• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.615-622
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• 2013

The purpose of this study was to evaluate microbial contamination of melons in Korea. A total of 123 samples including melon fruits, leaves, seeds, soils, and irrigation water were collected from farms and markets to detect total aerobic bacteria, coliform, Escherichia coli, and pathogenic bacteria such as Bacillus cereus, Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus. Samples were collected from Iksan and Nonsan farms to monitor bacterial levels on pre-market melons. The total aerobic and coliform bacteria on melon cultivation were between 0.43 and 6.65 log CFU $g^{-1}$, and 0.67 and 2.91 log CFU $g^{-1}$, respectively. Bacillus cereus, a fecal coliform, was detected in soils and melon leaves from Iksan farm at 2.95, 0.73 log CFU $g^{-1}$, respectively, and in soils from Nonsan farm at 3.16 log CFU $g^{-1}$. Market melon samples were collected to assay bacterial load on melon being sold to consumers. The contamination levels of total aerobic bacteria in agricultural markets, big-box retailers, and traditional markets were 4.82, 3.94, 3.99 log CFU $g^{-1}$, respectively. The numbers of coliform in melon on the markets ranged from 0.09 to 0.49 log CFU $g^{-1}$. Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus were not detected in any samples. The count of total aerobic bacteria on melon seeds ranged from 0.33 to 3.34 log CFU $g^{-1}$. This study found that irrigation water, soil, manure and various farm work activities including post-harvest processes were latent sources of microbial contamination. These results suggest that hygienic management and monitoring of soil, water, and agricultural material should be performed to reduce microbial contamination in melon production.

• Journal of Life Science
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• v.22 no.1
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• pp.31-35
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• 2012

In a previous study, succinate dehydrogenase (SDH) and triose phosphate isomerase (TPI) were detected by 2D gel electrophoresis as differentially expressed proteins in the longissimus thoracis muscles of cattle aged between 12 and 27 months old. In the present study, we investigated the association of SDH and TPI gene expression with intramuscular fat content in 50 Hanwoo steers. The SDH gene was expressed at a 4 times higher level in the 12 month old group than in the 27 month old group (p<0.01). A regression analysis between gene expression value and intramuscular fat content showed a negative correlation between expression of the SDH gene and intramuscular fat content (p<0.001). In contrast, the expression of the TPI gene showed no significant association with intramuscular fat content. This result suggests that the SDH gene may be a candidate marker gene for intramuscular fat content in the longissimus thoracis of Korean cattle.

• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.45-51
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• 2012

BACKGROUND: This study was carried out to establish pre-harvest residue limit of fungicides pyrimethanil and trifloxystrobin in persimmon, based on dissipation and biological half-lives of two fungicides residue. METHODS AND RESULTS: Both pyrimethanil and trifloxystrobin were extracted with acetonitrile, clean-up with $NH_2$ SPE cartridge and residue were analyzed by HPLC/DAD. Limit of Detection was 0.01 mg/kg. Average recovery were $81{\pm}1.62%$, $98{\pm}1.58%$ of pyrimethanil, and $91{\pm}2.94%$, $98{\pm}1.25%$ of trifloxystrobin at fortification levels at 0.1 and 0.5 mg/kg, respectively. CONCLUSION: The biological half-lives of pyrimethanil were 15.6 and 11.6 days at sprayed with recommended and double dosage, respectively. The biological half-lives of trifloxystrobin were 10.4 and 10.3 days at sprayed with recommended and double dosage, respectively. The pre-harvest residue limit of pyrimethanil and trifloxystrobin were recommended as 2.69 and 0.83 mg/kg for 10 days before harvest, respectively.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.238-243
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• 2004

To investigate the changes in content of residual pesticides for safety production of young radishes in the production steps in greenhouse and to evaluate the safety of young radishes in the final consuming step, biological half-life of pesticides (diazinon, endosulfan) in packaging products was studied. Samples were collected regularly from 2 hours to 10 days after the distribution of pesticides in young radishes. The contents of residual pesticides in young radishes during cultivating in greenhouse as the levels of distribution concentrations reduced with time. During 10 days of pesticides distribution, decomposition rate of pesticides were diazinon > endosulfan. A half-life of endosulfan was 0.6 day longer than diazinon because endosulfan derived persistent endosulfan sulfate. To produce the safe young radish, after the distribution of the pesticides the desirable harvest time based on maximum residue limit (MRL) was 6th day diazinon for and 10th day for endosulfan.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.98-107
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• 2017

A DNA profile database was constructed to investigate the genetic relatedness of 72 germplasm samples of Pyrus and related cultivars using microsatellite markers. Three P. pyrifolia, four P. commus, and one P. betulifolia cultivars with different morphological traits were screened using 387 pairs of microsatellite primers. A core set of 11 primer pairs was selected to obtain 133 polymorphic amplified fragments meeting three criteria: high polymorphism information contents (PIC), high repeatability, and distinct allele patterns. The number of alleles per locus ranged between 4 and 22. Average PIC was 0.743 (range: 0.557 - 0.879). Cluster analysis using the unweighted pair - group method with arithmetical average (UPGMA) separated the 72 pear cultivars and germplasm samples into four major groups: Chinese, European pears, and a cluster of 55 Asian pears that could be reclassify into two subcluster, I - $1^{st}$ and II - $2^{nd}$, according to pedigree information. Almost all of the cultivars were discriminated by 11 microsatellite marker genotypes. The microsatellite DNA profile database may be utilized as tool to verify distinctness, uniformity, and stability between candidate cultivar, and to verify in the distinctness of existing cultivars.

• Korean Journal of Medicinal Crop Science
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• v.21 no.5
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• pp.353-360
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• 2013

Korean ginseng (P. ginseng C. A. Meyer) is one of the most important medicinal plant in the world. Understanding genetic variability among the assortment of Korean ginseng is important for breeding. The aim of this study was to molecularly characterize Korean ginseng cultivar and breeding lines through the use of eight previously reported STS markers (MFGp183, MFGp130, MFGp110, UFGp74, UFGp163, MFGp108, MFGp81 and UFGp156). All STS markers produced interpretable electropherograms from 31 accessions consisting of 11 Korean ginseng cultivars and 20 breeding lines. When eight STS markers were combined, we identified to total 19 genetic patterns; in particular, nine cultivars (Chunpoong, Yunpoong, Gopoong, Gumpoong, Sunpoong, Sunone, Cheongseon, Sunhyang, Cheonryang) and 5 breeding lines (G08012, G04079, G04075, G08036, G04110) in ginseng samples can be discriminated from the others. Together with other available markers, these STS markers will contribute to the management of ginseng genetic resources and the protection of breeders' rights.

• Korean Journal of Medicinal Crop Science
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• v.21 no.2
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• pp.91-96
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• 2013

This study describes the identification of Panax species using mitochondrial consensus primers. Initially, a total of thirty primers were tested in ten Korean ginseng cultivars and two foreign Panax species, P. quinquefolius and P. notoginseng. In the polymerase chain reaction (PCR) amplification results, three primers (cox1, nad1/2-3 and nad2/1-2) generated co-dominant polymorphic banding patterns discriminating Korean ginseng cultivars from P. quinquefolius and P. notoginseng. However, these primers could not generated polymorphisms among the Korean ginseng cultivars, and simply represented species-specific polymorphisms for P. quinquefolius and P. notoginseng. Primers PQ91 and PN418 were designed from the consensus sequence of nad1/2-3 region. Two banding patterns (A or B) were detected in PQ91. Korean ginseng cultivars and P. notoginseng shared the same banding pattern (A type) and P. quinquefolius was identified another banding pattern (B type). In the case of PN418, two banding patterns (A or B) were detected in the Korean ginseng cultivars and two foreign Panax species. Korean ginseng cultivars and P. quinquefolius shared the same banding pattern (A type) and P. notoginseng was identified another banding pattern (B type). The combination banding patterns of three Panax species, Korean ginseng cultivars (Panax ginseng C. A. Mey.), P. quinquefolius and P. notoginseng, was identified as 'AA', 'BA' and 'AB', respectively. Consequently, PQ91 and PN418 primer sets can be used to distinguish among Panax species.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.112-117
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• 2012

In order to improve or replace the direct addition method of nitrite and ascorbic acid, the effect of nitrite and ascorbic acid-derived gas addition on color development and physical characteristics in emulsified sausage was investigated. Nitrite (150 ppm) and ascorbic acid (450 ppm) were added directly to emulsion in the control group, but in the treatment group nitrite and ascorbic acid-derived gas was used for emulsion. In the control and treatment groups, pH values were higher than raw meat, but these values did not show significant change during the storage in both groups. In the meat color, lightness (CIE $L^*$) and redness ($a^*$) values of control and treatment groups were higher compared to raw meat. The treatment group has lower redness and higher yellowness ($b^*$) values than control group during the storage (p<0.05). However, lightness was not significantly different between control and treatment groups. The cook and storage loss values were significantly different between control and treatment groups (p<0.05), but the water holding capacity and shear force values were not significantly different between groups. These results showed that treatment of nitrite and ascorbic acid-derived gas has a similar effect to direct addition of nitrite and ascorbic acid on color development and physical characteristics in emulsified sausage. Also, these results showed that nitrite and ascorbic acid-derived gas addition may be a good possible alternative of nitrite and ascorbic acid using in emulsified sausage.

• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.444-454
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• 2013

The development of random amplified polymorphic DNA (RAPD) and expressed sequence tag-derived simple sequence repeats (EST-SSRs) provided a useful tool for investigating Korean ginseng genetic diversity. In this study, 18 polymorphic markers (7 RAPD and 11 EST-SSR) selected to assess the genetic diversity in 31 ginseng accessions (11 Korean ginseng cultivars and 20 breeding lines). In RAPD analysis, a total of 53 unique polymorphic bands were obtained from ginseng accessions and number of amplicons ranged from 4 to 11 with a mean of 7.5 bands. Pair-wise genetic similarity coefficient (Nei) among all pairs of ginseng accessions varied from 0.01 to 0.32, with a mean of 0.11. On the basis of the resulting data, the 31 ginseng accessions were grouped into six clusters. As a result of EST-SSR analysis, 11 EST-SSR markers detected polymorphisms among the 31 ginseng accessions and revealed 49 alleles with a mean of 4.45 alleles per primer. The polymorphism information content (PIC) value ranged from 0.06 to 0.31, with an average of 0.198. The 31 ginseng accessions were classified into five groups by cluster analysis based on Nei's genetic distances. Consequently, the results of ginseng-specific RAPD and EST-SSR markers may prove useful for the evaluation of genetic diversity and discrimination of Korean ginseng cultivars and breeding lines.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.429-434
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• 2014

This study describes the efficient method for the discrimination of 'Cheonryang' in Panax ginseng Meyer using a STS primer. A total of 208 STS primers were applied to polymerase chain reaction (PCR) amplification for discriminating Korean ginseng cultivars. Co-dominant polymorphic band patterns were generated with two primers, MFGp 0019, MFGp 0248, and successful identification of 'Cheonryang' was achieved from out of 11 Korean ginseng cultivars. Two different sizes of DNA band patterns were detected with MFGp 0019 primer. Ten Korean ginseng cultivars shared the same size of amplified DNAs (389 bp), but 'Cheonryang' showed a different size. Thus 'Cheonryang' can be efficiently distinguished from the other ten ginseng cultivars by using the MFGp 0019 primer. In the case of MFGp 0248, two different sizes of DNA band patterns were detected in the eleven ginseng cultivars. Same sized amplified DNA bands (307 bp) were shown in five cultivars (Chunpoong, Gopoong, Kumpoong, Cheongsun, Sunhyang) and 254 bp sized DNA bands were identified in the other 6 cultivars (Yunpoong, Sunpoong, Sunun, Sunone, Cheonryang, K-1). In conclusion, the two STS primers, MFGp 0019, and MFGp 0248, provide a rapid and reliable method for the specific identification of 'Cheonryang' cultivar from a large number of samples.