Agrobacterium tumefaciens -mediated transformation and transgenic-plant regeneration of onion ( Allium cepa L.)

• DOI: 10.1007/s002990050743
• Publication Date: 2002-10-06T17:20:48Z
• Authors: C. C. Eady; R. J. Weld; C. E. Lister
• Keywords: 0106 biological sciences; 01 natural sciences

An Agrobacterium tumefaciens-mediated transformation method has been developed for onions (Allium cepa L.) using immature embryos as the explant source. Transgenic plants were recovered from the open-pollinated onion cultivar Canterbury Longkeeper at a maximum transformation frequency from immature embryos of 2.7%. The method takes between 3-5 months from explant to primary regenerant entering the glasshouse. Multiple-shoot formation from primary transgenic material made possible the clonal multiplication of transformants. The binary vector used carried the nptII antibiotic resistance gene and the m-gfp5-ER reporter gene. Transgenic cultures were initially screened for their ability to fluoresce and to grow in the presence of geneticin (5-25 mg/l). The transgenic nature of individual plants was confirmed by Southern blot analysis.