ARS | Publication request: RFLP AND FISH ANALYSIS OF ADVANCED BACKCROSSES OF AN ALLIUM INTERSPECIFIC HYBRID (ALLIUM CEPA X ALLIUM FISTULOSUM) TO ALLIUM CEPA

Submitted to: Onion Research National Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 25, 2000
Publication Date: N/A

Technical Abstract: Onion (Allium cepa L.) is the most important species of the cultivated Alliums. Breeders have attempted to incorporate quality and resistance traits from Allium fistulosum into the onion genome. Although there are several reports of successful interspecific hybridizations between A. cepa and A. fistulosum, there has not been strong evidence of recombination among the genomes. After more than 50 years of interspecific hybridizatio and backcrossing to onion, no successful introgression has been convincingly documented. The objective of this study was to use FISH and RFLPs to assess recombination between the genomes of A. cepa and A. fistulosum using BC progenies in the normal male-fertile cytoplasm of A. cepa. Sequence divergence between A. cepa and A. fistulosum was sufficient to allow chromosomes to be distinguished by GISH and revealed evidence for recombination among the genomes of A. cepa and A. fistulosum. RFLP analysis demonstrated that advanced backcross populations possess the normal male-fertile cytoplasm and the 45s ribosomal DNA of bulb onion.