Abstract
Interspecific hybrid of Delphinium, in which sepals were not abscised without silver thiosulphate pre-treatment, was raised. Interspecific cross between D.elatum ‘Magic Fountains White’ and D.grandiflorum ‘Blue Mirror’ was carried out and 18 interspecific hybrid plants were obtained through ovule culture. Seventeen plants were similar to the plant form and flower shape of the belladonna-type, however, one plant (‘M8-16’) was a dwarf-type of ‘Blue Mirror’. The polyploidy of belladonna-like plants and ‘M8-16’ were estimated as triploid and tetraploid, respectively, by flow cytometry. Three plants were obtained by backcrossing ‘Blue Mirror’ to ‘M8-16’. One of them (‘B10’) had very long flowering periods without abscission of sepals. Even sepals of cut florets were not abscised and the vase life of ‘B10’ was significantly longer than ‘Bellamosum’.
