• Research in Plant Disease
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• v.21 no.4
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• pp.255-260
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• 2015

We investigated influence of three commercial antibiotics viz., oxolinic acid, streptomycin, and validamycin A, on biocontrol and plant growth promoting activities of Bacillus vallismortis EXTN-1 and BS07M in Chinese cabbage. Plants were pre-drenched with these strains followed by antibiotics application at recommended and ten-fold diluted concentration to test the effect on biocontrol ability against soft rot caused by Pectobacterium carotovorum SCC1. The viability of the two biocontrol strains and bacterial pathogen SCC1 was significantly reduced by oxolinic acid and streptomycin in vitro assay, but not by validamycin A. In plant trials, strains EXTN-1 and BS07M controlled soft rot in Chinese cabbage, and there was a significant difference in disease severity when the antibiotics were applied to the plants drenched with the two biocontrol agents. Additional foliar applications of oxolinic acid and streptomycin reduced the disease irrespective of pre-drench treatment of the PGPRs. However, when the plants were pre-drenched with EXTN-1 followed by spray of validamycin A at recommended concentration, soft rot significantly reduced compared to untreated control. Similarly, strains EXTN-1 and BS07M significantly enhanced plant growth, but it did not show synergistic effect with additional spray of antibiotics. Populations of the EXTN-1 or BS07M in the rhizosphere of plants sprayed with antibiotics were significantly affected as compared to control. Taken together, our results suggest that the three antibiotics used for soft rot control in Chinese cabbage could affect bacterial mediated biocontrol and plant growth promoting activities. Therefore, combined treatment of the PGPRs and the commercial antibiotics should be carefully applied to sustain environmental friendly disease management.

• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.64-71
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• 2002

Plant growth promoting activity of quinolinone metabolites, 2-(2-hepteny)-3-methyl-4-quinolinone (1), 2-heptyl-3-methyl-4-quinolinone, and 2-nonyl-3-methyl-4-quinolinone, produced by Pseudomonas cepacia and ethyl 2-methyl-3-alkyl-4-quinolinone carboxylates chemically synthesized were tested by using seed-germination assay, growth increments in plant height after foliar applications. Plant height increment, fresh weight, and the number of fruits were measured after seed-soaking and drench treatment. Compound 1 among the natural products showed a consistent growth promoting effect in seed-germination and plant height after a foliar application. After a seed-soaking and drench treatment, compound 1 and synthetic ethyl 2-methyl-4-quinolinone-3-carboxylate (5) showed a significant enhancement in fresh weight and the number of fruits after harvest. Compound 1 and 5 increased the number of fruits per plant by 44% and 84% over the control, respectively.

• Korean Journal of Plant Resources
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• v.18 no.3
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• pp.367-373
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• 2005

The purposes of this dissertation were to examine relativity between growth characteristics factors and develop the model of growth characteristics. In the result of statistical summaries of the factors in growth characteristic, the highest level of correlation was in plant height, plant width, petiole and chlorophyll in the case of Artemisia iwayomogi; leaf length, in the case of A. stolonifera;, leaf width, of A. princeps var. orientalis;, diameter, of A. feddei;, leaf thickness, of A. iwayomogi, A. princeps var. orientalis, A. montana, A. stolonifera, A. sylnatica; leaf length and leaf width of the other species. In the case of correlation analysis, leaf width and diameter were most correlative in A. capillaris;, plant height and plant width, in A. montana; plant height and leaf width, in A. stolonifera; leaf length and leaf width, in other species. The results of model analysis of growth characteristics were as follows. A. capillaris proved to be about $79.4\%$ effective ; A. princeps var. orientalis, about $91.7\%$ ; A. montana, about $70.3\%$ ; A. iwayomogi, about $49.0\%$ ; A. stolonifera, about $72.5\%$; A. sylnatica, about $75.0\%$;, A. feddei about $60.4\%$ ; A. rubripes about $54.0\%$.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.190-190
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• 2017

Chemical fertilizers have been used to increase crop production and contributed to escaping food shortages. However, excessive use of chemical fertilizers over a long period caused many problems such as environmental pollution and the hampered production potential of the land. Thus, it is necessary to develop eco-friendly bio-fertilizers that can replace the use of chemical fertilizers. Here, we tested the effect of some nitrogen-fixing microorganims on the plant growth promotion. Seventy free-living nitrogen fixing microorganisms were isolated from rhizosphere of crop cultivation fields, streamside soils and sludge in Ansung, Korea. Of them, three strains (NF2-4-1, Yeast; EMM409, Mesorhizobium; Gsoil662, Burkholderia) were selected to be most efficient in the capacity of N-fixing nitrogen based on colony forming cell assay in N-free media. To investigate the ability to promote plant growth, these strains were inoculated into the soil and cabbage were grown for 4 weeks in the grown chamber. Fresh weight, dry weight, and leaf area were measured from 4-week-old plants. Phenotypic analysis revealed that the growth of the plants inoculated with NF2-4-1 and EMM409 strains were significantly promoted compared to the mock-treated control plants, while Gsoil662-inoculated plants did not show statically significant promotion. These results indicate that these nitrogen-fixing microorganims can be used to develop plant growth promoting bio-fertilizers. Further analysis on nitrogen fixing level in soil by these strains will be tested.

• Korean Journal of Plant Resources
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• v.32 no.3
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• pp.228-236
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• 2019

This study is conducted to investigate the effects of growth characteristics (GC) and DPPH radical scavenging activity (DRSA) of the heading lettuce 'Fidel' depending on four concentrations of activated mineral groups (AMG: 1.6% active minerals and 0.03% CaO) added to basic nutrient solutions (diluted by 0, 0.05, 0.1, and 0.2%) and on four different light-emitting diodes (LED; B:R:W ratio = 0:1:12, 0:1:9, 0:5:5, and 2:3:5). Both 0.1 and 0.2% AMG showed better GC of lettuce in plant width, plant length, leaf width, leaf length, and the number of leaves than those of other AMG, while leaf thickness and chlorophyll value did not show significant difference among all AMG. Moreover, 0.1 and 0.2% AMG showed heavier shoot fresh weights than those of other AMG. As for the combinations of AMG and LED, B0:R5:W5 showed the best lettuce GC regardless of AMG compared to other AMG and LED combinations. As shown in the above results of LED, although there was a difference in lettuce growth by LED, the differences of lettuce growth by AMG were statistically significant. The DRSA was the highest at 82.8% in B2:R3:W5, followed by B0:R5:W5 at 77.8%. LED showed differences but AMG did not affect DRSA. Therefore, the optimal conditions in plant factory for GC and DRSA of the lettuce were 0.1% AMG and B0:R5:W5.

• Journal of Plant Biotechnology
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• v.4 no.4
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• pp.151-154
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• 2002

Conditions for lily pollen growth in vitro and transformation were optimized. Active pollen tube development was achieved effectively in a medium containing 7% sucrose with pH adjusted to 5.7 at the temperature of 27$^{\circ}C$ for about 16-24 hours. Pollen growth was little impaired by the presence of kanamycin at concentration up to 100 mg/L. Pollen rains near the beginning of germination stage were more reliable for Agrobacterium-mediated GUS DNA transformation via vacuum infiltration lasted for 20-40 minutes. GUS DNA integration and its expression in fully developed pollen tubes could be confirmed by Southern blot hybridization, RT-PCR and histochemical staining.

• Korean Journal of Plant Resources
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• v.22 no.3
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• pp.215-219
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• 2009

In these experiments Gamiojeoksan remnant components were analyzed to recycle this medicinal herb remnant fertilizers. The basic growth of Korean mint by application of Gamiojeoksan remnants were higher than control. As the amount of fertilizers were increased, plant height, stem diameter, number of leaves and number of branches were increased. The growth and yield were the highest in the treatment of 30 g/pot. Weight of whole plant of Korean mint has a tendency to be heavy in application of herbs remnant than that of control.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.15-21
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• 1998

This study was carried out to determine the effects of plant growth regulators on cell culture and organogenesis from Sicyos angulatus L. using explants of leaves, stems and cotyledons. Optimal callus induction for S. angulatus was obtained on MS medium with 0.1mg/$\ell$ BA and 2.0mg/$\ell$ 2,4 -D from cotyledons, 0.1mg/$\ell$ BA and 5.0mg/$\ell$ NAA from leaves explants, Optimal media for subculture and growth of S. angulatus callus were 1/2 MS medium with 0.1mg/$\ell$ BA and 1.0mg/$\ell$ 2,4 -D for solid culture, and 0.1mg/$\ell$ 2,4-D for suspension culture. Many adventitious roots with some shoots were formed were formed from leaf and cotyledon explants of S. angulatus during callus induction with optimal combinations of plants growth regulators.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.269-272
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• 1998

Characteristics of seed and plant growth of the nine local collections of the medicinal plant, Agastache rugosa were evaluated. Seed size of the collection from Garyungsan was larger than the others. Seeds of Damyang collection were the smallest in size. Seeds of the collections were mostly oval shaped. There were no differences between brown and black seed coat color groups in seed width, ratio of seed length to seed width and 1,000 seed weight. Stem lengths of Garyungsan and Bongpyung collections were 99.9 and 95.6 cm, respectively, and were longer than Damyang and Jindo collections. Garyungsan collection had long leaf shape. Leaf size was the smallest for Damyang collection, but was the largest for Bongpyung collection. Inflorescence length of Mokpo collection (15.6 cm) was longer than the average over all collections (12.3 cm). Damyang collection was the shortest (10.1 cm) in inflorescence. Top dry weight of each collection from Soonchun, Bongpyung, Mokpo, Jindo, and Gurye was greater than the average over all collections (20.38 g/plant). Jinju and Damyang collections had less top dry matter than others. There was no difference in the growth traits examined between brown and black seed coat groups. The brown seed group was greater in leaf weight than the black seed group. However, these two groups were not different in stem and inflorescence weight. Collections of A. rugosa from Bongpyung, Soonchun, and Mokpo were promising for commercial cultivation because of their great top dry weight, especially in leaf and inflorescence.

• Journal of Korea Soil Environment Society
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• v.3 no.3
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• pp.63-74
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• 1998

In the study, the feasibility of deposit soil in river and stream bed as a subsitute for conventional plant soil was investigated through the analysis of soil characteristics and germination/growth rate for 75 days. Proper mixtures among sediments from various places were compared to optimize the germination and growth rate of plant in the ratio of 2 : 1 and 3 : 1 (sand : deposit). From the results, it could be concluded that the sediment mixed 3 : 1 showed most favorable germination and growth conditions for pansy and the sediment containing enough amount of silt and clay components showed most favorable conditions for marigold. Consequently, the feasibility of sediments as a substitutional plant soil was evaluated to be high, once the sediments were properly mixed for each specific plant.