Bulb-type onion introgressants posessing Allium fistulosum L. genes recovered from interspecific hybrid backcrosses between A. cepa L. and A. fistulosum L.

Abstract 

Allium fistulosum possesses a number of traits which would be desirable in A. cepa. Thus far, no commercial A. cepa cultivars have been released which harbor Allium fistulosum traits. F₁BC₃ populations were generated for this study by backcrossing A. cepa to A. cepa×A. fistulosum hybrids. The F₁BC₃ plants were evaluated for plant morphology, floral characters, male- sterile cytoplasm, soluble solids and pungency, and isozymes. Overall growth habit and floral characters of the F₁BC₃ plants were much like A. cepa. We report here the recovery of recombinant, bulbing, and fertile A. cepa-type onions that exhibit A. fistulosum isozyme alleles and morphological markers. Recombination between A. cepa and A. fistulosum genomes was achieved using the introgression strategy of backcrossing A. fistulosum into A. cepa, thereby ameliorating the nuclear cytoplasmic barriers that occurred in previous less successful introgression attempts when plants were not in A. cepa cytoplasm. We believe this report to be the first demonstration of onion introgressants that are like A. cepa in appearance, are male- and female-fertile, and possess A. fistulosum genes.