Flanking SNP markers for vicine-convicine concentration in faba bean (Vicia faba L.)

The pyrimidine glycosides, vicine and convicine, limit the use of faba bean (Vicia faba L.) as food and feed. A single recessive gene, vc-, is responsible for a lowered vicine-convicine concentration. The biosynthetic pathway of these closely related compounds is not known, and the nearest available markers are several cM away from vc-. Improved markers would assist breeding and help to identify candidate genes. A segregating population of 210 F-5 recombinant inbred lines was developed from the cross of Melodie/2 (low vicine-convicine) x ILB 938/2 (normal vicine-convicine), and vicine-convicine concentrations were determined twice on each line. The population was genotyped with a set of 188 SNPs. A strong, single QTL for vicine-convicine concentration was identified on chromosome I, flanked by markers 1.0 cM away on one side and 2.6 cM on the other. The interval defined by these markers in the model species Medicago truncatula includes about 340 genes, but no candidate genes were identified. Further fine mapping should lead to the identification of tightly linked markers as well as narrowing down the search for candidate regulatory or biosynthetic genes which could underlie the vc- locus.