Influence of genotype and environment on isoflavone contents of soybean

Isoflavones in soybean [Glycine max (L.) Merr.] may have positive imparts o n human health. The objective of this study was to determine the role of th e genotype, environment, and genotype x environment interactions on isoflav one contents of soybean. Nine isoflavones were measured in six cultivars gr own at eight locations during 2 yr The mean contents of total isoflavones a nd six of nine individual isoflavones were significantly higher in 1996 tha n 1995. There were significant differences among locations in one or more S ears for total and individual isoflavone contents. The gear x location inte ractions were significant due to changes in rank and magnitude among the lo cations during the 2 yr The genotype genotype x gear, genotype x location, and genotype)( year x location interactions were significant for total and individual isoflavone contents. Despite the significant genotype : environm ent interactions, the differences between the cultivars with the highest an d lo est total and individual isoflavone contents were relatively consisten t among the 16 environments. It should he possible to breed for isoflavone content as a quantitative trait in a cultivar development program.