Researchers at Purdue University developed a soybean mutant with low phytate phosphorus and increased inorganic phosphorus. The objective of this study was to determine the inheritance of low phytate in a soybean line derived from the mutant. The procedure involved crossing the low-phytate line with a normal phytate line. Seed was harvested, replanted and assayed to identify the genes present in the various lines. The soybean breeders reported that low phytate was controlled by two recessive alleles (genes) designed as pha1 and pha2 at two independent loci. The importance of these studies is that we now know that both recessive alleles must be present to obtain low phytate seed. Developing soybean varieties containing double recessive genes is not easy for the soybean breeder.
Oltmans, S.E., W.R. Fehr, G.A. Welke and S.R. Cianzio. 2003. Inheritance of low-phytate phosphorus in soybean. Crop Sci. 44(2): 433-435.