• Korean Journal of Poultry Science
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• v.13 no.2
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• pp.173-178
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• 1986

Data on egg production, egg weight and egg mass were obtained from a sample of the Synthetic White Leghorn population which was raised at Poultry Breeding Farm, Seoul National University. Egg mass was not measured directly, but was calculated from the egg numbers and the average egg weight for same period. Phenotypic means, components of variance and covariance, heritabilities and genetic correlations were computed. Egg mass was estimated to be a lowly heritable trait (0.204-0.270). High heritability estimates were found for age at sexual maturity and egg weight. Genetic correlation estimates were high and positive between egg mass and egg number(combined estimates 0.711). Egg mass and egg weight were moderately correlated genetically (0.431). Genetic correlation estimates was -0.280 between egg number and age at sexual maturity, but was 0.524 between egg weight and age at sexual maturity. Results show that selection for total egg mass based on record from a single period will not be satisfactory unless the single period chosen is one in the latter part of the laying year.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.208-214
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• 1987

A genetic study on the panicle characters in Oryza sativa was carried out by means of a 5 x 5 diallel cross. The five parental varieties were Raekyung, Yeongnamjosaeng, Nongbaek, Yushin and Honenwase. All characters were correlated positively each other, except number of kernels per primary branch. The number of secondary branches per primary branch.was the most effective factor in determining the number of kernels per panicle, the next being the number of primary branches per panicle. Regression analyses of the data of Vr/Wr indicated the presence of non-allelic gene interactions for all characters. Overdominant characters were the number of kernels per panicle, the number of primary branches per panicle, the number of secondary branches per primary branch, the number of kernels per primary branch and sum of kernels on all the tertiary branches per panicle, suggesting that the characters were more influenced by dominant effect than additive effect. However, the number of kernels per secondary branch was partially dominant where the genetic variation was due more to additive effect than to dominance effect. But after omitting the parent which had non-allelic interaction gene, the characters; the number of kernels per panicle, the number of secondary branches per primary branch, and the number of kernels per secondary branch, were partially dominant. Narrow sense heritabilities(h$^2$ N) in number of kernels per panicle and number of secondary branches were high and moderate, respectively, but those of the rest were lower. Mean squares of GCA and SCA of all characters, except SCA of the number of kernels per secondary branch, were highly significant. Effects of GCA were larger than SCA effects in all characters. Raekyung, Yushin and Nongbaek had highly positive GCA, and the best positive SCA was observed in crosses of Nongbaek x Tongillines (Raekyung, Yushin, and Yeongnamjosaeng) in all characters.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.1
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• pp.78-83
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• 1979

Eight characters namely stalk length of trifoliate, stalk length of terminal leaflets, length of terminal leaflets, width of terminal leaflets, area of terminal leaflets, length of laternalleaflets, width of laternal leaflets, area of laternal leaflets in leaf parts of soybeans were measured to estimate the heritability values in percentage and relationships between those characters. Five parents and six different $_{x}\textrm{F}_2 generations and two backcross generations were used as the materials. The results obtained are summarized as follows: 1. Eight quantitative characters were differ from varieties. and hybrids from different cross combinations. 2. Heritability values of stalk length were showed the lowest, values of leaf length were lower than those of leaf width in both of main leaflets and laternal leaflets, and other values of leaf area in main and laternal leaflets were showed the highest values. 3. It was also recognized that there were close relationships between leaf length and leaf area, leaf width and leaf area in main leaflets and laternal leaflets, and area of main leaflets and laternal leaflets. There was, however, no any relationship between stalk length and other characters, and between length and width of main leaflets and laternal leaflets.

• Korean Journal of Agricultural Science
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• v.17 no.1
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• pp.26-33
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• 1990

This study was conducted to estimate heritabilities and genetic correlations of economic traits and body conformations in Korean Native Ogol fowl. The data analyzed were the record of 450 pullets bred from 150 dams and 20 sires of the fowl obtained from June 18, 1987 to February 6, 1989. The results of this study were summarized as follows ; The estimates of heritability for body weight, egg weight and shank length from combined variance components were relatively high, ranging from 0.415 to 0.558, while those for age at first egg, egg production and breast width were moderate, ranging from 0.301 to 0.334. For genetic correlations, body weights were negatively correlated with egg production, ranging from -0.552 to -0.309, while positive correlations were found between body weight and egg weight, ranging from 0.285 to 0.380. Also, egg production was negatively correlated with egg weight, ranging from -0.383 to -0.381. The shank length showed very high positive correlations with the body weights and age at 1st egg, ranging from 0.328 to 0.843. Hence the improvement in shank length will increase the body weight as well as the age at 1st egg.

• Korean Journal of Agricultural Science
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• v.6 no.1
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• pp.1-14
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• 1979

Selection index methods were applied to selecting better performing rice varieties with better plant characters from rice yielding trials tested under six different cultural methods. The results obtained were summarized as follows: 1. Varieties such as NO. 3, 4, 5 and 6 were selected as best performing varieties with good plant and grain characters. 2. Selection index I computed from Hazel's method was appeared effective for selecting rice varieties grown under general optimum environmental conditions, while selection index II computed from Pesek and Baker's desired genetic gain were effective for selecting rice varieties grown under rather stressed conditions. 3. The rank of mean yield of each variety was not completely in agreement with that of index values, which indicates the importance of other characters besides yield in selecting varieties. 4. Most characters studied were high in broad sense of heritabilities. 5. No significant interaction was found between varieties and cultural methods.

• Journal of the Korean Data and Information Science Society
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• v.22 no.6
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• pp.1145-1152
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• 2011

This study was conducted to estimate genetic effects on economically important traits for genetic improvement in Hanwoo by using the real-time ultrasound measurements for longissimus dorsi muscle area (LMA), backfat thickness (BFT), and marbling score (Marb). The phenotypic data were obtained from 1,648 pedigreed cows, and general linear models were applied to test the effects of age, region, and body condition socre. The cows between 50 and 60 months of age had the greatest scores for LMA and BFT, and Marb (P<0.05). The cows in region C had the greatest scores for body condition socre, LMA and BFT, while in region J Marb was the lowest (P<0.05). There was positive relation with LMA, BFT, and Marb according to increase body condition socre. Heritabilities for LMA, BFT, and Marb were estimated as 0.136, 0.351, and 0.236, respectively. These results would provide primary information for the efficient implementation of genetic improvement schemes in Hanwoo.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.12-17
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• 1986

Six genetic populations, viz, $P_1$, $P_2$, $F_1$, $F_2$, $B_1$, and $B_2$ of three crosses involving five varieties ($342{\times}$Kimjanggochu, Masan${\times}$Hungarian was, and Masan${\times}$Jeju) were used for estimating heterosis, heterobeltiosis, inbreeding depression, genetic components, heritability and correlations for fresh and dry anatomical components of red pepper. The results obtained were summarized as follows. Heterosis was positive in most characters of three crosses and heterobeltiosis was negative except in cross $342{\times}$Kimjanggochu. Inbreeding depression was positive, showing decrease of weight in $F_2$ generation. Duplicate and complimentary type of epistasis were concerned with the expression of characters, and broad and narrow sense heritabilities of fruit weight and pericarp weight were fairly high and stem weight, placenta weight and seed weight were low. Correlations among the anatomical components were positively significant in fresh and dry weights.

• Journal of agriculture & life science
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• v.46 no.5
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• pp.57-63
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• 2012

The purpose of this study was to estimate genetic parameters for productive traits in Duroc breed. In this study, 40,657 records for productive traits and the pedigree data of 47,974 families were collected from 41 farms registered at the Korean Animal Improvement Association (KAIA) from 2004 to 2011. The REMLf90 program was used to analyze a multiple traits animal model with fixed effects of sex, contemporary group, parity and age at the end of the test as covariate and random effects of animal and residual error. The heritabilities of days to 90 kg (D90KG), average daily gain (ADG), backfat thickness (BF) and eye muscle areas (EMA) were estimated to be 0.334, 0.340, 0.335, and 0.200, respectively. The genetic correlation coefficients were -0.992 between D90KG and ADG, -0.142 between ADG and BF, -0.361 between ADG and EMA, and -0.243 between BF and EMA. Conversely, positive genetic correlations for D90KG with BF and EMA were 0.13 and 0.36, respectively.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1340-1348
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• 2019

Objective: The objectives were to compare variance components, genetic parameters, prediction accuracies, and genomic-polygenic estimated breeding value (EBV) rankings for milk yield (MY) and fat yield (FY) in the Thai multibreed dairy population using five single nucleotide polymorphism (SNP) sets from GeneSeek GGP80K chip. Methods: The dataset contained monthly MY and FY of 8,361 first-lactation cows from 810 farms. Variance components, genetic parameters, and EBV for five SNP sets from the GeneSeek GGP80K chip were obtained using a 2-trait single-step average-information restricted maximum likelihood procedure. The SNP sets were the complete SNP set (all available SNP; SNP100), top 75% set (SNP75), top 50% set (SNP50), top 25% set (SNP25), and top 5% set (SNP5). The 2-trait models included herd-year-season, heterozygosity and age at first calving as fixed effects, and animal additive genetic and residual as random effects. Results: The estimates of additive genetic variances for MY and FY from SNP subsets were mostly higher than those of the complete set. The SNP25 MY and FY heritability estimates (0.276 and 0.183) were higher than those from SNP75 (0.265 and 0.168), SNP50 (0.275 and 0.179), SNP5 (0.231 and 0.169), and SNP100 (0.251and 0.159). The SNP25 EBV accuracies for MY and FY (39.76% and 33.82%) were higher than for SNP75 (35.01% and 32.60%), SNP50 (39.64% and 33.38%), SNP5 (38.61% and 29.70%), and SNP100 (34.43% and 31.61%). All rank correlations between SNP100 and SNP subsets were above 0.98 for both traits, except for SNP100 and SNP5 (0.93 for MY; 0.92 for FY). Conclusion: The high SNP25 estimates of genetic variances, heritabilities, EBV accuracies, and rank correlations between SNP100 and SNP25 for MY and FY indicated that genotyping animals with SNP25 dedicated chip would be a suitable to maintain genotyping costs low while speeding up genetic progress for MY and FY in the Thai dairy population.