• 한국식물병리학회지
• /
• 제13권4호
• /
• pp.255-256
• /
• 1997

감나무 둥근무늬낙엽병균(Mycosphaerella nawae)의 분생포자를 대량 형성시키는 방법을 조사한 결과 분생포자는 감자한천배지(PDA)를 $25^{\circ}C$ 항온기에 90일간 배양시 $39.0{\times}10^4/ml$의 분생포자가 형성되었다.

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

• 한국식물병리학회지
• /
• 제14권5호
• /
• pp.397-401
• /
• 1998

Asexual spores of Mycosphaerella nawae were profusely produced on PDA after a prolonged incubation at $25^{\circ}C$ for 90 days. When persimmon trees were artificially inoculated by the conidial suspension, typical symptoms of circular leaf spot of persimmon appeared on the leaves two month later. The imperfect stag of the fungus was identified as Ramularia sp. based on following morphological characteristics examined under a light microscope and a scanning electron microscope. Conidia were mostly ellipsoid, but occasionally cylindrical, elongated oval, taro, peanut or gourd shapes and measured as 12.2~32.6$\times$6.1~10.2 ${\mu}{\textrm}{m}$. erect, hyaline, colorless-light brown. Conidia were formed solitarily or in chains on a medium and infected leaves. Conidiophore was erect, hyaline, colorless-light brown. and the size was 20.4~102.0$\times$3.1~10.2 ${\mu}{\textrm}{m}$, respectively. In this paper, we firstly demonstratrated that asexual spores of M. nawae induced persimmon circular leaf spot in nature as well as sexual spores of the fungus. Therefore, it is hypothesized that the imperfect stage of the fungus plays an important role in nature for epidemics as secondary inoculum.

• 식물병과 농업
• /
• 제1권2호
• /
• pp.18-21
• /
• 1995

Mycosphaerella nawae, the causal organism, of spotted leaf casing disease of persimmon, was isolated from infected leaves showing typical symptom. The cultural characteristics of the fungus were compared on artificial media. Among 24 different combinations of culture media and supplements, oatmeal agar+persimmon leaf extract (PLE) and PAD+ PLE+streptomycin showed the highest rate of isolating as 57.1%. The best medium for mycelial growth of the fungus was PDA+persimmon leaf powder (PLP). The colony diameter was reached 47mm for 30 days at 2$0^{\circ}C$. PDA+PLE also supported good mcyelial growth showing 46mm of diameter in same condition. The optimum growth temperature of this fungus in PDA was recognized fairly low. The mycelial growth was higher at 2$0^{\circ}C$ than 15$^{\circ}C$. The variation of pH between pH 4 to pH 8 did not affect to the mycelial growth of the pathogen.

• 한국식물병리학회지
• /
• 제14권5호
• /
• pp.408-412
• /
• 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
• /
• 제11권4호
• /
• pp.344-347
• /
• 1995

Factors affecting on the ascospore release of Mycosphaerella nawae, the causal organism of persimmon leaf casting disease, were investigated. The ascospore release of the pathogen occurred following the precipitation of rain. The ascospore release started from the beginning of raining, reached maximum at 2 hours after the precipitation of rain, and then decreased abruptly. When the inoculum source (a file of infected leaves) was submerged in water to imitate raining conditions, 92.5% of the total ascospores were released within 1 hour after submerging, 5.8% were after 2 hours, 1.4% were after 4 hours, 0.1% were after 8 hours, and none detected after 10 hours. The inoculum source overwintered in the field released ascospores much more and earlier than the inoculum source kept in the greenhouse. The first ascospore release was about 10 days earlier, and the amount of the total liberated spores was 3∼4 times higher in the field inoculum source than the greenhouse nioculum source. The early defoliated leaves (in early October) in the previous year produced ascospores twice more than the late defoliated leaves (in early November) produced.

• Mycobiology
• /
• 제44권4호
• /
• pp.191-201
• /
• 2016

In this study, the phylogeny and morphology of Mycosphaerella nawae (Dothideomycetes, Ascomycota) were examined using Korean and Japanese isolates, to establish the phylogenetic relationship between M. nawae and its allied species. Korean and Japanese isolates of M. nawae were collected from circular leaf spot-diseased leaves and were confirmed based on internal transcribed spacer (ITS) sequence data. Phylogenetic analysis was conducted using multiple genes, including the ITS region, 28S rDNA, ${\beta}-tubulin$, translation elongation $factor-1{\alpha}$, and actin genes. Our results revealed that M. nawae is closely related to members of the genus Phaeophleospora but are distant from the Ramularia spp. In addition, microscopic analysis revealed pseudothecia on the adaxial and abaxial surface of overwintered diseased leaves (ODL) and only on the abaxial surface of diseased leaves. Ascospores are oval to fusiform, one-septate, tapered at both ends, $1.7{\sim}3.1{\times}8.1{\sim}14.1{\mu}m$, and were observed in ODL. Conidia are oval, guttulate, one-septate, $3.5{\sim}4.9{\times}12.8{\sim}19.8{\mu}m$, and barely discernable on 30-day cultures. To our knowledge, this is the first report on the phylogeny of M. nawae, which is closely related to the genus Phaeophleospora, especially P. scytalidii.

• 한국식물병리학회지
• /
• 제13권4호
• /
• pp.215-218
• /
• 1997

감나무 둥근무늬낙엽병 이병엽에서의 이듬해 봄 위자낭락 성숙에 영향을 미치는 환경요인에 대한 검토를 하였다. 월동 후 이병엽에서 위자낭각이 완전히 성숙되는 시기는 대체로 4월 하순이었는데 이때의 평균 기온은 $14^{\circ}C$ 정도였고 충분한 강우가 있을 때였다. 낙엽시기에 따른 성숙 정도는 10월 초에 낙엽된 이병엽이 11월 초 낙엽된 이병엽보다 성숙율은 상당히 높았으나 성숙시기에는 차이가 없었다. 월동장소에 따른 차이는 야외에서 월동된 이병엽은 온실에서 보관되었다가 이듬 봄에 야외에 노출한 것보다 성숙시기가 20일 정도 빨랐고 성숙율도 훨씬 높았다. 그리고 분생포자를 인공접종하여 발병된 이병엽에서도 위자낭각이 다수 형성되었고 이듬해 봄 성숙율도 자낭포자의 자연감염에 의한 병반에서와 큰 차이가 없었다.

• 식물병연구
• /
• 제10권4호
• /
• pp.209-216
• /
• 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.

• 한국응용곤충학회지
• /
• 제53권2호
• /
• pp.157-169
• /
• 2014

단감 병해충의 관리와 원활한 수출 정보를 위하여 2010년부터 2012년까지 3년 동안 전남 순천, 경남 진주, 창원(동읍과 북면), 김해, 그리고 울산 울주지역의 수출과원과 비수출과원과 수확과에서 병해충을 조사하였다. 수출 단감과원에서 확인된 병은 모무늬낙엽병, 탄저병, 둥근무늬낙엽병, 흰가루병, 잿빛곰팡이병이었고, 그 중 둥근무늬낙엽병의 피해가 높은 편이었다. 과일에서는 Colletotrichum gloeosporioides와 Colletotrichum acutatum 탄저병의 피해가 문제였다. 발견된 해충은 5목 20과 32속 33종이었고 점박이응애도 발생하였다. 그 중 애무늬고리장님 노린재와 식나무깍지벌레, 애모무늬잎말이나방이 비교적 넓은 지역에서 발생하고 있었고, 담배거세미나방, 차잎말이나방 등도 발생하고 있었다. 해충에 의한 피해는 매우 낮았다. 검역대상 해충인 복숭아명나방과 감꼭지나방은 거의 발생하지 않았거나 문제가 되지 않았고, 감나무애응애, 온실가루깍지벌레는 전혀 발견되지 않았다. 선과장과 수출과에서는 이들 검역대상 해충인 복숭아명나방, 감꼭지나방, 감나무애응애, 온실가루깍지벌레는 전혀 발견되지 않았고, 깍지벌레와 점박이응애가 낮은 비율로 발견되었다. 병으로는 진주와 김해의 저장고 수확과에서 C. acutatum탄저병 이병과가 1개 과에서만 발견되었다.