Abstract
An effective method for producing doubled haploid plants of the Asiatic hybrid lily 'Connecticut King' was established with an in vitro colchicine treatment of haploid calli. With an increase in the concentration and duration of colchicine treatment for the haploid calli, both the survival rate and the shoot regeneration from the calli decreased, but the frequency of diploid cells in the callus increased. Treatments of 0.25 and 0.5 mM colchicine for 48 or 72 hrs induced doubled haploid cells and shoot differentiation from calli. Haploid and diploid plantlets were regenerated from colchicine-treated calli, and only haploid plantlets were formed in colchicine-free treatments. This result suggests that these diploid plantlets originated from doubled haploid cells. Double haploids developed bulblets with more scaly leaves with longer stomatal guard cells than did the haploid plantlets.
