The Efficiency of Half-Sib, Half-Diallel and Circular Mating Designs in the Estimation of Genetic Parameters in Forestry: A Simulation
Abstract:A technique based on MIVQUE (minimum variance quadratic unbiased estimation) and the first approximation of the variance of a ratio was used to compare efficiency per unit observation in lowering the variance of estimation of three genetic ratios (single tree heritability, Type B correlation, and dominance-to-additive variance ratio). The efficiency comparisons were made over eight levels of genetic control for three mating designs (half-sib, half-diallel, and circular with four crosses per parent) with variable numbers of parents at two or five locations. The field design was held constant within a location as four randomized complete blocks with a six-tree row-plot per cross (full-sib designs) or per half-sib family (half-sib design). For heritability estimation the half-sib mating design is the most efficient over numbers of location and parents in seven of the eight levels of genetic control, and the circular design is more efficient over all levels examined than the half-diallel design. For estimation of Type B correlation the circular design is superior under five of the eight genetic control levels and superior for every case examined to the half-diallel design. In the remaining 3 Type B correlation estimation cases, the half-sib design is superior. For dominance-to-additive variance ratio estimation, the half-diallel design offers little, if any, advantages over the circular design. Optimal numbers of parents (highest efficiency) for a mating design exist only for the half-diallel design and optima are extant for all three genetic ratios. Optimal numbers of locations exist for all three mating designs and vary with mating design and level of genetic control. For. Sci. 38(4):757-776.
Document Type: Journal Article
Affiliations: Assistant Research Scientist, Department of Foresty, School of Forest Resources and Conservation, University of Florida
Publication date: November 1, 1992
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