Molecular genetic resources for development of 1% linolenic acid soybeans

Advanced plant breeding will incorporate the most efficient methods available to introgress new traits and develop improved crops. Molecular markers that are specifically targeted to desirable alleles are important molecular genetic resources for selection of traits. Reducing the amount of linolenic acid in soybeans [Glycine max (L.) Merr.] is a desired breeding objective so that oxidatively stable soybean oil can be produced without the production of trans fatty acids. The objective of this work was to determine the molecular genetic basis for soybeans containing 1% (10 g kg(-1)) linolenic acid in the seed oil fraction and to develop molecular markers specific for identified alleles. Utilizing the soybean homologs of Arabidopsis FAD3 as candidate genes, mutations were discovered in all three GmFAD3 genes in the soybean line A29. The mutations were associated with the linolenic acid phenotype in segregating populations. Molecular markers specific for the mutant alleles enabled capture of the phenotype. Novel combinations of mutant alleles at the three GmFAD3 loci allowed the development of new germplasm containing 1% linolenic acid in the seed oil along with SNP-based molecular markers that can be used in a backcross breeding strategy.