B1.3 Mycorrhizal fungi for growth and rehabilitation of orchids of a tropical mountain rain forest in southern Ecuador
PI(s) for this project:Dr. rer. nat. habil Ingrid Kottke
Orchids are the most species rich group of vascular plants in the megadiverse tropical mountain forest of southern Ecuador and also of high economic value. At same time, orchids are extremely endangered because of fast loss of habitats, and strategies for rehabilitation should be developed. Germination of orchids, and thus their occurrence, depends on symbiotic fungi. In the investigation area, only the mycobionts of four epiphytic orchids are so far known from previous studies by the applicant. The fungi belong to Tulasnellales and Sebacinales, but are distinct from species of other countries. In order to understand natural recruitment potential in the tropical mountain area and to raise orchids more successfully in the greenhouse, vertical and horizontal transfer potential of the mycorrhizal fungi among orchid species and habitats has to be known. A comprehensive inventory shall be carried out on the mycobionts of terrestrial, humus inhabiting, and stem epiphytic orchids on regenerating landslides and man managed forest sites, the forest borders, and inside the pristine forest. Fungi shall be identified by molecular sequencing, isolation, and sexual stages. Fungal support of micro-propagated orchids shall be tested. Other main ecological constraints for orchids like climate, pollinators, and pathogens shall be considered in cooperation with members of the research unit.
In the current project we search for dominant mycobionts of unrelated terrestrial and epiphytic orchids to clarify narrow or broad associations, the fungal community structures and relationships with climate conditions in different habitats across multiple spatial scales. A climate model currently developed by the group around Jörg Bendix will provide monthly insolation, rainfall and temperature at 10 m2 resolution inside the forest as well as on open areas. We installed 56 plots on four sites and roots of 4 to 5 terrestrial, humus-epiphytic and stem-epiphytic orchids were sampled per plot. The DNA was extracted. First results from mycobiont sequences of two orchid individuals per plot indicate a dominance of Tulasnellales in epiphytic and terrestrial/humus-epiphytic orchids, and Sebacinales to be less frequent.