Comparison of Three Procedures for Early Generation Testing of Soybean

Abstract

Early generation testing as a breeding procedure for autogamous crops consists of testing heterogeneous families, followed by selection of homozygous lines from superior families. Although early generation testing has been compared with other breeding methods, there have been few comparisons of different early generation testing procedures. Our objective was to assess the effectiveness of testing F1‐, F2‐, and F3‐derived families in soybean [Glycine max (L.) Merr.]. We applied the three procedures to two soybean populations from 1986 to 1993. Selected lines (F3‐, F4‐, and F5‐derived, respectively) were obtained by applying each testing method to each population. Divided into maturity classes, these selected lines were compared with unselected lines of the same generation, population, and maturity to determine genetic gain. The three early generation treatments produced similar genetic gains in seed yield, averaging approximately 4%. Selection of F1‐derived families for yield increased plant height and lodging, but the other two selection procedures were satisfactory in this respect. To maximize genetic gain for yield while avoiding undesirable changes in lodging in an early‐generation testing program, we recommend testing F2‐derived families, unless off‐season nurseries permit development of F3‐derived families without further loss of time.