Selection of superior genotype is one of the basic objectives of the plant breeding. To aid with this objective, plant breeders grow their crops across target environments. Understanding the pattern of response across these environments is an integral component of selection of superior and stable genotypes.
A set of multi-environment trials (MET) data from the national variety trial series grown over four years was taken from the Ethiopian barley breeding program; spanning stages from early generation to national variety trial testing for yield is used in this study. The trials were analysed in a linear mixed model framework, fitting a one-stage model for MET data including a correlated spatial process for field trend within each trial, and combining a factor analytic model for genotype by environment interaction effects.
The genetic correlations from this MET analysis were then used to cluster the environments based on their similarity. The stability of hybrid performance across these environmental clusters indicated broad (Bekoji-2005 and Bekoji-2004) and specific adaptation Sgonder-2007 and Sgonder-2006) of hybrids to certain types of environments. In addition, analysis of this historical MET data can also shed light on how breeding program design can be improved to capture response across the target population of environments, as it can inform the adequacy of the current number of barley suitable locations in Ethiopia.
Keywords: Barley MET; correlated environment; genotype by environment interaction