• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.735-742
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• 2006

The objective of this study was to elucidate the tolerance of woody plants to simulated acid rain in relation to mycorrhizal inoculation. Germinating seedlings of Robinia pseudoacacia were planted in 1I pots with autoclaved soil mixture of vermiculite, sand and nursery soil at 1:1:1 ratio. Each pot was inoculated with both crushed root nodules from a wild tree of the same species and commercial arbuscular mycorrhizal inoculum of Glomus intraradices at the time of planting the seedlings. Simulated acid rains at pH 2.6, 3.6, 4.6, and 5.6 were made by mixing sulfuric acid and nitric acid at 3: 1 ratio. Each pot received nutrient solution without N and P, and was also supplied with 180 ml of the one pH level of the acid rains once a week for 50 days. The plants were grown in the green house. At the end of experimental period, plants were harvested to determine contents of chlorophyll, mineral nutrients and net photosynthesis in the tissues, dry weight of the plants, and mycorrhizal infection in the roots. Mycorrhizal infection rate was significantly reduced only at pH 2.6, which meant vitality of G intraradices was inhibited at extremely low pH. Height growth, dry weight production, nodule production and chlorophyll content were increased by mycorrhizal infection in all the pH levels except pH 3.6. Particularly, mycorrhizal inoculation increased root nodule production by 85% in pH 5.6 and 45% in 4.6 treatments. But the stimulatory effect of mycorrhizal inoculation on nodule production was reduced at pH 3.6 and 2.6. Net photosynthesis was increased by mycorrhizal infection in all the pH levels. The phosphorus(P) content in the tissues was increased by 43% in average by mycorrhizal inoculation, which was statistically significant except in pH 2.6. It was concluded that mycorrhizal inoculation of Robinia pseudoacacia would enhance growth and resistance of the plants to acid rain by improving the photosynthesis, phosphorus nutrition, and more nodule production.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.193-200
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• 2017

BACKGROUND: Plant growth under smart greenhouse (that is plant factory system) conditions of an artificial light type is significantly depending on the artificial light sources such as a fluorescent lamps or Light-Emitting Diodes (LEDs) with specific spectral wavelengths regardless of the outside environmental changes. In this experiment, characteristics on the growth and compound synthesis of kale seedlings affected by light qualities and intensities provided by LEDs were mentioned. METHODS AND RESULTS: The kale seedlings which developed 3~4 true leaves were exposed by fluorescent lamps or LEDs lights of red (R), blue+white (BW), blue+red (BR) with 50 (L) or $100(H){\mu}mol/m^2/s^1$ photosynthetic photon flux (PPF) under hydroponic culture system of deep flow technique for 50 days. Shoot fresh weight increased under the RH, BWH, and BRH treatments with higher PPF. Shoot elongation of the seedlings decreased, and polyphenol synthesis promoted by the higher light intensity conditions. Sugar synthesis in the leaves was above 2 times greater under the RH treatment of monochromic red light quality with $100{\mu}mol/m^2/s^1\;PPF$ than $50{\mu}mol/m^2/s^1\;PPF$. CONCLUSION: The results show that the control of light quality and intensity in the smart greenhouse conditions with artificial lights significantly affects the growth and compound synthesis in the fresh kale leaves with higher culture efficiency compared to the conventional soil culture under greenhouse or field conditions. Researches on the optimum light intensities of the LEDs with special spectral wavelengths are necessary for maximum growth and metabolism in the seedlings.

• Journal of Bio-Environment Control
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• v.6 no.3
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• pp.151-158
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• 1997

Tomato (lycopersicon esculentum Mill.‘Sunroad’) seedlings grafted onto the four different rootstocks, ‘Anchor-T’, ‘Kagemushia’, ‘Joint’ and ‘Vulcan’, and fed with different amount of nitrogen were investigated for their susceptibility to the root rot Fusarium wilt (Fusarium oxysporum Schl. f. sp. lycopersici Snyder et Hansen, race J$_3$) disease, plant growth, and fruit quality. The flowering of the first flower cluster was promoted in grafted plants (GP) as compared to non-grafted (NG) ones. The plant height was increased by the grafting, and the growth and stem diameter were enhanced with increased nitrogen levels. Grafted plants were little affected by the Fusarium wilt disease except ‘Anchor-T’rootstock (64.7％ infection). The rate of malformed, underdeveloped, and gray-mold infected fruits were reduced in the grafted plants regardless of the rootstocks. Soluble solid content, sugars, ascorbic acids and organic acids did not show any difference between grafted and non grafted plants, but ascorbic acid tends to be reduced in the high nitrogen treatment. Content of N, Ca and Mg in leaves were greatly increased in the GP grown with high nitrogen level (30kg.㏊$^{-1}$ ).

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.8-16
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• 2012

The objective of this study was to identify bacterial antagonists of R. solani AG2-2 (IV) on zoysiagrass and to evaluate their antifungal activity in vitro and in vivo to select an antagonistic isolate. Antagonistic isolates that inhibit large patch disease caused by R. solani AG2-2 (IV) in zoysiagrass were selected from several soils, and their antagonistic activities were investigated in vitro and in vivo. Of 216 bacterial isolates, 67 inhibited several plant pathogenic fungi. The isolates that inhibited stem-segment colonization by R. solani AG2-2 (IV) in zoysiagrass were tested in a growth chamber. Eleven isolates were active as plant growth promoting isolates. Among them, five plant growth promoting isolates and their concentration dependent efficiency on zoysiagrass following inoculation with R. solani AG2-2 (IV) was evaluated. Isolate H33 was one of the potential antagonistic isolates, and it was further tested against various plant pathogens. H33 not only suppressed the disease caused by R. solani AG2-2 (IV) on zoysiagrass but also promoted leaf weight and leaf height of zoysiagrass under growth chamber and greenhouse conditions. The H33 isolate, which belongs to Streptomyces arenae, was identified through physiological, biochemical, and 16S rDNA studies. Further studies will investigate the cultural characterization of S. arenae H33 and isolation and identification of antifungal substance produced by S. arenae H33.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.396-404
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• 2010

Phenolic compounds, which are products of secondary metabolism, have been demonstrated to be widespread growth substances in plants. The objectives of this study were to identify the phenolic compounds in common ragweed (Ambrosia artemisiifolia var. elatior) by HPLC and to evaluate their effects on germination and seedling growth of three weed species. Under controlled conditions in Petri dishes at $25^{\circ}C$, $10^{-3}$ and $10^{-4}$ M solutions of phenolic compounds were evaluated in seed germination tests. Four phenolic compounds (caffeic acid, O-coumaric acid, ${\rho}$-coumaric acid and ferulic acid) in common ragweed plant were identified and their concentration was increased from the stage before flowering through full flowering stage. Treatment of O- and ${\rho}$-coumaric acids delayed the seed germination of Digitalia ciliaris, while the treatment of caffeic acid delayed the seed germination of Echinochloa crus-galli. In time to 50% germination ($T_{50}$), phenolic compounds at $10^{-4}$ M promoted in Cyperus microiria and E. crus-galli but the level of $10^{-3}$ M delayed the $T_{50}$ of those weeds. The O-coumaric acid inhibited seed germination and seedling growth of the tested weeds and especially it perfectly inhibited the root growth of E. crus-galli.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.11
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• pp.1024-1029
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• 2010

Use of polymeric soil amendments is an emerging way to reduce soil erosion, and improve crop productivity and soil quality. Objective of this study was to evaluate the effects of anionic polyacrylamide (PAM) and synthetic biopolymer on soil erosion, crop growth and soil quality. The aqueous solutions of PAM and biopolymer at 40 kg/ha were applied to loamy soil plots (3 m width by 18 m long) having a 20% slope during radish (Raphanus sativus) cultivation. Results showed that PAM and biopolymer treatments increased aggregate stability up to 11% compared to the untreated control. Treatments of PAM and biopolymer also increased leaf length of radish but there was no significant difference in crop yield. Soil loss was decreased by up to 41% using the polymeric soil amendments; however, no difference in runoff was found, compared to the untreated control. Soil loss was logarithmically increased against an increase in rainfall intensity ($R^2=0.85$). Our findings suggest that proper use of polymeric soil amendments would be beneficial to maintain soil quality and reduce soil erosion in sloping uplands.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.133-138
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• 2004

Growth of M.9 (Malus domestica Bark. cv) and M.26 (Malus domestica Bark. cv) of dwarf apple rootstock, cultured on MS agar medium in a vessel with ventilating stopper (VS) and then in vivo rooting and acclimatization under combined-treatment by some materials with IBA, were investigated. Concentration of $CO_2$ and ethylene in the vessel with VS was lower then in the vessel with non-VS. Change of temperature and humidity in the vessel with VS was repeated by light condition. Stomatal pares of tissue in the vessel with VS were immediately closed after plantlets were exposed to room humidity but those in the vessel with non-VS were opened after 20 minutes exposure to room humidity. Leaf area and chloroplast index of tissue in the vessel with VS was higher then in the vessel with non-VS. In vivo rooting ratio and acclimatization ratio of M.9 and M.26 was highest in 300mg/L IBA＋3％ sucrose dip-treatment among other combined- treatments.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.9-15
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• 2012

This study was conducted to increase grape quality by treating plant growth regulator (PGR) in 'Campbell Early' grape. Foliar application of gibberellic acid ($GA_3$) at $5mg{\cdot}L^{-1}$ on flower cluster of 'Campbell Early' grape at 3-5 unfolded leaf stage effectively increased columella length, berry weight, soluble solid contents and promoted skin color development. Foliar application of $20mg{\cdot}L^{-1}$ abscisic acid (ABA) mixed with $5mg{\cdot}L^{-1}$ of $GA_3$ on flower cluster of 'Campbell Early' grape at 3-4 unfolded leaf stage effectively increased skin anthocyanin contents without any detrimental effects on berry enlargement and columella growth. Foliar application of $2.5mg{\cdot}L^{-1}$ thidiazuron mixed with $5mg{\cdot}L^{-1}$ of $GA_3$ on flower cluster of 'Campbell Early' grape at 3-4 unfolded leaf stage effectively increased fruit quality indices such as higher soluble solid contents and less titratable acidity.

• Journal of Plant Biotechnology
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• v.34 no.4
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• pp.331-338
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• 2007

One-node stem pieces ca. 1 cm in length containing a axillary bud and a fully expanded leaf were obtained from it in vitro plants of potato (Solanum tuberosum L.). Leaves were removed and the nodes were cultured on the MS medium to investigate the effects of temperature, day length, sucrose, and CCC in microtuber formation and development. The fresh weight of microtubers after 80 days increased significantly at 8% sucrose and $20^{\circ}C$ compared with $28^{\circ}C$. The tuberization and development were reduced at $28^{\circ}C$ except short-day treatment of 8 hours at 8% sucrose. The fresh weight and diameter were increased on the culture medium added CCC 500 mg/L. The potato tuberization was promoted under short daylength, and it showed great effect by treatment with the CCC. Though the tuberization was promoted at low temperature of $20^{\circ}C$ in a histologic change of an axillary bud part cell of a potato, the cells were able to observe the swelling growth. Swelling growth of tissue was stimulated in the darkness and was more remarkable by addition of CCC. In particular, in the visual ratio of cell division for each position in the tissue, the cortex part showed larger ratio of cell expansion than that of the pith part. The effect of CCC was identified at 8% sucrose in the darkness. The effect of CCC was not showed in sucrose 3% under long daylength of 16 hours. As a result, the fact of a substance with AGPase important for starch composition was certified by the result with the inclose of AGPase activity on high concentration of sucrose, CCC, and dark treatment by which tuber formation and development are promoted.

• Journal of Korean Society of Forest Science
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• v.37 no.1
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• pp.35-40
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• 1978

The uptake ratio of supplying $P^{32}$ labelled double superphosphate and the hastening efficiency of the uptake by addition of magnesium sulfate to the fertilizer were studied on the ${\times}Populus $ albaglandulosa planted with 0/1 cutting in 1975. The results are summerized as follows. 1. Average 13% of supplying double superphosphate was absorbed into ${\times}Populus$ albaglandulosa planted on the reddish heavy clay soil in Institute of Forest Genetics. 2. The accumulation of absorbed magnesium was more amount in leaf than in stem. 3. The uptake ratio of supplying double superphosphate was able to increase up to 16%~33% by the addition of magnesium sulfate to the fertilizer. 4. It might be possible to increase the tree growth following the acceleration of photosynthesis due to the increasing amount of magnesium known to be a component of chlorophyll in leaf as well as to hasten the efficiency of uptake of phosphorus by the addition of magnesium to double superphosphate.