• Mycobiology
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• v.46 no.3
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• pp.287-295
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• 2018

In this study, we evaluated the effect of different temperatures (10, 20, 30, and $40^{\circ}C$) and relative humidities (RHs; 12, 44, 76, and 98%) on populations of predominant grain fungi (Aspergillus candidus, Aspergillus flavus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum) and the biocontrol activity of Pseudomonas protegens AS15 against aflatoxigenic A. flavus KCCM 60330 in stored rice. Populations of all the tested fungi in inoculated rice grains were significantly enhanced by both increased temperature and RH. Multiple linear regression analysis revealed that one unit increase of temperature resulted in greater effects than that of RH on fungal populations. When rice grains were treated with P. protegens AS15 prior to inoculation with A. flavus KCCM 60330, fungal populations and aflatoxin production in the inoculated grains were significantly reduced compared with the grains untreated with strain AS15 regardless of temperature and RH (except 12% RH for fungal population). In addition, bacterial populations in grains were significantly enhanced with increasing temperature and RH, regardless of bacterial treatment. Higher bacterial populations were detected in biocontrol strain-treated grains than in untreated control grains. To our knowledge, this is the first report showing consistent biocontrol activity of P. protegens against A. flavus population and aflatoxin production in stored rice grains under various environmental conditions of temperature and RH.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.207-212
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• 1998

Tea field-collected populations of the tea red spider mite (Tetranychus kazawai Kishida) from five different locations in the southern region of Korea were assessed for resistance to seven acaricides using leaf spray method. There were considerable differences in susceptibility depending on the tested acaricides and the location from which the population was collected. The populations showing high resistance ratio of more than 20 with respect to certain acaricide were as follows: the Sungjun and Cheju populations to azocyclotin, tebufenpyrad, fenpyroximate, pyridaben, propargite, and fenpropathrin; the Haenam population to propargite and fenpyroximate; the Bosung population to propargite; the Youngam population to pyridaben. Therefore, the use of other alternative acaricides against the Sungjun and Cheju populations is needed. However, careful selection of the appropriate acaricide against the Haenam, Bosung and Youngam populations of the tea red spider mite might be maintained in effective control.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.805-810
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• 2007

Inter simple sequence repeat (ISSR) markers were performed in order to analyse the phylogenetic relationships of eight Hypericum electum populations in Korea. The six primers were produced 37 reproducible ISSR bands. Analysis of ISSR from individual plants of Korean H. erectum resulted in 22 polymorphic bands with 59.5%. Across populations, the mean number of alleles per locus was 1.348 and Shannon's information index was 0.203.Population Mt. Gyeryong had the highest expected genetic diversity (0.175) among all populations. When species were grouped by eight populations, within group diversity was 0.140 (Hs), while among group diversity was 0.472 (G$_{ST}$) on a per locus basis. The estimated gene flow (Nm) for H. erectum was very low (0.561). It is suggested that reproductive isolation by the isolation of geographical distance among H. electum populations and genetic drift may have played roles in shaping the population structure of this species. In phonetic tree, all populations were well separated from each other. Thus, ISSR markers are very effective in classifying natural population levels of genus Hypericum in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.167-179
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• 2018

Objective: The aim of this study was to create a set of microsatellite markers with high polymorphism for the genetic monitoring and genetic structure analysis of local goose populations. Methods: Novel microsatellite markers were isolated from the genomic DNA of white Roman geese using short tandem repeated probes. The DNA segments, including short tandem repeats, were tested for their variability among four populations of geese from the Changhua Animal Propagation Station (CAPS). The selected microsatellite markers could then be used to monitor genetic variability and study the genetic structures of geese from local geese farms. Results: 14 novel microsatellite loci were isolated. In addition to seven known loci, two multiplex sets were constructed for the detection of genetic variations in geese populations. The average of allele number, the effective number of alleles, the observed heterozygosity, the expected heterozygosity, and the polymorphism information content were 11.09, 5.145, 0.499, 0.745, and 0.705, respectively. The results of analysis of molecular variance and principal component analysis indicated a contracting white Roman cluster and a spreading Chinese cluster. In white Roman populations, the CAPS populations were depleted to roughly two clusters when K was set equal to 6 in the Bayesian cluster analysis. The founders of private farm populations had a similar genetic structure. Among the Chinese geese populations, the CAPS populations and private populations represented different clads of the phylogenetic tree and individuals from the private populations had uneven genetic characteristics according to various analyses. Conclusion: Based on this study's analyses, we suggest that the CAPS should institute a proper breeding strategy for white Roman geese to avoid further clustering. In addition, for preservation and stable quality, the Chinese geese in the CAPS and the aforementioned proper breeding scheme should be introduced to geese breeders.

• Journal of Life Science
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• v.32 no.8
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• pp.595-600
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• 2022

Water dropworts, Oenanthe javanica and O. javanica var. japonica are called "minari" in Korea and are eaten as a vegetable. Cicuta virosa is common European water hemlock and has toxic properties, such as cicutoxin. Molecular variations of water dropwort species in Korea were investigated using random amplified polymorphic DNA (RAPD). The six populations were studied with 10 primers (Operon, OPB) for RAPD analysis. The 72 DNA fragments (bands) were found among six populations. Among these 72 bands, 61 (84.7%) bands were polymorphic. The typical populations of Cicuta virosa in Korea were small, isolated, and patchily distributed for natural populations and they maintained a high level of genetic diversity. However, when cultivated populations of O. javanica var. japonica were large and widely grown in rice paddies as vegetables, they maintained a lower genetic diversity than those of C. virosa and wild populations of O. javanica. Although the diversity indices of wild populations were shown to be higher than those of cultivated populations, no significant difference for measures of genetic variability was shown. Total genetic diversity value (H_T) was 0.342. The interlocus variation in the within-population genetic diversity (H_S) was 0.201. The proportion of total genetic variation due to differences among populations (G_ST) range was 0.414, indicating that 41.4% of the total variation was among populations. In conclusion, the RAPD technique was a useful method for discrimination between C. virosa and O. javanica. In addition, RAPD-OPB markers could further distinguish the strains from different food sources.

• Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.98-104
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• 1999

The characteristics of the populations of shortnecked clam (Ruditapes philipinarum) originated from three different seed-production sites, Hadong, Kochang and Ulsan along the coast of Korea, were analysed by the morphological differences and the random amplified polymorphic DNA (RAPD) profiles. The morphology of the shell and survival rate for each population were also investigated 13-months after transplantation to a farming site in Shinsung. The morphology of the populations from Hadong and Kochang showed significant differences (P<0.05), but one year after transplantation to Shinsung, the morphology of these three populations was no longer significantly different (P>0.05). The template DNA for RAPD was efficiently extracted from the digestive diverticula of the clams. Up to 13 of amplified fragments were detected using arbitrary primers. Within the species of R. philipinarum, the genetic similarities ranged from 0.196 to 0.259. The populations from Hadong and Ulsan showed the highest similarity. The survival rates of the populations from Hadong $(69.4\%)$ and Ulsan $(63.8\%)$ were higher than that from Kochang $(41.7\%)$ 13-months after transplantation. From the RAPD analysis, it could be used as one of the primary criterion in determining which shellfish populations among various seed-production sites tend to be genetically similar and more adaptable and transplantable to a farming site.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.946-951
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• 2003

The Genetic diversity and relationship of native Siri (Bos indicus) cattle populations of Bhutan were evaluated using 20 microsatellite markers. A total of 120 Siri cattle were sampled and were grouped into four populations according to their geographical locations which were named Siri West, Siri South, Siri Central and Siri East cattle. For each, 30 individuals were sampled. In addition, 30 samples each of Indian Jaba (B. indicus), Tibetan Goleng (B. taurus), Nepal Hill cattle (B. indicus), Holstein Friesian (B.taurus) and Mithun (B. frontalis) were typed. The mean number of alleles per loci (MNA) and observed heterozygosity (Ho) were high in the Siri populations ($MNA=7.2{\pm}0.3$ to $8.9{\pm}0.5$ and $Ho=0.67{\pm}0.04$ to $0.73{\pm}0.03$). The smallest coefficient of genetic differentiation and genetic distance ($F_{ST}=0.015$ and $D_A=0.073$) were obtained between Siri West and Siri Central populations. Siri East population is genetically distinct from the other Siri populations being close to the Indian Jaba ($F_{ST}=0.024$ and $D_A=0.084$). A high bootstrap value of 96% supported the close relationship of Siri South, Siri Central and Siri West, while the relationship between Siri East and Jaba was also supported by a high bootstrap value (82%). Data from principal component analysis and individual assignment test were in concordance with the inference from genetic distance and differentiation. In conclusion we identified two separate Siri cattle populations in Bhutan at the genetic level. One population included Siri cattle sampled from the West, Central and South of the country and the other Siri cattle was sampled from the East of the country. We suggest that Siri cattle conservation program in Bhutan should focus on the former population as it has received less genetic influence from other cattle breeds.

• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.80-86
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• 2002

The activities against Frankliniella occidentalis adults collected at rose greenhouse of 40 commerical insecticides were investigated. Among them 9 insecticides showed over 80% mortality to the adults; chlorfenapyr, chlorpyrifos- methyl, emamectin benzoate, fenthion, fipronil, phenthoate, spinosad, chlorpyrifos+diflubenzuron and furathiocarb+diflubenzuron. Susceptibility of field populations collected from greenhouse rose at 5 locations in 2001 was evaluated against the 9 insecticides selected. There was considerable difference in susceptibility depending on the treated insecticides and the regions from which the populations were collected. Goyang and Gimhae populations showed lower $LC_{50}$(ppm) values then Imsil, Jincheon and Gaangjin populations to all the tested insecticides. The adults of all field populations showed lower $LC_{50}$ values less than 1 ppm to emamectin benzoate, fipronil and spinosad. From these results, we could recommend 5 insecticides, such as emamectin benzoate, fipronil, spinosad, chlorpyrifos+diflubenzuron and furathiocarb+diflubenzuron as effective ones to control the Frankliniella occidentalis field populations.

• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.203-207
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• 1987

Studies were conducted to investigate the race distribution of soybean cyst nematode (Heterodera glycines Ichinohe) in Korea. The results are abstracted as follows. The soybean cyst nematode populations collected from Kangwon Province were identified as races 1 and 3; the nematode populations collected from Kyunggi Province were identified as race 3, 5 and c and those collected from Chungnam Province were identified as races 1 and 5. From the total 21 populations 11 populations or 52.4% of the total were race 1; 6 populations or 28.6% of the total were race 5; 3 populations or 14.3% of the total were race 3 and one population or 4.8% of the total were race c. Soybean cyst nematode populations from the same district, at least from the same 'myeon' district were identified as same race. Of these 4, race 3 has not been recorded in Korea yet.

• Journal of Aquaculture
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• v.17 no.1
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• pp.12-23
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• 2004

Genomic DNAs were extracted from the muscle of twenty-two specimens of two shortnecked clam, Ruditapes phifippinarum populations collected in Anmyeondo and Seocheon. Genetic differences within and between populations were analysed by random amplified polymorphic DNAs-polymerase chain reaction (RAPD-PCR) using twenty arbitrary decamer primers. Out of 20 primers, 6 generated a total of 1,111 major and minor RAPD bands from individuals of two sites, producing approximately 4.2 average polymorphic bands per primer in individuals from Anmyeondo and ranging in size from less than 50 to larger than 1,500 base pairs (bp). The electrophoretic analysis of RAPD products amplified showed moderate levels of similarity among the different individuals in Seo-cheon population. The average bandsharing values (BS value) of the samples within population from Anmyeondo ranged from 0.155 to 0.684, whereas it was 0.143∼0.782 within population from Seocheon. The average BS value between individuals No. 13 and No. 14 from Seocheon was 0.782 which was higher than that of those from Anmyeondo. The single linkage dendrogram resulted from three primers (OPA-08, -09 and -20), indicating six genetic groupings composed of group 1 (No.4, 8 and 10), group 2 (No. 18), group 3 (No.2, 5 and 7), group 4 (No. 1, 3, 6, 9, 11, 12, 13, 14, 15 and 17), group 5 (16, 19 and 20) and group 6 (No. 21 and 22). In the Seocheon population, the individual No. 18 clustered distinctly from the others of this population. The observed genetic distance between the two populations from Anmyeondo and Seocheon was more than 0.209 (0.247 and 0.275). The shortest genetic distance (0.094) displaying significant molecular differences was between individuals No. 13 and No. 14. Especially, the genetic distance between individuals No. 22 and the remnants among individuals in two geographical populations was highest (0.275). This result illustrated that individual No.22 is distinct from other individuals within two shortnecked populations. The different geographical features of two sites may have caused the genetic diversity in two shortnecked clam populations.