General combining ability model for genomewide selection. Numerical approach suggested by griffing 1956 has been extensively used to determine the specific combining ability sca and general combining ability gca of lines derived from diallel cross. A study was undertaken to estimate general and specific combining in brinjal through diallel analysis involving 6 parents. Osprr37 and ghd7 are the major genes for general combining ability of dth, ph and spp in rice. General combining ability an overview sciencedirect topics. The estimated general combining ability gca, was found significant for plant. General combining ability effects were significant p ability is primarily a measure of additive effects, which are amenable toselection. The concepts of general combining ability gca and specific combining ability sca were first introduced by 2 in relation to corn breeding and have been expanded into animal breeding by 3 and others. General and specific combining ability for nine morphologic. The objectives of our study were i to quantify the importance of general combining ability gca and specific combining ability sca variances for seed yield, oil content and oil yield.
The interaction of general combining ability and locations was less than the variation in sca and locations. General combining ability effects were significant p combining ability effects were significantly highest in gg x fg genetic group. Pdf general combining ability gca, specific combining ability. Estimates of general combining ability gca and specific combining ability sca were obtained using an analysis of line x line. Combining ability of inbred lines of maize zea mays. Ijasr general and specific combining ability studies of. The general combining ability gca and specific combining ability sca effects of the single crosses entries were examined by drawing an average tester coordinate atc view for. Osprr37 and ghd7 are the major genes for general combining. In diallel analysis, using mixed models, it is possible to estimate the variance components of general combining ability gca, specific combining ability sca, reciprocal gca rgca, reciprocal sca rsca, and parents, even in unbalanced datasets. Pdf general combining ability gca, specific combining.
Estimates of general and specific combining ability for grain. Variations include half diallels with and without parents, omitting reciprocal crosses. Estimation of variance for reciprocal general and specific. The main objective of the present study was to investigate the magnitude of variance of general combining ability gca and specific combining ability sca effects and their interaction with. Specific combining ability an overview sciencedirect.
Estimation of general and specific combining ability in bread. Graduate thesis or dissertation estimation of general. Tambaqui showed higher general and specific combining abilities than the other groups for most of the variables, making it the most important genetic group. The challenge for a hybrid breeder is to allocate the test resources in a multistage selection program in an optimum. Analysis of general and specific combining abilities of. In the fi nal step, promising hybrid combinations are chosen based on both gca and specifi c combining ability sca eff ects. Griffing 1956 provided clear statements of methods of analysis of diallel crosses in terms of general and specific combining ability and the circumstances in which. Qtl mapping of combining ability and heterosis of agronomic. Full diallels require twice as many crosses and entries in. Concept of general and specific combining ability in. Combining ability and heterosis in maize zea mays l. Combining ability in crosses is defined as the ability of. General combining abilityaverage performance of each parent in a series of crosses. General combining ability specific combining ability gca is the average performance of a line in hybrid combinations.
Sca is to designate those cases in which certain combinations do relatively better or worse than would be expected on the basis of the average performance of the line involved. Combining ability of inbred lines of maize zea mays l. Its exceptional vigour resulted from high specific combining ability together with the good general combining ability of both its parents. General combining ability how is general combining ability. Griffing 2 defines diallel crosses in terms of genotypic values where the sum of general combining abilities for the two gametes is the breeding value of the cross i, j. This work supported use of a broadbase tester for preliminary screening for general combining ability, followed by testing in specific combinations. General combining ability model for genomewide selection in a biparental cross genomewide selection within an ab biparental cross is most advantageous if it could be effectively done before the cross is phenotyped. Our objectives were to determine if a general combining ability gca model is useful for genomewide selection in an ab cross, and to assess the influence of training population size n gca, n umber of crosses pooel d into the trani ni g population n. Abstract estimation of general and specific combining ability effects in a diallel analysis of cross. General combining ability model for genomewide selection in a.
Ratios of estimated gca to sc a for the traits diameter and volume were low 0. General combining ability gca, specific combining ability. General combining ability and specific combining ability were estimated for seed yield, head diameter, 1,000seed weight, plant height and oil content. The main objective was to estimate the effects of general combining ability gca of the lines, and the specific combining ability sca of their crosses and heterosis, to estimate its use in a breeding program. Principles and utilization of combining ability in plant. The combining ability analysis revealed highly significant differences among the treatments for all the parameters studied except days to 50% flowering and number of primary branches per plant. Interaction between the genotypes and environment was also determined among the crosses.
Ijasr general and specific combining ability studies. Combining ability for growth parameter and yield components were evaluated in a 7. General combining ability is primarily a measure of additive effects, which are amenable toselection. Relevance of specifi c versus general combining ability in winter wheat manje gowda, c. Relevance of specifi c versus general combining ability in. May 25, 2016 two concepts of general combining ability gca and specific combining ability sca have had important influence on inbred line evaluation and population development in crop breeding. Pdf general and specific combining ability for quantitative. Line 1 was the highest in general combining ability for carcass grade and percent kidney knob while line 3 was the greatest in general combining ability for fat thickness and percent fat trim, which was considered an undesirable trait. Average daily gain, body weight, combining abilities, rabbit, reciprocal effect. Pdf heterosis test and estimation of general and specific. Gca, specific combining ability sca semantic scholar.
In a factorial design either complete or not the general combining ability gca of a parent is its breeding value, while the specific combinig ability sca of a mating is the additional genetic value due to the interaction between those particular genotypes. Estimation of general and specific combining ability effects in a diallel analysis of crosspollinating populations, including the selfed parents, is presented in this. Combining ability ability of inbred lines to transmit desirable performance to the hybrid progeny. General combining ability gca and specific combining ability sca were determined for grain yield, height of the ear, plant height and disease scores using griffings method 1956. General and specific combining abilities famuviebreedr. General combining ability was defined as the average performance of a line in hybrid combinations, while specific combining ability referred to those cases in which certain. Relevance of specific versus general combining ability in. Specific and general combining ability for yield in. Torrie 1957, who determined general combining ability g. Pdf relevance of specific versus general combining ability. Griffings methods comparison for general and specific. Combining ability, heterosis and inbreeding depression. General and specific combining ability the biplot for grain yield data explained 76. Line 2 was the most effective in general combining ability for percent trimmed legs.
Polycross method tested lines are sown in spatial isolation of at least 3 km, in 4 repetitions, with 10 plants per repetition in a complete randomized block system to enable cross pollination between. Study on heterosis and combining ability linkedin slideshare. The main objective of the present study was to investigate the magnitude of variance of general combining ability gca and specific combining ability sca effects and their interaction with environments in wheat triticum aestivum l. Aug 20, 20 combining ability is one of the most important information breeders use to identify superior inbred lines on the basis of their performance in hybrid combinations. General combining ability gca and specific combining ability sca variances were estimated as measures of additive genetic and dominance variances respectively. Common analysis methods utilize general linear models to identify heterotic groups, estimate general or specific combining ability, interactions with testing environments and years, or estimates of additive, dominant, and epistatic genetic effects and genetic correlations. Our objectives were to determine if a general combining ability gca model is useful for genomewide selection in an ab. Diallel cross a type of crossing where every line is crossed with all possible combinations. Combining ability, maternal effects, and heritability of. Combining ability and diallel analysis the concepts of general and specific combining ability were precise ly formalized by sprague and tatum 1942. Combining ability and gene action estimates of eight parent.
Combining ability and heterosis in corn breeding lines to. This fullsib family also exhibited good stem straightness and excellent branching characterstics. The significance of general combining ability and special combining ability for most of the traits indicated the importance of both additive and nonadditive effects on expression levels. In these equations gi is the general combining ability denoted as g. Griffing 2 defines diallel crosses in terms of genotypic values where the sum of general combining abilities for the two gametes is the breeding value of the cross. Apr 19, 2012 in statistical terms, the general combining abilities are main effects and the specific combining ability is an interaction. Prediction of gene action and combining ability for yield. The combining ability analysis is an important tool for the selection of desirable parents together with information regarding nature and magnitude of controlling quantitative traits masood et al. The variance ofspecific combining ability oincludes the. Thus, the present study was designed to estimate the. It brings an introduction to combining ability and the concept of general and specific combining ability, methods for estimating combining ability, and qtl mapping of related traits. It is a wellestablished fact that appropriate choice of parental this is very important for success. General and specific combining ability for quantitative. The combining ability of sunflower inbred lines is mostly tested in the s 4 generation, although early testing of combining ability after the first generation of selfpollination was found to be good for identification of lines with good combining ability shein, 1978.
A major step in evaluating the type of tester to be used was the development of the concept of general and specific combining ability sprague and tatum, 1942. A detailed examination of the concept of combining ability in relation to diallel crossing systems is made. The results revealed that mean squares for gca were highly significant for head diameter and significant for yield and oil content. In statistical terms, the general combining abilities are main effects and the specific combining ability is an interaction. The present study was carried out to investigate the diallel analysis in upland cotton gossypium hirsutum l. Prediction of gene action and combining ability for yield and. A diallel cross is a mating scheme used by plant and animal breeders, as well as geneticists, to investigate the genetic underpinnings of quantitative traits in a full diallel, all parents are crossed to make hybrids in all possible combinations. Principles and utilization of combining ability in plant breeding. The general combining ability is most important for two generations, is highly significant for the two stages, and is more important than specific combining ability. Graduate thesis or dissertation estimation of general and. Combining ability is one of the powerful tools in identifying best combiners which may be hybridized either to exploit heterotic or to accumulate fixable genes additive. Two concepts of general combining ability gca and specific combining ability sca have had important influence on inbred line evaluation and population development in crop breeding. Evaluation of general and specific combining ability in a.
Combining ability analysis analysis of variance for line x tester without checks was performed to estimate general combining ability gca and specific combining ability sca effects based on the method described by singh and chaudhary, 1985. An analysis was conducted on ear weight data using griffings method 2, model i to deter mine general and specific combining ability effects. General combining ability gca, specific combining ability sca and reciprocal efects on average daily gain in body weights at various ages of rabbit in. There are four main types of diallel mating design. Thus, use inbred lines with good combining ability for yield and yieldcontributing characters to form excellent combinations is crucial. Specific combining ability an overview sciencedirect topics. The term general combining ability gca is associated with genes of additive effects, used to designate the average. The study of agronomic characters of healthy and virus diseased plants in a diallel cross program concerning five different varieties of bean, shows that in both cases the general combining ability for yield and its components usually has positive or negative significant values. Combining ability and gene action estimates of eight. General and specific combining ability in serrasalmidae. General combining ability makes a greater contribution to phenotypic variance than specific combining ability for most variables, indicating a predominance of genes with an additive effect. General combining ability gca is directly related to the breeding value of a parent and is associated with additive genetic effects, while specific.
The variation in specific combining ability of a line was not related to the magnitude of its gca effect. The cross between clones 96 and 55 was the best of the 16 crosses tested. General combining ability is most commonly tested by polycross and topcross methods, and specific combining ability is tested by diallel crosses. General combining ability is most commonly tested by polycross and topcross.
560 1540 1329 111 386 537 1220 1058 199 900 1501 173 731 1542 915 1074 747 45 1307 817 1388 998 1179 874 1261 239 6 829 561 1476 1290