Transgenic plum (Prunus domestica L.) plants obtained by Agrobacterium-mediated transformation of leaf explants with various selective agents

Plum (P. domestica L.) scion cv. 'Startovaya' was transformed using Agrobacterium tumefaciens strain CBE21:pCamGFP carrying the hygromycin phosphotransferase gene (hpt) and a synthetic codon optimized red-shifted gfp gene; pBin-mGFP5-ER carrying neomycin phosphotransferase gene (nptII) and gfp gene with a leader sequence for expression in endoplasmic reticulum. Whole leaf explants were cocultivated with A. tumefaciens, and selection and regeneration of transformed cells and shoots was carried out during 6-8 months on selection medium containing 35-50 mg/L kanamycin (Km) or 8 mg/L hygromycin. One of 1207 (0% early / 0.23% delayed selection) explants on kanamycin selection and 10 of 793 (0.27% early / 2.2% delayed selection) explants on hygromycin selection cv. 'Startovaya' produced 10/11 GFP and 11/11 PCR-positive independent transgenic lines from the cut midribs via an intermediate callus stage. The selected transformants had a normal phenotype in vitro.