Development and validation of PCR marker array for molecular selection towards spring, vernalization-independent and winter, vernalization-responsive ecotypes of white lupin (Lupinus albus L.)

White lupin (Lupinus albus L.) is an ancient grain legume that is still undergoing improvement of domestication traits, including vernalization-responsiveness, providing frost tolerance and preventing winter flowering in autumn-sowing agriculture, and vernalization-independence, conferring drought escape by rapid flowering in spring-sowing. A recent genome-wide association study highlighted several loci significantly associated with the most contrasting phenotypes, including deletions in the promoter of the FLOWERING LOCUS T homolog, LalbFTc1, and some DArT-seq/silicoDArT loci. The present study aimed to develop and validate a versatile PCR marker array enabling molecular selection of spring- and winter-type white lupin ecotypes. Candidate DArT-seq and silicoDArT loci were transformed into cleaved amplified polymorphic sequence (CAPS) or derived CAPS markers. Developed markers, together with those previously published for LalbFTc1 INDELs and quantitative trait loci from linkage maps, were implemented for screening of white lupin germplasm panel subjected to 2-year phenotyping of phenology traits. Three DArT-seq, two silicoDArT and seven LalbFTc1 INDEL markers were positively validated, constituting a convenient PCR-based marker assay for rapid and accurate reselection of white lupin germplasm towards early flowering and thermoneutrality or late flowering and vernalization-responsiveness, as well as for tracking high genetic and phenotypic diversity within white lupin landraces, revealed in the present study.