Abstract Detail

Species delimitation in polyploid complexes

Oberprieler, Christoph [1], Lautenschlager, Ulrich [2], Wagner, Florian [2], Ott, Tankred [2], Scheunert, Agnes [2], Vogt, Robert [3].

Species delimitation in the polyploid complex of the genus Leucanthemum Mill. (ox-eye daysies; Compositae-Anthemideae).

Coalescent-based delimitation of evolutionary significant units is established quite well as a useful tool in species circumscription in plants on the diploid level using sequence data. Software programs like the BEAST-based implementations DISSECT [Jones et al., Bioinformatics 31: 991-998] and STACEY [Jones, J. Math. Biol. 74: 447] or the stand-alone application BPP [Yang & Rannala, Mol. Biol. Evol. 31: 3125-3135] are presently used for species delimitation in diploid plant and animal groups. However, due to the paramount role of polyploid species formation in flowering plants more sophisticated bioinformatic tools are needed to disentangle evolutionary significant units (species) on the polyploid level. With gene flow at the diploid and polyploid level, multiple formation of polyploid species, often under reciprocal parentage, and the young age of polyploid species species delimitation in polyploid complexes constitute the ultimate challenge for a DNA-based, phylogenetic species delimitation approach. The present contribution summarizes the state-of-the-art of our project aiming at the establishment of a methodological pipeline for species delimitation in the polyploid complex of the genus Leucanthemum Mill. (ox-eye daysies; Compositae-Anthemideae). Our present data set comprises sequence information for nine nuclear single-copy markers and intergenic spacer regions of the chloroplast genome for all diploid species of the genus and four tetraploid representatives from S France (i.e., L. delarbrei, L. ircutianum, L. meridionale, L. monspeliense). Species delimitation on the diploid level carried out with DISSECT/STACEY reveals clear limits among lineages of an ancient stock of Leucanthemum taxa, while delimitation of species in the more recently evolved L. vulgare-group remains problematic. For the delimitation of evolutionary lineages on the tetraploid level, alleles of tetraploid accessions were assigned to parental genomes (´pseudo-diploids´) with a novel parsimony-based permutation approach and the parentage of tetraploid species inferred by parsimony network reconstruction. Our reconstructions point towards the origins of all four tetraploid taxa from within the L. vulgare-group, but with different parentages of the four tetraploid lineages. These sequence-based results will be complemented with species-delimitation analyses based on Genotyping-by-Sequencing (GBS), morphological and eco-climatological data.

1 - Institute Of Plant Sciences, University Of Regensburg, Universitaetsstr. 31, Regensburg, Bavaria, D-93040, Germany
2 - University of Regensburg, Institute of Plant Sciences, Universitaetsstr. 31, Regensburg, Bavaria, D-93040, Germany
3 - Freie Universitaet Berlin, Botanic Garden & Botanical Museum Berlin-Dahlem, K├Ânigin-Luise-Str. 6-8, Berlin, Berlin, D-14191, Germany

species delimitation
coalescent theory.

Presentation Type: Colloquium Presentations
Abstract ID:478
Candidate for Awards:None

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