• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.63-72
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• 2006

Parthenogenesis, the development of unfertilized ovum opens new perspectives in silkworm breeding in the development of homozygous breeds. In order to improve induction of artificial parthenogenesis in the excised unfertilized eggs of different breeds of the silkworm, Bombyx mori L., a new method was devised and the results were compared with the routine method. General and specific combining abilities and hybrid vigour of newly developed bivoltine breeds were analyzed utilizing bivoltine breeds viz., $CSR_2,\;CSR_4,\;CSR_{17}\;and\;NB_4D_2$ Estimation of GCA revealed superiority of the breeds, $DNB_1$ for eight characters followed by $DNB_4$ for five characters. Among the testers, $CSR_2$ was found good general combiner for seven characters followed by $CSR_{17}$ for four characters. A great deal of variations was observed among the hybrids studied. Five hybrids namely, $DNB_1{\times}CSR_2,\;DNB_4{\times}CSR_4,\;DNB_4{\times}NB_4D_2,\;DNB_6{\times}CSR_2\;and\;DNB_7{\times}CSR_2$ showed significant SCA effects for 5-6 characters. The hybrid, $DNB_4{\times}CSR_4$ showed its superiority by expressing significant hybrid vigour over BPV for 7 characters. Majority of the hybrids exhibited significant hybrid vigour for survival rate, yield/10,000 larvae by weight, cocoon weight, cocoon shell weight, filament length and denier.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.119-123
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• 1986

The study was conducted to find out the gene effects on body weights at weaning and at the age of 60 days in mice, with 343 progenies from full-dialell crosses of four lines of BALB/c, CBA, C3H and C57BL. The progenies were reared at the Experimental Animal Farm, College of Agriculture, Kyungpook National University from November, 1984 to February, 1985, and data collected from the progenies were analyzed into general combining ability, maternal effects, specific combining ability and reciprocal effects with Harvey's model. General combining ability effects estimated in line-crosses were -0.6033~0.5298 for weaning weights and -0.5086~1.0012 for body weights at the age of 60 days. General combining ability for BALB/c and C57BL were significantly better than general combining ability for CBA and C3H for both traits (P<0.05). Maternal effects for C3H were significantly larger than the maternal effects of BALB/c for both traits (P<0.05). The estimates of maternal effects were -0.9678~0.4609 for weaning weights and -1.1886~0.0729 for body weights at the age of 60 days. Specific combining ability effects were estimated to be significant (P<0.05), and the estimates were -0.1999~0.3380 for weaning weights and -0.4056~0.3317 for body weights at the age of 60 days. Reciprocal effects were found to be largest in BALB/c${\times}$C57BL and BALB/c${\times}$C3H. The estimates were -0.5049 from BALB/c${\times}$C57BL and 0.4972 from BALB/c${\times}$C3H form weaning weights, and -1.0336 from BALB/c${\times}$C57BL and 1.2793 from BALB/c${\times}$C3H for body weights at the age of 60 days.

• Journal of Sericultural and Entomological Science
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• v.29 no.1
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• pp.31-38
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• 1987

The genetic analysis was caried out on the boiling-off ratio of cocoon layer, and the amounts of sericin and fibroin in the F1 generation from the diallel crosses of silkworm. The result obtained were as follows : 1. Boiling-off ratio and the amounts of sericin adn fibroin in male and female were over dominqnce and partial dominance, respectively. 2. The additive effect of gene was higher then the dominance effect in the amounts of sericin and fibroin in male and female, and in boiling off ration in female. 3. The direction of dominance in the amounts of sericin and fibroin in male and female was positive and that in boiling off ratio negative. 4. The effect of three characters on the combining ability was significant and their general combining ability was higher than the specific combining ability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.250-256
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• 1992

This study was carried out to obtain basic genetic informations in pea(Pisum sativum L.). A series of field experiments were carried out with seven pea cultivars and F$_1$ hybrids for three years. Based on the information collected from a set of diallel crosses, the behaviours of inheritance of seed yield and ten major agronomical characters were observed by the estimation of heterosis and combining ability. Heterosis for seed yield per plant was 79% and those for yield components such as number of seeds per plant, number of pods per plant, stem length, stem diameter, number of branches per plant, also showed relatively high values. General combining ability(GCA) and specific combining ability(SCA) were significantly different among major agronomic characters, and the variances of GCA were higher than those of SCA latter. Among the tested cultivars, Alderman was found to be the most promising parent based upon the GCA effects on the seed yield and yield components. The crosses of Sugar Ann$\times$Alderman, Wando$\times$Alderman and JI 1198$\times$Chinju ＃6, showed the highest SCA effects on seed yield and yield components.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.7-14
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• 2006

A breeding programme was initiated during 2001 to introduce sex-limited larval markings to a productive multivoltine breed - BL67 from an inbred sex-limited line, MY1 (SL) maintained at Central Sericultural Research and Training Institute, Mysore. Introgressive hybridization, recurrent backcrossing for six generations followed by sib-mating resulted in synthesis of a new multivoltine silkworm breed BL67 (SL) with sex-limited larval markings. The new breed was studied for combining ability by crossing with eight bivoltine breeds viz., $NB_4D_2,\;CSR_2,\;CSR_2 (SL),\;CSR_2,\;CSR_4,\;CSR_8,\;CSR_{18}\;and\;CSR_{19}$. General combining ability effects of the new breed showed its superiority over the popular Pure Mysore by expressing significant GCA effects for six out of twelve characters whereas the results are on par with the original multivoltine breed. The hybrid $BL67(SL){\times}CSR2(SL)$ excelled in several quantitative characters such as pupation rate (90.2%), cocoon weight (1.97 g), cocoon shell weight (40 cg), cocoon shell ratio (20.3%), filament length (918 m), denier (2.96), raw silk percentage (14.96%) and neatness (90 p). Studies on cocoon size variability revealed that the cocoons of $BL67(SL){\times}CSR2(SL)$ were found comparatively uniform showing less standard deviation of 6.55 and co-efficient of variation of 3.91 %. The suitability of newly developed breed for easy grain age operation and commercial exploitation with promising hybrid have been discussed.

• Journal of the Korean Society of Tobacco Science
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• v.4 no.1
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• pp.7-13
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• 1982

Six orient varieties of N.tabacum and 15 $F_1$ hybrids, not including reciprocal crosses, were evaluated for the degrees of heterosis and the combining abilities of 6 characteristics in Suweon, Korea, 1981. The values 9f general combining abilities tiers greater than those of specific combining abilities in all traits but significant SCA was also observed for Plant height, days to flowering and yield. In general, CCA effect was large in Samsun, Kavala and Izmir varieties. Large SCA values were observed for number of leaves in Samsun x Izmir, days to flowering in Samsun x Serves, leaf shape in Basma x Xantlli, and yield in Basma x Kavala and Xanthi x Izmir. Heterosis of favorable directions in $F_1$ was generally observed for all traits. Especially the $F_1$ of Samsun x Kavala flowered earlier than its midparents. Large heterosis effects were manifested for the number of leaves in Samsun x Izmir and yield in Samsun x Izmir as well as Xanthix Izmir.

• Proceedings of the Korean Reliability Society Conference
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• 2002.06a
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• pp.411-414
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• 2002

A class of block designs for general combining ability comparisons within two groups of inbred lines in diallel crosses is given. Use is made of balanced block designs obtained by cyclically developing a single initial block.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.426-433
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• 1986

This experiment was carried out to investigate the competitive ability and the interaction of each species in ten mono-and binary-associations of four forage species; orchardgrass, tall fescus, ladino clover, and alfalfa. Each species was grown in intra- and interspecific stands in large pots for one year. And samplings of shoot and root were taken in Spring, Summer, and fall clipping stages. Intra- and interspecific competition was compared and evaluated by expected yield, aggressivity, relative yield total(RYT), compensation index(CI), general combining ability(GCA), and specific combining ability (SCA) with shoot and root dry matter production of each species in monoculture and binary mixture. The forage yield was high in two grass species and the mixture of them, but low in two legume species and the mixture of them. The mixture of tall fescue-ladino clover was evaluated as a productive association with a high PYT(1.05) and a high SCA(0.79), and tall fescue was a more aggressive species in it. Each of grass-grass and legume-legume mixture was less aggressive between two species and lower SCAs than grass-legume mixtures. Especially, orchardgrass was the most agressive species and alfalfa was the least, but tall fescue had the highest GCA and ladino clover had the lowest in shoot competition. Also in root, tall fescue- ladino clover mixture was a good match with a high RYT(l.12) and a high SCA (0.60), and orchardgrass was highest in aggressivity. However, orchardgrass had the highest GCA in root while tall fescue had the highest in shoot.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.107-112
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• 2004

The combining abilities in the 5 newly evolved thermo tolerant breeds viz., SR6, SR7, SR8 SR9 and SR10 of silkworm Bombyx mori L. and their 15 hybrids were made in a line${\times}$tester crossing programme. Data were analysed for seven quantitative traits i.e., pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage under optimum room temperature $(25{\pm}{1^{\circ}C})$ conditions (In case of high temperature $(36{\pm}{1^{\circ}C})$ stress conditions five economic traits except filament length and raw silk percentage) with 3 widely adapted testers i.e., KA, CSR2 and CC1 as lines (females) and testers (males) respectively. The performance at high temperature and low humidity conditions aye only taken into consideration for selecting the best lines/hybrids. Among the lines SR6 exhibited positive General combining ability (GCA) effects for pupation rate, cocoon yield, cocoon weight and cocoon shell ratio traits, followed by SR7 for pupation rate, cocoon yield and cocoon shell weight and cocoon shell ratio. Among testers, KA exhibited positive GCA effects for two quantitative traits cocoon yield, cocoon weight and CSR2 for cocoon shell weight and cocoon shell ratio under adverse temperature conditions. The hybrid SR6${\times}$CC1 and SR7${\times}$CSR2 exhibited significant positive Specific combining ability (SCA) effects for majority of the traits in high temperature stress conditions of rearing. The better parent value of heterosis(Heterobeltiosis) was exhibited by the hybrid SR6${\times}$CC1 for pupation rate, cocoon yield, cocoon weight and cocoon shell weight and SR7${\times}$CSR2 for all the trails evaluated under high temperature conditions. Based on the results, the lines SR6 and SR7 was judged as best combiners and the hybrids SR6${\times}$CC1 and SR7${\times}$CSR2 can be selected for commercial exploitation in tropical climate.

• Korean Journal of Poultry Science
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• v.10 no.2
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• pp.83-89
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• 1983

Sixteen crosses from two strains of White Cornish and White Plymouth Rock were reared seperately on floors and abdominal fat was measured every two weeks interval from two weeks to twelve weeks of age. The abdominal fat weights surgically removed were slightly heavier in female than male. Estimates of general combining ability variances of body weight showed significant at all weeks of age in both sexes but those of abdominal fat weight were significant at 2, 8, 10 and 12 weeks of age in female and 2, 6 and 12 weeks of age in male. In percentage of abdominal fat to body weight, the significant differences were observed at 10 and 12 weeks of age only in female. The specific combining ability variances were significant at 4, 6, 10 and 12 weeks of age in female and 4, 8 and 12 weeks of age in male in body weight. In abdominal fat weight, there were significant differences at 4, 8, 10 and 12 weeks of age in female but no significant differences in male. The specific combining ability variances of percentage of abdominal fat to body weight showed significant differences at 4 and 8 weeks of age in female but no significant difference in male.