Nikolai Friesen

Aim We hypothesize that molecular signals in Eurasian steppe plants reflect their biogeographical history as well as the climate/landscape history of the Eurasian steppe. To test this hypothesis we focus here on the characteristic Eurasian steppe genera Dontostemon and Clausia (Brassicaceae), and have included all presently accepted species in our study. Location Eurasian steppe from eastern Asia to southeastern Europe. Methods To elucidate their phylogeny, we sequenced the nuclear ribosomal ITS and chloroplast trnL-F regions. Sequence data were analysed with parsi-mony and Bayesian phylogenetic approaches. Divergence times were estimated using BEAST, relying on published ITS substitution rates. Distribution maps of all species of the two genera were compiled, and ancestral areas reconstructed using LAGRANGE. Results Both genera originated in central and eastern Asia, with Clausia later extending its range to eastern Europe. Dated phylogenies revealed: onset of diversification in the lower and middle Miocene; evolution of the majority of groups in the upper Miocene/lower Pliocene, and further speciation events during the Quaternary. Origin and diversification within these genera coincide with the evolution and history of the modern Eurasian steppe. Main conclusions Dated phylogenies and historical biogeography of Clausia and Dontostemon mirror the climate/landscape dynamics of the steppe from its origin in the early Miocene up to the Pleistocene and Holocene.

In the living Allium collection of the South Siberian Botanical garden of the altai State University, Barnaul (russia), among the species Allium tulipifolium and A. robustum (A. subg. Melanocrommyum sect. Decipientia), several morphologically intermediate plants grown from seeds were found. We assumed they could result from spontaneous hybridization. to confirm our assumption we studied the hybrids and their alleged parents cytologically (chromosome and genome size) and compared the sequences of the nuclear dNa (ItS) and three plastid dNa fragments (trnl-trnF and rpl32-trnl spacers and rps16 in-tron). our data confirmed the hybrid nature of these plants and also showed that the hybridization between the two species (A. tulipifolium and A. robustum) is possible in both directions. this opens up opportunities for targeted hybridization and breeding of new ornamental varieties.

Allium section Rhizirideum constitutes a group of approximately 24 species, distributed mostly in steppe areas of the Eurasian temperate zone. Its phylogenetic relationships are therefore relevant for understanding of the evolutionary and biogeographical patterns of the Eurasian steppes. Based upon DNA sequences from two plastid regions (trnQ-rps16 and trnL-rpl32) and the internal transcribed spacer region of nuclear ribosomal DNA, the phylogenetic relationships in Allium section Rhizirideum are investigated by using maximum parsimony and Baye-sian inference. Dated phylogenies revealed (1) that diversification started in the upper Pliocene and further speciation events occurred during the Pleistocene and (2) a clear division of the section Rhizirideum into an ''Asiatic'' and ''European'' geographical group. Nomenclature, distribution maps and identification key for all species are provided. Origin and diversification within this section thus reflect the development and history of the modern Eurasian steppe. Keywords Allium Á Dated phylogeny Á ITS Á Polyploidy Á Rhizirideum Á Taxonomy Á trnL-rpl32 Á trnQ-rps16

The disjunct distribution of the subgenus Anguinum of the genus Allium makes it a good candidate to test models of Northern hemisphere biogeography. Here we conduct phylogenetic analysis with the nuclear marker ITS and three different chloroplast markers (rps16 intron, rbcL-atpB spacer, rpl32-trnL spacer). Divergence time estimations (Beast) relying on published ITS substitution rates and ancestral range reconstructions were calculated to elucidate the biogeographical history of the subgenus. Additionally we compiled distribution maps for all species with data taken from the literature, herbariums and data from field observations. The main radiation of the subgenus took place in the last one million years and is still going on. They have their origins in the mid Miocene in East Asia and were highly influenced by the climate fluctuations in the Pliocene/Pleistocene period. Conflicting tree topologies between nuclear and cpDNA markers of Allium tricoccum Solander indicate that the species is of hybridogenous origin. Cloning the ITS sequence revealed the parental copies and confirmed our conclusion. One originated from the Eurasian and the other from the East Asian clade. We were able to show that it reached North America most likely via the Beringia around 2.5 mya (95% HPD of 0.35 - 5.26 mya). Our data suggest that Allium victorialis L. is only distributed in mountain pastures in Europe as it forms a well-supported clade in the ITS tree. In the analysis of the molecular markers we found two distinct types of Allium ochotense Prokh. and we suggest splitting the species based on Prokhanov́s (1930) proposal. Taxonomical remarks and an identification key to all species of the subgenus Anguinum is provided.

Sequence data from the nuclear ribosomal internal transcribed spacer (ITS) region for 189 accessions representing 184 species in 121 genera of Brassicaceae were used to determine monophyly of tribes and genera, tribal boundaries, and component genera. Parsimony analysis and Bayesian inference suggest that the tribes Camelineae and Arabideae are polyphyletic and should be subdivided into smaller tribes. The study also supports the recent recognition of the new tribes Aphragmeae, Biscutelleae, Buniadeae, Calepineae, Conringieae, Dontostemoneae, Erysimeae, Malcolmieae, Megacarpaeeae, and Turritideae. The data argue for the placement of Borodinia in the tribe Boechereae, Litwinowia and Pseudoclausia in the Chorisporeae, Atelanthera and Streptoloma in the Euclidieae, and Megacarpaea and Pugionium in the Megacarpaeeae, and exclusion of Asperuginoides, Didymophysa, and Ptilotrichum from the Alysseae, Macropodium, Pseudoturritis, and Stevenia from the Arabideae, and Crucihimalaya, Irenepharsus, Pachycladon, and Turritis from the Camelineae. Finally, the findings support the expansion of Stevenia to include both Berteroella and Ptilotrichum, Sterigmostemum to include Oreoloma and one species of Anchonium, Crucihimalaya to include Transberingia and several species of Arabis, and Parrya to include Pseudoclausia. The data also suggest that Calymmatium and Olimarabidopsis may be congeneric.

A revision of the Allium species of the section Molium in the Canary Islands is presented. As part of the phylogenetic revision
of the Eurasian representatives of the subgenus Amerallium we found large disagreements in the nomenclature and
taxonomy of Allium roseum in the floristic publications on the flora of the Canary Islands. At least four species of the section
Molium are mentioned for the flora of the Canary Islands: Allium roseum, A. subvillosum, A. subhirsutum and A. trifoliatum. To learn more about the phylogenetic relationships within a group of closely related species of the section Molium, we used maximum parsimony and Bayesian analyses of combined nuclear (ITS—internal transcribed and ETS—external transcribed spacers of rRNA genes) and three chloroplast (rpl32-trnL and trnL-trnF intergenic spacers and rps16 intron) datasets of 7 taxa. For comparison of the relationships of A. canariense populations between the islands we used the ISSR method. We found that only one species of the section Molium occurs in the Canary Islands—the endemic species Allium canariense, closely related to Allium subvillosum. Independence of this new species has been confirmed by morphological and molecular features. Discussion on phylogeny, origin and geographic distribution is provided.

The phytogeography of the genus Allium in Siberia and Mongolia is described, based on the numerical classification of a matrix of 56 species and 769 Operational Geographic Uniis (OGUs). Two main diversity centers can be detected, the Altai-Tuva region and southeastern Siberia, which can be further subdivided into 4 subcenters: Altai Mts., Tuva Mts., southern Baikal and Dahuria. The first three subcenters. located in southern Siberia, are rich in endemic species, which are mostly bound to semi-arid environments such as montane steppes and alpine vegetation. These old, isolated mountain ranges constitute the main refugial centers for the Allium flora of Siberia and Mongolia. The Tuva subcenter, rich in endemics and poor in polyploid species, seems to be the most conservative area; the south Baikal region, much richer in polyploid species, appears as an important center af speciation.