• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.278-285
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• 1998

Effects of chitosan on growth of tomato plant, and suppression of Fusaruim wilt caused by Fusarium oxysporum f. sp. lycopersici and late blight casued by Phytophthora infestans, were examined. Both late blight and fusarium wilt were suppressed by spray and irrigation of chitosan, respectively. Inhibition of mycelial growth was not greatly affected by molecular size of chitosan but, concentration dependent effects was observed. Ninty percent of P. infestans and 80% of F. oxysporum f. sp. lycopersici of mycelial growth was inhibited by 1,000 ppm of chitosan (MW 30,000~50,000) when amended in plate media. Induction of defense-related gene expression in plant by chitosan treatments were observed when chitosan treated tobacco and tomato RNA samples were hybridized with several defense-related genes as probes. The results revealed that $\beta$-1,3-glucanase and chitinase genes were strongly induced, while pathogenesis-related protein-1, 3-hydroxy-3-methylglutaryl coenzyme A reductase, anionic peroxidase, phenylalanine ammonia lyase genes were weakly induced by chitosan treatment. These results suggest that chitosan have dual effects on these host-pathogen interactions. Possible roles of chitosan in suppression of tomato diseases by inhibition of mycelial growth and activation of plant defense responses are discussed.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.96-102
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• 2020

Fusarium wilt caused by Fusarium oxysporum is a devastating disease limiting production of watermelon in Korea. The best way to control diseases is to use resistant gourd rootstock on watermelon. This study was conducted to establish an efficient screening method for resistant bottle gourd to Fusarium oxysporum f. sp. lagenaria. To develop an efficient inoculation method, incubation temperature after inoculation (15, 20, 25, and 30℃), inoculum concentration (1 × 10⁵, 5 × 10⁵, 1 × 10⁶, and 5 × 10⁶ conidia·mL^-1), and growth stages of seedlings (7, 10, 13, and 16 days) was investigated. Disease development of Fusarium wilt of bottle gourd was little affected by differences in incubation temperature and growth stages of seedlings. But resistant lines were more susceptible and appeared more severe symptoms at the higher inoculation level. Taken together, we suggest that an effective screening method for resistant gourd plant to Fusarium wilt is to dip the roots of 10-day old seedlings in spore suspension of 1 × 10⁵ - 1 × 10⁶ conidia·mL^-1, for 30 min, to transplant the seedlings into a non-infected soil, and then to incubate the inoculated plants in a growth room at 25℃ for 3 weeks to develop Fusarium wilt.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.645-648
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• 2010

A new spray carnation cultivar 'Lyra' was released by the National Institute of Horticultural and Herbal Science in 2003. A cross was made between spray cultivar 'Ballantyne' and red spray cultivar 'Chateau' in 1999. After investigation of the characteristics during four years (from 2000 to 2003), the cultivar 'Lyra' was finally selected in 2003. 'Lyra' is a spray cultivar with bright pink color for a cut flower. The main characteristics are early flowering, multi branching, fragrance and long flower stalk. Also, it has medium resistance to Fusarium wilt and 7 days vase life. To avoid calyx splitting caused by high temperature, it is recommended that this cultivar be grown over $8^{\circ}C$ at night and under $25^{\circ}C$ at day time during a flower bud differentiation period and applied with additional nitrate fertilization ($30.0kg{\cdot}10^{-1}$).

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.194-196
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• 2009

A new standard carnation Dianthus caryophyllus 'Pink Beryl' was bred from a cross of red standard cultivar 'Francesco' and purple standard cultivar 'Saturn' in 1996 at the National Institute of Horticultural & Herbal Science. After investigation of the characteristics for 4 years from 1997 to 2000 and registered to the official breeding variety of Rural Development Administration in 2000. 'Pink Beryl' is pink standard cultivar with round edge of petal for cut flower. It has medium resistance to Fusarium wilt. To avoid calyx splitting caused by high temperature, this cultivar is recommended to grow over $8^{\circ}C$ at night and under $25^{\circ}C$ at days during flower bud differentiation period.

• Korean journal of applied entomology
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• v.21 no.2 s.51
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• pp.61-67
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• 1982

The strawberry cultivar Hokowase showing rapid wilting and death around harvest time was first found in the fold at Woongcheon, Chungnam province in 1974. The fungus, Fusarium oxysporum was isolated frequently from the crown, petiole and root of strawberry plants collected from Woongcheon and was pathogenic to Hokowase. The fungus abundantly produced micro-and macro-conidia and chiamydospore on PSA. The size of micro conidia, macro conidia and Chlamydospores was $5.0\~13.0\times2.5\~3.0,\;12.8\~62.5\times2.5\times50\mu\;and\;7.5\~13.8\times5.5\~12.5\mu$, respectively. Mycelial growth of the fungus was best between $25\~30^{\circ}C$ on PSA. The disease at Woongcheon occurred from the end of March and incidence of the disease increased from the beginning of May reaching $40.2\%$ of diseased Plants at the 1st part of June. In laboratory and field evaluation tests with twelve fungicides, Difolatan, Benlate T and Tospin M showed some control effects against the disease although they did not show ignificant differences in effects compared with that of the non-treatment. The cultivar Yachiyo, Daehak 1, Line 10-2, and Senga Sengana were highly resistant, and Harunoka and Empire were moderate resistant whereas Northwest and Hokowase were highly susceptible to the fungus under field condition.

• Research in Plant Disease
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• v.24 no.3
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• pp.221-232
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• 2018

Rhizobacteria play important roles in plant growth and health enhancement and render them resistant to not only biotic stresses but also abiotic stresses, such as low/high temperature, drought, and salinity. This study aimed to select plant growth promoting rhizobacteria (PGPR) with the capability to mitigate biotic and abiotic stress effects on tomato plants. We isolated a novel PGPR strain, Variovorax sp. PMC12 from tomato rhizosphere. An in vitro assay indicated that strain PMC12 produced ammonia, indole-3-acetic acid (IAA), siderophore, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, which are well-known traits of PGPR. The aboveground fresh weight was significantly higher in tomato plants treated with strain PMC12 than in non-treated tomato plants under various abiotic stress conditions including salinity, low temperature, and drought. Furthermore, strain PMC12 also enhanced the resistance to bacterial wilt disease caused by Ralstonia solanacearum. Taken together, these results indicated that strain PMC12 is a promising biocontrol agent and a biostimulant to reduce the susceptibility of plants to both abiotic and biotic stresses.

• Research in Plant Disease
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• v.8 no.3
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• pp.146-161
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• 2002

Incidence of soilborne diseases, as a major cause of failure of continuous monocropping becomes severe in recent years. For examples, recent epidemics of club root of chinese cabbage, white rot of garlic, bacterial wilt of potato, pepper phytophthora blight, tomato fusarium wilt and CGMMV of watermelon are the diseases that require urgent control measures. Reasons for the severe incidence of soilborne diseases are the simplified cropping system or continuous monocropping associated with allocation of major production areas of certain crop and year-round cultivation system that results in rapid degradation of soil environment. Neglect of breeding for disease resistance relative to giving much emphasis on high yield and good quality, and cultural methods putting first on the use of chemical fertilizers are thought to be the reason. Counter-measures against soilborne disease epidemics would become most effective when the remedies are seeded for individual causes. As long-term strategies, development of rational cropping system which fits local cropping and economic condition, development and supply of cultivars resistant to multiple diseases, and improvement of soil environment by soil conditioning are suggested. In short-term strategies, simple and economical soil-disinfestation technology, and quick and accurate forecasting methods for soilborne diseases are urgent matter far development. for these, extensive supports are required in governmental level for rearing soilborne disease specialists and activation of collaborating researches to solve encountering problems of soilborne diseases.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.3-3
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• 2023

우리나라 딸기는 시설재배 발전과 품종개발로 겨울을 대표하는 과일로 변신하였다. 이는 저온단일에서 꽃이 만들어져 착과되는 생태적(일계성)특성 때문이다. 우리나라의 딸기 정식기는 95%이상이 촉성작형으로 9월 중순 정식한 후 11월 하순부터 이듬해 5월 하순까지 약 6개월간 수확한다. 반대로 여름작형은 고온장일에서 꽃이 만들어져 착과되는 사계성 품종을 이용하는데 우리나라 500m 이상의 산간 고랭지에서 3-4월에 정식한 후 6월부터 11월까지 수확하지만 생산량은 전체의 0.3% 미만이다. 또한 여름딸기는 제과용으로만 사용되고 있어 6월부터 11월 사이에 신선딸기의 단경기가 발생된다. 이러한 문제를 재배적으로 해결하기 위해 일계성 품종을 이용하여 겨울부터 봄까지 포기냉장한 후 여름과 가을에 꺼내어 정식하면 45일 내외에 수확하는 주냉장 억제작형을 시도하였으나 우리나라에선 실용성이 떨어져 사라져간 기술이다. 그러나 네덜란드는 우리나라와 같은 주냉장기술을 활용(Waiting bed system, Table top system)하여 여름과 가을철에도 딸기를 생산하고 있다. 이 작형은 냉장기간이 길고 재배기술도 까다로울 뿐만아니라 1화방만 수확하여 수량성이 낮은 단점이 있다. 한편 미국에서는 일계성 품종이 품질은 좋으나 고온기에 꽃대발생이 어렵고 사계성은 품질이 떨어지는 단점을 극복하기 위해 일장의 길이와 관계없이 꽃대가 형성되는 중일성 딸기 품종을 보급하여 세계적으로 가장 많은 재배면적을 점유하고 있다. 연중생산이 가능한 중일성 품종을 개발하기 위해 먼저 유전자원을 수집하였고 품질이 좋은 일계성 품종을 중일성 품종과 교배하여 채종하였다. 교배종자를 파종하여 묘를 만든 후 정식하여 실생개체를 선발한 결과 고온장일 조건에서 개화되는 사계성(중일성)율은 약 10-20% 범위로 매우 낮았다. 선발된 우량계통은 영양번식을 통해 증식하여 생산력, 특성, 지역적응성 검정과정을 통해 품종을 개발하였다. 이렇게 단교잡에 의한 중일성 품종 선발육종은 선발율이 0.05%으로 매우 낮았다. 이렇게 우리나라 최초의 중일성딸기 '고슬' 품종이 개발되었다. 이 '고슬'은 9월부터 수확이 가능한데 이 때의 딸기 가격이 kg당 20,000원 이상으로 높으며, 수확기간은 '설향'보다 4개월 더 길게 재배가 가능하다. 연중재배를 위해서는 항상 8-25℃의 범위을 유지해야 품질이 높아지므로 재배관리가 중요하다. 흰가루병에는 저항성이 있으나 시들음병과 탄저병에는 약하고 당도와 경도가 높고, 향이 매우 진하다. 식물공장에서 매우 인기가 있는데 안정된 꽃대발생과 대과, 고당도와 함께 수술의 화분량이 많아 수정이 잘되는 특성으로 식물공장 사업이 확장되고 있는 중동나라에서도 로열티 계약(UAE 등)이 예정되어 있다. 1년 연중 개화되고 착과되는 특성으로 가정에서 기르는 반려식물로도 인기가 있다. 또한 아열대 고랭지대는 항상 서늘한 날씨이기 때문에 한번 정식후 1년 연중생산이 가능하여 2023년 베트남과 로열티 계약(1.6억원)을 하였다. 또한 '고슬'은 우리나라 신선딸기 수출 단경기에 생산되어 주년생산 수출체계에도 기여할 것으로 본다.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.497-503
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• 2018

A strawberry variety 'Arihyang' was derived as an artificial cross between 'Tochiotome' and 'Seolhyang' in 2014. The seedling and line selections were conducted from 2014 to 2015. Preliminary and advanced yield trials of '14-5-5,' which was the final selected line, were conducted from 2015 to 2017. 'Arihyang' is suitable for forced cultivation and has strong plant vigor, uniformly large-sized fruit, and a high yield compared to those of the check variety, 'Seolhyang' and 'Maehyang.' Especially, vitamin C was at a significant level, which was approximately 15% higher than that of 'Seolhyang.' The average number of flowers per first flower cluster was 10.5, which could reduce the labor of thinning fruit. Its fruit has a conical shape, dark red color, and glossy skin. The fruit was of good quality but has recommendations for harvest at the fully ripened stage. 'Arihyang' has intermediate resistant to phytophthora crown rot, but is susceptible to powdery mildew, gray mold, anthracnose, and fusarium wilt. It is reguired to manage major diseases and pests using optimum cultivation techniques and chemical control.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.70-82
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• 2015

This study was conducted to establish an efficient screening system to identify melon resistant to Fusarium oxysporum f. sp. melonis. F. oyxsporum f. sp. melonis GR was isolated from infected melon plants collected at Goryeong and identified as F. oxysporum f. sp. melonis based on morphological characteristics, molecular analyses, and host-specificity tests on cucurbits including melon, oriental melon, cucumber, and watermelon. In addition, the GR isolate was determined as race 1 based on resistance responses of melon differentials to the fungus. To select optimized medium for mass production of inoculum of F. oxysporum f. sp. melonis GR, six media were tested. The fungus produced the most spores (microconidia) in V8-juice broth. Resistance degrees to the GR isolate of 22 commercial melon cultivars and 6 rootstocks for melon plants were investigated. All tested rootstocks showed no symptoms of Fusarium wilt. Among the tested melon cultivars, only three cultivars were susceptible and the other cultivars displayed moderate to high resistance to the GR isolate. For further study, six melon cultivars (Redqueen, Summercool, Superseji, Asiapapaya, Eolukpapaya, and Asiahwanggeum) showing different degrees of resistance to the fungus were selected. The development of Fusarium wilt on the cultivars was tested according to several conditions such as plant growth stage, root wounding, dipping period of roots in spore suspension, inoculum concentration, and incubation temperature to develop the disease. On the basis of the test results, we suggest that an efficient screening method for melon plants resistant to F. oxysporum f. sp. melonis is to remove soil from roots of seven-day-old melon seedlings, to dip the seedlings without cutting in s pore s uspension of $3{\times}10^5conidia/mL$ for 30 min, to transplant the inoculated seedlings to plastic pots with horticulture nursery media, and then to cultivate the plants in a growth room at 25 to $28^{\circ}C$ for about 3 weeks with 12-hour light per day.