• International Journal of Industrial Entomology and Biomaterials
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• v.12 no.1
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• pp.35-39
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• 2006

Fifty-six indigenous and twenty nine exotic mulberry varieties were screened against powdery mildew, Myrothecium leaf spot, Pseudocercospora leaf spot, sooty mold and bacterial leaf spot for a period of three years under field condition. The percent disease index (PDI) was recorded during peak season of the foliar diseases. Out of eighty-five varieties studied, ten varieties were highly resistant and eight were resistant to powdery mildew; six varieties were immune and seventy-eight varieties were highly resistant to Myrothecium leaf spot; sixty varieties were highly resistant and 21 were resistant to Pseudocercospora leaf spot; forty four varieties were highly resistant to sooty mold and two varieties were immune and fifty-eight were highly resistant to bacterial leaf spot. Lowest cumulatative disease index was observed in M. multicaulis (7.28) followed by Thailand lobed (7.85) and Italian mulberry (8.06).

• Korean journal of applied entomology
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• v.36 no.2
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• pp.185-191
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• 1997

One hundred seventy five red pepper varieties were bioassayed for selecting resistant varieties to northern rootknot nematode, Meloidogyne hapla. Fifteen native varieties (IT 102794, 104806, 105516, etc) and two imported varieties were proved to be resistant while the currently cultivated varieties such as Hongtap, Kangsan, Hongsil, and Bookang were moderately resistant to the nematodes. Resistant varieties resulted in less nematode infection and development than did the susceptibles. Roots of the resistant strains had significantly higher esterase and peroxidase activities than did those of the susceptibles.

• Korean journal of applied entomology
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• v.5_6
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• pp.47-54
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• 1968

In order to develop an effective control measure for the rice stripe disease, methods of testing for resistance and selection of resistant varieties among the leading varieties were investigated. For use as a parent in breeding for resistant variety to the disease, total of 410 rice varieties were tested. 1. Disease occurrence was higher at group inoculation than that of individual inoculation in comparing the inoculation methods. 2. In both methods, Lacrose responded susceptible; Zenith and St. No. 1 resistant, and the rest moderate. 3. Suseptible symptom type A was prevalant among the susceptible varieties, while resistant symptom type C was abundant among the resistant varieties, There was no difference between the inoculation methods. 4. 410 rice varieties tested could he divided into 3 groups as susceptible (21 varieties), moderate (377 varieties) and resistant (12 varieties). Resistant varieties wers St. No. 1 and 2, Shin-2, Gulfrose Bonnet, Arkrose, Sun Bonnet, Zenith, Yeechunchilichal, Norm-24, Opaikjoke, Yangchubatchal and Nonglimana-1, Nams-97,-149, -159, -216. -265, Iri-243, -265, Kanchuk -5, -7, -8, -10, -41, -43, -47, -50, Suwon-56, -77, Norin-22, Cod-4. Lacrose and Chukna were susceptible. 5. There was slight differance in the disease occurrence in regard to maturing period. However late varieties seem to be more resistant than early or medium varieties. The medium varieties seem to be susceptible. Most of the introduced varieties from foreign countries and the upland cultivated varieties were resistant. 6 Among the leading varieties, Shin-2 in Kangwon-Do was resistant, Kosi in Choongchung-Do, was susceptible, aad the others were moderate.

• Korean journal of applied entomology
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• v.11 no.2
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• pp.55-60
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• 1972

The study has been carried to investigate the nature of resistance in rice varieties against bacterial leaf blight caused by Xanthomonas oryzae (Uyeda et. Ishiyama) Dowson. In this study, differences on several morphological histological and bacterial growth in rice leaf extract from different varieties were examined. Shirogane and Norm 6 as resistant varieties, Paldal as moderately resistant, and Jinheung, Kimmaze and Suwon 213 as susceptible varieties were used throughout the experiment. 1. Susceptible varieties Jinheung, Kimmaze have more hydathods in flag leaf than resistant varieties but there were no difference between resistant varieties and moderatly resistant varieties. 2. Average length of xylem vessel elements were 50r longer in leaf veins of susceptible varieties Jinheung, Kimnaze and Suwon 213 than those of resistant varieties, but there were no difference among Paldal, Norm 6 and Shirogane. 3. Kimmaze and Suwon 213 have larger diameter of xylem vessel elements than those of other varieties examined. However, it did not differ significantly between resistant varieries and susceptible varieties statistically. 4. Jinheung and Kimmaze have more secondary xylem vessels in root of 6-7th leaf stage than those of Shirogane and Norm 6. Suwon 213, however, showed least number of secondary xylem vessels exceptionally. 5. Leaf extract from resistnat variety Shirogane, suppressed bacterial growth significantly when compared with those from other varieties. 6. Bacterial growth in autoclaved leaf extract from resistant varieties and susceptible varieties did not show any noticeable difference. In general, fresh extract maintained more bacteria than in autoclaved extract after 48 hours of incubation period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.4 no.1
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• pp.103-108
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• 1968

Resistance to various diseases of Korean native varieties were investigated in field. The results obtained are summarized as follows: 1) The varieties Ubangtchio and Osib-eubthio were moderately resistant to black shank, but Suantchio, Usultchio and Gwangtchio were slightly resistant. Dixie Bright 101, $H_2$ and Bright Yellow 4 were more resistant to black shank than any of the Korean native varieties. 2) Mokgitchio, Ubangtchio and Osib-eubtchio were moderately resistant to black root rot, but Useultchio Suantchio and Hoetchio were susceptible than Others. 3) Muktchio, Hoetchio and Ubangtchio were slightly resistant to wild fire. 4) Osib-ebthio was highly resistant to brown spot, but Ubangtchio, Hyangtchio and Mokgitchio were moderately resistant and Useultchio was susceptible to brown spot, but it was resistant than Bright ellow 4 or Bernhart 1000-1. 5) Hyangtchio was slightly resistant to CMV-Y. According to these results, except Virus disease, Ubangtchio was resistant to all of the above mentioned diseases. Osib-eubtchio, Hoetchio, Hyangtchio and Suantchio showed proferable disease resistant and these might be well utilized as breeding materials.

• Korean journal of applied entomology
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• v.14 no.3 s.24
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• pp.133-136
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• 1975

Influence of susceptible and resistant soybean varieties to the development of the soybean cyst nematode(Heterodera glycines) was examined. It does not seem likly that there are any differences between varieties in attracting the Second Stage larvae of the nematode. In susceptible varieties, there were large populations and three generations during a ten·week examination period, while the resistant varieties maintained very low populations and had only two generations.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.293-297
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• 2019

Leaf rust is the most widespread and destructive fungal disease, and outbreaks have always caused considerable losses in wheat yields. Thus, worldwide increases in wheat production depend on the development of leaf rust-resistant wheat varieties. In this study, we evaluated the resistance of forty Korean wheat cultivars to leaf rust at the seedling stage. Only two Korean wheats, Ol and Jonong, were resistant to leaf rust, whereas the remaining thirty-eight Korean wheats were susceptible to leaf rust. The Ol and Jonong varieties presented larger dry seed weights and higher antioxidant activity in response to leaf rust than the susceptible wheat varieties. No differences in ${\beta}$-1,3-glucanase activity or chlorophyll content between resistant and susceptible wheat varieties were observed. Overall, these results are important for the development of wheat varieties that are highly resistant to leaf rust and to understand the underlying mechanisms that confer leaf rust resistance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.151-155
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• 2005

This study was carried out to get information for diversifying of resistant genes to bacterial blight (BB) in Japonica cultivar breeding programs. TWo hundred nine rice varieties were tested for qualitive resistance to four races of BB; HB9101 isolate for race K1, HB9102 isolate for race K2, HB9103 isolate for race K3, and HB01001 isolate for race K3a. Two hundred nine rice varieties were divided into five groups according to their race reaction. Fourteen Tongil-type varieties and ninetyseven Japonica varieties showed susceptible reaction to four races; Kl, K2, K3 and K3a. Thirteen Tongil-type varieties and thirty-one Japonica varieties were resistant to only one race; K1. Nine Tongil-type varieties and one Japonica variety were resistant to two races; K1 and K2. One Tongil-type variety and twenty-eight Japonica varieties were resistant to the three races; K1, K2, and K3. Fourteen Tongil-type varieties and one Japonica variety were resistant to four races; K1, K2, K3, and K3a. A number of Tongil-type varieties showed broad spectrum resistance to four races, while a number of Japonica varieties showed broad spectrum resistance to three races; K1, K2, and K3.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.336-344
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• 2011

Using the abundant available information about the tomato genome, we developed DNA markers that are linked to disease resistant loci and performed marker-assisted selection (MAS) to construct multi-disease resistant lines and varieties. Resistance markers of Ty-1, T2, and I2, which are linked to disease resistance to Tomato yellow leaf curl virus (TYLCV), Tomato mosaic virus (ToMV), and Fusarium wilt, respectively, were developed in a co-dominant fashion. DNA sequences near the resistance loci of TYLCV, ToMV, and Fusarium wilt were used for primer design. Reported candidate markers for powdery mildew-resistance were screened and the 32.5Cla marker was selected. All four markers (Ty-1, T2, I2, and 32.5Cla) were converted to cleavage amplification polymorphisms (CAPS) markers. Then, the CAPS markers were applied to 96 tomato lines to determine the phenetic relationships among the lines. This information yielded clusters of breeding lines illustrating the distribution of resistant and susceptible characters among lines. These data were utilized further in a MAS program for several generations, and a total of ten varieties and ten inbred lines were constructed. Among four traits, three were introduced to develop varieties and breeding lines through the MAS program; several cultivars possessed up to seven disease resistant traits. These resistant trait-related markers that were developed for the tomato MAS program could be used to select early stage seedlings, saving time and cost, and to construct multi-disease resistant lines and varieties.

• Korean journal of applied entomology
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• v.12 no.4 s.17
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• pp.139-142
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• 1973

Experiment was conducted to study resistance of rice varieties and lines originated from Korea and IRRI-sources to the white-backed planthopper, Sogatella furcifera Horvath. The nature of varietal resistance to the insects was evaluated from the viewpoints of nymphal period and adult emergence. The varieties Colombia, Muthumanikam and Pankhari-203 were resistant, the varieties CO-22, Mudgo and Vellailangalayan moderately susceptible, the other varieties all susceptible. Nymphal period and rate of adult emergence were significantly different according to the degree of resistance of the rice varieties. Nymphal period was short (about 10 days) in the susceptible varieties and long (about 14-16 days) in the resistant varieties. The .ate of adult emergence was significantly lower in the resistant varieties than in the susceptible varieties. The lower rate of adult emergence in the resistant varieties may be due to the fact that the insects were suffered higher nymphal mortality in the resistant than in the susceptible varieties.