A comparative study of the seed germination capabilities of Anacamptis palustris (Orchidaceae), a threatened terrestrial orchid, and other more common Anacamptis species, by asymbiotic culture in vitro

The increasing emphasis on terrestrial orchid conservation has led to conservation actions for a wide range of threatened Mediterranean species. Many terrestrial orchids are currently at great risk for extinction as a result of a multiplicity of threatening processes. We focus on orchid seed germination capabilities in vitro, specifically germination capability of a threatened species, Anacamptis palustris, compared to three other more common species (A. laxiflora, A. morio, and A. papilionacea), and also discuss its potential impact on orchid distribution and conservation. Asymbiotic germination tests were performed with mature seeds using BM-1 medium. In vitro seed germination and protocorm developmental stages were evaluated up to 20 weeks after sowing. Significant differences in seedling development were detected among the species, and a correlation was evident between the rarity of the species and their germinability. Thus, the presence of intrinsic, biological factors that affect and limit the distribution of A. palustris may exist.