INHERITANCE OF ELEVATED PALMITIC ACID CONTENT IN SOYBEAN SEED OIL

Soybean [Glycine max (L.) Merr.] oil with an elevated palmitic acid content may be useful for production of some food and industrial products. Two mutant soybean lines with palmitic acid contents of > 180 g kg-1 were developed by treatment of 'A1937' seeds with N-nitroso-N-methylurea (NMU) and 'Elgin' seeds with ethyl methanesulfonate (EMS). The mutant lines, A1937NMU-85 and ElginEMS-421, were crossed to determine their genetic relationship for elevated palmitic acid content. The F2 and F3 generations were grown in the field and transgressive segregates with > 250 g kg-1 palmitic acid were obtained, the highest content known in soybean. The segregation ratios indicate that the two mutant lines have different alleles at two independent loci. A1937NMU-85 was crossed to C1727, a line with the fap2 allele that controls increased palmitic acid content. The lack of transgressive segregation in the F2 generation of the cross indicate that A1937NMU-85 and C1727 have alleles controlling high palmitic acid at the same locus or at tightly linked loci. The allele in A1937NMU-85 was designated fap2-b. The allele in ElginEMS-421 was given the temporary designation of fap?(ElginEMS-421) until its relationship to other alleles for modified palmitic acid content can be determined.