Genomics of Yellow Lupin (Lupinus luteus L.)

Yellow lupin (Lupinus luteus L.) is a minor annual legume crop valued for its productivity in highly infertile, acidic soils and for its very high protein seeds. Yellow lupin belongs to the ‘Old World’ group of lupin species and is closely related to narrow-leafed lupin. Yellow lupin shares similar climatic adaptation to narrow-leafed lupin over which it offers some additional advantages such as greater water-logging tolerance and disease resistance. Despite its promise, yellow lupin is grown only as a niche crop in Australia, Europe and South America, and has attracted very limited breeding attention to date. Major constraints to the wider uptake of yellow lupin as a crop include lack of diversity in the domesticated gene pool and a historic focus on adaptation to a limited range of environments. Current varieties are also sensitive to some abiotic stresses (notably drought, extreme temperatures, salinity and alkalinity) and to sap-sucking insects such as aphids. Good genetic resources are available for yellow lupin including extensive seed collections that capture much of the species-wide diversity and three recombinant inbred line populations. Until recently, yellow lupin has lagged behind its well-resourced sister species narrow-leafed lupin in terms of genomic resources but is now catching up. Transcriptomic datasets have been used to generate molecular markers and to investigate the causes of flower and pod abortion. The first genetic map for yellow lupin was recently released, which is being used to investigate phenology, domestication traits and productivity under water-limiting conditions. Transgenesis methods have been developed for yellow lupin, a key enabling technology for future genome editing activities. Efforts are underway to develop a high-quality reference genome sequence for yellow lupin. These developing resources will help researchers acquire knowledge and molecular tools to equip lupin breeders to overcome the restraints on broader adoption of this promising legume crop.