• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.2
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• pp.59-67
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• 2020

Growth tests on the Wando and Baengnyeongdo cultivars of Saccharina japonica were performed at the Myeongcheon and Gyedo aquafarms, Goheung in Jeollanamdo, from February to July in 2003. Five environmental conditions and 2 traits were measured monthly. The data were used to analyze the growth patterns, relationships between traits and principal component. Box plots were used to display the growth patterns. Scatter plots and regression and correlation coefficients were used to determine the strength of relationships between the traits. A principal component analysis revealed that the first principal component explained more than 91.4% and 90.5% of the total sample variance in the Myeongcheon and Gyedo aquafarms. From the viewpoint of the economic traits (blade length, blade weight), the growth of populations from the Gyedo aquafarm was stronger than that of those from the Myeongcheon aquafarm, and the growth of the Baengnyeongdo cultivar was superior to that of the Wando one.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.235-235
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• 2022

Genome selection is a promising tool for plant and animal breeding, which uses genome-wide molecular marker data to capture large and small effect quantitative trait loci and predict the genetic value of selection candidates. Genomic selection has been shown previously to have higher prediction accuracies than conventional marker-assisted selection (MAS) for quantitative traits. In this study, the prediction accuracy of 10 agricultural traits in the wheat core group with 567 points was compared. We used a cross-validation approach to train and validate prediction accuracy to evaluate the effects of training population size and training model.As for the prediction accuracy according to the model, the prediction accuracy of 0.4 or more was evaluated except for the SVN model among the 6 models (GBLUP, LASSO, BayseA, RKHS, SVN, RF) used in most all traits. For traits such as days to heading and days to maturity, the prediction accuracy was very high, over 0.8. As for the prediction accuracy according to the training group, the prediction accuracy increased as the number of training groups increased in all traits. It was confirmed that the prediction accuracy was different in the training population according to the genetic composition regardless of the number. All training models were verified through 5-fold cross-validation. To verify the prediction ability of the training population of the wheat core collection, we compared the actual phenotype and genomic estimated breeding value using 35 breeding population. In fact, out of 10 individuals with the fastest days to heading, 5 individuals were selected through genomic selection, and 6 individuals were selected through genomic selection out of the 10 individuals with the slowest days to heading. Therefore, we confirmed the possibility of selecting individuals according to traits with only the genotype for a shorter period of time through genomic selection.

• Korean Journal of Plant Resources
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• v.37 no.3
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• pp.270-306
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• 2024

This study investigated the diversity of 323 mung bean accessions from Korea, China, and India, along with six cultivars, using 22 agronomical traits. The standardized Shannon-Weaver index (H') for the qualitative traits ranged from 0.11 (terminal leaflet shape) to 0.98 (pubescence density of pod). Likewise, the coefficient of variation for the quantitative traits ranged from 8.76% (days to maturity (DM)) to 79.91% (lodging rate (LR)), indicating a wide genetic variance. Hypocotyl color, pod color, seed shape, and seed coat surface lust showed different distributions among Korean, Indian, and Chinese accessions. Chinese accessions had the highest average germination rate, DM, days from flowering to maturity, and one-hundred seeds weight, followed by Korean and Indian accessions, while the number of seeds per pod (SPP) displayed the opposite trend, with all except SPP showing significant variation (p < 0.05). Similarly, plant height, days to flowering, and number of pods per plant increased in the order of India > Korea > China, with LR showing the opposite trend (p < 0.05). The mung bean accessions were grouped into four major clusters using hierarchical cluster analysis supported by principal component analyses, and all of the quantitative traits showed significant variations between the clusters (p < 0.05). Generally, the mung bean accessions investigated in this study exhibited wide phenotypic trait variations, which could be beneficial for future genomics studies. Moreover, this study identified 77 accessions that outperformed the controls. Consequently, these superior accessions could provide a wide spectrum of options during the development of improved mung bean varieties.

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.29-29
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• 2015

Clubroot disease is caused by the soil-born obligate plant pathogen Plasmodiophora brassicae. This pathogen can infect all cruciferous vegetables and oil crops, including Brassica rapa, B. oleracea, B. napus, and other Brassica species. Clubroot disease is now considered to be a major problem in Chinese cabbage production in China, Korea, and Japan. We collected several hundreds of P. brassicae infected galls from Korea, and isolated the single spore from the collection. For establishment of novel isolation, and mass-propagation methods for singe spore isolates of P. brassicae pathogen, we developed new filtration method using both cellulose nitrate filter and syringe filter. Accurate detection of P. brassicae pathogen in the field was done by using real-time PCR in the potential infested soil. When we tested the different pathogenicity on commercial Chinese cabbage varieties, P. brassicae from collected galls showed various morphological patterns about clubroot symptom on roots. To date, 8 CR loci have been identified in the B. rapa genome using the quantitative trait loci (QTL) mapping approach, with different resistant sources and isolates. We are trying to develop the molecular marker systems for detect all 8 CR resistant genes. Especially for the study on the interaction between pathogens and CR loci which are not well understood until now, genome wide association studies are doing using the sequenced inbred lines of Chinese cabbage to detect the novel CR genes.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.10
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• pp.1371-1379
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• 2015

Undoubtedly livestock is one of the major contributors to the economy of any country. The economic value of livestock includes meat, dairy products, fiber, fertilizer etc. Understanding and identifying the associations of quantitative trait loci (QTL) with the economically important traits is believed to substantially benefit the livestock industry. The past two decades have seen a flurry of interest in mapping the QTL associated with traits of economic importance on the genome. With the availability of single nucleotide polymorphism chip of various densities it is possible to identify regions, QTL and genes on the genome that explain the association and its effect on the phenotype under consideration. Remarkable advancement has been seen in genome wide association studies (GWAS) since its inception till the present day. In this review we describe the progress and challenges of GWAS in various livestock species.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.199-204
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• 1998

This study was conducted to investigate the chromosomal locations and effects of quantitative trait loci (QTL) associated with chemical properties of rice (Oryza sativa L.). One hundred sixty four recombinant inbred lines (MGRILs) of $F_{11}$ were derived from the cross between Milyang 23, Tongil type, and Gihobyeo, japonica type. They were evaluated for 7 traits of chemical property in rice. Transgressive segregation was observed for all traits examined. Eight significant QTLs were detected (LOD$\geq$2.0) for five traits, including two QTLs for amylose content, two QTLs for potassium content, one QTL for ratio of magnesium to potassium, one QTL for fat content and two QTLs for ash content. Phenotypic variation explained by each QTL ranged from 7.2% to 14.4%. However, no significant QTL was detected for magnesium and protein contents. In amylose content and ash content M alleles originated from Milyang 23 were responsible for increasing these traits and J alleles originated from Gihobyeo also responsible for increasing these traits. Pleiotropic effects of single QTLs on different traits are observed.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.28-32
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• 2012

In the present study, we evaluated the informativeness of SNPs genotyped by the Illumina Bovine SNP50K assay in different cattle breeds. To investigate these on a genome-wide scale, we considered 52,678 SNPs spanning the whole autosomal and X chromosomes in cattle. Our study samples consists of six different cattle breeds. Across the breeds approximately 72 and 6% SNPs were found polymorphic and fixed or close to fix in all the breeds, respectively. The variations in the average minor allele frequency (MAF) were significantly different between the breeds studied. The level of average MAF observed in Hanwoo was significantly lower than the other breeds. Hanwoo breed also displayed the lowest number of polymorphic SNPs across all the chromosomes. More importantly, this study indicated that the Bovine SNP50K assay will have reduced power for genome-wide association studies in Hanwoo as compared to other cattle breeds. Overall, the Bovine SNP50K assay described in this study offer a useful genotyping platform for mapping quantitative trait loci (QTLs) in the cattle breeds. The assay data represent a vast and generally untapped resource to assist the investigation of the complex production traits and the development of marker-assisted selection programs.

• Biomedical Science Letters
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• v.26 no.3
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• pp.238-243
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• 2020

Tuberculosis is a global public health problem and manifests itself as a difference in the genetic susceptibility of the host, along with the properties of Mycobacterium tuberculosis (MTB). The single nucleotide polymorphisms (SNPs) and candidate genes proposed in the Genome-wide association study (GWAS) on tuberculosis in a recently published Chinese population were reported. In this study, we investigated whether the genetic polymorphism of candidate genes related to tuberculosis is reproduced when targeting Koreans. The CLCN6 (rs12404124, rs198391, rs535107), DOK7 (rs1203104, rs1203103) and HLA-DRA (rs1051336) gene polymorphisms showed statistically significant results. In addition, it was also found whether it acts as an expression quantitative trait loci (eQTL) that can influence gene expression. This study confirmed that the genetic polymorphism of the three genes (CLCN6, DOK7, HLA-DRA) affects the development of tuberculosis and will help to understand the genetic specificity of tuberculosis and the interaction between pathogens and hosts.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1378-1385
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• 2002

The importance of direct genetic, maternal, heterosis and epistatic effects were examined on post-weaning weight, height, length, girth, fat depth and muscle (ratio of stifle to hip width) with dry and wet season gains in these traits. The breeds used were two pure breeds (Jersey and Limousin), the Limousin${\times}$Jersey $F_1$, and two backcrosses ($F_1{\times}$Jersey dams and $F_1{\times}$Limousin dams). Direct genetic effects were large (p<0.001) for all traits except for length. Jersey maternal effects were large for weight, girth, fat depth and muscle in the post-weaning wet season gains which is an evidence of the impact of Jersey dam on progeny beyond weaning. There were large heterosis effects on fat depth and muscle relative to other traits. Epistatic effects were observed for post-weaning performance in weight, girth, fat depth and muscle. There are indications that there were different genetic effects for post-weaning compared to preweaning growth traits. Thus, it could be hypothesized from this study that different quantitative trait loci (QTL) affect early and late growth in Jersey and Limousin cross cattle breeds. The follow up work will examine the different chromosomal gene effects on pre- and post-weaning growth.

• Korean journal of applied entomology
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• v.34 no.1
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• pp.20-32
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• 1995

Adult diapause in insects is characterized by suppression of reproductive development. It is induced by environmental cues such as photoperiod, temperature, food availability, and other conditions Diapause-inducing environment is recognized and analyzed by the brain of the insects. The interpreted information is conveyed via endocrine system to target tissues such as ovaries, fat body, and other tissues. From this signal hierarchy of a brain-endocrine-target tissue axis, several factors are involved to express a diapause trait in a quantitative mode, even though the insects show a binomial phenotye between being in diapause or not. Recent works estimated that the number of the factors is relatively small by a series of crossing trials between high and low diapause lines. Heritability of the diapause is quite high (ca. 70%) in some species. Epistasis, sex-linkage, pleiotropism, and other nongenetic components also affect diapause inheritance. Most physiological studies have been focused on control mechanisms of the juvenile hormone (JH) synthesis in corpora allata (CA) because JH level in hemolymph of teneral adults is critical to decide a later developmental mode. Allatostatin, an antagonizer of JH synthesis, has been believed to be a potent brain message to CA for adult diapause induction.