• Weed & Turfgrass Science
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• 제2권3호
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• pp.306-311
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• 2013

Pythium aphanidermatum에 의한 잎마름병(pythium blights)이 chewing fescue "Jamestowm II" 품종에서 2011년 6월 상순에 대구대학교 시험포장에서 발생하였다. 잔디에 발병증상은 잎 끝으로부터 잎마름 증상과 뿌리 썩음증상이 나타나고, 잎색은 진한갈색,회 갈색으로 나타났다. 병원균은 병든 잎과 지제부에서 분리를 하였으며, 동정을 위하여 PDA에서 배양하였다. 균사에는 잎 같은 포자가 복잡한 구조로 부풀어져 있고, 균사로부터 구별되지 않은 실같은 포자낭이 있다. 리보소옴 DNA의 염기서열을 분석한 결과, 유전자은행 DB에 P. aphanidermatum 균주 와의 100% 상동성을 나타낸다는 것을 확인하였다. 병원성은 chewing fescue, creeping bentgrass 및 Kentucky bluegrass에서 코흐의 원칙에 따라 확인하였다. 이것은 chewing fescue 종에서 P. aphanidermatum 에 의한 잎마름병을 국내에서 처음보고 한다.

• The Plant Pathology Journal
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• 제22권1호
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• pp.1-6
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• 2006

The population shifts of Monilinia fructicola isolates which were resistant to the fungicide benzimidazoles were investigated in four regions of Korea from 1998 to 2000. The isolation frequency of benzimidazole-resistant isolates ranged from 18.8% to 29.6% in Chongdo and from $22.0\%$ to $26.8\%$ in Gyeongsan during the same period. However, the frequency of benzimidazoleresistant isolates was less than $4.0\%$ in Chochiwon and Youngduk during the same period. Benzimidazoleresistant isolates showed cross-resistance among benzimidazoles. On the other hand, none of the isolates showed cross-resistance to diethofencarb and carbendazim. Regardless of the year, the benzimidazole-resistant isolates of $EC_{50}$ higher than 500 $\mug%$ a.i./ml were isolated more frequently in mid and late season than in early season. In an orchard of Gyeongsan that had not been exposed to any fungicides for several years, the population of benzimidazole-resistant isolate had persisted without much fluctuation for three years. These results suggest that benzimidazole resistance of M. fructicola is becoming a problem in controlling brown rot and blossom blight of peach in regions like Chongdo and Gyeongsan.

• 한국식물병리학회지
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• 제14권3호
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• pp.260-267
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• 1998

This study was undertaken to find a new formulation of soil amendment, and selection of antogonists and to effectively control brown and large patch of turfgrasses caused by Rhizoctoniz solani AG1-1 and AG 2-2. Fourteen inorgainc chemicals (1%, w/w) were added individually in vitro, and some chemicals showed suppressiveness to R. solani. Alum suppressed effectively mycelial growth of R. solani in the range of 17 to 77% as compared with control. The four chemicals such as Al2(SO4)3, alum, CaO, and NH4NO3 were finally selected. Out of three organic compounds, composted pine bark (CPB) showed prominent suppressive effect as compared with milled alfalfa and pine leaves. After inoculation of R. solani isolates AG-1 and AG2-2 on the turf seedlings, water soaked lesions and blight symptoms were developed on the whole seedlings. According to inhibition zone method, mycelial growth of the fungus were greatly suppressed by culture filterates of the antagonists, Gliocladium virens (Gl1-) and Pseudomonas sp. (P713). CPB soil amendment mixed with antagonists (1% w/w) controlled not only brown and large patch of turfgrasses, but also promote the good growth of the seedlings. In addition, the controlling effect was maintained more than 30 days. Especially, the controlling effect of two antagonists was similar to Cㅖㅠ soil amendment with the antagonists and also stimulated a favorable growth of the seedlings. Therefore, its is expected that continuous control of Rhizoctonia blight of turfgrasses can be obtained in field by subsequent applications of the antagonists.

• 한국자원식물학회지
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• 제19권6호
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• pp.692-696
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• 2006

This study was conducted to evaluate the effect of seed disinfectant, in control of brown leaf blight, growth characteristics, and dry root yield in the cultivation of Alisma plantago after early maturing rice cropping. Experimental plot was laid out in split plots design with three replications. The major seed disinfectants were benomyl Wp, 20%, Captan Wp, 50%, Triferine Ec, 17%, Etridia zole Ec, 25%, and Thioplant-mythyl Wp, 50%. Even though seed disinfectant treated had no effect on the growth and flowering date of Alisma plantago, dry root yield was increased largely with benomyl Wp, 20%, in seed disinfectant than in the other seed disinfectants and contorl. All seed disinfectants had no injury with standard dosage. But all seed disinfectants had slight injury in the double dosage level for the Alisma plantago. On the basis of yield, vegetative and disease paramerer, benomyl Wp (20%) ($100g/20{\ell}$) had shown superior performance, however, all the seed disinfectants are effective as compare to without treatment.

• 아시안잔디학회지
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• 제13권1호
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• pp.55-66
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• 1999

Effect of an antagonistic bacterium AF-2001, Pseudomonas cepacia, on control of turfgrass diseases as brown patch, Pythium blight, dollar spot, and large patch were evaluated in vitro and in vivo. Results obtained in this study are summarized as follows. 1. Pseudomonas cepacia AF-2001 showed antagonism against to the pathogens causing brown patch, Pythium blighe, dollar spot and large patch. Especially, the biological agent showed strong antagonistic effect on the causal pathogens of brown patch, dollar spot, and anthracnose, but weak on Pythium blight 2. Populotion density of P. cepacia AR-2001 decreased ra;idly in turfgrass soils. Initial population of the agent was 2.4$\times$107 cfu/g soil, however, decreased to 1.4$\times$103, 6$\times$102 and 0 cfu/g soil on 10, 20, and 30 days after application, respectively. 3. Under the controlled controlled conditions of $27^{\circ}C$ and 95% RH, P. cepacia AR-2001 showed 100% control efficacy on brown patch either by pre-treatment or post-treatment of infection. However, Pythium blight was controlled about 94% by pre-treatment and only 29% by post-treatment 4. In field trials, P. cepacia AF-2001 did not suppress large patch and the control efficacy on other turfgrass diseases was lower than agro-chemicals such as tebuconazole and metalaxyl. Control efficacy of brown patch, Pythium and dollar spot by the biological agent was 57.4%, 40.4%, 61.5~87%, respectively. 5. Growth, color and texture of creeping bentgrass were not differ significantly between AF-2001 treatment and untreated control.

• The Plant Pathology Journal
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• 제21권1호
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• pp.77-82
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• 2005

A summer annual weed of monochoria (Monochoria vaginalis) grows in the edges of rice paddies, ditches, and moist upland throughout Korea. It is very difficult to control with herbicide because of its sulfonylurea resistance. It is very competitive with fast growing pattern, that can cause reducing yields of rice. Brown leaf blight of monochoria (Monochoria vaginalis) occurred naturally in rice paddy, is first reported in Korea. The fungal isolate BWC01-54 was successfully isolated from the diseased leaves of monochoria. The fungus BWC 01-54 was grown well at $25-28^{\circ}C$, conidia of the greysh black brown mycelia were abundant produced on PDA at 15 days. The fungus was grown well in potato dextrose broth at $28^{\circ}C$ and fully grown within 10 days in 250 ml of flask. In host and pathogenicity test, conidia suspension of BWC01-54 was the most effective to control of monochoria compare to others isolates. Typical symptoms having pin point brown lesions were formed on stem and leaf and which severely affected the whole plants ware blighted within two weeks, respectively. Under paddies field condition, conidial suspension of the fungus BWC01-54 gave around 90% control. Therefore, we conclude that the fungus may have a potential as a biological control agent against sulfonylurea resistance weed in rice paddy.

• 한국잠사곤충학회지
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• 제37권1호
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• pp.86-91
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• 1995

축엽세균병으로 알려진 피해뽕나무에서 진균인 Fusarium spp. 균이 분리되어 이를 구명하고 그 피해정도를 조사한 결과 1. 신소썩음증상은 세로로 긴 갈색의 병무늬가 시간이 경과할 수록 암갈색으로 변하고 흰곰팡이가 생기며, 축엽세균병증상은 잎이 말리고 신소에 수침상의 병반과 bacterial ooze가 보인다. 그러나 시간이 경과하면 구분이 어렵다. 2. 신소썩음증상의 피해율은 7.5%, 축엽세균병의 피해율은 4.4%였다. 3. Fusarium spp. 균의 분리는 신소썩음증상에서 높았고, Pseudomonas균의 분리는 축엽세균병 증상에서 많았다. 또한 병원성도 같은 경향을 보였다. 4. 수원 등 3지역 모두에서 부위별 병원성 Fusarium spp. 균의 분리율은 병반에서 30cm 부위에서 보다 병진전부위에서 더 높았다. 5. 수원 등 3지역 모두에서 개량뽕의 신소썩음증상 피해가 가장 많았다. 그러나 청올뽕의 신소썩음증상 피해는 조사 품종중에 가장 적었다.

• 식물병연구
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• 제11권1호
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• pp.77-79
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• 2005

2002년 전북지방에 야생하는 칡의 잎에 잎마름병이 발생하였다. 병징은 잎과 어린 줄기에 발생하고 잎에 처음에는 수침상 병반이 나타나고 잎의 가장자리 부분부터 갈색을 띠면서 안쪽으로 말라 들러가기 시작하였다. 병이 진전되면 잎과 어린 줄기는 갈변하며 낙엽 되었다. 병원균은 PDA에서 기중균사를 형성하고, 처음에는 흰색을 띠다가 연한 갈색으로 변하였다. 균사는 $90^{\circ}$로 분지하고, 대부분 하난의 세포에 다핵을 형성하였다. 또한 PDA에서 부정형 또는 타원형으로 0.5~3.0mm의 균핵을 형성하였다. 본 연구에서 칡의 잎에 마름병을 일으키는 병원균의 균학적 특징 및 형태적 특징을 조사한 결과, Rhizoctonia solani Kuhn에 의한 칡 잎마름병으로 명명하고자 제안한다.

• The Plant Pathology Journal
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• 제37권4호
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• pp.329-338
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• 2021

Alternaria leaf blight is one of the most common diseases in watermelon worldwide. In Korea, however, the Alternaria species causing the watermelon leaf blight have not been investigated thoroughly. A total of 16 Alternaria isolates was recovered from diseased watermelon leaves with leaf blight symptoms, which were collected from 14 fields in Korea. Analysis of internal transcribed spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and RNA polymerase II second largest subunit (RPB2) were not competent to differentiate the Alternaria isolates. On the contrary, analysis of amplicon size of the histone H3 (HIS3) gene successfully differentiated the isolates into three Alternaria subgroups, and further sequence analysis of them identified three Alternaria spp. Alternaria tenuissima, A. gaisen, and A. alternata. Representative Alternaria isolates from three species induced dark brown leaf spot lesions on detached watermelon leaves, indicating that A. tenuissima, A. gaisen, and A. alternata are all causal agents of Alternaria leaf blight. Our results indicate that the Alternaria species associated watermelon leaf blight in Korea is more complex than reported previously. This is the first report regarding the population structure of Alternaria species causing watermelon leaf blight in Korea.

• The Plant Pathology Journal
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• 제22권4호
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• pp.375-380
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• 2006

In the survey from 1992 to 2000, twenty-eight parasitic diseases were observed in major apple producing areas in Korea. The predominant apple diseases were white rot(Botryosphaeria dothidea), Marssonina blotch(Marssonina mali), Valsa canker(Valsa ceratosperma), Alternaria leaf spot(Alternaria mali), and bitter rot(Collectotrichum gloeosporioides and C. acutatum). Apple scab that reappeared in 1990 after disappearance for 15 years was disappeared again since 1997. A viroid disease(caused by apple scar skin viroid) was newly found in this survey. The five diseases, fire blight(Erwinia amylovora), black rot(Botryosphaeria obtusa), scab(Cladosporium carpophilum), Monochaetia twig blight(Monochaetia sp.), and brown leaf spot(Hendersonia mali), which had once described in 1928 but no further reports on their occurrence, were not found in this survey. However, blossom blight(Monilinia mali), brown rot(Monilinia fructigena), and pink rot(Trichothecium roseum), which did not occur on apple after mid 1970s, were found in this survey.