• Korean journal of applied entomology
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• v.11 no.1
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• pp.15-18
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• 1972

한국의 도열병검정못자리에서 고도로 저항성인 공시한 20개의 IR계 수도가 핀립핀 IRRI(국제미자연구소)에서는 모두 이병성이었으나 9계통의 IR1317중에서 7계통만은 저항성이었다. 한편 20개의 IR계는 한국의 도열병균 레이스, 5개의 IG-1, 3개의 IH-1, 각각 한개의 IC-3, IC-4에도 모두 저항성이었으나 필립핀 레이스, 5개의 $P_8$,각각 한개의 $P_2,\; P_{87},\; P_{150}$에 대하여는 몇 가지 예외를 제하고 모두 이병성이었다. 그리고 도열병검정못자리에서나 각 레이스에 대한 온실검정에서 대조품종인 진흥은 IR계 수도와는 달리 한국에서는 이병성이었으나 IRRI에서는 저항성이었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.2
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• pp.129-133
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• 2007

To breed virus resistant rice variety, developing an efficient screening method is the most important. Two screening methods such as field screening and tray screening method have been used, but the efficiency of the field screening method is too low because of environment factors and the that of the tray screening method is good but screening capability is limited with only $200{\sim}300$ lines per year. To overcome those problems, mass screening method using screen house was developed. Barely as host plant of vector insect was grown in screen house in winter season. Then viruliferous insects are spread in the first spring of the initiation year and sustain them annually. Screening of virus resistance was tested two times in a year, the first screening was from April to June and the second from July to September. The virus infected rate of each susceptible varieties was increased to 92% for RSV and 100% for RDV from the second year. Also, this method can evaluate as many as $1,500{\sim}2,000$ pedigree lines in one time compared with the tray screening method. The result indicates that the mass screening method using screen house, which combines the advantages of the field and tray screening methods, is proven to be more efficient and reliable.

• Research in Plant Disease
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• v.22 no.3
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• pp.152-157
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• 2016

Root-dipping inoculation method has been used to investigate resistance of radish plants to Fusarium wilt. However, the method requires a lot of labor and time because of complicate procedure. This study was conducted to establish a simple and effective mass-screening method for resistant radish to Fusarium wilt. Radish seedlings of susceptible and resistant cultivars were used to investigate wounding method by scalpel, inoculum concentration, and pathogen-inoculated growth stage of seedlings. We established an efficient mass-screening method based on our results as following: Roots of 14-day-old seedlings of radish are cut with a scalpel at a $90^{\circ}$ angle to a 2 cm-depth at a 1 cm-distance from main stem and then inoculated by pouring with a 10 ml-aliquot of a fungal spore suspension ($1.0{\times}10^7conidia/ml$) on soil. The inoculated plants are cultivated in a growth room at $25^{\circ}C$ for about 4 weeks with 12-hour light a day. The proposed screening method enables to effectively select resistant from mass radish plants cultivars to Fusarium wilt.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.394-400
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• 2017

This study investigated whether culture filtrates produced by Xylella fastidiosa can be used to determine the varietal susceptibility to Pierce's disease in grapevines (Vitis spp.) as a substitute for pathogen inoculation or field screening. A bioassay of grape leaves with culture filtrates from the pathogen showed that their phytotoxicities were active and host-selective. Ethyl acetate extracts from them also showed toxicities and host selectivity in both bunches of grapes and muscadine grapes. The sensitive range of plants to the culture filtrates and their ethyl acetate extracts was consistent with the host range of the Pierce's disease pathogen. Susceptible cultivars are sensitive to even highly diluted culture filtrates, while resistant cultivars were not affected even at their original culture filtrates. Susceptible cultivars were more sensitive to the undiluted culture filtrate than were highly diluted culture filtrates, and the younger leaves were the most sensitive to the culture filtrates in grapes. Although some European grape cultivars showed moderately susceptibility in this study, the determination of varietal resistance to Pierce's disease by the treatment of culture filtrates of pathogens could provide valuable information for the preliminary selection of genetic resources and seedlings from hybridization in a disease resistant grape breeding program.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.65-70
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• 1999

This study was conducted to develop a simple selection method for herbicide-resistance weeds. Two methods, designated "seedling method" and "stem node method" were employed for screening of barnyardgrass against propanil and butachlor. In the seedling method, shoot and root growth of barnyardgrass were significantly inhibited at quarter of the recommended herbicide rate, while in the stem node method, the similar inhibition was obtained at half of the recommended rate. Thus, it was concluded that the seedling method is more simple and quick method to evaluate response of barnyardgrass to propanil and butachlor compared to stem node method.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.394-400
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• 2008

Blast resistance of one hundred and thirty-one rice cultivars bred in Korea was tested with thirty Korean isolates and twenty-two Philippines isolates using three screening methods. In the blast nursery conducted in Korea and in the Philippines, average disease index of rice cultivars were 4.6 and 2.2, respectively. Seventy-nine cultivars showed different resistance reaction in Korea and in the Philippines, and 19 cultivars showed the same resistant reaction in two locations. In the seedling test, Korean blast isolates displayed different levels of virulence. 93-093, a Korean isolate, was compatible with 90 cultivars whereas 97-057 showed a compatible reaction with 13 cultivars. Twenty-three cultivars showed high level of resistance against Korean and Philippines isolates but Chucheongbyeo, Heugnambyeo, and Manmibyeo showed susceptible reaction to all blast isolates. Through the sequential planting test in Korea and in the Philippines, Palgongbyeo and Seomjinbyeo displayed durable resistance, and Nagdongbyeo and Gihobyeo showed high level of disease infection over the planting time. These results indicate that blast isolates collected in two countries have different genetic background and number of compatible isolates should be considered in definition the durability of rice cultivar to rice blast.

• Research in Plant Disease
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• v.16 no.3
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• pp.279-284
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• 2010

Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of $4.0{\times}10^8$ spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days, and then cultivated in a greenhouse ($25{\pm}5^{\circ}C$) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease.

• Research in Plant Disease
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• v.21 no.3
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• pp.243-249
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• 2015

Soybean frogeye leaf spot caused by the fungus Cercospora sojina Hara, has known to lead a severe reduction of crop yield. Since frogeye leaf spot on soybean has recently become a serious problem in Korea, the susceptibility of recent recommended cultivars against C. sojina had been tested. To standardize the disease severity of soybean, the optimum sporulation condition of C. sojina and the disease index were established in this study. Sporulation was maximized on the 10% V8 juice agar with 12 h light and 12 h dark at $25^{\circ}C$. Spore suspension ($10^5spores/ml$) was sprayed on the leaves of soybean (V6 stage), and the disease responses to each isolate were evaluated on 28 days after inoculation. As a result, Daepung, Shinpaldal2ho, Yeonpung and Cheonga showed the resistance reaction to 8, 7, 6, 6 isolates of C. sojina, respectively, whereas Cheongja, Hwangkeum, Taekwang, Daewon, Cheonsang and Sinhwa showed the susceptible reaction to 8 isolates of C. sojina. Breeding the resistant soybean cultivars against C. sojina requires a uniform resistance for screening technique. The disease index of frogeye leaf spot on soybean developed in this study can be effectively used for the accurate field assay to select the frogeye leaf spot resistant soybean.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.9-18
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• 2002

A total of 31 C. chinense lines selected from 2000 screening were tested again for resistance to P. capsid but resistance was not found in tile lines. A total of 26 selections from Korean land races tested 2001 spring were tested again for resistance to P. capsici, KC180, KC230, KC195 and KC194 showed moderate resistance to P. capsid. However, it was apparent on the basis of horticultural characteristics that KC180 and KC230 had been naturally crossed with AC2258 and CM334, respectively. CM334 and AC2248 seed lots that were increased in different years were taken out and tested for resistance to improve their genetic purity because the resistant genetic resources have been showing some off-types in tile population. Off-types began to be found in 1992 seed lots and tile proportion and degree of tile offs was increasing with time up to 2001. Plants true to the type in 1992 seed lots were selected and their inbred seeds were mass produced in a net cage in the greenhouse. AC2258 included in the experiment together was uniform. In 1995 seed lots of CM334, plants with resistance to P. capsici and low or no number of lateral branching at cotyledonary axil, although they were off from tile original CM334, were found and selection was applied to breed lines fixed in tile characters.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.48-51
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• 1986

Resistance to the flacherie virus(FV) and the densonucleosis virus(DNV) of 10 Japanese lines and 10 Chinese lines used for hybrids was tested and the results obtained are as follows ; 1. Hansang #1 showed the highest resistance to the FV among the tested Japanese lines whereas Mudeung was of lowest resistance. In Chinese lines tested on the resistance to the FV, Jam118 was the highest while Jam 116 was the lowest. 2. In Japanese lines tested on the resistance to the DNV, it was shown that Jam 117, Gyeongchy, Mudeung, Hansaeng #1 and Hansaeng #3 were of the complete resistance but Jam 115 showed the lowest resistance. On the other hand, all the Chinese lines tested showed the complete resistance to the DNV.