diallel cross

{{Short description|Genetic model}}

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.Hallauer, A. R. and J. B. Miranda Filho. 1988 Quantitative genetics in maize breeding. 2nd ed. Iowa State University Press, Ames, IO.{{cite journal |author=Crusio WE, Kerbusch JM, van Abeelen JHF |title=The replicated diallel cross: a generalized method of analysis |journal=Behavior Genetics |volume=14 |issue=1 |pages=81–104 |date=January 1984 |pmid=6712552 |doi= 10.1007/BF01066070|s2cid=26899703 }}

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.{{Cite journal | doi = 10.1038/hdy.1965.12 | title = Analysis of variance of the half diallel table | year = 1965 | last1 = Jones | first1 = R. M. | journal = Heredity | volume = 20 | pages = 117–121 | issue=1| doi-access = free }} Full diallels require twice as many crosses and entries in experiments, but allow for testing for maternal and paternal effects.{{cite journal |author=Crusio WE |title=A note on the analysis of reciprocal effects in diallel crosses |journal=Journal of Genetics |volume=66 |issue=3 |pages=177–185 |date=December 1987 |doi= 10.1007/BF02927711|s2cid=35147905 |url=http://www.ias.ac.in/j_archive/jgenet/66/vol66contents.html |access-date=2009-08-14|url-access=subscription }} 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,Griffing, B. 1956. Concept of general and specific combining ability in relation to diallel crossing systems. Australian Journal of Biological Sciences 9: 463-493 estimate general or specific combining ability,Gardner, C. O. and S. A. Eberhart. 1966. Analysis and interpretation of the variety cross diallel and related populations. Biometrics 22: 439-452Sprague G. F., and L. A. Tatum. 1942. General vs. specific combining ability in single crosses of corn. J. Am. Soc. Agron. 34: 923-932 interactions with testing environments and years, or estimates of additive, dominant, and epistatic genetic effectsHayman, B. I. 1954. The analysis of variance of diallel tables. Biometrics 10: 235-244{{cite journal |author=Hayman BI |title=The theory and analysis of diallel crosses |journal=Genetics |volume=39 |issue=6 |pages=789–809 |date=November 1954 |doi=10.1093/genetics/39.6.789 |pmid=17247520 |pmc=1209689 |url=http://www.genetics.org/cgi/pmidlookup?view=long&pmid=17247520 |access-date=2010-03-02}} and genetic correlations.{{cite journal |author=Crusio WE |title=Bi- and multivariate analyses of diallel crosses: a tool for the genetic dissection of neurobehavioral phenotypes |journal=Behavior Genetics |volume=23 |issue=1 |pages=59–67 |date=January 1993 |pmid=8476392 |doi= 10.1007/BF01067554|s2cid=37158435 }}