Regeneration of haploid plants from anther cultures of the Asiatic hybrid lily ‘Connecticut King’

A system for producing haploid plants from anther cultures was developed for the Asiatic hybrid lily ‘Connecticut King’. Anthers containing microspores at the mid- to late-uninucleate stages were cultured on MS media supplemented with various plant growth regulators. Microspores containing 3 or 4 vegetative-like nuclei were observed 2 to 3 weeks later, and yellowish nodular calluses appeared within dehisced anthers 2 to 3 months after culture. Picloram was superior to 2,4-d for inducing nodular calluses. Anthers from greenhouse-grown plants required higher concentrations of both picloram and cytokinins than those from field-grown plants and most frequently produced nodular calluses (17.6%) on MS medium containing 2 mg 1⁻¹ picloram and 2 mg 1⁻¹ zeatin. The nodular calluses regenerated many bulblets following transfer to MS medium supplemented with 0.1 or 0.5 mg 1⁻¹ picloram and 0.01 mg 1⁻¹ BA, and the bulblets developed into plantlets (bulblets with scaly leaves and roots) after transfer to MS medium containing 0.1 mg 1⁻¹ NAA. Chromosome counts of root-tip cells of 11 plantlets revealed that five were haploids (2n = 12), two diploids (2n = 24), and four mixoploid. This result suggests that at least some plantlets were of gametophytic origin.