Diallel cross

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.^[1][2]

In a full diallel, all parents are crossed to make hybrids in all possible combinations. Variations include half diallels with and without parents, omitting reciprocal crosses.^[3] Full diallels require twice as many crosses and entries in experiments, but allow for testing for maternal and paternal effects.^[4] If such "reciprocal" effects are assumed to be negligible, then a half diallel without reciprocals can be effective.

Common analysis methods utilize general linear models to identify heterotic groups,^[5] estimate general or specific combining ability,^[6][7] interactions with testing environments and years, or estimates of additive, dominant, and epistatic genetic effects^[8][9] and genetic correlations.^[10]

There are four main types of diallel mating design:

1. Full diallel in which parents and reciprocal crosses are involved along with F1
2. Full diallel without inclusion of parents
3. Half diallel with parent and without reciprocal crosses
4. Half diallel without parents or reciprocal crosses

References

1. ^ Hallauer, A. R. and J. B. Miranda Filho. 1988 Quantitative genetics in maize breeding. 2nd ed. Iowa State University Press, Ames, IO.
2. ^ Crusio WE, Kerbusch JM, van Abeelen JHF (January 1984). "The replicated diallel cross: a generalized method of analysis". Behavior Genetics 14 (1): 81–104. doi:10.1007/BF01066070. PMID 6712552. 
3. ^ Jones, R. M. (1965). "Analysis of variance of the half diallel table". Heredity 20 (1): 117–121. doi:10.1038/hdy.1965.12.  edit
4. ^ Crusio WE (December 1987). "A note on the analysis of reciprocal effects in diallel crosses". Journal of Genetics 66 (3): 177–185. doi:10.1007/BF02927711. http://www.ias.ac.in/j_archive/jgenet/66/vol66contents.html. Retrieved 2009-08-14. 
5. ^ Griffing, B. 1956. Concept of general and specific combining ability in relation to diallel crossing systems. Australian Journal of Biological Sciences 9: 463-493
6. ^ Gardner, C. O. and S. A. Eberhart. 1966. Analysis and interpretation of the variety cross diallel and related populations. Biometrics 22: 439-452
7. ^ Sprague G. F., and L. A. Tatum. 1942. General vs. specific combining ability in single crosses of corn. J. Am. Soc. Agron. 34: 923-932
8. ^ Hayman, B. I. 1954. The analysis of variance of diallel tables. Biometrics 10: 235-244
9. ^ Hayman BI (November 1954). "The theory and analysis of diallel crosses". Genetics 39 (6): 789–809. PMC 1209689. PMID 17247520. http://www.genetics.org/cgi/pmidlookup?view=long&pmid=17247520. Retrieved 2010-03-02. 
10. ^ Crusio WE (January 1993). "Bi- and multivariate analyses of diallel crosses: a tool for the genetic dissection of neurobehavioral phenotypes". Behavior Genetics 23 (1): 59–67. doi:10.1007/BF01067554. PMID 8476392.