A0198
Title: Optimizing the allocation of trials to sub-regions in multi-environment crop variety testing for correlated genotypes
Authors: Maryna Prus - Hohenheim University (Germany) [presenting]
Abstract: New crop varieties are extensively tested in multi-environment trials in order to obtain a solid basis for recommendations to farmers. When the target population of environments is large, a division into sub-regions is often advantageous. If the same set of genotypes is tested in each of the sub-regions, a linear mixed model (LMM) may be fitted with random genotype-within-sub-region effects. The first analytical results for optimizing the allocation of trials (designs) to sub-regions have been obtained recently. The genotype effects were assumed to be uncorrelated. However, this assumption is not always suitable for practical situations. In praxis, genetic markers are often used in plant breeding to determine the genetic relationships of genotypes, which helps to model their correlation. A more general LMM with correlated genotype effects is considered. An analytical solution for the allocation of trials is proposed in the form of an optimality condition. For particular covariance structures of genotype effects, optimal designs are given explicitly.
