• Asian Journal of Turfgrass Science
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• v.12 no.3
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• pp.215-224
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• 1998

These experiments were conducted to compare the growth characteristics, cold and drought tolerances, disease tolerance and color of the 23 varieties of four different species of cool-season turfgrass introduced from the United States of America and Europe at Yonam College in 1995. Newport and Glade of 8 Kentucky bluegrass varieties were recorded better marks than others. Newport variety was recorded the good marks in the disease tolerance of summer seasons, uniformity, coverage and texture, but the bad marks in color, drought tolerance and rust tolerance and stay green of automn seasons. Glade variety was recorded the good marks in the disease tolerance of summer seasons, uniformity and coverage, but the bad marks in drought tolerance, texture and Pythium blight tolerance. Revel and Revel Jr of 5 tall fescue varieties were recorded better marks than others in color, shoot density, uniformity, coverage, and tolerance of Pythium and Fusarium blight disease. All of red fescue varieties died of disease for rainy season however texture was the finest of all the species in spring season. Dandy of 4 ryegrass varieties was recorded better marks than others in color, shoot density, coverage, drought tolerance and tolerance of Pythium and Fusarium blight disease but texture.

• Research in Plant Disease
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• v.22 no.3
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• pp.184-189
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• 2016

To select resistant oil seed crops against two species of root-knot nematodes, Meloidogyne incognita and M. arenaria, 10 cultivars of sesame (Sesamum indicum L.) and 10 cultivars of perilla (Perilla frutescens var. japonica) were screened in greenhouse pot test. All sesame cultivars tested were resistant to M. incognita but susceptible to M. arenaria. While, perilla was resistant to both Meloidogyne species. Therefore, perilla cultivars could be used as rotation crop in greenhouse infested with both M. incognita and M. arenaria. But, sesame cultivars only can be used as a rotation crop in greenhouse infested with M. incognita but not for M. arenaria.

• 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 applied entomology
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• v.11 no.2
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• pp.61-68
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• 1972

This study has been carried out to investigate the varietal resistance of Tong-il rice variety (IR-667) at the seedling stage to the brown planthopper. Nilaparvata lugens STAL, and further to know the biological effects of the varieties to the insects. The results obtained were as followings; 1. Tong-il variety tested in this experiment was susceptible to the brown planthopper but it seemed to be a little more tolerable than the Japonica varieties which had been recommended in Korea. 2. Tong-il variety (Suwon 213, Suwon 213-1, Suwon 214, and Suwon 215) was highly prefered by brown planthopper for feeding to the Korean recommended varieties Paltal, Jinheung, Akibare, and Shin #2. 3, The resistant varieties Mudgo, Kayama MGL-2, and Karsamba ASD-7 which showed low feeding preference exhibited higher ovipositional preference than the susceptible varieties. Relatively greater number of eggs was recorded on the Tong-il variety (Suwon 213, Suwon 213-1, and Suwon 215) in comparison with the Korean recommended varieties, 4, When the female brown planthopper adults were caged on Tong-il variety (Suwon 214) and the resistant variety Karsamba ASD-7 separately, greater number of eggs were observed on Suwon 214 and less on Karsamba ASD-7, while when two varieties Suwon 214 and Karsamba ASD-7 were given together in the same cage, Karsamba ASD-7 was much more prefered for oviposition to Suwon 214. 5. There was no difference in e99 Periods and their hatchal\bility between the resistant and susceptible varieties, but nymphal periods, rate of adult emergence, longevity of the adult, and its fecundity were significantly different according to the varieties.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.818-829
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• 2016

This study evaluated the responses of 18 potato cultivars to three levels of salinity stress (electrical conductivity, EC: 1.0, 4.0, and $8.0dS{\cdot}m^{-1}$). Stem, leaf, root, chlorophyll, tuber yield, and proline content were investigated and statistically analyzed using analysis of variance (ANOVA) and correlations. Stem number and stem diameter were not affected by salinity, but stem length and aerial weight showed highly significant responses to salinity. Aerial weight decreased with increasing salinity levels in most cultivars, while it increased in some the cultivars 'Daejima', 'Goun', 'Haryeong', and 'LT-8'. Leaf number, leaf area index, and leaf weight were most significantly affected by salinity and the cultivar ${\times}$ salinity interaction. Root length, root weight, total chlorophyll and chlorophyll a were affected by salinity, but not by the cultivar ${\times}$ salinity interaction. The opposite trend was shown in chlorophyll b. Although there was great variability among cultivars, tuber yield decreased in all cultivars, and was most significantly influenced by salinity and the cultivar ${\times}$ salinity interaction. 'Superior', 'Kroda', 'Romana', and 'Duback' gave better tuber yields under salinity at EC 4.0 and $8.0dS{\cdot}m^{-1}$ than the cultivars with better aerial weights. Proline content was increased by salinity in all cultivars, and was more remarkable in the cultivars with better aerial weights than in cultivars such as 'Superior' and 'Kroda' with better tuber yields. Leaf number, leaf area index, leaf weight, and root length parameters were considered to be useful criteria in the evaluation of salt tolerance because of their high positive correlation with tuber yield; however, given its negative correlation with tuber yield under high salinity, proline content was not. Salinity tolerances varied greatly among potato cultivars. The low correlation between growth and yields of aerial parts under high salinity suggests that, in commercial agriculture, it might be more practical to compare relative yields to controls. Additionally, 'Superior', 'Kroda', 'Romana', and 'Duback' might be very useful cultivars to use in breeding programs to develop salinity-tolerant potatoes, as well as for sustainable potato production in saline areas.

• Research in Plant Disease
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• v.23 no.3
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• pp.249-255
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• 2017

The rice blast fungus is a representative model phytopathogenic fungus in which Gene-for-Gene interaction with host rice is applicable. After 1980, eight differential varieties have been constructed and classified to analyze the race of rice blast isolates in Korea. However, since there is limited information about the genetic background of rice blast resistance genes within the Korean differentials, scientific analysis on the emergence of new race or resistance break down was difficult. Recently, a differential system has been developed using monogenic resistance lines to understand the interactions of pathogen race and rice resistance genes. In this study, a total of 50 isolates were selected from four different races isolated in Korea, and they were inoculated into monogenic lines. As a result, the isolates in the same race classified by the Korean differential system reacted differently in single monogenic lines. This suggests that the isolates categorized as the same race group contains different avirulence genes and furthermore, it is presumed that the Korean differential system is difficult to provide useful information for breeding program. For this reason, introduction of differential system using monogenic resistance lines is required in addition to the current system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.501-505
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• 2003

The growth characteristics and damage of naked barley infected with barley yellow mosaic virus (BaYMV) were investigated between resistant and susceptible varieties in habitual field plot of BaYMV BaYMV of the barley plants with typical disease symptom were identified by enzyme linked immunosorbent assay (ELISA) test. The visual degree (0-9) based on disease symptoms of BaYMV was different as 9 and 1 between susceptible variety Baegdong and resistant variety Naehanssalbori, respectively. Susceptible variety, Baegdong showed significant damage in culm length, number of kernel per spike and tiller per square meter but not in 1,000 kernel weight, so these results caused yield reduction to only 80% comparing to the control. Seed germination did not affected by BaYMV infection both in susceptible and resistant variety. In grain quality test, abortive grain yale and crude protein content were significantly increased compared to the control. The relationships between BaYMV infection and growth characteristics showed the negative correlations in culm length, number of tiller, 1000 kernel weight and yield, but it showed the positive correlation in crude protein contents. These results implied that BaYMV can affect not only barley growth and yield but grain quality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.111-116
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• 2013

This experiment was carried out to select a resistant corn variety for rice black-streaked dwarf virus (RBSDV) disease in a RBSDV prevalent area (Gochang of Jeollabukdo) from 2006 to 2008. Ten corn varieties for silage preparation were cultivated with first cropping and second cropping system in an RBSDV field, and were tested outbreak rates of RBSDV and dry matter (DM) yield of forage. The outbreak rates of RBSDV were significantly different between corn varieties. Therefore, the resistance degree of corn varieties for RBSDV were divided into 4 groups; very resistant ('Kwangpeyongok' and 'Kwanganok'), resistant ('P3156' and 'P3394'), mildly resistant ('Cheonganok' and 'P32P75') and susceptible ('Suwon19', 'DK697' and 'GW6959') groups respectively. DM yield of forage in RBSDV fields exhibited comparatively significant differences between varieties (p<0.05). DM yield of resistant varieties ('Kwangpeyongok', 'Kwanganok', 'P3156' and 'P3394'), were higher (14~26%) than those of susceptible varieties ('Suwon 19', 'DK697' and 'GW6959'). Therefore, resistant varieties were recommended for increasing forage productivity in field of RBSDV prevalent areas.

• KOREAN POULTRY JOURNAL
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• v.4 no.9 s.35
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• pp.33-36
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• 1972

1. 마렉 감염계는 환경을 오염한다. 3. 감염원인 병독은 오랫동안 생존한다. 3. 따라서 감염성계는 오염환경에서 직접, 간접 간염한다. 이 병의 감염경로는 아직 확정되어 있지 않으나 주로 기도감염일 것으로 인정되고 있다. 4. 본 병의 감염은 병독 보유계의 우모근이 각화하여 탈각하는 상피세포중에 함유되는 병원성 병독이 야기 한다는 것은 확정적이다. 또 이 방법이 마렉병 감염을 반복하는 유일의 원인으로 생각하고 있다. 5. 본 병의 개란전파에 대해서는 거의 없는 것으로 알고 있으나 Sevoian은 전달의 가능성이 있다고 한다. 6. 임파종증일때와 마찬가지로 저항성품종과 감염성품종을 선택 도태를 함으로써 만들어져 있다. 이들은 마렉병에 대하여 저항성품종은 5$\%$의 발병성을 나타내고 감염성 품종은 90$\%$의 발병성을 나타내고 있다.

• Korean journal of applied entomology
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• v.4
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• pp.51-54
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• 1965

The study was initiated to investigate the nature of varietal resistance to the rice stem borer (Chilo suppressalis WALKER), specially the rotation of the resistance to the silica and nitrogen content of the host Plants. 1. The body freight of the larvae, reared on the stem of the various varieties of rice plants, when weighed at the age of 25 days old, showed great variation, and ranged from 21.24 mgrs. to 45.77 mgrs. depending on the used varieties of tile rice plants. And generally the varieties of Indica types were showed greater body weight than that of Japonica types in this experiments. 2. The positive correlation coefficients of percent survivals to body weight, developement, oviposition preference and rate of damage to host plants were significant, and consequently the percent survival could be used as a criteria of resistance. 3. The content of silica in the host plants was significantly correlated with both the degree of boring on the leaf and attractovemess of larvae, and the total nitrogen content of plants showed significant positive correlation coefficient with larval attractivenes, but not significant with the degree of boring on the leaf. 4. Since the attractiveness and boring manner were significantyly correlated to resistance criteria of rice plant to the pest, it could be considered that the resistance is the results of chain reaction of the factors mentioned above.