Ann. Bot. Fennici 45: 186–194 ISSN 0003-3847 (print) ISSN 1797-2442 (online) Helsinki 27 June 2008 © Finnish Zoological and Botanical Publishing Board 2008 Low genetic variation in subpopulations of an endangered clonal plant Iris sibirica in southern Poland Kinga Kostrakiewicz1,* & Ada Wróblewska2 1) Department of Plant Ecology, Institute of Botany, Jagiellonian University, Lubicz 46, PL-31-512 Kraków, Poland (corresponding author’s e-mail:
[email protected]) 2) Institute of Biology, University of Białystok, Świerkowa 20B, PL-15-950 Białystok, Poland Received 2 May 2007, revised version received 5 June 2007, accepted 31 July 2007 Kostrakiewicz, K. & Wróblewska, A. 2008: Low genetic variation in subpopulations of an endan- gered clonal plant Iris sibirica in southern Poland. — Ann. Bot. Fennici 45: 186–194. The spatial genetic structure in three subpopulations of the endangered clonal plant Iris sibirica from southern Poland was investigated. The subpopulations occurred in differ- ent habitats, i.e. in a Molinietum caeruleae community, a Phragmites australis patch and in a willow brushwood. Using 13 enzymatic systems, sixteen loci were evaluated. The very low genetic diversity (P = 0%–18.7%, A = 1.0%–1.19%, HO = 0.000–0.009) observed within the subpopulations is probably due to lack of recruitment, habitat fragmentation and/or historical causes. Five distinct multilocus genotypes, detected from 148 collected samples in the subpopulations, supported this observation. This fact illustrated that only clonal growth could maintain the present low genetic variation through the domination of a single or a few clones within these sites. Moderate genetic differentiation (FST = 0.077, P < 0.001) that varies strongly between pairs of subpopu- lations, was observed, thereby suggesting substantial gene flow between populations.