Cytogenetical evidences for hybrid structure and origin of diploid and triploid shallots (Allium cepa var.viviparum,Liliaceae) from Dalmatia (Croatia)

Two viviparous strains of common onion (Allium cepa) denoted asAllium cepa var.viviparum (syn.Allium ×proliferum), traditionally cultivated in the seaside regions of Croatia were found to be diploid (2n = 2x = 16) and triploid (2n = 3x = 24), respectively. The triploid cultivated onion Ljutika has not been previously reported in Europe. Using Feulgen and Giemsa C-banding methods both karyotypes were shown to be of hybrid constitution. Results obtained in this work indicate that Dalmatian viviparous onions arose from spontaneous hybridization ofA. cepa withA. fistulosum.