• Journal of the Korean Society of Tobacco Science
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• v.6 no.2
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• pp.207-214
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• 1984

In order to obtain the basic information for the successful breeding of aromatic tobacco (N. tabacum L.), the combining ability and the mode of inheritance in 28 $F_2$ hybrids by diallel crosses between Korea local and oriental varieties were investigated. Estimates of general combining ability were significant for all characters investigated, and the specific combining ability was significant for stalk height, leaves per plant, leaf length, leaf width and days to flower. The partial dominance was exhibited by all characters investigated as well as additive effects were larger than dominance effects for all characters.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.135-141
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• 1989

The experiment was conducted to obtain basic information on breeding of flue-cured tobacco varieties. Nine cultivars and partial diallel set of 36 F1 hybrides were grown at Taegu Experiment Station, Korea Ginseng & Tobacco Research Institute in 1983. Estimated heritability in the narrow-sense ranged from 66.21% to 94.12% for yield, leaves per plant, days to flower, leaf weight, leaf width, leaf shape, nicotine content and reducing sugar content, while that for stalk height, leaf length, midrib weight and midrib width ranged from 28.12% to 56.25%. The genotypic correlations were positive among yield, leaf weight, leaf length, leaf width, midrib weight and midrib width in the middle leaves, days to flower, nicotine content and reducing correlated with leaf length than leaf width. At the path coefficient analysis of the effect of leaf and midrib characters upon yield according to stalk position, leaf weight, leaf width and midrib width in the middle leaves, and leaf weight, and leaf width in the top leaves showed high direct effects.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.97-104
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• 1998

Mainly due to limited genetic resources available and also urgent need for hybrids suitable to local conditions, conventional theories and regular methods for bivoltine silkworm breeding are not easily applicable in such a tropical country as Sri Lanka which is recently planning to scale-up the silk industry. A simplified but practical methodology was introduced to overcome such constraints. Through application of such modified informal breeding methods, two hybrids named DP0308 and DP0314 were selected for cocoon production. Details of the altered method of germplasm improvement in the silkworm are presented, along with combining ability and heritability estimates for six parental pure lines in a half-diallel cross.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.2
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• pp.40-45
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• 1978

Degree of dominance for culm length, panicle numbers, flag leaf fwidth and panicle weight showed higher values than the others, and additive protions in variance components were more greater than heterosis protions for many characters. Average gene frequency showed low values for all characters, GCA were more greater than SCA, and the effects of GCA and SCA were differ from parents, crosses, generation and characters.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.1
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• pp.3-11
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• 1984

In order to obtain the basic information for the successful breeding of aromatic tobacco (Nicotiana tabacum L.), the heterosis, combining ability and gene distributions in 28 Fl hybrids by diallel crosses between Korea local and Oriental varieties were investigated. The yield were higher, stalk height, leaf length and leaf width were larger and days to flower was shorter for the Fl hybrids when compared to mid-parent. Estimates of general combining ability were significant for all characters investigated, and specific combining ability were significant for yield, stalk height, leaves Per Plant, leaf width and days to flower. In vr-wr graph, partial dominane was exhibited by all characters investigated.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.216-226
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• 1983

Genetic studies on the $F_2$ generation of a set of half diallel crosses involving six cowpea varieties were conducted. by the randomized block design with three replications to determine combining ability, gene action and the relationships between parents and their $F_2$ hybrids. The 12 agronomic characters namely, days to flowering, days from flowering to maturity, days to maturity, diameter of stem, length of internode, number of branches per plant, length of pod, number of pods per plant, number of grains per pod, number of grains per plant, 100 grain weight and grain weight per plot were observed, and the $F_2$ generation of this diallel set of crosses was analysed for each character according to the method by Jinks and Hayman. The results obtained are summarized as follows: 1. Vr-Wr graphical analyses; The following seven characters, days to flowering, number of branches per plant, length of pod, number of pods per plant, number of grains per plant, 100 grain weight and grain weight per plot appeared to be partially dominant, and over dominance was found for days from flowering to maturity, days to maturity, length of internode and number of grains per pod. But diameter of stem indicated partial dominance near complete dominance. 2. Estimates of genetic variance components; In the degree of dominance,. eight characters, that is, days to flowering, days from flowering to maturity, days to maturity, length of internode, number of pods per plant, number of grains per pod, number of grains per plant and grain weight per plot were expressed larger than 1. And the characters, days from flowering to maturity, number of branches per plant and number of grains per plant as the degree of mean dominance ($H_1$/D) were found to be negative value over other characters. On the other hand, apprent asymmetry of dominance-recessive allele ($H_2$ /$4H_1$) produced comparatively estimates with lower value on days from flowering to maturity, length of internode, number of branches per plant and number of grains per pod. 3. Analyses of combining ability; Mean square value of GCA(general combining ability) appeared to be more important than those of SCA (specific combining ability) for most characters, and among them, grain weight per plot showed the highest mean square value in GCA and SCA. 4. Effect of combining ability; Variety 178 was expressed as the highest GCA effects in five characters (days to flowering days to maturity, number of pods per plant, number of grains per plant and grain weight per plot). SCA effects were differed from parents, characters and crosses, but crosses between TVu 1857 $\times$ TVu 2885 and TVu 2702 $\times$ J78 were shown to be highly with SCA effects on yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.395-401
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• 2002

The combination of early heading time, maturing time and short grain-filling period is very important to develop early varieties in winter barley. The 4 parental half diallel crosses (parents, $F_1$s, $F_2$s) were cultivated at the field. The heading date was from April 3 to 26, maturing date from May 15 to 27 and grain-filling period from 31 days to 42 days, showing that the varietal differences about the 3 traits were remarkable. According to half diallel cross analyses, Dongbori 1 for heading time (late heading) was dominant, but Oweolbori (early heading) was recessive, showing partial dominance with high additive component of genetic variance. Dongbori 1 for maturing time was dominant, but Oweolbori was recessive, showing partial dominance with high additive variance. Reno for grain-filling period (short grain-filling period) was dominant, but Oweolbori (long grain-filling period) was recessive with additive, and partial dominance. There were highly significant mean squares for both GCA and SCA effects on the heading and maturing times, and GCA/SCA ratios for all traits were high, showing the additive gene effects more important. Sacheon 6 and Oweolbori had greater GCA effects for early heading and maturing times, and Dongbori 1 and Reno had greater GCA effects for late times. GCA effects were highly significant in $F_1$ and $F_2$ generations, showing high GCA/SCA ratios (7.02). The heading and maturing times in field were positively correlated with antifreeze proteins concentrations, accumulation, resistance to photoinhibition and winter survival, respectively) but the grain-filling period did negatively correlated with the trails.

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.189-198
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• 2017

This study was conducted to develop a new synthetic breed of Korean native chicken. The combining ability and reciprocal effects for production traits were estimated on 1,157 hens from a $5{\times}5$ diallel cross-mating design using grand parent stock (GPS) lines of Korean native chicken. Body weight, viability, age at first egg laying, egg weight, and hen-day egg production were measured and analyzed. The results showed that the general combining ability (GCA) of the survival rate during laying periods was -9.6 to 11.1, with the highest value obtained in the W strain. Additionally, the GCA of the body weight at 12 weeks was -209.7 to 162.2, with the highest value obtained in the F strain. The GCA for age at fist egg laying was estimated to be -2.8 to 3.7, while the GCA of egg weight was -0.91 to 0.96, and the GCA of hen-day egg production was -4.9 to 6.0. In the estimation of specific combining ability, the YW combination showed the highest survival rate, FW showed the highest body weight at 12 weeks, and GW showed the highest hen-day egg production. The reciprocal effects were significantly different among crosses for almost all productivity traits. In identical breeding combinations, differences in ability were observed when the maternal or paternal breeds were switched. The mean value based on combining ability was higher in WY, WF, and GW combinations for survival rate; GF, HG, and HF combinations for body weight at 12 weeks; and GW, YW, and FW combinations for hen-day egg production. It is concluded that the GF and HF combinations, which have excellent growth performance and moderate survival rate, are the most desirable paternal parent stock (PS) strains, and the GW and FW combinations, which have great laying performance and moderate body weight, are the most desirable maternal PS strains.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.123-134
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• 2017

This study was conducted to establish new synthetic lines of Korean Native Chicken. We performed $5{\times}5$ diallel crossings with GPS lines of Korean Native Chicken for the selection of parent stock. The production traits including viability, body weight, age at first egg laying, egg weight, hen-day egg production, and hen-housed egg production were measured and analyzed for 25 crosses with 1,157 hens. The heterosis effects of these traits were also estimated. The results showed that the average survival rate during laying periods was 67.7% in the pure lines and 77.1% in the crosses. The 25 cross combinations were shown to be distinctly divided into three groups according to body weight; nine crosses in the high-weight group, 12 crosses in the medium-weight group and four crosses in the light-weight group. The average body weight at 12 weeks of age was $1,873.8{\pm}43.0g$ in the high group, $1,595.4{\pm}56.6g$ in the medium group and $1,152.7{\pm}24.7g$ in the light group, and $1,560.2{\pm}339.3g$ in the pure lines and $1,640.9{\pm}213.7g$ in the crosses. In terms of egg production performance, the age at first egg laying was $139.7{\pm}4.9$ days in the pure lines and $135.8{\pm}5.1$ days in the crosses. The average egg weight was $52.3{\pm}1.6g$ in the pure line and $53.0{\pm}1.6g$ in the crosses. The average hen-housed egg production from 20 to 40 weeks was $58.3{\pm}12.9$ eggs in the pure line and $69.2{\pm}10.4$ eggs in the crosses. The average heterosis effect was 16.9% for survival rate, 5.4% for body weight at 12 weeks, -2.7% for age at first egg laying, 1.3% for egg weight, and 14.3% for hen-day egg production. Generally, the heterosis effect for viability and egg production traits was higher than that for growth trait. On the basis of these results, it is expected that the selection of the HF combination, which had excellent growth performance, is the most desirable as the paternal strain, and the selection of GW and FW combinations, which had excellent laying performance, are preferable as the maternal strain.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.70-79
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• 2002

This study was conducted to determine correlations and combining abilities of leaf lengths, leaf widths, petiole lengths, number of branches, number of leaves, leaf areas, fresh weights, dry weights and number of flowers in F₁ crosses made with the partial seven-parent diallel cross in Viola tricolor. Leaf lengths and leaf widths showed highly positive correlation with petiole length and negative correlation with number of branches, number of leaves and number of flowers. There was positive correlation between the number of leaves and flowers as well as between leaf area and fresh weight. Mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for all the parameters. Variance component values of SCA were greater than those of GCA for all the parameters except leaf length, implying preponderance of non-additive gene actions for these characters. The lines C and G for leaf lengths and widths, the lines A and F for number of leaves, the lines A, B and G for leaf areas, and the lines B and F for number of flowers showed relatively high GCA effects. The crosses of A×B and B×D exhibited high SCA effects on increasing leaf lengths, leaf widths, number of leaves, fresh weights and number of flowers. And also the crosses of B×E and D×G exhibited high SCA effects on decreasing leaf lengths, leaf areas and fresh weights as well as increasing number of flowers. The broad sense heritabilities of most characters were high compared with the narrow sense one. Those of leaf length, leaf width, petiole length and number of leaves were high in both the broad and narrow sense heritabilities.