Abstract Detail

Phylogenomics

Dorfner, Marco [1], Ott, Tankred [1], Bergmann, Stephan [1], Vogt, Robert [2], Oberprieler, Christoph [1].

Species delimitation in the Leucanthemum atratum-group (Compositae, Anthemideae) based on Genotyping-by-Sequencing data.

The genus Leucanthemum Mill. (Compositae, Anthemideae) is a large polyploid complex comprising 42 species with ploidy levels ranging from diploid (2x) to dodecaploid (12x), and one species [L. lacustre (Brot.) Samp.) from Portugal] even showing a chromosome number of 2n = 22x = 198 (docosaploid level). The genus is distributed all over the European continent, with one species (the tetraploid L. ircutianum DC.) reaching Siberia and some species introduced to many temperate regions of the northern and southern hemisphere. Though no formal infrageneric classification has been proposed due to the scarceness of distinct morphological discontinuities among species groups, at least an informal species assemblage – the L. atratum-group – received acceptance as an independent lineage in some floras. Membership to this group of diploid and hexaploid species was based on the plesiomorphic feature of achenes of tubular florets being furnished with an adaxial corona, while all other species of the genus exhibit apically rounded fruits. We have used Genotyping-by-Sequencing (GBS) of all diploid members of the genus and accessions of the hexaploid L. atratum-group to infer the phylogenetic relationships among the members of the group and to reconstruct the parentage of its hexaploid representatives. The sequencing data was assembled to loci and analysed with the ipyrad pipeline. For dataset comparison purposes, we performed a reference-based assembly using 9,852 loci identified in a previous assembly of all diploid Leucanthemum members. A NeighborNet phylogenetic network based on Nei-Li distances calculated from 324,131 SNPs confirms the L. atratum group as a well-resolved, independent lineage within the genus. The diploid L. halleri was found as a putative parent species of the hexaploids L. atratum, L. coronopifolium subsp. ceratophylloides and subsp. coronopifolium due to their short genetic distance. For the same reasons, the hexaploid L. coronopifolium subsp. tenuifolium originated independently from the diploid L. tridactylites in the central Apennine and should therefore be treated on species level. Additional Sanger sequencing data from four chloroplast markers support our findings from the nuclear GBS analysis.

1 - Institute Of Plant Sciences, University Of Regensburg, Universitatsstr. 31, Regensburg, BY, D-93040, Germany
2 - Botanic Garden & Botanical Museum Berlin-Dahlem, Königin-Luise-Str. 6-8, Berlin, D-14191

Keywords:
polyploidy
Taxonomy
Asteraceae
Europe
Alps
Apennine
GBS.

Presentation Type: Poster
Session: P3, Phylogenomics Posters
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 5:00 PM(EDT)
Number: P3PL006
Abstract ID:380
Candidate for Awards:None