue' (colored potatoes) contained high levels of reducing sugar, and total free sugar content was greatly different according to varieties. Glutamic acid, arginine and ${\gamma}$-aminobutyric acid were detected to be the three major amino acids in colored potato, and the major organic acids of general potato were oxalic acid, tartaric acid, malic acid and citric acid. All potato contained high level of potassium, calcium and magnesium. The Hunter 'L' value was the highest in 'Jaseo'; Hunter 'a' value was high in 'Blue' and 'Jasim'; Hunter 'b' value was the highest in 'Haryoung'. Overall, colored potato had higher amount of nutrients and physicochemical properties than 'Superior'. Therefore, colored potatoes are expected to be highly valuable items for the development and applications of a functional food. In addition, these results will provide fundamental data for improving sitological value, breeding of new cultivar and promoting of roughage usage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.85-91
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• 1994

This experiment was conducted to obtain the basic information of the major chemical components for breeding high quality varieties of sweet potatoes [Ipomoea batatas (L) Lamk]. Six recommended varieties were cultivated at the experimental plots of Hwasung and Suwon in 1992. Starch value. glucose, fructose, maltose, and sucrose content were analyzed with time intervals during storage period. Starch value of Shinyulmi was the highest among six varieties in both locations. Glucose and fructose contents were appeared wide variations in varieties and locations. Shinyulmi showed the highest maltose content and Yulmi had the highest sucrose content in two locations. Total sugar contents were higher in Shinyulmi and Yulmi. Starch value, glucose, fructose, maltose, and sucrose content were stable during storage period, however these were differed between locations.

• The Korean Journal of Pesticide Science
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• v.5 no.2
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• pp.45-50
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• 2001

In recent, non virus-induced mosaic symptoms(NVMS) on potato leaves were observed in the seed potato fields, and its incidence rate was $5{\sim}20%$ nationwide. It made difficult to rogue out virus-infected plants, and caused much arguments between seed potato production farmers and seed potato inspectors. The objectives of these experiments were to find out the causes of NVMS, and also to induce mosaic symptom(phytotoxicity) on potato plants by treatment of several herbicides. No significant correlations were found between incidence rates of NVMS and values from soil analyses; soil pH, soil EC, organic matter content, and contents of inorganic constituents($P_2O_5,\;NO_3$, Ca, Mg, K) in the soil around the potato planted. The examinations by ELISA, virus indicator plants, and TEM showed that NVMS on potato leaves was not caused by the viruses infection. But, the use of herbicides could induced the NVMS on potato leaves. The incidence rates of potato treated with pendimethalin linuron of 400 mL/10 a, pendimethalin of 200 mL/10 a, pendimethalin.oxadiazon of 300 mL/10 a, and control were 61.1%, 47.2%, 19.4%, and 1.4%, respectively. Based on these results, we confirmed that the treatment of pendimethalin alone and in mixture with other herbicides were the reason of NVMS on potato leaves. The yields among test plots were similar except dicamba treated plot, which decreased by about 23% compared to control plot. When their progenies harvested in 1999 were planted in the following season, no symptoms of mosaic were observed.

• Journal of Plant Biotechnology
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• v.47 no.2
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• pp.141-149
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• 2020

Solanum hougasii, one of the wild Solanum species, has been widely used in potato breeding since it exhibits excellent resistance to diverse important pathogens. S. hougasii can be directly crossed with the cultivated tetraploid potato (S. tuberosum) owing to its EBN (Endosperm Balanced Number) value of 4, which is same as that of S. tuberosum although it is an allohexaploid. In this study, the complete chloroplast genome sequence of S. hougasii was obtained by next-generation sequencing technology, and compared with that of the chloroplast genome of seven other Solanum species to identify S. hougasii-specific PCR markers. The length of the complete chloroplast genome of S. hougasii was 155,549 bp. The structural organization of the chloroplast genome in S. hougasii was found to be similar to that of seven other Solanum species studied. Phylogenetic analysis of S. hougasii with ten other Solanaceae family members revealed that S. hougasii was most closely related to S. stoloniferum, followed by S. berthaultii, and S. tuberosum. Additional comparison of the chloroplast genome sequence with that of five other Solanum species revealed five InDels and 43 SNPs specific to S. hougasii. Based on these SNPs, four PCR-based markers were developed for the differentiation of S. hougasii from other Solanum species. The results obtained in this study will aid in exploring the evolutionary and breeding aspects of Solanum species.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.603-612
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• 2012

In order to select potato clones for making cold chip, this study analyzed the glucose content, acrylamide content, and the correlation between the two properties after harvest, $4^{\circ}C$ and $8^{\circ}C$ low-temperature storage, and $20^{\circ}C$ heating treatment of 47 breeding clones and control cultivars 'Atlantic', 'Sumi', and 'Gui Valley'. In all of the control cultivars and 47 clones, glucose content was below 0.25% and acrylamide content was below 1000 ppb just after harvest, but after $4^{\circ}C$ low-temperature storage both the glucose content and acrylamide content increased rapidly and only 4 clones H7, H13, H16, and H40 showed a level below 500 ppb. In $8^{\circ}C$ low-temperature storage as well both contents increased, but the increase was relatively smaller than that in $4^{\circ}C$ low-temperature storage. In addition, $20^{\circ}C$ heating treatment decreased both contents. In the results of analyzing the correlation between glucose content and acrylamide content at low-temperature storage, a positive correlation was observed. In conclusion, clones H7, H13, H16, and H40 showing low glucose content even at low-temperature treatment were found to contain less acrylamide and therefore they were selected as potato clones suitable for making cold chip.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.333-345
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• 2017

The potato tuber is known as a rich source of essential nutrients, used throughout the world. Although potato-breeding programs share some priorities, the major objective is to increase the genetic potential for yield through breeding or to eliminate hazards that reduce yield. Glycoalkaloids, which are considered a serious hazard to human health, accumulate naturally in potatoes during growth, harvesting, transportation, and storage. Here, we used the AMMI (additive main effects and multiplicative interaction) and GGE (Genotype main effect and genotype by environment interaction) biplot model, to evaluate tuber yield stability and glycoalkaloid content in six potato cultivars across three locations during 2012/2013. The environment on tuber yield had the greatest effect and accounted for 33.0% of the total sum squares; genotypes accounted for 3.8% and $G{\times}E$ interaction accounted for 11.1% which is the nest highest contribution. Conversely, the genotype on glycoalkaloid had the greatest effect and accounted for 82.4% of the total sum squares), whereas environment and $G{\times}E$ effects on this trait accounted for only 0.4% and 3.7%, respectively. Furthermore, potato genotype 'Superior', which covers most of the cultivated area, exhibited high yield performance with stability. 'Goun', which showed lower glycoalkaloid content, was the most suitable and desirable genotype. Results showed that, while tuber yield was more affected by the environment, glycoalkaloid content was more dependent on genotype. Further, the use of the AMMI and GGE biplot model generated more interactive visuals, facilitated the identification of superior genotypes, and suggested decisions on a variety of recommendations for specific environments.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.165-171
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• 2004

A total of 62 isolates of Bipolaris cactivora causing cactus stem rots were isolated from major cactus-growing areas in Korea. Colony morphology of the isolates on potato-dextrose agar was differentiated into aerial (CA) and non-aerial mycelial types (CB). CA had profound aerial mycelium with grayish brown (CA-l), light brownish (CA-2), and brownish (CA-3) pigmentations; respectively, while CB had dark brownish pigmentations. CA had conidia of less dark pigmentation and acute terminal end. CB had darker and more round-end conidia. Twenty-eight amplified fragments were produced by polymerase chain reaction (PCR) with a set of 2 random primers. The sizes of amplified DNA fragments ranged approximately from 0.1 to 2.3 kb. The isolates were classified into 2 major genomic DNA random amplified polymorphic DNA (RAPD) groups at the genomic similarity of 97.7％ and 95.1％, respectively. Cluster analysis of genetic similarity among the isolates generated a dendrogram that clearly separated all isolates into SA or SB. This result suggests that there may be two morphotypes of B. cactivora in Korea that may differ in their genetic constitutes.

• Journal of the Korean Home Economics Association
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• v.19 no.4
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• pp.9-15
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• 1981

damages of cotton cloth and characteristics of fabroid degradation were studied by Chaetomium globosum and Aspergillus niger which presupposed as powerful erosive fungi to cellulose fiber by means of tensile strength. The results obtained are as follows: 1. the growth(rate) of fungi in malt extract agar was superior to potato agar for two weeks. 2. Chaetomium globosum showed mostly severe damage t the cotton cloth in malt extract agar media at pH 4.5. 3. Tensile strength was reduced with time by Aspergillus niger-coenzyme and Chaetomium globosum-coenzyme reaction. In comparison with Chaetomium globosum and Aspergillus niger, the former weaken tensile strength about 15.8% and the latter enfeebled 10.0% after 124 hours. 4. after 30 days the breeding of fungi in pH 4.5 malt extract agar media, critical damage of cotton cloth was observe, I. e., 92.4% damage by chaetomium globosum and 74.9% lose by aspergillus nige respectively.