• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.84-88
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• 1984

To obtain basic information on the breeding of early maturing, short plant height rapeseed varieties, the following 7 varieties, Isuzu, Miyuki, Norin 25, Rang, Yongdang, Cresus and Tower were used in diallel crosses in 1979. Maturing date, plant height and grain weight per plant for the parents, $F_1$'s and $F_2$'s of the 7 x 7 partial diallel crosses were measured in 1981 for analysis of their genetic behavior. The results obtained are summarized as follows: 1. The days to maturing of $F_1$'s showed complete dominance for early maturing, and both additive and dominance genetic variances were significant. Number of effective factors in $F_1$'s was 3, but in $F_2$'s was 1. The degree of dominance in $F_1$'s was partial, while in $F_2$'s was complete. Both broad and narrow sense herita-bilities in $F_1$'s was high, while in $F_2$'s was low. 2. Yield per plant in $F_2$'s was controlled by additive component of genetic variance only, but $F_1$'s was different. The degree of dominance in $F_1$'s was complete, while in $F_2$'s was partial. The direction of dominance showed almost complete dominance over high yield and three effective factors was estimated. Yield per plant was controlled by recessive genes. 3. The plant height was controlled by both dominance and additive variance. Dominance was directed toward tall plant height. Number of effective factors was 2, and broad and narrow sense heritability were high in the plant height.

• Korean Journal of Poultry Science
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• v.7 no.1
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• pp.31-42
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• 1980

In order to identify the best superior cross combination of breeder stocks for broiler production, combining ability test and analyses of phenotypic performances for parent stocks were examined on records of 1,440 broiler chicken which were produced from 4 parental strains and 3 maternal strains at Hanhyup Poultry Breeding Farm from September 28, 1978 to January 5, 1979. The results obtained were as follows; 1. There was not found heterosis effect in viability but it seems to be desirable to select Hubbard strain in paternal line to improve viability. 2. As the paternal and maternal lines, selection of Ross strain showed the best paternal and maternal performance and the best general combining ability in body weight at 8 weeks of age is expected to be able to improve body weight of it s crossbred And the most superior cross combinations based on the specific combining ability and performance of rack crossbred were identified as Hubbard x Ross ana Ross x Hypeco crossbreds. 3. The best paternal and maternal lines on the smallest feed consumption for 8 weeks were Hubbard and Ross strains, and Hypeco strain, respectively. Especially Hubbard x Hypeco cross combination was proved as the smallest feed consumption compared with other cross combinations. 4. In feed requirement per Kg body weight increase, Hubbard strain for paternal line, Hypeco strain for naternal line, and cross combinations of Hubbard x Hypeco, Hubbard x Ross and Ross x Hypeco were certified as the most superiors. 5. Also superior cross combinations of Hubbard x Hypeco and Hubbard x Ross earned the most profit per bird through economic analysis. According to results as shown above, this experiment seems to be able to reach a such conclusion that production of superior cross combinations Hubbard x Ross, Hubbard x Hypeco and Ross x Hypeco through selection of Ross and Hubbard strains to paternal line and Hypeco and Ross strains for maternal line may become to considerable improvement for important economic characters of broiler; viability, body weight, feed consumption and feed requirement.