• Journal of Plant Biology
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• v.12 no.4
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• pp.1-8
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• 1969

According to the mode of development of antheridia and antheridial mother cells, the antheridium formation of Rhodymeniales is divided into two types. I. Separate Type; Antheridial mother cells are separate one another. Antheridia and the mother cell are surrounded by the common wall. The superficial gelatinous wall covering antheridial sori disappears during the antheridium formation. Spermatia are comparatively large. Halosaccion saccatum, H. firmum, Rhodymenia palmata and Rh. marginicrassa. II. Seriate Type; Antheridial mother cells, originated from the same epidermal cell, are seriate one another with a pit-connection. Antheridia and the mother cell do not have the common wall. The superficial gelatinous wall remains during the antheridium formation. Spermatia are comparatively small. Rhodymenia intricata, Rh. pertusa, Chrysymenia wrightii, Lomentaria hakodatensis, L. catenata, Binghamia californica and Champia parvula.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.92.2-93
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• 2003

Severe soybean-sprout rot was found at the mass productive factory in 2000 and 2001 and it caused 10-20％ loss of the production. Pythium sp. was isolated almost 90％ by potato dextrose agar from rotted root and hypocotylsof the sprouts. And the pathogencity tests using test tubes with 2％ water agar and small containers (30 ${\times}$ 30 ${\times}$ 50 cm, WxLxH) cultivation were shown a similar rot on roots and hypocotyls. The fungal mycelium grew rapidly on the water agar and it prevented the seed germination. Density of the Pythium sp. in the recycled water system at the factory was periodically measured using a selective medium, corn meal agar with Pimaricin 10 mg, Rifampicin 10 mg, Ampicillin 100 mg per 1 liter in order to check the contamination of recycled water. After fitering step using 5 and 1 ml in the recycled system was applied and it was effectively controlled Pythium rot. The daily yield of sprout was stable and the occurrenceof Pythium in the recycled water was much less after filtering. The fungal isolates were identified as Pythium deliense Meurs based on various mycological characteristics on corn meal agar and sucrose-asparagine bentgrass leaf culture medium. P. deliens oogonia were spherical, smooth, 19-23 urn in diameter, and their stalk bending toward antheridia. Antheridia were straw hat-shaped, curred club-shaped, therminal or intercalary, monoclinous, occasionally diclinous, 12∼15 ${\times}$ 8∼11 um, 1(∼2) per oogonium.

• Mycobiology
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• v.34 no.1
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• pp.41-43
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• 2006

Two species of the Laboubeniales based on the Tibetan collections are described. They are new to the mycological flora of Tibet. Laboulbenia polyphaga found on several parts of Amara majuscula was characterized by having the outer appendages not ramified and simple. Peyritschiella protea obtained on the lower abdomen of Philonthus wuesthoffi, had two perithecia and two antheridia produced on the third layer of receptacle.

• Mycobiology
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• v.35 no.1
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• pp.1-5
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• 2007

Three species of the genus Euphoriomyces (Laboulbeniales) were found newly from Korea. E. agathidii (Maire) Tavales was collected from Agathidium sp. (Leiodidae, Coleoptera). The characteristic traits of this species are the distal portion of the primary axis composed of $5{\sim}11$ superposed layers and bearing more or less the elongated appendages. E. cybocephali (Thaxter) Thaxter was collected from Pseudocolenis hilleri Reitter (Leiodidae, Coleoptera). The primary axis of this species composed of $5{\sim}9$ superposed layers is simple, not branched and a single antheridium occurs on the apex of the secondary axis. E. sugiyamae Majewski was collected from Scaphisoma rufum Achard (Scaphidiidae, Coleoptera). This species is very unique in having the antheridia formed as coner cells with lateral necks.

• Mycobiology
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• v.47 no.3
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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.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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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.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.128.2-128
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• 2003

Shoot blight was occurring on shoots of suckers of common lilac (Syringa vulgaris L.) growing in first author's apartment garden in May 2003. A species of Phytophthora was isolated from the lesions. The isolate did not sporulate on agar media but formed sporangia in water and also formed sex organs in single culture. Sporangia were semipapillate, ovoid obpyriform, measured 45.6-52.8 ${\times}$ 33.6-36.0$\mu\textrm{m}$. Sporagia were very variable in shape. Optimum temperature for mycelial growth was 25$^{\circ}C$. Oogonia were spherical and antheridia were paragynous. Optimum temp for mycelial growth was 25$^{\circ}C$. The isolate was identified as Phytopkhora citricola on the basis of the morphological characteristics and cardinal temperature.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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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.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.211-214
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• 2006

In 2004 and 2005, Phytophthora rot on Luffa cylindrica which had not been reported in Korea occurred in the experimental field at Gyeongsangnam-do Agricultural Research and Extension Services. The disease initiated on leaves and fruits of the plant with small watersoaked dark brown spots and progressed rapidly. The causal pathogen isolated from diseased tissues was identified as a Phytophthora sp. because of aseptate mycelia and zoospores released directly from sporangia. The fungus grew well on PDA and 10% V-8 juice agar showing an arachnoid or rosaceous colony pattern. Sporangia formed abundantly in water and were conspicuously papillate, noncaducous, ovoid to globose, and sized $26\sim62\times19\sim38{\mu}m$. The fungus was heterothallic as producing sexual reproduction structures only when mated with only A2 standard mating type strain. Oogonia and oospores were spherical, smooth walled, and measured as $20\sim28{\mu}m\;and\;16\sim24{\mu}m$, respectively. Oospores were aplerotic and antheridia were amphigynous, unicellula and spherical. Chlamydospores were globose and $20\sim38{\mu}m$ in diameter. Optimum temperature for growth was around $28\sim30^{\circ}C$. The fungus caused similar symptoms on artificially inoculated plant and could be re-isolated thereby proving Koch's postulation. Based on the mycological criteria investigated in this study, the causal fungus of Luffa sylindrica rot was identified as Phytophthora nicotianae. This is the first report of Phytophthora rot of Luffa cylindrica caused by P. nicotianae in Korea.

• Mycobiology
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• v.31 no.2
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• pp.86-94
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• 2003

The effect of four sub-lethal concentrations(400, 800, 1,200 and 1,600 ${\mu}g/ml$) of three amino acids such as isoluecine, aspartic acid and phenylalanine on vegetative growth and sexual and asexual reproduction of Achlya racemosa, A. proliferoides and Saprolegnia furcata was investigated. The density of vegetative growth and diameters of vegetative colonies of species of the Oomycetes fungi decreased with rising the concentration of the applied amino acid. Vegetative hyphae of treated fungi almost appeared branched in case of S. furcata, thick in case of A. racemosa and distorted in case of A. proliferoides as compared with control. The different treatments with amino acids depressed both sporangial formation and discharge, which were dependent on the tested species of zoosporic fungi, the amino acid and its dosage. Phenylalanine was the most effective amino acid in inhibiting sporulation and S. furcata was the most sensitive fungal species. Aspartic acid and isoleucine stimulated germination of discharged spores through the formation of germlings. Gemmae formation by the three fungi was reduced at the low concentrations of amino acids and nearly missed at high concentrations. Sex organs(oogonia and antheridia) were affected partly; rudiment oogonia were observed at low concentrations(400 and 800 ${\mu}g/ml$) and disappeared at higher concentrations, whereas antheridial branch formation was stimulated as the fungi were treated with isoleucine and to some extent phenylalanine.