• Journal of Forest and Environmental Science
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• v.21 no.1
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• pp.75-82
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• 2005

The experimental study was carried out to evaluate the performance of underplanted Pinus koraiensis 2-2 seedlings in the closed canopy natural deciduous forest. Overstory density effects on seedling survival and growth were assessed 7 years after underplanting. Seedling survival rate was 80%, average height was 0.9m with minimum of 0.3m and maximum of 2.1m, and average diameter at butt end was 1.7cm with minimum of 1.4cm and maximum of 3.5cm. Compared with the growth rate of the pine plantation after clearcutting, the growth performance of underplanted pine seedlings was so poor that the height growth was less than 30% and diameter growth was less than 20%. Even though the Pinus koraiensis seedlings would be shade tolerant, the establishment and performance of underplanted Pinus koraiensis seedlings could be promoted by more than 50% of canopy regulation that provide adequate light at the forest floor and should exhibit a strong positive response following overstory removal by tending operation.

• Journal of Plant Biology
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• v.8 no.1_2
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• pp.5-10
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• 1965

The effect of radioactive sulfur-35 on the growth and tissue respiration in rye, Secale cereale L., seedlings were studied in this investigation. The growth and respiration rate of the materials treated with the different intensities of radioactivity, represented by the different concentration(${\mu}c$) of radioactive sulfur were shown similar effects in treated groups as those of Gamma-ray or X-ray irradiation on plant materials. However, in the groups of ($0.1{\mu}c$ and ($0.4{\mu}c$ S35-solution, the growth and respiration rate were stimulated somewhat more clearly than in case of control. And the higher concentration groups, $1.6{\mu}c$, $6.4{\mu}c$, and $25.6{\mu}c$ were depressed of the growth and tissue respiration rate. The present data could be explained on the basis that the higher concentration treatments with the radioactive isotope did produce injury to the plant metabolism generally, but the moderate treatment would stimulate to the plant growth and tissue respiration.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.36-43
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• 2016

With transient flooding followed by poor or slow drainage plant roots may become reduction conditions because the root zone was fully filled with water. This study was examined the effects of calcium treatment in the early growth stage on biochemical changes in leaves and roots of melon (Cucumis melo L.) seedlings kept under flooding condition for 72 h. The activities of lactate dehydrogenase more gradually enhanced in the roots than those of leaves of melon seedlings treated with calcium. The activities of alcohol dehydrogenase associated with alcohol fermentation under low oxygen conditions continuously increased in the leaves and roots of seedlings untreated with calcium under flooding at least 72 h but those was constant within at least 12 h in treated with calcium. These results showed that calcium supplying in the early growth stage mitigated alcohol fermentation of melon seedlings kept under flooding condition for 72 h. Activities of nitrate reductase and acid phosphatase in the leaves and roots of seedlings in treated with calcium somewhat higher than those of non-treated with calcium. The activities of sucrose phosphate synthase and fructose-1,6-bisphosphatase of leaves of seedlings in treated with calcium more higher than those of non-treated with calcium. These results indicated that calcium nutrition mitigate the reduction of activities of some enzymes of melon seedling kept under flooding condition for 72 h.

• Korean Journal of Plant Resources
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• v.26 no.6
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• pp.701-708
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• 2013

To test the quality change of seedlings of three domestic medicinal plants raised in plug trays, a short term storage experiment was conducted. Seedlings were kept in growth chambers for two weeks at 4 or $8^{\circ}C$ temperature combined with 0 or $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD. Quality of glasshouse-raised seedlings was assessed after two weeks of cold storage in the growth chamber and one week of acclimation in the greenhouse. After two weeks of storage in the growth chamber of Perilla frutescens var. acuta Kudo, plant height was the greatest in the treatment $8^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD. Internode length of P. frutescens var. acuta Kudo was the greatest in the treatment of $4^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD. After one week of acclimatization in a glasshouse, the growth and development, such as plant height, internode length and leaf size, were greater in the $8^{\circ}C$ combined with $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD than in the other treatments. After two weeks of storage in the growth chamber of Sophora tonkinensis, plant height increased more in the treatment of $4^{\circ}C$ than $8^{\circ}C$. After one week of acclimatization in a glasshouse, number of leaves did not change in the treatment of $4^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD, but it increased in the other treatments. Leaf width increased more under the dark than light condition. Leaf length did not observably change in any treatments. After two weeks of storage in the growth chamber, plant height of Angelica gigas Nakai was the greatest in the treatment of $8^{\circ}C$. Number of leaves was the greatest in the treatment of $8^{\circ}C$. Leaf growth was greater under dark than light condition. These results suggested that optimal storage environment was $8^{\circ}C$ combined with $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD for P. frutescens var. acuta Kudo, and $4^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD for S. tonkinensis and A. gigas Nakai. Hence, proper combination of temperature and PPFD were necessary for better storage, and acclimatization and growth, thereafter, of the plug seedlings of theses plant species.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.313-324
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• 2020

This study investigated the environmental location effects that Larix kaempferi and mixed forests had on the early growth of wild-simulated ginseng (Panax ginseng C. A. Meyer) seedlings. Experimental plots were created in Larix kaempferi and mixed forests, and confirmed the location environments and growth characteristics of wild-simulated ginseng seedling. Our results showed that the soil properties, such as soil organic matter, total nitrogen, and cation exchangeable capacity were significantly higher in the mixed forest soil compared to the Larix kaempferi forest soil. Likewise, the growth characteristics of wild-simulated ginseng seedlings were significantly higher in mixed forestsd compare to the Larix kaempferi forest. Correlation analysis between tree species ratio, soil properties, and growth characteristics in the experimental plots determined that the soil properties and growth characteristics had significant positive correlation with the broad-leaved forest percentage. Growth characteristics of the wild-simulated ginseng seedlings were shown to have a significant positive correlation with organic matter, total nitrogen, and cation exchange capacities. This study has clearly demonstrated that the tree species ratio, and soil properties in Larix kaempferi and mixed forests were significantly correlated with the early growth of wild simulated ginseng seedlings. These results could help to improve the selection of suitable cultivation sites for wild-simulated ginseng.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.351-360
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• 2018

This study was conducted to analyze the responses of chlorophyll contents and growth of Pinus densiflora and Quercus variabilis seedlings on distance from the well and $CO_2$ flux after the artificial $CO_2$ release. From June 1 to 30, 2016, $CO_2$ gas was injected at the rate of $6L\;min^{-1}$ at the study site in Eumseong. Chlorophyll content was analyzed in the middle of July, 2016, and root collar diameter (RCD), height (H), and biomass were measured in May and December, 2016 after planting 2-year-old P. densiflora and 1-year-old Q. variabilis seedlings in May, 2015. The chlorophyll content of P. densiflora seedlings did not show a significant correlation with $CO_2$ flux, whereas the chlorophyll content of Q. variabilis seedlings showed a significant negative correlation with increasing $CO_2$ flux (P<0.05). The RCD and H growth rates of both species showed the significant difference in the distance from the well of the $CO_2$ anthropogenic release treatment. In particular, the RCD and H growth rate of P. densiflora seedlings and the RCD growth rate of Q. variabilis seedlings increased significantly as the seedlings were closer to the well, but the H growth rate of Q. variabilis seedlings decreased significantly. In addition, as the $CO_2$ concentration in the ground increases, ${\Delta}R/S$ ratio increases in both species, suggesting that the high $CO_2$ concentration in the soil promotes carbon distribution relative to the root part. The results of this study can be used as data necessary to monitor the $CO_2$ leakage and physiological and growth responses of both species to leakage of stored $CO_2$ in the future.

• Korean Journal of Environment and Ecology
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• v.36 no.3
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• pp.338-349
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• 2022

This study aims to investigate whether modular community planting, which entailed planting a variety of species of seedlings at high density, was more effective in restoring natural forests than the existing mature tree planting. We also investigated whether the planting density of the modular community planting facilitates growth or improves the tree layer coverage. We conducted outdoor experiments in which the samples were divided into a mature tree planting plot (control plot), where mature trees were planted at wide intervals, and a modular community planting (MCP) plot (treatment plot), where multiple seedlings were planted in high density. The MCP plot was further divided into the plot in which 3 seedlings were planted per m² and the plot of 1 seedling per m². We measured the specimens' survival rate, growth rate (tree height, crown width, and root collar diameter), and cover rate for 26 months from May 2019 and the predicted future tree height growth using the measured tree height. The survival rate and relative growth rate of the MCP were higher than those of the mature tree planting plot. The vertical coverage rate of the tree crown in the MCP exhibited complete coverage of the ground before 23 months, while the coverage rate of the mature tree planting decreased due to transplantation stress. The seedlings in the MCP, which were planted at high density, grew well and were predicted to grow higher than the mature trees in the large tree planting plot within 5 to 6.5 years after planting. It was due to multiple species, seedlings, high-density planting, and planting foundation improvements, such as soil enhancement and mulching. In other words, the seedlings planted in the MCP had a higher survival rate as their environmental adaptation after planting was better, and their early growth was also larger than the trees in the mature planting plot. The high-density mixed planting of various native species not only mitigated the inter-complementary environmental pressures but also facilitated growth by inducing competition between species. Moreover, the planting foundation improvement effectively increased the seedlings' viability and growth rate. A reduction in follow-up management costs is expected as the tree layer coverage sharply increases due to the higher planting density. In the MCP (3 seedlings per m² and 1 seedling per m²), the tree height growth was promoted with the higher planting density, and the crown width and root collar diameter tended to be larger with the lower planting density, but these differences were not statistically significant.

• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.39-44
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• 2007

The effect of inabenfide was investigated in rice seedlings subjected to salt stress in relation to changes in chlorophyll fluorescence(${\Delta}F/Fm'$), lipid peroxidation, salicylic acid(SA) content, and catalase(CAT) activity. A reduction in shoot growth of rice seedlings by 120 mM NaCl treatment was significantly alleviated by pretreatment with 30 ${\mu}M$ inabenfide. Sodium ion content was not affected by pretreatment with inabenfide, suggesting that alleviation was not due to a reduction in sodium ion uptake by the rice seedlings. At three days after NaCl treatment, the rice seedlings pretreated with inabenfide showed a higher ${\Delta}F/Fm'$(30%) and lower lipid peroxidation(28%) compared with the rice seedlings treated with NaCl alone. After NaCl treatment, CAT activity in the third leaf of rice seedlings decreased significantly but alleviated by pretreatment with inabenfide. Furthermore, pretreatment with inabenfide also reduced the level of SA which accumulated drastically in the third leaf of rice seedlings within a day after exposure to salt stress. These results suggest that inabenfide prevents SA accumulation in rice seedlings under salt stress which eventually induces the alleviation of salt stress damage.

• Journal of Plant Biology
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• v.32 no.2
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• pp.89-99
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• 1989

The effect of IAA on lysine decarboxylase(LDC)activity, diamine oxidase (DAO) activity and the polyamine level in seedlings of soybean were investigated. The seedlings of soybean were treated with IAA (10-8M, 10-6M, 10-4M) and LDC activity, DAO activity and polyamine levels of cotyledon, elongating hypocotyl, elongated hypocotyl and the root were measured after 4, 6, 8, 10 days. Increased concentration of IAA stimulated the LDC activity and increased the level of polyamine in the seedlings, which reducing the DAO activity and polyamine level was increased in the seedlings. The light also stimulated the IAA effect on polyamine level and DAO activity, and polyamine level was higher in the seedlings grown in the light than those in the dark. Cadaverine was the most abundant polyamine in the seedlings of soybean. The levels of diamines, cadaverine, putrescine were higher in the elongated hypocotyl and root than in the elongating hypocotyl, but the levels of spermidine and spermine were relatively higher in the cotyledon than in the other parts. Accumulation of diamines by high concentration of IAA is postulated to be a phenomenon of inhibition in seedlings growth.

• Korean Journal of Agricultural Science
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• v.44 no.2
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• pp.196-210
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• 2017

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia cepacia (C1) and Alcaligenes aquatilis (H6), was assessed in liquid medium and maize plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus (309.66 ?g/mL) into the medium, followed by single inoculation of B. cepacia (305.49 ?g/mL) and A. aquatilis strain (282.38 ?g/mL). Based on a plant growth promotion bioassay, co-inoculated maize seedlings showed significant increases in shoot height (75%), shoot fresh weight (93.10%), shoot dry weight (84.99%), root maximum length (55.95%), root fresh weight (66.66%), root dry weight (275%), and maximum leaf length (81.53%), compared to the uninoculated control. In a field experiment, co-inoculated maize seedlings showed significant increases in cob length (136.92%), number of grain/cob (46.68%), and grain weight (67.46%) over control. In addition, single inoculation of maize seedlings also showed improved result over control. However, there was no significant difference between single inoculation of either bacterial strains and co-inoculation of these two bacterial strains in terms of phosphate solubilization index, phosphorous release, pH of the media, and plant growth parameters. Thus, single inoculation and co-inoculation of these bacteria could be used as biofertilizer for improving maize growth and yield.