• Horticultural Science & Technology
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• v.32 no.3
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• pp.318-329
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• 2014

In order to gain insight into the physiological responses of plants to high temperature stress, the effects of temperature on Chinese cabbage (Brassica campestris subsp. napus var. pekinensis cv. Detong) were investigated through analyses of photosynthesis and chlorophyll fluorescence under 3 different temperatures in the temperature gradient tunnel. Growth (leaf length and number of leaves) during the rosette stage was greater at ambient $+4^{\circ}C$ and ambient $+7^{\circ}C$ temperatures than at ambient temperature. Photosynthetic $CO_2$ fixation rates of Chinese cabbage grown under the different temperatures did not differ significantly. However, dark respiration rate was significantly higher in the cabbage that developed under ambient temperature relative to elevated temperature. Furthermore, elevated growth temperature increased transpiration rate and stomatal conductance resulting in an overall decrease of water use efficiency. The chlorophyll a fluorescence transient was also considerably affected by high temperature stress; the fluorescence yield $F_J$, $F_I$, and $F_P$ decreased considerably at ambient $+4^{\circ}C$ and ambient $+7^{\circ}C$ temperatures, with induction of $F_K$ and decrease of $F_V/F_O$. The values of RC/CS, ABS/CS, TRo/CS, and ETo/CS decreased considerably, while DIo/CS increased with increased growth temperature. The symptoms of soft-rot disease were observed in the inner part of the cabbage heads after 7, 9, and/or 10 weeks of cultivation at ambient $+4^{\circ}C$ and ambient $+7^{\circ}C$ temperatures, but not in the cabbage heads growing at ambient temperature. These results show that Chinese cabbage could be negatively affected by high temperature under a future climate change scenario. Therefore, to maintain the high productivity and quality of Chinese cabbage, it may be necessary to develop new high temperature tolerant cultivars or to markedly improve cropping systems. In addition, it would be possible to use the non-invasive fluorescence parameters $F_O$, $F_V/F_M$, and $F_V/F_O$, as well as $F_K$, $M_O$, $S_M$, RC/CS, ETo/CS, $PI_{abs}$, and $SFI_{abs}$ (which were selected in this study), to quantitatively determine the physiological status of plants in response to high temperature stresses.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.217-223
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• 2011

This study was conducted to examine the effect of several pretreatments and holding solutions on the vase life and quality of cut Polygonatum odoratum var. pluriflorum for. variegatum stems native to Korea. Postharvest foliar spray of 200 $mg{\cdot}L^{-1}$ $GA_3$ or 200 $mg{\cdot}L^{-1}$ BA + 200 $mg{\cdot}L^{-1}$ $GA_3$ markedly extended the vase life of cut stems of Polygonatum odoratum var. pluriflorum for. variegatum. These treatments maintained high chlorophyll contents as compared with the control (distilled water) during senescence of cut stems. Postharvest pretreatment (dipping) with 100 $mg{\cdot}L^{-1}$ $GA_3$ or 3% sucrose + 200 $mg{\cdot}L^{-1}$ 8-hydroxyquinoline sulfate (HQS) + 100 $mg{\cdot}L^{-1}$ $GA_3$ for 16 hours extended vase life of cut stems 2.5 times as long as nontreated control. Holding solution of 2% sucrose + 200 $mg{\cdot}L^{-1}$ HQS + 100 $mg{\cdot}L^{-1}$ $GA_3$ significantly extended vase life by 3.5 times and increased fresh weight as compared with control. $GA_3$ were very effective on preventing leaf yellowing of cut Polygonatum odoratum var. pluriflorum for. variegatum stems. Postharvest foliar spray of 200 $mg{\cdot}L^{-1}$ $GA_3$ or holding solution of 2% sucrose + 200 $mg{\cdot}L^{-1}$ HQS + 100 $mg{\cdot}L^{-1}$ $GA_3$ markedly extended vase life and improved quality of cut stems of Polygonatum odoratum var. pluriflorum for. variegatum.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.149-160
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• 2008

This study was carried out to examine the growth performance of 10 cultivars of creeping bentgrass under salt injury in Seo-san reclaimed area. Turfgrass performance studies included 10 creeping bentgrass cultivars (T-1, L-93, Penn A1, Pennlinks II, Seaside II, Declaration, Penn A4, Crenshaw, Dominant, and Penncross). Ten creeping bentgrass cultivars were grown on a USGA recommended research green. Plots were seeded on May 31, 2006 at the rate of $7\;g{\cdot}m^{-1}$. Electric conductivities of irrigation water (ECw) and soil (ECe) were ranged from 0.28 to $3.3\;d\;S{\cdot}m^{-1}$ and from 0.25 to $3.5\;d\;S{\cdot}m^{-1}$ respectively. Leaf color, turf quality, coverage rate, and growth rate were checked under the salty condition in reclaimed land for 2 year. Creeping bentgrass cultivars of T-1, Penn links, and Crenshaw presented dark green color and Penn A1, Declaration showed lighter green color. Penn A1, Penn A4 and L-93 exhibited the highest overall turfgrass quality. Average visual coverage was 75.3% after eleven weeks after seeding. Dominant, L-93, and Penn A1 resulted in higher visual coverage compared to the other cultivars. There was no difference in density among cultivars at 1 year after establishment. However, Declaration, Penn A1, T-1, and L-93 showed higher density compared to the other cultivars at 2 years after seeding. Creeping bentgrass showed different quality, density and color in salty soil (ECe: $0.25-3.5\;d\;S{\cdot}m^{-1}$) and from application of salty irrigation water (ECw: $0.28-3.3\;d\;S{\cdot}m^{-1}$) conditions. These results will be useful where selecting green cultivars for the golf courses in reclaimed land area.

• Food Science and Preservation
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• v.21 no.1
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• pp.129-139
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• 2014

This study was conducted in order to investigate the optimal fermentation periods of the Smilax china L. leaves as a fermented tea via Aspergillus oryzae for 0 (non-fermented), and 10, 20, and 30 days (NF, F10, F20, F30). It was also observed for its quality characteristics. In the color and spectrum (400~700nm) of 1% tea water extract, NF was light yellow, whereas fermented tea (F10~F30) was light red color, and the F10 among F10~F30 has the clearest color and spectrum. Furthermore, acceptabilities of aroma and brightness were insignificantly different between NF and F10~30, while the mouth feel and overall acceptabilities were insignificantly distinct among all of the fermented teas. Therefore, these results suggest that the appropriate fermentation period for tea fermentation is 10 days. On the other hand, the total polyphenol and flavonoid content in the NF was the highest among all of the fermented teas. In the antioxidant parameters, EDA (electron donating ability), FRAP (ferric reducing antioxidant power), and LPOIA (lipid peroxidation inhibitory activity) in the NF were the highest among all fermented teas. Meanwhile, the XOI (xanthine oxidase inhibitory activity) was low, as well as insignificantly different from NF and F10~F30, whereas the AOI (aldehyde oxidase inhibitory activity) was markedly higher (38.09~41.70%) by the hot water tea extract (with or without fermentation), particularly the AOI that has increased via fermentation. In conclusion, the overall antioxidant activity tended to be reduced by fermentation; however, the EDA, FRAP and LPOIA in the fermented tea for 10 days was higher than the activities during 20~30 days of fermentation. There was a similar result in the color and acceptability of fermented tea for 10 days, which was remarkably better than those of 20-30 days. Therefore, fermented tea from the leaves of Smilax china L. could be expected to be used as a functional tea without the loss of inhibitory activity of both the XO and AO via fermentation.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.25-25
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• 2014

Three species of Fusarium, F. fujikuroi, F. verticillioides and F. proliferatum, are known to be associated with bakanae disease of rice [1, 2]. F. fujikuroi infects rice flowers and survive in endosperm and embryo of the seeds. Infected seed is an important source of primary inoculum of pathogens [3]. Seeds of rice (Oryza sativa cv. Boramchan) collected from bakanae-infected field were found to be 96% infected with Fusarium sp., 52% with F. fujikuroi, 42% with F. verticillioides, and 12% with F. proliferatum as determined by incubation method and species-specific PCR assays. F. fujikuroi was detected at lemma/palea, endosperm and embryo whereas F. verticillioides and F. proliferatum were recovered only from lemma/palea by means of component plating test. Seed disinfection methods have been developed to control bakanae disease and prochloraz has been most widely used for rice seeds. Two chemicals formulated with prochloraz (PC 1) and prochloraz + hexaconazole (PC 2) that inhibit biosynthesis of ergosterol strongly reduced the incidence of Fusarium spp. on selective media to 4.7% and 2.0%, respectively. Disease symptoms of rice seedlings in nursery soil were alleviated by chemical treatment; seedlings with elongated leaves or wide angle between leaf and stem were strikingly reduced from 15.6 to 3.2% (PC 1) and 0 (PC 2), stem rots were reduced from 56.9 to 26.2% (PC 1) and 32.1% (PC 2), and normal seedling increased from 0.4 to 13.3% (PC 2). Prochloraz has some disadvantages and risks such as the occurrence of tolerant pathogens [4] and effects on the sterol synthesis in animals and humans [5]. For these reasons, it is necessary to develop new disinfection method that do not induce fungal tolerance and are safe to humans and animals. Chlorine dioxide ($ClO_2$), that is less toxic, produces no harmful byproducts, and has high oxidizing power, has been reported to be effective at disinfection of several phytopathogenic fungi including Colletotrichum spp. and Alternaria spp. [6]. Gaseous $ClO_2$ applied to rice seeds at a concentration of 20 ppm strongly suppressed mycelial growth of Fusarium fujikuroi, F. verticillioides and F. proliferatum. The incidence of Fusarium spp. in dry seed with 8.7% seed moisture content (SMC) tended to decrease as the concentration of $ClO_2$ increased from 20 to 40 ppm. Applying 40 ppm $ClO_2$ at 90% relative humidity, incidence was reduced to 5.3% and resulted in significant reduction of disease symptoms on MS media. In nursery soil, stem rot was reduced from 56.9 to 15.4% and the number of normal seedlings increased from 0.4 to 25.5%. With water-soaked seeds (33.1% SMC) holding moisture in the endosperm and embryo, the effectiveness of disinfection using $ClO_2$ increased, even when treated with only 20 ppm for four hours. This suggests that moisture was a key element for action of $ClO_2$. Removal of the palea and lemma from seeds significantly decreased the incidence of Fusarium spp. to 3.0%. Seed germination appeared to decrease slightly by water-soaking at $30^{\circ}C$ because of increased SMC and by physical damage of embryos from hulling. These results indicate that the use of gaseous $ClO_2$ was effective as a means to disinfect rice seeds infected with Fusarium spp. and that moisture around the pathogens in the seed was an important factor for the action of $ClO_2$. Further investigations should be conducted to ascertain the best conditions for complete disinfection of Fusarium spp. that infect deep site of rice seeds.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.83-89
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• 2010

We investigated the growth of cucumber plants, the uptake and use of mineral nutrients, such as $NO_3$-N, $NH_4$-N, $K^+$, $Ca^{+}^{+}$, $Mg^{+}^{+}$ and $Na^+$, absorbed from media solution, and the synthesis and distribution of soluble sugars under nutrient-deficient condition. Difference in plant growth revealed after 20 days of treatment. Nitrate uptake in nutrient-deficient condition was significantly reduced compared with nutrient-normal treatment, and its distribution was primarily in petioles, stem, roots and less in leaves. In contrast, ammonium content was markedly predominated in fast growing organs, and it was significantly different in growing leaves, expanded leaves, and roots under similar growth conditions. $K^+$, lack by deficient nutrient condition, was found in growing leaves. The $Ca^{+}^{+}$ content did not show significant difference between treatments and a substantial portion of $Ca^{+}^{+}$ remained in petioles. The $Mg^{+}^{+}$ content was significantly higher in the leaves of nutrient-normal condition compared with nutrient-deficient condition while significantly lower in stem and roots. The behavior of $Na^+$ in plant was similar to $K^+$ although its content was relatively little. The highest $CO_2$ assimilation was observed in fully expanded leaves of nutrient-normal condition, which was 1.7 times higher compared with nutrient-deficient condition. The instantaneous water use efficiency (A/E) and the A/gsratio, which is an index of leaf intrinsic water use efficiency for individual leaves, was 1.2 and 1.1 times higher, respectively. The total soluble sugar (TSS) contents were highest in leaves followed by petioles, stems and roots, and in younger leaves. The growing leaves contained about 7,200 mg $kg^{-1}$ of TSS in nutrient-normal condition whereas the TSS contents in nutrient-deficient condition were not significantly different between leaves. The $Mg^{+}^{+}$ and $NH_4$- N were positively correlated with the TSS whereas $NO_3$ - N was negatively correlated.

• Journal of Wetlands Research
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• v.1 no.1
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• pp.29-44
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• 1999

Vegetation structure and distribution of the vascular hydrophytes and hygrophytes, and the growth pattern, standing crop and amounts of nutrient uptake by Salix species were investigated in the upper stream wetlands of the Namgang-Dam, Chinju-city, Gyeongsangnam-do, Korea from April to November in 1997. The flora was composed of 43 hydrophytes and 241 hygrophytes, or total 284 vascular plants. The life forms of the hydrophytes were classified as 27 kinds of emergent plants, 4 floating-leaved plants, 3 free-floating plants, and 9 submersed plants. In the herb layer, the dominant species was Persicaria hyciropiper, and the ranges of the species diversity indices (H'), equitabilities, (J') and community similarity indices (CCs) were 1.59~1.89, 0.87~0.96, and 0.35~0.83, respectively. In the shrub and subtree layers, 17 kinds of Salix species were supposed to the pioneer plants at the early stage of the succession. The number of branches per main stem of Salix species was 5.0. The DBH class-frequency histograms of Salix species were the reverse J type, and the natural regeneration of the Salix community was expected. Basal area of Salix species per square meter was $24.87cm^2$. Volume of Salix species per square meter was $12,008cm^3$ and total phytomass of the Salix species was estimated as 12,894 ton. Biomass distribution of Salix species in the stem, the branch and twig, and the leaf was 64.1%, 28.1%, and 7.8%, respectively. The amounts of nitrogen and phosphorus absorbed by Salix species were 68,022 and 19,823 kg. It was recommended that application and conservation of the wetland and other counterplans are indispensable to reduce the adverse effects of water pollution and to preserve the wetland ecosystem.

• Korean Journal of Plant Resources
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• v.25 no.1
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• pp.156-168
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• 2012

Chrysanthemum is a cut flower species that normally lasts for 1 to 2 weeks, in some cases 3-4 weeks. This has been attributed to low ethylene production during senescence. Reduction in cut flower quality has been attributed to the formation of air embolisms that partially or completely blocks the water transport from the vase solution to the rest of the cut flower stem, increasing hydraulic resistance which may cause severe water stress, yellowing, wilting of leaf, and chlorophyll degradation. Standard type chrysanthemum can be harvested when buds were still tightly closed and then fully opened with the simple bud-opening solution. Standard type chrysanthemum can also be harvested when the minimum size of the inflorescence is about 5-6 cm bud which opened into the first flower full-sized flower. While spray varieties can be harvested when 2-4 most mature flowers have opened (40% opening). Cut flowers are sorted by stem length, weight, condition, and so on. Standard chrysanthemum is 80 cm length for standard type and 70cm for spray type. Pre-treatment with a STS, plant regulator such as GA, BA, 1-MCP, chrysal, germicide, and sucrose, significantly improved the vase life and quality of cut flowers. It is well established that vase solutions containing sugar can improve the vase life of cut chrysanthemum. Chrysanthemum is normally packed in standard horizontal fiberboard boxes. Chrysanthemum should normally be stored at $5{\sim}7^{\circ}C$. Precooling resulted in reduction in respiration, decomposition, and transpiration activities as well as decoloration retardation. There was significant difference between "wet" storage in 3 weeks and "dry" storage in 2 weeks. In separate pulsing solution trials, various germicides were tested, as well as PGRs to maintain the green color of leaves and turgidity. Prolonging vase life was attained with the application of optimal solution such as HQS, $AgNO_3$, GA, BA and sucrose. This also retarded senescence in leaves of cut flower stems. Fresh cut chrysanthemum can be transported using a refrigerated van with $5{\sim}7^{\circ}C$. Increasing consumption and usage of cut chrysanthemum of various cultivars would require efficient transport system, and effective information exchange among producer, wholesaler, and consumer.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.471-477
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• 2004

Oldenlandia diffusa is a Chinese medicinal herb with antitumor activity capable of suppressing the growth of some cancer cell lines. Oleanolic acid and ursolic acid are triterpenoid compounds that exist in Oldenlandia diffusa. Recently, these have been noted for anti-inflammatory, anti-cancer, and hepato-protective effects. Application of both plant growth regulators, 2,4-D and kinetin, was found to be essential for the initiation of callus and suspension cells. Leaf blades of Oldenlandia diffusa was transformed into callus on Schenk and Hildebrandt medium supplemented with 0.5 mg/L 2,4-D and 0.1 mg/L kinetin, while optimum initiation condition for suspension cells of Oldenlandia diffusa was determined to be 0.75 mg/L 2,4-D and 0.1 mg/L kinetin. Chromatographic separation of oleanolic acid from its derivatives was achieved using Rexchrom S5-100-ODS column. Analytical conditions for oleanolic acid were determined as follows: flow rate at 1.0 mL/min, UV length at 200 nm and mobile phase of $80\%$ acetonitrile and $20\%$ water. Production of secondary metabolites was found to be increased by the treatment with elicitors or signal transducers. The maximum production of oleanolic acid was 99.6 mg/L in cultures with 0.5 mM salicylic acid. It is 1.74 times higher than that of control.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.202-208
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• 1985

The significant chemical constituents estimating the quality of green tea were compared and analyzed in the tea shoots of native Korean tea plants. The tea shoots of different varieties among native tea plants were plucked in Waun-ri, Yongjang-ri, others in eight tea-growing places, and Yabukita, for the comparison, which is excellent Japanese variety. The contents of Yongjang-ri tea shoots were 0.55% lower in total nitrogen, 41.44mg% lower in vitamin C and 0.56% higher in tannin than the average of the other eight places. The contents of ash, caffeine and water extract showed no difference between the tea shoots. Tea shoots of Waunri had similar compositions compared with those of Yabukita and other eight places in the chemical constituents. It is considered that the tea loaves in Yongjang-ri would be different variety comparing with other eight places in the view of characters and constituents. And it is thought that tea loaves in Waun-ri would be the large leaf variety of same genealogy because tea loaves in Waun-ri was different from the other eight places in characters, but was similar to in constituents.