• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.1-5
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• 2016

BACKGROUND: Burcucumber(Sicyos angulatus L.) is an invasive plant species and disturbs ecosystems in Korea. The main method for prevention of burcucumber is cutting or pulling out. However, the studies accounting for the use of the by-product of burcucumber after cutting remain incomplete. Thus, the aim of this study was to investigate the applicability of burcucumber as a substitute for nitrogen fertilizer.METHODS AND RESULTS: Burcucmber plants only including stem, leaves, and petiole were collected from the Sky Park in Seoul and divided in to three categories based on the length of stem of burcucumber; 10-30 cm, 30-100 cm, and 100-200 cm. And they were input into soil with 20 kg-N/10 a. After 4 weeks aging, chemical properties of treated soils and the productivity of lettuce(Lactuca sativa L.) were examined. Both the inorganic nitrogen contents in soils and the growth of lettuce were increased with the decreases in length of burcucumber standing for young plant. And the inorganic nitrogen content and the productivity of lettuce were positively correlated(r= 0.9409).CONCLUSION: The C/N ratio of burcucumber was low, indicating fast decomposition and nitrogen supplying rate, resulting in the increase in lettuce growth. Burcucumber could be a good substitute for nitrogen organic fertilizer.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.225-229
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• 2006

This study was conducted to screen herbicidal activity of Korean native plants which could be used for the development of new natural herbicides. Fifty-five plants were collected from Wan and Jeju islands in Korea and their methanol extracts were obtained. Herbicidal activity of methanol extracts were determined by seed bioassay using rape (Brassica napus L.) seedlings. Among fifty-five species, five plants were highly herbicidal ($GR_{50}$ < 1,000 ${\mu}g\;g^{-1}$): Clematis apiifolia A. P. DC.; (811 ${\mu}g\;g^{-1}$), Euscaphis japonica (THUNB.) KANITZ (867 ${\mu}g\;g^{-1}$), Hibiscus mutabilis L. (988 ${\mu}g\;g^{-1}$), Phyllostachys pubescens MAZEL (778 ${\mu}g\;g^{-1}$), Yucca recurvifolia (857 ${\mu}g\;g^{-1}$). Twenty-seven plants were shown moderately herbicidal (1,000 < $GR_{50}$ < 2,000 ${\mu}g\;g^{-1}$), however, twenty-three plants were not shown any herbicidal activity.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.166-173
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• 2010

The purpose of functional genome research is to identify biological function of useful gene and to give an agricultural value in plant biotechnology. Brassica rapa is an economic crop which recorded 1,000 billion won of domestic market and 100 million dollar of exports and it produces 2.5 million ton in 50,000 ha as a major ingredient of representative Korean food, Kimchi. Furthermore, it is very important crop economically and commercially because Korea is major seed exporter. The fact that Multinational Brassica Genome Project (MBGP) was launched and Arabidopsis thaliana, affiliated to same genus with B. rapa, has been fully sequenced activated functional genome research of B. rapa. Besides new technologies related to gene function analysis keep developing, many results are reporting every year by international research including Korea. This review paper introduces development of Chinese cabbage mutants which is a first step in functional genome research, variant phenotypes of mutants, flanking DNA analysis in B. rapa genome, gene identification, gene analysis using microarray, and representative researches.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.264-270
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• 2017

Brassinosteroid (BR), a plant steroid hormone, plays a critical role in the growth and developmental processes through its canonical signaling and crosstalk with various internal and external signaling pathways. Recent studies have revealed the essential interplay mechanisms between BR and ABA during seed germination and early seedling establishment. However, molecular mechanisms for this important signaling crosstalk are largely unknown. To understand the crosstalk between BR-mediated signaling pathways and ABA functions during early seedling development, we carried out a comparative genome-wide transcriptome analysis with an Agilent Arabidopsis $4{\times}44K$ oligo chip. We selected and compared the expression patterns of ABA response genes in ABA-insensitive bes1-D mutant with wild type seedlings on which ABA was exogenously applied. As a result, we identified 2,353 significant differentially expressed genes (DEGs) in ABA-treated bes1-D and wild type seedlings. GO enrichment analysis revealed that ABA signaling, response, and metabolism were critically down-regulated by BR-activated signaling pathways. In addition, the genome-wide transcriptome analysis data revealed that BR-regulated signaling pathways were tightly connected to diverse signal cues including abiotic/biotic stress, auxin, ROS etc. In this study, we newly identified the molecular mechanisms of BR-mediated repression of ABA signaling outputs. Also, our data suggest that interplay among diverse signaling pathways is critical for the adaptive response of the plant to various environmental factors.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.381-391
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• 2009

Crop production can be secured by the cycle of green manure crops as an alternative of the chemical fertilizer. Recently, rapeseed (Brassica napus L.) has been cultivated in the south part of Korea for the production of biodiesel. In this research, we focused on recycling rapeseed residue, which is produced after harvesting the rapeseed for biodiesel, as a potential source of nitrogen to the succeeding crop. Pot experiment was conducted to evaluate the effects of winter rapeseed as green manure on mineralization and uptake of nitrogen to the succeeding corn (Zea mays L.). Result showed that total nitrogen and C/N ratio of rapeseed at the harvesting stage was 0.54% and 63, respectively. The incorporation of rapeseed without decomposition period slightly inhibited nitrogen uptake to the succeeding corn compared to those with 30 days decomposition period. The pH and EC values of soils increased by increasing the period of decomposition of rapeseed from 5.2 to 6.4 and from 0.05 dS/m to 0.21 dS/m, respectively. Significant amounts of $NH_4^+$ and $NO_3^-$ are released by incorporation of rapeseed. The succeeding corn took up 86% and 88% of inorganic nitrogen released from the rapeseed with and without decomposition period, respectively. The overall results suggested that the utilization of rapeseed residue as green manure can be an alternative source of nitrogen in corn-rapeseed double cropping system.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.853-863
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• 2014

This study was carried out to construct a DNA profile database of 100 strawberry cultivars using microsatellite markers. Two hundred seventy four microsatellite primer pairs were screened with a set of 21 strawberry cultivars with different morphological traits. Twenty five primer pairs were selected because they produced reliable and reproducible fingerprints. These primer pairs were used to develop DNA profiles of 100 strawberry cultivars. Three to thirteen alleles were detected by each marker with an average of 7.50. The average polymorphism information content varied from 0.331 to 841 (average 0.706). Cluster analysis showed that the 100 cultivars were divided into 7 major groups reflecting geographic origin and pedigree information. Moreover, most of the cultivars could be discriminated by marker genotypes. These markers will be useful as a tool for the protection of plant breeders' intellectual property rights in addition to providing the means to intervene seed disputes relating to variety authentication.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.229-235
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• 1971

Kwanok, Fujisaka #5, Paldal, and Suwon #82 as japonica type and IR-262 and CP-slo as indica type of rice seeds were selected for this experiment among varieties grown in Korea. Activities of crude enzymes extracted from germinating seeds of these varieties on malathion and p-nitrophenyl acetate as substrates, esterase zymograms with 1-naphthyl acetate as substrate, and some observations are summarized as follows: 1. Activities per unit volume of crude enzyme preparations on malathion were in the order of Kwanok>IR-262>Fujisaka #5>CP-slo>Paldal>Suwon #82. 2. Esterase zymograms on agar-gel electrophoretograms exhibited three to four bands two electrodes with little difference among varieties, nevertheless showing a wide and strongly-colored band toward cathode. Suwon #82 has a somewhat different pattern from others. 3. Enzyme activities per milligram protein with p-nitrophenyl acetate as substrate were in the order of CP-slo>IR-262>Paldal>Kwanok>Suwon #82>Fujisaka #5, indicating that activities of indica type are much stronger than those of japonica type, but not in agreement with results with malathion. 4. Malathion did not much inhibit the esterase activity at the concentration of 0.2PPM on electrophoretograms. 5. It is supposed that there is a complex esterase system hydrolyzing malathion and p-nitrophenyl acetate in germinating rice seeds.

• Research in Plant Disease
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• v.14 no.3
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• pp.201-204
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• 2008

We've been involved in collection and domestication of Agrimonia pilosa from 2005 to 2007. We observed agrimony powdery mildew caused by Sphaerotheca aphanis. The powdery mildew developed twice a year, in May to June and mid August to September on whole plants of A. pilosa plants, that is, leaves, stem and floral part. We sprayed the Cooking Oil & Yolk mixture (COY) to control the agrimony powdery mildew. When COY was single-sprayed to control agrimony powdery mildew, its control value was 26.9%. However when it was double-sprayed and triple-sprayed at seven days interval, its control value increased up to 80.8 and 82.7%, respectively. Upon the first spray, symptoms of powdery mildew disappeared within three days and suppressive effect of COY was persisted for only seven days. Thereafter, powdery mildew was relapsed to develop. However, on double to triple sprays, powdery mildew was suppressed more than 28 days after final treatment. Therefore, it is concluded that double spray of COY at seven days interval can control effectively agrimony powdery mildew.

• Research in Plant Disease
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• v.20 no.3
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• pp.201-205
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• 2014

Damping-off, caused by Rhizoctonia solani and Pythium ultimum, is a very important plant disease and affects seeds and seedlings of many plant species worldwide. To investigate control efficacy of Serenade formulation (1.34%, SC) against Rhizoctonia and Pythium damping-off diseases, seeds of chili pepper and cucumber were sown in soils inoculated with R. solani and P. ultimum and Serenade formulation was applied by soil-drenching with 9-, 19-, and 39-fold dilutions. Control values of Serenade formulation on Rhizoctonia damping-off of chili pepper was 58% and 29% for 9- and 19-fold dilutions, respectively. In the case of cucumber Rhizoctonia damping-off, Serenade treatments showed similar control efficacy with damping-off of chili pepper. On the other hand, control efficacy of Serenade formulation on Pythium damping-off of cucumber was less than control effects on Rhizoctonia damping-off. Only Pythium damping-off of chili pepper treated with 9-fold dilution Serenade was statistically different with untreated control. This result suggest that Serenade formulation could be effectively used for controlling Rhizoctonia and Pythium damping-off diseases.

• Research in Plant Disease
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• v.23 no.2
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• pp.202-205
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• 2017

Pink rot appeared in greenhouse-grown sunflower (Helianthus annuus L.) in Jeonju, Korea. The symptoms appeared as brown discoloration of sunflower head and progressed into stem in advanced stage. In order to investigate the causal organism of this disease, we isolated a fungus from the infected seeds and maintained the isolated fungal culture on potato dextrose agar medium. Conidiophores were simple or branched, 62.5 to $123.1{\mu}m$ long. Conidia were produced in basipetal chains, ellipsoidal to pyriform with oblique and prominent truncate basal scars, two-celled, hyaline and measured $10.2-21.4{\times}7.5-12.6{\mu}m$. The fungus was inoculated to a new sunflower plant and showed the typical blight on the leaves. Study of morphological characters, pathogenicity tests and sequence analysis revealed that the isolated fungus is confirmed to be Trichothecium roseum. To our knowledge, this is the first report of pink rot on sunflower caused by T. roseum in Korea.