IN VITRO TETRAPLOID INDUCTION IN TULIP (TULIPA GESNERIANA L.)
Polyploids, especially triploids and tetraploids are widely used in the breeding programs of ornamental plant species, due to their desirable traits such as vigorous growth, large leaves or flowers. Tetraploids per se can constitute the new cultivars but, first of all, they can be utilized for further breeding. The cultivar Fringed Black and three diploid breeding clones (Pol-D 21, Pol-D 32 and Pol-D 50) of tulip were used for in vitro polyploidization. The initial explants (flower stem fragments), isolated from the cooled bulbs, were treated with antimitotic agents, oryzalin and amiprophos methyl, by the incubation of explants for seven or fourteen days on the regeneration medium containing above mentioned chemicals at the concentration of 5 and 10 mg L-1. Subsequently explants were transferred on the same medium without antimitotic agents and subcultured three times every four, six and eight weeks, respectively. Then, bulb formation was induced by cooling of the regenerated shoots for 14 weeks at 5°C. The obtained bulbs were rooted ex vitro. Ploidy evaluation, using flow cytometry (performed just before cooling), revealed that tetraploids were obtained for the two genotypes, four tetrapoids (28.6%) in genotype Pol-D 21 and sixteen ones (33.3%) in genotype Fringed Black. Both oryzalin and amiprophos methyl induced tetraploid production.
Podwyszyńska, M. (2012). IN VITRO TETRAPLOID INDUCTION IN TULIP (TULIPA GESNERIANA L.). Acta Hortic. 961, 391-396
Tulipa gesneriana, oryzalin, amiprophos methyl, polyploidization, micropropagation, flow cytometry