Plant regeneration through various explants of Lilium longiflorum hybrid "Bright Tower" and determination of ploidy level of regenerated plants

The research was conducted to investigate the capacity for shoot regeneration of leaf (apical, middle, and basal parts) and stem (internodal and nodal segments) of Lilium longiflorum hybrid "Bright Tower". When the explants were examined on the Murashige and Skoog medium containing different concentrations of naphthaleneacetic acid and 6-benzyladenine combinations, only nodal explant induced shoots on plant growth regulator (PGR)-free medium, while the other explant sources induced shoots on the media containing PGRs. However, no shoot formation was observed in the apical parts of leaves. Of the different explants used, in general, nodal segments exhibited the highest frequencies of shoot formation and mean number of shoots per explant followed by middle parts of leaves, internodal segments, and basal parts of leaves regardless of PGRs. Ploidy analysis of regenerated plants using flow cytometer also revealed the same ploidy level (diploid). This study will be useful for Agrobacterium-mediated transformation and for large-scale multiplication of this cultivar.