• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.1-6
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• 1975

From the cross Tongil$^2//IR833/IR1317$ glutinouse rice lines wx 126 were bred. Some of these lines were earlier than standard variety and later than glutinous check variety. Some of them yielded as much as standard variety and showed better resostances to blast, stripe deseases and smaller brown plant hopper than standard variety. It was sosscussed that, theough the vreedong procedure, following points were proved, 1)back-cross program in roce breeding was effocoent, 2)semi-dwarf plant type of "Tongil" has high yielding poteneoality and 3) the variety "Tongil" was a good for recurrent parent for back-cross program. back-cross program.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.528-530
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• 1998

The hardwood cutting of Hibiscus syriacus was studied by using 54 different cultivars. In the evaluation of rooting ability and shoot growth, there were much differences between cultivars or groups classified by flower types. The outstanding rooting ability was found in cultivars such as 'Comte de Haimont', 'Hanol-tanshim', 'Hyangdan', 'Nabora', 'Saimdang', whereas 'Ilpyontanshim', 'Lucy', 'Paedal', 'Sohoyang' and other several cultivars showed poor characteristics in their rooting. The longest shoot was observed in 'Hanoltanshim', 'Kreider Blue', 'Nabora', 'New Hamabo', 'Nunbora', while 'Chossarang', 'Lucy', 'Shintaeyang', 'Youngkwang', etc. showed very short shoots. As a result of comparison among three different flower types, semi-doubled flower type showed the most extent of rooting ability and shoot growth.

• Journal of The Korean Astronomical Society
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• v.39 no.4
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• pp.129-138
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• 2006

A period study of the semi-detached eclipsing binary system W Delphini based on the extensive series of minimum timings covering more than a century(109 years) indicates a cyclic(O-C) variation of the system. This variation can be explained as due either to (1) stellar magnetic activity cycles of the cool subgiant G5 secondary component of the binary with a subsurface magnetic field equals to 3 kG, or (2) a long-term orbital period increases with a rate of $1.68{\times}10^{-8}$ day/cycle caused by a mass transfer rate of $4.9{\times}10^{-8}M_{\odot}yr^{-1}$ from the less to more massive component modulated by a light time effect due to a hypothetical third body with period of $53.4{\pm}1.06$ years. The former explanation is more recommended than the later one since the obtained third body mass value($M_3=1.58\;M_{\odot}$) is quite large but it can not manifest itself observationally and also it cannot be a white dwarf. In the contrary, from the magnetic activity point of view, the obtained characteristics are in good consistent when applying Applegate(1992) mechanism. However, further precise photometric and CCD observations for minima timings with brightness determinations are needed to confirm the present solution.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.502-511
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• 1994

Investigated were the relationships between plumule elongation characteristics and seedling emergence of 98 varieties including native, improved and red rice varieties of Korea, and varieties from U.S.A., Italy, Japan, etc. under proper and excess soil moisture regimes. Under excess soil moisture condition the seedling emergence and establishment rates were much lower in most of the varieties and the seedling emergence rates were delayed substantially in all varieties employed. The seedling emergence rates were lowest in dwarf and some semi-dwarf varieties showing poor plumule elongation under proper soil moisture condition. The seedling emergence and establishment rates were significantly correlated with the length of mesocotyl, coleoptile and incomplete leaf under both soil moisture regimes, and with the lower first and second internode length under excess soil moisture condition. Average emergence duration showed significant negative correlation with the length of mesocotyl, coleoptile and incomplete leaf under both soil moisture regimes and significant positive correlations with the first and third lower internode length. Based on the standardized partial regression analysis only the variations of mesocotyl and coleoptile length contributed significantly to the varietal difference in seedling establishment rate, and so did the variations of mesocotyl and incomplete leaf length to the varietal differences in emergence speed. In conclusion varieties with greater elongation characteristics of mesocotyl, coleoptile and incomplete leaf are desirable for higher and speedy seedling establishment in dry-direct seeding.

• Journal of Astronomy and Space Sciences
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• v.22 no.3
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• pp.197-210
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• 2005

Results of 7 nights of CCD VR photometry of the intermediate polar 1RXS J062518.2+733433 obtained at the Korean 1.8m telescope are reported. The corrected ephemeris for the orbital minimum is BJD (Orb.min) = 2453023.6159(42)+0.1966431(33) (E-1735). The corrected ephemeris for the spin maximum is BJD (spin max) = 2452893 78477 (10)+0.01374116815 (17) (E-15382) (cycle numbering corresponds to that of Staude et al.2003). The variations of the shape of the individual spin variations are highly correlated in V and R. The phase of the spin maximum is found to be dependent on the orbital phase. The corresponding semi-amplitude of sinusoidal variations of phase is $0.11{\pm}0.03.$ This new phenomenon is explained by the changing viewing conditions of the accreting magnetic white dwarf, and should be checked in further observations this star and for other intermediate polars. To avoid influence of this effect on the analysis of the long-term spin period variations, the runs of at least one orbital period are recommended. Results of time series analysis are presented in tables.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.1
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• pp.50-54
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• 2000

The elongation of mesocotyl and coleoptile plays important roles in the seedling emergence and stand establishment of dry direct-seeded rice. Experiments were carried out to elucidate the effects of seed-presoaking treatments of GA$_3$ and some inorganic salts on the mesocotyl, and coleoptile elongation of rice. Seed-soaked GA$_3$ promoted the elongation of mesocotyl, but little effect on the coleoptile elongation. The stimulation effects of GA$_3$ were found to be enhanced by addition of CaCl$_2$ However, the sole treatment of CaCl$_2$ showed no stimulating effect on the mesocotyl and coleoptile elongation. Mesocotyl elongation was most prominent in the combined treatments of 50ppm GA$_3$ with 100 mM CaCl$_2$. The synergistic effects of GA$_3$ and CaCl$_2$ on mesocotyl elongation varied with varietal groups. The stimulating effects of GA$_3$ were enhanced significantly by the addition of CaCl$_2$ in japonica varieties, Dongjinbyeo, Ilpumbyeo and Milyang 95, and tall indica variety, Labelle, but not in semidwarf Tongil type varieties, Tongilbyeo, Milyang 23, and Nampungbyeo, and semi-dwarf indica, Short Labelle. The promoting effects of GA$_3$ on the mesocotyl elongation were decreased in proportion to the lowered osmotic potential by PEG 6000 on the contrary to CaCl$_2$ This implies that the synergistic effects of CaCl$_2$ with GA$_3$ on mesocotyl elongation was not caused by osmotic potential lowered by CaCl$_2$ addition but by the salt itself. Salts such as Ca(NO$_3$)$_2$, MgCl$_2$ BaCl$_2$, NaCl, KCl and KNO$_3$ showed the synergistic effects with GA$_3$ on mesocotyl elongation as well. The degree of synergistic effects showed no differences among salts tested, implying that there is no specificity of ions constituting the salts.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.1
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• pp.35-40
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• 1982

New malting barley variety" Doosan #8" is a short culm, lodging registance, high tillering, good quality and high yielding variety. This variety was developed from the cross 'Tai Chung 2 rowed barley #1 \times Deba abed' made in 1972 at Sacheon Malting Barley Experiment station, Doo San Fann's Co. This variety was determined to recommend to the all malting barley production areas in southern part of Korea from 1981. of Korea from 1981.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.486-486
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• 2018

During the post green revolution era, wheat and rice were the main crops of concern to cater the food security issues of Pakistan. The use of semi dwarf high yielding varieties along with extensive use of fertilizers and surface and ground water lead to substantial increase in crop production. However, the higher crop productivity came at the cost of over exploitation of the precious land and water resources, which ultimately has resulted in the dwindling production rates, loss of soil fertility, and qualitative and quantitative deterioration of both surface and ground water bodies. Recently, during the past two decades, severe climate changes are further pushing the Pakistan's wheat-rice system towards its limits. This necessitates a careful analysis of the current crop water requirements and water footprints (both green and blue) to project the future trends under the most likely climate change phenomenon. This was done by using the FAO developed CROPWAT model v 8.0, coupled with the statistically-downscaled climate projections from the 8 Global Circulation Models (GCMs), for the two future time slices, 2030s (2021-2050) and 2060s (2051-2080), under the two Representative Concentration Pathways (RCPs): 4.5 and 8.5. The wheat-rice production system of Punjab, Pakistan was considered as a case study in exploration of how the changing climate might influence the crop water requirements and water footprints of the two major crops. Under the worst, most likely future scenario of temperature rise and rainfall reduction, the crop water requirements and water footprints, especially blue, increased, owing to the elevated irrigation demands originating from the accelerated evapotranspiration rates. A probable increase in rainfall as envisaged by some GCMs may partly alleviate the adverse impacts of the temperature rise but the higher uncertainties associated with the predicated rainfall patterns is worth considering before reaching a final conclusion. The total water footprints were continuously increasing implying that future climate would profoundly influence the crop evapotranspiration demands. The results highlighted the significance of the irrigation water availability in order to sustain and improve the wheat-rice production system of Punjab, Pakistan.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 1997.06a
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• pp.23-49
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• 1997

This is a progress report of rice biotechnology including development of gene transformation system, gene cloning and molecular mapping in rice. The scope of the research was focused on the connection between conventional breeding and biotech-researches. Plant transformation via Agrobacterium or particle bombardment was developed to introduce one or several genes to recommended rice cultivars. Two chimeric genes containing a maize ribosome inactivating protein gene (RIP) and a gerbicide resistant gene (bar) were introduced to Nipponbare, a Japonica cultivar, and transmitted to Korean cultivars. The homozygous progenies of herbicide resistant transgenic plant showed good fertility and agronomic characters. To explore the genetic resourses in rice, over 8,000 cDNA clones from immature rice seed have been isolated and sequenced. About 13% of clones were identified as enzymes related to metabolic pathway. Among them, twenty clones have high homology with genes encoding enzymes in the photorespiratory carbon cycle reaction. Up to now about 100 clones were fully sequenced and registered at EMBL and GenBank. For the mapping of quantitative tarits loci (QTL) and eternal recombinant inbred population with 164 F13 lines (MGRI) was developed from a cross between Milyang 23 and Gihobyeo, Korean rice cultivars. After construction of fully saturated RFLP and AFLP map, quantitative traits using MGRI population were analyzed and integrated into the molecular map. Eighty seven loci were determined with 27 QTL characters including yield and yield components on rice chromosomes. Map based cloning was also tried to isolate semi-dwarf (sd-1) gene in rice. A DNA probe, RG 109, the most tightly linked to sd-1 gene was used to screen from bacterial artifical chromosome (BAC) libraries and five over lapping clones presumably containing sd-1 gene were isolated. Rice genetic database including results of biotech reasearch and classical genetics is provided at Korea Rice Genome Server which is accessible with world wide web (www) browser. The server provides rice cDNA sequences and map informations linked with phenotypic images.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.203-208
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• 1984

This study was investigated to know the possible linkage relationship between blast resistance gene and plant height gene in rice. Two resistant varieties, Tadukan and Tetep were crossed with six susceptible semi-dwarf tester lines. Progenies derived from the crosses were inoculated with spray method at 3-4 leaf stage with blast races, C-8$^{+t}$ and T-2$^{+t}$. The results indicated that: (1) Resistance of Tadukan and Tetep to the C-8$^{+t}$ was controlled by a single dominant gene, respectively. (2) Resistance of Tadukan and Tetep to the T-2$^{+t}$ was expressed by complementary gene action between two dominant genes, respectively. (3) No linkage relationship was found between resistance gene and plant height gene of both Tadukan and Tetep when tested with C-8$^{+t}$ and T-2$^{+t}$, respectively.espectively.