Modelling spatial trends in sorghum breeding field trials using a two-dimensional P-spline mixed model

• DOI: 10.1007/s00122-017-2894-4
• Publication Date: 2017-04-03T22:01:52Z
• Authors: Julio G. Velazco; María Xosé Rodríg...; Martin P. Boer; David R. Jordan; Paul H. C. Eilers; Marcos Malosetti; Fred A. van Eeuwijk
• Keywords: Smoothing; Mixed model

A flexible and user-friendly spatial method called SpATS performed comparably to more elaborate trial-specific models in a series of sorghum breeding trials. Adjustment for trends plant field trials is essential efficient evaluation selection genotypes. Current mixed model methods analysis are based on multi-step modelling process where global local fitted after trying several candidate models. This paper reports the application novel that accounts all types continuous variation single step by fitting smooth surface. The uses two-dimensional P-splines with anisotropic smoothing formulated framework, referred as model. We applied this methodology large partially replicated new was assessed comparison standard use autoregressive correlation residuals. improvements precision predictions genotypic values produced were equivalent those obtained using best each trial. One advantage approach patterns trend genetic effects modelled simultaneously Furthermore, we used adequately adjust trends. strategy reduces potential parameter identification problems simplifies process. Therefore, should be considered an easy-to-use alternative routine analyses