• Microbiology and Biotechnology Letters
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• v.33 no.1
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• pp.16-23
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• 2005

In order to develop a new microbial fungicide using endophytic bacteria for the control of anthracnoses occurring on various crops, a total of 260 bacterial strains were isolated from fresh tissues of 5 plant species. After they were cultured in broth medium, their antifungal activities were tested for in vivo antifungal activity against cucumber anthracnose caused by Colletotrichum orbiculare. As the results, liquid cultures of 28 strains showed potent antifungal activities more than $90\%$ against cucumber anthracnose. At 3-fold dilutions of liquid cultures, 18 strains inhibited the development of cucumber anthracnose of more than $70\%$. They were further tested for in vivo antifungal activity against red pepper anthracnose caused by C. coccodes and in vitro antifungal activity against C. acutatum, a fungal agent causing red pepper anthracnose. Among 18 strains, a bacterial strain EB215 isolated from cucumber roots displayed the most potent antifungal activity against Colletotrichum species. It was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, Biolog test and 16S rDNA gene sequence. It also controlled effectively the development of rice blast (Magnaporthe grisea), rice sheath blight (Corticium sasaki), tomato gray mold (Botrytis cinerea), and tomato late blight (Phytophthora infestans). Studies on the characterization of antifungal substances produced by B. cepacia EB215 are in progress.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.280-286
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• 2009

To investigate anti-phytopathogenic fungal activity of Coptis chinensis, the methanol extract and its organic solvent fractions were prepared. Using the extract and the fractions, in-vitro spore-germination inhibition and mycelial-growth inhibition activities were evaluated against Colletotrichum gloeosporioides, Phytohpthora capsici, Pyricularia grisea, Rhizoctonia solani, Botryosphaeri dothidea, Glomerella cingulata, respectively. Treatment of the methanol extract (500 mg/mL) into the spore of phytopathogenic fungi completely inhibited germinations for 5 days, except B. dothidea, and showed strong antifungal activities against P. grisea and B. cinerea, and antioomycetes activity against P. capsici. The minimal growth inhibition concentrations of the methanol extract against P. grisea, B. cinerea and P. capsici were 300, 300, and 500 mg/mL, respectively. For practical application of C. chinensis in red-pepper field, the hot-water extract (1,000 mg/mL) was prepared in commercial facility, after evaluation of heat stability and solvent-extraction yields of antifungal substances. The 3-times leaf-spray of the extract from June to August, 2008 did not show any deleterious effect to red-pepper. In fact, the leaf-spray promoted plant growth including leaf, root and fruit. The average weight and rind of each fruit were increased to 119% and 117% comparison to those of without treatments. Our results suggest that C. chinensis is a useful source for control of red-pepper diseases and plant growth.

• The Korean Journal of Pesticide Science
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• v.7 no.4
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• pp.302-309
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• 2003

Disease control activities of 230 triazolyl quinoline derivatives were investigated against six plant diseases such as rice blast, rice sheath blight, tomato gray mold, tomato late blight, wheat leaf rust (WLR) and barley powdery mildew (BPM). New triazolyl quinolines, KSI-4315 and KSI-4317 exhibited a great in vivo control activities against WLR and BPM, and then were selected for further tests such as preventive, curative, systemic, and persistence against WLR and BPM. The KSI-4315 and KSI-4317 contained MeS moiety and MsO moiety in carbon 4-position, respectively. They possessed both preventive activity and curative activity against WLR and BPM. KSI-4317 showed the better control activity than KSI-4315 against BPM, while KSI-4315 represented the better antifungal activity against WLR. Good persistence of KSI-4315 and KSI-4317 were also observed against WLR and BPM. Persistence of KSI-4315 was similar to that of KSI-4317 on WLR, but KSI-4317 was superior to KSI-4315 on BPM in its persistence. Systemic disease control of KSI-4315 and KSI-4317 was investigated by examining translaminar activity from leaf-under-surface to leaf-upper-surface, systemic activities by leaf to leaf movement and the effect of drenching treatment. Systemicities of KSI-4315 and KSI-4317 were not observed in wheat, but KSI-4317 showed more predominant systemicity than KSI-4315 in barley. These results suggest that KSI-4317 would potentially control WLR and BPM in the fields.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.26-35
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• 2013

This study was conducted to select superior provenances of Scots pine (Pinus sylvestris L.) well adapted to Korean environment for timber production. In 1976, twenty-two provenances of Scots pine were introduced from Sweden and the seeds were sown in seed beds in March. After one year, the seedlings were transplanted to nursery beds. The resulting 1-1 seedlings of 22 provenances were planted at Whaseong in 1978. Randomized complete block design with 3 replications were used for test plantation. Each provenance was planted with 20-tree row plot in each block and at a spacing of $1.8{\times}1.8m$. The growth performance of each provenance was monitored up to 33-years after planting. There were significant differences among provenances in volume growth. F3001 provenance showed the best volume growth of 33-years after planting ($0.160m^3$), which was 2.2 times greater than that of the lowest provenance W2027 ($0.072m^3$). The ranking of provenances was stabilized after 14 years. Comparing to reference tree species, Japanese red pine (Pinus densiflora), all Scots pine provenances showed poor growth performance. In other words, volume growth of Japanese red pine at age 28 and 33 were 2.1 and 3.3 times greater than that of Scots pine, respectively. Moreover, survival rate of Scots pine was lower than that of Japanese red pine. Based on these results, it was suggested that Scots pine was not suitable to Korean environments. The cause of maladaptation of Scots pine and the implications of introduction breeding were discussed.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.301-307
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• 2015

High quality transplants are critical for success in crop production. Increasing numbers of growers purchase their transplants from specialized transplant producers instead of growing their own transplants. A drawback of purchasing transplants is the risk of deterioration to transplants during transportation from transplant producers to the growers. This study evaluates the influence of temperature on the quality of grafted tomatoes transplants (Solanum lycopersicum cv. Super Doterang), in order to propose optimum temperature condition for the transportation of grafted tomato transplants. Grafted tomato transplants with visible flower trusses were exposed to different air temperature ($10^{\circ}C$, $25^{\circ}C$, or $40^{\circ}C$) for 2, 4, or 6 hours. After treatment, the NDVI (Normalized Difference Vegetation Index) values of tomato transplants treated at 25 and $40^{\circ}C$ were lower than that at $10^{\circ}C$. The root fresh weight was lowest at $40^{\circ}C$. After transplanting, the transplants that were exposed to the air temperature of $40^{\circ}C$ exhibited chlorosis and blight on lower leaves. The degree of damage on leaves was severer as the high temperature exposure time was longer. The temperature conditions during the transportation also influenced the growth, flowering and fruit set of tomatoes after transplanting. The fruit number and weight of first truss was lowest at $40^{\circ}C$ for 6 hours. Accordingly, it is recommended that the temperature during the transportation should be controlled and kept at the range from 10 to $25^{\circ}C$ even though the period is short (within as six hours) in order to maintain the quality of transplants.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.65-76
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• 2006

Scz1, an isolate of Sclerotinia homoeocarpa, was recently reported as a novel pathogen responsible for dollar spot disease in Zoysiagrass, a warm season turfgrass. Scz1 possessed different characteristics on mycelial pigment, mycelial affinity and host pathogenecity compared to those of Scb1, a typical isolate, obtained from creeping bentgrass, a cool season turfgrass. In this study, only three isolates, Scz1, Scz2(another analogous isolate of Sclerotinia homoeocarpa from zoysiagrass), and Scb1, were examined at the molecular level using the internal transcribed spacer(ITS) and random amplified polymorphic DNA(RAPD) assays to verify their identification and genetic variation. As a result of ITS assay, partial ITS sequences of three isolates showed 94-97% similarity with a standardized ITS sequence of S. homoeocarpa registered on BLAST. In the analysis of RAPD, range value through similarity matrix was 0.167 between Scz1 and Scb1, 0.139 between Scz2 and Scb1, and 0.713 between Scz1 and Scz2, respectively. Furthermore, tendegram analysis indicated that Scz1 and Scz2, unlike Scb1, were clustered together as accompanying a high genetic similarity. In in vitro fungicide bioassay, $EC_{50}$ value representing the sensitivity degree to propiconazole, a well-known fungicide for dollar spot disease, was 0.012 ${\mu}g/ml$ for Sczl, 0.003 ${\mu}g/ml$ for Scz2, and 0.030 ${\mu}g/ml$ for Scb1. From all data taken, we concluded that both Scz1 and Scz2 belonged to one group of S. homoeocarpa, since they exhibit the same host range and high level of genetic similarity, whereas their chemical competences to a fungicide were different. This study would provide further approach for assessing genetic diversity of S. homoeocarpa isolates as well as characterizing individual isolate against chemical exposure.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.3
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• pp.196-204
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• 2018

The main objective of this study was to identify the best quality rice for cultivation on reclaimed land in Jeollabukdo-Province based on yield, head rice ratio, protein content, amylose content, and Toyo taste value evaluations. Seven varieties of rice were grown for two years on the reclaimed land. The Sukwang variety had the earliest heading date. The tiller number for the Younghojinmi variety was 19 on average, and its variation in tiller number was the lowest, which showed that the safety for cultivation of the variety was high on the reclaimed land with respect to that of the other varieties. The culm and panicle lengths of the Sukwang and Hyunpum varieties were the highest at 81.8 and 21.3 cm, respectively. Shindongjin produced the highest thousand grain weight at 27.7 g, whereas Haepum produced the lowest at 22.3 g. The number of grains per panicle for 7 all varieties was statistically equal for both years. The yield order for the varieties was Shindongjin (590) > Hopum (575) > Younghojinmi (552) > Sukwang (551) > Hopum (543) > Mipum (534) > Haepum (498 kg/10a), which showed that there was no significant difference in average yield between the varieties when both years are taken into consideration. However, the annual difference in Haepum yield between 2015 and 2016 was the highest at 108 kg/10a, indicating low cultivation safety. The head rice ratio of Younghojinmi was higher than for the other cultivars in both 2015 and 2016. However, there was no significant difference between the 2 years when the averages for all varieties were analyzed. There was was a considerable difference in protein and amylose content between the varieties in the two years, although this was not apparent in the results when the average over 2 years for each variety was calculated. There was no significant difference between the two years with respect to the average head rice ratio, and the protein and amylose contents of the seven varieties. The Toyo taste values for the Sukwang and Mipum varieties were higher than for the other varieties. Based on the principle characteristics, such as Toyo value, the Sukwang variety is a suitable substitute for Shindongjin, which has been previously used to produce high-quality rice on the reclaimed land.

• Research in Plant Disease
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• v.10 no.2
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• pp.100-104
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• 2004

Two species of Phytophthora were isolated from a leaf blight disease found on castor bean plants growing at a residential area of Hwanggeum-dong in Daegu city. One species was producing conspicuously papillate, noncaducous, ovoid to obpyriform sporangia, 31.2-58.5 ${\times}$ 25.4-44.1 ${\mu}{\textrm}{m}$ in range with an average of 46.4 $\pm$ 6.5 ${\times}$ 35.9 $\pm$ 4.7 ${\mu}{\textrm}{m}$ on simple sympodial sporangiophores, was heterothallic with oogonia globose, 22.5-35.0 ${\mu}{\textrm}{m}$ with an average of 30 $\pm$ 3.3 ${\mu}{\textrm}{m}$ in diameter, oospores plerotic, 18.8-30.0 ${\mu}{\textrm}{m}$ in range averaging 25.4 $\pm$ 2.8 ${\mu}{\textrm}{m}$, and with antheridia amphigynous. This species was identified as P. nicotianae Breda de Haan. The other species produced papillate, caducous, ovoid to ellipsoid sporangia with pedicel, 21.5-54.6 ${\times}$ 17.6-34.3 ${\mu}{\textrm}{m}$ in range with an average of 41.7 $\pm$ 7.1 ${\times}$ 28.4 $\pm$ 4.0 ${\mu}{\textrm}{m}$, and was heterothallic with oogonia globose, 21.3-26.8 ${\mu}{\textrm}{m}$ with an average of 23.0 $\pm$ 1.6 ${\mu}{\textrm}{m}$ in diameter, oospores plerotic, 17.5-23.8 ${\mu}{\textrm}{m}$ in range averaging 20.2 $\pm$ 1.8 ${\mu}{\textrm}{m}$, and with antheridia amphigynous. This species was identified as P. palmivora (Butler) Butler. Both species produced chlamydospores. Pathogenicity of the 2 speices was confirmed by foliar inoculation of castor bean seedlings. Both species have been reported to infect castor bean plants in a few foreign countries but it is the first that a disease of castor bean plants caused by either or both of the species was found in Korea.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.98-106
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• 2012

This research has been carried out to find out the highest effect on insecticidal, fungicidal and herbicidal activities in leaves, stem and tuber extracts of yacon (Smallanthus sonchifolius) and extraction methods such as water, boiling water and methanol. Characteristics of potential herbicidal components among extraction methods were investigated by solvent fractions such as hexane, chloroform, ethyl acetate, butanol, and water. Generally, methanol extract was the best on inhibition of germination rate, plant height, and root length in cucumber and barley. On the other hand, the inhibition effect on growth in cucumber and barley was the best in tuber among plant parts of yacon. Inhibition of germination rate, plant height, and root length in cucumber and barley in solvent fractions was the best in water fraction, but there were no differences in other fractions. Digitaria sanguinalis L. and Solanum nigrum L. by 5 and 10% extractions of yacon tuber were controlled by more than 70~80% and 95~100%, respectively. However, there was no inhibition effect on foliar treatment in cucumber and barley as affected by 5 and 10% extractions of yacon tuber. Mortality of green peach aphid (Myzus persicae Sulzer) was 50% at 3 days after treatment of 5% extracts of yacon leaves. Mortality of brown plant hopper (Nilaparvata lugens Stal) was only 24% in 5% extracts of stems and leaves with midrib, but was 57% in 5% extracts of leaves without midrib. There was no fungicidal effect on anthracnose (Colletotrichum truncatum), wilt disease (Fusarium oxysporum), verticillium wilt (Verticillium dahliae), bacterial blight (Xanthomonus oryzae) in 5% extracts of yacon leaves.

• Sleep Medicine and Psychophysiology
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• v.13 no.1
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• pp.27-32
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• 2006

Objectives: Nasal continuous positive airway pressure (nCPAP) is the treatment of choice and has been shown to reduce the frequency of nocturnal respiratory events, improve sleep architecture, and decrease daytime sleepiness in patients with obstructive sleep apnea syndrome (OSAS). However, little is known about the compliance of nCPAP treatment in Korea. Our objective was to look into the nCPAP compliance and examine the factors influencing it. Methods: We reviewed the records of one hundred and twenty consecutive patients with OSAS referred for nocturnal polysomnography with nCPAP pressure titration during the period of January 1995 through April 1999 to the Seoul National University Hospital. We performed a telephone interview and obtained data from eighty-three patients. Results: In sixty patients who had accepted nCPAP treatment, twenty-six patients (43.3%) were still using nCPAP device, while thirty-four patients (56.7%) stopped using it. Fifteen patients (25%) were using nCPAP device everyday. In thirty-four patients who discontinued nCPAP use, twenty-five patients (73.5%) did within the first three months, and thirty-one (91.2%) within the first year. Significant predictor of long-term nCPAP use was the presence of subjective daytime sleepiness before nCPAP application. Conclusions: Long-term compliance with nCPAP treatment appears to be associated with the presence of subjective daytime sleepiness before nCPAP application. Long-term compliance with nCPAP may be mostly predicted from the usage pattern within the first three months of use.