A multiplex PCR marker distinguishes between a series of four LanFTc1 alleles regulating flowering time in narrow-leafed lupin (Lupinus angustifolius)

We designed and validated a new multiplex PCR marker which discriminates between four insertion/deletion (INDEL) alleles in the 5 ' regulatory region of a major flowering time gene in Lupinus angustifolius, LanFTc1. The four INDEL alleles were the wild-type allele (ku) in variety 'Geebung' (G), a 1,208-bp deletion allele in accession P22660 (P), a 1,423-bp deletion allele (Ku) in variety 'Tanjil' (T) and a 5,162-bp deletion allele (Jul) in variety 'Krasnolistny' (K). F-2 PCR marker genotypes segregated as expected in populations K x G, K x T, P x G and P x T. Heritability of flowering times based on F-2:3 parent:offspring correlation was high in K x G (0.81 +/- 0.09), P x G (0.76 +/- 0.10) and P x T (0.81 +/- 0.11) but low in K x T (-0.04 +/- 0.15) due to similar early-flowering phenotypes produced by Ku and Jul. Progeny homozygous for the 1,208-bp deletion allele resulted in a unique array of mid-season phenology in the F-2, F-3 and F-4 generations, which may improve agronomic adaptation. This multiplex PCR marker will improve the efficiency of introgression of the new INDELs into future lupin varieties.