Abstract Detail

Polyploidy, microevolution and species level systematics

Marhold, Karol [1], Spaniel, Stanislav [2], Zozomová-Lihová, Judita [1].

Assessment of evolutionary relationships and taxonomy in the Alyssum montanum-A. repens complex (Brassicaceae) in Central and Southern Europe and Morocco.

The Alyssum montanum-A. repens complex is a group of perennial herbs growing on calcareous or serpentine rocks, sands and in dry grasslands. They occur in most of Europe and adjacent areas with the centre of diversity in the southern part of their distribution range. Their wide geographic distribution coincides with a considerable morphological and ploidy level variation. Several species and numerous infraspecific taxa were traditionally recognized within the group. The primary focus of our studies was to unravel evolutionary history of this complex in the context of Mediterranean refugia and to propose sound taxonomic concept for its classification. Recently, we reassessed the infraspecific classification of A. montanum in C Europe and revealed different evolutionary histories of two subspecies: recent spread of widely distributed diploid-tetraploid subsp. gmelinii, an increased diversity within populations of geographically restricted diploid subsp. montanum, and an allohexaploid origin of stenoendemic subsp. pluscanescens. We confirmed that A. repens is a separate species, which comprises slightly morphologically differentiated diploids and tetraploids. In addition, A. repens was shown as one of the supposed progenitors of the allopolyploid A. montanum subsp. pluscanescens. We also recognized an Apennine species A. diffusum with three subspecies occupying distinct geographic regions: diploid subsp. garganicum, tetraploid subsp. calabricum and diploid to hexaploid subsp. diffusum. In our ongoing studies we focus on the populations from Balkan and Iberian Peninsulas and from Morocco, employing flow cytometry, multivariate morphometry, AFLP analyses, and cpDNA sequences. A number of local endemics from the Balkan Peninsula as A. wierzbickii, A. reiseri, A. moellendorfianum, and A. stribrnyi are confirmed to be distinct by both AFLP and cpDNA data. On the other hand, the relationships among clades are poorly resolved and there are numerous indications of chloroplast capture resulting from past hybridisations. Populations from the western Balkans (NE Italy, S Slovenia, Croatia, W Bosnia and Herzegovina) emerged as a clearly differentiated lineage composed of two genetically and geographically separated diploids with genetically admixed tetraploids (presumably allopolyploids). We provide also an insight into the cytogeography and phylogenetic relationships of populations of A. atlanticum, A. cuneifolium, A. gadorense, A. loiseleurii, A. montanum and A. nevadense occurring in France, Spain and Morocco.

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1 - Institute of Botany, Slovak Academy of Sciences, Dúbravská cersta 9, Bratislava, SK-84523, Slovak Republic
2 - Charles University in Prague, Department of Botany, Benátská 2, Praha 2, CZ-12801, Czech Republic

Keywords:
Cruciferae
Alyssum
Polyploidy
speciation
AFLP
cpDNA
multivariate morphometrics.

Presentation Type: Symposium or Colloquium Presentation
Session: C9
Location: Belle-Chasse/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 3:00 PM
Number: C9004
Abstract ID:562
Candidate for Awards:None