Application of tissue culture for Laburnum anagyroides medik. Propagation

Abstract

Laburnum anagyroides, a small tree or shrub from the Fabaceae family, is a promising object for its use in decorative landscaping and as a source of pharmaceuticals. The conventional propagation methods are not always successful for L. anagyroides. Herein, we describe an approach involving the application of tissue culture techniques for its micropropagation. This approach is based on activation of the pre-existing meristems from the axillary buds taken from a mature tree or seedling explants and includes the following phases: (1) preparation of primary explants and their cultivation on the Murashige and Skoog (MS) medium supplemented with 2.22 µM 6-benzylaminopurine (BAP), hot water pretreatment with subsequent cultivation of the seeds on a MS medium used to overcome the physical dormancy of seeds, (2) proliferation of the initiated explants on the full-strength (for seedling explants) or 1/2 MS medium (for axillary buds) with 2.22 µM BAP, (3) rooting of individual shoots on the 1/4 MS medium supplemented with 2.68 µM α-naphthaleneacetic acid, and (4) acclimatization of the plants by spraying with the Emistim® elicitor. It was found that the explanting season also affected the initiation frequency from axillary buds but did not influence the culture initiation from seedling explants. In the tissue culture of both buds and seedlings, BAP not only stimulated higher number of shoots but also ensured the development of normal shoots compared with the thidiazuron-containing medium. The results of our study can be used for the mass propagation of L. anagyroides and for obtaining good-quality seedlings suitable for gardening and for pharmaceutical industry.