A micropropagation method is presented for Ranunculus lyallii Hook. f.
Seedling establishment in culture required surface sterilisation of t
he achene, followed by dissection of the embryo from the other tissues
of the seed. This process was necessary both to avoid the persistent
presence of the fungus Botrytis cinerea and to overcome physiological
dormancy. Seedlings germinated and grew well on an agar-solidified bas
al medium comprising half-strength Murashige and Skoog (MS) salts (Mur
ashige & Skoog 1962), MS organics, and 3% sucrose. Shoot proliferation
increased with increasing 6-benzylaminopurine (BAP) concentration up
to 0.6 mg/litre, whereas higher rates caused shoot distortion and inhi
bited subsequent rooting of plantlets. Shoot proliferation was optimis
ed on basal medium supplemented with 0.2 mg/litre BAP. Root formation
was completely inhibited by BAP, even at 0.1 mg/litre, the lowest conc
entration tested. Adding 0.1-0.5 mg/litre indole-3-butyric acid (IBA)
to the medium had no effect on this response. As shoots readily formed
roots on the basal medium without additional growth regulators, this
formulation was used for rooting in all subsequent manipulations.