• Journal of Life Science
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• v.10 no.2
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• pp.177-181
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• 2000

This study was conducted to estimate the genetic parameters such as combining ability, heritabilities and correlation coefficients forsome agronomic characters by 6$\times$6 dialled crosses of barley. The results obtained were summarized as follows. Mean squares of general combining ability(GCA) and specific combining ability(SCA) were significant for all characters observed. Mean squares of general combining ability for all characters were expressed as higher values than those of specific combining ability. Jecheon #5 showed the high general combining ability effects for culm length, and Waegwanpimack #1 showed the highest general combining ability effects for tiller number. Cygne also showed the high general combining ability effects for spike length and 1,000 grains weight. Furthermore, Plumage was expressed with the highest general combining ability effects for spike length and 1,000 grains weight. Furthermore, Plumage was expressed with the highest general combining ability effects for number of grains per spike. In specific combining ability effects, Samdugjeonbug # 45$\times$Plumage showed the high value for culm length, and Suwon #6 $\times$Waegwanpimack #1$\times$ was expressed with the highest specific combining ability effects for tiller number. Jecheon #5$\times$Plumage also showed the high specific combining ability effects for spike length and number of grains per spike. Suwon #6$\times$Cygne showed the high specific combining ability effects for 1,000 grains weight. The heritabilities of spike length an number of grains per spike were over 90%. In correlation coefficients among characters, relationships between culm length and tiller number, culm length and spike length, culm length and 1,000 grains weight, and spike length and 1,000 grains weight showed highly positively correlation.

• Journal of Sericultural and Entomological Science
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• v.28 no.2
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• pp.28-34
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• 1986

The general combining ability (GCV), the specific combining ability (SCA) and the reciprocal combining ability (RCA) effects wereobtained by 8$\times$8 diallel crosses of the silkworms with four Japanese races and four Chinese races, total eight lines. The result are as follows ; 1. The general combining ability (GVA) effects appeared high significant level in the total and the fifth instar periods (TP, FP), a female and a male cocoon weights (FW, MW), a female and a male cocoon layer weights (FL, ML) and a female and a male cocoon layer ratios (FR, MR). Only the reciprocal combining ability (RCA) effects appeared high significant level in the total and the fifth instar periods (TP, FP). 2. The Japanese original silkworm lines varied in the general combining ability effects from -0.864 to 0.578, and the Chinese original silkworm lines did in ones from -0.570 to 1.018. 3. The specific combining ability effects of the silkworm lines made in order of the crossing types of JL (Japanese lines) $\times$CL (Chinese lines)>CL$\times$JL>JL$\times$JL> CL$\times$CL in a total cocoon weights and a cocoon layer weights. 4. The reciprocal combining ability effects of the silkworm lines was in order of the crossing types of JL$\times$CL>JL$\times$JL> CL$\times$CL>CL$\times$JL in a total cocoon weights and cocoon layer weights.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.153-157
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• 2005

Recently two breeding programs were carried out for isolation of new parental inbred lines in Iran. This study was undertaken in order to estimate the combining ability effects and heterosis of these lines. For this purpose an $8\times8$ diallel cross analysis including eight inbred lines of silkworm with four lines from each program were studied for their five quantitative traits. The results indicated that reciprocal effects appeared insignificant for most of traits. Japanese lines of 111 and 113 were best combiners for shell weight, cocoon weight and shell percentage traits. With respect to pupation rate, Chinese line 110 was the best and according to general combining ability (GCA) and specific combining ability (SCA) variances, it is superior in specific combinations. Hybrid $109\times110$ showed better characters for both productive and viability traits. Hybrids with high heterosis had high SCA too.

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.1-14
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• 1986

The subject of this study was to obtain some genetic information for developing superior layer chickens. Heterosis and combining ability effects were estimated with 5,759 progenies of full diallel crosses of 6 strains in White Leghorn. Fertility, hatchability, brooder-house viability, rearing- house viability, laying-house viability, age at 1st egg laying, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion were investigated and analyzed into heterosis effect, general combining ability, specific combining ability and reciprocal effect by Grilling's model I. The results obtained were summarized as follows; 1. The general performance of each traits was 94.76% in fertility, 74.05% in hatchability, 97.47% in brooder-house viability, 99.72% in rearing-house viability, 93.81% in laying-house viability, 150 day in the age at 1st egg laying, 1,505g in the body weight at 1st egg laying, 60.08g in average egg weight, 77.11% in hen-day egg production, 269.8 eggs in hen-housed egg Production, and 2.44 in feed conversion. 2. The heterosis effects were estimated to -0.66%, 9.58%, 0.26%, 1.83%, -3.87%, 3.63%, 0.96%, 4.23%, 6.4%, and -0.8%, in fertility, hatchability, brooder-house viability, laying-house viability, the age at 1st egg laying, the body weight at 1st egg laying, average egg weight, hen-day egg Production, hen-housed egg production and feed conversion, respectively. 3. The results obtained from analysis of combining ability were as follows ; 1) Estimates of general combining ability, specific combining ability and reciprocal effects were not high in fertility. It was considered that fertility was mainly affected by environmental factors. In the hatchability, the general combining ability was more important than specific combining ability and reciprocal effects, and the superior strains were K and V which the additive genetic effects were very high. 2) In the brooder-house viability and laying-house viability, specific combining ability and reciprocal effects appeared to be important and the combinations of K${\times}$A and A${\times}$K were very superior. 3) In the feed conversion and average egg weight, general combining ability was more important compared with specific combining ability and reciprocal effects. On the basis of combining ability the superior strains were F, K and B in feed conversion, F and B in the average egg weight. 4) General combining ability, specific combining ability and reciprocal effects were important in the age at 1st egg laying and the combination of V ${\times}$F, F${\times}$K and B${\times}$F were very useful on the basis of these effects. In the body weight at 1st egg laying, general combining ability was more important than specific combining ability and reciprocal effects, relatively. The K, F and E strains were recommended to develop the light strain in the body weight at 1st egg laying. 5) General combining ability, specific combining ability and reciprocal effects were important in the hen-day egg production and hen-housed egg production. The combinations of F${\times}$K, A${\times}$K, and K${\times}$A were proper for developing these traits. 4. In general, high general combining ability effects were estimated for hatchability, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion and high specific combining ability effects for brooder-house viability, laying house viability, age at 1st egg laying, hen-day egg production and hen-housed egg production, and high reciprocal effects for the age at 1st egg laying.

• International Journal of Industrial Entomology and Biomaterials
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• v.24 no.1
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• pp.7-16
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• 2012

To meet the local requirement i.e. the tropical stress of Andhra Pradesh and marginal farmers, twenty four new hybrid combinations were tested in Line x Tester method involving eight newly developed polyvoltine oval lines viz., MSO1, MSO2, MSO3, MSO4, MSO5, MSO6, MSO7 and MSO8 and three bivoltine silkworm breeds viz., APS12, APS45 and APS8 as testers. These hybrids were reared to evaluate their performance. Data for eight economically important metric traits viz., fecundity, cocoon yield per 10,000 larvae by number, cocoon yield per 10,000 larvae by weight, survival rate, cocoon weight, cocoon shell weight, cocoon shell ratio and filament length was recorded. General combining ability (gca), specific combining ability (sca) and heterosis were analyzed. Further, the relative merit of the hybrids for all the traits under study was also assessed adopting Evaluation Index method. Based on combining ability effects, heterosis and evaluation index, five hybrid combinations viz., MSO3 $\times$ APS45, MSO1 $\times$ APS12, MSO7 $\times$ APS8, MSO2 $\times$ APS45 and MSO1 $\times$ APS45 were selected for further evaluation in different seasons.

• Journal of the Korean Society of Tobacco Science
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• v.5 no.2
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• pp.39-46
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• 1983

In order to obtain the basic information for the most successful breeding of Burley tobacco, these studies were performed on the correlations among agronomic characters and on the heterosis and combining ability in $F_1$ generation. Heterosis ratio was highly variable in different $F_1$ combinations. Positive heterosis was observed in all characters except days to flowering and yield showed the highest heterosis ratio. As the results of analysis of dialled table, the general combining ability (GCA) in all characters was shown to be significant . All characters except the number of leaves in the specific combining ability (SCA) were significant, Variety, L8, contributed negative GCA for all characters. Burley 21, ky 10 and ky 14 contributed negative GCA for leaf width, quality and yield, respectively. Hybrid of ky 10 x ky 14 showed negative SCA and hybrids of ky I0x L8 and ky 14 x L8 showed positive SCA for all characters. There were significant correlations between yield and number of leaves, leaf length, leaf width or leaf area. Correlation between yield and days to flowering was non- significant .

• International Journal of Industrial Entomology and Biomaterials
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• v.6 no.2
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• pp.107-113
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• 2003

Analysis of combining ability is a widely used biometrical tool to select promising parents and hybrids, to determine the kinds and relative magnitudes of genetic variability among hybrids as well as to forecast yield attributes in early breeding generations both in plants and animals. Various statistical approaches like Jinks and Hayman (1953), Griffing (1956), Kempthorne (1957) etc. have been extensively applied in plants. These approaches have also been tried in the mulberry silkworm, Bombyx mori L. In the present review, an attempt has been made to collect most of the studies carried out on combining ability in silkworm at one place and make it available to the scientists engaged in sericultural research.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.1
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• pp.3-11
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• 1984

In order to obtain the basic information for the successful breeding of aromatic tobacco (Nicotiana tabacum L.), the heterosis, combining ability and gene distributions in 28 Fl hybrids by diallel crosses between Korea local and Oriental varieties were investigated. The yield were higher, stalk height, leaf length and leaf width were larger and days to flower was shorter for the Fl hybrids when compared to mid-parent. Estimates of general combining ability were significant for all characters investigated, and specific combining ability were significant for yield, stalk height, leaves Per Plant, leaf width and days to flower. In vr-wr graph, partial dominane was exhibited by all characters investigated.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.3
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• pp.270-274
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• 1997

This experiment was conducted to evaluate the combining ability of japonica rices for improving the salinity tolerance at seedling stage. Nine varieties used in partial diallel analysis included three varieties of each tolerant, moderately tolerant and susceptible one. Twelve-day-old seedlings were grown in saline solution, initially at an EC of 6 dS /m for four days, followed by an EC of 12 dS /m for 20 days. The agronomic characters at seedling stage such as plant height, dry shoot weight and dry root weight were measured to analyze for combining ability of the parents. General combining ability(GCA) and specific combining ability(SCA) effects were highly significant for all tested parameters. However, mean squares for GCA were about five times larger than that for SCA suggesting the preponderance of additive gene action. Among tolerant varieties, Gaori and Namyang 7 were good combiner for improving the salinity tolerance at seedling stage in GCA as well as SCA.