Predicted and realized gains of different selection strategies in soybean populations: a comparative study

Abstract

Genetic gains from selection on yield were predicted in three soybean populations using original data anddata corrected by the variation in agronomic traits of check cultivars. Predicted gains were compared to realizedgains after correction for agricultural season effects - caused by environmental differences during the predictionand checking growing seasons - to indicate the best selection strategy and check the influence on yield ofselection on the other traits assessed in the field. Individual selection, selection among and within families andcombined selection were used for grain yield alone and for simultaneous selection on grain yield, plant heightand number of days to maturity traits. Selection was made on F5 generation plants grown in an experimentalfield in Viçosa, Minas Gerais State during the 1997/98 agricultural season. The experiment used intercalatedcheck cultivars. The results indicated lower within family heritabilities compared to the other types. Littlevariation was detected in gain prediction due to data correction. At field level, simultaneous selection performedbetter for grain yield improvement. Simultaneous gains for number of pods per plant, number of seeds per podand mean weight of one seed, which are primary yield components, were obtained only when selection for thethree components was balanced.