• Weed & Turfgrass Science
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• 제2권3호
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• pp.306-311
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• 2013

Pythium aphanidermatum에 의한 잎마름병(pythium blights)이 chewing fescue "Jamestowm II" 품종에서 2011년 6월 상순에 대구대학교 시험포장에서 발생하였다. 잔디에 발병증상은 잎 끝으로부터 잎마름 증상과 뿌리 썩음증상이 나타나고, 잎색은 진한갈색,회 갈색으로 나타났다. 병원균은 병든 잎과 지제부에서 분리를 하였으며, 동정을 위하여 PDA에서 배양하였다. 균사에는 잎 같은 포자가 복잡한 구조로 부풀어져 있고, 균사로부터 구별되지 않은 실같은 포자낭이 있다. 리보소옴 DNA의 염기서열을 분석한 결과, 유전자은행 DB에 P. aphanidermatum 균주 와의 100% 상동성을 나타낸다는 것을 확인하였다. 병원성은 chewing fescue, creeping bentgrass 및 Kentucky bluegrass에서 코흐의 원칙에 따라 확인하였다. 이것은 chewing fescue 종에서 P. aphanidermatum 에 의한 잎마름병을 국내에서 처음보고 한다.

• 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.

• 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).

• 환경생물
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• 제38권3호
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• pp.416-423
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• 2020

The genus Petroderma never been reported from the coast of Korea. In this study, our collection from Chaeseokang is matched with P. maculiforme morphologically. Petroderma maculiforme is characterized by having small irregular light to dark brown crusts, a basal layer of irregularly shaped cells giving rise to erect parallel filaments which easily separate with pressure, single chromatophore per cell, small spherical to cylindrical unilocular sporangia in a terminal position, and plurilocular sporangia narrower than erect filaments or wider and shorter than erect filaments in a terminal position. In addition, Hineksia sordida was also collected from Korea. It is mostly epiphytic and characterized by uniseriate filamentous thalli forming loose tangled masses, sparse and spiral branching, some long lateral branches, rhizoids occurring throughout the plant, plurilocular and unilocular sporangia scattered on separate plants. Our molecular analyses based on the rbcL gene reveal that our samples of P. maculiforme and H. sordida are nested within the clades of Petroderma and Hincksia, respectively. Therefore P. maculiforme and H. sordida are reported as new records from Korea based on morphological and molecular analyses.

• 환경생물
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• 제36권3호
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• pp.329-335
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• 2018

Acinetospora asiatica and Botrytella reinboldii are reported as two new records from S. Korea based on morphological studies and molecular analyses. A. asiatica is mainly characterized by the presence of sparsely branched uniseriate filaments with diffused meristematic zones, the formation of crampons at right angles, and the formation of plurilocular sporangia on both prostrate and erect filaments. B. reinboldii is characterized by the presence of irregularly alternating branched uniseriate filaments attached by rhizoids, and single or clustered plurilocular sporangia with a single opening. Molecular analyses of rbcL gene revealed that A. asiatica and B. reinboldii are placed within each clade of Acinetospora and Botrytella, respectively.

• ALGAE
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• 제18권4호
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• pp.333-339
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• 2003

To establish a cultivation method of Petalonia fascia, seeds and seedlings cultures and growth tests were performed at the Daeri aquafarm in Haeui, Shinan, Jeollanamdo, Korea. Gametes were easily released from the mature plurilocular sporangia. They developed to crustose discoidal stolons and grew to filamentous and discoidal stolons. The indoor seeding was performed by using the 100-150 ${\mu}m$long fragments of stolons on Porphyra nets and the erect thalli developed from the cuttings when the seawater temperatures were 10-15$^{\circ}C$. In the experimental cultivation in the sea, 1-2mm long plantlets were found after 15 days of cultivation; after two months thalli grew to their maximal size of 215-355 mm long blades; after three months the length of thalli began to decrease due to distal disintegration and the plant color changed to yellow and epiphytic diatoms were attached on the thalli, which deteriorated the quality of products. The cultivation of P. fascia by the regeneration of filamentous-discoidal complexes was carried out successfully for the first time in Korea.

• ALGAE
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• 제35권1호
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• pp.79-89
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• 2020

Pythium species are ubiquitous organisms known to be pathogens to terrestrial plants and marine algae. While several Pythium species (hereafter, Pythium) are described as pathogens to marine red algae, little is known about the pathogenicity of Pythium on marine green algae. A strain of a Pythium was isolated from a taxonomically unresolved filamentous Ulva collected in an intertidal area of Oslo fjord. Its pathogenicity to a euryhaline Ulva intestinalis collected in the same area was subsequently tested under salinities of 0, 15, and 30 parts per thousand (ppt). The Pythium isolate readily infected U. intestinalis and decimated the filaments at 0 ppt. Mycelium survived on U. intestinalis filaments for at least 2 weeks at 15 and 30 ppt, but the infection did not progress. Sporulation was not observed in the infected algal filaments at any salinity. Conversely, Pythium sporulated on infected grass pieces at 0, 15, and 30 ppt. High salinity retarded sporulation, but did not prevent it. Our Pythium isolate produced filamentous non-inflated sporangia. The sexual stage was never observed and phylogenetic analysis using internal transcribed spacer suggest this isolate belongs to the clade B2. We conclude that the Pythium found in the Oslo fjord was a pathogen of U. intestinalis under low salinity.

• Journal of Plant Biology
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• 제36권2호
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• pp.177-182
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• 1993

The root nodules of Elaeagnus umbellata were coralloid-shape due to repeated dichotomous branching of nodule meristem. The filamentous endophyte with vesicle cluster ranging from 30 ${\mu}{\textrm}{m}$ to 60 ${\mu}{\textrm}{m}$ in diameter was present only in the cortical cells. The isolated endophytes in vitro culture showed typical Frankia morphology, consisting of highly branched hyphae ranging from 0.8 ${\mu}{\textrm}{m}$ to 1.0 ${\mu}{\textrm}{m}$ in diameter, terminal and intrahyphal sporangia varing in shape and size up to 60 ${\mu}{\textrm}{m}$ in length and laminated vesicles. Its infectivity and effectivity were confirmed by induction of nitrogen-fixing root nodules on the inoculated seedlings of two Elaeagnus species. Consequently, the isolate was confirmed as a true symbiont of Elaeagnus umbellata root nodule and named Frankia EuIK1.

• Mycobiology
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• 제47권3호
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• pp.273-279
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• 2019

A new species, Pythium subutonaiense, isolated from aquatic environments (lake) in China is being described based on morphological characters and molecular evidence. The isolates grew at temperatures between $5^{\circ}C$ and $38^{\circ}C$, and the optimum temperature was $30^{\circ}C$, with a radial growth rate of 17.6 mm at $25^{\circ}C$ per day. It is homothallic and characterized by globose to sub-globose shaped and mostly terminal or sometimes catenulate hyphal swellings, filamentous non-inflated sporangia, and smooth oogonia with hypogynous and monoclinous antheridia that contained one plerotic oospore. In phylogenetic analysis, inferred based on the internal transcribed spacer region of the ribosomal RNA gene and mitochondrial cytochrome c oxidase subunit 1 gene, the new species formed a distinct lineage in Pythium clade B. Differences between the new species and phylogenetically related and morphologically similar species are discussed.

• 수산해양교육연구
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• 제29권1호
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• pp.234-241
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• 2017

Morphological and molecular information about two microfilamentous endophytic algae of the Grateloupia lanceolata or Bryopsis sp. from Korea is given. Of two endophytes, Phaeophila dendroides is endophytic in Grateloupia lanceolata. It is green in color and composed of uniseriate branched filaments with long setae. Each cell had several pyrenoids. Undulate or twisted Phaeophila-type hair developed from vegetative cells. Dilabifilum arthropyreniae is endophytic in Bryopsis sp. The frond of this species consists of frequently irregular, branching uniseriate filaments. Each cell had a single pyrenoid without hairs. Sporangia were not observed. The ends of the filaments were curved. In the phylogenetic tree, based on tufA and ITS sequences, these two species are nested in the same clade as Phaeophila dendroides and Dilabifilum arthropyreniae, respectively. In this study, these two species are newly recorded in the Korean marine algal flora, based on the morphological and molecular data.