The current state of steppe perennial plants populations: a case study on Iris pumila

Ivan Yu Parnikoza , Igor Andreev , Olena Bublyk , Kateryna Spiridonova , Joanna Gołębiewska , Magdalena Kubiak , Anna Kuczyńska , Katarzyna Mystkowska , Natalia Olędrzyńska , Barbara Urasińska , Anna Ślęzak-Parnikoza , Marcin Górniak , Krzysztof Wojciechowski , Yakiv Didukh , Viktor Kunakh

Abstract

A comprehensive study of a typical steppe perennial Iris pumila L. were carried out in the central zone of the European part of this species’ range, namely in Ukraine. Intraspecific differentiation, population size and isolation degree and its consequences, the threat of human impact were analyzed, as well as ecological amplitude and genetic variation in ISSR markers and selected chloroplast regions were determined. The species was found to have a low intraspecific differentiation that indicates the uniformity of the gene pool in the studied part of the range. Moreover, the results of isolation assessment, population and ecological study of I. pumila confirm the potential risk of extinction. A considerable part of the species populations exist as separated patches of rare ecosystems, isolated from the nearest neighbours due to intense plowing of the steppe zone. The generative reproduction is rare. In contrast, ISSR analysis revealed comparably high genetic diversity in all the sampled populations. Furthermore, specific plastid haplotypes were demonstrated in some of them. The inconsistency between the results of population ecological study and the data of molecular genetic analysis indicates that the loss of genetic diversity in the species caused by habitat fragmentation and isolation under increasing anthropogenic pressure is likely to be slower than it would appear judging from the assessment of population parameters, which clearly show negative trends. This result also emphasizes the necessity for integrated approach to assessment of the extinction risk for particular species and careful analysis of all determinants of extinction.