Articles
INTERSPECIFIC HYBRIDIZATION IN LILIUM
This is especially due to the development of the Asiatic hybrid lilies, which are derived from only about eight species of the more than 80 species in the genus Lilium.
Widening the genetic basis of the commercial cultivars by the introduction of desired characters (e.g. virus- and Fusarium – resistance from Lilium henryi, low temperature and low light tolerance from L. candidum, yearround forceability and vigorous growth from L. longiflorum) is the objective of an interspecific hybridization program in Lilium.
To overcome crossing barriers, methods involving amputated styles and mentor pollen are used.
The effects of different pollination methods on pollen tube growth were studied by means of UV-microscopy and staining techniques.
Embryoculture was practised to overcome endosperm degeneration and embryo abortion.
Taxonomically, the genus Lilium can be divided into 7 sections.
Crosses between species from four different sections are carried out.
L. longiflorum has been crossed successfully with e.g.
L. candidum, the Asiatic hybrid ‘Mont Blanc’ and L. rubellum.
To restore the fertility of the Fl-hybrids, tetraploid forms are produced by colchicine treatment.
The cross between ‘Shikayama’ x L. henryi, and L. speciosum, ‘Allegra’ and ‘Journey’s End’ resulted in 11 (sterile) triploid hybrids.
Backcrosses with oriental hybrids and L. auratum x L. henryi were successfull in a few cases, even without embryoculture.
Varied interspecific material has been released to commercial breeding firms in the Netherlands.