Elimination of chrysanthemum stunt viroid from an infected chrysanthemum cultivar by shoot regeneration from a leaf primordium-free shoot apical meristem dome attached to a root tip.

In this research we eliminated chrysanthemum stunt viroid (CSVd) from a highly infected chrysanthemum cultivar using a newly established method. 'Piato' is one of the most difficult cultivars in which to obtain CSVd-free plants by conventional methods. Leaf primordium-free shoot apical meristems (LP-free SAMs) of 'Piato' plants were dissected and attached to CSVd-free chrysanthemum or cabbage root tips. As shown by nested-PCR, CSVd was not detected in some shoots regenerated on both types of root tip. The production rates of CSVd-free plants using chrysanthemum and cabbage root tips were 14% and 3%, respectively. Regeneration of plants from LP-free SAMs of chrysanthemum plants by attaching these SAMs to root tips is an efficient method of generating CSVd-free chrysanthemum plants.