Soybean [Glycine max (L.) Merr.] seed phosphorus is stored primarily as phytic acid, a form in which it is unavailable to monogastric mammals and birds. Because of the nutritional and environmental problems caused by phytic acid, development of cultivars with low phytic acid (lpa) mutations has become an important objective in many soybean breeding programs. Information about the inheritance of the low phytate trait would facilitate these efforts. The objectives of the current research were (i) to map low phytate loci in populations derived from the lpa mutant line CX1834-1-2, (ii) to identify closely linked molecular markers, and (iii) to characterize inheritance of the trait. We identified two loci associated with the low phytate phenotype of CX1834-1-2 and discovered an epistatic interaction between the loci. A locus on linkage group (LG) N near Satt237 accounted for 41% of the observed variation in seed inorganic phosphorous (Pi) levels, which are inversely correlated with phytate levels in plants carrying the lpa mutation. Another locus near Satt527 on LG L explained 11% of the variation in seed Pi levels, and an interaction between the LG L and N loci accounted for an additional 8 to 11%. The loci on LG N and LG L are probably the previously designated pha1 and pha2 loci.
ASJC Scopus subject areas
- Agronomy and Crop Science