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Computer Simulation of Marker-Directed Population Improvement

A wide range of commercially important traits in forest tree breeding may be referred to as complex, where a situation-specific approach will make genetic improvement as efficient as possible. The most common approach in current programs is to treat all traits as purely polygenic, assuming the classical “infinitesimal model” (Fisher 1918). The objective of our research is to quantitatively evaluate breeding strategies using marker-directed population improvement (MDPI) (Nelson and Echt 2004). In these strategies, the complex nature of commercial traits is reflected in predicting both polygenic and quantitative trait loci (QTL) genetic effects, and combining these into a single selection criterion. We review here the development of the computer simulation model that will enable this research. With the help of the model, it is possible to assess impact of several parameters, such as the density and information content of markers flanking the QTL, and the relative effect of the QTL on the trait’s phenotype. The effects of these variables can be analyzed within the context of a regular recurrent selection strategy, where the main objective is the genetic response in a production population. Proportional reduction in gene diversity, cost, and time components can also be evaluated.


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Author(s): Milan Lstibůrek, C. Dana Nelson, C. S. Echt, T. J. "Tim" Mullin, Yousry A. El-Kassaby, R. Pong-Wong

Publication: Tree Improvement and Genetics - Southern Forest Tree Improvement Conference - 2007