• 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.

• 한국식물병리학회지
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• 제12권4호
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• pp.395-401
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• 1996

국내의 고추, 사과, 포도, 스타티스(statice)에서 분리한 Glomerella cingulata 균주들의 병원성과 체세포화 합성군(vegetative compatibility group : VCG)과의 관계를 조사하였다. 사과, 포도, 스타티스에서 분리된 균주들은 전기주에 모드 병원성을 나타내었으나 고추에는 병원성이 없었다. 한편, 고추에서 분리된 균주들은 무상처접종시 병원성을 나타내지 못하였다. Nitrate nonutilizing(nit) mutant는 1.5%의 KClO\ulcorner을 첨가한 최소배지에서 선발하였다. nit mutnat들은 nit1, nit2, nit3, nitM의 4가지 표현형 중 하나에 속하였다. VCG는 표현형이 다른 nit mutan간의 대치배양을 통해 결정하였는데 사과, 포도, 스타티스에서 분리한 균주들간에는 같은 VCG를 나타낸 반면 고추에서 분리된 균주들은 다른 VCG로 나타났다. 따라서 G. cingulata 균주들의 체세포화합성은 병원성과 밀접하게 관련되어 있음을 알수 있었다. 또한 동일한 VCG에 속하며 기주가 다른 균주들의 대치배양시 heterokaryon을 형성했으나 자낭을 형성하지는 않았다.

• 한국응용곤충학회지
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• 제12권3호
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• pp.121-124
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• 1973

새로운 수도품종통일에 발생하는 갈색엽고병 유사증상을 발견하여 그 병반에서 병원균을 분리하여 그 형태를 조사하였으며 분생포자, 병반상에 형성하는 자남, 자남포자의 기재를 타연구자를의 문헌과 비교한 결과, 이는 일본에서도 보고된 바 있는 갈색엽고병임이 확인되었으며 병원균이 Fusarium nivale로 동정되었다. 또한 포장조건하에서는 본병은 다질소구에서 그 발생이 현저히 많았음을 관찰하였고, 본균의 생육적온은 $24^{\circ}C$였다.

• 식물병연구
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• 제10권4호
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• pp.209-216
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• 2004

The circular leaf spot of persimmon is occurred almost every place where persimmon is cultivated, especially the disease outbreak severely in southern part of Korea. The disease reveals unusually long incubation period after pathogen invade into leaf tissue and no practical control measure is available once the symptom has appeared. Most of the farmers just follow the suggested spray schedules calculated on the basis of weather condition of ordinary years. Therefore the damages due to circular leaf spot greatly differ year after year. In this article, we tried to describe and summarized the investigation on the circular leaf spot pathogen, Mycosphaerella nawae, related to disease outbreak such as overwintering of pathogen, inoculum formation and spread, incubation period after infection, and secondary inoculum. With the summary of these results, we suggest the disease cycle of circular leaf spot of persimmon. The pathogen overwinters in diseased leaves as mycelial form or pseudoperithecial premodium. The pseudoperitheria become matured in spring as the temperature raise and forms asci and ascospores. The maturation of pseudoperithecia are closely related to the temperatures during March and early April. The ascospores completely mature in early May and the ascospores released when the pseudoperithecia absorbed enough moisture after rainfall. The release of ascospores are diverse greatly with the variation of maturity of pseudoperithecia. Generally the spore start to release from middle of May to early of July. Duration of ascospore release is depend on the weather condition of particular year, especially amount and number of precipitation. The ascospores produced from pseudoperithecia is known to the only inoculum for circular leaf spot disease. But according to the results obtained from our investigations, the conidia formed on the lesions which incited by natural infection. This conidia are infectious to persimmon leaves and formed identical symptom as natural infection. The time of producing secondary inoculum of circular leaf spot of persimmon is considered too late to develop new disease. Generally the importance of secondary inoculum is low but the conidia produced in early September are competent to develop new disease and new infection also significantly affect to harvest of persimmon. The importance of circular leaf spot disease is recognized well to farmers. The approaches to control of the disease should be initiated on the basis of the knowledges of inoculum dynamics and ecology of disease development. The forecasting system for circular leaf spot is need to be developed.

• 한국균학회지
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• 제26권2호통권85호
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• pp.287-292
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• 1998

율무 잎마름병을 일으키는 Bipolaris coicis의 완전세대를 배양기내에서 형성하도록 유도하였다. 국내 17개 지역에서 1994년부터 1996년까지 89개의 균주를 수집하였다. 이들을 $25^{\circ}C$에서 볏짚을 위에 올려놓은 Sach's nutrient agar 배지에서 대치배양하였다. 위자낭각은 특정 친화적인 균주의 조합일 때만 형성되었다. 위자낭각은 대체로 배양 2주 후에 볏짚 위에 형성되었으나, 일부 위자낭각에서만 자낭과 자낭포자가 관찰되었다. 위자낭각은 흑색이며 구형이었고, 돌출한 ostiolar beak을 가지고 있었다. 그 내부는 무색이고, 사상형민 위측사로 채워져 있었다. 자낭은 원통형내지 곤봉형이었고, 직선형이거나 약간 굽은 것도 있었다. 자낭벽은 이중격막으로 둘러싸여 있었고 짧은 stipe가 있었다. 자낭포자는 사상형이고 무색이었으며, 자낭의 장축과 평행하거나 약간 나선형으로 굽어 있었다. 자낭포자의 크기는 $146-166.4{\times}2.6-3.8\;{\mu}m$이었다. 이러한 형태적 특징에 기초하여 이 곰팡이의 완전세대는 Cochliobolus nisikadoi (Tsuda, Ueyama & Nishihara Alcorn)으로 동정되었다.