Establishment of a regeneration system for the production of Calla plants (Zantedeschia spp.) via embryogenic callus culture

Abstract

Calla lilies (Zantedeschia spp.) are monocotyledonous ornamental plants which belongs to the Araceae family. After the release of elite calla cultivar, an efficient propagation system is needed for commercial use. Despite the use of conventional propagation methods such as splitting of tubers and rhizomes of calla, rapid and efficient propagation system should be developed. In order to achieve this goal, stem segments contained apical meristems derived from calla lily cultivar (cv. Gag-si) were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of cytokinin and auxin. This was aimed at inducing embryogenic calluses, shoots and multiple shoots. As a result, about 25% of induction rates of yellow embryogenic calluses were observed with MS medium containing both 0.5 mg･L-1 NAA and 1.5 mg･L-1 BA as growth regulators. In the experiments involving the regeneration from embryogenic calluses through shoot formation, MS medium supplemented with 0.5 mg･L-1 IAA and 2.0 mg･L-1 BA showed the highest rates at approximately 85 ~ 90% with regard to the formation of shoots in calla. Moreover, multiple shoots needed for rapid propagation were generated when explants were cultured on MS medium supplemented with 0.5 mg･L-1 IAA and 2.0 mg･L-1 BA with 40% of formation rate. In this study, the combination of auxin and cytokinin showed positive effects on both the induction of embryogenic calluses, the formation of shoots as well as multiple shoots in calla. The regeneration system described here can contribute to the development of breeding programs of calla in the future.