Phytophthora cryptogea에 의한 거베라 역병

지형진,김완규,이상엽,조원대 한국식물병리학회 1996 Plant Pathology Journal Vol.12 No.3

1992년부터 국내 주요 거베라 재배지역에서 Phytophthora속 균에 의한 역병이 발생하였다. 이병주는 뿌리조직이 파괴되어 급격히 시들며 말라죽는데 지제부의 잎자루는 수침상으로 검게 썩는 병징을 나타낸다. 총 47개 균주를 이병주에서 분리하여 균의 형태적, 배양적, 생리적 특성 등을 조사한 결과 모두 Phytophthora cryptogea로 동정되었다. 각 지역에서 수집된 20개 균주중 유성생식형 A1과 A2는 각각 8균주와 4균주였고 8개 균주는 불임성(sterile)이었다. 병원균은 7개 거베라 품종에 모두 강한 병원성을 나타내어 품종간 차이를 관팔할 수 없었다. P. cryptogea는 아직 국내에 기록된 바가 없는 식물병원균으로 거베라 역병균으로 처음 보고한다.

고추 탄저병균(Colletotrichum acutatum)의 분생포자 비산과 과실병반에 형성된 전염원 밀도

지형진,신순선,이지현,김원일,홍성준,김용기 한국식물병리학회 2010 식물병연구 Vol.16 No.1

본 연구는 고추 탄저병균인 Colletotrichum acutatum의 강우에 따른 비산량과 비산거리 및 포장에서 감염 후 병증상의 발현시기 그리고 병반에 형성된 전염원의 밀도 등을 알아보기 위해 수행하였다. 고추탄저병균의 분생포자는 비가 오는 날에 99.2%가 비산되었고 맑은 날에는 단지 0.8%의 포자만이 비산하였다. 포자의 비산량은 전염원과의 거리와 정의 상관이 있었다. 고추 탄저병균 포자의 93.3%는 전염원과 30cm 수평거리에서 60cm 높이 이하로 전파되었으며 120cm 높이까지 비산하는 것으로 조사되었다. 노지에서 상대적으로 감수성이 높은 품종의 고추 과실과 낮은 품종의 과실은 각각 4일과 6일 후에 최초로 외부 병 증상을 나타내었다. 하지만 10일 후에 병증상을 나타내기도 하여 기상환경에 따라 병원균의 잠복기간이 10일 이상일 가능성도 있을 것으로 판단되었다. 고추 병반에 형성된 전염원인 분생포자의 수는 병방의 크기가 클수록 많았는데 병반의 길이가 1.5 cm 이상일 경우에는 병반 당 천만 개 이상의 포자가 형성되었으며 여러 개의 병반이 합쳐져 병반 길이가 4cm가 넘을 경우 1억개가 넘는 포자가 형성되기도 하였다. 이상의 결과로 고추 탄저병균인 C. acutatum이 빗물에 튀어서 전파되고 비바람의 강도에 따라 상당히 먼 거리로 전파될 수 있으며 기상환경에 따라 감염 후 10일 이상의 잠복기를 가질수 있으며 한 개의 큰 병반에는 수 천만개의 전염원이 형성되는 것을 확인되었다. 따라서 고추 탄저병의 가장 효과적인 방제수단은 빗물을 직접 맞지 않도록 하는 비가림 시설이며, 노지에서는 병든 과실을 조기에 제거하고 병 발생 초기에 적절한 약제를 살포하여 전염원의 밀도를 낮추는 것이 무엇보다 중요하다. This study was aimed to understand conidial disperse of the pepper anthracnose fungus Colletotrichum acutatum, elapse time for the disease development, and inoculum potentials on infected fruits. Most (99.2%)conidia of the fungus disseminated from inoculum source on the rainy day, while only 0.8% conidia dispersed on the sunny day. Among the conidia 93.3% were caught under 60 cm height at 30 cm distance; however,conidia were detected at 120 cm height at the distance. Relatively susceptible pepper fruits to anthracnose showed first visible symptoms at 4 days after infection under a mimic field condition. However, it seemed that over 10 days are required for the disease to develop on moderately resistant pepper fruits under unfavorable conditions. The number of conidia formed on a lesion was positively correlated with the lesion size (R2=0.88). Over 10 millions of conidia were formed at a normal lesion size 1.5 cm in length. In some large coalesced lesions ca. 4cm in length produced over 100 millions of the fungal conidia. Results further confirmed that the rainfall is the key factor for the inoculum disperse of the pepper anthracnose pathogen, Colletotrichum acutatum, and a long distance dissemination is plausible according to rain and wind intensity. Consequently,rain-proof structures are ideal to avoid the disease, and removal of infected fruits and timely chemical spray are indispensible to reduce the inoculum potential in the field.

Occurrence of Stem and Fruit Rot of Paprika Caused by Nectria haematococca

지형진,류경열,남기웅,심창기 한국식물병리학회 2005 Plant Pathology Journal Vol.21 No.4

Since 2000 severe rots on aerial and underground parts of paprika (Capsicum annum L.) has occurred in most surveyed glasshouses throughout the country. A total of 56 isolates of a fungus were consistently isolated from various plant parts such as fruit, stem, branch, and root collected from 16 farms in five provinces. Anamorph stage of the fungus was identified as Fusarium solani based on its morphological characteristics. However,the fungus readily produced a sexual structure of perithecia on infected plant tissues and on agar media. Since the fungus formed abundant perithecium by a single isolate, it was considered as a homothallic strain of Nectria haematococca, the teleomorph of F. solani. Irregularly globose perithecia with orange to red color formed sparsely to gregariously on dead tissues of fruits and basal stems at the late infection stage, which is a diagnostic sign for the disease. Perithecia ranged from 125 to 220 μm in diameter varied among isolates. Asci enveloping eight ascospores were cylindrical and measured 60-80×8-12 μm. Ellipsoid to obovate ascospores are two-celled and measured 11-18×4-7 μm. Ascospores were hyaline, slightly constricted at the central septum, and revealed longitudinal striations that is characteristic of the species. This fungus that has never been reported in Korea has previously become a threat to paprika cultivation because of its strong pathogenicity and nationwide distribution.

배역병 발생 생태와 방제 - 수생균의 일종$\cdot$장마기에 급속 증식$\cdot$물따라 전파 - 적용약제 없어 예방이 최선$\cdot$감염목은 한곳에 모아 소각해야

지형진 한국작물보호협회 1998 자연과 농업 Vol.19 No.4

Control of Powdery and Downy Mildews of Cucumber by Using Cooking Oils and Yolk Mixture

지형진,심창기,류경열,박종호,이병무,최두회,류갑희 한국식물병리학회 2009 Plant Pathology Journal Vol.25 No.3

Powdery and downy mildews caused by Sphaerotheca fusca and Pseudoperonospora cubensis are the most common and serious diseases of cucumber worldwide. In spite of the introduction of highly effective systemic fungicides, control of these diseases remains elusive. Hence, this study aimed to develop an alternative method to chemicals in controlling the diseases by using different types of cooking oil. Egg yolk, which contains a natural emulsifier, lecithin, was selected as a surfactant to emulsify the oils. Among the different cooking oils used, soybean, canola (rape seed), safflower, sunflower, olive, and corn oils showed over 95% control values against powdery mildew of cucumber in a greenhouse test. In particular, 0.3% canola oil emulsified with 0.08% yolk (1 yolk and 60 ml canola in 20 l spray) was found to be the most effective. The treatment resulted in 98.9% and 96.3% control efficacies on powdery and downy mildews, respectively, of cucumber in the field. Canola oil exhibited direct and systemic effect, wherein powdery mildew of cucumber was suppressed only on treated leaves but not on non-treated leaves in a plant, while mycelia and conidia of the pathogen were severely distorted or destroyed by the treatment. The prospect of using the canola oil and yolk mixture as a natural fungicide is highly promising because of its effectiveness, availability, low cost, simple preparation, and safety to humans and the environment. The use of the canola oil and yolk mixture is expected to be an effective fungicide for use in organic farming and home gardening.

A Simple Method for Sporangial Formation of the Rice Downy Mildew Pathogen,Sclerophthora macrospora

지형진 한국식물병리학회 2002 Plant Pathology Journal Vol.18 No.2

A simple method for sporangial formation of the rice downy mildew pathogen, Sclerophthora macrospora, on infected leaf tissues was developed to facilitate diagnosis of the disease. Freshly infected young leaves showing whitish to yellowish small spots were selected and cut into small pieces about 2-3 cm in length. About 10-20 pieces were surface sterilized in a 100 ml Duran bottle with 40 ml of 70% ethanol by vigorous shaking for 30 seconds. After washing three times with distilled water, the leaf cuts were submerged in 10 ml of Milliporefiltered paddy water and incubated at 20ºC in the dark. After 8-10 h of incubation, the bottle was vigorously agitated on a voltex mixer. Aliquot amount of the suspension, 0.1-1.0 ml, was spread on a slide glass and examined under a light microscope at 50 or 100x magnification. It was found that light and 1% NaClO strongly inhibit sporangial formation of S. macrospora. Meanwhile, the use of freshly infected young leaves and washing with 70% ethanol stimulated sporangial formation of the fungus on rice leaves.

친환경 유기 농업의 현황과 전망

지형진 동아시아식생활학회 2013 동아시아식생활학회 학술발표대회논문집 Vol.2013 No.4

Phytophthora 속균의 특성 및 분류

지형진 한국식물병리학회 1998 식물병연구 Vol.4 No.1

Podosphaera fusca에 의한 상추 흰가루병의 증상과 피해

지형진,류경열,심창기,신현동 한국식물병리학회 2006 식물병연구 Vol.12 No.3

Leafy lettuce (Lactuca sativa L.) is one of the most important vegetable crops in Korea, cultivated throughout the year in greenhouses. During the autumn of 2005, powdery mildew of lettuce that is a new disease caused by Podosphaera fusca occurred in several plantings grown in plastic houses near Suwon in central Korea. Further survey on commercial fields of the plant in central and southern Korea revealed its widespread occurrence and severe losses. Infections occur on upper part of mature leaves often cause leaf distortions, withering, and reduced vigor and growth. Among 184 greenhouses surveyed 121 were infested by the disease and 52 showed over 10% infection rate. Yields were greatly reduced by the disease reaching only 59% compared to healthy plants. About 60% leaves of infected plant were not marketable and fresh weight of the leaves was 73.6% compared to healthy leaves. Total yield of the greenhouses infested by the disease ranged from 100~140 kg, while it was 260 kg in a non-infested greenhouse at one time harvest. Since the disease represents a threat to safe cultivation of leafy lettuce in Korea, environmentally-friend control strategies should be urgently developed.

Nectria haematococca에 의한 착색단고추 줄기 및 과실썩음병의 약제방제

지형진,심창기,류경열,남기웅 한국식물병리학회 2005 식물병연구 Vol.11 No.2

A previous study reported that the stem and root rot of paprika (Capsicum annum L. var. grossum) caused by Nectria haematococca became a threat to safe cultivation of the plant in the country. However, no strategies for control the disease have been suggested. In this study, fungicides registered for pepper were screened to evaluate their control effects on the disease. Among fungicides tested, prochloraz manganase complex completely suppressed mycelial growth of the pathogen at 10 ppm a.i. tebuconazole, benomyl, and carbendazim· kasugamycin also effectively inhibited mycelial growth of the fungus. However, kresoxim-methyl and trifloxystrobin did not suppress mycelial growth but significantly suppressed conidial germination of the fungus. Azoxystrobin, benomyl, prochloraz, tebuconazol, and carbendazim · kasugamycin were also effective to retard conidial germination. In vivo tests, tebuconazole strongly inhibited the plant growth even at 16,000x (15.6 ppm a.i.), while others did not induce chemical injury at 4,000× or 8,000× when drenched into a rockwool cube. In a greenhouse test, prochloraz manganase complex at 125 ppm a.i. (4,000×) showed highest control value by 89.9%. Other fungicides thiophanate-methylthiram, axozystrobin, trifloxystrobin, and benomyl presented 60-80% control value in the hydroponic cultivation system. However, application time and interval remained to be investigated for identify maximum residue limit. Nectria haematococca에 의한 착색단고추 줄기 및 과실 썩음병은 착색단고추의 안정 생산에 가장 큰 장애요인이 되고 있으나 아직까지 마땅한 방제방법이 없는 실정이다. 본 연구는 착색단고추에 등록된 살균제 중 본 병해 방제에 가장 우수한 농약을 선발하고자 수행되었다. 시험에 사용한 7종의 살균제 중 프로라츠망간은 10 ppm a.i.에서 병원균의 균사생장을 완벽하게 억제하였으며 다음은 터부코나졸, 가벤다가스신, 베노밀 순이었다. 병원균의 포자 발아 억제효과는 크레소심메틸과 트리프록시스트로빈이 가장 높았고 다음은 프로크로라츠, 베노밀, 아족시스트로빈 등이 높았다. 이들을 락울배지에 관주하였을 약해를 발생하지 않는 최소희석농도는 살균제별로 2,000~4,000배 액으로 나타났는데, 터브코나졸은 16,000배액에서도 작물 생장을 강력하게 억제시켜 관주처리는 할 수 없는 것으로 조사되었다. 온실포장시험 결과 프로라츠망간이 병 방제효과가 가장 우수하였으며 방제가는 89.9%였다. 다음은 지오판이 80.1%로 높았고 아족시스트로빈과 트리프록 시스트로빈은 70%, 베노밀과 가벤다·가스신은 60%로 나타났다. 본 연구결과를 농가에서 직접 활용하기 위해서는 국내 및 수출대상국인 일본의 잔류허용기준을 준수할 수 있도록 관주시기와 횟수 등의 연구가 후속되어야 할 것이다