Development of Rapid Propagation Systems for Hemerocallis sp. (Daylilies)

Abstract

Daylilies (Hemerocallis spp.) are ornamental flowering plants with over 80,000 unique registered cultivars. Traditionally propagated through division, multiplication rates range from 1-20 divisions per season depending on cultivar, leading to a delay of up to 17 years for newly registered cultivars to reach a marketable level of plant material. Micropropagation offers an alternative approach that can dramatically increase multiplication rates and is used extensively for the species. However, protocols have only been developed for a selected number of genotypes and many protocols go through a callus phase introducing concern over somaclonal variation. The objective of this study was to evaluate the multiplication stage of micropropagation to optimize a protocol that minimizes unwanted callus with some degree of compatibility among different cultivars. With the use of multiple cytokinins in a liquid medium, a protocol has been established and successfully used to bring several cultivars into culture.