• Research in Plant Disease
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• v.29 no.3
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• pp.258-267
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• 2023

Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum (Fon) is a serious disease in watermelon cultivation. Most of commercialized watermelon cultivars to Fusarium wilt are susceptible in Korea. Fon isolates were divided into four races (races 0, 1, 2, and 3), based on pathogenicity in four watermelon differentials including 'Sugar baby', 'Charleston gray', 'Calhoun gray' and 'PI-296341-FR'. We obtained 7 isolates of Fon and tested to determine race of the fungal strains. Fon KACC 40902 and Fon HA were race 0 and Fon NW1, Fon NW2, Fon CW and Fon KACC 40901 were race 1. And Fon KACC 40905 was race 2, but race 3 isolate of Fon was not founded. We also tested virulence of seven Fon isolates on three-susceptible cultivars of watermelon. The isolates showed different virulence on the cultivars. In addition, to study the resistance characteristics of watermelon to Fon, we selected three moderately or highly resistant cultivars of watermelon and occurrence of Fusarium wilt in seedlings of the cultivars by seven Fon isolates was investigated. Among them, 'Calhoun gray' is highly resistant to six Fon isolates except Fon KACC 40905. On the other two cultivars, disease severity of Fusarium wilt caused by each isolate was positively correlated with the virulence of the Fon isolates. The results suggest that resistance of the watermelon cultivars to Fon isolates is likely affected by the virulence of the pathogen.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.95-113
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• 1988

In order to find out changes of chemical components related to browning of dried jujube, four varieties were subjected to the proximate analysis. Boeun, one of the major varieties in Korea, was sun-dried and stored for 12 months and analyzed periodically for one year. Browning, titrable acidity, pH, contents of ascorbic acid, organic acid, total amino acid, free amino acid, free sugar, hydroxymethylfurfural (HMF) and phenolic compounds were determined and compared with those of fresh jujube. The results obtained are summarized as follows; 1. In comparison with other similar fruits, jujube was high contents of ascorbic acid (62-79mg%) and carbohydrate (22-28%) excluding fiber. 2. Browning was increased in both steam-treated and nontreated plot together as storage period was prolonged. 3. Ascorbic acid content of fresh jujube was as high as 297.4mg% DB, but it was decreased to 20.2mg% DB, after 12 months storage. Therefore, loss of ascorbic acid was very great up to 93% of its original content. 4. Five kinds of organic acid, oxalic, succinic, fumaric, malic and citric acid were identified as major organic acids. It was interesting that only fumaric acid content was increased while others decreased during storage. 5. Seventeen kinds of amino acid were identified in the analysis of total amino acid content. Major amino acids were found to be proline, threonine, glutamic acid and lysine. During 12 months storage, 30% of original total amino acid was decreased and this was mostly accounted for free amino acids. 6. Threonine, proline, alanine and valine were identified as free amino acids which showed 85% decrease after 12 months storage. 7. Free sugars of jujube were composed of fructose, glucose and sucrose. They showed 24% decrease after 12 months storage, Especially sucrose was not detected after 4 months storage. 8. HMF of dried jujube was isolated and identified. Its content was increased up to great extent as storage period prolonged. 9. Caffeic, ferulic and P-coumaric acid were identified as jujube phenolic compounds which were significantly decreased during storage. In conclusion, non-enzymatic browning was thought to be more important than enzymatic reaction in the dried jujube. Amino-carbonyl reaction, ascorbic acid oxidation and reaction between phenolic compounds and sugar or nitrogen compounds were observed to be related to this browning.

• Korean Journal of Food Science and Technology
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• v.2 no.1
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• pp.72-80
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• 1970

The chemical composition of the of grape juices produced in Korea in 1969 were analyzed and the amino acids and sugars in these juices were detected by means of paper partition chromatography. The results are summarized as follows: 1. Less sugar and amino-N and more acid were contained in Korean grape juices than those of foreign's, and tannin content was not so different as foreign's. 2. More sugar, amino-N and tannin and less acid were contained in the juices of Campbell Early obtained in Anyang district than in Taejon and Pohang districts. 3. Twenty-one amino acids detected in grape juices were distributed as following frequency. Aspartic acid, serine, glycine, asparagine, lysine, arginine, threonine, alanine ${\gamma}-amino$ butyric acid, valine, leucine, proline (in 11 varieties), glutamine, tyrosine(10), cystine(9), glutamic acid, Hydroxyproline(8), isoleucine(4), phenylalanine, unknown(3). 4. Alanine was mostly abundant in all varieties and ${\gamma}-amino$ butyric acid was next and the decreasing order were arginine, valine, leucine, proline, glutamine, threonine, etc. in the amount. 5. Number of amino acid detected in grape juices of each varieties were 20 sorts in Delaware(Anyang), 19 in Black Hamburg, and Schuyler, 18 in Campbell Early(three districts), Delaware(seedless, Taejon) and Alden, 17 in Niagara, 16 in Muscat Hamburg, and 15 in Golden Muscat. 6. Number of essential amino acids contained in Delaware(Anyang) and Black Hamburg were 6 sorts and in Campbell Early (Anyang), Niagara and Muscat Hamburg were 5 and in others 4. 7. The same number of amino acid were detected in the juices of Campbell Early obtained from three districts, but hydroxyproline was detected in that of Anyang only, while isoleucine was appeared in those of Taejon and Pohang. 8. Glucose, fructose were detected in all grape juices.

• Food Science and Preservation
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• v.13 no.1
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• pp.43-49
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• 2006

The chemical components of Korean paprika according to cultivars were investigated and analyzed to provide basic data for food materialization and processing. Nitrogen free extract contents of President, Special and Fiesta were 6.64, 6.22 and $6.01\%$ respectively. The contents of crude lipid and crude fiber in the Special, President and Fiesta were similar. Mineral components of paprika were rich in $K(83.41\-152.98\;mg\%),\;Mg(28.66\~39.46\;mg\%)\;and\;Mn(10.34\~18.96mg\%)$. Among the cultivars of paprika, K content had a slightly higher level in the President than those of Special and Fiesta. The major free Sugars of paprika were glucose $(1.36\~1.45\%)$ and fructose$(0.06\~1.53\%)$, respectively. The contents of total amino acids in paprika were $1,168.08\;mg\%$ in the Special, $1,112.97\;mg\%$ in the President and $874.79\;mg\%$ in the Fiesta. The major amino acids in the paprika were lysine, aspartic acid and glutamic acid Abundant organic acids of paprika were tartaric $(2.34\~4.32\;mg\%)$, succinic $(2.01\~2.42\;mg\%)$ and malic acids $(0.67\~1.72\;mg\%)$. Eight fatty acids in paprika were identified and the major fatty acids were stearic $(15.11\~34.68\%)$ and linoleic acids $(32.12\~60.36\%)$. The contents of ascorbic acid in paprika were $263.45\;mg\%$ in the Special, $284.24\;mg\%$ in the President and $206.34\;mg\%$ in the Fiesta. Total phenolics and carotenoid contents were higher in President cultivar than any other cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.185-197
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• 1992

Differences in the amount and chemical characteristics of the epicuticular waxes on rice leaves were studied for the active tillering and heading stages of rice varieties differing widely in gross leaf-surface property and genetics. The amount of waxes on surfaces of rice leaf-blades was determined by extraction with chloroform and chemical composition of the waxes was characterized by thin layer chromatography, gas liquid chromatography and infrared spectrophotometry. The amount of waxes varied by variety and significantly with growth stage. The amount at the heading stage was 1.7 to 3.6 mg/g fresh weight of leaves, which was two to three times as much as that at the tillering stage of 0.8 to 1.8 mg/g fresh weight. The waxes consisted of seven chemical classes, namely diols, fatty acids, fatty alcohols, fatty aldehydes, fatty esters, saturated and unsaturated hydrocarbons. Diols and unsaturated hydrocarbons were identified as new chemical classes of the rice epicuticular waxes. The polar constituents such as dials, fatty acids and fatty alcohols and the non-polars such as fatty aldehydes, fatty esters, and saturated and unsaturated hydrocarbons were identified at the heading stage, but at the tillering stage only the non-polar compounds were identified. In the carbon numbers (C) of the chemical classes, diols were composed entirely of C30 and acids were mainly of C30 and C31. In alcohols, primary alcohols were composed of C13 and C32, and the secondary alcohols were of C14, C16 and / or C30 regardless of the rice varieties. The acid portion of fatty esters, mainly composed of C22 and C23, showed low cabon numbers compared with the aldehydes. The alcohol portion of them showed a wide distribution in carbon numbers from C13 to C26 depending on the rice varieties. Hydrocarbons had odd carbon numbers, consisting mainly of C29 and C31.

• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.241-245
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• 1983

PraziquantEI ($Distocide^{\circledR}$), the KcrEan product, was tEstEd for its safety and Efficacy in treatmEnt of Clonorchis sinensiJ infccticn during the period from April to SeptembEr, 1983 in Korea. A total of 55 egg positive cases were selected and treated with the regimen of 25 mg/kg t.i.d. for 1 day (total 75 mg/kg). The follow-up stool examination was done in 47 cases by cellophane thir;k smear and Stoll's egg counting techniques. The 8 uncured cases were treated again with the same regimen. The laboratory tests for blood picture and liver function were done in 27 cases and compared before and after the treatment. The results obtainEd are as follows: 1. After single course treatment, the cure and egg reduction rates were 83.0 and 99.1% respectively. With the second treatment, excellent results of 100% in both rates were obtained. 2. Several kinds of side effects such as dizziness, headache, etc. were complained by 29 cases (61.7 %), however, those were so mild and transient that no special treatment was necessary. 3. No significant change in laboratory findings was recognizable before and after the treatment. From the above results, it is concluded that $Distocide^{\circledR}$ is as effective and safe as $Biltricide^{\circledR}$ and highly recommendable in treatment of C. sinensis infection.

• Korean journal of applied entomology
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• v.18 no.4 s.41
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• pp.183-188
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• 1979

The study has been carried to describe a new disease of strawberry in Korea, which was found in 1977 at Kimhae. Symptom of the disease occurred mainly on leaves as showing large annular brown spots or 'V' shaped brown lesions. Many of dark pycnidia were observed from the both side of old lesions. The pathogen was identified as Dendrophoma obscurans (Ell. & Ev) Anderson which has not been described in Korea as a pathogen of strawberry disease. The common name of the disease was given, temporaly, as Annular leaf blight of strawberry. In the laboratory study, light was necessary for the production of pycnidia and potato dextrose agar was the best media for tile pycnidia formation. There were some difference on resistance to the disease among 48 tested strawberry varieties though none of them shelved highly resistant reaction, and the older leaves showed more susceptible reaction than younger ones.

• Journal of Dairy Science and Biotechnology
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• v.33 no.4
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• pp.253-262
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• 2015

The authentication and implications of misleading labeling in milk and dairy products is important to protect against cheating consumers from adulteration and to alert sensitive consumers to any undeclared potential allergens. This need to support milk and dairy products labeling has led to the development of specific analytical techniques for the analysis of milk and dairy products ingredients. Recently, several methods based on polymerase chain reaction (PCR), including restriction fragment length polymorphism (PCR-RFLP), multiplex PCR, species-specific PCR, and real-time PCR, have been proposed as useful means for identifying species of origin in milk and dairy products, as well as quantifying and detecting any adulteration. These methods have particular advantages owing to their high specificity and sensitivity, as well as rapid processing time. In this review, we provide an updated and extensive overview of the PCR-based methods used for milk and dairy products authentication with a particular focus on the application of PCR methods to detect adulteration.

• Korean journal of applied entomology
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• v.12 no.3
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• pp.121-124
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• 1973

From the new rice variety Tong-il, disease symptoms similar to Fusarium leaf spot reported in Japan was observed in Korea. Causal organism was isolated and identified as Fusarium nivale causing Fusarium leaf spot through the study of conidia shape, ascus formation on diseased spot, and ascospore. These results also showed good agreement with that of other investigators. Under the field condition, marked occurrence of this disease has observed by heavy nitrogen application. The optimum temperature for the growth of this fungus was $24^{\circ}C$.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.377-379
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• 1996

1990이래 단감재배 면적이 확대되고 있는 경주 및 그 인근의 포장으로부터 이미 알려진 병징과는 전혀 다른 병징을 나타내는 병을 단감의 주요 품종인 부유의 이병 잎과 신초로부터 병원균을 분리하고 그 병원 곰팡이의 병원학적 특징을 조사하였다. 이 병은 신초선단부 잎에서 발생하여 아래잎으로 진전되며, 잎에는 잎가장자리나, 중앙부 등 일정한 부위가 없이 발병하여 회갈색의 둥근 무늬가 확대되기도 하고, 심하면 잎이 고사탈락하기도 한다. 심한 경우 병반의 크기가 전체 잎의 1/3이상을 차지할 정도로 크게 확대되었다. 신초는 병의 진전이 심해지면 고사함으로서 나무 생육이 급격히 중지되거나, 나무 수세가 떨어져 수확에도 지장을 주고 있다. 발생시기는 6월 중.하순~7월, 9~10월 초순까지 발병하며, 병든 잎과 가지를 채집하여 병원균을 순수 분리하여 Guba(1949년), Sutton(1969)와 Steyaert(1971)의 분류기준에 따라 동정한 결과는 다음과 같았다. 병원균의 분생포자의 크기는 23.1$\times$7.1 $\mu\textrm{m}$, color cell의 크기와 수는 15.65 $\mu\textrm{m}$, 3개이었고, 포자의 윗부분은 다갈색이었으며 아래부분은 올리브색이었다. Setrlae의 크기와 개수는 23.6 $\mu\textrm{m}$, 2~4(3)개이고, pedicle의 길이는 5.17 $\mu\textrm{m}$였다. 이상의 결과에 근거하여 이 병원균을 Pestalotiopsis theae로 동정하고 국내미기록병으로 보고한다.