The use of a new culture medium and organic supplement to improve in vitro early stage development of five orchid species

Abstract

Due to the high demand, orchid propagation by in vitro techniques has lately increased, with an emphasis on the ways to improve germination and seedling development. In this work we compare the efficiency of three classic media for orchid propagation with a newly formulated medium supplemented with almond milk. Our target species responded differently to both the media and the supplement. However, with the exception of Bulbophyllum plumatum that did not show statistical differences with the most common media, a beneficial effect on orchid development growing on the new supplemented medium was observed for Cymbidium tracyanum, Dendrobium wardianum and for the two European orchid species Dactylorhiza praetermissa and Himantoglossum robertianum, speeding up the development of the latter two species into photosynthetic stages. The new medium could be, therefore, suitable for improving the development of some ornamental orchids and terrestrial orchid seedlings included in conservation projects that need an ex situ approach.

Keywords:

• Ex situ
• germination
• seedling development
• organic supplement
• chlorophyll content

Acknowledgements

This study was performed in the framework of the PhD projects of Jacopo Calevo (PhD School in Biology and Applied Biotechnology, XXXII cycle, University of Turin) and Miriam Bazzicalupo (PhD School in Science and Technology for the Environment and Territory, XXXIII cycle, University of Genoa), both funded by the Italian Ministry of Education and Research (MIUR). Authors are thankful to Mrs. Laura Negretti for SEM pictures, and to Dr. Gabriele Rizzuto and the anonymous reviewers for comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Conceptualization (J.C. and A.C.), investigation (J.C., A.C., I.M., M.B., M.P., N.S.), formal analysis (J.C., A.C.), writing-original draft preparation (J.C.), review & editing (J.C., A.C., I.M., M.B., L.C., A.G.).