DNA barcoding approach fails to discriminate Central European bladderworts (Utricularia, Lentibulariaceae), but provides insights concerning their evolution

Abstract

The main features to distinguish the seven native Utricularia species occurring in central Europe are found in flower shape, but being rarely flowering identification is often doubtful and uncertain. A recent morphometric work highlighted that there are no univocal reliable extra-floral morphological features allowing a safe identification at species level. Therefore, DNA barcoding approach is attempted here. Molecular analyses were performed to search for DNA barcodes using nuclear ITS (rDNA), plastid (cpDNA) trnL-trnF IGS and rps16 intron sequences. Generally, the barcoding approach failed to discriminate Utricularia species, although it could be of some help in the U. minor aggregate. With few exceptions, U. bremii shows peculiar DNA regions different from U. minor for both plastid markers investigated. However, interesting hypotheses could be derived from the obtained networks, including hybridization events to explain the rise of mostly sterile species, such as U. stygia. This species clusters with the other species of the U. intermedia aggregate in plastid phylogenetic graphs, while it is closely related to species of the U. minor aggregate in ITS phylogenetic graphs. Additionally to U. stygia, U. ochroleuca also shows some incongruences in the different markers, at least for some accessions, pointing to the possible occurrence of hybrids.

Keywords:

• Aquatic plants
• carnivorous plants
• evolutionary network
• hybridization
• systematics

Acknowledgements

The authors are deeply grateful to the following people for the permits of collection in protected areas: Jan Steffen and Rolf Hangartner for Zurich area (Switzerland); Jens Peterson for Sachsen-Anhalt area (Germany); Marie-Luise Kiem for Monticolo Lake (Italy) area. They thank Mario Beretta, Lea Bona, David Dolci, Petr Efimov, Angela Peterson and Filippo Tassara for their help during field trips, and Saura Rodrigues Silva, Yoannis Dominguez and Yani Aranguren for their help during lab activity.

Disclosure statement

The authors declare that they have no conflict of interests.

Additional information

Funding

This study was supported (to LA) by the long-term research development project RVO No. 67985939 of the Czech Academy of Sciences.