• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.227-231
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• 1974

During the period from 1971 to 73 physiologic races of potato late blight pathogen, Phytophthora infestans, causing severe losses of seed potato production at Alpine area, Korea, were investigated. In 1971, 68 isolates of the pathogen from various potato varieties were identified by the use of differential host Plants, and found that there were 10 races; 0, 1, 2, 3, 1.3, 1.4, 3.4, 1.3.4, 2.3.4. The most Predominant races for the year were 0 and 3. In 1972, the same procedure was repeated with 62 isolates of the pathogen, and found 5 different races; 0, 1, 4, 1.3 and 1.3.4. The most predominant race for the year was race 0. In 1973, six races; 0, 3, 4, 1.3, 3.4 and 1.3.4 were found from 76 isolates of the year, and the race 0 and 4 apperared as the most Predominant races for the year. Total of 11 races; 0, 1, 3, 4, 1.3, 1.4, 3.4, 1.3.4, 2.3.4 and 1.2.3.4, were found during the period from 1971 to 73 at Alpine area, among which the most predominant races were race 0, 3, and 4. The investigation indicated that the anual incidence of these races largely depended on the climatic conditions of the year.

• Korean Journal Plant Pathology
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• v.11 no.2
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• pp.139-145
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• 1995

경남지방에서 벼도열병균 race의 분포상황을 알기 위하여 1990∼1994년 5개년간 경남지역의 재배품종 잎동열병 병반에서단포자 분리하여 얻은 균주 509 균주를 사용하여 연도별 race 분포상황을 조사한 결과는 다음과 같다. 도내에 분포한 race의 종류는 총 33종류였다. 이 중 KI 100군 race가 16종류로 연차간 분포변동이 심하였고, KI 400군 race가 6종류, KJ 100군 race가 4종류, KI 300군 race가 3종류, KJ 200군 race 2종류, race KJ-301 및 race KJ-401이 각각 1종류씩이었다. KI 및 KJ race의 분포 비율은 각각 11.5∼29.9%와 70.1∼88.5%로 KJ race의 분포밀도가 높았고 분포밀도가 높은 race는 KJ-401 및 KJ-301로 전 race의 26.7∼57.3%를 차지하였다. 지대별 race 구성 특징은 산간 지대에서는 KI race의 분포밀도가 27.3%로 해안지대 6.8%에 비해 훨씬 높았고 KJ 100군 race도 27.7%로 해안지대 11.7%보다 분포비율이 높았다. 반대로 KJ 200군 race는 해안지대가 22.0%로 산간지대 9.7%보다 아주 높았다. 조사기간중 재배된 벼품종과 race의 분포변동을 미루어 보아 race의 분포는 재배된 벼의 도열병균 race에 대한 반응형과 관련이 있을 것으로 사료된다.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.58-65
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• 2016

Powdery mildew is an important disease of the melon (Cucumis melo L.). Seven isolates of powdery mildew fungi were collected from five locations in Korea; Anseong (DH487), Icheon (BN103, BN625, BN968), Yeongam (YA141), Changnyeong (CN582), and Suncheon (SN102). All 7 fungi had a similar trend of conidial chain and conidiophore development as Podosphaera xanthii with fibrosin bodies in mature conidia. Among them, 2 isolates of powdery mildew fungi; CN582 and SN102 showed similar responses to resistance against powdery mildew as the previously reported race 1 and race N2. The isolates YA141 and BN103 showed similar responses as like as race A. However, three isolates of powdery mildew fungi (BN625, BN968, and DH487) showed different responses compared to the previously reported races (1, N1, N2, A, S, and 5). Therefore, these three isolates could be designated as new races in melon. Nine out of 15 commercial melon cultivars in Korea showed resistance to race 1 (CN582). However, the new race BN968 invaded all 15 cultivars. Results of the two molecular markers were consistent in response to disease development by race 1 of Podosphaera xanthii in case of the above mentioned cultivars. This study confirmed the presence of new melon powdery mildew fungi in Korea which are similarly notorious as like as the previously reported race 1. Therefore, breeders can use these two molecular markers for breeding melon in Korea that is resistant to race 1 and as well as to some other races.

• Research in Plant Disease
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• v.26 no.3
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• pp.183-189
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• 2020

Powdery mildew is a common and serious disease of the Cucurbitaceae including cucumber (Cucumis sativus) in most areas of the world. To identify causal agents of the powdery mildew and their physiological race(s), we collected cucumber leaves displaying typical symptoms of powdery mildew from different locations in Korea. Based on morphological and molecular characteristics, all powdery mildew isolates were identified as an obligate biotrophic fungal pathogen, Podosphaera xanthii. After inoculation at melon (Cucumis melo) differentials to identify the fungal race(s), P. xanthii isolate MI180427 and IC190611 were identified as race 1 which has been repeatedly reported as dominant race in Korea. However, another isolate SE180328 produced different disease response in the tested differentials, being identified as race 2 which has not been reported in Korea. To confirm the race of SE180328, we inoculated additional melon differentials and determined the isolate as race 2F that is the prevalent race of powdery mildew in Beijing, China. Report of this new race 2F in Korea will be helpful for future breeding programs to develop resistant varieties to this race.

• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.203-207
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• 1987

Studies were conducted to investigate the race distribution of soybean cyst nematode (Heterodera glycines Ichinohe) in Korea. The results are abstracted as follows. The soybean cyst nematode populations collected from Kangwon Province were identified as races 1 and 3; the nematode populations collected from Kyunggi Province were identified as race 3, 5 and c and those collected from Chungnam Province were identified as races 1 and 5. From the total 21 populations 11 populations or 52.4% of the total were race 1; 6 populations or 28.6% of the total were race 5; 3 populations or 14.3% of the total were race 3 and one population or 4.8% of the total were race c. Soybean cyst nematode populations from the same district, at least from the same 'myeon' district were identified as same race. Of these 4, race 3 has not been recorded in Korea yet.

• Journal of Microbiology and Biotechnology
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• v.29 no.5
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• pp.785-793
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• 2019

Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is the most damaging disease in Brassica crops around the world. In this study, we developed a molecular marker specific to Xcc race 5. To do this, the available whole genome sequences of Xcc races/strains and Xc subspecies were aligned and identified a highly variable genomic region (XccR5-89.2). Subsequently, a primer set covering the 'XccR5-89.2' region was designed and tested against the genomic DNA of Xcc races/strains, Xc subspecies and other plant-infecting bacterial strains (Pseudomonas syringae pv. maculicola and Erwinia carotovora subsp. carotovora). The results showed that the 'XccR5-89.2' primer pair amplified a 2,172-bp fragment specific to Xcc race 5. Moreover, they also amplified a 1,515-bp fragment for Xcc race 1 and an over 3,000-bp fragment for Xcc race 3. However, they did not amplify any fragments from the remaining Xcc races/strains, subspecies or other bacterial strains. The 'XccR5-89.2' primer pair was further PCR amplified from race-unknown Xcc strains and ICMP8 was identified as race 5 among nine race-unknown Xcc strains. Further cloning and sequencing of the bands amplified from race 5 and ICMP8 with 'XccR5-89.2' primers revealed both carrying identical sequences. The results showed that the 'XccR5-89.2' marker can effectively and proficiently detect, and identify Xcc race 5 from Xcc races/strains, subspecies and other plant-infecting bacteria. To our knowledge, this is the first report for an Xcc race 5-specific molecular marker.

• Korean Journal Plant Pathology
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• v.3 no.3
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• pp.159-163
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• 1987

In order to investigate the distribution and density of root-knot nematodes in economic crops, samples were collected from 3,226 fields of 18 economic crops. Nematodes were extracted using a modified Baermann's funnel technique. Identification of races was based on the differential host-test for Meloidogyne spp. by Tayler and Sasser. M. hapla was dominant in fields in the middle parts of Korean peninsula; M. incognita, in the southern parts, and distribution of M. javanica was limited to Jeju island and southern seaside areas. Two races of M. arenaria identified in this study were races 1 and 2. The three races identified in M. incognita were races, 1, 2 and 3. Of these races, race 1 of M. arenaria and race 3 of M. icognita were identified for the first time in Korea.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.427-431
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• 1998

This study was undertaken to investigate the effect of exercise induced pulmonary hemorrhage(EIPH) on the finishing position of racehorses, 400 bleeders(305: 1 time, 76: 2 times, 19: 3 times, total: 514 cases) which had bled(EIPH) from their nostrils after their races at the Seoul racecourse during the 5 years period('93-'97) were analyzed for this study. The ratio of bleeders to total racehorses in finishing position 1-3,4-6, 7-9 or above 10 was 0.55, 0.84, 0.90 or 1.13%, respectively. There is tendency to higher incidence of bleeding in the later positioned racehorses group. To analyze the correlation between EIPH and finishing position, finishing potion of each EIPHed horses' was checked at 7 successive races(3 races each before/after EIPH. The average final position at the -3rd race, -2nd racer -lst racer EIPHed race, 1st race,2nd race and 3rd race of each bleeder was 5.85. 5.94, 6.21, 7.32, 7.20, 6.51 and 6.53, respectively. Raring times were adjusted to 1,000 m equivalent. Average racing times of the -3rd race,-2nd racer -lst raced EIPHed race, 1st race, 2nd race and 3rd race of each bleeder was 67.1, 67.1, 67.2, 67.6, 67.5, 67.4 and 67.3 second, respectively. Bleeders which finished the race within 1 second following the winners were 25. 3% of total bleeders. The rest 74.7% reached at the finish line 1 second later than the winners. Particularly 46.3% of bleeders were above 2 second later. Therefore this study suggested that bleeding has effect on performance of the racehorse, consequently it make bleeders be placed later positions.

• Korean Journal of Childcare and Education
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• v.18 no.2
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• pp.85-103
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• 2022

Objective: This study examined five- to six-year-old children's categorization of mixed-race faces and how it was affected by perceptual individuation training (PIT) for other-races. Methods: Sixty-five children attending classes for 5-year-olds in childcare centers were shown happy and angry faces of Korean and African American mixed-race people, along with neutral faces of Korean and African American monoracial people. They were asked to categorize the faces into same-race or other-race. After the pretest, participants received a PIT for either African American (other-race) or monkeys. Then the racial categorization task was administered again as a posttest. Results: Children showed no general tendency to categorize mixed-race faces as out-group in the pretest. Yet, the PITs further reduced children's categorization of mixed-race faces as out-group. In particular, the effect was clearly evident in children who received the PIT for other-race. Conclusion/Implications: The results suggest that the tendency to categorize mixed-race faces as an out-group may not be evident in early childhood and that experiences of perceptually identifying other-race individuals may help children view mixed-race individuals as being in the ingroup, at least perceptually.

• International Journal of Advanced Culture Technology
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• v.7 no.1
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• pp.225-230
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• 2019

In order to improve performance for the size of the rat-race ring coupler, the CCL is used for the realization as the delay line. As realizing lower coupling coefficient, the ratio of the size-reduction for the CCL is enhanced. The CCL is alternated with ${\lambda}_g/4$ of the rat-race ring, and optimized two CCLs are inserted for the size-reduction. the coupling coefficient is 0.2, and electrical lengths of each CCL are $28.2^{\circ}$ and $21.7^{\circ}$. Designed rat-race ring using the CCL has the size of $18.76{\times}20.45mm^2$ and the size-reduction ratio of fabricated rat-race ring using the CCL has 76.8%. Also, fabricated rat-race ring is measured the insertion loss of 3.20dB at the center frequency of 2.45GHz and the 20dB bandwidth is 24.04%. Differenced magnitude and phase between threw port and coupled port are measured 0.1dB and $177.4^{\circ}$, respectively. These performances are almost same compared with the conventional rat-race ring. Suggested application of the CCL can be used various devices and circuits for the size-reduction.