• Korean Journal of Medicinal Crop Science
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• v.22 no.5
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• pp.363-368
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• 2014

This study was conducted to find out the optimum composition of nursery soil for raising seedling of ginseng (Panax ginseng C. A. Meyer). Total 9 kinds of raw materials were used such as peat-moss, perlite, leaf mould, rice bran, gull's guano, castor-oil plant bark, palm bark, cow manure and chicken manure for optimum composition of nursery soil in ginseng. Occurrence of damping-off in ginseng was lowered about 50% in nursery soil type 1, 2 and 4 than in other types nursery soil in June, and occurrence rate of rusty root also lowest in nursery soil type 1. As the salinity of nursery soil increased, so did the occurrence of physiological disorder in ginseng seedling. The cause of salinity increasing in nursery soil has closely relation to $NO_3-N$, $P_2O_5$ and $Na^+$ content. Plant height, root length, diameter and weight were longer and heavier in nursery soil type 1 (mixing ratio of peat-moss, perlite and leaf mould was 50 : 20 : 30 based in volume) than in other types of nursery soil. So nursery soil type 1 was selected for raising seedling of ginseng. pH and electric conductivity (EC) of selected nursery soil type 1 was 5.55 and 0.13 dS/m. Contents of $NO_3-N$ and $P_2O_5$ were 21.0 and 40.0 mg/L, and $K^+$ 0.36, $Ca^{2+}$ 3.38, $Mg^{2+}$ 2.01 and $Na^+$ $0.09cmol^+/L$, respectively.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.14-20
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• 2015

Coastal plant species, Plantago camtschatica Cham. native to the coastal region of the East Sea were sampled and then morphologically different 20 endophytic fungal strains were purely isolated. Phylogenetic analysis of isolates was done by the Bayesian program based on sequenced internal transcribed spacer (ITS-rDNA) region. Culture filtrates of each of 20 isolates were treated to Waito-c rice (WR) seedlings for verifying plant growth-promoting activity, respectively. As the results, E/PC/10/1 strain showed the highest plant growth-promoting activity among them. The culture filtrate of the strain E/PC/10/1 was revealed as containing gibberellins ($GA_1$, $GA_3$, $GA_4$) by using HPLC, and gas GC/MS with selected ion monitoring (SIM). Finally, this strain was identified as novel Penicillium spinulosum species that producing new GAs with microscopic observation and further molecular analysis with beta-tubulin gene sequence.

• Journal of Life Science
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• v.21 no.11
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• pp.1619-1624
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• 2011

Endophytic fungal strains were isolated from the roots of six species plants in the Dokdo islands. Native plant samples, such as Artemisia japonica, Chenopodium album and Solanum nigrum were isolated from Dongdo, and those such as Cyrtomium falcatum, Dianthus longicalyx and Tetragonia tetragonoides were isolated from Seodo. In total, thirty two fungal strains were isolated from these native plants. To identify the fungal strains, polymerase chain reaction (PCR) amplification of internal transcribed spacer (ITS: containing ITS1, 5.8s and ITS2 region) regions was done with universal primers ITS1 and ITS4. Endophytic fungi of four species were isolated from A. japonica, eight species from C. album, three species from S. nigrum, three species from C. falcatum, three species from D. longicalyx and eleven species from T. tetragonoides. Culture filtrates (CF) of isolated endophytic fungi were used to treatwaito-c rice seedlings to test plant growth-promoting activity. As a result of bioassay, Ca-5-2-2 strain isolated from C. album expressed highest plant growth-promotion activity. Of all the endophytic fungi isolated, Penicillium sp., Fusarium sp. and Aspergillus sp. were the most abundantly distributed fungal strains in the six plants used in this study.

• Journal of Life Science
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• v.23 no.1
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• pp.95-101
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• 2013

In this study, plant samples of five species were collected from the Dokdo islands in South Korea. Plant samples such as Asparagus schoberioides, Corydalis platycarpa, Festuca rubra, Sedum oryzifolium, and Setaria viridis were collected from the Dongdo and Seodo. Endophytic fungal strains were isolated from the roots of five plants from the Dokdo islands. Thirty-three fungal strains were isolated from these native plants. All the endophytic fungi were analyzed by internal transcribed spacer (ITS) sequencing (ITS containing ITS1, 5.8s, and the ITS2 region). Waito-c rice seedlings were treated with fungal culture filtrates to test their plant growth-promoting activity. A bioassay of the D-So-1-1 fungal strain isolated from S. oryzifolium confirmed that it has the highest plant growth-promoting activity. All the endophytic fungi belong to four orders: Eurotiales (86%), Capnodiales (3%), Hypocreales (4%), and Incertae sedis (7%). The endophytic fungi were classified as Ascomycota, which contained Aspergillus (12%), Cladosporium (3%), Eurotium (3%), Fusarium (18%), Microsphaeropsis (6%), and Penicillium (58%) at the genus level.

• Korean journal of applied entomology
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• v.20 no.3 s.48
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• pp.173-175
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• 1981

New screening method of varietal resistance by isotope $^{32}P$ was examined in these experiments. Insects were fed for 24 hrs. in the vials, with rice seedlings absorbed the solution if $0.6\~7{\mu}\;Ci\;^{32}P$ for 24 to 48 hrs. Feeding amounts of 3 species of plant-hoppers at the different stages and duration of infestation were investigated for effective process of screening method of the varietal resistance using isotope $^{32}P$. Feeding amount of $^{32}P$ of brown plant-hopper was observed for the different varieties. The results may be summarized as follows: 1. Brown planthopper fed greatest and the feeding amount were increased in order of white-backed planthopper and small brown planthopper. Female hoppers fed more than male. 2. Feeding amount was increased in order of adult, 5th instar, adult, 4th instar, 3rd instar 2nd instar and 1st instar. The duration of $24\~48\;hours$ is considered sufficient for insect infestation. 3. New screening method by $^{32}P$ was compared with seedling bulk screening method in view of feeding amount and plant reaction. Feeding amount of $^{32}P$ by brown planthopper in Milyang 47, resistant variety to this insect, was very low, while in TN 1, susceptible variety, it was very high about one hundred tines of Milyang 47.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.32-39
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• 2016

Coastal plant species Tetragonia tetragonoides (Pall.) Kuntze native to the Dokdo islands was sampled and then 17 endophytic fungi were purely isolated based on morphological differences. The fungal isolates were characterized by their growth properties under NaCl concentration or pH gradient. Culture filtrates of the 17 fungal isolates were treated to Waito-c rice (WR) seedlings for verifying plant growth-promoting activity. As the results, YH103 strain showed the highest plant growth-promoting activity among them. Phylogenetic analysis of the isolates was done by the maximum likelihood method based on partial internal transcribed spacer region (ITS region: contaning ITS1, 5.8S, and ITS2), beta-tubulin (BenA), and calmodulin (CaM) gene sequences. Chromatographic analysis of the strain YH103 culture filtrate showed the existence of gibberellins ($GA_4$, $GA_7$, $GA_8$, and $GA_{19}$). Finally, the strain YH103 was identified as Aspergillus tubingensis by microscopic observation and molecular analysis and, to our knowledge, this is the first report of GAs producing A. tubingensis.

• Korean journal of applied entomology
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• v.13 no.1 s.18
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• pp.19-23
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• 1974

Since Tongil has been cultivated widely in farmers' fields, the variety is known to be highly resistant to existing races of Pyricularia oryzae in Korea. However, Tongil and the sister lines were moderately susceptible to race IA-65, which was isolated from Tongil at the blast nursery of the College of Agriculture, Seoul National University, 1972. In field tests of 1973, pathogenic reactions of IR lines at the isolated nursery, where IA-65 had been inoculated, were significantly higher than those at the farm nursery. When seedlings of 196 IR lines were inoculated with IA­65, about $30\%$ of the IR lines including IR667-98 were moderately susceptible. Among the 30 isolates of P. oryzae obtained mostly from indicas, 12 were also differentiated in 1973 as IA group known to be the most prevalent races at IRRI in the Philippines, where Tongil has been highly susceptible. This IA group was also pathogenic to Tongil in greenhouse experiments. The race group causing moderately susceptible to Tongil should be new in Korea, since no occurrences of the race IA have ever been reported previously from the areas where japonica types of rice are cultivated. Because some races of P. oryzae present in Korea are pathogenic to Tongil and because these races may become prevalent in the fields, the reaction of Tongil must be continuously monitored.

• Mycobiology
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• v.43 no.4
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• pp.373-383
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• 2015

Five halophytic plant species, Suaeda maritima, Limonium tetragonum, Suaeda australis, Phragmites australis, and Suaeda glauca Bunge, which are native to the Muan salt marsh of South Korea, were examined for fungal endophytes by sequencing the internal transcribed spacer (ITS) region containing ITS1, 5.8S rRNA, and ITS2. In total, 160 endophytic fungal strains were isolated and identified from the roots of the 5 plant species. Taxonomically, all 160 strains belonged to the phyla Ascomycota, Basidiomycota, and Zygomycota. The most dominant genus was Fusarium, followed by the genera Penicillium and Alternaria. Subsequently, using 5 statistical methods, the diversity indices of the endophytes were determined at genus level. Among these halophytic plants, P. australis was found to host the greatest diversity of endophytic fungi. Culture filtrates of endophytic fungi were treated to Waito-C rice seedlings for plant growth-promoting effects. The fungal strain Su-3-4-3 isolated from S. glauca Bunge provide the maximum plant length (20.1 cm) in comparison with wild-type Gibberella fujikuroi (19.6 cm). Consequently, chromatographic analysis of the culture filtrate of Su-3-4-3 showed the presence of physiologically active gibberellins, $GA_1$ (0.465 ng/mL), $GA_3$ (1.808 ng/mL) along with other physiologically inactive $GA_9$ (0.054 ng/mL) and $GA_{24}$ (0.044 ng/mL). The fungal isolate Su-3-4-3 was identified as Talaromyces pinophilus.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.140-144
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• 2001

Field investigations were initiated to determine possible new 'ssam' vegetable that could be grown during the summer season in highland. Korean 'ssam' means cooked rice in vegetables. The 'ssam' vegetable is called that those leaves has been used for wrapping at meal. Seventeen leafy vegetables were studied, including chard (Beta vulgaris L. var. flavescens DC.), leaf broccoli (Brassica oleracea L. var. italica), Chinese leek (Allium tuberosum Rottl.), Japanese hornwort (Cryptotaenia japonica Hassk), red leaf mustard (Brassica juncea L.), green leaf mustard (Brassica juncea L.), leaf parsley (Petroselinum crispum Nijim), pakchoi (Brassica campestris L. ssp. chinensis Jusl.) tatsoi (Brassica campestris var. narisoma), kale (Brassica oleracea var. acephala), collard (Brassica oleracea var. acephala), Korean mint (Agastache rugosa O. Kuntze), romaine lettuce (Lactuca sativa L. var. longifolia Lam.), red leaf chicory (Cichorium intybus L. var. folisum), red chicory (Cichorium intybus L. var. folisum), green leaf chicory (Cichorium intybus L. var. folisum), and sprouting broccoli (Brassica oleracea L. var. italica). Date of the first harvest in 1999 was July 10th in chard, leaf broccoli, red mustard, mustard, leaf parsley, pakchoi, tatsoi, kale, collard, Korean mint, red leaf chicory, red chicory, green leaf chicory, and sprouting broccoli. Date of the first harvest for Chinese leek, Japanese hornwort, and romaine lettuce was from the middle of June to the late of August. Based on ratings on marketable yield, we found good leaf shape, taste and yield in chard, red leaf mustard, green leaf mustard, pakchoi, tatsoi, romaine lettuce, red leaf chicory, red chicory, and green leaf chicory. Even though the most of all these vegetables were obtained high scores by test panels in shape, taste and quality, but some of them revealed inadequate leaf size as a 'ssam' vegetable. That problem will be solved by control of harvesting time. On the basis of this observation, chard, red leaf mustard, green leaf mustard, pakchoi, tatsoi, romaine lettuce, red leaf chicory, red chicory, and green leaf chicory were rated as promising 'ssam' vegetable by analysis of profits, adaptation, and quality.

• Korean Journal of Weed Science
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• v.8 no.2
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• pp.187-198
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• 1988

The second leaves from 30 days old seedlings of two rice cultivars which were selected as tolerant (cv. Chokoto) and susceptible (cv. Weld pally) cultivar were soaked in the concentration of $10^{-6}$, $10^{-5}$, $10^{-4}$ and $10^{-3}M$ of oxyfluorfen for 10, 15 and 22hrs and anatomical characteristics were abserved. Dipping to the solutions were carried out either directly to the attached leaves or to the seperated leaves. Development of any symptoms in epidermis, bundle sheath, mesophyll cells and bulliform cells were microscopically inspected. Both cultivars showed reductionin leaf thickness, but the susceptible ones was more sensitive than the tolerant. The degradation and disappearance of epidermal cell layer, breakage of bundle sheath cells, shrinkage of mesophyll cells and disappearance of bulliform cells were general response as affected by oxyfluorfen treatment. The susceptible cultivars showed such responses at the concentration of $10^{-5}M$ for 10 hrs while tolerant ones $10^{-3}M$, for 10 hrs. Those treatments were more effective in seperated leaves than in attached ones. The epicuticular wax layer of leaves treated as above for 20 hrs was inspected by SEM. Weld pally, the susceptible cultivar (Weld pally) showed rapid cleavage of wax layer under $10^{-5}M$ concentration while the tolerant (Chokoto) showed only minor damage on wax layer at the concentration of $10^{-3}M$.