• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.69-76
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• 1995

Cold acclimation involves changes in gene expression. BN28 and BN115 are two genes which are regulated by cold temperature and assumed having roles in cold acclimation. The objectives of this experiment was to explore the expression of BN28 and BN115 under field conditions. Six winter cultivars were planted at three different dates during the fall. The expression of the genes was determined by northern blot analysis of total RNA taken from leaves 15 to 30 day-intervals after planting. The expression of the two genes was detected within 15 days after planting well before onset of freezing tolerance in plants. This suggestes either their expression was a prerequisite of the freezing tolerance or their expression was regulated by other environmental factors as well as temperature. Two genes showed a different expression pattern suggesting they had a different regulatory system. Although timecourse increase in expression of the cold-regulated genes was matched with increase in freezing tolerance, the difference of expression in cultivar level at specific times of measurement was not correlated with freezing tolerance at the moment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.150-156
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• 1995

Planting date is the most important factor in determining winter survival of Crop plants. The objective of this study was to explore the effect of planting date on the development of freezing tolerance and winter survival of canola. Six winter cultivars were planted at three different dates during the fall on the Michigan State University Research Farm at East Lansing, MI. Freezing tolerance was determined by ion leakage tests every 15 days after planting until middle of November. Winter survival was evaluated by counting the live plants in the fall and next spring. Planting date as well as cultivar treatment had a significant effect on freezing tolerance and winter survival A different pattern in development of freezing tolerance was observed for different planting dates. There was a high correlation between freezing tolerance and winter survival suggesting that freezing tolerance could be a useful predictor for winter survival.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.66-70
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• 1998

Four introduced forage rape (Brassica napus) cultivars, 'Akela', 'Ramon', 'Sparta', and 'Velox' and a leading rapeseed cultivar, 'Hallayuchae' were grown at nitrogen (N) rates of 0, 100, 250, 300, 350, and 400 kg/ha to (i) select forage rape cultivars adapted best to Cheju area, and (ii) determine the optimum N rate for the best cultivars. Days from seeding to flowering across the cultivars increased 190 to 195 days as N rate increased from 0 to 400 kg/ha. Average days to flowering of six cultivars ranged from 182 to 198 days. Plant height increased as N rate increased up to 300 kg/ha and then decreased with a further increase in N rate and ranged from 159 to 174 cm among the cultivars. The optimum N rate for the greatest dry matter yield of five cultivars ranged from 222 to 258 kg/ha. Sparta showed the greatest dry matter yield (35.79 Mg/ha), followed by Akela, Hallayuchae, Velox, and Ramon. As N rate increased, crude protein content linearly increased but crude fiber content declined curvilinearly. Akela and Sparta had higher protein content than the other cultivars did. The forage cultivars had lower crude fiber content than the oilseed cultivar Hallayuchae did. Our results demonstrated that Sparta was best adapted to Cheju area and the optimum N rate for Sparta was about 220kg/ha.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.137-146
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• 2007

The substitution of fossil fuels with biofuels has been proposed by the European Union (EU) as part of a strategy to mitigate greenhouse gas emissions from road transport, increase security of energy supply and support the development of rural communities. Vegetable oils and their derivatives (especially methyl esters), commonly referred to as 'biodiesel', are prominent candidates as alternative diesel fuels. They have advanced from being purely experimental fuels to the initial stages of commercialization. They are technically competitive with or offer technical advantages compared to conventional diesel fuel. However, several problems remain including economics, combustions, some emissions, lube oil contamination, and low-temperature properties. Therefore, quality control of fuel-related properties of biodiesel is needed to obtain consistent engine performance by fuel users. The quality of the fuel is affected by the oil composition. Rapeseed oil has been targeted for fuel use because it produces an oil with a close-to-optimum set of fuel characteristics. In this paper we have reviewed past and current efforts, both by traditional seed-breeding methods and by genetic engineering, to modify rapeseed oil quality and yield.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.299-307
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• 2013

A radish (Raphanus sativus L.) polygalacturonase-inhibiting protein (PGIP) gene was cloned and compared to the PGIP gene (BrPGIP2) from Chinese cabbage (Brassica rapa ssp. pekinensis) in order to gain more information on controlling a disease and improving produce quality. To clone the radish PGIP gene, primers were designed based on conserved sequences of two PGIP genes (BnPGIP1 and BnPGIP2) from rape (B. napus L. ssp. oleifera), Chinese cabbage and Arabidopsis thaliana. PCR cloning was performed with cDNA from the stigma of radish 'Daejinyeoreum' as a template to confirm DNA fragments which were about 600 base pair in size. Sequence analysis revealed 84.1% homology with BrPGIP2 and 70.1% with BnPGIP1. DNA walking was conducted to confirm the open reading frame of 972 bp, and the gene was named RsPGIP1. RsPGIP1 consisting with 323 amino acids (aa) has a high leucine content (54/323) and contains 10 leucine-rich repeat domains, as do most BrPGIPs of Chinese cabbage. The gene expression of RsPGIP1 was induced by abiotic stresses and methyl jasmonate. It showed enrichment in the stigma and the primary root than a leaf. Cloning RsPGIP1 will aid to further apply practices on postharvest quality maintenance and disease control of the root.

• Korean Journal of Plant Tissue Culture
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• v.24 no.2
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• pp.93-97
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• 1997

For the molecular genetic study of cold tolerance mechanism in plants, a cDNA encoding fatty acid desaturase (fad3), converting linoleic acid (18:2, $\omega$-6) to linolenic acid (18:3, $\omega$-3), was isolated from $\lambda$ZAPII Arabidopsis thaliana cDNA expression library by plaque hybridization using fad3 cDNA probe derived from Brassica napus. A 1.8 kb-EcoRI fragment from a lambda clone showing a strong positive hybridization signal was subcloned into pGEM7 and analyzed for its nucleotide sequence. From deduced amino acid sequences, the fad3 gene was revealed to have an open reading frame(ORF) consisting of 386 amino acids with a molecular mass of 44,075 Da. The fad3 gene was compared to chloroplast $\omega$-3 fatty acid desaturase (fad7) and endoplasmic reticulum Δ12 fatty acid desaturase (fad2) to show 70% and 58% amino acid sequence homology, respectively, Especially, amino acids of internal (82 to 151) and carboxy terminal (276 to 333) regions were highly conserved, implying their requisite role for enzymatic functioning of fatty acid desaturases. IPTG-induced fad3 cDNA expression in E. coli cells was suggested to be toxic to bacterial growth.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.1
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• pp.67-76
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• 2007

The conclusion of free Trade Agreement between South Korea and USA can become a serious threat to the Korean agriculture. On the strategic scheme the foodstuffs is the basis for protection of the state sovereignty. The Amur oblast of Russian Federation is region, which can supply South Korea cheap and good qualitative feeds. It means South Korea should create agricultural cooperation with the Amur oblast of Russian Federation with the purpose to begin organic agriculture in this area and it will help South Korea to counteract a quantitative attack on Korea from the side of american agricultural production. In the Amur oblast there are following fodder crops; Alfalfa, Smooth brome grass (gromus adonis L.), Siberian couch grass, Sudan pass, Colza rape (Brassica napus) and Amaranth (Avfranthus). In the same area also exist oatmeal, wheat, corn and barley, which is possible to use for feeds. All these above written cultures are cultivated organically, therefore it is possible to use them as organic forages in South Korea. It is very important to know system of crop rotation in the Amur oblast. There is a scheme of crop rotation, which is connected with increase and preservation of fertility of soil, maintenance of growth of productivity of agricultural cultures and reception of high-quality production. It is necessary to begin organic agriculture in a southern part of Amur oblast, where, in 2001 year, 97% of all sowing areas was concentrated. The acidity degree of soil in this part is not high ($ph5.1{\sim}5.5$), therefore does not require liming.

• Journal of Ecology and Environment
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• v.36 no.3
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• pp.167-172
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• 2013

A Two-year field experiment was carried out in 2009 and 2010 to evaluate the effects of different densities of wild oat and nitrogen (N) rates on oilseed rape yield and yield components. Experimental design was split plot with three replications. Increased nitrogen rates up to 150 kg N/ha caused an increase in oilseed rape grain yield in weed-free plots (4.26 t/ha; 1t = $10^3kg$), while even at the lowest density of wild oat (15 $plants/m^2$), increasing N fertilizer only up to 50 kg/ha led to a significant increase in grain yield. Wild oat growth was favored by high levels of N. Intraspecific competition reduced biomass, 100-seed weight and number of tillers of wild oat. Both lower N rate and intraspecific competition had negative effect on wild oat growth but the weed was still able to produce a considerable number of tillers and vigorous seeds. It showed that wild oat possess a notable adaptive plasticity and can allocate a greater proportion of its resource toward reproductive organs even under resource shortage conditions and, thus, it may increase the competitive ability of the weed over the crop.Our results suggest that effective weed management should be done to prevent wild oat seed production in crops preceding oilseed rape as well as to control the weed at early season in oilseed rape fields.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.2
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• pp.198-202
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• 1984

This experiment was conducted to investigate the oil content, change of fatty acid composition affected by ferlilizer levels in upland and paddy field cultivation of rapeseed, The oil content with the fatty acid such as palmitic, linoleic and linolenic was increased in the winter crop on drained paddy field compared with those of upland field in which oleic and stearic fatty acid was increased. Unsaturated, good quality fatty acid content such as oleic and linoleic acid in the cultivation of upland field was higher by 2-5% than those of paddy field. Oleic and linoleic fatty acid contents showed increased with increment of nitrogen fertilizer up to 15kg/10a, and showed same trend until 80kg/ha fertilization level of phosphate and potassium in upland field but there was no effect in paddy field cultivation.

• Korean Journal of Veterinary Research
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• v.15 no.2
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• pp.279-285
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• 1975

The experiments were conducted to isolate the etiogical agent and to survey the distribution of Nosema disease in honey bees. The results obtained were as follows: 1. The etiological agent of the so-called "crawling disease" in honey bees characterized by the symptoms of crawling, diarrhea, and enteritis etc. was first isolated and identified with Nosema apis (Zander 1909) in Korea. 2. 455 colonies were randomely sampled and surveyed in 4,766 bee colonies out of 56 apiaries and 51 colonies (11.2%) out of 455 bee colonies were infected with N, apis. 3. Infection rates according to the period of honeyflow as follows: Brassica napus (Apr.): 25/130 colonies (18.4%) Rohinia pseudoacacia (May) : 8/55 colonies (14.%) Trifolium repels(Jun.): 15/99 colonies (13.6%) Castanea crenate (Jul.): 3/46 colonies (6.5%) Lespedeza bicolor(Aug.): 0/60 colonies (-) Fagopyrumesculentum(Sept.) & Perilla frutescens(Oct.) 0/65 colonies (-) 4. The typical clinical signs of Nosema disease were appeared on loth day after N. apis was orally administered with the level of $16{\times}10^4$ spores/ml to the healthy adult bees. Spores could be harvested with the level of $121{\sim}236{\times}10^4$ spores/ml on 10th day and $392{\sim}429{\times}10^4$ spores/ml on 15 days after infection. 5. In adult honey bees infected with N. apis artificially the 50% lethal day of life-span was 9 to 10 days and 100% lethal day was 16 to 19 days. However, in the control 50% lethal day was 19 to 23 days and 100% lethal day was 31 to 33 days.