Estimation of variances of the effects of incomplete diallels using a matrix approach

• Autor(a) principal: de Assis, Giselle Mariano Lessa
• Data de Publicação: 2004
• Outros Autores: da Fonseca, Ricardo [UNESP], Cruz, Cosme Damião, Carneiro Jr., José Marques
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/S1415-47572004000300017; http://hdl.handle.net/11449/67992
• topic: General combining ability; Incomplete diallel; Specific combining ability; allele; analysis of covariance; analysis of variance; analytic method; analytical parameters; breeding method; controlled study; cross breeding; diallel analysis; gene expression; genotype; process model; statistical analysis

A matrix approach is described for assessing the variance of effects in incomplete diallels designs. The method is illustrated by reference to simulated complete and incomplete diallels using different combinations of constraints, average degree of dominance and, for the incomplete diallel, number of hybrids. Our results showed that caution should be taken in working with incomplete diallels under conditions of overdominance because there were changes in the rank of the genotypes when the excluded hybrid had parents with a low frequency of the favorable allele (i.e. the allele which increases expression of a character). The expression described in this paper is a rapid and safe approach to estimate variances and covariances of the effects of contrasts of incomplete diallels. Copyright by the Brazilian Society of Genetics.