Induction of Multiple Shoots and Roots of Calla Lily ‘Black Star’ through in vitro Propagation

In Korea most bulbs of calla lily (Zantedeschia spp.) are imported from foreign countries including USA and Netherlands due to frequent viral infection problems in field propagation. To solve this problem, in vitro propagation system of calla lilies has been attempted, which ultimately would have an agronomical impact on Korean calla lily farmers. In this study, we carried out experiments to find an efficient method for multiple shoot formation and subsequent root induction in calla lily ‘Black Star’. Lateral buds were used for the induction of multiple shoots on basal MS media containing various concentrations of auxin and cytokinin. The highest callus and multiple shoot formation was observed in MS medium containing 1.0 mg/L of each NAA and BA, in which 25 (83.3%) explants exhibited callus formation and all 30 explants produced multiple shoots with an average of 14.7 shoots per explant in average length of 4.1 cm. Subsequently, obtained shoots were tested for root induction in MS media containing auxins, IAA, NAA, or 2,4-D, because calla lily shoots derived from tissue culture did not produce sufficient roots that are crucial for the survival under natural environment after transplanting. An average of 4.9 or 3.1 roots was generated after 20-day culture of shoots on MS media containing 1.0 mg/L IAA or 1.0 mg/L 2,4-D, respectively. However, no root formation was observed in MS media supplemented with NAA, indicating that NAA is not adequate for root induction of shoots derived from tissue culture of ‘Black Star’.