Further studies with interspecific hybridization among mediterranean/African lupin species

Summary

Interspecific hybridization has a role to play in the domestication of wild species through the introgression of desirable genes from related domesticated species. Almost complete genetic isolation among the Mediterranean-African rough-seeded lupin species has hitherto ruled out introgression within that group. Recent work in Western Australia with L. atlanticus, L. cosentinii, L. pilosus and L. digitatus has nevertheless suggested that hybrid sterility may be overcome if specially selected lines of each are used in crossing. We have now selected F₂-F₅ plants and backcrosses (Bc₁; Bc₂) from L. atlanticus/L. cosentinii, some with improvement in seed fertility combined with domestication genes from either species. Relatively better F₁-F₂ plant fertility in subsequent crosses of L. atlanticus/L. digitatus than in L. atlanticus/L. cosentinii or L. digitatus/L. cosentinii indicate closer relationship between L. atlanticus and L. digitatus than in the other cross combinations. Use of embryo culture may help to overcome L. pilosus/L. atlanticus F₁ plant sterility. Some of the interspecific selections could act as genetic bridges between L. cosentinii and L. pilosus.