• Journal of Plant Biology
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• v.30 no.4
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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.

• Korean Journal of Plant Tissue Culture
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• v.28 no.3
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• pp.117-121
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• 2001

Microstructure of abaxial leaf surface and carbohydrate content of propagules grown in different culture conditions such as heterotrophic, mixotrophic and autotrophic carbon source were investigated. In the leaves of propagules which were grown in the green house, autotrophic and mixotrophic conditions, wax layer was observed, but in the leaves of the heterotrophic propagules, it was not observed. Size and number of stomata of the leaves in the heterotrophic condition was larger and more numerous than that of autotrophic propagules. Especially, stomata of the leaves in the autotrophic condition was similar to the leaves of plant grown in green house. Carbohydrate content was higher in photoautotrophic condition than that in mixotrophic and heterotrophic culture. Also, Free sugar content showed higher in photoautotrophic propagules than that in mixotrophic and heterotrophic culture. In all the culture conditions, content of glucose were higher than that of other free sugars.

• ALGAE
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• v.20 no.1
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• pp.1-13
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• 2005

The taxonomic status of three closely related species of the genus Sphacelaria, S. rigidula Kützing, S. fusca (Hudson) C.F Gray and S. didichotoma Saunders was reassessed on the basis of morphological observations from herbarium specimens and phylogenetic analysis of RUBISCO spacer sequences. Sphacelaria rigidula was characterized by having only 2-armed propagules and somewhat slender filaments. Culture experiments revealed that its propagules commonly formed secondary arms, even though they were rarely produced in the field. It is concluded that S. divaricata Montagne characterized by dichotomously branched arms in propagules shoud be synonymized with S. rigidula, based on propagule morphology and measurements. Sphacelaria fusca clearly be separated from S. rigidula by having 2-4 armed propagules. These morphological differences were highly supported by the differences in the RUBISCO spacer sequences. S. didichotoma resembles S. rigidula in having propagules with two dichotomously branched arms. However, it commonly produces the secondary arms in the field. Additionally, this species has shorter primary arms than S. rigidula. Phylogenetic analyses supported the distinction of S. didichotoma from S. rigidula. The northwestern Pacific plants, previously recorded as S. divaricata, were recognized as S. didichotoma.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.157-165
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• 1984

Seasonal and spatial variations in propagule numbers of Trichoderma species were investigated every other month for one year in deciduous and coniferous forest soils and evaluated the relationships of Trichoderma spp. populations to soil environmental factors. The total population of Trichoderma spp. increased until summer and then declined until winter. The yearly mean frequency of Trichoderma spp. exceeded 1.4% of total fungal propagules in two sites. Decreases of absolute an relative propagule numbers of Trichoderma spp. with increasing soil depth were found and variation in Trichoderma spp. propagules caused by differences in soil depth ($0{\sim}50cm$) was greater than that caused by differences in sampling time. The most common species occurring in two sites was T. viride, followed by T. polysporum, T. koningii, and T. hamatum. Individual species of Trichoderma showed diferent abundance trend in accordance with sampling time. T. viride was dorminant from spring to autumn, while T. polysporum dominated over the other speicies in winter. Variations in propagule number of Trichoderma sppp. were principally mediated by the actions of biotic environmental factors rather than by the direct effects of abiotic factors. In multiple-regression analyses, 48% of the total vaiation in Trichoderma spp. propagules in deciduous site could be accounted for by total fungal propagules and soil CMCase actvity. In coniferous site, 65% of total variation could be accounted for by total fungal and bacterial propagules, moisture content and organic carbon content.

• The Korean Journal of Mycology
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• v.14 no.2
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• pp.109-119
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• 1986

The correlations between environmental influences on microorganisms in soil and its effects on disease development in ginseng field were studied to obtain some useful data for increasing ginseng production and effective preventive measures against the root rot caused by soil-borne pathogens. The diseased replanted ginseng fields were selected as the diseased field and the healthy plot in first planted field selected as control in three major Korean ginseng producing areas such as Kumsan, Goesan and Poonggi. The physicochemical characteristics of the soil were analyzed and microorganisms susceptible for root rot of ginseng, such as Fusarium spp. and general fungi were investigated for their population density in various soil conditions. Correlations between soil microbial populations and environmental factors were investigated. The numbers of Fusarium spp. propagules were abundant in fall in both soil conditions. The numbers of Fusarium spp. were 1.9 to 2.6 times higher in replanted field than first planted field except Goesan area. Relative ratio of Fusarium spp. to total fungi propagules in replanted field was 1.6 times higher in replanted field than first planted field indicating higher numbers of Fusarium spp. distributed in replanted field of soil. The numbers of propagules of total fungi were increased in June and July and there was no sensitive variation according to the temperature. There was no significant difference in vertical distributions of total fungi according to soil depth, while the total fungi were abundant in the surface layer and $10{\sim}15\;cm$ layer. The contents of organic matter and phosphate in healthy field were somewhat high, and phosphate/organic matter ratio and Mg contents were high in diseased field. All of the soils showed a weak acidic pH of 4.5 to 5.7. Soil moisture contents were increased during winter season, but did not show any significant changes during the growing periods, showing 24.6% in healthy field and 19.5% in diseased field respectively. Soil temperature was the highest in July and August and the lowest in January and February.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.91-95
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• 2001

Propagules grown at different in vitro culture conditions such as heterotrophic, mixotrophic and photoautotrophic conditions were investigated for growth, total photosynthesis ratio and flowering. Survival rate of propagules after transplanting was higher in photoautotrophic propagules than in the heterotrophic and mixotrophic ones. Total photosynthesis was higher plantlets growth in photoautotrophic (154 mg$CO_2$.mgDW$^{-1}$ h$^{-2}$ ) those grown than in mixotrphpic (148 mg$CO_2$.mgDW$^{-1}$ h$^{-2}$ ) and heterotrophic (102 mg$CO_2$.mgDW$^{-1}$ h$^{-2}$ ) 30 days after transplanting into fields. Day to flowering of the plant cultured in photoautotrophic condition was shortened by 7~10 days than those of heterotrophic and mixotrophic ones. Length of the petiole, number of leaves, leaf area and chlorophyll content were also increased.

• Korean Journal of Environmental Biology
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• v.18 no.4
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• pp.403-409
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• 2000

Surface and bottom water samples were collected from 10 stations located in the coastal area of Tongyong in April, August and October 2000. Distribution of heterotrophic bacteria, coliform bacteria and fungi in the sea water samples was investigated by measuring the corresponding viable cell number according to the plate counting method. Heterotrophic bacteria in the surface water counted 3.1$\times$10$^2$- 4.0$\times$10$^3$cfu ml$\^$-1/, 2.7$\times$10$^3$- 1.2$\times$10$\^$5/cfu ml$\^$-1/ and 1.3$\times$10$^2$- 7.2$\times$10$^2$cfu ml$\^$-1/ in April, August and October, respectively. The cell number of coliform bacteria in the surface water amounted to 0-1.5$\times$10$^1$cfu ml$\^$-1/, 3.5$\times$10$^1$- 5.2$\times$10$^3$cfu ml$\^$-1/ and 0-1.8$\times$10$^2$cfu ml$\^$-1/ in April, August and October, respectively. As for fungi, the cell number in the surface water was 0-3.0$\times$10$^1$propagules ml$\^$-1/, 3.0$\times$10$^1$- 8.0$\times$10$^1$ propagules ml$\^$-1/ and 0-2.2$\times$10$^1$ propagules ml$\^$-1/ in April, August and October respectively. The surface water samples from the station 3 in August were added with feed stuffs for fish as much as 0.01 gl$\^$-1/, 0.1 gl$\^$-1/ and 1 gl$\^$-1/ and cultured at 5$\^{C}$, 15$\^{C}$, 25$\^{C}$ and 35$\^{C}$. Microbial cells were not isolated at all when the culturing temperature was 5$\^{C}$. However, the microbial cell number increased significantly in all the surface water samples containing 1 gl$\^$-1/ of the feed stuffs when cultured at 15$\^{C}$, 25$\^{C}$ and 35$\^{C}$

• The Korean Journal of Mycology
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• v.13 no.4
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• pp.195-201
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• 1985

Numbers of total bacteria and fungal propagules were highly populated in the soil of diseased plot in Gumsan, whereas numbers of actinomycetes were high in the soil of healthy plot in Goesan. In microbial fluctuation of different soil conditions four weeks after amended with various plant materials, bacteria were decreased in the soil amended with various plant materials as compared with non-amended soil except for Goesan. On the contrary, numbers of fungal propagules were increased amended with onion and potato stalk in two soils at different conditions, and also the propagules were enhanced in the soil amended with various plant materials in general. Higher numbers of bacteria and fungal propagules were observed in the diseased replanted plot in general, but germination rate of fungal spores relatively reversed against the microbial population. Alternaria panax was not affected much in their germination by natural soil condition, while Fusarium spp. were affected in their germination by natural soil. Natural soil showed a fungistatic effect against four fungal spores.

• Korean Journal of Microbiology
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• v.19 no.4
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• pp.154-162
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• 1981

An investigation of the soil microfungal population in the paddy fields of two locations around Seoul was made at four seasons. By the dilution plate method, a total number of propagules of the microfungi pergram of soil was recorded as $10^4$ at the upper layer (0.10cm depth) followed by the middle (10-20cm depth) and the lower layer(20-30 cm depth). The highest number of fungal propagules was $11.0\;{\times}\;10^4$ at the upper layer of the soil collected in autumn. The decreasing tendency of the number of fungal propagules was depend on the increasing depth in paddy fields. Seasonal fluctuation of the fungal population was shown from the highest density of fungal colonies on the plate in autumn season and the lowest one in winter, indicating that the autumn is best season for fungal growth. Generally, the number of the species of Talaromyces in the paddy soils was found to be very high, particularly in autumn, while comparatively low in winter. The highest number of the species of Talaromyces was $6.5\;{\times}\;10^4$ propagules per gram of soil in Yukkog-dong in autumn and the lowest was $0.5\;{\times}\;10^4$ in Shinwon-dong in winter. It is assumed that these fungi grow well also in the warm to the hot seasons.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.257-260
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• 1982

During the rice storage at $28^{\cir}{\pm}1^{\cir}C$ and $60{\sim}70%$ R.H., the moisture content of rice, was increased max. 1. 6% by the activity of rice weevil. The growth of Asp. repens was not affected, while Asp. niger was inhibited after the appearance of its second generation adults. The development of rice weevil was generally accelerated by both of Asp. repens and Asp. niger, but decelerated at higher density of Asp. niger($1.6{\times}10^4$ propagules/g). The total number of rice weevil showed no significant difference during six weeks.