Variability Within and Among F1 Families from Diverse Three‐Parent Soybean Crosses1

Abstract

In three‐parent crosses, gametes produced by the F1 of the two‐parent cross differ genetically. Therefore, variability will exist among families derived from different F1s of the three‐parent crosses. The objective of this study was to determine the relative variability for agronomic characteristics among and within different F1 families from crosses involving plant introductions and cultivars. Four lines within each of 20 F1 families from each of two three‐parent soybean [Glycine max( L) Merr.] crosses ([cultivars ✕ plant introductions] ✕ cultivars) were evaluated for 2 years at West Lafayette, IN. Differences among F1 family means were significant for seed yield, date of maturity, lodging, and plant height. Variability among lines within families was at least 1.4 times as great as variability among families for all characteristics except maturity in one cross. In both crosses the highest yielding 10% of the lines were from different F1 families than the lowest yielding 10% of the lines. In one cross, lines witht he earliest maturity, shortest plant height, and lowest lodging scores all came from different F1 families than lines with late maturity, tall plants, and high lodgings cores. In the second cross one family contained lines in both the highest and lowest 10% of the population for maturity and lodging scores. Two families contained lines in both the highest and lowest 10% of the population for plant height. The data suggest there maybe merit in maintaining the identity of lines from individual F1s in diverse three‐parent crosses. Selection for individual lines could then be concentrated in those families with high mean performance for specific characteristics.