• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.303-310
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• 2023

The current study was conducted to compare the effect of crossbred on the body weight and laying performance of Korean native chicken from hatch to week 40. A total of 873 one-day-old chicks were divided into twelve crossbreds (i.e., CFCK, CFYC, CFYD, CKCF, CKYC, CKYD, YCYD, YCCF, YCCK, YDCF, YDCK, and YDYC) and commercial layer (Hy-Line Brown) were obtained as a counterpart in the study. All the birds are raised in battery cages (76 × 61 × 46 cm³) and then raised until 14 weeks and subsequently moved to layer battery cages (60 × 25 × 45 cm³) and raised until 16 weeks. The body weight and viability were measured biweekly from hatching to week 16. The week of 16, body weight range was about 1,010.24 to 1,411.77 g. The body weight of specific crossbreeds (i.e., CKCF, YCYD, and YDYC) was found to be comparable to that of Hy-Line Brown). The viability hatch to week 14 range was about 55 to 100% and however week 14 to 16 range was 80 to 100%. The crossbred (i.e., CKCF) recorded superior (P<0.05) viability throughout the whole experiment period, even compared with Hy-Line Brown (100% vs 96%). Our results are indicating that crossbreds Korean native chicken including CKCF, and YDYC has the potential to enhance key features of laying hens during the growing phase like optimal body weight and higher viability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.175-184
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• 1995

In order to substitute sweet and super sweet maize hybrid seeds which are introduced at current, and to meet national demand for human consumption, inbreds and hybrids of waxy maize were developed by using Korean native lines, Six inbreds were used to produce 15 hybrids in a diallel cross, Six inbreds used were significantly different in tasseling dates, plant and ear heights, leaf area, and shank length, The inbred line, Bosung showed the longest shank length among the lines used, The ear characters like ear length and diameter, 100 kernel weight, row number, and kernel number per ear varied among lines, The inbred line Bosung was again significantly different from other lines in ear length and diameter, row number and 100 kernel weight. However, ]ewon had the highest kernel yield per 100. Hybrids were also different in plant and ear characteristics depending upon the inbreds used. The hybrids of Bosung showed the longest ear length and the heaviest kernel weight. Highest kernel yield per unit area was obtained by the hybrids crossed with Dangjin, The general combining ability(GCA) of Dangjin was found very effective in reducing plant and ear height of hybrids. The GCA of Jewon was very effective in increasing tiller number per plant. The inbred line Bosung was effective in increasing ear length and 100 kernel weight and in decreasing row number. The hybrid which showed the highest specific combining ability in ear length and 100 kernel weight was Jewon Chilbo.

• Journal of Sericultural and Entomological Science
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• v.27 no.2
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• pp.7-19
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• 1985

The genetic variances and combinding ability of some useful characters were analyzd on sixty four combinations in the 8$\times$8 diallel cross using the four Japanese races(Jam 107, Jam 113, Jam 117 and Jam 119) and the four Chinese races(Jam 108, Jam 114, Jam 118 and Jam 120). The eight quantitative characters were the total larval stage period(TP), the fifth larval instar period(FP), the female cocoon total weight(FW), the male cocoon total weight(MW), the female cocoon layer weight(FL), the male cocoon layer weight(ML), the female cocoon layer ratio(FR), and the male cocoon layer ratio(MR). The results were as follows: The analysis of the genetic variance and the combining ability in the TP and the FP. In TP and FP, h2N was less than h2B. The GCA, SCA and RCA were at a high significant level. Hl/D and (Hl/D)1/2 ere large. The heterosis were small minus. E and D were large. The r was in the positive direction, because the recessive genes were mainly expressed as a short rearing periods. The regressions of the characters were passed below 0 point, because the characters in the TP and the FP were appeared overdominant. The order of the dominance in the TP of the parents were in the order of Jam 119>Jam 113>Jam 117>Jam 108>Jam 120>Jam 114>Jam 107>Jam 118, and that in the FP of the parents were followed in the orders of Jam 117>Jam 113>Jam 108>Jam 114>Jam 119>Jam 107>Jam 120>Jam 118. The analysis of the genetic variance and the combining ability of the FW and the MW. In the FW and the Mw, h2N was less the h2B. The GCA and SCA were large but RCA was little. Hl/D and (Hl/D)1/2 in the parents were large. Heterosis was large. E was appeared large in the FW, and small in the MW. D was small. The r was of the minus direction, because the dominance genes were less expressed. The regression of the these characters were padded below 0 point, because the characters in FW and MW were appeared overdominant. The orders of the dominance in the FW of the parents were as the order of Jam 107>Jam 108>Jam 119>Jam 113>Jam 114>Jam 120>Jam 117>Jam 118, and in the MW of them in the order of Jam 114>Jam 120>Jam 108>Jam 113>Jam 107>Jam 119>Jam 117>Jam 118. The analysis of the genetic variance and the combining ability of the FL and ML. In the FL and the ML, h2N was less than h2B. GCA and SCA were large. RCA was little. Hl/D and (Hl/D)1/2 ere large. Heterosis was large. The r was in the negative direction, because the dominance genes were less expressed. The regression of the characters of FL and ML were appeared overdominant. The dominance in the FL of parents ere in the order of Jam 120>Jam 114>Jam 119>Jam 119>Jam 118>Jam 107>Jam 117>Jam 113, and the ML of them in the order of Jam 114>Jam 108>Jam 120>Jam 117>Jam 118>Jam 107>Jam 119>Jam 113. The analysis of the genetic variance and combining ability of the FR and the MR. In the FR and the Mr, h2N was less than h2B. GCA was large. The SCA and RCA were little. In the FW, Hl/D was large but (Hl/D)1/2 was a little. In MR, Hl/D and (Hl/D)1/2 both were a littel. Heterosis was a little. E in the FR was in the negative direction, because the dominance genes were less expressed but that in the MR was the positive direction because the recessive genes were mainly expressed. The order of the dominance in the FR of the parents were in the order of Jam 117>Jam 114>Jam 108>Jam 120>Jam 118>Jam 119>Jam 107>Jam 113 and that in the MR these were in the order of Jam 114>Jam 117>Jam 108>Jam 118>Jam 107>Jam 119>Jam 120.

• Journal of Sericultural and Entomological Science
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• v.22 no.2
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• pp.1-7
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• 1981

Diallel crosses among six silkworm varieties were used as the materials by the randomized block design. and combining ability tests were conducted to determine the relationships between parents and their F$_1$ hybrids. The six parents and their 30 F$_1$ crosses were evaluated for five quantitative characters in each female and male silkworms. Mean values of period(days) of larval stage in mid-parent were more than those of each F$_1$ hybrids. Highly significant differences were shown in the total cocoon weight and weight of cocoon layer of silkworms in F$_1$ hybrids of 111$\times$114, 111$\times$ yunil, 114$\times$yunil and those of reciprocal crosses. From the results, it was recognized that varieties A(111), D(114) and F(yunil) were useful varieties as the parents in breeding of silkworms for increasing the total cocoon weight and weight of cocoon layer, etc. Differences among crosses in apparent degree of heterosis existed for total cocoon weight of cocoon layer and cocoon layer ratio, etc. Mean square values of GCA (general combining ability) were more greater than those of SCA(specific combining ability) for period(days) of larval stage, period (days) of 5th instar and cocoon layer ratio of silkworms. The effects of GCA were differ from parents and characters and the effects of SCA were also differ from parents, characters and crosses.

• Journal of Practical Agriculture & Fisheries Research
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• v.3 no.1
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• pp.85-93
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• 2001

The inter-relationship and combining abilities of characters for leaf length, leaf width, branch number, leaf number, leaf area, fresh weight and dry weight were studied in the F₁ combination of 15 crosses from the partial six-parent diallel cross in Petunia hybrida. The leaf area, fresh weight and dry weight showed high positive correlation together with the other growth characters such as leaf length, leaf width, branch number, leaf number. The mean squares of general combining ability(GCA) and specific combining ability(SCA) were highly significant for all the growth characters. The estimates of variance components of SCA were greater than those of GCA for all the characters, showing preponderance of non-additive gene actions for these characters. GCA effect was high in the lines of D and G for leaf length and fresh weight, and in the lines of C and D for branch number, leaf number, leaf area and fresh weight. The crosses of D×E, D×G, and E×G exhibited high SCA effect for all the growth characters such as leaf length, leaf width, branch number, leaf number, leaf area, fresh weight, and dry weight. The broad sense heritability was generally high compared to narrow sense one in the 7 characters. The highest heritability of the broad and narrow sense was shown in the leaf width and dry weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.489-494
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• 1993

The amount of maize being imported from other countries to meet the national demand are increasing every year. Regardless of the usage whether it is for silage or for human consumption, amount of seeds for farmers are ever being increased. In order to solve the problems arising from the seed import, a program for developing waxy hybrids with high quality was set up at the College of Agr., Chungnam National University. The main breeding targets for high quality waxy hybrids are focused on the pericarp thickness. In order to obtain basic information needed for developing hybrids with thin pericarp, six inbred lines all derived from open pollinated Korean waxy lines were diallel crossed. Results obtained indicate that waxy hybrids with thin pericarp can be developed by choosing proper parental lines. Of the six inbreds, Jewon inbred had utmost thin pericarp compared with other lines. Hybrids crossed with Jewon showed also thinner pericarp than other hybrids. However, Danyang which has thick pericarp showed thicker pericarp in hybrid combinations. Variance due to general combining abilities was greater than the variance due to the specific combining abilities, indicating that additive gene effects are more important. The pericarp thickness of waxy hybrid endosperm varied with the parts of pericarp. The germinal side of the pericarp is comparatively thinner than the abgerminal side. The upper part (crown) has thicker pericaip than lower part (tip) of the kernel.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.92-93
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• 2000

• Journal of the Korean Data and Information Science Society
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• v.13 no.2
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• pp.175-184
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• 2002

In this paper, diallel crosses block designs for control versus test comparisons among the lines are proposed. These block designs are constructed by using partially balanced incomplete block designs with C-properties. Also, the efficiencies of the diallel crosses block designs obtained through this method are tabulated for number of lines 22 or less.

• Korean Journal Plant Pathology
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• v.1 no.2
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• pp.136-140
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• 1985

The studies were conducted to test for combining ability and to evaluate resistance to maize dwarf mosaic virus (MDMV) by diallel crosses of corn inbreds. For the genetic analysis of the resistance, a diallel set of crosses without reciprocals was made using the eight corn inbreds which had different degrees of resistance to MDMV. Twenty eight $F_1$ hybrids showed different symtom severity. the highest value is 3.63 and the lowest value is 1.87 in disease ratings (1-4). General combining ability (GCA) for resistance to MDMV was highly significant, but specific combining ability (SCA) was not significant. Two inbreds, A632 and KS15 showed negative GCA effects, indicating that these parents were good general combiners and that resistance to MDMV increased in hybrid combinations. Hyrid A632 x KS5, showed the highest negative SCA effect and several combinations showed negative SCA effects. The analysis of parent-offspring covariance (Wr) and array variance (Vr), suggest that there may be many dominant genes in the resistant inbreds and many recessive genes in the susceptible inbreds.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.83-95
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• 2024

This study aimed to assess the performance of laying hens across twelve crossbreed strains (i.e., CFCK, CFYC, CFYD, CKCF, CKYC, CKYD, YCYD, YCCF, YCCK, YDCF, YDCK, and YDYC) of Korean native chicken (KNC) and compare them with Hy-Line Brown layers. A total of 287 18-week-old laying hens were placed in battery cages by strains (2-5 birds per pen). Results indicated that the YCYD and YDYC strains exhibited numerically heavier body weights than Hy-Line Brown at week 18-64. CKYC and YDYC strains demonstrated more than 94% viability by week 64. The CFYC strain had an age of first egg laying of 127 days, and the YDCF strain reached an age of 50% egg production at 140 days, both earlier than their parent stock. The YDCF strain showed over 70% egg production for up to 60 weeks. Regarding egg quality, the CKCF and YCCF strains had numerically higher egg weights among the KNC groups at week 24-64, with the YDYC strain showing a darker (P<0.05) eggshell color compared to CKCF at week 40. Moreover, KNC crossbreeds showed a higher (P<0.05) egg yolk ratio than Hy-Line Brown. In conclusion, the YDCF and YCCF crossbreeds exhibited the most desirable new synthetic Korean native commercial layer based on egg production and quality parameters. Therefore, these strains could be a viable substitute for Hy-Line Brown layers.