Format: ORAL

Adriana Arnal1*, Karl-Georg Bernhardt2, Pablo Garca-Murillo3, Riccardo Guarino4, AngeloTroia4, Barbara Turner2, Johanna Weitzel5, Hendrik Schubert5 and Maria A. Rodrigo1

1 Cavanilles Institute for Biodiversity and Evolutionary Biology, C/ Catedràtic José Beltrán 2, 46980-Paterna (Valencia). University of Valencia. Spain, maria.a.rodrigo@uv.es 2 Dep. Integrative Biology and Biodiversity Research, BOKU-University of Natural Resources and Life Sciences, Austria 3 Dep. Plant Biology and Ecology, Faculty of Pharmacy, University of Sevilla, Spain 4 Dep. Biological, Chemical and Pharmaceutical Sciences and Technologies, Univ. Palermo, Italy 5 Institute for Biosciences, Chair Aquatic Ecology, University of Rostock, Germany

Chara canescens is a charophyte algae, which plays an important role in the ecosystems that it inhabits. This species is unique within its genus because it presents two different reproductive strategies: parthenogenesis, which is unusual in this genus, and sexual reproduction. Parthenogenetically reproducing populations are known for coastal brackish lagoons world-wide, so they are not considered as rare; however, sexually reproducing populations are restricted to Mediterranean and Pannonian inland brackish water sites, with only a few populations recorded in the last decades. The genetic flow of both populations types through stepping-stone habitats is key to the genetic diversity of the species; and its conservation. The parthenogenetically reproducing populations lack at least some of the genetic recombination mechanisms and consequently are more vulnerable to loss of genetic diversity compared to sexually reproducing species. This fact means that protection measures limited to the coastal stands will not be effective, because the fitness of these stands depends to a high degree on connectivity with inland brackish water sites. With the aim of developing effective transnational conservation strategies, the project “ProPartS” (Biodiversa+) assesses the restoration potential of the species’ diaspore bank. The oospores are the charophytes sexual propagules, which can remain viable in the sediment during years and develop new individuals when the conditions are suitable again. Analyzing these oospores (in terms of vitality, germination rate, interfertility assessment…) and assessing the possible differences between the sexually or parthenogenetically produced ones may help to develop effective conservation actions and restoration initiatives for the species. These “hidden biodiversity elements” act as reservoirs and can ensure mid-term resilience of temporary and/or degraded habitats and be potentially useful for the restoration of lost habitats. This is especially important in the context of a changing environment dealing with increased droughts and other threats for the aquatic ecosystems.