• Research in Plant Disease
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• v.9 no.3
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• pp.137-144
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• 2003

This study was conducted to clarify developmental characteristics of scab in potato fields in Jeju island, Korea from 1995 to 1999. Occurrence of potato scab increased with repeated cultivaton of potato and high soil pH in the fields. Incidence of the disease was high as 54.8％ in the repeatedly cultivated potato fields but relatively low as 20.8~26.3% in the non-cultivated fields and in the fields where barley and Chinese cabbage were formerly cultivated. A total of 66 isolates were obtained from the diseased patato tubers and identified as Streptomyces scabies, S.turgidiscabies and S. acidiscabies. The isolation frequency of each Streptomyces species was 37.7%, 14.8% and 18.0%, respectively. The optimum temperature for mycelial growth of the Streptomyces spp. was $28~30^{\circ}C$, and the optimum pH for that 6~7.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.414-419
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• 1991

Polyphenol oxidase from Jerusalem artichoke(Helianthus tuberosus L.) tubers was partially purified by precipitation with ammonium sulfate, followed by gel filtration on Sephadex G-100. The enzyme showed maximal activity at pH 6.5 and $4^{\circ}C$. Kinetic studies indicated $K_{m}$ value of 3 mM for catechol and activation energy of 72.6 kcal/mole. As for substrate specificity of polyphenol oxidase the enzyme showed high affinity towards diphenol compounds, but not towards monophenols. The enzamatic browning was completely inhibited at 1 mM concentration of L-ascorbic acid, sodium hydrosulfite and L-cystein(HCl). The activity of polyphenol oxidase in 0.1 M potassium phosphate buffer(pH 6.5) was fairly stable for a week at $4^{\circ}C$, while it decreased remarkably at $25^{\circ}C$.

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.89-93
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• 2000

This experiment was conducted to investigate the effects of soil texture on agronomic characteristics and tuber yield in chinese yam (Dioscorea opposita Thunb). Tuber length and weight was greater and tuber shape was much better in sandy loam and loam soil than in sandy or clay loam soil. In loam and sandy loam soil, fresh tuber yield was increased by $21{\sim}27%$ in short-tuber type and 6% in long-tuber type, and large tubers yield (above 260g) was increased by $45{\sim}55%$ in short-tuber type and $20{\sim}22%$ in long-tuber type compared to those in sandy soil. There was no differences in large tuber yield at the 5% level of significance between loam and sandy loam soil. Malformation of tuber with bifurcation was extremely increased in sandy soil, and tuber diameter of long-tuber type was decreased in clay loam soil compared to those of the other soil texture.

• The Korean Journal of Food And Nutrition
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• v.22 no.2
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• pp.223-228
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• 2009

The principal objective of this study was to determine the available components in different varieties of Discorea spp. The Discorea spp. samples were divided into three groups by variety. The three groups were divided into Jangma(D. batatas Decaisne), Danma(D. japonica Decaisne), and Doonggunma(D. opposita Thumb), and then assessed with regard to the content of proximate compositions, minerals, sugars, crude saponin, and diosgenin. No substantial differences were noted to exist among samples in terms of carbohydrate and crude protein contents. The crude lipid contents were detected in the following order : Danma(D. japonica Decaisne, $0.71{\pm}0.15%$) > Jangma(D. batatas Decaisne, $0.65{\pm}10.12%$) > Doonggunma (D. opposita Thumb, $0.49{\pm}0.10%$). The Danma(D. japonica Decaisne) samples were determined to harbor the highest K($2.07{\pm}0.91%$), Ca($0.21{\pm}0.12%$), Fe($110.7{\pm}0.0$ mg/kg), Mn($20.6{\pm}3.4$ mg/kg) and Zn($31.2{\pm}3.9$ mg/kg) contents among all tested samples. The predominant sugar components in all samples were mannose($70.7{\pm}1.3{\sim}80.5{\pm}1.5%$), glucose($18.2{\pm}1.2{\sim}28.3{\pm}2.5%$) and sucrose($60.3{\pm}3.7{\sim}83.6{\pm}6.5%$). The crude saponin and diosgenin contents for Jangma(D. batatas Decaisne), Danma(D. japonica Decaisne) and Doonggunma(D. opposita Thumb) varieties were : $1.7{\pm}0.4%$, $3.9{\pm}0.8%$ and $3.2{\pm}0.7%$, and $13.59{\pm}1.74$ mg/g, $14.25{\pm}1.60$ mg/g and $18.00{\pm}1.92$ mg/g, respectively.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.354-361
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• 2011

In order to product dry goods of Gastrodiae Rhizoma with high quality, tubers were treated with various dry methods such as cutting, drying methods and steaming. In cutting than no cutting, they were shown shorter drying hours and lower drying yield. Drying hours in freeze drying was shorter than those of hot air and far-infrared ray. Total polyphenol content was higher in cutting than no cutting. According to steaming, it was increased in freeze drying but decreased rapidly in the other dry methods. Among all treatments, hot air dry treatment with cutting and no steaming had the highest total polyphenol content. Gastrodin and 4-hydroxybenzyl alcohol contents generally were similar or higher in cutting than no cutting. By steaming, gastrodin content in freeze drying was decreased but 4-hydroxybenzyl alcohol content was increased. But hot-air and infrared ray dry, they were shown opposite results. Gastrodin and 4-hydroxybenzyl alcohol contents showed opposite reaction to each other and were shown various response by dry methods.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.45-49
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• 2004

Verticillium tenerum was detected from the samples of potato (Solanum tuberosum L.) and pumpkin (Cucurbita maxima Duch.) in Korea. The samples on which this species was detected were potato tubers collected from Pyungchang and Gimjae, and fruits and seeds of pumpkin from Yeonchon in 2003. The conidiophores of the fungus produced mainly three to five phialides in verticil. The phialides were narrow, flask-shaped, only very slightly swollen at the base, and taper subulately to a narrow neck. They were hyaline, $10{\sim}26{\times}2{\sim}5\;{\mu}m$. The conidia were formed in slimy heads, and were oval to ellipsoidal, pale reddish-brown, $2.5{\sim}7.5{\times}2{\sim}4\;{\mu}m$. The colony on the substrata was unique, showing brick-red color. This is the first report on the distribution of Verticillium tenerum in Korea.

• Journal of Bio-Environment Control
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• v.8 no.1
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• pp.30-35
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• 1999

The purpose of this study was to evaluate the effect of temporary pH reductions on tuberization of ‘Dejima’potato in aeroponics. The pH and EC of nutrient solution were adjusted to 6.0∼6.5 and 1.2mS/cm, respectively. On 35th day after planting, plants were subjected to pH 3.0, 4.0, 5.0 and 6.5 for 10hrs. After 5 days mini-tuberization was shown in pH 3.0 treatment and was significantly increased up to 20 days. Temporary low pH treatment resulted in the increase of stolen formation and of tuber dry weight. Number of mini-tubers per plant on 90th-day after planting was 72.1, 69.8, 65.2, and 60.3 in pH 3.0, 4.0, 5.0 and 6.5 respectively.

• Natural Product Sciences
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• v.26 no.3
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• pp.214-220
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• 2020

Brassica oleracea var. gongylodes (red kohlrabi) is a biennial herbaceous vegetable whose edible bulbotuber-like stem and leaves are consumed globally. Sliced red kohlrabi tubers were extracted using methanol and the concentrated extract was partitioned successively with dichloromethane (CH₂Cl₂), ethyl acetate (EtOAc), n-butanol (n-BuOH) and water (H₂O). Repeated column chromatography of EtOAc fraction through silica, sephadex LH-20 and RP-18 gel led to isolation of eleven compounds of which compound 1 was a new glycosylated indole alkaloid derivative, 1-methoxyindole 3-carboxylic acid 6-O-β-D-glucopyranoside. Others were known compounds namely, β-sitosterol glucoside (4), 5-hydroxymethyl-2-furaldehyde (5), methyl-1-thio-β-D-glucopyranosyl disulfide (6), 5-hydroxy-2-pyridinemethanol (7), (3S,4R)-2-deoxyribonolactone (8), n-butyl-β-D-fructopyranoside (9), uridine (10) and three fructose derivatives, D-tagatose (11), β-D-fructofuranose (12) and β-D-fructopyranose (13). Similarly, isolation from CH₂Cl₂ fraction gave two known indole alkaloids, indole 3-acetonitrile (2) and N-methoxyindole 3-acetonitrile (3). The structure elucidation and identification of these compounds were conducted with the help of ¹³C and ¹H NMR, HMBC, HMQC, EIMS, HR-ESIMS and IR spectroscopic data, and TLC plate spots visualization. Compounds 2, 3, 4, 5, 6, 7, 8 and 9 are noted to occur in kohlrabi for the first time. Different bioactivities of these isolated compounds have been reported in literature.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.69-74
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• 2008

This work aimed to evaluate 11 potato families for insect resistance horticultural traits. The families were derived from crosses between introduced insect resistant and adapted genotypes. A randomized complete block design, with three replications was used. The plot consisted of 25 genotypes of a family, summing up to 75 genotypes tested per family. Two susceptible cultivars were included in the experiment as checks. The genotypes were evaluated for insect resistance, tuber yield traits, tuber appearance and tuber skin smoothness. The genetic value for the intensity of insect attack in the leaves and in the tubers was lower(higher resistance) in the 11 families than in the checks. For yield traits, there was no predominant effect among the families regarding the origin of the resistant donor species(Solanum berthaultii and/or S. chacoense). However, there was a large contribution of the C-1485-16-87 recurrent parent in crosses with resistant genotypes for tuber yield and tuber number. In relation to tuber appearance, only the family derived form the C-1485-16-87/ ND140(S. berthaultii) cross did not differ from the checks. had genetic value tuber skin smoothness, it was identified that families derived from S. berthaultii resistant parents showed higher genetic values than the check cultivars. For tuber skin smoothness, the genetic values of the families neither differed significantly from each other nor from the checks.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.637-647
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• 1993

Over 40 per cent Indian population needs to be attended for nutritional improvement. Traditional nutritious food resources though abundantly available but presently less used, if incorporated in the diets, can yield low-cost nutritionally balanced diets. The linear programming (LP)model was used for optimization of food resources to satisfy protein -energy requirements of hard working rural poor. Soybean-a highly nutritious food legume-available at reasonably low price was included along with chick -pea and pigeon -pea for comparison .The three cereals predominantly used in Indian diets -rice, wheat and sorghum -and three typical leafy vegetables namely, spinach , drumstick leaves and rajagira (Amaranths paniculantus) leaves were used for optimization . The contribution of food legume was restricted to supply only 50 per cent of daily protein requirement for maximum protein value. The quantities of other food stuffs namely , milk , sugar , tubers etc. were restricted to nati nal per capita availability. the nutrition satisfaction levels in per cent RDA by the model are 149-250 for protein , 51-106 for fat, 134-362 for iron an d143-1158 for Vitamin-A. Quantities of food legumes, cereals and leafy vegetables ranged from 289-601, 3000-3700 and 360-1200 g/day respectively for a reference family of five hard working rural poor. Daily food resources cost ranged from US$ 0.6 to 1.0 for the family. Amongst food legumes, soybean based diet combinations provide maximum nutritional benefits at minimum cost indicating its suitability for wider adoption by hard working poor.