• The Plant Pathology Journal
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• 제17권3호
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• pp.184-188
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• 2001

Phytophthora-induced diseases on citrus in Jeju island have been considered of minor importance because of the use as root stock of trifoliate orange, which is immune to Phytophthora. However, brown rot on fruit, which severely occurred in 1998 and 1999, has become a great threat to citrus production in the island. About one-half of the surveyed orchards were infected in 1998 and 4 out of 19 infected fields showed over 20% fruit infection rate. The disease was less severe in 1999, with an estimated infected area and total fruit reduction of 3,155 ha and 15,300 tons, respectively. Typical gummosis was also occasionally observed on cv. Shiranugi, which is mostly cultivated under plastic film houses. Two types of Phytophthora were consistently isolated from various plant parts, identified as P. citrophthora and P. nicotianae. The former was isolated from the aerial parts of the fruit, young leaf, and shoot in the fields. Meanwhile, the latter was only isolated from the basal stem showing gummosis in plastic film houses.

• 식물병연구
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• 제10권4호
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• pp.345-348
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• 2004

2001년과 2003년 경기도 여주시 관엽재배 농가에서 세이브리찌야자의 줄기에 암갈색의 불규칙한 모양을 가진 병반이 형성되며 병든 줄기를 타고 끈적끈적한 연갈색 내지 암갈색의 고무액이 흐르는 증상이 발생하였다. 심하게 괴사된 줄기의 조직 속에는 분홍색 내지 오렌지색의 분생포자퇴가 다량 형성되어 있었다. 병든 식물의 병반으로부터 병원균을 분리하여 균학적 특징과 병원성을 검정한 결과 Gliocladium vermoseni으로 동정되었다. 분생포자의 모양은 타원형이며 무색으로 크기가 3.2${\sim}$4.0${\times}$4.8${\sim}$6.0 ${\mu}m$이었고 균사생장은 $25^{\circ}C$와 $30^{\circ}C$에서 가장 좋았고 $35^{\circ}C$이상 에서는 생장이 급격히 억제되었다. 본 연구에서는 야자에 발생하는 Gliocladium vermoseni에 의한 분홍썩음병(가칭)으로 명명하고자 제안한다.

• 생물환경조절학회지
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• 제6권3호
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• pp.151-158
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• 1997

토마토‘Sunroad’품종을‘Anchor-T’, ‘Kagemushia’,‘Joint’및 Vulcan’등 4가지 다른 대목에 접목하여 뿌리썩음시들음병(Fusarium oxysporum Schl. f. sp. jycopersici Snyder et Hansen, race J$_3$)이 만연한 포장에 재배하여 이병율, 수량 및 과실의 품질을 조사하였다. 그리고 질소비료의 시용수준(10, 20 및 30kg.ha$^{-1}$)에 따른 생장, 과실의 성분 및 식물체의 무기성분함량의 변화도 아울러 조사하였다. 접목묘는 무접목에 비하여 제 1번 화방의 개화가 촉진되었다. 접목은 초장을 증가시켰고 질소 소비량이 증가할수록 초장과 줄기 직경은 더욱 증가하였다. 접목한 토마토는 이병 되지 않았으나 ‘Anchor-T’ 대목에 접한 것은 64.7%의 이병율을 나타내었다. 접목한 토마토는 기형과, 발육불량과 및 잿빛곰팡이병과의 발생비율이 무접목구에 비하여 현저히 감소하였다. 접목과 무접목 사이에 있어서 가욕성고형물, 당함량, ascorbic acid 및 organic acid의 함량차이는 없었다. 질소 사용량의 증가에 따른 변화도 없었으나 ascorbic acid는 질소함량이 증가할수록 감소하였다. 잎과 줄기의 무기성분함량은 대목의 종류 및 질소 사용량에 따른 차이를 보이지 않았다. 다만 질소 105당 30kg 시용구에서는 접목한 것이 잎의 N, Ca 및 Mg 함량이 현저히 높았다.

• The Plant Pathology Journal
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• 제17권2호
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• pp.101-105
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• 2001

A disease survey on the carnation (Dianthus caryophyllus L.) wilt was conducted during the high temperature period (June through August) and the low temperature period (February through May) in 58 greenhouses of its major cultivation areas, including Pusan, Kimhae, and Changwon in Korea from 1998 to 1999. The disease incidence was averaged 5.4% and 11.9% in the low and high temperature periods, respectively. Severe damage was found in summer with high incidences of around 50% in some greenhouses. Close examination of the symptoms and isolation of the causal agent revealed that there was a new disease different from Fusarium wilt caused by Fusarium oxysporum f. sp. dianthi, which was determined as the stub dieback caused by F. was cetermined as the stub dieback caused by F. graminearum (teleomorph : Gibberella zeae). The stub dieback symptoms involved brown rot of stem that started usually from the portion of cutting without discoloration of inner vascular tissues. Seven out of 38 isolates from the wilted plants were identified as F. graminearum, while the others as F. oxysporum f. sp. dianthi. Mycological characteristics of the stub dieback pathogen including colony color, absence of microconidia, and the shape of macroconidia, were consistent with F. graminearum previously described. This is the first report of the carnation stub dieback in Korea.

• The Plant Pathology Journal
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• 제26권1호
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• pp.80-82
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• 2010

A stem spot disease was observed on Gymnocalycium mihanovichii (Korean name: Bimoran), a scion of graftcactus, in major growing areas of Goyang and Eumseong, Korea during 2008 and 2009. Typical symptoms were initial blackish brown lesions produced mainly on areoles and scars of injured stem tissues, gradually becoming large black spots. A causal organism isolate CD2-7A isolated from the infected stems was identified as Alternaria alternata based on its morphological characteristics and confirmed by the DNA sequencing analysis of ITS, glyceraldehydes-3-phosphate dehydrogenase (gpd), and allergen Alt a1 (Alt a 1) genes. Artificial inoculation of the fungal isolate CD2-7A produced the same rot symptoms on the cactus stems, from which the same fungus was isolated and identified. This is the first report of the black spot caused by A. alternata in the grafted cactus.

• 한국식물병리학회지
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• 제14권4호
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• pp.325-330
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• 1998

On the basis of the fact that the pycnidiospore of Botryosphaeria dothidea, the causal fungus of apple white rot is a typical water borne spore, a method for quantitative analysis of pycnidiospore dispersal from the warts produced on the diseased apple tree stem was developed. The warts on which cracks developed either on or around them were cut off at the base, and shaked in the water for 4hours at 2$0^{\circ}C$, in which condition the maximum number of spores were released. The volume of shaking solution was calculated as 1 ml per one wart. At the end of shaking, Trio, a household detergent was added to the shaking solution to the concentration of 0.1%, and shaked for additional 10 minutes at 35$^{\circ}C$ to take off the spores attached on the glass ware. One milliliter of the spore suspension thus prepared were passed through transparent membrane filter (pore size : 3.0 ${\mu}{\textrm}{m}$), and the spores attached on the filter were counted under a microscope ($\times$200) after staining them with lactophenol supplemented with aniline blue. The results thus obtained were statistically consistent when at least 30 warts were used simultaneously in single shaking. This method can be applicable in the elucidation of ecology of sporulation and spore dispersal, and also in the screening of the sporulation inhibitor which can be used in the control of the disease by reducing the inoculum density.

• 한국약용작물학회지
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• 제24권4호
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• pp.294-302
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• 2016

Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, $NO_3$, and $P_2O_5$ content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.

• 식물병연구
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• 제20권1호
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• pp.50-53
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• 2014

2012년 태안백합시험장 포장에 재배중인 절화 백합에서 이상증상이 발생하였다. 처음 병징은 토양 지제부의 줄기가 물러지고 점차 위쪽으로 진전되면서 결국 잎을 포함한 식물체 전체 적가 빠르게 부패되었다. 병원균의 균사생육 적온은 $25^{\circ}C$이며 PDA상에 왕성하게 생장하였으며, 갈색의 균총과 검은색의 포자낭을 형성하였다. 포자낭경은 초기에 흰색에서 점차 회색으로 되었으며 포자낭을 균사 끝에 형성하였고, 폭은 $6-10{\mu}m$이었다. 포자낭은 처음에 흰색에서 나중에 검은색으로 되었고, 모양은 반구형으로 크기는 $87-116{\mu}m$이었다. 포자낭포자는 담갈색으로 단포이며, 구형 또는 타원형으로 대부분 불규칙하며, 크기는 $4-8{\mu}m$이었다. 이상과 같이 병원균의 균학적 특징, ITS 염기서열 분석, 병원성 검정 결과 본 병해는 Rhizopus oryzae에 의한 백합 무름병으로 명명할 것을 제안한다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.62-62
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• 2020

Ginseng is a shade-plant cultivated using shading facilities. However, at too low light levels, root growth is poor, and at high light levels, the destruction of chlorophyll reduces the photosynthesis efficiency due to leaf burn and early fall leaves. The ginseng has a lightsaturation point of 12,000~15,000 lux when grown at 15 to 20℃ and 9,500 lux at 25℃. This study was conducted to select the optimal light intensity of 3-year-old ginseng grown in blue-white film plastic house. The seeds were planted in the blue-white film plastic house with different light receiving rate (March 17, 2020). Between April and September, the average air temperature in the house was 20.4-20.7℃. Average soil temperature was 18.3℃-18.5℃. The chemical properties of the test soil was as follows. The pH level was 7.0-7.4, EC was 0.5-0.6 dS/m, OM was at the levels of 33.6-37.7 g/kg, P₂O₅ was 513.0-590.8 mg/kg, slightly higher than the allowable 400 mg/kg. The amount of light intensity, illuminance, and solar radiation in the blue-white film house was increased as the light-receiving rate increased and the amount of light intensity was found to be 9-14% compared to the open field, 8-13% illuminance and 9-14% solar irradiation respectively. The photosynthesis rate was the lowest at 3.1 µmolCO²/m²/s in the 9% light blue-white plastic house and 4.2 and 4.0 µmolCO²/m²/s in the 12% and 14% light blue-white plastic house, respectively. These results generally indicate that the photosynthesis of plants increases with the amount of light, but the ginseng has a lower light saturation point at high temperatures, and the higher the amount of light, the lower the photosynthetic efficiency. The SPAD (chlorophyll content) value decreased as the increase of light-receiving rate, and was the highest at 32.7 in 9% light blue-white plastic house. Ginseng germination started on April 11 and took 13-15 days to germinate. The overall germination rate was 82.9-85.8%. The plant height and length of stem were long in the 9% light-receiving plastic house. The diameter of stem was thick in the 12-14% light-receiving plastic house. In the 12% and 14% light-receiving plastic house, the length and diameter of taproot was long and thick, so the fresh weight of root per plant was 20 g or more, which was heavier than 16.9 g of the 9% light-receiving plastic house. The disease incidence (Alternaria blight, Gray mold and Damping-off etc.) rate were 0.9-2.7%. The incidence of Sclerotinia rot disease was 7.5-8.4%, and root rot was 0-20.0%. The incidence ratio of rusty root ginseng was 34.4-38.7% level, which was an increase from the previous year's 15% level.

• 한국미생물·생명공학회지
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• 제38권3호
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• pp.295-301
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• 2010

마늘병원균에 대한 토착길항미생물 선발을 위하여 경북 영천시 신덕리 및 구계리 일대 16개소의 토양 시료로부터 160균주의 세균들을 분리하였다. 이들 분리된 세균 중 마늘 잎집썩음병의 원인균인 P. marginalis와 마른썩음병의 원인균인 F. oxysporum에 대하여 길항능이 매우 뛰어난 3종의 토착길항세균을 선발하였다. 선발 균주들을 16s rDNA sequencing과 Bergey's manual을 이용한 방법에 의해 동정한 결과 B. subtilis YC82, B. vallismortis YC84, B. amyloliquefaciens YC240 균주들로 동정할 수 있었다. 선발된 3종의 토착길항세균들은 항세균 및 항진균 길항기작인 siderophore, ${\beta}$-glucanse, chitinase, 항생물질 생산능을 가진 균주들이었으며, 식물의 생장촉진에 도움이 되는 인산가용 화능과 식물생장촉진호르몬인 옥신 및 지베렐린을 생산하는 균주들로 확인되었다. 또한, 3종의 토착길항세균들은 in vivo 포트실험을 통해 잎집썩음병원균인 P. marginalis 에 대한 방제율이 70% 이상이고 동시에 생장촉진능도 있다는 것을 검증하였다. 그리고 마른썩음병원균인 F. oxysporum에 대한 방제율도 B. subtilis YC82와 B. amyloliquefaciens Y240의 경우 60%, B. vallismortis YC84는 80% 이상으로 나타났다. 또한, 발아촉진능에서는 선발된 토착길항세균의 처리구가 무처리구에 비하여 20% 이상 향상된 우수한 발아촉진능을 나타내었으며, 생장촉진능 역시 초장 길이의 차이에서 B. subtilis YC82는 평균 $49{\pm}1.53\;mm$, B. vallismortis YC84 는 평균 $47{\pm}1.15\;mm$, B. amyloliquefaciens YC240에서는 평균 $80{\pm}1.21\;mm$로 무처리구의 평균 $39{\pm}1.51\;mm$ 보다 매우 우수하였다. 이와 같은 결과는 선발된 마늘잎집썩음병 및 마른썩음병 방제용 토착길항세균은 마늘병원균 방제능과 동시에 생장촉진능을 가지는 다기능 토착길항세균으로 향후 추가적인 현장적용시험을 통하여 병방제능 및 생장촉진능 검증이 이루어 진다면 마늘병해방제 및 생장촉진용 미생물제제 개발이 가능할 것이라 생각된다.