• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.25-30
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• 1988

Seven rice varieties and $42F_1$ hybrids of $7{\times}7$ diallel cross were used in genetic analysis for grain size, weight and shape. Effects of average heterosis for grain length and shape showed significantly negative values. GCA, SCA and RCA variances were significant for all characters and also additive variance was more important than dominance variance for grain length, width, thickness and weight. GCA effects of BG 2 and Arborio were highly positive for grain size and weight, and those of BG 2 and Nagdongbyeo were highly negative for grain shape. Partial dominance was observed for all characters. The direction of dominance was negative for grain length, width and shape, and ambidirections for grain thickness and weight. The effective gene number was two for grain length and shape. Both narrow and broad sense heritability were high in all characters.

• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1A
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• pp.15-26
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• 2010

Quasi-static tests were conducted to evaluate structural performance of precast piers prestressed by bonded prestressing steels. Combinations of prestressing bars and normal reinforcing bars, embedded steel tubes and prestressing strands were used as continuous steels crossing the joints of a precast pier. Main design parameters were steel ratio, magnitude of prestress force, and section details. Flexural strength and energy dissipation capacity of precast columns with higher steel ratio showed better performance due to continuous steels after opening of the joints. Precast piers with embedded members showed stable behavior after reaching maximum loads resulting in higher displacement ductility and energy dissipation capacity increased as the introduced prestress increased. Self-centering behavior at early stages and stress increase of confining reinforcements were observed from highly prestressed columns. Combination of prestressing steels and normal reinforcing bars should be used in design to prevent rapid strength degradation after reaching the maximum load.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2002.11a
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• pp.140-142
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• 2002

This study was conducted to obtain some genetic information for developing superior Korean native chickens. Heterosis and combining ability effects were estimated with 1,080 progenies of full diallel crosses of 3 strains in Korean Native Chicken. The traits of egg productivity were Investigated, and heterosis effect, general combining ability, specific combining ability and reciprocal effect were analyzed model I of the Griffing's method 1. The general performance were 147.0 days in age at first egg laying, 71.8 eggs in egg numbers to 270 days, 50.1g in egg weight at 270 days, 75.6 in egg shape index, 356$\mu\textrm{m}$ in egg shell thickness, and 4.27kg/$\textrm{cm}^2$ in egg shell strength, respectively. According to result, heterosis effect revealed comparatively high in age at first egg laying, egg numbers, egg weight, and egg shell strength. The effects estimated highly in general combining ability for age at first egg laying, egg numbers, egg weight, egg shape Index and egg shell thickness, and in specific combining ability were egg numbers, egg weight and egg shell thickness, and in reciprocal effects for egg numbers, egg shape index, and egg shell thickness. This result could be used for developing Korean native chicken.

• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.7-14
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• 1987

Extensive studies were undertaken to analyze the genetic basis of economically important quantitative characters in the silkworm by diallel crosses of four inbred lines differing widely in silk yielding ability. Some differences between the reciprocal corsses were detected in cocoon weight, cocoon shell weight, cocoon filament length and cocoon filament weight in case the parental lines were greatly differenent each other in silk yielding ability. The general combining ability (GCA) varied with the inbred lines and M242, a Chieese sexlimited larval marking variety showed high GCA value in the economic characters, such as cocoon yield, cocoon weight, cocoon filament length and weight, and raw silk percentage. The highest heterosis effect, about 13% to 14% was seen in cocoon and raw silk yield and it was low in cocoon reelability and raw silk percentage with less than 1%. It is advisable to improve highly heritable quantitative characters such as larval duration, cocoon shell weight, cocoon filament length and raw silk percentage by means of selection, and to select single crosses with high heterosis effect for cocoon weight and cocoon yield which show overdominance. Genetic correlation should be considered when more than two characters are targets for improvement and selecting high cocoon shell weight is effective to breed high silk yielding varieties. It is difficult to improve cocoon reelability because of low heritability (0.11) and its negative correlation with cocoon-silk quality.

• Korean Journal of Poultry Science
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• v.12 no.2
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• pp.75-82
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• 1985

This study was carried out to estimate combining abilities and heterosis in White Cornish and White Plymouth Rock. The data were obtained over an 8weeks period from 3rd Oct., 1984 to 28th Nov. 1984 at the Livestock Experiment Station. A total of 810 birds, composed of 369 pure strains, 270 two-way crosses, and 180 fourway crosses were average amount of heterosis expressed as a ratio was 1.63% for livability, 5.47% for body weight at 8 weeks, 5.57% for weight gain from day old to 8 weeks and -5.98% for feed requirement. Specific combining ability were statistically significant for all of the traits examined in this study. Although the general combining ability was not significant for any of the traits, strain A appears to be superior to other strains.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.436-442
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• 1987

The variations of the anther and pistil length of some rice cultivars at the different planting density and fertility levels were tested and their inheritance mode was studied. The anther length of a spikelet on a secondary panicle branch was longer than the one of a spikelet on a primary panicle branch. In the cultivar Z97B, both the anther and the pistil length were increased slightly along the increased plant-ing spacings, But, in the cultivar IR43 no general tendency was observed. The fertilizer levels applied n the field did not affect both the anther and pistil length of a given cultivar. In a cross of IR56/IR8, the anther length showed continuous variation with longer anther being recessive in the F2 population. While, the pistil length showed a continuous variation with longer pistil being over-dominance. In all of the crosses which IR56 involved, the general and specific combining abilities were high for both the anther and pistil length. The broad sense heritability for anther length was 0.46, and for pistil length was 0.88. The correlation coefficients of anther length and pistil length were 0.33 for phenotypic and 0.44 for geno-typic.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.89-93
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• 2001

To obtain the basic information for varietal improvement and cultural practice, source and sink relationship in the diallel grafting was analyzed among five sweet potato cultivars, Yulmi, Shinyulmi, Gunmi, Hongmi and Seonmi, whose source and sink capacities are different one another. General grafting effect(GGE), specific grafting effect(SGE) and reciprocal grafting effect(RGE) of top weight, tuberous root weight and total weight showed considerable differences. Grafting decreased total dry weight but its effect was different among grafting combinations. Growth and dry matter production of top were affected more by scion, while those of underground were influenced more by stock. Shinyulmi which has great potential source and sink capacities resulted the highest total dry weight, while Hongmi and Yulmi which have low potential source capacity resulted the lowest total dry weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.652-657
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• 2006

Combining ability and heterosis for $F_{1}$ population obtained $5{\times}5$ half diallel cross in sesame were estimated for six quantitative characters. The parental varieties used for diallel cross were Yangbaek and Ansan of normal type, Suwon 177 and 195 of placenta adhesion type (PA) and SIG960320-5-1-1 of indehiscent type (ID). PA and ID type are shattering-resistant sesames and Yangbaek and Ansan are shattering sesames. The high heterosis of $F_{1}$ hybrids was expressed in the number of capsules per plant (NC), grain yield per plant (GY) and number of branches per plant (NB). Shattering.ate (SR) showed high positive heterosis toward increase of seeds shattering in all the combination of $F_{1}$ generation which was presumed because the characters connected with shattering resistance of seeds were governed by recessive gene. At the analysis of combining ability, highly significant general combining ability (GCA) effects were observed on all the characters in $F_{1}$ generation, significant specific combining ability (SCA) effects were observed on the NC, GY and SR. GCA variances were greater than SCA variance, which suggested that additive gene effects were greater than other nonadditive gene effects. Considering the estimated GCA effects, Suwon 195 (PA type) was found to be good parent for SR and GY, SIG960320-5-1-1 (ID type) was poor for GY and plant height. SCA effect for NC was great in Yangbaek/Suwon 195, SCA for GY was great in Ansan/SIG960320-5-1-1, and SCA for decrease of SR was great in Ansan/Suwon177.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.31-36
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• 1988

A seven-parent half-diallel cross was analyzed for white center, white belly and alkali digestibility value(ADV). The analysis of variences were significant for all characters at 1% level. Both general and specific combining ability were significant for all characters. Non-additive genetic varience predominated for ADV(12hr. treatment) and additive effects were more important than non-additive effects for other characters. With the exception of ADV(12hr. treatment), which showed complete dominance, partial dominance in a negative direction was observed for the other characters. Heritability values were high in all characters. White belly was high positively correlated with white center and ADV.