• Mycobiology
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• 제32권1호
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• pp.17-23
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• 2004

Growth of ten isolates of Catenaria anguillulae on linseed oil-cake agar medium was studied at 10, 13, 15, 20, 25, 30, 35, 40, 44 and $46^{\circ}C$. The cardinal temperatures of these isolates were also determined. Observations clearly revealed that the isolates differed in their temperature requirements. Isolate GA was found to grow best at $40^{\circ}C$, whereas VF isolate showed best growth at 35 and $40^{\circ}C$. Isolates PA, KA, CHP, KO, MA and SWP grew best at $35^{\circ}C$. The other isolates(KP and MMT) showed their best growth at $30^{\circ}C$. Based on radial growth, isolates were categorized as fast growing, medium growing and slow growing. Studies on effect of different temperatures on pathogenicity was made using only three isolates: VF, KP and MA against Xiphinema basin. VF isolate caused maximum infection at $40^{\circ}C$, whereas KP and MA isolates caused maximum infection at $30^{\circ}C$. The morphology of sporangia varied with temperature in isolates producing elongate-elliptical or filamentous sporangia. In VF isolate the sporangia were largely iilamentous to elongate elliptical at $30^{\circ}C$. The width of the sporangia increased with increasing and decreasing temperatures. At $44^{\circ}C$ the sporangia of this isolate were mostly broadly elliptical or spherical. This clearly indicates that sporangia vary in morphology with temperature. From the morphometrical studies it was understood that sporangial morphology was more consistent and reliable for grouping of isolates. Based on the morphology of sporangia the isolates of C. anguillulae were characterized in three groups viz., Mamentouslelongate elliptical(VF, KA, GA and SWP), spherical(PA, KP, MA and MMT) and vertically elongate sporangia(CHP and KO).

• The Plant Pathology Journal
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• 제25권2호
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• pp.121-127
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• 2009

Since July 2005, survey of chestnut ink disease was carried out in chestnut stands located at southern parts of Korea. Dead chestnut trees showing inky ooze on necrotic trunks were found in two different locations. In order to isolate and identify the causal fungus, infected tissues and soil samples around dead or dying trees were collected and placed on Phytophthora-selective medium. Rhododendron and chestnut tree leaves were used as a bait to isolate the fungus from soil samples by attracting zoospores in soil suspensions. On V-8 culture medium, the isolates produced homothallic oogonia with protuberances ($34.0-46.2{\times}21.9-26.7{\mu}m$) abundantly, but did not produced sporangia. Mass production of sporangia was possible by immersing agar plugs with actively growing mycelium in the creek water at $18^{\circ}C$ for 3 days. Sporangia were papillate, and ovoid to obpyriform ($17.0-38.9{\times}14.6-29.2{\mu}m$) in shape. Comparison of the ITS sequences revealed that the isolates had 100% identity to the P. katsurae isolates from Japan and New Zealand and 99.6% identity to other P. katsurae isolates. All of the examined isolates from Korea were completely identical to each other in ITS sequence. Numerous sporangia were formed in filtered as well as unfiltered creek water, but no sporangia formed in sterilized distilled water. Light induced sporangia formation, but has no influence on oospore formation. Amendments of ${\beta}$-sitosterol in culture media have no significant effect on mycelial growth but significantly stimulate oospore and sporangia formation.

• Journal of Plant Biology
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• 제19권3호
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• pp.92-94
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• 1976

Elachista tenuis Yamada, epiphytic on Sargassum confusum, is reported for the first time in Korea. It forms hemispherical tufts by pseudoparenchymatous medulla and assimilatory filaments. The cells ofassimilatory filament are not constricted at septa, and nearly equal in breadth from base to apex. Plurilocular sporangia are rather abundant, while unilocular sporangia rare.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.128.3-129
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• 2003

A leaf blight disease caused by a species of Phytophthora has been observed on castor bean plants growing near dwelling houses in Manchon-dong, Daegu since 1993. The first isolate that we have kept was producing papillate, ovoid-obpyriform to obpyriform sporangia with on a simple sympodial sporangiophore from diseased tissue placed on water agar plates. The pure isolate, however, did not sporulate on agar media, and rarely even in water, but produced mycelial swellings and chlamydospores in water. Sporangia measured 26.1-77.4 ${\times}$ 23.2-44.0$\mu\textrm{m}$. Chlamydospores were either terminal or intercalary, and measured 24-29.4$\mu\textrm{m}$ in diameter. Sex organs were not formed in a single culture. In 2003, another pure isolate was isolated from castor bean plants with similar symptoms at the same place. The second isolate was distinct from the first one in that the second isolate was readily and abundantly sporulating on V8 juice agar plates. Sporangia of the second isolate were papillate, ovoid and caduceus with a pedicel. Sporangia measured 19.5-48.8 x 17.6-34.3$\mu\textrm{m}$ with 3.7$\mu\textrm{m}$ high papilla and 4.1$\mu\textrm{m}$ long pedicel. No sex organs were formed in a single isolate culture. Both isolates were pathogenic on castor bean plants. Results of the efforts to identify the two species of Phytophthora will be discussed.

• 한국식물병리학회지
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• 제14권5호
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• pp.445-451
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• 1998

A severe Phytophthora rot of strawberry caused by a species of Phytophthora has been widely occurred at major cultivation areas of Kimhae on August in 1997. Incidence of the disease was obtained in the range of 69.2~83.6% in surveyed 4 fields and showed an average of 75.2%. A species of Phytophthora was mostly isolated from the crown of infected strawberry plants and all the isolates were identified as P. nicotianae var. nicotianae (=P. parasitica). The fungus showed strong pathogenicity on strawberry by inoculation test. As a result of the leaf inoculation using mycelial disks of the fungus, both leaves and petioles were darkly browned, and were finally blighted. As a result of the root inoculation of zoospore suspension, both roots and crowns were rotten with dark brown. Although the fungus produced sporangia either on V-8 juice agar medium or liquid medium, the sporangia observed on the liquid medium appeared to be broadly turbinate and noncaducous. Moreover the fungus cultured on the liquid medium often produced sporangia having two papilla. The number of zoospores in sporangia was found to be ranged from 3 or 4 to as many as 20 or 25. In addition, the released zoospore from the sporangium became the cystospore during the prolonged culture of the fungus. The sporangia were measured as av. 49$\times$35 ${\mu}{\textrm}{m}$ with l/b ratio of 1.43. All isolates from crowns were heterothallic and A1 mating type since oospores were abundantly formed on clarified V-8 juice agar by dual culture with P. capsici A2 mating type. Aplerotic oospores were sized 24-26 ${\mu}{\textrm}{m}$. Antheridia were always amphigynous and recoreded an average of 12$\times$10 ${\mu}{\textrm}{m}$. Hyphal swlling were easily observed, and terminal or intercalary chlamydospores were abundantly formed on V-8 juice agar as well as in C/Z solution and sized av. 28.2 ${\mu}{\textrm}{m}$. This is the first report of Phytophthora rot of strawberry in Korea.

• 환경생물
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• 제37권3호
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• pp.278-284
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• 2019

Feldmannia chitonicola is reported as a new record from Korea based on morphological studies in laboratory-cultured materials and molecular analyses. F. chitonicola is mainly characterized by a small size (1-2 mm), erect filaments mostly unbranched, plurilocular sporangia produced on both prostrate and laterally on the basal part of erect filaments, and 2 types (lanceolate and ovate) of sporangia. In our cultures, sporangia production was slower at 10℃ than in 16℃ and 20℃. Our molecular analyses of rbcL and cox1 genes supported its independence from other congeners reported for Korea. This is the first report of F. chitonicola for western Pacific.

• 환경생물
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• 제37권3호
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• pp.285-292
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• 2019

Acinetospora filamentosa and Microspongium stilophorae are reported as new records from South Korea based on morphological and molecular analyses. A. filamentosa is mainly characterized by having the sparsely branched erect filaments, the scattered meristematic zones, forming crampons, plurilocular sporangia on both prostrate filaments and lower part of erect filaments, and spherical to oval unilocular sporangia formed either sessile or with a pedicel. M. stilophorae is an epiphytic thalli mostly on Stilophora sp. It is characterized by prostrate filaments with irregular cells, short erect filaments with short ramuli, phaeophycean hairs, uniseriate plurilocular sporangia on the terminal part of erect filament. Our molecular analyses of rbcL and cox1 genes reveals that A. filamentosa and M. stilophorae are nested within the clades of Acinetospora and Microspongium, respectively.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.128.1-128
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• 2003

A leaf blight disease was found on Fatsia japonica plants growing in the first author's apartment garden in May, 2003. Major symptoms were leaf blight and petiole rot. A species of Phytophthora was isolated from the lesions. The isolate readily produced sporangia and sex organs on V8 juice agar plates. Sporangia were papillate, ovoid to subspherical and caducous with a pedicel. Sporangia were 33.6-38.4 ${\times}$ 33.6$\mu\textrm{m}$ with 1/b ratio approximately 1.14, papillae 4-5$\mu\textrm{m}$ high, pedicels also 4-5$\mu\textrm{m}$ long. Oogonia were spherical, 28.8$\mu\textrm{m}$ in diameter. Antheridia were globose, 14.4$\mu\textrm{m}$ in diameter and mating with oogonia paragynously. Mycelia grew best at 30$^{\circ}C$ and did not grow at 35$^{\circ}C$ or above, and at 5$^{\circ}C$. The morphological characteristics conformed to P. cactorum (Leb. And Cohn) Schroeter.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.127.3-128
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• 2003

A leaf blight disease was found on peony plants growing in the first author's apartment garden in May, 2003. A species of Phytophthora was isolated from the lesions. The isolate readily produced sporangia and sex organs on V8 juice agar plates. Sporangia were papillate, ovoid to subspherical and caduceus with a pedicel. Sporangia were 33.6-38.4 ${\times}$ 33.6$\mu\textrm{m}$ with 1/b ratio approximately 1.14, papillae 4-5$\mu\textrm{m}$ high, pedicels also 4-5$\mu\textrm{m}$ long. Oogonia were spherical, 28.8$\mu\textrm{m}$ in diameter. Antheridia were globose, 14.4$\mu\textrm{m}$ in diameter and mating with oogonia paragynously. Mycelia grew best at 30$^{\circ}C$ and did not grow at 35$^{\circ}C$ or above, and at 5$^{\circ}C$. The morphological characteristics conformed to P. cactorum.

• Journal of Plant Biology
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• 제30권4호
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• pp.311-321
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• 1987

Morphotaxonomic accounts are given to three taxa of Sphacelaria, Phaeophyta from Cheju Island; S. tribuloides Meneghinim, S. subfusca Setchell et Gardner, and S. yamdae Segawa. S. tribuloides has tribuliform propagules and produces plurilocular sporangia. S. subfusca has bifurcate or trifurcate propagules, and reproductive structures except propagules are not found. S. yamadae has twice bifurcate propagules and produces unilocular sporangia. Several taxa morphologically related to these three species are menioned. S. tribuloides and S. subfusca are introduced for the first time to Korean flora.