• Korean Journal of Ichthyology
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• v.25 no.3
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• pp.149-156
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• 2013

Phylogenetic relationships and DNA polymorphism among local populations of two Korean gobiidae species: Boleophthalmus pectinirostris and Scartelaos gigas were investigated based on 12S and 16S mitochondrial DNA and mitochondrial cytochrome b DNA sequences. DNA polymorphisms of B. pectinirostris between Suncheon and Gunsan populations were 100% identity from 434 bp segment of 12S rRNA gene and from 444 bp segment of mitochondrial cytochrome b genes, and 99.6% (2 bp different) identity from 484 bp segments of 16S rRNA genes. These results indicated the long period of geographic isolation between two populations of B. pectinirostris in Korea caused such high degrees of DNA polymorphisms. Based on the phylogenetic tree constructed from the two gobiid species in Korea, two genetically distinct groups of B. pectinirostris and S. gigas groups were recognized.

• Korean Journal of Plant Resources
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• v.17 no.3
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• pp.304-313
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• 2004

This study was conducted to find out the scientific maize breeding protocol for developing high performing single cross hybrid using introduced U.S. elite inbred lines; the pattern of inheritance, heterosis and heritabilities of six agronomic traits were studied in the progenies derived from five crosses (Mo17/B14A, Va85/B73, C103/ND203, FR35/Oh43, Wf9/A632). Among the five cross combinations, the cross combination of Mo17/B14A showed the highest heterosis for the most agronomic traits. Among 6 agronomic traits, the grain yield showed the highest heterosis effect in most cross combinations. Most of the agronomic traits in this study showed more than 50% heritability for six cross combinations, with an exception of the ear length trait. In conclusion, since Mo17/B14A showed excellent performance for most of the agronomic traits, these inbred lines were desirable combination and regarded as superior germ plasm sources for F1 hybrid development. The results of current studies will be utilized for developing high performing single cross hybrid from maize inbred lines, and will be used for the further genetic analysis of agronomic traits and maize breeding programs.

• Korean Journal of Plant Resources
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• v.31 no.5
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• pp.498-514
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• 2018

A statistical analysis for 3651 genetic resources collected from China (1,542), Japan (1,409), Korea (413), and India (287) was conducted using normal distribution, variability index value (VIV), analysis of variation (ANOVA) and Ducan's multiple range test (DMRT) based on a data obtained from NIRS analysis. In normal distribution, the average protein content was 8.0%, whereas waxy type amylose and common rice amylose were found to be 8.7% and 22.7%, respectively. The protein contents ranged from 5.4 to 10.6% at the level of 95%. The waxy amylose and common rice amylose ranged from 5.9 to 11.5%, and from 16.9 to 28.5% at 95% confidence level, respectively. The VIV was 0.59 for protein, 0.64 for low amylose, and 0.81 for high amylose contents. The average amylose contents were 18.85% in Japanese, 19.99% in Korean, 20.27% in Chinese, and 25.46% in Indian resources, while the average protein contents were found to be 7.23% in Korean, 7.73% in Japanese, 8.01% in Chinese, and 8.17% in Indian resources. The ANOVA of amylose and protein content showed significant differences at the level of 0.01. The F-test for amylose content was 158.34, and for protein content 53.95 compared to critical value 3.78. The DMRT of amylose and protein content showed significant difference (p<0.01) between resources of different countries. Japanese resources had the lowest level of amylose contents, whereas, the lowest level of protein content was found in Korean resources compared to other origins. Indian resources showed the highest level of amylose and protein contents. It is recommended these results should be helpful to future breeding experiments.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.83-92
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• 2017

The purpose of this study was to estimate the inbreeding level and effective population size of Korean indigenous chickens. In the study, two variables were considered to evaluate the pedigree completeness: (1) the proportion (%) of animals with complete pedigree, and (2) the proportion of animals with inbreeding coefficients greater than zero. In the proportion of animals having complete pedigree, all strains reached almost 100% completeness in 1~2 years. In the proportion of animals with inbreeding coefficients greater than zero, all strains reached almost 100% completeness in 5~6 years. We considered that the pedigree recoding system is well managed and that the inbreeding coefficient is a reliable measure. Over the past 20 years, the increase of inbreeding coefficients in Korean indigenous chicken strains has been 7.6~10.9%. The S strain showed the most rapid increase of inbreeding coefficient of 8.2% in 10 years. The reason for this rapid increase is considered to be associated with the fact that the numbers of sires and dams involved in reproduction was 115 and 91, respectively, which are lower than those of the other strains. According to average rates of increase in inbreeding coefficients (${\Delta}F$), all strains have ${\Delta}F$ values of 0.39~0.85%, which is lower than 1%, and the effective population size is above 50. The results showed that inbreeding levels were within the acceptable range and that Korean indigenous chicken population scan be regarded as safe from the threat of extinction.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.234-244
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• 2013

This study was conducted to determine the factors affecting to seed characteristics and seedling growth of Zelkova serrata. The seeds were collected from sixteen populations of Z. serrata and the seed characteristics (i.e., seed length, width, weight and full seed rate) were measured. We also measured the 1-year-old seedling growth of each population at nursery. All seed characteristics showed significant differences in population level. Seed length and seed width were positively correlated with latitude, longitude, altitude and distance from coast line of sampling site. Seed length and seed width also negatively correlated with annual mean temperature, mean temperature of growing season (Mar.~Oct.). The ratio of seed length/seed width showed inverse trend in case of seed length and seed width. Seed weight/1,000 grains had no correlation with geographic factors but showed negative correlation with annual mean dryness index. Seed weight/L showed negative correlation with latitude and longitude and positive correlation with mean temperature of growing season of sampling site. Full seed rate showed negative correlation with latitude, longitude and annual mean dryness index of sampling site. There were significant differences among populations, among family within population and among individuals within family in seedling growth. Height and diameter of root collar of seedling showed negative correlation with longitude and mean humidity of growing season of sampling site. Height growth of seedlings was not correlated with any seed characteristics but, diameter at root collar showed low negative correlation with seed weight/1,000 grains and seed weight/L. We discussed the implications of the results in view of tree improvement of Z. serrata.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.40-45
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• 2000

Rhizoctonia solani Kuhn[Thanatephorus cucumeris (Frank) Donk]is a destrutive soil-borne plant pathogen affecting many agricultural crops worldwide. R. solani is divided into anastomosis groups based on the ability of the hyphae to fuse, and into subgroups based on morphological, physiological characteristics. AG classifications are convenient and useful in identifying primary causal agents of Rhizoctonia diseases, although the mechanism of anastomosis is not fully understood. Beacause of the difficulties, we sought to develop a more direct method for genetic identification and charaterization of R. solani. Twenty nine isolates of R. solani were used for the analysis of genetic relationships among themselves and for rapid anastomosis grouping with AFLP method. All isolates studied were divided into five groups. Isolate 6 was included in AG-3 with 67% genetic similarity. When isolates 3 was compared with 13 and 10 each, they showed more than 84% and 83% similarity, respectively. Isolates 3, 4, 5, 13, and 16 were included in AG-1 with 83% genetic similarity. Isolates 1, 7, and 8 were included in AG-1(IB).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.386-391
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• 1988

Five barley crosses and their progenies (F$_2$, F$_3$, and F$_4$) were evaluated the potentiality of hybrid populations to segregate superior yielders in later generation. Four characters used for evaluation were number of spike, number of grain, spike weight and grain weight per plant. Superiority value (Y) of number of spike was best in SB76588${\times}$SB72648 and average of superior plants in F$_4$, was excellent in this cross. Milyang 6${\times}$Suwon 203 showed high Y value and average of F$_4$ superior plants in the number of grain. Spike weight showed the highest Y value and excellent averages of superior plant in Milyang 6${\times}$Suwon 203. Superiority value of grain weight per plant coincided with average of F$_4$ superior plants in 3 crosses and SB76588${\times}$SB72648 was the best among the crosses.

• The Korean Journal of Zoology
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• v.16 no.1
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• pp.67-77
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• 1973

The alcohol dehydrogenase (ADH) isozyme of the four strains of Drosophila melanogaster in Korea was studied by the starch gel electrophoresis and the results are given below: 1. The numbers of bands, staining intensity and mobility are considerably variable in the three strains, Chunchun, Jinju and Sinchon-Seoul, but relatively uniform in the Taijun strain. 2. It is suggested that the Taijun strain may be homogeneous and the other three strains, on the contrary, heterogeneous for the ADH constitution. 3. The electrophoretic patterns are observed to be different between males and females in all strains used which is hard to intereret. 4. The starch gel electrophoresis is to have a resolving power superior to cellulose acetate electrophoresis.

• Korean Journal of Ichthyology
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• v.9 no.2
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• pp.195-201
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• 1997

Environmental sex determination by temperature was revealed in different genotypes (putative XX : XY=1 : 1, 1 : 0, 0 : 1) of nile tilapia (Oreochromis nitoticus). There was no significant deviation from expected sex ratio in control group treated with $27^{\circ}C$, while the temperature regimes of $33^{\circ}C$ and $36^{\circ}C$ during labile period induced the differentiation of phenotypic sex into female with a clear trend forward percent female with increasing temperature. The administration of 240 and/or 480 mg estradiol-$17{\beta}$ ($E_2$)/kg diet also showed the additional effect to derive the phenotypic sex to female in putative XX : XY=1 : 1 and 0 : 1 progeny groups.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.458-464
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• 2010

Twelve garlic cultivars collected from Korea and Mongolia were evaluated genetic similarity and diversity by RAPD method using oligo-nucleotide random primers. Genomic DNA isolated from twelve garlic cultivars were amplified by polymerase chain reaction using 143 primers, and 55 primers showed polymorphic DNA bands. Among a total of 187 bands amplified by 55 primers, 128 polymorphic bands were subjected to analysis for genetic relationship of garlic cultivars. Garlic cultivars were classified into three groups, such as group-I corresponded to Euiseong, Seosan, Samchuk and Yecheon-A, Yechun-B, Euiseong-norang, Jeongsun, Namdo, Yookback and Danyang cultivars, and group-II to Mongolia and group-III to Daeseo cultivars. Thirty DNA bands showing unique specificity to the specific cultivars are likely to be useful for identification of garlic local cultivars as DNA markers.