• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.35-36
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• 1998

• Korean Journal of Plant Resources
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• v.3 no.1
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• pp.1-30
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• 1990

The traditional plant imprownent methods consisted of pure line selection, cross breeding, heterosis breeding, polyploid breeding, mutati-onbreeding, ect.Biotechmoiogy is divided into gene spliclng , monocle-nal antibodies , protein engineering , agricultural research, and microbiological engineering. Of these , high plants deal with agricultural research, and the importent part of which is tissue culture and celLculture , Tissue .culture and cell culture are again divided into embryoculture, test tube fertilization, anther and pollen culture, somatichybridization , transformation, recombination, recombinant DNA moleculehybrid plasmid, ect For these haploid production, protoplast culture,protoplast fusion, selection and propagation, ect. , the technical sett-lement is needed.

• Proceedings of the Korean Society of Crop Science Conference
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• 1997.05a
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• pp.14-15
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• 1997

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.475-479
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• 1998

Data on body weights were analyzed in the four genetic groups from all possible crosses of two subspecies of mice to estimate average direct genetic effects (ADGE), average maternal genetic effects (AMGE) and heterotic effect (HE). The genetic groups used were $CF_{{\sharp}1}$ laboratory mouse (Mus musculus domesticus), Yonakuni wild mouse (Yk, Mus musculus molossinus yonakuni) and two reciprocal $F_1$ crosses of them, CY and YC. First symbol in the reciprocal $F_1$ represent subspecies of dam. Body weight at 1 (Wk1), 3 (Wk3), 6 (Wk6) and 10 weeks of age (Wk10) were analyzed from 258 mice of the four genetic groups. The model used to evaluate body weights included main effects of genetic group and sex, and interaction effect between genetic group and sex. The ADGE and the AMGE were estimated as deviations of Yk from $CF_{{\sharp}1}$. The HE was estimated from the differences between the reciprocal $F_1$ and the midparent mean. Results of this study showed that all effects, except sex and interaction between genetic group and sex at Wk1 and Wk3, were highly significant source variation (p < 0.01). The ADGE were positive and highly significant (p < 0.01) at all ages studied for both sexes, while the AMGE were highly significant at Wk3, Wk6 and Wk10. The ADGE were larger in contributing effect on body weight differences than the AMGE. The positive value of the HE were observed at all ages for males, while for females the positive effects occured from birth through weaning.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1536-1540
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• 2006

Crossbreeding effects for wool quality traits viz. greasy fleece weight (kg), staple length (cm), average fibre diameter (${\mu}$) and medulation percentage were estimated using the Dickerson's and Kinghorn's models. The data analyzed involved 15 genetic groups including Nali purebred, $F_1$'s of two and three breeds, $F_2$'s and reciprocal crossbred obtained from the crossing of Nali (N), Merino (M) and Corriedale (C) breeds during 1980-96. Nali and Corriedale breeds had non-significant negative additive genetic effects (Dickerson's model) on greasy fleece weight, while effects of Corriedale were negative for staple length only from both models. In general additive genetic effects of all three breeds were non-significant for all the wool traits except medulation percentage. Non significant heterotic and recombination effects (epistatic loss) were estimated from both models. However, the estimates of crossbreeding effects varied between the models both in magnitude as well as in direction barring few exceptions. Undesirable positive heterosis was found on medulation percentage for all types of combinations involving three breeds. Comparison of least squares means of various genetic groups revealed that both two breed and three breed crosses were superior to the Nali breed for all wool quality traits. Fibre diameter of MN crossbreds was significantly less than CN crossbreds. Results also indicated that as the inheritance of Nali breed in a cross is decreased, the medulation percentage decreases which is desirable. Inter se mating of crossbreds (two breed, three breed) has not resulted in a decline in the wool quality traits. These results indicate that the synthetic population derived from three breeds can be stabilized easily for wool traits as there may not be epistatic loss on subsequent inter se mating of crossbreds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.473-480
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• 1995

This study was conducted to know how cold tolerance of rice varieties is inherited. Several crosses were made between cold tolerant varieties and susceptible varieties, and their progenies were morphologically and physiologically evaluated each characters at cold water and natural conditions. The segregation modes of leaf discoloration by cold treatment in F$_2$ generations are agreed to simple inheritance ratio of R3 : Sl in four crosses among total seven cross combinations. In F$_1$ and F$_2$ generations, tall one was dominance in culm and panicle length and less reduction in culm and panicle length by cold treatment was overdominance or partial dominance, while more number of panicles per plant was dominance and more increasing of panicle numbers by cold water irrigation was overdominance. Heritability and heterosis in most characters showed high values, and heterosis in remote crosses was especially larger under the cold water treatment condition compare with that under natural condition.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.2
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• pp.126-132
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• 1992

This experiment was conducted to examine estimates of heterosis, degree of dominance, heritability and phenotypic and genotypic correlation for several mutant characters in flue-cured tobacco variety. Significant heterosis was noted, recording 2.73 and 6.16% for leaf width, -6.86 and -4.72 for leaf shape index, 19.8 and 23.4% for bacterial wilt disease index in Fl an4 F2 generation, respectively, and -1.44 for days to flower in F2 generation. And also leaf width was appeared partial dominance in Fl, and leaf shape index in Fl and F2, Leaf width in F2 was appeared overdominance. Estimated heritabilities in the broad sense ranged from 0.77 to 0.87 for plant and stalk height and days to flower, while those of leaf number, leaf length and width, leaf shape index and bacterial wilt disease index ranged from 0.50 to 0.65. And the heritabilities in the narrow sense were appeared 0.64 and 0.72 for stalk and plant height, respectively, and the others were ranged from 0.32 to 0.47 Positive genotpic correlations appeared among plant height, stalk height, leaf length and leaf width, and between leaf shape index ands day to flower. And negative genotypic correlations appeared between leaf shape index and plant height and stalk height and leaf width, and between bacterial wilt disease index and leaf length.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1371-1377
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• 2002

During a 5-yr period, 1994-1998, pre-weaning and weaning data were collected on 591 calves produced by mating either straightbred Jersey, straightbred Limousin or $F_1$ (Limousin${\times}$Jersey) bulls to mature purebred Jersey or Limousin cows. Traits recorded included birth and weaning weight, height, length, girth, fat depth and a measure of muscle (ratio of stifle to hip width expressed as a percentage). All traits were analyzed assuming a model with sire and dam random effects that included effects of year and date of birth, sex, breed and year${\times}$sex interaction. Main effects were generally significant with few exceptions. Direct genetic effects were large for weight, height, girth and muscle with a breed trend from purebred Jersey (small) to purebred Limousin (large). At weaning, the maternal effect of the Jersey dam was positive for weight (10.9${\pm}$4.9 kg), girth (3.7${\pm}$1.0 cm) and muscle (6.0${\pm}$0.9%). Heterosis was highly significant and positive only for fat depth (1.5${\pm}$0.2 mm) with the $F_1$ progeny being the fattest, followed by the backcrosses, then purebred Jersey and purebred Limousin. Also, significant (p<0.001) but negative heterosis was observed for weight, girth and muscle. The change in ranking for fat depth relative to other traits is a reflection of the large heterotic effects relative to direct effects on fat depth. Epistatic effects were not significant on any trait at birth or weaning. This study has indicated the possibility of exploiting the positive heterotic and maternal effects for fat depth and muscularity to meet specific meat quality and quantity demand by consumers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.45-52
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• 1996

This study was conducted to know how cold tolerance of rice is inherited. Several crosses were made between cold tolerant and susceptible varieties, and their progenies were evaluated for days to heading, spikelet number per panicle and spikelet fertility under both cold water and natural conditions. In F$_1$ and F$_2$ generations, earlier heading, more number of spikelet per panicle and higher spikelet fertility under the cold condition were dominance, and less delay or reduction in heading days and spikelets per panicle by cold treatment were over dominance or partial dominance, while less reduction in spikelet fertility by cold-water irrigation was complete dominance. Heritability in most characters by cold treatment was high and there was less difference of heritabilities in heading days and spikelets per panicle between cold treatment and natural conditions, while there was much difference of heritability in spikelet fertility between two conditions. Heterosis in spikelet fertility was considerably high, while those in heading days and spikelets per panicle were relatively low. Heterosis in remote crosses was especially larger under the cold-water treatment condition compare with that under natural condition.

• Steel and Composite Structures
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• v.42 no.4
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• pp.427-446
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• 2022

Cutouts in the beams or plates are often unavoidable due to inspection, maintenance, ventilation, structural aesthetics purpose, and sometimes to lighten the structures. Therefore, there will be a substantial reduction in the strength of the structure due to the introduction of the cutouts. However, these cutouts can be reinforced with the different patterns of ribs (stiffener) to enhance the strength of the structure. The present study highlights the influence of the elliptical cutout reinforced with a different pattern of ribs on the stability performance of such stiffened composite panels subjected to non-uniform edge loads by employing the Finite element (FE) technique. In the present formulation, a 9-noded heterosis element is used to model the skin, and a 3-noded isoparametric beam element is used to simulate the rib that is attached around a cutout in different patterns. The displacement compatibility condition is employed between the plate and stiffener, and arbitrary orientations are taken care by introducing respective transformation matrices. The effect of shear deformation and rotary inertia are incorporated in the formulation. A new mesh configuration is developed to house the attached ribs around an elliptical cutout with different patterns. Initially, a study is performed on the panels with different stiffener schemes for various ply orientations and for different stiffener depth to width ratios (d_s/b_s) to determine an optimal stiffener configuration. Further, various parametric studies are conducted on an obtained optimal stiffened panel to understand the effect of cutout size, cutout orientation, panel aspect ratio, and boundary conditions. Finally, from the analysis, it can be observed that the arrangement of the stiffener attached to a panel has a major impact on the buckling capacity of the stiffened panel. The stiffener's depth to width ratio also significantly influences the buckling characteristic.