Annals of Botany 119: 81–93, 2017 doi:10.1093/aob/mcw221, available online at www.aob.oxfordjournals.org Do floral and niche shifts favour the establishment and persistence of newly arisen polyploids? A case study in an Alpine primrose Gabriele Casazza1,*, Florian C. Boucher2,3, Luigi Minuto1, Christophe F. Randin4 and Elena Conti2 1DISTAV, University of Genoa, Corso Europa 26, I-16132 Genoa, Italy, 2Department of Systematic and Evolutionary Botany and Botanic Garden, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland, 3Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa and 4Department of Ecology & Evolution, Downloaded from https://academic.oup.com/aob/article-abstract/119/1/81/2730686 by guest on 23 March 2020 University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland *For correspondence. E-mail
[email protected] Received: 18 May 2016 Returned for revision: 29 July 2016 Editorial decision: 10 September 2016 Published electronically: 26 December 2016 Background and Aims Polyploidization plays a key role in plant evolution. Despite the generally accepted ‘mi- nority-cytotype exclusion’ theory, the specific mechanisms leading to successful establishment and persistence of new polyploids remain controversial. The majority of newly formed polyploids do not become established, because they are less common, have fewer potential mates or may not be able to compete successfully with co-occurring progenitors at lower ploidy levels. Changes in floral traits and ecological niches have been proposed as important mechanisms to overcome this initial frequency-dependent disadvantage. The aim of this study was to determine whether dodecaploids of the heterostylous P.