• Journal of Life Science
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• v.31 no.6
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• pp.537-542
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• 2021

Schisandra nigra Max., a dioecious plant native to Jeju Island in Korea, is cultivated on a small scale for fruit production. As fruit-producing female individuals are generally considered to be more valuable than male, early identification of plant sex at the seedling stage is important. In this study, a sequence-characterized amplified region (SCAR) marker associated with a female-specific region in the genome of S. nigra was investigated. Of 120 randomly amplified polymorphic DNA (RAPD) primers, one primer (OPB-03) consistently amplified a 749 bp band in female plants. The female-specific PCR product was isolated and cloned, and the nucleotide sequences were then determined. Southern hybridization performed using the female-specific fragment as a probe produced positive signals only in genomic DNA from the female plants. This result revealed that the 749 bp segment of DNA was present in the genome of female plants but absent in the genome of male plants. A SCAR primer pair was designed based on the RAPD marker to amplify a 436 bp fragment in the genomic DNA of female plants. This primer pair amplified the expected size of DNA fragment in female plants and four monoecious individuals collected from a natural population. The SCAR marker identified in this study can be used to distinguish female-flowering individuals at the seedling stage.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.295-301
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• 2023

This study was conducted to determine the optimal dipping time and concentration of gibberellin for improving the growth and quality of domestic cultivar 'Seolhyang' strawberry when using runner plants. Strawberry runner plants were collected on November 10th and soaked in GA₃ concentrations of 50, 100, and 150 mg·L^-1 for 30 and 60 minutes, respectively. After 75 days of planting, the growth results showed that in the 30-minute, 50 mg·L^-1 treatment, the crown diameter was thicker and the T/R ratio was lower, indicating better plant vitality. Runner length increased with lower gibberellin concentrations, particularly promoting vegetative growth. Photosynthetic efficiency was more influenced by gibberellin concentration than dipping time, and using concentrations above a certain threshold acted as a stress factor for runner plants, leading to decreased photosynthetic efficiency. For enhancing seedling growth, soaking with 50 mg·L^-1 of gibberellin for 30 minutes was found to be optimal. This study verified the effects of gibberellin treatment on strawberry runner plants to improve plant growth and quality, providing useful basic data for using gibberellin.

• Korean Journal of Environmental Biology
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• v.26 no.1
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• pp.15-21
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• 2008

Ionizing radiation causes many alterations in photosynthetic machineries. However, there is no information about effects of ionizing radiation on the development of photosynthetic machineries in plants. We investigated the greening of etiolated mung bean seedlings after gamma-irradiation of 50 to 300 Gy. The irradiation inhibited seedling growth with great dependence on the radiation dose. In particular, growth of stems was more affected than that of hypocotyls. Irradiated leaves showed inhibition in growth, aberration in morphology, and yellowing in color depending on the radiation dose. Contents of photosynthetic pigments such as chlorophylls and carotenoids were significantly decreased in the irradiated leaves. The apparent electron transport rate for photosynthesis, ETR, was similarly changed depending on the radiation dose. However, the maximal photochemical efficiency of Photosystem II (PSII), Fv/Fm, was little affected by the irradiation. Moreover, the 50-Gy seedlings maintained the control level of light saturating for photosynthesis and showed slightly higher Fv/Fm values in spite of significant decreases in the photosynthetic pigment content and ETR. These results suggest that the inhibition of the overall photosynthetic capacity couldn’t be causally relatqaed with the repression in the initial development of irradiated seedlings and that the overall photosynthetic machineries can develop and work to some extent as a concerted system for photosynthesis even after exposure to acute doses of ionizing radiation.

• Journal of Ginseng Research
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• v.28 no.4
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• pp.211-214
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• 2004

This study was carried out to find out the optimum hardening condition for ginseng plantlets redifferentiated by tissue culture method. While a lot of root hair were observed on the root of seedling grown on the soil, few root hair were observed on the root of plantlet redifferentiated in vitro. On the medium solidified with $0.1{\%}$ phytagel, root hair was not observed and root weight, root width and laternal root development were also very poor. While raising the phytagel concentration on the media, root hair began to increase and root weight, root width and latemal root development were improved. Vascular tissue of plantlet grown on the medium with $0.1{\%}$ phytagel was very poor, but that of plantlet grown on the medium with $0.8{\%}$ phytagel was very good.

• Journal of Korean Society of Forest Science
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• v.67 no.1
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• pp.10-16
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• 1984

Containerized Quercus acutissima seedlings were inoculated with vegetative mycelial inoculum of Pisolithus tinctorius and were grown in a green-house. The ectomycorrhizal fungus, P. tinctorius (Pt) increased growth of the container-grown oak seedlings. Of three treatments, Pt inoculation stimulated remarkably primary lateral roots, shoot growth, and root collar diameter and leaf area development, compared with either non-inoculated or natural soil treatment. In addition, Pt-inoculated seedlings produced ectomycorrhizae, by 71.1 percent. However, noninoculated and naturally grown seedlings were free of natural ectomycorrhizal. Ectomycorthizal roots developed more abundantly in the middle portion of the container than in the top or bottom portions.

• Journal of Plant Biotechnology
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• v.6 no.2
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• pp.77-85
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• 2004

Development of efficient plant regeneration and genetic transformation protocols (using the Particle Inflow micro-projectile Gun and the shoot-tips as target tissue) of Sorghum bicolor (L.) Moench in terms of expression of the reporter gene, $\beta$-glucuronidase(uidA) is reported here. Two Indian cultivars of sorghum were used in the study, viz. M-35-1 and CSV-15. Plant regeneration was achieved from one-week-old seedling shoot-tip explants via multiple-shoot-clumps and also somatic embryos. The multiple-shoot-clumps were produced on MS medium containing BA (0.5, 1.0 or 2.0 mg/$L^{-1}$), with biweekly subculture. Somatic embryos were directly produced on the enlarged dome shaped expansive structures that developed from shoot-tip explants (without any callus formation) when cultured on MS medium supplemented both with BA (0.5, 1.0 or 2.0 mg/$L^{-1}$) and 2,4-D (0.5 mg/$L^{-1}$). Whereas each multiple-shoot-clump was capable of regenerating more than 80 shoots via an intensive differentiation of both axillary and adventitious shoot buds, the somatic embryos were capable of 90% germination, plant conversion and regeneration. The regenerated shoots could be efficiently rooted on MS medium containing 1.0mg/$L^{-1}$ IBA and successfully transplanted to the glasshouse and grown to maturity with a survival rate of 92%. The plant regeneration efficiency of both the genotypes were similar. After the micro-projectile bombardment, expression of uidA gene was determined by scoring blue transformed cell sectors in the bombarded tissue by an in situ enzyme assay. The optimal conditions comprising a helium pressure of 2200 K Pa, the target distance of 11 cm with helium inlet fully opened and the use of osmoticum have been defined to aid our future strategies of genetic engineering in sorghum with genes for tolerance to biotic and abiotic stresses.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.263-268
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• 1983

In a survey of seed-borne mycofloras of Glycine max, 21 species have been isolated. Alternaria tenuis, Aspergillus spp., Cercospora kikuchii, Penicillium spp. and Fusarium spp. were the predominant fungi. C. kikuchii was isolated more often from purple stained seed than from unstained seed, and Fusarium spp., Phomopsis sp., Aspergillus spp. and Penicillium spp. were isolated less frequently in stained than unstained seeds. In inoculation experiments, C. kikuchii, Colletotrichum dematitum, Phomopsis sp. produced mild to severe symptoms on leaves when suspension of their conidia and mycelia were sprayed on to plants. In soil inoculation experiments, Fusarium oxysporum, F. moniliforme and F. semitectum showed pathogenicity causing seed rot and seedling blight.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.281-291
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• 2010

The rice CHLH gene encodes the $Mg^{2+}$-chelatase H subunit, which is involved in chlorophyll biosynthesis. Growth of the chlorophyll-deficient oschlh mutant is supported by mitochondrial activity. In this study, we investigated the activity of mitochondrial respiration in the illuminated leaves during oschlh seedling development. Growth of mutant plants was enhanced in the presence of 3% sucrose, which may be used by mitochondria to meet cellular energy requirements. ATP content in these mutants was, however, significantly lowered in light conditions. Low cytosolic levels of NADH in illuminated oschlh mutant leaves further indicated the inhibition of mitochondrial metabolism. This down-regulation was particularly evident for oxidative stressresponsive genes in the mutant under light conditions. Hydrogen peroxide levels were higher in oschlh mutant leaves than in wild-type leaves; this increase was largely caused by the impairment of the expression of the antioxidant genes, such as OsAPXl, OsRACl, and OsAOXc in knockout plants. Moreover, treatment of mesophyll protoplasts with ascorbic acid or catalase recovered ATP content in the mutants. Taken together, these results suggest that the light-mediated inhibition of mitochondrial activity leads to stunted growth of CHLH rice seedlings.

• Korean Journal of Medicinal Crop Science
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• v.22 no.2
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• pp.154-159
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• 2014

This study was carried out in order to investigate the early growth and root development characteristics of Atractylodes japonica container seedling. Experiment was performed by light intensity (100%, 60%, 25% and 10% of full sunlight). Height was surveyed well under 25% of full sunlight (overall 11.013.0%). Root collar diameter was the highest in the full sunlight (7.52 mm). It was the highest fresh weight (1.52 g, 0.92 g, 0.90 g and 3.34 g) under 25% of full sunlight, root dry weight was getting higher in the higher light level and the highest in the full sunlight (0.13 g). Total root length, root project area, root surface area and root volume were the highest under 25% of full sunlight (434.7 cm, $17.4cm^2$, $54.7cm^2$, $0.55cm^3$, respectively) and the lowest under 10% of full sunlight. As a result of surveying the whole experiment, A. japonica is judged nicely by maintaining 25% of full sunlight, excepting 10% of full sunlight. And light levels during the early growth are overly important to improve early growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.287-294
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• 2006

Germination and early elongation of rice after germination were investigated in anoxic air treatment, nitric oxide gas treatment, and six concentrations of mercuric chloride solutions to determine the effects of limited oxygen environment, nitric oxide, and inhibited water flux through cell membrane in $17^{\circ}C$. Anoxic air treatment affected germination of tested six varieties very little. However root elongation rates were severely inhibited while shoot growth was affected less. Reductions in shoot and root elongations demonstrated genotypic variations. Nitric oxide delayed the germination of rice even though it didn't affect the final percent germination. Elongations of root and shoot were inhibited in nitric oxide treatment. The inhibitor effect of nitric oxide on the shoot elongation of rice was less severe, while nitric oxide completely inhibited the root emergence of rice. Concentrations of $HgCl_2$ greater than $300{\mu}M$ dramatically reduced the rate and percentage of germination when compared to distilled water treatment. The reduced percent germination showed the greatest variation among rice varieties in $500{\mu}M$ solution of mercuric chloride. Ansanbyeo, Jinheung, and Odaebyeo were affected less by $HgCl_2$, Nonganbyeo and Sangmibyeo were intermediate, and the germination of Andabyeo was greatly reduced by $HgCl_2$. Root elongation of germinated rice seedlings was more sensitive to oxygen deficits, nitric oxide, and $HgCl_2$ treatments than germination and shoot elongation. In conclusion, poor seedling establishment of rice sown in flooded paddy soils, in which the oxygen supply to the seeds is restricted, appears to the result of limited root elongation rate.