• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.230-237
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• 1995

Airborne and waterborne ascospores and conidia of Botryosphaeria dothidea were collected in apple orchards at Suwon and Chunan in 1992 through 1994. Both waterborne and airborne spores were first detected in mid April to early May. Thereafter, spores were abundant in early June to late August and present until early December. Rainwater collections contained much more conidia than ascospores during the apple growing seasons. Airborne ascospores catches, which were also detected on humid days without measurable rainfall, were much more than airborne conidia catches. High amounts of ascospores were detected in early times of apple growing season, whereas most conidia catches occurred in later times of the season. The number of waterborne conidia and airborne ascospores was positively correlated with mean daily maximum, minimum, and average air temperatures during the trapping periods (p=0.01). However, no significant correlation was found between the number of spores and the total precipitation during the trapping periods.

• The Plant Pathology Journal
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• v.27 no.2
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• pp.138-147
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• 2011

Xylogone ganodermophthora, an ascomycetous fungus, is known to cause yellow rot in the cultivated mushroom Ganoderma lucidum. In this study, we investigated the dissemination of this fungal pathogen in G. lucidum grown in cultivation houses. To determine the role of ascospores produced by X. ganodermophthora in disease development, we constructed a green fluorescent protein-labeled transgenic strain. This X. ganodermophthora strain produced a number of ascomata in the tissues of oak logs on which G. lucidum had been grown and on the mushroom fruit bodies. However, the ascospores released from the ascomata were not able to germinate on water agar or potato dextrose agar. Moreover, less than 0.1% of the ascospores showed green fluorescence, indicating that most ascospores of X. ganodermophthora were not viable. To determine the manner in which X. ganodermophthora disseminates, diseased oak logs were either buried in isolated soil beds as soil-borne inocula or placed around soil beds as air-borne inocula. In addition, culture bottles in which G. lucidum mycelia had been grown were placed on each floor of a five-floor shelf near X. ganodermophthora inocula. One year after cultivation, yellow rot occurred in almost all of the oak logs in the soil beds, including those in beds without soil-borne inocula. In contrast, none of the G. lucidum in the culture bottles was infected, suggesting that dissemination of X. ganodermophthora can occur via the cultivation soil.

• Korean Journal Plant Pathology
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• v.14 no.5
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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.

• Mycobiology
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• v.40 no.3
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• pp.147-150
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• 2012

This paper provides a description of Opegrapha herbarum, Opegrapha viridis and Phaeographis subdividens, all newly identified in the Republic of Korea. The characteristic features of O. herbarum include Varia-type asci, Subelevata-type ascospores, a lack of secondary metabolites and a saxicolous habitat. O. viridis possesses Calcarea-type asci, Vulgata-type ascospores and no chemicals in the thallus. P. subdividens is recognizable by its curved to sinuous lirellae, divergent labia, a brown and uniformly thick proper exciple which is open at its base, 3~4-septate ascospores, and lack of secondary metabolites. All three taxa are now reported to exist on Bogil Island in the Republic of Korea.

• Mycobiology
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• v.48 no.6
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• pp.443-449
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• 2020

Two new species, Thelopsis ullungdoensis and Phylloblastia gyeongsangbukensis are described from Ullung-Do (Island), South Korea. The closest relatives from Europe and Korea are epiphytic Thelopsis flaveola which differs by their immersed or semi-immersed yellow ascomata, ascospores without halo and their habitat of smooth bark (mainly Fagus) in humid and cold climates. Thelopsis gangwondoensis differs by its bigger semi-immersed ascomata (600-700 ㎛ in diam.), oblong halonate ascospores (8-12 × 6-8 ㎛) and its habitat of smooth bark of deciduous trees. P. gyeongsangbukensis differs from its relatives within the genus in having 5-septate ascospores (22-26 × 6-8 ㎛), semi-immersed, subglobose ascomata with a flattened top (250-400 ㎛) and a thin, matt, uneven gray-brown to gray-green continuous thallus without isidia.

• Mycobiology
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• v.28 no.1
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• pp.5-10
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• 2000

The genus Hypoxylon is a member of the Xylariaceae which has brown to dark brown and pha- seoliform single cell ascospores with a conspicuous full germ slit. The isolates of Hypoxylon collected from England, Hong Kong and Korea are compared with similar taxa and described. These isolations under Hypoxylon section are detailed and illustrated, using light microscopy and scanning electron microscopy. Hypoxylon howeianum and H. rubiginosum are described and compared with former collection from Korea. A key to the species is also included.

• Research in Plant Disease
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• v.7 no.1
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• pp.16-19
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• 2001

The cultural caracteristics of Monosporascus cannonballus causing root rot of Cucurbitaceae plants were examined in vitro, and population density of the fungal ascospores were measured and compared aoming diferent host species and soil depths. Potato-dextrose agar(PDA) was the most appropriate medium for the mycelial growth and perithecial formation among the 5 media tested. Corn-meal agar(CMA), oat-meal agar (OMA) and V-8 juice agar were moderate media for the mycelial growth and perithecial formation, whereas water agar(WA) was poor medium. Perithecia were not formed on WA. Optimum temperature for the formation of perithecia was about 25 to 30$^{\circ}C$. distribution of ascospores in the infested fields was variable amount the curcubitaceae plants and within the same plant species, ranging from 1.7 to 14.6 ascospores in 20 g of soil, but no ascospore was detected in the uninfested field soils. Ascospores were distributed more at 20cm of soil depth than at 10cm or 30cm of soil depth.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.38-41
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• 1987

This investigation was to measure heat resistance (D and Z values) of ascospores of Saccharomyces cerevisiae Py9 and Saccharomyces chevalieri Pw7 isolated from swollen commercially canned peaches. Decimal reduction times (D values) of S. cerevisiae Py9 ascospores were 6.5 min at $58^{\circ}C$, 2.5 min at $60^{\circ}C$ and 1.25 min at $62^{\circ}C$. Those of S chevalieri Pw7 ascospores were 35.0 min at $58^{\circ}C$ 3.5min at $60^{\circ}C$ and 1.5 min at $62^{\circ}C$ Zvalues of S. cerevisiae and S. chevalienri ascospores were $5.5^{\circ}C$ and $3.4^{\circ}C$, respectively.

• The Plant Pathology Journal
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• v.17 no.4
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• pp.216-221
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• 2001

Dieback of pine branches or twigs with brown needles occurs most commonly on Pinus species after severe winter in Korea. In this study, Cenangium ferruginosum was isolated from infected stems, branches, and twigs of Pinus koraiensis (C1), P. densiflora (C2), and P. thunbergii (C3). Morphological and cultural characteristics of the isolates were than compared. There were no significant differences in the morphological characteristics of conidia and ascospores produced by the three isolates. However, cultural differences were observed among the isolates. Optimum temperatures for mycelial growth of C1, C2, and C3 were 15, 20, and $20^{\circ}$, respectively. C1 produced a few conidia and no ascospores, while C2 and C3 produced abundant ascospores and conidia. While optimum temperatures for mycelial growth ranged from 15 to $20^{\circ}$, mycelial growth was also relatively good at lower temperatures of 5-$10^{\circ}$. Conidiomata and conidia were produced on MSA (malt extract soya peptone agar) after 25-30 days of incubation in the dark at $15^{\circ}$. Apothecia were produced by altering culture condition from 15 to $20^{\circ}$, and incubating for 35-60 more days. Optimum temperature for ascospore and conidium germination was $20^{\circ}$. RAPD analysis revealed that there was high similarity of 0.78 between C2 and C3, and low similarity of 0.31 between C2 or C3 and C1.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.344-347
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• 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.