Mitarbeitende

The Early Spider Orchid (Ophrys sphegodes ssp. araneola) is an endangered orchid, indigenous to Switzerland and other European countries. Due to its declining population, it is in great danger of becoming extinct in Europe. The aim of our work is to counteract this decline by strengthening the still existing stock as well as its resettlement with the help of in-vitro germination. Therefore, this work is dedicated to the exploration of symbiotic propagation of O. sphegodes ssp. araneola. Orchid seeds contain very low amounts of nutrient tissue (endosperm). Therefore, they are strongly dependent on a root fungus, which enables the germination and the formation of a protocorm. From a nutrition-physiological point of view, this is one reason why orchids form symbiotic relationships with fungi. Our approach was to examine nine previously isolated mycorrhizal fungi for their potential to facilitate fast and efficient germination of orchid seeds. Three asymbiotic culture mediums, previously used for in-vitro reproduction of orchids, served as a reference. The course of germination was followed by microscopic examinations. Successful germination of the orchid seeds was observed for four out of the nine fungi tested. Two of the examined fungi digested the orchid seeds, for the others no initiation of germination was ob-served until the end of the experiment after 76 days. Our results show a positive effect of the fungi Mfi Hihi St. B. and Mfi Ceru1 KSSG on the germination of orchid seeds in-vitro. These mycorrhizal fungi are promising candidates for future in-vitro reproduction experiments.