Environmental Effects on Soybean with Modified Phosphorus and Sugar Composition

Development of soybeans [Glycine max (L.) Merr.] with modified phosphorus (P) and sugar composition adds value to soybean meal. The identification and release of the soybean line V99‐5089 with a mutation in the D‐myo‐inositol 3‐phosphate synthase 1 gene (MIPS1) provides a germplasm source that dually enhances both P and sugar composition of soybeans. An evaluation of the recombinant inbred line population from the cross of V99‐5089 × Essex was completed at three environments in 2 yr. Phenotypic selection for modified composition was slightly more effective than marker‐assisted selection with the Satt453 marker, which was 87% efficient. In the mutant lines, a significant genotype × environment interaction was shown for inorganic phosphorus (Pi) concentration but not sugar concentration. Correlations for improving P and sugar composition were favorable, and with the exception of emergence there were no strong correlations with agronomic traits. The correlation of emergence with Pi was significant (r = −0.59), indicating reduced emergence due to the mutation. Reduced emergence is a problem in low phytate germplasm generally and further research is necessary to genetically improve emergence of low phytate lines.