Fig 1. Cross validations performed to estimate the effect of population structure in genomic selection.

A. 2^nd cross validation strategy–Within-cluster cross validation formed by discriminant analysis of principal components (DAPC); B. Illustration of between-clusters cross validation for DAPC cluster 1: 3^rd cross-validation strategy–cross validation with training population composed of a third part of DAPC clusters 2–5 and validation in a third part of DAPC cluster 1 (1^stTP); 4^th cross-validation strategy–cross validation with the training population composed by a third part of three of the DAPC clusters (2^nd, 3^rd 4^th, and 5^th TPs). Therefore, the first training population (1^st TP) is formed from the four remaining DAPC clusters (3^rd cross validation strategy), while the second, third, fourth and fifth training populations (2^nd, 3^rd 4^th and 5^th TPs) were each created from only three of those four DAPC clusters (4^th cross validation strategy).