Transgenic lilies via pollen mediated transformation

We have developed a procedure for the production of transgenic lilies by using the pollen grain as vector for DNA delivery. First, a particle gun was used for the introduction of the NPTII gene (for kanamycin resistance) into pollen of lily (Lilium longiflorum), cv ‘Gelria’. Subsequently the bombarded pollen was used for pollination of flowers of cv ‘Indian Summer’. A large number (approx. 400,000) of seeds were harvested, of which 65,000 were tested for in vitro germination in the presence of kanamycin. Three plants that developed well on media with 50μg kanamycin were obtained. These plants were grown-on in the greenhouse. Regeneration of bulbscale explants on kanamycin confirmed the resistance of these selected plants. Furthermore, by using PCR the presence of the transgenes in the genome of the putative transformants was established. To investigate the transfer of the transgenes to the next generation, crosses were made using the three plants as male or female parent. The offspring were tested again for germination on kanamycin-containing medium, and the presence of kanamycin-resistant as well as kanamycin-sensitive seedlings proved that transfer and segregation of the transgenes had occurred. The kanamycin-resistant seedlings of the first generation were positive in the PCR reaction. The results clearly show that transgenic lily plants have been obtained. However, segregation analysis showed that transmission of the genes to the F1 was not mendelian. This will be investigated by following the transfer of transgenes to future generations.