• Research in Plant Disease
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• v.11 no.1
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• pp.80-84
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• 2005

Bacterial canker of sweet cherry (Prunus avium L.) was observed in farmers\' orchards in Goesan, Chungbuk in 2003. Typical canker symptoms occurred on the branches or twigs of sweet cherry in early spring and bacterial exudates oozed out of the cracked barks of diseased trees. Watersoaked brown symptoms appeared on the leaves and severe infection caused thorough defoliation on the branches or twigs of sweet cherry. When severely infected branches or twigs were cut, irregular and rusty-colored symptoms in sapwood and heartwood were clearly found, indicating that they can serve as specific symptoms of bacterial canker of sweet cherry. The causal bacterium responsible for the symptoms was isolated purely from the infected sapwood of sweet cherry. Based on its morphological, physiological and biochemical characteristics, the causal bacterium was identified as Pseudomonas syringae pv. morsprunorum. The bacterium was pathogenic on sweet cherry and Japanese apricot, but not on peach, cherry, and kiwifruit. It is proposed that the disease be named as bacterial canker of sweet cherry.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.55-63
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• 2001

Populus euramericana and Betula platyphylla var. japonica have been identified as possible species for use for phytoremediation of landfills. To identify the effects of waste leachate on growth and physiological characteristics in Populus euramericana and Betula platyphylla var. japonica, four different treatments were applied to seedlings for 3 months: leachate solution(100% leachate), 50% dilution(50% leachate: 50% water, v/v), 75% dilution(25% leachate: 75% water, v/v) and control(tab water) were applied to these two species. Treatment with waste leachate significantly stimulated both Populus euramericana and Betula platyphylla var. japonica height, diameter at root collar and biomass production relative to the water control. Chlorophyll contents, photosynthesis and transpiration of leachate irrigated-trees were significantly higher than those of water control. These results suggested that these two species could be suitable species for phytoremediation in landfills because these species showed good growth performance and were capable of taking up waste leachate.

• The Korean Journal of Food And Nutrition
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• v.36 no.3
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• pp.185-192
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• 2023

This study analyzed the chemical characteristics and physiological activity of five kinds of fresh vegetables produced in trees in early spring and tried to use them as basic data for wild vegetable producers and processed food manufacturers using wild vegetables. The crude protein, minerals, ascorbic acid, folate, total phenol, total flavonoid, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and ACE (angiotensin converting enzyme) inhibitory activity were determined. Five spring wild vegetables contain high protein and phosphorus, indicating that they are useful food ingredients as sources of protein and phosphorus. Vitamin C content was high in R. venicifera and C. sinensis shoots, and in particular, R. venicifera and A. cortex shoots have high folic acid (folate) contents of 1,903.91 ug% and 1,525.35 ug%, respectively, which is considered a good food for folic acid intake in spring. The total phenol content was between 0.52% and 1.27%, and it was the highest in C. sinensis of 1.27%, followed by the order of R. venicifera, A.cortex, K.pictus, and A. elata, which tended to be consistent with the total flavonoid content. As for DPPH radical scavenging ability, C. sinensis (55.93%) showed the highest activity, and ACE inhibitory activity showed the highest activity in A. cortex (88.04%).

• The Korean Journal of Quaternary Research
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• v.17 no.2
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• pp.123-128
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• 2003

This study was conducted to examine the water use efficiency (WUE) in five species of one-year-old seedlings grown in a field nursery in Mongolia. Larix sibirica and Pinus sylvestris are the most dominant coniferous species while Ulmus pumila is an important deciduous species known well-adapted in harsh conditions such as in semi-arid forests and Gobi desert regions. Caragana arborescens (Siberian pea shrub) and Hippophae rhamnoides are N-fixing shrubs in Mongolia. Thirty one-year-old seedlings were sampled from each of the five species (a total of 150 samples) and measured for net photosynthetic rate (Pn) and transpiration rate (E). The Pn and E were used to calculate and compare the WUE of each species. Pn differed significantly among the five species (p < 0.05). However, there was no significant difference in Pn between L. sibirica and H. rhamnoides (p > 0.05). C. arborescens showed the highest Pn whereas U. pumila did the poorest. E differed significantly among the five species (p < 0.05). L. sibirica and U. pumila showed considerably lower E than other species. Thus, WUE values of coniferous species such as L. sibirica and P. sylvestris were significantly greater than deciduous or shrub species such as U. pumila, C. arborescens and H. rhamnoides (p < 0.01). It may result that conifers showed relatively high water use efficiency than deciduous or shrub trees due to their lower transpiration rates, which resulted in morphological and physiological characteristics of their leaves. This may indicate that L. sibirica and P. sylvestris can be widely used for rehabilitation works in Mongolia attributed to their dominant distributions but also their high drought-resistance properties.

• The Plant Pathology Journal
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• v.22 no.2
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• pp.119-124
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• 2006

Kudzu vine(Pueraria montana var. lobata) is an invasive climbing woody vine that envelops trees and shrubs, pressing physically and shutting out sunlight, which needs to be controlled. Kudzu vine pathogens were surveyed as a way to seek its biocontrol agents in 2002. Occurrence of a bacterial halo blight disease of kudzu vine was observed at several localities in Korea including Euiwang and Suwon in Gyeonggi Province, Daejon, and Gochang and Buan in Jeonbuk Province. Symptoms of brown to black spots with a surrounding yellowish halo appeared from June and lasted till the rainy season without much expansion, but accompanying often leaf blight and defoliation. Isolated bacteria were identified as Pseudomonas syringae pv. phaseolicola based on physiological and cultural characteristics, Biolog, fatty acid and 16S rDNA sequencing analyses. In artificial inoculation test, these bacteria produced the same halo spot symptoms on kudzu vine and bean plants. They also induced hypersensitive responses (HR) on tobacco, tomato, and chili pepper leaves. This is the first report of a bacterial disease of kudzu vine in Korea, and the bacterial pathogen can be used as a biocontrol agent against the pest plant.

• Korean Journal of Environment and Ecology
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• v.20 no.1
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• pp.70-74
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• 2006

To study for proper growing conditions of Hydrangea macrophylla var. acuminata, used as ornamental trees or sources of natural sweetenings and biological active compounds, two-year-old cuttings of the plant were subjected to different conditions, light intensity, watering, and fertilizing levels. Photosynthetic rates measured on October 2 differed significantly between two light intensity regimes, but the values measured on September 3 were not significantly different. Mean photosynthetic rates on the plot watered three times a week were higher than the cuttings on the plot watered once a week. Mean photosynthetic rates on the plot fertilized 200grams/cuttings were slightly higher than those of the cuttings on the control plot. Chlorophyll contents measured on August 2 and on September 3 were significantly different between the light intensity regimes. Chlorophyll contents measured on August 2 were significantly different between the moisture regimes, but not significantly different between the fertilizing levels. Means of leaf growth(length and width) measured the highest values on the plot watered three times a week, and on the plot in full-sun lighted.

• Journal of Korean Society of Forest Science
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• v.32 no.1
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• pp.73-86
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• 1976

Two individuals ($sp_1$, $sp_2$) of purple and one individual ($sd_1$) of red hearted flower were selected from 18 years old Hibiscus syriacus trees obtained from the seeds treated with colchicine, and their morphological and physiological characteristics were investigated and following results were obtained. 1. The somatic chromosome number of the selected individuals, $sp_1$, $sp_2$, and $sd_1$ were 2n=160, while that of the check tree was 2n=80, indicating that the selected individuals, $sp_1$, $sp_2$ and $sd_1$ were tetraploid. 2. Peroxidase isoenzyme bands of high activity in selected individuals, $sp_1$, $sd_1$ and check tree were mostly in cathode, fixed band was f and v bands, and frequency of each band and their activity were not different between selected individuals, $sp_1$ and $sd_1$ and check tree. 3. The flowers of $sp_1$ individual were large in size and more dark purple than check tree's. The flowers of $sp_2$ individual were not increased in size, but they were dark purple and red heart at the base of the petal was expanded to 2/3 of the petal length. The flower of $sd_1$ individual was also large and some of the red lines from the petal base were extended to 2/3 of the petal length, which was much longer than those of the check tree. 4. Thickess of leaves, length of guard cells, diameter of pollens, wood fiber lengths and woody fiber widths were all increased in $sp_1$, $sp_2$ and $sd_1$ as compared to those of the check tree. 5. Survival percentage of cuttings was 80% with $sp_1$ and 36% with $sd_1$, and their growth performance were inferior to control in their second growing season.

• Journal of Korean Society of Forest Science
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• v.111 no.3
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• pp.394-404
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• 2022

This study was conducted to optimize the amount of drip irrigation for Prunus×yedoensis Matsum., one of the major medium-sized landscaping trees used mainly for streetscapes and as ornamentals. The experiment was conducted in a container nursery, where we assessed the growth and physiological characteristics of 4- and 8-year-old seedlings watered at different rates (x) by a drip irrigation system. The relative growth rates (based on height and root collar diameter (RCD) measurements) were highest at 288 and 416 L/year/tree for the 4- and 8-year-old containerized seedlings, respectively. These age and treatment combinations also produced significantly different dry weight and seedling quality index values, indicating good growth. The two age groups had significantly different total root lengths, root diameters, and root volumes under these respective irrigation treatments. In addition, the 4-year-old containerized seedlings irrigated at 288 L/year/tree and the 8-year-old containerized seedlings irrigated at 416 L/year/tree had the highest activations in their chlorophyll contents. Overall, the results (differences in irrigation amounts affect the seedlings morphological relative growth, biomass growth, seedling quality, and physiological reaction) indicate that the optimal irrigation amounts for container-grown Prunus×yedoensis are 288 L/year/tree for 4-year-old (RCD class, 3cm) and 416 L/year/tree for 8-year-old (RCD class, 7 cm) containerized seedlings.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.4
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• pp.216-226
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• 2019

This study was to investigate the effect of the horse grazing intensity on the vegetation of the S. quelpaertensis, and the physiological changes of the horse. This experiment was conducted at the community of the S. quelpaertensis (altitude of 550m) with the grazing intensity of 1.0AU(500kg), 1.5AU(750kg) and 2.0AU(1,000kg) at 30m × 30m for one week, and then the growth characteristics of the S. quelpaertensis, the changes of the vegetation, the damages on trees and the changes in the physiological characteristics of the horses was investigated and compared before and after the horse grazing. As the results, the 2.0AU grazing land showed that the culm number had the inverse correlation (r=-0.902, P<0.01) to the other lands and the species diversity index of lower-level vegetation showed the correlation (r=0.773, P<0.01) as increasing the grazing intensity.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.199-212
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• 2014

The physiological responses of three common temperate species, Pinus densiflora, Fraxinus rhynchophylla, Sorbus alnifolia to elevated $CO_2$ was investigated using open top chambers with different $CO_2$ concentrations. Morphological (stomatal size, density and area) and physiological characteristics (maximum rates of photosynthesis, carboxylation and electron transport) were compared among trees grown under ambient, ambient ${\times}1.4$ (~550 ppm) and ambient ${\times}1.8$ (~700 ppm) $CO_2$ concentrations for last four years. Morphological responses were different among species. F. rhynchophyllar increased their stomatal size and S. alnifolia had higher stomatal density under elevated $CO_2$ than ambient. Stomatal area decreased in P. densiflora, whereas it increased in S. alnifolia. However, the maximum photosynthesis rate increased in all species up to 43.5% by S. alnifolia under elevated $CO_2$ and the enhancement increased with time. Even with four years of exposure to elevated $CO_2$, there was no sign of acclimation in the maximum carboxylation rate and the maximum electron transport rates in all species. Especially, S. alnifolia even showed the temporary increase of photosynthetic capacities in spring, when leaf nitrogen concentration was high with new leaf development. There was no significant differences in diameter growth rate in any species due to high variation in their tree sizes, however accumulated diameter and biomass for four years showed significantly increment in all species under elevated $CO_2$. For example, S. alnifolia showed 59% increase in diameter at the ambient ${\times}1.8$ (~700 ppm) compared to ambient.