scholarly journals Influence of additive and non-additive gene effects on body measurements in the domestic rabbit

2021 ◽  
Vol 35 (1) ◽  
pp. 1-8
Author(s):  
V. N. Obasi ◽  
S. N. Ibe
Keyword(s):  
Combining Ability ◽  
Growth Parameters ◽  
Tail Length ◽  
Body Measurements ◽  
Additive Effects ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Domestic Rabbit ◽  
Genetically Improved ◽  
Additive Gene

General Combining Ability (GCA) and Specific Combining Ability (SCA) were used to determine the influence of additive and non-additive gene effects on growth parameters, using 2 kits produced in full diallel crosses involving three breeds of rabbits namely, New Zealand White (NZW), Dutch (DT) and Chinchilla (CH). GCA was significant (P<0.05) for four out of the twelve traits studied, namely Body length (BL), Heart girth (HG), Ear length (EL) and Tail Length (TL). GCA values ranged from-12.594 for body weight (BWT) to 0.041 for the length of the hind limb (LHL) for NZW, -3.836 for BWT 10 0.123 for Head Circumference (HC) for DT and -0.035 for Head-to-shoulder (HS) and 16.431 for BWT for Chinchilla. SCA was significant (P<0.05) for HS only. SCA estimates ranged from -0.016 (BWT) to 0.187 (HG), 1.018 (BL) to 10.22 (BWT) and -17.09 (LHL) to 7.354 (BWT). for NZW x DT, NZW x CH and DTX CH crosses, respectively. The significant GCH observed in the four growth parameters indicates that genes governing them aci mainly additively. This implies that they may be genetically improved by selection and pure breeding. Significant SCA for HS is an indication that genes governing this character impart non-additive effects, suggesting that improvement could be brought about by exploiting crossbreeding and by improving the environment.

Estimating the heritability of butterfat production

1961 ◽  
Vol 57 (3) ◽  
pp. 289-294 ◽  
Author(s):  
S. R. Searle
Keyword(s):  
Genetic Variation ◽  
New Zealand ◽  
Dairy Cows ◽  
Total Variance ◽  
Additive Effects ◽  
Narrow Sense ◽  
Sampling Errors ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene

Part of the variation among butterfat yields in dairy cows arises from genetic differences among the animals. The proportion which this bears to the total variance is known as heritability. In the ‘narrow’ sense it is defined (Lush, 1940), as the proportion of the total variance that is due to additive gene effects; the ‘broad’ sense definition includes genetic variation arising from non-additive gene effects as well as that due to additive effects. Since related animals have a proportion of their genes in common the covariance among their production records can be used for estimating genetic variation and hence heritability. This paper discusses three groups of related animals most frequently used for this purpose, twins, daughter-dam pairs and paternal half-sibs, and presents the results of analysing production records of artificially bred heifers in New Zealand, including evidence of the magnitude of the sampling errors of the heritability estimates.

Combining Ability Estimates in Heat Tolerant Tomato (Solanum lycopersicum L.) Genotypes

2010 ◽  
pp. 113-120
Author(s):  
S Ahmad ◽  
AKM Quamruzzaman ◽  
M Nazim Uddin
Keyword(s):  
Combining Ability ◽  
Agricultural Research ◽  
Relative Magnitude ◽  
Fruit Weight ◽  
Research Centre ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Component Traits ◽  
Additive Gene ◽  
Tomato Genotype

The experiment was conducted at the experimental farm of Olericulture Division, Horticulture Research Centre, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur from May to August 2003. Combining ability effects were estimated for yield and component traits in a 8 x 8 diallel design excluding reciprocals in tomato. The variances for general combining ability (GCA) and specific combining ability (SCA) were highly significant indicating the presence of additive as well as non-additive gene effects in the traits studied. The relative magnitude of these variances indicated that additive gene effects were more prominent for all the characters under study. The tomato genotype P1 (TM051) proved to be the best general combiner for yield followed by P2 (TM053) and the combinations P1xP3, P1xP5 and P5xP7 were identified as the best specific combiner for earliness, yield per plant, number of fruits per plant and individual fruit weight.

scholarly journals Combining capacity and heterosis in eggplant hybrids under high temperatures

2019 ◽  
Vol 37 (3) ◽  
pp. 348-353
Author(s):  
Ricardo de N Valadares ◽  
Danieli A Nóbrega ◽  
Lilian B de Lima ◽  
Jordana Antônia dos S Silva ◽  
Ana Maria M dos Santos ◽  
...  
Keyword(s):  
High Temperatures ◽  
Combining Ability ◽  
Phenotypic Variability ◽  
Pollen Viability ◽  
Fixation Index ◽  
Gene Effects ◽  
F1 Hybrid ◽  
Fruit Length ◽  
Additive Gene Effects ◽  
Additive Gene

ABSTRACT The objective of this work was to estimate the combinatorial capacity and heterosis of eggplant hybrids under high temperature conditions. Seven genitors, twelve hybrid combinations, originated from a partial diallel, and the Ciça F1 hybrid, as control, were evaluated. The experiment was conducted under greenhouse conditions in randomized block design with four replications, from April to December 2017. The assessed traits related to high temperatures were pollen viability (PV) and fruit fixation index (FFI); the morphoagronomic traits were number of fruits per plant (NFP), fruit weight (FWe), production per plant (PP), fruit length (FL), fruit width (FWi), fruit length/width ratio (FLWR) and plant height (PH). The variance analysis showed greater participation of the additive gene effects in relation to the non-additive gene effects in most traits, except for PV. The genitors CNPH 141, CNPH 135, CNPH 109 and CNPH 51 stood out with favorable gene effects to obtain genotypes tolerant to high temperatures, since they present good general combining ability (GCA) for the traits FFI, NFP and PP. The 1x4 and 3x4 hybrids presented positive estimates for both GCA and specific combining ability (SCA), demonstrating a greater potential to be used in breeding to increase the FFI, NFP and PP, under high temperatures. The 1x4, 1x5 and 1x6 hybrids expressed positive heterosis for most analyzed traits. The 1x4 hybrid stood out for the highest averages for PV, FFI, NFP and PP. For FWe, FL, FWi and FLWR, both positive and negative heterosis were observed, as consequence of the phenotypic variability of the genitors for these traits and suggests the possibility of selection for different sizes and formats.

scholarly journals Analysis of Combining Ability in Rice Varieties for Quantitative Traits

2019 ◽  
Vol 11 (3) ◽  
pp. 436-439
Author(s):  
Ghaffar KIANI
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Agronomic Traits ◽  
Block Design ◽  
Rice Varieties ◽  
Gene Effects ◽  
Breeding Programs ◽  
Grain Length ◽  
Additive Gene Effects ◽  
Additive Gene

Rice is staple food in Iran. Despite of high quality of local rice, their grain yield is low. In hybridization breeding programs, selection of suitable parents is an essential role for developing new combinations with broadens genetic diversity. Combining ability of local rice varieties namely ‘Hashemi’, ‘Sang Jo’ and ‘Tarom Deylamani’ and ‘Nemat’ was evaluated in a partial diallele analysis for agronomic traits in a randomized complete block design at Sari Agricultural Sciences and Natural Resources University. General combining ability (GCA) and specific combining ability (SCA) variances showed predominated role of additive gene effects in the inheritance of grain length. Both additive and non-additive components of genetic variances were important in the inheritance of traits like grain yield, plant height, panicle length, total grains per panicle, grain length and grain length to width. However, non-additive gene effects were seen for tiller number. Results showed that ‘Nemat’ was the best general combiner for most of characters followed by ‘Tarom Deylamani’. The cross of ‘Hashemi’ × ‘Tarom Deylamani’ was suggested to exploitation of heterosis breeding for increasing yield and its components in rice breeding programs. 

scholarly journals Study on combining ability and heterosis for earliness and short statured plant in maize

2016 ◽  
Vol 41 (2) ◽  
pp. 365-376 ◽  
Author(s):  
M Hoque ◽  
F Akhter ◽  
M Kadir ◽  
HA Begum ◽  
S Ahmed
Keyword(s):  
Combining Ability ◽  
Gene Action ◽  
Growth Parameters ◽  
Thousand Grain Weight ◽  
Gene Effects ◽  
Combining Ability Analysis ◽  
Additive Gene ◽  
Ear Height ◽  
Low X ◽  
Average Average

An experiment was carried out in 6x6 diallel crosses for combining ability analysis for grain yield, maturity and growth parameters in maize. Analysis of variance for combining ability showed that mean square value due to GCA & SCA were highly significant for all characters except SCA in days to tasseling and days to maturity indicated that all but two traits were governed by both additive and non-additive gene action. Variances due to GCA were much higher in magnitude than SCA indicated additive gene effects were much more important for all characters except cob length, thousand grain weight and ear height. The Parent P5 was the best general combiner for yield and most of the yield contributing characters. The Parent P1 & P2 were best general combiner for both dwarf and earliness. The crosses showing significant SCA effects for yield involving average x average, average x low and low x low general combining parents. The crosses P3xP6 & P4xP5 showed either significantly or numerically higher heterosis than checks BHM-5, BHM- 7 & BHM-9 for yield.Bangladesh J. Agril. Res. 41(2): 365-376, June 2016

scholarly journals The combining ability of new lines of cucumber for the main economically valuable traits

2020 ◽  
pp. 58-61
Author(s):  
A. M. Borasulov ◽  
M. H. Aramov ◽  
F. H. Abdullayev ◽  
R. F. Mavlyanova
Keyword(s):  
Combining Ability ◽  
Early Stage ◽  
Dominant Role ◽  
Fruit Weight ◽  
Special Role ◽  
Initial Material ◽  
Gene Effects ◽  
Epistatic Effects ◽  
Additive Gene Effects ◽  
Additive Gene

Relevance. To create heterotic cucumber hybrids, it is important to have a high general and specific combining ability of the initial material, which makes it possible to select valuable genotypes at an early stage of selection. Material and methods. The research was carried out in 2018-2020. at the Research Institute of Vegetable, Melon Crops and Potatoes, located in the Tashkent region of Uzbekistan (SRIVMC&P). Studied 6 accessions of cucumber. As a result of diallelic crosses, 36 hybrid combinations were obtained (p2). Hybridological analysis was carried out according to the first Griffing's method, including forward and backcrossing and the use of parental forms (p2). To determine the combining ability, conventional methodologies were used (1,15). Genetic-statistical analyzes were carried out using the MS Excel application package. Results. Studies have established that according to the traits "the number of days from seed germination to the opening of female flowers" and "the number of days until the technical ripeness of fruits" in all studied cucumber accessions, the ratio (σ 2ĝi<σ 2si) is observed, where the dominant role in the inheritance of this trait also belongs to genes with dominant and epistatic effects. The trait “number of fruits per plant” is controlled by dominant and epistatic gene effects (σ 2ĝi<σ 2si) in almost all cucumber accessions, and in the accession A-6 - by additive gene effects (σ 2ĝi <σ 2si). The phenomenon (σ 2ĝi <σ 2si) was noted for the trait "average fruit weight", where the expression of the trait is controlled by the dominant and epistatic effects of genes (σ 2ĝi <σ 2si) in three studied cucumber accessions (C-25/1, A-6 and A-9), and in the other three accessions, additive gene effects (σ 2ĝi <σ 2si) are more important in inheritance. The trait "productivity of one plant" is controlled by the dominant and epistatic effects of genes (σ 2ĝi <σ 2si) in the three studied cucumber accessions, and in the other three accessions (C-25/1, A-6 and A-9), genes play a special role for the expression of the trait with additive effects. Promising hybrid combinations with the best performance for their use as a initial material for breeding have been revealed.

GENE EFFECTS IN CORN (ZEA MAYS L.): II. RELATIVE IMPORTANCE OF GENE EFFECTS FOR PLANT HEIGHT AND CERTAIN COMPONENT ATTRIBUTES OF YIELD

1962 ◽  
Vol 42 (2) ◽  
pp. 349-358 ◽  
Author(s):  
E. E. Gamble
Keyword(s):  
Plant Height ◽  
Seed Weight ◽  
Zea Mays L ◽  
Inbred Lines ◽  
Relative Importance ◽  
Additive Effects ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene ◽  
Kernel Row Number

Estimates of mean effects, additive, dominance, additive × additive, additive × dominance, and dominance × dominance gene effects were obtained for 15 crosses from 6 inbred lines of corn for each of the following attributes: plant height, kernel row number, ear length, ear diameter, and seed weight.All the gene effects were found to contribute to inheritance of the attributes in the crosses studied. However, not all gene effects are present in all crosses. Mean effects were the most important contributors to the inheritance of the attributes. Of the gene effects, the dominance gene effects were the most important contributors to the inheritance of the attributes except for kernel row number. Additive, dominance and epistatic gene effects appear to contribute more or less equally to the inheritance of kernel row number. Additive gene effects were more important for these attributes than for yield. They were relatively more important for kernel row number, ear diameter, and seed weight than for plant height and ear length.Epistatic gene effects were relatively more important than additive gene effects but less important than dominance gene effects for the material studied. For the attributes studied the additive × dominance and dominance × dominance gene effects were somewhat more important contributors to inheritance than the additive × additive effects.

scholarly journals Combining Ability of Quality Protein Maize Inbred Lines for Yield and Morpho-Agronomic Traits under Optimum as Well as Combined Drought and Heat-Stressed Conditions

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 184 ◽  
Author(s):  
Nyasha E. Chiuta ◽  
Charles S. Mutengwa
Keyword(s):  
Heat Stress ◽  
Combining Ability ◽  
Agronomic Traits ◽  
Inbred Lines ◽  
Sub Saharan Africa ◽  
Optimum Conditions ◽  
Gene Effects ◽  
Additive Gene Effects ◽  
Additive Gene ◽  
Drought And Heat Stress

Drought and heat stress have perceptibly become major maize (Zea mays L.) yield reducing factors in Sub-Saharan Africa. As such, the objectives of this study were to: (i) determine the type of gene action conditioning tolerance to combined drought and heat stress (CDHS), and (ii) identify inbred lines with good combining ability for yield and other morpho-agronomic traits under CDHS. Twenty-four single cross hybrids (SCHs) obtained from crossing 10 inbred lines in a 4 × 6 North Carolina Design II, and a drought-tolerant check, were evaluated under CDHS and optimum conditions in the field. The experiment was laid out in a 5 × 5 alpha lattice incomplete block design, replicated three times. Additive gene effects influenced all the traits under CDHS except grain yield, which was influenced by non-additive gene effects. A preponderance of additive genetic effects was observed for all traits recorded under optimum conditions. Inbred lines L30, L6, L5, L17 and L2 showed good combining ability for yield under CDHS, indicating that they could be good parental lines in hybridization programs. Based on the results, SCHs L2*30, L6*13 and L5*18 exhibited high specific combining ability (SCA) effects for yield under CDHS. These hybrids are recommended for further multi-locational evaluation to determine the stability of their performance.

scholarly journals DIALLEL ANALYSIS OF RESISTANCE TO BACTERIAL STALK ROT (Pectobacterium chrysanthemi pv. zeae Burk., McFad. and Dim.) IN CORN (Zea mays L.)

2016 ◽  
Vol 8 (2) ◽  
pp. 48 ◽  
Author(s):  
Nuning A. Subekti ◽  
Artemio M. Salazar
Keyword(s):  
Disease Resistance ◽  
Combining Ability ◽  
Diallel Analysis ◽  
The Philippines ◽  
Effective Control ◽  
Gene Effects ◽  
Stalk Rot ◽  
Additive Gene Effects ◽  
Pectobacterium Chrysanthemi ◽  
Additive Gene

One of the major disease problems affecting maize farming in the Philippines is bacterial stalk rot (BSR) caused by Pectobacterium chrysanthemi pv. zeae Burk., McFad. and Dim., which is formerly known as Erwinia chrysanthemi. The annual loss due to BSR is estimated at PhP. 20 million equivalent to Rp3.5 billion. At present, there is no effective control method against BSR and, therefore, varietal improvement through breeding resistant germplasms is needed. The present study aimed to determine the combining ability and the extent of additive and non-additive genetic effects in corn inbred lines with a range of reaction to BSR. Four resistant lines (S3YB 137-1-1-B, TUPI (S3) 5-1-B, TUPI (S3) 15-2-B, and 97-835) and two susceptible lines (CML 295 and 97-733) were used as genetic materials. Generation of test entries and evaluation of disease resistance were conducted at the experimental farm station of University of the Philippines Los Banos and Institute of Plant Breeding Los Banos, respectively, during 2002 to 2003 wet seasons. Griffing’s diallel mating system Model 1, Method 1 was followed in generating the test entries to make a total of 36 entries (six selfed parental lines and 15 each of F1 crosses and their reciprocal<br />crosses). The entries were then evaluated for disease resistance in a yield trial following a randomized complete block design (RCBD) with two replications. Results of diallel analysis<br />showed two lines, S3YB 137-1-1-B and TUPI (S3) 5-1-B, exhibited the best general combining ability (GCA) for resistance to BSR, while the crosses S3YB 137-1-1-B x TUPI (S3) 5-1-B and TUPI (S3) 5-1-B x 97-835 performed the best specific combining ability (SCA) for the resistance. GCA effect was greater than that of SCA. This indicated that additive gene effects were found to be more important than non-additive gene effects in the expression of resistance to BSR in the six corn lines used. Therefore, breeding programs towards recurrent selection that emphasize GCA would be more appropriate for<br />BSR resistance improvement involving those six lines.

scholarly journals DIALLEL ANALYSIS OF RESISTANCE TO BACTERIAL STALK ROT (Pectobacterium chrysanthemi pv. zeae Burk., McFad. and Dim.) IN CORN (Zea mays L.)

2016 ◽  
Vol 8 (2) ◽  
pp. 48
Author(s):  
Nuning A. Subekti ◽  
Artemio M. Salazar
Keyword(s):  
Disease Resistance ◽  
Combining Ability ◽  
Diallel Analysis ◽  
The Philippines ◽  
Effective Control ◽  
Gene Effects ◽  
Stalk Rot ◽  
Additive Gene Effects ◽  
Pectobacterium Chrysanthemi ◽  
Additive Gene

One of the major disease problems affecting maize farming in the Philippines is bacterial stalk rot (BSR) caused by Pectobacterium chrysanthemi pv. zeae Burk., McFad. and Dim., which is formerly known as Erwinia chrysanthemi. The annual loss due to BSR is estimated at PhP. 20 million equivalent to Rp3.5 billion. At present, there is no effective control method against BSR and, therefore, varietal improvement through breeding resistant germplasms is needed. The present study aimed to determine the combining ability and the extent of additive and non-additive genetic effects in corn inbred lines with a range of reaction to BSR. Four resistant lines (S3YB 137-1-1-B, TUPI (S3) 5-1-B, TUPI (S3) 15-2-B, and 97-835) and two susceptible lines (CML 295 and 97-733) were used as genetic materials. Generation of test entries and evaluation of disease resistance were conducted at the experimental farm station of University of the Philippines Los Banos and Institute of Plant Breeding Los Banos, respectively, during 2002 to 2003 wet seasons. Griffing’s diallel mating system Model 1, Method 1 was followed in generating the test entries to make a total of 36 entries (six selfed parental lines and 15 each of F1 crosses and their reciprocal<br />crosses). The entries were then evaluated for disease resistance in a yield trial following a randomized complete block design (RCBD) with two replications. Results of diallel analysis<br />showed two lines, S3YB 137-1-1-B and TUPI (S3) 5-1-B, exhibited the best general combining ability (GCA) for resistance to BSR, while the crosses S3YB 137-1-1-B x TUPI (S3) 5-1-B and TUPI (S3) 5-1-B x 97-835 performed the best specific combining ability (SCA) for the resistance. GCA effect was greater than that of SCA. This indicated that additive gene effects were found to be more important than non-additive gene effects in the expression of resistance to BSR in the six corn lines used. Therefore, breeding programs towards recurrent selection that emphasize GCA would be more appropriate for<br />BSR resistance improvement involving those six lines.

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