Mycorrhizal fungi for growth and rehabilitation of orchids of a tropical mountain rain forest in southern Ecuador
Final Report Abstract
The research project is part of the interdisciplinary research unity "Biodiversity and sustainable Management of a mega diverse Mountain Ecosystem in southern Ecuador" and was performed in the tropical mountain rain forest of Reserva Biológica San Francisco (RBSF) in cooperation with the laboratory of Cellular and Molecular Biology of Universidad Técnica Particular de Loja (UTPL), Ecuador. Orchids are the most species rich group of vascular plants in the tropical mountain forest of southern Ecuador where they do not only occur most abundantly as epiphytes and terrestrials in the pristine and regenerating forest, but also cover regenerating landslides, and orchids are of high economic value for Ecuador. At same time, orchids are extremely endangered because of fast loss of habitats and, thus, strategies for rehabilitation have to be developed. Orchids need appropriate, obligate symbiotic fungi for germination and establishment of well performing plantlets through formation of mycorrhizas. It was unclear if the highly diverse Andean orchids occurring in a vast diversity of habitats would need distinct symbiotic fungi adapted to habitats and/or orchid species. Comprehensive sampling of orchid roots was, therefore, carried out in 56 plots on four sites in the RBSF comprising primary forest, regenerating forest and regenerating landslide. Fungal DNA was extracted from the mycorrhizal parts of the roots, amplified by PCR, cloned and sequenced. Transmission electron microscopic studies were additionally carried out to examine the location and interaction of the fungi encountered by molecular techniques in order to discern true mycorrhizal fungi from contaminants. Results so far obtained yielded the well known Tulasnellales as the most important mycorrhizal fungi of epiphytic and terrestrial orchids in all the sites. Sebacinales, also proven orchid mycorrhizal fungi, were much less frequent. Surprisingly, we discovered a new orchid mycorrhizal group of fungi, Atractiellomycetes, previously only known as saprophytes. These fungi occurred in every third orchid individual and in all habitats under investigation. Further research is intended to clarify if these fungi are useful for commercial application to improve orchid seed germination and growth. Basidiomes of Tulasnella were collected in the RBSF, morphologically described and sequenced. The results are used to clarify taxonomic problems and genotype definition in Tulasnellales. Statistical analyses of the data are now under work to clarify species richness and potential adaptation of the fungi to orchid species and environment. Adaptation to climate will be tested by use of models developed by AG Bendix.
Publications
- (2009) Atractiellomycetes belonging to the ‘rust’ lineage (Pucciniomycotina) form mycorrhizae with terrestrial and epiphytic neotropical orchids. Proc. R. Soc. B
Kottke I, Suárez JP, Herrera P, Cruz D, Bauer R, Haug I, Garnica S
(See online at https://doi.org/10.1098/rspb.2009.1884) - (2009) Epiphytic orchids in a mountain rain forest in southern Ecuador harbor groups of mycorrhizaforming Tulasnellales and Sebacinales subgroup B (Basidiomycota). In: Pridgeon AM, Súarez PJ (eds) Proceedings of the Second Conference on Andean Orchids, Universidad Técnica Particular de Loja , pp. 184-196, ISBN 978 9942 00 502 1
Suárez JP, Weiß M, Abele A, Oberwinkler F, Kottke I
- (2009) Mutualistic, root-inhabiting fungi of orchids – identification and functional types. In: AM Pridgeon and JP Suárez (eds) Proceedings of the Second Scientific Conference on Andean Orchids. Universidad Técnica Particular de Loja, Loja, Ecuador, pp 84-99, ISBN 978- 9942-00-502-1
Kottke I, Suárez JP
