• Horticultural Science & Technology
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• v.28 no.5
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• pp.796-801
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• 2010

This study was carried out to establish a system for mutation breeding by irradiation of gamma-ray in $Rosa$ $hybrida$ Hort. The rooted cuttings of two roses, 'Spidella' and 'Cabernet' were irradiated with different gamma-ray doses (0, 30, 50, 70, 90, 110, 130, 150 and 170 Gy) from a $^{60}Co$ source to reveal an optimal dose for induction of mutants. The irradiated plants were planted in a greenhouse, and investigated on the appearance of petal color mutants and shoot growth by gamma ray dose. The 50% lethal doses ($LD_{50}$) of plant were 110 Gy for 'Spidella' and 150 Gy for 'Cabernet', respectively. The 50% decrease dose of shoot length was observed at 70-90 Gy dose for 'Spidella', and 110 Gy dose for 'Cabernet'. Solid, chimeric and mosaic petal mutants with various colors were induced from pink petal of 'Spidella' and red petal of 'Cabernet' when 30-170 Gy dose was irradiated. The mutants obtained from 'Spidella' had white, ivory, pinky ivory, light pink and deep pink petal colors. The mutants obtained from 'Cabernet' had pink, deep pink, purple red (magenta), orange red and purple petal colors. It was suitable to irradiate 70-90 Gy dose for 'Spidella' and 90-110 Gy dose for 'Cabernet' for the induction of various mutants considering plant survival rate, shoot growth and mutant occurrence rate.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.237-242
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• 2004

The radioprotective effects of Melatonin and Ge-132 on acute hematopoietic injury was investigated in mice exposed to an acute whole-body radiation dose of 8 Gy. Melatonin was administered intraperitoneally 1 hour before irradiation at a dose of 200 mg/kg, and Ge-132 was administered orally from days 5 to 20 after irradiation at a dose 130 - 150 mg/kg/d. The radioprotective effects were evaluated for spleen using TUNEL assay, and in peripheral blood by counting lymphocyte & WBC. The 4 experimental groups (irradiation-only, melatonin pretreatment, Ge-132 posttreatment, and melatonin pretreatment plus Ge-132 posttreatment) were observed for survival analysis up to 30 days following irradiation. The apoptotic index (47.8% vs 45.9%, p=0.385), and the number of lymphocytes ($97/{\mu}{\ell}\;vs\;101/{\mu}{\ell}$, p=0.898) were not significantly different between the irradiation-only and the melatonin pretreatment group, But the number of WBCs ($147/{\mu}{\ell}\;vs\;306/{\mu}{\ell}$, p=0.010) was higher in the melatonin pretreatment group. The irradiation-only, melatonin, Ge-132, and melatonin plus Ge-132 treatments resulted in survival rate at 30 days of 21.4%, 100%, 35.7%, and 85.7%, respectively. The melatonin pretreatment group in survival analysis between groups was showed significantly higher survival than the irradiation-only(p=0.000), or Ge-132 posttreatment group(p=0.0003). These results indicate that the melatonin may have a potential as an effective radioprotector on acute hematopoietic syndrome following radiation exposure.

• Korean journal of applied entomology
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• v.2
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• pp.47-54
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• 1963

The chestnut gall wasp, Dryocosmus kuriphilus $Y^{ASUMATSU}$, has been recently distributed and chestnut trees have teen seriously damaged by this insects in Korea. However, this insect pest has not been investigated in Korea. This paper gives an account of field and Laboratory observations on the seasonal occurrence and the life history of the chestnut gall wasp, and the damage of the chestnut trees by. its insects. This study was carried out at Chungchungpukdo, Kangwon-do and Kyungi-do in Korea, from 1961 to 1963, inclusive. 1. The Chestnut gall wasp (Dryocosmus kuriphilus $Y^{ASUMATSU}$) has one generathion per year and females are only known. 2. The adult wasps were observed from late June to late July with peak of wasp emergence about early and middle July. Most of new adult wasps were coming out from, the galls in the morning rather than the afternoon. 3. Each wasp produced auerage 198.5 eggs and about 4.89 eggs was observed in each bud of the chestnut tree. 4, The egg period of wasps was about 30 days and they were hatching from July to August. 5. The larval period of wasps were from middle of August to middle of next June and pupation took places about early June to middle of July. 6. The adult wasps were ovipositing into the buds and from early May next year, galls were growing. They caused stunting of growth and no fruiting or dying of the chestnut tries. 7. The first observation of the wasp was made at Chaechun of Chungchung-pukdo in 1958. Up to 1963 this insects are distributed in Kangwon-do, Kyunggi-do, north part of Chungchung-pukdo and north part of Kyungsangpukdo

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.833-840
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• 1997

Differentiation and degeneration of spikelets in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in 5000$^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicles of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage, and investigated about formation position of the differentiation and degeneration spikelet within a panicle of 7 days after heading. The degeneration of spikelet appeared simultaneously throughout panicle just after closure of spikelet by the palea and lemma. Differentiated and degenerated spikelets per panicle were about 240, 80 for Milyang 23 and 87, 6 for Koshihikari, respectively. The spikelets degeneration in Milyang 23 was mainly on the secondary and tertiary branch which were developed from primary branch of middle-basal panicle node and hardly not the spikelets of primary branch, and degeneration rate of secondary and tertiary rachis branch and spikelets for Milyang 23 were 2.5 times greater than those of Koshihikari. The proper relation equation between total differentiation or normal spikelets number per panicle(Y) and each rachis branch number were different between cultivars, Le., Y=5.5X$_1$＋3.0X$_2$ for Koshihikari as previously proposed, but those of Milyang 23, Y=5.7X$_1$＋3.5X$_2$＋2.8X$_3$ for total differentiation spikelets and Y=5.6X$_1$＋3.2X$_2$＋2.4X$_3$ for normally developed spikelets, where X$_1$, X$_2$, X$_3$ are number of primary, secondary, tertiary rachis branch, respectively.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.84-88
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• 2011

This study was established to investigate the effects of seeding depth and seeding time on the emergence, growth, and N production of Vicia tetrasperma and V. hirsuta in 2007 and 2008. All seeds of both species were gathered from Dangjin, Chungnam in late June of 2005 and stored for two year at room temperature. Both V. species began to germinate at the end of June, passed the winter with the seedling stage, rapidly increased their height in April and May, were in full bloom in May, and then withered after entering mid-June. V. hirsuta had higher emergence rate and growth compared to those of V. tetrasperma. The optimum seeding time and seeding depth for a cover cropping was from late August to early September and from 1 to 5 cm, respectively. V. tetrasperma and V. hirsuta had a satisfactory growth and provided 43.8 and $55.4kg\;ha^{-1}$of N, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.3
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• pp.223-228
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• 2011

The present study was conducted to determine the optimum in vitro culture condition for callus induction and plant regeneration from mature seeds of bermudagrass (Cynodon dactylon cv. Common). It was revealed that mature seeds cultured on MS medium supplemented with 2 mg/L 2,4-D, 0.5 g/L proline, 0.5 g/L casamino acid and 3 g/L Gelrite under light condition produced the highest percentage of callus formation (39.2%). The most suitable medium for plant regeneration from dehydrated calli was MS agar medium supplemented with 0.5 mg/L 2,4-D, 2 mg/L BA, 0.5 g/L proline, 0.5 g/L casamino acid 3 g/L Gelrite which induced the highest percentage of calli forming shoots (57.7%). The frequency of callus induction and plant regeneration were the highest on sucrose, followed by maltose. The shoots were rooted at the highest rate (100%) when transferred onto 1/2 MS medium. Regenerated plants were morphologically uniform with normal growth pattern.

• Journal of the Korean Wood Science and Technology
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• v.47 no.6
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• pp.709-720
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• 2019

Due to global warming and abnormal climate, the incidence and scale of green tracts in rivers and water intake dam are increasing every year. Therefore, in this study, developed eco friendly positively charged Torrefied Wood Flour(TWF) coagulant by reusing wood damaged by blight as a natural material. In order to evaluate the effect of coagulant on water ecosystem, green algae contaminated water was collected and TOC showed high removal rate of 86% ~ 92% under 1% and 5% TWF C-PAM treatment condition. The $NH_3-N$ showed 53% removal efficiency. The average pH of the polluted water was 7.9 in the case of hydrogen ion concentration, and the pH of the treated water was in the range of 6.5 ~ 7.7, It was found to be suitable for water quality standards. In ecotoxicity tests, all the results of the experiment showed that both the number of green algae and that of treated water were not affected by the survival of the daphnia. Therefore, as a result of the analyzing, developed paste type TWF coagulants is considered to be able to remove algae using natural resources.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.88-99
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• 2009

This study was conducted to formulate management guidelines for Natural monumental old trees in Korea through survey of tree vigor and analysis of growing environments. A total of 20 old trees designated as natural monuments in Seoul, Incheon, and Gyeonggi Province were surveyed. The biological characteristics were surveyed with 4 items of species, ages and height of trees. The surrounding environments were surveyed with 2 items of location types and surroundings. The root conditions were surveyed with 2 items of denudation and molding depth. The health conditions were surveyed with 5 items of withering rate, cavity size, bark breakaway rate, damages by blight and insects, and growing tips. The soil conditions were surveyed with 6 items of PH, organic contents, valid phosphoric acid, transposal cations(K, Ca) and soil compaction. On the basis of outcomes of these research items, mutual relations among locations, growings and soil conditions of old trees were analyzed by carring out cross tabulation, correlation, and simple and multiple regression. Management guidelines were presented searching the factors effecting on the health of the monumental old trees. On the biological characteristics, the old trees designated as natural monuments were Pinus bungeana(4 trees), Juniperus chinensis(3 trees), Ginkgo biloba(3 trees), Poncirus trifoliata(2 trees). Actinidia arguta, Wisteria floribunda, Thuja orientalis, Quercus mongolica, Sophora japonica, Fraxinus rhynchophylla, Zelkova serrata, and Pinus densiflora. The tree height ranged from 4.2 to 39.2m, and root collar rounds ranged from 1.01 to 15.2m. On the surrounding environments, The location types ; Gardens(4), historical sites(5), residental sections(3) open agricultural fields(3), mountain hills(3), and near ocean beaches(1) and stream site(1). The surroundings ; 75% denudation of roots, molded more than 10cm except 4 trees(25%). On the health conditions, 1)Withering rate ; Ginkgo biloba(20%) in Yongmoon temple, (5%) in Saki-ri, kanwha-gun, and others had no withering rate. 2) Cavity size ; all subject had $5{\sim}100cm^3$ of cavity. 3) Bark breakaway rate ; Pinus bungeana in Soosong-dong, in the shrine of Confucius, in Samchung-dong, especially high rate of cavity(5~50%) in Seoul area and in Saki-ri, Kangwha-gun were high 45% brakeaway rate. 4) Damages by blight and insects was slight due to managements. 5Growing tips ; In cases of Juniperus chinensis in Changdeok palace and SunnogDang, seoul, growing tips were 1/2, presumably cause by air pollution, and in cases of Fraxinus rhynchophylla in Paju city and Pinus densiflora in BacksaDorip-ri, Icheon city, growing tips were fine, presumably because there were no moldings. On the Soil conditions, Soil pH ranged from 5.2 to 8.3, organic matter contents from 12% to 56%, phosphorus contents from 104 to 618ppm, soil compaction ranged from 7 to 28mm( among them, Denudation was severe with 21~28mm soil compactions in cases of Pinus bungeana in Soosong -dong, Thuja orientalis in Samchung -dong, Ginkgo biloba in the shrine of Confucius and in Yongmoon temple.) Results of cross tabulation, correlation, and regression analysis showed that molding depth was the most serious factor to deteriorate the tree vigor and cambium conductivity. In addition, soil acidity, organic matter contents, disease and insect damages and cambial detachment were also related to the tree vigor. Additional research of these relationships will be needed to conduct more detailed studies. Based on the relationships between the tree vigor and growing environments, it is considered that old trees should be managed to give them more growing spaces and less abuses. Also, molded soils should be removed and further soil-molding around the tree collar should be prohibited. For the construction of systematic management and removal of harmful factors, appropriative management according to spices, persistent monitering of damaged cases and construction of management system through the accumulation of data on the relationships of soil conditions are required.

• Journal of Wetlands Research
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• v.17 no.1
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• pp.62-74
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• 2015

Urban areas are variously under threat including deterioration of ecological functions. Many pond wetland types have been created as part of an effort to improve and restore this urban environment. This study was arranged to examine improvement plans of wetlands in urban areas by analyzing semi-natural wetlands in farm areas. As for environment for water quality, it suggested the inflow of natural water neighboring rivers or the direct inflow of rain as the improvement plans. The result which analyzed soil pH, OM, and T-N content of the soil environment mentioned that urban areas supplied artificial sluices, removed apoptotic bodies, and used artificial soil and waterproofing materials and use of natural materials in design and construction, the sluice state of the natural form, and negligence of autumn plants were suggested as the improvement plans. Florae appeared in the subject sites of the study have found that there are 35 families 69 species in urban areas and 53 families 142 species in rural areas. As the average has found that there are 18.5 families 29.3 species in 4 urban areas and 26.3 families 53.5 species in 4 rural areas, the big difference between them was analyzed. As the cause has found that there are differences in yearly plants in farming areas when compared to urban areas, creation of various basic environments including soil and water quality was suggested to make yearly plants settle down widely. Naturalized plants have found that there are no big differences between urban areas and rural areas. However, the average of the naturalized ratio in urban areas is 17.4% as the naturalized plants are about 1/4 of the appeared plants. As it was analyzed to be higher than 7.7%, the average of the naturalized ratio in farming areas as the big difference, creation of various inhabiting environments was suggested to make more yearly plants appear like the analyzed result of the life type. Consideration of placement, materials, and inhabiting environments was suggested to make creation of wetlands well appreciated to improve functions of wetlands in urban areas. It is expected that the above results of the study will be utilized in creation and improvement of the pond wetlands which can play a huge role in increase and improvement of biological diversity in urban areas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.511-520
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• 2014

Kenaf (Hibiscus cannabinus L.) was recognized as a potential source of forage. To reduce the production cost, we should insure large cultivation area. The one of the best candidate places to expand the useful kenaf production was 'Saemangeum' reclaimed land. To confirm the possibility of kenaf growth in reclaimed land, we seeding and cultivated the kenaf in 'Saemangeum'. The germination percentage of kenaf on 5.0 dS/m soil salinity was 18%. It is less 66% than that of 4.0 dS/m soil salinity and at 6.0 dS/m, the germination percentage of kenaf was under 10%. The growth and development of kenaf in reclaimed land grew worse with increasing soil salinity. The stem diameter which the most important factor that decide the value and yield of product was upper 2.6 cm when soil salinity maintained under 4.0 dS/m, but if soil salinity marked over 4.0 dS/m, the stem diameter of kenaf was drop under 2.0 cm and it deteriorate the number of leaves per plant by 20~46%. The necrosis on older tip and marginal leaves were noted approximately first month after seeding which was correlated directly with the salinity levels of reclaimed soil. Reduction of total yield was coincide with increasing levels of EC. If soil salinity over 5.0 dS/m, the amount of decreased by soil salinity was 51% than that of non-reclaimed region. The allowable soil salinity level of which could be maintained within 20% reduction rate was 4.2 dS/m. Consequently kenaf can be grown successfully with moderately saline soil condition. However, salt levels in excess of 4.2 dS/m severely have restricted plant growth and development and will result in significant yield reduction.