Factors affecting Zantedeschia Spreng. dedifferentiation in vitro

Zantedeschia Spreng. is an economically important ornamental plant species. Improvement of aesthetic parameters and creation of novel variations of decorative plants are important economic goals for the commercial ornamental industry. The effect of the combination of growth regulators and the explant type on dedifferentiation induction in Zantedeschia aethiopica and Zantedeschia elliottianna was investigated. Research was carried out at the Institute of Biology and Plant Biotechnology of Aleksandras Stulginskis University and at the Laboratory of Agrobiotechnology of the Joint Research Centre in 2016–2017. Explants (leaf discs, spathe discs, and petiole segments) were cultured on the MS medium supplemented with different concentrations of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) and 6-benzylaminopurine (BAP), 30.0 g l–1 sucrose, and 8.0 g l–1 agar. Leaf discs and spathe discs did not show any response in the medium without growth regulators, while 16.3% (Zantedeschia aethiopica) and 24.3% (Zantedeschia elliottianna) of isolated petiole segments formed callus. Our results showed that an appropriate combination of growth regulators for callus induction varied depending on the genetic background and the explant type. It was documented that isolated petiole segments of the arum lily and the calla lily induced more statistically reliable callus in a medium supplemented with combination BAP + IAA, while the combination BAP + IBA promoted callus formation from spathe disc tissues. Petiole segments manifested the highest dedifferentiation capability among the tested explant types. The results of the study showed that the ability of the somatic tissues of the arum lily and the calla lily to induce dedifferentiation seems to be a valuable material for improvement of ornamental values in these plants.