Combined BLUP selection indexes with parents and F2 populations in soybean (Glycine max) breeding

Abstract

This study aimed to apply selection indexes in situations in which F 2 populations and their parents are evaluated simultaneously in field trials to predict population genotypic values and selecting the best populations. Fifteen F 2 soybean populations were evaluated for number of days to flowering and to maturity and grain yield. The data was analyzed using restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) to obtain genotypic effects, variance components and accuracies. Four selection methods were compared: genotypic values of the F 2 populations (g F2 ), combined index with the mean genotypic value of parents and F 2 population (I a ) and two indexes that add (to g F2 and to I a ) and consider genetic variability within populations (I b and I c ). The index I a presented a result similar to that obtained with the g F2 selection method. Selection indexes (I b and I c ) based on several sources of information were more efficient than selection based on g F2 values only.