• KOREAN JOURNAL OF CROP SCIENCE
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• v.4 no.1
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• pp.31-71
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• 1968

To clarify the breeding behavior of the hybrids between tropical and temperate area rice varieties, investigations were made on heading days and grain sterility. In this study, crosses were made in half way diallel involving 7 varieties: 2 photoperied sensitive Indicas, 2 less sensitive intermediate Indicas, 1 Ponlai Japonica and 2 high temperature sensitive Japonicas. The parents and $F_1$s were grown under 10 hours and 14 hours daylength controlled conditions at both IRRI(International Rice Research Institute, N$14^{\circ}$17') and Suwon(N$37^{\circ}$16'). F2s with their parents were grown at IRRI in the short day season, and at Suwon under natural conditions. Fa lines with their parents were grown at Suwon under natural conditions. Observations were made for heading days and sterility. The results are summarized as follow; 1. Heading days : 1. For the $F_1$s, earliness showed dominance or overdominance to lateness under the 10 hours condition, and dominance or partial dominance under the 14 hours conditions, at both IRRI and Suwon. 2. For the $F_2$s grown at IRRI during the shortday season earliness appeared to be dominant over lateness and segregation was not distinct and continuous. In the early season culture of $F_2$s at Suwon earliness showed partial dominance or was intermediate. In the proper season culture of $F_2$s lateness showed partial dominance or was intermediate. 3. In the combinations between late parental varieties which do not head at Suwon, transgressive segregants bearing effective panicles were obtained. 4. The crosses of parental varieties having long basic vegetative growth duration showed bigger variance in heading days, and significant correlation was found between of parental varieties and the mean coefficient of variance for parental arrays. 5. The means of heading days of F2 populations were significantly correlated with those of $F_1$ or mid-parents. The means of F 8 lines were also highly correlated with the means of $F_2$s, but, the means of $F_3$ lines grown at Suwon and of their parental $F_2$ individual, grown at IRRI were not correlated. 6. A faint heritability was calculated from the regression of $F_3$ lines grown at Suwon on the $F_2$ individuals grown at IRRI for most combinations, especially in the combinations involving shortday sensitive varieties. This implies low efficiency for the selection of heading days of $F_2$ individuals at IRRI to be grown in lines at Suwon. 7. No significant reciprocal effects were measured for $F_1$ and $F_2$ mean heading days. 8. Partitioning the observed photoperiod sensitivity. into two components, parental array mean md the deviation from this array mean, the parental photoperiod sensitivity contributing to the hybrids was measured in terms of general and specific combining ability for photoperiod sensitivity. 9. The photoperiod sensitivity of $F_1$s was higher than that of the parents, and it decreased as the generation progressed in most combinations of tested varieties. 10. The response of heading days to difference of temperature was weaker for $F_1$ hybrids than for the parents. The differences of temperature responses between the longday and shortday treatments were specific for the variety. 2. Sterility : 1. The $F_1$ sterility was specific for the combinations and not correlated to the parental sterility. The sterility of $F_1$s grown under the 10 hours condition was higher than of those grown under 14 hours. These results were the same at both locations, IRRI and Suwon. 2. The high sterile combinations in $F_1$ showed high sterility in $F_2$. The combinations between a high photoperiod sensitive variety and a high temperature sensitive variety showed high sterility and wider variance. 3. The mean sterility of $F_2$s was lower than of $F_1$s and the mean of $F_3$ lines was lower than of $F_2$s. Sterility decreased as the generation progressed, and the differences of $F_3$ sterility of different combinations were not significant. 4. A faint correlation between grain sterility and pollen sterility was observed in $F_2$ populations. 5. No significant reciprocal effects were measured in $F_1$ and $F_2$ sterility. 6. Following Griffing's method, specific combining ability effects were higher than general combining ability effects, especially in the combinations between highly photoperiod sensitive varieties and highly temperature sensitive varieties. 7. No distinct correlations were found between $F_2$ individual sterility grown at IRRI and $F_3$ line sterility grown at Suwon. 8. No distinct correlations were observed between heading days and sterility of $F_2$ individuals.

• Journal of Life Science
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• v.13 no.1
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• pp.29-33
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• 2003

The study was conducted to get genetic information on quantitative characters of $F_1$ in barley through diallel crosses using seven malting barley. The results obtained were summarized as follows. Additive, dominant, maternal, and reciprocal effort were observed in culm length, spike length, awn length, culm diameter, grain length, grain width, ]lumber of grains per spike, and 1000 grain weight. Based on the Vr-Wr graphical analysis, culm length, spike length, awn length, grain length, and number of grains per spike were found to be inherited over dominance. Dominant effects were higher than additive effects in culm length, spike length, awn length, culm diameter, grain length, grain width, number of grains per spike, and 1000 grain weight. The narrow- sense heritability showed high value as 40.06% for spike length.

• Journal of Sericultural and Entomological Science
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• v.35 no.2
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• pp.100-104
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• 1993

The genetics analysis for weight of matured silkworm(WMS) and number of eggs produced per moth(NEM) was studied by the seven parents diallel. Mean squares of additive effect, dominant effect, maternal effect and reciprocal effect were significant for two characters observed. The component of genetic variance analysis for WMS and NEM showed that dominant effect was higher than additive effect. Narrow sense heritability(h2ns) estimates were 0.773 and 0.228, in the WMS and NEM. The estimate of broad sense heritability(h2bs) value was higher than that of h2ns because of the low importance of dominance effect. Incomplete dominance was shown by Vr-Wr graphic analysis in the weight of matured silkworm and overdominance in the number of eggs produced per moth. In general combining ability effect, Jam 107 and Jam 124 was showed positively high for WMS and Jam 107 and S1 was expressed positively high for NEM. In specific combining ability effect, hybrids in S1XC51, S1XJam124 and Jam 107XJam 108 were exhibited positively high for WMS and Jam 107XN63, S1XC51, N74XJam 108 and Jam 107XJam 108 were found positively high for NEM.

• 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.

• Journal of Life Science
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• v.12 no.2
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• pp.213-218
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• 2002

The experiment was conducted to get basic information for cotton breeding program through four-variety diallel cross population. Additive, dominant, maternal, and reciprocal effect were observed significantly for days to maturity. Based on the Vr-Wr graphical analysis, the characters, number of bolls per plant, boll weight, seed and lint weight per boll, lint weight per boll, width of seed, 100-seed weight, days to flowering, and days to maturity were found to inherit incomplete dominance, and the characters of number of bolls per plant, width of seed, number of seeds per boll, and length of seed were assumed to inherit over dominance. The component of genetic variance analysis for boll weight, seed and lint weight per boll, lint weight per boll, number of seeds per boll, length of seed, and days to flowering showed that additive effects were higher than dominant effects. The narrow-sense heritability(h$_2$N) for boll weight, seed and lint weight per boll, lint weight per boll, days to flowering, and days to maturity showed high values as more than 43.19%. The estimate of broad-sense heritability(h$_2$B) value was higher than that of h$_2$N because of the low importance of dominance effects.