Potato improvement for tropical conditions: II. Selection indices and efficiency of indirect selection
Eduardo de Souza Lambert, César Augusto Brasil Pereira Pinto, and Cícero Beserra de Menezes
This study evaluated the efficiency of selection indices that can contribute to potato clone selection under favorable and stressful conditions as well as the possibility of indirect selection for heat tolerance. Among the selection indices, the arithmetic and geometric means and index 4 were the most appropriate. The susceptibility index and percentage of yield reduction indicate only specifically adapted clones. Indirect selection for heat tolerance is not suitable in view of the low correlation coefficient among clone means in the environments. Selection based on the overall environment mean is more fit to select broadly adapted genotypes. In general, clones that performed best under stress conditions and presented heat tolerance were specifically adapted, in spite of low performance means under favorable conditions. Well-adapted genotypes to both stress and favorable conditions can however be selected.