Genotype x Location Interaction Patterns and Testing Strategies for Oat in the Canadian Prairies

The Canadian Prairies is one of the most important oat (Avena sativa L.) production regions in the world and oat breeding objectives for the region include high grain yield, groat content, and dietary fiber concentration. Using data from the 2004 through 2009 Western Cooperative Oat Registration trials, we investigated yearly genotype x location interaction patterns for grain yield, groat percentage, and dietary fiber concentration and the relationships among these traits. Despite large hectareage and wide geographical range, the Canadian Prairies was found to be relatively homogeneous and can be regarded as a single mega-environment, with southern Manitoba tending to be slightly different from other portions of the region. Simulation indicated that three test locations could suffice to represent the region and provide reliable information for relative grain yield of differing genotypes. Groat percentage and dietary fiber content were more heritable than grain yield thus requiring fewer (no more than three) test locations for reliable selection. beta-glucan and total dietary fiber were closely correlated, thus the latter could potentially be improved via selecting for the former, which is simpler to determine, although more research is required in this area. However, dietary fiber content was negatively correlated with grain yield and/or groat content, constituting a challenge for breeding milling oats.