Comparison among direct, indirect and index selections on agronomic traits and nutritional quality traits in common bean

BACKGROUND: Selection indices are linear combinations that allow the selection of several characters simultaneously. The objective of this study was to verify the efficiency of direct selection, indirect selection and selection indices in the identification of higher inbred common bean lines for grain yield, morphological, phenological and nutritional traits. RESULTS: There is genetic variability for grain yield, lodging, general adaptation note, cycle, insertion of the first pod, calcium and iron concentrations in the seeds. Moderate phenotypic correlation coefficients were observed between grain yield and general adaptation note (r = 0.57) and cycle (r = 0.57). When direct selection was performed for grain yield, the insertion of the first pod, calcium and iron concentrations showed negative indirect selection gains. The classic index showed that the distribution of gains has become more balanced: grain yield (39.05%), calcium (8.29%) and iron concentration (1.64%). CONCLUSION: Direct selection and indirect selection are not efficient in the simultaneous selection of agronomic traits and nutritional quality in common bean. The classical, base and multiplicative indexes provide responses of gain balanced among traits and superior genetic progress in the selection of inbred common bean lines, and have a high coincidence between the lines selected. (c) 2012 Society of Chemical Industry