• 한국식물병리학회지
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• 제14권5호
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• pp.393-396
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• 1998

The characteristic Ramularia type conidia of Mycosphaerella nawae were formed on naturally infected leaves. Artificial inoculation with the conidia induced typical symptom on leaves, which was not distinguishable from those of ascospore infection, which has been considered as a primary inoculum source in nature. Also the morphology of the conidia produced on PDA was not different from those formed on artificially inoculated leaves or on naturally infected leaves at later stage of symptom development. Accordingly, we report the role of the conidia as a secondary inoculum of the circular leaf spot pathogen of persimmon for the first time.

• 식물병연구
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• 제8권4호
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• pp.228-233
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• 2002

딸기육묘시 발생하는 탄저병의 1차 전염원을 밝히기 위해 본 시험을 수행한 결과, 육묘포의 토양과 주변 잡초중에는 탄저병균이 검출되지 않았으나 외관상 건전한 딸기의 모주를 습실처리하였을 경우에는 탄저병균이 검출되었다. 딸기묘에 탄저병균의 포자현탁액을 분무접종하였을때 발병은 되지 않았지만 습실처리하였을 경우, 접종 17일 후까지 발병이 되었고, 포자현탁액을 분무접종한 딸기잎을 주사전자현미경으로 관찰하였을 때 접종 7일 후 부착기만 관찰되었다 그러므로 딸기 탄저병은 육묘상에서 딸기 모주를 통해 전염이 되고, 탄저병균의 포자가 모주에 부착되어 있더라도 부적당한 환경조건에 의해 발병되지 않아 육안으로 판별이 불가능하며, 발아가 되었으나 침입이 완전히 이루어지지 않은 경우 부착기로 남아 침입을 시도하는 것으로 생각된다.

• The Plant Pathology Journal
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• 제28권2호
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• pp.172-184
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• 2012

An infection risk model for Phytophthora blight on chili pepper was developed to estimate the first date of disease occurrence in the field. The model consisted of three parts including estimation of zoosporangium formation, soil water content, and amount of active inoculum in soil. Daily weather data on air temperature, relative humidity and rainfall, and the soil texture data of local areas were used to estimate infection risk level that was quantified as the accumulated amount of active inoculum during the prior three days. Based on the analysis on 190 sets of weather and disease data, it was found that the threshold infection risk of 224 could be an appropriate criterion for determining the primary infection date. The 95% confidence interval for the difference between the estimated date of primary infection and the observed date of first disease occurrence was $8{\pm}3$ days. In the model validation tests, the observed dates of first disease occurrence were within the 95% confidence intervals of the estimated dates in the five out of six cases. The sensitivity analyses suggested that the model was more responsive to temperature and soil texture than relative humidity, rainfall, and transplanting date. The infection risk model could be implemented in practice to control Phytophthora blight in chili pepper fields.

• The Plant Pathology Journal
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• 제25권2호
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• pp.128-135
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• 2009

The survival of Colletotrichum acutatum was investigated in soil, infected fruits, and infected fruit debris incorporated into soil at several temperatures with different soil moisture levels. Samples were examined at 2-week intervals for 18 weeks to determine the survival of the pathogen based on the number of colony forming unit (CFU) of C. acutatum recovered on a semi-selective medium. C. acutatum conidia survived in both sterile and non-sterile soil at 4 and $10^{\circ}C$ for 18 weeks. If infected pepper fruits were completely dried, C. acutatum survived for 18 weeks at temperature from 4 to $20^{\circ}C$. Soil temperature and moisture affected the survival of C. acutatum in infected fruit debris incorporated into soil after air-drying. The effect of soil moisture on survival was weaker at low temperatures than at high temperatures. For up to 16 weeks, conidia were recovered from fruit debris in soil that had been kept at 4 to $20^{\circ}C$ and below 6% soil moisture. Conidia were recovered from fields until approximately 6 months after pepper fruits were harvested. Using PCR with species-specific primers and a pathogenicity test, we identified conidia recovered from soil and infected fruit from both the laboratory and field as C. acutatum and as the primary inoculum causing pepper anthracnose.

• The Plant Pathology Journal
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• 제40권3호
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• pp.290-298
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• 2024

K-Maryblyt has been developed for the effective control of secondary fire blight infections on blossoms and the elimination of primary inoculum sources from cankers and newly emerged shoots early in the season for both apple and pear trees. This model facilitates the precise determination of the blossom infection timing and identification of primary inoculum sources, akin to Maryblyt, predicting flower infections and the appearance of symptoms on various plant parts, including cankers, blossoms, and shoots. Nevertheless, K-Maryblyt has undergone significant improvements: Integration of Phenology Models for both apple and pear trees, Adoption of observed or predicted hourly temperatures for Epiphytic Infection Potential (EIP) calculation, incorporation of adjusted equations resulting in reduced mean error with 10.08 degree-hours (DH) for apple and 9.28 DH for pear, introduction of a relative humidity variable for pear EIP calculation, and adaptation of modified degree-day calculation methods for expected symptoms. Since the transition to a model-based control policy in 2022, the system has disseminated 158,440 messages related to blossom control and symptom prediction to farmers and professional managers in its inaugural year. Furthermore, the system has been refined to include control messages that account for the mechanism of action of pesticides distributed to farmers in specific counties, considering flower opening conditions and weather suitability for spraying. Operating as a pivotal module within the Fire Blight Forecasting Information System (FBcastS), K-Maryblyt plays a crucial role in providing essential fire blight information to farmers, professional managers, and policymakers.

• 한국균학회지
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• 제10권2호
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• pp.93-94
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• 1982

Soybean Whetzelinia rot caused by Whetzelinia sclerotiorum was observed in Jinju area. The diseased soybean plants showed withering and sudden collapse under field conditions. Diseased parts exhibited numerous black, irregularly-shaped scleratia embedded in dense white cottonly mycelium on tissue and in the pith of diseased stems. A sclerotium in the moist sand produced several apothecia under laboratary condition. The primary inoculum was supposed to originate from overwintered sclerotia of soil and soybean debris.

• 한국식물병리학회지
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• 제14권5호
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• pp.408-412
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• 1998

In order to illustrate the role of conidia of Mycosphaerella nawae as a secondary inoculum in nature, pseudothecial development on persimmon leaves was investigated microscopically. The fungal ascospores have been believed as the primary or only inoculum source in nature, however, pseudothecia were readily formed on persimmon leaves infected naturally and artificially by conidia. The pseudothecia of M. nawae were found to form in the tissues of infected leaves while the leaves were still hanging on the trees. The size of pseudothecia were approximately 51.0~122.4$\times$51.0~112.2 ${\mu}{\textrm}{m}$ (82.8 $\times$72.5 ${\mu}{\textrm}{m}$in average), the shapes were spherical, ovoid or occidental pear type. The sizes of asci were approximately 30.6~61.2$\times$8.2~10.2 ${\mu}{\textrm}{m}$(46.6$\times$9.4 ${\mu}{\textrm}{m}$ in average) and the shapes were cylinder or banana. The ascospores were mostly spindle type, and the sizes were 10.2~12.2$\times$3.1~4.1 ${\mu}{\textrm}{m}$ (11.4$\times$3.2 ${\mu}{\textrm}{m}$ in average)-like. The pseudothecial formation was initiated before defoliation and morphological characteristics of the pseudothecia, ascus and ascospores on the infected leaves were fully illustrated in this study. Results indicated that conidia of M. nawae induce circular leaf spot of persimmon as much as ascospores, and might play an important role of the disease epidemics in nature.

• 식물병연구
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• 제7권2호
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• pp.107-111
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• 2001

조숙성 콩품종을 이용하는 풋콩 재배에서는 콩 미이라병과 자주무늬병에 의한 꼬투리 품질 저하와 종자콩의 확보문제가 큰 장애가 되고 있다. 콩 미이라병은 병든 식물의 잔사물이 중요한 제1차 전염원이며, 식물체에 감염하여도 살아 있는 조직에서는 균사의 생육이 극히 제한적이고, 잠재감염 상태로 포자형성이 거의 없으므로 이러한 병원균의 특성을 이용하는 재배적 방제의 가능성을 검토하였다. 점적관수는 분무관수에 비하여 무피복 재배에서는 종자감염율을 현저히 감소시켰으나 피복재배에서는 큰차이가 없었다. 피복재배는 콩 미이라병 28.0%, 자주무늬병 29.3%의 방제가를 보였으나 베노밀 방제가에는 미치지 못하였다. 식물체 잔사물 줄기의 78%는 7월초에 병포자가 성숙되어 제1차 전염원으로 작용하며, 당년의 식물체에서 탈락한 노화 떡잎과 염병에서도 7월 중순부터 9월에 걸쳐 충분한 제2차 전염원이 형성되었다 결론적으로, 비닐피복과 점적관수는 콩 수량성에 영향을 미치지 않고 어느 정도의 콩 미이라병과 자주무늬병 방제효과가 있으며, 제2차 전염원을 제거하는 포장위생관리의 병행은 방제효과를 더욱 제고시킬 것으로 보였다.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.424-429
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• 2012

The intention of this research was to investigate the solubilization of primary sewage sludge using lactic acid bacteria cultured in a glucose and yeast extract medium. Glucose as the carbon source and yeast extract as the source of nitrogen were chosen as an economic medium with the potential for the mass production of lactic acid bacteria. The optimal concentrations of the medium were 3% (w/v) glucose and 2% (w/v) yeast extract. In this study, in order to improve field applications for the solubilization of sludge at sewage treatment plants, a powdered form of lactic acid bacteria was produced. The optimal inoculum of the powder for the maximum efficiency of solubilization was 1% (w/v). In that condition, the SCOD value increased from 8600 (mg/L) at the beginning of experiment to 10290 (mg/L) at 96 h, with the highest solubilization rate (20.6% DDCOD) and 11.2% (SCOD). Also, the TVFAs of the lactic acid bacteria inoculation group were produced more than that of the control group. In particular, acetic acid was produced 5 times more in the experimental group than in the control group. In this research, the potential of lactic acid bacteria in the pretreatment of primary sewage sludge as a solubilizer, and as an energy source producer for microbial fuel cells was revealed.

• 한국산림과학회지
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• 제67권1호
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• pp.10-16
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• 1984

Pt균계(菌系)를 증식배양후(增殖培養後) 인공접종(人工接種)한 상수리나무 분묘(盆苗)는 온실내(温室內)에서 자랐으며, 외생균근(外生菌根) Pt가 상수리나무 분묘(盆苗)의 생장(生長)과 발달(發達)에 지대(至大)한 효과(效果)를 나타내었다. 본(本) 실험(實驗)의 3가지 처리중(處理中) Pt 접종분묘(接種盆苗)는 일차측근(一次側根)의 수(數)와 길이, 수고생장(樹高生長), 근부직경(根部直經), 엽면적(葉面積)의 발달(發達)에 현저(顯著)하게 나타나는 유의적인(有意的)인 인자(因子)였다. 그러나 균근(菌根)을 접종(接種)하지 않은 상수리나무 분묘(盆苗)는 외생균근(外生菌根)의 형성(形成)을 볼 수 없었다. 또 Pt 접종분묘(接種盆苗)에 있어서 외생균근(外生菌根)의 접종(接種)은 71.1%였으며, 대부분 외생균근(外生菌根)은 분(盆)의 상부(上部)와 하부(下部)보다는 분(盆)의 중앙부위(中央部位)에서 증가(增加)하는 경향(傾向)을 보였다.