Gynogenesis in Polish Onion Cultivars

During the two years ofthe studies (1997–1998) 32802 flower buds ofthirty Polish onion genotypes were plated on different media. In total 310 embryos (0.9 %) were obtained, out of which more than a half underwent regeneration. It was established that 3.5–4.5 mm long flower buds were the most responsive to gynogenesis. Out of 6 studied media combinations the highest yield of gynogenic embryos was produced on the B5 or BDS media containing 2.0mg/L 2,4-0 and 2.0mg/L 6BA (denoted as Al and F6 induction media, respectively) followed by the R regeneration medium (BDS supplemented with 1.0 mg/L NAA and 2.0 mg/L 2iP). It was observed that the cultivars differed with regard to their demands for media composition. The yield of embryos strongly depended on the genotype. For 9 genotypes the induction of gynogenesis failed, 12 genotypes yielded 0.2–0.8 % embryos, eight produced 1.0–4.3% embryos while only one gave 10.0% embryos.