Molecular breeding of a high oleic acid soybean line by integrating natural variations

Abstract

Soybean is an important crop used for oil production. Alterations of the fatty acids, especially increased oleic acid content, can improve the nutritional quality and oxidative stability of soybean oil. During seed development, two genes, encoding FAD2-1A and FAD2-1B, are mainly responsible for the transformation from oleic acid to linoleic acid, and the combination of fad2-1a and fad2-1b is the key factor for increasing oleic acid content. To breed high oleic acid varieties, we analyzed the haplotype of FAD2-1A and FAD2-1B among 1250 soybean accessions and detected a novel mutation in the FAD2-1A gene that we described as fad2-1a/W254Stop. By focusing on the mutation fad2-1a/W254Stop and the reported fad2-1b allele, we developed two molecular markers. Based on these markers, we selected one line (435) from a cross between the fad2-1a(W254Stop) allele and the existing fad2-1 allele. The oleic acid content of ‘435’ was 91.03%. The ‘435’ line was used as a donor parent, and an elite soybean cultivar ‘Heinong51’ was selected as the recurrent parent. After three backcrosses, we detected an individual with high oleic acid content (75%) and high yield. We named this individual ‘Fuhang3’. This study generated material for breeding high oleic acid soybean varieties and improved the rate of breeding novel soybean varieties.