• Research in Plant Disease
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• v.16 no.3
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• pp.290-293
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• 2010

Bacterial canker, caused by Clavibacter michiganensis subsp. michiganensis, is a very damaging disease to tomato (Lycopersicon esculentum) farm in Korea. It infects tomato, spreads through the xylem and causes bacterial wilt and canker. Selection of resistant cultivar is the best way to prevent or reduce the occurrence of the disease. Thirty-nine tomato cultivars, twenty-one cherry tomato cultivars and thirteen rootstock tomato cultivars were inoculated with Clavibacter michiganensis subsp. michiganensis, to evaluate tomato cultivarspecific resistance against bacterial canker. In the evaluation of 73 major commercial cultivars, 'Sunmyung', 'Sweet', 'Akiko', 'Dadaki', 'Match', 'Magnet', 'Friend', and 'Greenpower' were found to have a high level of resistance to bacterial canker of tomatoes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.302-309
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• 1987

One hundred rice varieties were tested for their level of resistance to sheath blight disease at adult plant stage in field condition through 1984 to 1986. Rice plants were grown under ordinary seasonal culture and inoculated by k-2 fungus isolate during three years. k -1 isolate was also inoculated separately in 1984 and test under late seasonal culture was conducted in separate field in 1985. Degree of damage by the disease observed at 25 days after heading was used to identify the level of resistance of the rice varieties tested. Varietal differences of degree of damage were significant in five tests during three years, and the genotypic variance of degree of damage was always higher than environmental variance among varieties tested. Positive correlations between testing years, between cultural seasons, and between isolates inoculated were found in degree of damage of varieties tested for two or three years continuously. Degree of damage by the disease was correlated negatively with heading date of rice varieties except 1984 tests. Thus, the level of resistance should be compared among the variety group having almost same heading date in field condition, and late and extremely late variety groups should be tested for their level of resistance under appropriate environmental condition. Gayabyo, an early heading variety, and SR9713-54-3, a medium heading breeding line, showed consistent lower value of degree of damage during two or three years. These two varieties were selected as moderate resistant germplasm.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.129-132
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• 2014

A new resistant cabbage variety 'CT-171' to Fusarium wilt was bred by crossing $A337MSBC_5$ with resistance to the disease and 397-$G_6$ with good density and color. 'CT-171' was selected after combining ability, seed gathering and regional adaptability test in 2008. For breeding of resistant varieties, we investigated the development of Fusarium wilt on cabbage seedlings inoculated with Fusariumoxysporum f. sp. conglutinans by root dipping inoculation method. As a result, 'CT-171' showed higher resistance to Fusarium wilt than 'Asiaball' used as control. The maturity of new variety was 58 days and was faster than control and well suited for autumn cultivation because of cold resistance. The anthocyanin pigment of plant was not revealed. The weight, height and width of head were 1.5 kg, 14 cm and 15 cm, respectively and the core size was 5.7 cm and stable in various cultivation environments. 'CT-171' which showed good agricultural character and resistance to Fusarium wilt filed for variety protect right in Korea Seed & Variety Service on February 2013. The new variety will be appropriate for export and domestic consumption.

• Korean journal of applied entomology
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• v.15 no.4 s.29
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• pp.163-168
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• 1976

The present study was conducted to determine the number of genes controlling resistance of variety Tongil to three prevalent blast strains and any relationships among the genes in the inheritance of resistance of the variety to blast. Tongil was crossed with five local varieties and the progenies were tested with blast isolates E-7 and 100-14 by injection inoculation method. Results indicated that a tingle dominant gene conditioned resistance of variety Tongil and resistance to the isolate E-7 was controlled by a gene different from that controlling resistance to the isolate 100-14. In previous study it was identified that the gene controlling resistance to the isolate E-7 was different from the gene for resistance to isolate T-1. Therefore based on the foregoing results it may be inferred that the variety Tongil has at least three or more resistant genes to blast.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.282-293
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• 2016

Root-knot nematodes (Meloidogyne spp.) are major plant pathogens that cause reductions in yield and quality of several solanaceous crops, including pepper (Capsicum spp.). These losses can be averted through planting of resistant cultivars. Plants are defined as resistant when they suppress nematode reproduction. In this study, the resistance degrees of 102 commercial cultivars of chili pepper (Capsicum annuum) to a root-knot nematode, Meloidogyne incognita, were evaluated by comparing the number of egg masses on their roots to those of 'PR huimangchan', a highly susceptible cultivar that exhibited the most egg masses of the chili pepper cultivars evaluated. Among these cultivars, forty-four (43.1%) showed resistance to M. incognita and eighteen (17.6%) were moderately resistant. The other cultivars (39.3%) were determined to be susceptible. For further study, six chili pepper cultivars (i.e., Gangryeokjosenggeon, Shinsegae, Muhanjilju, PR Bulrocho, PR Huimangchan, and Jjang) with different levels of resistance to the nematode were selected. Changes in resistance of the six cultivars under several conditions, such as inoculum concentration, plant growth stage, and cultivation period after transplanting were investigated. We found that an efficient screening method for resistance of chili pepper to M. incognita is to transplant the chili pepper seedlings 7 days before inoculation, to inoculate 28-day-old plants with M. incognita by loading 5,000 eggs per plant into the pot of soil, to cultivate the plants in a greenhouse ($25{\pm}5^{\circ}C$) for 45-60 days, to measure the number of egg masses on roots of the seedlings, and then to determine the resistance response of the plants by comparing the number of egg masses on the roots with a reference-susceptible cultivar 'PR huimangchan'.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.366-370
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• 2013

This experiment was carried out to establish the screening methods for the selection of Zantedeschia aethiopica cultivars resistant to calla lily soft rot caused by Pectobacterium carotovorum subsp. carotovorum. A center of leaf and petiole tissues of four Z. aethiopica cultivars were wounded and inoculated with three different inoculum concentrations, $1{\times}10^7cfu/mL$, $1{\times}10^8cfu/mL$, and $1{\times}10^9cfu/mL$, of EccNHRI-21 isolate. And they were evaluated at 4, 18, and 26 hours after inoculation. The lesion of maceration was developed well in the leaf tissues inoculated with $1{\times}10^9cfu/mL$ concentration. And evaluation of resistance in 18 hours after inoculation was correlated with field resistance positively. Using this method, ten Z. aethiopica commercial cultivars and four wild types were screened. 'Crowbrough' and 'White Cutie' were selected as highly resistant genotypes and 'Mont Blanc' and 'Silky White' as resistant genotypes. 'Wedding March' and 'Kiwi Blush' were evaluated as moderate resistant and the others including 'Childsiana' were susceptible. And all of four wild types were evaluated as more than moderate resistant. In spite of control through cultural, biological and chemical methods, the use of resistant cultivars is most efficient to overcome calla lily soft rot. This newly developed screening method was helpful for breeding new varieties resistant to calla lily soft rot.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.764-771
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• 2013

Recently, Cucumber mosaic virus (CMV)-P1 infection in pepper cultivation is very serious problem, which causes low marketability and yield. In this research, 56 domestic pepper cultivars including 20 PR (Phytophthora resistance) cultivars, 31 foreign pepper lines collected from USA and 112 genetic pepper resources form RDA Genebank were used for CMV-P1 resistance evaluation. Resistance evaluation was performed at 24 days and 51 days after artificial inoculation of peppers by enzyme-linked immunosorbent assay (ELISA). Among the 36 domestic cultivars 'Muhanjilju' were resistant to CMV-P1. All 20 PR cultivars and 29 foreign peppers except 'NuMex Twilight' and 'Chainese Giant' were susceptible. Among 112 pepper lines from RDA Genebank, nine pepper lines were resistant, and 17 pepper lines were moderately resistant, and 86 pepper lines were susceptible. Almost all domestic peppers on the market were highly susceptible to CMV-P1, whereas 17.2% of foreign pepper cultivars and genetic pepper lines from RDA Genebank were resistant or moderately resistant. Resistant pepper lines selected in this study can be used as genetic sources for breeding CMV-P1 resistant pepper.

• Korean journal of applied entomology
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• v.19 no.3 s.44
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• pp.156-162
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• 1980

The inheritance and varietal differences of resistance to bacterial leaf blight caused by Xanthomonas oryzae in rice were studied. Among eighteen cultivars used, 'IR2061-465-1-5-5', 'IR2061-552-6-9', 'IR 1561-228-9-3', ana 'Milyang42, were found to have a high level of resistance to the three isolates of X. oryzae at maximum tillering and flowering stage. Varietal differences in lesion development of the cultivars belonging to the same varietal group were clearly recognized. For the genetic study on bacterial leaf blight resistance, two rice breeding lines 'IR2061-465-1-5-5', 'IR1561-228-3-3' were crossed with susceptible cultivar 'Milyang 23'. The $F_1,F_2,\;and\;F_3$ progenies were evaluated at flowering stage using the bacterial isolate 'JN 7853'(II). Average lesion length of the $F_1$ plants of the crosses showed longer than that of resistant parents, and the frequency distribution of lesion length in the $F_2\;and\;F_3$ populations showed continuous variation.

• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.111-117
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• 2014

Phytophthora blight caused by Phytophthora capsici Leonian is a dangerous disease threatening pepper growers worldwide. The efficacy of chemical control is generally low as the pathogen is soil-borne and rapidly spread by zoospores during the rainy season. Thus, based on the demand for resistant varieties, various good resistant sources, such as CM334, AC2258, and PI201234, have been reported and their inheritance of resistance studied by many different authorities. However, the mode of inheritance remains unclear, as 1 or 2 independent dominant genes, 3 genes, or multiple genes have all been reported as responsible for resistance. Recently, QTL mappings of the gene factors for resistance have been reported, and molecular markers for resistance used in breeding programs. With the release of many resistant commercial hybrid cultivars, differentiation of pathotypes of the pathogen is attracting interest among breeders and plant pathologists. Various authorities have already classified the pathogen strains into different races according to the inter-action between resistant host plants, including the source of resistance, such as CM334 and PI201234, and resistant commercial varieties and P. capsici isolates. However, no standard differential host sets have yet been established, so the results are good only for the pathogen strains used in the experiments. Thus, for breeding varieties with durable resist-ance, it is important to introduce resistance from different sources and use diverse local pathogen strains collected in the target area for distribution in a breeding program.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.17-17
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• 2021

곰취는 주로 쌈용, 장아찌, 나물용 등으로 이용되고 있으며 주로 자생 곰취의 일종인 '곤달비' 라고 하는 종이 많이 재배되고 있다. 일반 곰취에 비해 곤달비는 향이 진하지 않고 씁쓸한 맛이 적어 인기가 많은 종이다. 또한 농가에서는 엽수가 많아 수량이 높기 때문에 재배를 선호하게 된 종이기도 하다. 그러나 곤달비는 수확후 여름을 지나면서 고온건조기에 흰가루병과 식물체가 위축되는 로젯현상으로 잎이 작고 진록색으로 되거나 고사하여 다음해의 수량을 저하시키는 원인이 되고 있다. 이렇게 2~3년 재배를 하면 연작장애와 더불어 결주가 생기기 시작하고 수량이 급격히 감소하는 문제가 발생되는 실정이다. 이러한 문제점을 해결하기 위하여 흰가루병에 저항성이면서 세력이 우수한 한대리곰취와 일반곰취를 교배하여 흰가루병에 강하고 수량성이 뛰어난 계통을 선발하여 그 동안 '쌈마니', '다목이', '곰마니', '수마니', '그린베어' 등 5품종을 육성한 바 있다. 이번에는 용도 다양화를 위하여 잎이 매우 커서 김밥처럼 곰취 밥말 이용을 선발하여 품종을 만들고자 하였다. '대마니' 품종은 2007년 7월에서 9월까지 인공교배를 하여 종자를 얻었으며 2008년 3월에 파종하여 육묘후 포장에 정식하여 생육관리를 하였다. 2013년 생육 및 수량특성 조사에서 일반적으로 많이 재배되는 '곤달비' 종보다 우수한 7033-1번 개체를 선발하였다. 선발된 7033-1번 개체는 2014년부터 2020년까지 노지포장에서 증식되면서 고농G-7호로 계통화 되었으며 2019년부터 2년간의 생육특성 검정을 통하여 최종 선발하였다. 그리고 2020년 농작물직무육성 품종선정위원회에서 신품종으로 선정되어 '대마니(Daemani)'로 명명되었다. '대마니' 품종의 특성은 엽병귀의 색이 연녹색을 띠고 엽병에 털이 있으며 잎 뒷면에 털은 없으나 광택이 없고. 엽맥밀도는 보통이다. 쌈용, 데침쌈용, 묵나물용으로 이용이 가능하다. 특히 엽장과 엽폭이 39cm와 49cm로 '잎이 커서 밥말이용으로 적당하다. 주당 엽수는 54개로 '쌈마니' 품종보다 매우 적다. 주당 수량은 4,961g 으로 '쌈마니' 1,362g 보다 3배 정도 많았다. 추대시는 8월 28일, 개화시는 9월 16일로 '쌈마니' 품종보다 약 6일 정도 늦었다. 흰가루병 저항성 정도는 '쌈마니' 품종의 중도 저항성에 비하여 전혀 병에 감염되지 않는 강한 저항성을 보였다. 이와 같은 특성의 흰가루병 저항성 품종이고 잎이 큰 '대마니' 품종이 농가에 보급되어 출하된다면 밥말이용 등 용도다양화를 통한 새로운 소비창출이 가능할 것으로 기대된다.