Confirmation of molecular markers and agronomic traits associated with seed phytate content in two soybean RIL populations
The concentration of phytate is an important consideration when analyzing feed grain for livestock. Simple sequence repeat markers Satt237 and Satt561 were found to be linked to quantitative trait loci (QTLs) for phytate concentration in soybean [Glycine max (L.) Merr.] seed. Previous research also established a significant correlation between seed inorganic phosphorus (Pi) and seed phytate. The objectives of this study were to confirm these QTL in independent environments and populations, to compare the effectiveness of marker-assisted selection with that of phenotypic selection for low phytate, and to evaluate agronomic traits associated with low phytate soybean. The low phytate soybean mutant CX1834-1-2 was crossed with the cultivar 5601T and line S97-1688 to form two populations. The Satt237 marker was linked to a major QTL (R2 > 0.10) governing seed phytate, and Satt561 was linked to a minor QTL (R2 < 0.10) in both populations. These two confirmed QTL have been named cqPha-001 and cqPha-002. The phenotypic correlations were significant (P < 0.05) for plant height (r = 0.26), seed protein (r = –0.19), and seed oil (r = 0.17). Phenotypic selection was found to be more effective in lowering mean phytate levels and more cost efficient.