Propagation of two tree ferns (Cyatheaceae) from the Guatemalan cloud forest by three different techniques

Abstract

The tree ferns of the Cyatheaceae family are in danger. They are slow-growing organisms, and their extraction from native forests for use as a substrate substitute for bromeliads and orchids has placed local populations at risk. As organisms with specific requirements for growth and development, an approach to their propagation could serve as the foundation for future conservation projects for these species. Over a period of forty weeks, three different spore propagation methods were compared for the species Cyathea divergens var. tuerckheimii (Maxon) R.M. Tryon and Sphaeropteris horrida (Liebm.) R.M. Tryon; three commercially valuable and easily propagated species were also evaluated as references. A conventional propagation method using prepared peat moss substrate was used as a control, an in vitro treatment using full-strength Murashige & Skoog culture medium (M&S 100) and half-strength nutrient concentration (M&S 50), and an alternative propagation method using an artificial cotton cloth substrate. The goal was to find a cost-effective medium with a germination and establishment rate suitable for future propagation programs of these species. It was found that the in vitro technique achieved a germination rate of 93.15% for S. horrida, while C. divergens achieved only 5.2%. A total of 1,224 young sporophytes of S. horrida were produced, and none of C. divergens. In terms of production costs, the average cost per sporophyte obtained was Q1.10 for substrate cultivation and Q95.96 for laboratory cultivation.