Development of a sequence‐specific PCR marker linked to the Ku gene which removes the vernalization requirement in narrow‐leafed lupin

Wild types of Lupinus angustifolius require vernalization to promote flowering. Modern domesticated cultivars carry the early‐flowering gene Ku which removes this requirement. A microsatellite‐anchored fragment length polymorphism marker was identified as co‐segregating with the Ku gene in a recombinant inbred line (RIL) population derived from a domesticated × wild‐type cross. DNA sequencing showed that the marker contained a 7 bp insertion/deletion polymorphism, as well as a single nucleotide polymorphism. A pair of sequence‐specific primers was designed and successfully converted the size polymorphism into a simple polymerase chain reaction based co‐dominant marker. This marker is closely linked to the Ku gene, as it co‐segregates with the Ku phenotyping in a population consisting of 106 RILs.