plants Article Comparative Germination Ecology of Two Endemic Rhaponticum Species (Asteraceae) in Different Climatic Zones of the Ligurian and Maritime Alps (Piedmont, Italy) Valentina Carasso 1,* , Marco Mucciarelli 2, Francesco Dovana 2 and Jonas V Müller 3 1 Centro Regionale Biodiversità Vegetale, Ente di gestione delle Aree Protette delle Alpi Marittime, Via S. Anna, 34, 12013 Chiusa di Pesio, Italy 2 Department of Life Sciences and Systems Biology, Viale P.A. Mattioli, 25, Università di Torino, 10125 Torino, Italy;
[email protected] (M.M.);
[email protected] (F.D.) 3 Royal Botanic Gardens Kew, Millennium Seed Bank, Conservation Science, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK;
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[email protected]; Tel.: +39-171-734021 Received: 17 April 2020; Accepted: 30 May 2020; Published: 2 June 2020 Abstract: Comparative studies of seed germination of closely related taxa can help increase our understanding of the ecological limitations of cold-adapted plants and forecast how they might respond to global warming. No studies exist on the relationship between thermoclimatic belts that classify mountain life zones according to bioclimatic criteria and the germination strategy of alpine plants. The aim of this study was to assess this relationship using two closely related species growing in different thermotypes and to test whether their germination responses were related to the climate at natural sites. Fresh Rhaponticum bicknellii and R. scariosum seeds were cold stratified for 0, 30, 60 and 90 days and tested for germination at 10, 15 and 20 ◦C. At the same time, seed burial experiments were run in the field and in the plant nursery.