• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.317-322
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• 2009

Healthy seedling generation is the major concern in overcoming adverse effects of biotic and abiotic stresses during tender stage of development in vegetables and horticultural crops. Because of this, priority is given to research leading to the generation of healthy seedlings in crops subjected to transplanting and bedding. In this study, growth pouch experiments were conducted to determine the effect of inoculation of six different strains of Methylobacterium sp. namely, M. oryzae CBMB20, M. phyllosphaerae CBMB27, M. suomiense CBMB120, and Methylobacterium strains CBMB12, CBMB15 and CBMB17 on the seedling development of the vegetable crops cabbage, Chinese cabbage and cucumber; and horticultural crops tomato and red pepper. Crops treated with the test strains generally showed higher seedling dry matter accumulation compared to the control. Significantly higher accumulation was exhibited by CBMB12, CBMB17, and CBMB20 in cabbage, as well as for CBMB27 and CBMB120 on tomato and Chinese cabbage, respectively. Furthermore, all the strains promoted root elongation in cucumber and tomato seedlings while in Chinese cabbage and red pepper, root elongation was observed with CBMB120 and CBMB12 inoculation, respectively. Large scale nursery study is needed to develop a thorough protocol for healthy seedling development with the use of these strains.

• Korean Journal of Plant Tissue Culture
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• v.28 no.2
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• pp.103-108
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• 2001

The in vitro plantlets of cassava (Manihot esculenta Crantz cv. MColl 22) could be regenerated from nodal explant cultures in a liquid MS basal medium containing 0.01 mg/L zeatin for 2 weeks. The plantlets of 1.5∼2.5 cm in shoot length were transplanted to a glass bottle containing fine sand and acclimated under non-sterile conditions after excising their intact roots by: 1) prune leaving roots base of 1∼1.5 cm; 2) complete removal of roots; and 3) cutting off the rooting zone. The majority of in vitro-formed intact roots continued growth after transferred to soil, and all of the damaged roots stopped further growth. The plantlets with excised roots began to develop new roots within 7∼10 days after being transferred to a glass bottle, and a few of the pruned roots developed lateral roots from the remaining portion. Pruning and removal of in vitro roots resulted in a high survival rate (>87%), and did not significantly affect ex vitro root regeneration and acclimation, but the plantlets in which the rooting zone had been cut-off showed 73% survival rate. Pruning or removal of in vitro roots before transfer of plantlets is recommended for useful method of commercial micropropagation because of easier handling and high survival rate of plantlets.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.19-25
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• 2012

This study is an analysis of the initial growth of Adenophora triphylla var. japonica, and the growth of their above- and underground parts by means of shading treatment in order to provide a basic data that can be used in growing A. triphylla var. japonica in mountainous area. As for the rate of sprouting by shading treatment, 25% treatment and control showed the earliest sprouting. The leaf unfolding had the same order as the rate of sprouting. The analysis of the characteristics of growth of above- and underground parts showed that the growth of aboveground parts are excellent in the 25% treatment. 25% treatment were shown to be the longest in the total length of roots and root projection area. Control were discovered to be the most prominent in root surface area, root diameter, and root volume. 75% and 25% treatment in distribution by root diameter showed 72.4% and 69.5% of very fine root(>0.5mm), respectively.

• Journal of Plant Biotechnology
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• v.37 no.3
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• pp.337-342
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• 2010

To establish the optimum conditions of in vitro plant regeneration, the leaf, rhizome, and root explants of Belamcanda chinensis were cultured on the MS medium supplemented with different concentration of 2,4-D and BA. The callus induction was more effective in the root explants than the leaf and rhizome explants, and was the best on MS medium containing 3.0 mg/L 2,4-D or 1.0 mg/L 2,4-D and 3.0 mg/L BA. The highest numbers of shoots were regenerated when callus were cultured on MS medium containing 3.0 mg/L 2,4-D for 4 weeks. However, the multiple shoots were induced on MS medium supplemented with the combination of 2,4-D and BA. The normal root formation from shoot was effective on the MS medium lacking any plant growth regulators. For acclimatization, the regenerated plantlets were cultured on MS medium without sucrose and plant growth regulators for 2 weeks, and then transferred to the pot.

• Research in Plant Disease
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• v.20 no.2
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• pp.87-94
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• 2014

The fungus Cylindrocarpon destructans is the cause of root rot in many ginseng production areas in Korea. A total of 57 isolates of C. destructans were recovered from diseased roots in a survey of ginseng-growing fields from 2011-2012. Among these isolates, 37% were classified as highly virulent (causing lesions on unwounded mature roots) and 61% were weakly virulent(causing lesions only on previously wounded roots). Radial growth of highly and weakly virulent isolates on potato dextrose agar was highest at $20^{\circ}C$ and there was no growth at $35^{\circ}C$. Mycelial mass production was significantly (P = 0.05) lower at pH 7.0 compared with pH 5.0. To study the effects of pH (5.0 and 7.0) and wounding on disease development, ginseng roots were grown hydroponically in nutrient solution. Lesions were significantly larger (P < 0.01) at pH 5.0 compared with pH 7.0 and wounding enhanced disease by a highly virulent isolate at both pHs. In artificially infested soil, 2-yearold ginseng roots were most susceptible to Cylindrocarpon root rot among all root ages tested (1 to 4 years) when evaluated using a combined scale of disease incidence and severity. Root rot severity was significantly (P<0.05) enhanced by increasing the inoculum density from $3.5{\times}10^2cfu/g$ of soil to $2.0{\times}10^3cfu/g$ of soil.

• Journal of Life Science
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• v.17 no.10
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• pp.1414-1418
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• 2007

This study was to examine the accumulated concentration of lead in the organ of Arabidopsis thaliana grown in the soil added three different concentrations of lead. The accumulated concentrations of lead in the stem of plant grown in the soil added official standard concentration of lead of pollutant exhaust notified by the Ministry of Environment (1 mg/l), concentration ten times higher than the official standard concentration (10 mg/l) and concentration fifty times higher (50 mg/l) were similar to the rate of increase between three different concentrations, and increased average 24% compared with normal plant stem. The accumulated concentrations of lead in the leaf of plant grown in the soil added three different concentrations of lead were increased average 57% compared with normal plant leaf. And accumulated concentrations of lead in the leaf was no significant difference according to increase of lead concentration added in the soil as stem, the rate of increase was similar to between three different concentrations. The accumulated concentrations of lead in the root of plant grown in the soil added official standard concentration of lead of pollutant exhaust and concentration ten times higher were increased average 114% compared with normal plant root, but increased about 861% in the concentration fifty times higher than the official standard concentration. This result contrast with the data of stem and leaf. The accumulated concentration of lead in the plant body of Arabidopsis thaliana was increased according to increase of lead concentration added in the soil. Especially, the accumulated concentration of lead in the plant body grown in the concentration fifty times higher than the official standard concentration was increased about 2.6 times than normal plant. These results show that lead contaminated within the soil was more accumulated in the root than the stem or leaf, and accumulated concentrations of lead in the stem and leaf were not increased in proportion to the concentration of lead in the soil, but very increased in proportion to the concentration in the root.

• The Korean Journal of Mycology
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• v.33 no.1
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• pp.30-34
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• 2005

Fifteen PGPF (plant growth promoting fungi) isolates were selected from 728 fungal isolates collected from rhizosphere of zoysiagrass in Korea. Identification of the 15 isolates was based on their morphological characteristics. They were classified as Gliocladium sp. (n=1), Penicillium sp. (n=5), Trichoderma sp. (n=3), Fusarium sp. (n=3), and unidentifed species (n=3). Of the 15 isolates, six (PF-31, PF-136, PF-238, PF-255, PF-395, PF-420) significantly promoted the growth of tomato seedlings, and three (PF-31, PF-101, PF-255) also promoted the growth of hot pepper and two (PF-31, PF-225) also promoted the growth of cucumber, The 15 PGPF isolates were divided into 4 groups based on root colonizing ability. Isolates PF-17, PF-101 and PF-225 were included in the group 1, which had high root colonizing ability.

• Journal of Sericultural and Entomological Science
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• v.26 no.1
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• pp.1-20
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• 1984

Effects of Foliar spray of Kinetin on the growth and metabolism of mulberry tree was investigated in this studies. The results are summarized as follows; 1. Appropriate level of Kinetin for the optimal growth of mulberry tree was 100ppm. 2. In the non-fertilizer, N, P, K, and N+P+K treated plots supplemented with Kinetin, the growth of mulberry tree was generally promoted, especially in the roots, in comparison to non-supplemented plots. The effect was notably outstanding in the N, and N+P+K treated plots. 3. The mechanism by which the growth of root is stimulated was fundamentally attributed to the hypertrophy of unit cells. 4. The chlorophyll contents of the leaves in the Kinetin supplemented plots were higher than that of the non-supplemented, especially in the N, and N+P+K treated ones. 5. Likewise, total sugar contents of Kinetin supplemented plots were higher than that of the non-supplemented. Particularly the N+P+K treated plots showed higher level of sugar contents. In other plots, there were no significant differences in the level of sugar contents. 6. The activity of GOT and GPT was higher in the Kinetin supplemented plots, particularly in the N, and N+P+K treateated. 7. The contents of ascorbic acid were increased in plots with kinetin supplement in the order of N+P+K>potassium>Nitrogen>phosphorus$\geq$non-fertilizer. 8. Difference between Kinetin treatment and non-treatment was not recognized in the contents of inorganic and organic compounds.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.89-94
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• 2004

Callus of Rhodiola sachalinensis A. Bor were induced from leaf explant on l/2MS solid supplemented with combination of auxin (2.4-D, NAA: 0.1∼2mg/L) and cytokinin (BA: 0.1∼0.2mg/L). The effects of various medium, culture conditions and phytohormones on the growth of callus were investigated. MS, WPM, B$_{5}$ medium and diluted or concentrated media (1/2X, 2X, 3X) were used to investigate the growth of callus on each media. Among these, the highest growth was observed when cultured in in 2B$_{5}$ medium containing 0.5mg/L NAA and 1mg/L BA, 3％ sucrose and 49.6 mM KNO$_3$ as nitrogen source, and 2.16mM NaH$_2$PO$_4$ as phoshate source at $25^{\circ}C$ in the dark. The calli cultured with 5％ sucrose produced high salidroside content (0.41％ on the basis of dry wt) than normal root (0.17％).

• Journal of Korean Society of Forest Science
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• v.84 no.3
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• pp.306-318
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• 1995

To investigate the effect of low light intensities and the inoculation of Frankia and/or Alpova diplophloeus on the symbioses development and their host growth, red alder(Alnus rubra Bong.) seedlings were grown in an air - filtered walk - in growth chamber with either $N_2$ - fixing Frankia inoculation or N - fertilization and live or dead spore inoculation of the ectomycorrhizal fungus A. diplophloeus(Zeller & Dodge) Trappe & Smith. When they were 20 weeks old, the seedlings were grown under three levels of light intensities of 680, 320 and $220{\mu}mol/m^2/s$ PPFD(photosynthetic photon flux density) for three weeks. PPFD of 220 significantly decreased the development of A. diplophloeus mycorrhizae and nodules, the rates of $N_2$ - fixation and $CO_2$ exchange, and the growth of tile seedlings. PPFD 320 significantly decreased the $CO_2$ exchange rate only. Frankia inoculation significantly increased mycorrhiza formation and seedling growth. Alpova inoculation significantly increased seedling growth but not nodule development and $N_2$ - fixation. None of the symbionts affected $CO_2$ exchange rates. Frankia was more critical for seedling growth and mycorrhizal development than the mycorrhizal fungus for seedling growth and nodule development.