Božo Frajman

• PhD
• University of Innsbruck

The Eurasian steppes are the second-largest continuous biome on Earth. Euphorbia glareosa , a member of the Euphorbia nicaeensis alliance, is a widespread species in the macroclimatically defined zonal Pontic steppes and westerly and southerly adjacent extrazonal steppe outposts determined by local climatic, topographic, and edaphic conditions. In...

We explored the diversification of the south‐eastern and eastern European Euphorbia agraria s.l. applying molecular (amplified fragment length polymorphism [AFLP] fingerprinting and sequencing of the nuclear ribosomal internal transcribed spacer [ITS]), cytogenetic (relative genome size [RGS] estimations) and morphometric methods. The AFLP data, an...

Astragalus sect. Caprini includes 300 species occurring in dry habitats from lowlands to the alpine belt from northwestern Africa and western Europe in the West to Central Asia in the East. In Europe, approximately a dozen taxa occur and our recent phylogenomic study (Maylandt et al., 2025) revealed a genetically divergent lineage from the mountain...

The Alborz Mountains represent an area of endemism within the Irano-Turanian floristic region. They are particularly rich in the number of species belonging to Euphorbia subgenus Esula (leafy spurges). Here, we present a new annual leafy spurge discovered in the area. Morphologically and ecologically, it resembles annual Euphorbia szovitsii, the so...

Luzula sect. Luzula is a taxonomically challenging group of angiosperms, whose evolutionary history has been shaped by polyploidy and agmatoploidy (fragmentation of holocentric chromosomes). Several species with different chromosome sizes and numbers, ranging from diploids to hexaploids, occur above timberline in the Eastern Alps. Species of differ...

Grasslands cover approximately 30% of all land area and represent one of the most extensive and diverse ecosystems of the world. One of the largest globally distributed genera dominating various types of grasslands is Festuca (Loliinae, Poaceae). In this study, we disentangle the origin and diversification of early divergent lineages within fine‐le...

The Eurasian steppes are among the largest and most threatened biomes on Earth. During cold periods of the Pleistocene, the zonal Eurasian steppes had a much larger extent as compared to interglacial periods, and repeatedly expanded into large areas of present-day forested temperate Europe. Conversely, during warm periods, forest expansion recurren...

This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: mycorrhizal fungus Russula sapinea, parasitic fungus Podosphaera polemonii, saprotrophic fungi Ophiognomonia mela-nostyla and Plagiostoma apiculatum, diatom alga Nitzschia reskoi, stonewort Nitellopsis obtusa, liverwort Mannia triandra, moss...

ABSTRACT: This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: mycorrhizal fungus Russula sapinea, parasitic fungus Podosphaera polemonii, saprotrophic fungi Ophiognomonia melanostyla and Plagiostoma apiculatum, diatom alga Nitzschia reskoi, stonewort Nitellopsis obtusa, liverwort Mannia trian...

European wild carnations (Dianthus) are represented by a high number of taxa organized in unresolved taxonomies. Particularly, taxa belonging to the Dianthus virgineus L. complex in the Central Mediterranean have been delimited mainly with qualitative morphological data and still await quantitative investigations, which are vital to understand boun...

Polyploidy can cause differences in phenotypic and physiological traits among different cytotypes of the same species. Polyploids may have larger organs or occupy different ecological niches than their diploid counterparts, therefore they are hypothesized to have larger distributions or prosper in stressful environments, such as higher elevations....

The Mediterranean Basin is a hotspot of animal and plant diversity. Contrary to the Balkan and Iberian Peninsulas that were subject of many phylogeographic studies in past decades, the Apennine Peninsula and, in particular, the diversification of its flora has been neglected in contemporary phylogenetic studies. The few available studies showed a c...

Deciduous forests form the dominant natural vegetation of Europe today, but were restricted to small refugia during Pleistocene cold stages, implying an evolutionary past shaped by recurrent range contractions and expansions. Cold‐stage forest refugia were probably widespread in southern and central Europe, with the northwestern Balkan Peninsula be...

High levels of phenotypic plasticity are thought to be inherently costly in stable or extreme environments, but enhanced plasticity may evolve as a response to new environments and foster novel phenotypes. Heliosperma pusillum forms glabrous alpine and pubescent montane ecotypes that diverged recurrently and polytopically (parallel evolution) and c...

The Mediterranean Basin is renowned for its extremely rich biota and is considered as one of the 25 Global Biodiversity Hotspots, but its diversity is not homogeneously distributed. Outstanding in the number of (endemic) species are the Ligurian Alps (Italy). At the foot of the Ligurian Alps, little above the Mediterranean Sea, a disjunct occurrenc...

Deciduous forests form the dominant natural vegetation of Europe today, but were restricted to small refugia during Pleistocene cold stages, implying an evolutionary past shaped by recurrent range contractions and expansions. Cold-stage forest refugia were probably widespread in southern and central Europe, with the northwestern Balkan Peninsula be...

Simple Summary The genus Sorbus (whitebeams, rowans, and service trees) encompasses forest trees and shrubs characterised by exceptional diversity resulting from the interplay of polyploidisation, hybridization, and apomixis. The spatiotemporal processes driving Sorbus diversification remain poorly understood. This research aims to provide insights...

Polyploidisation, agmatoploidy and symploidy have driven the diversification of Luzula sect. Luzula. Several morphologically very similar species with different karyotypes have evolved, but their evolutionary origins and relationships are unknown. In this study, we used a combination of relative genome size and karyotype estimations as well amplifi...

The Mediterranean Basin is one of the most biodiverse areas in the world, harboring 25,000 plant species, of which 60% are endemic. Some of them have narrow distributions, such as Euphorbia orphanidis, which is only known from alpine screes on Mt. Parnassos in Greece. Its exact distribution in this mountain was, however, poorly known, and its phylo...

Polyploidization is a key factor in the diversification of flowering plants, but appears to be of only minor importance in the evolution of Euphorbia subgenus Esula. An exception is Euphorbia section Esula, including c. 100 species, many of which are widespread, but several have restricted distribution areas. We used ITS sequencing and relative gen...

The ant Plagiolepis taurica Santschi, 1920 (Hymenoptera, Formicidae) is a typical species of the Eurasian steppes, a large grassland dominated biome that stretches continuously from Central Asia to Eastern Europe and is represented by disjunct outposts also in Central and Western Europe. The extent of this biome has been influenced by the Pleistoce...

The Mediterranean Basin is an important biodiversity hotspot and one of the richest areas in the world in terms of plant diversity. Its flora parallels in several aspects that of the Eurasian steppes and the adjacent Irano-Turanian floristic region. The Euphorbia nicaeensis alliance spans this immense area from the western Mediterranean to Central...

Genome size (GS) is an important characteristic that may be helpful in delimitation of taxa, and multiple studies have shown correlations between intraspecific GS variation and morphological or environmental factors, as well as its geographical segregation. We estimated a relative GS (RGS) of 707 individuals from 162 populations of Dianthus sylvest...

High levels of phenotypic plasticity are thought to be inherently costly in stable or extreme environments, but enhanced plasticity may evolve as a response to novel environments and foster adaptation. Heliosperma pusillum forms pubescent montane and glabrous alpine ecotypes that diverged recurrently and polytopically ( parallel evolution ). The sp...

The Balkan Peninsula played an important role in the evolution of many Mediterranean plants and served as a major source for post-Pleistocene colonisation of central and northern Europe. Its complex geo-climatic history and environmental heterogeneity significantly influenced spatiotemporal diversification and resulted in intricate phylogeographic...

Understanding how organisms adapt to the environment is a major goal of modern biology. Parallel evolution ‐ the independent evolution of similar phenotypes in different populations ‐ provides a powerful framework to investigate the evolutionary potential of populations, the constraints of evolution, its repeatability and therefore its predictabili...

The Balkan Peninsula is a hotspot of European biodiversity, harbouring many endemic species. Cerastium decalvans is a heteroploid species endemic to mountainous areas throughout the Balkan Peninsula. It is morphologically extremely variable, and multiple infraspecific taxa have been described. Mostly tetra-, octo- and hexadecaploids have been repor...

Understanding how organisms adapt to the environment is a major goal of modern biology. Parallel evolution - the independent evolution of similar phenotypes in different populations - provides a powerful framework to explore this question. Here, we quantified the degree of gene expression and functional parallelism across replicated ecotype formati...

Aim The Balkan Peninsula has served as source for the colonisation of large parts of Europe after the Pleistocene, but the processes driving the intraspecific diversification within the Balkan Peninsula are much less understood. To fill this gap, we investigated the phylogeography and evolutionary history of three habitat-segregated Cerastium taxa...

Glacial refugia of alpine and subnival biota have been intensively studied in the European Alps but the fate of forests and their understory species in that area remains largely unclear. In order to fill this gap, we aimed at disentangling the spatiotemporal diversification of disjunctly distributed black hellebore Helleborus niger (Ranunculaceae)....

The Caucasus is one of the richest areas in the world in terms of animal and plant diversity, harbouring 6400 plant species. As a part of the Northern Caucasus, the Stavropol Heights are renowned for their local endemism, highlighted by six species of flowering plants endemic to this area. One of them is the annual species Euphorbia normannii , des...

Southern European mountain ranges have long been recognized as important hotspots of genetic diversity and areas of high endemism. Reflecting the geographical complexity of these mountain ranges, many European high-mountain species exhibit disjunctions on a variety of geographical scales. One of the long-neglected, poorly investigated and unresolve...

We explored the diversification of the southern European Euphorbia verrucosa alliance applying molecular (amplified fragment length polymorphism fingerprinting [AFLP], sequencing of the nuclear ribosomal internal transcribed spacer), karyological (relative genome size estimations, chromosome counts) and morphometric methods. The AFLP data inferred...

The Mediterranean region is one of the 25 biodiversity hotspots, with several species distributed on both sides of the Adriatic Sea, i.e. on the Apennine and the Balkan Peninsulas. One of these is Euphorbia spinosa, distributed in the coastal regions of the Ligurian, Tyrrhenian, Ionian and Adriatic Seas, whereas its closest relative, E. glabriflora...

The European steppes and their biota have been hypothesized to be either young remnants of the Pleistocene steppe belt or, alternatively, to represent relicts of long-term persisting populations; both scenarios directly bear on nature conservation priorities. Here, we evaluate the conservation value of threatened disjunct steppic grassland habitats...

The European steppes and their biota have been hypothesized to be either young remnants of the Pleistocene steppe belt or, alternatively, to represent relicts of long-term persisting populations; both scenarios directly bear on nature conservation priorities. Here, we evaluate the conservation value of threatened disjunct steppic grassland habitats...

The Balkan Peninsula is renowned as a refugium of forest species, which were more widespread in the Tertiary. We here investigated three species from one of the largest genera of flowering plants, Euphorbia, which survived the Pleistocene glaciations in the Balkan Peninsula, but responded differently to Holocene warming. Using ITS sequences, multiv...

Polyploidy is a significant driver of plant diversity and is, along with homoploid hybridisation, widely accepted as a common and important evolutionary force in plants. Here, we employed Amplified Fragment Length Polymorphism (AFLP) fingerprinting, ploidy level and genome size determination via flow cytometry and morphometry in order to disentangl...

The Eastern Mediterranean is considered both a reservoir for plant evolution and a cradle for lineage diversification, but most plant groups from this area remain unstudied. To explore phylogeographic patterns within Eastern Mediterranean Euphorbia myrsinites, covering the area from the Apennines to Central Anatolia, we sequenced nuclear ribosomal...

The Eurasian steppes occupy a significant portion of the worldwide land surface and their biota have been affected by specific past range dynamics driven by ice ages-related climatic fluctuations. The dynamic alterations in conditions during the Pleistocene often triggered reticulate evolution and whole genome duplication events. Employing genomic,...

Polyploidisation—and, additionally, agmatoploidy (concerted fission of chromosomes) in some plant groups—have significantly contributed to the diversification of alpine plant species. Both processes have driven the diversification of Luzula sect. Luzula, leading to a number of different karyotypes, rendering it one of the most intricate plant group...

Applying molecular (AFLP and sequences of nuclear ribosomal ITS), karyological (relative genome size estimations and chromosome counts) and morphometric methods we explored the origin of Italian endemic Euphorbia gasparrinii. AFLP data inferred three phylogeographic groups corresponding to Balkan-Central European-northern Italian E. verrucosa, Ital...

The Andes are an important biogeographic region in South America extending for about 8000 km from Venezuela to Argentina. They are – along with the Patagonian steppes – the main distribution area of ca. 18 polyploid species of Silene sect. Physolychnis. Using nuclear ITS and plastid psbE-petG and matK sequences, flow cytometric ploidy level estimat...

The south-eastern Alps and the southerly adjacent areas are considered an important refugium for plant species during the Pleistocene glaciations; consequently, they harbour many endemic taxa. One of them is Cerastium subtriflorum, which in this area occurs sympatrically with morphologically similar, but more widespread C. sylvaticum. Here, we used...

Next generation sequencing has revolutionised biology. Restriction-associated DNA sequencing (RADseq) has primarily been used to study infraspecific relationships but has also been applied in multi-species phylogenomic analyses. In this study, we used a combination of phylogenomic (with RADseq data) and phylogenetic (with sequences of the nuclear i...

The evolution of species or ecotypes can occur gradually through neutral and adaptive genetic changes. To explore the influence of natural selection during early phases of divergence, morphological and ecological discontinuity and its adaptive significance were investigated in six pairs of alpine and independently evolved montane populations of Hel...

The Balkan Peninsula is a hotspot of European biotic diversity. One of its biogeographically most peculiar but poorly explored regions are the Albanian Alps (Alpet Shqiptare/Prokletije/Accursed Mountains) on the border between Albania, Kosovo and Montenegro, characterised by a high number of endemic species. A poorly known taxon from the Albanian A...

Sesleria (Poaceae) is a species-rich, taxonomically difficult genus due to high morpho-anatomical variability and weak differentiation of many species. It is distributed throughout western Eurasia and North Africa with highest taxonomic diversity on the Balkan Peninsula. Of the more than 40 species only two are diploid, all others are tetra- to dod...

Fig. S1 Proportion of transposable elements in the RADseq dataset. Fig. S2 Ecotype‐specific proportion of transposable elements. Fig. S3 RADseq dataset quality control. Fig. S4 Proportion of loci assigned to putative phyllosphere and contaminant taxa. Fig. S5 Analysis of putative phyllosphere and contaminant taxa by ecotype. Fig. S6 Analysis o...

Several plant and animal species exhibit amphi-Adriatic distributions spanning the Italian and Balkan peninsulas. Such distribution patterns have traditionally been explained mostly by land connections between the two peninsulas during the Messinian salinity crisis (Miocene/Pliocene), but recent studies employing molecular dating pointed to more re...

The mosaic distribution of interbreeding taxa with contrasting ecology and morphology offers an opportunity to study microevolutionary dynamics during ecological divergence. We investigate here the evolutionary history of an alpine and a montane ecotype of Heliosperma pusillum (Caryophyllaceae) in the south‐eastern Alps. From six pairs of geographi...

Gymnospermium is a genus of early spring-flowering tuberous herbaceous plants including c. 12 species distributed from south-eastern Europe to East Asia. For the European and Caucasian populations, different taxonomic concepts have been proposed, ranging from two to five species. We used AFLP and nuclear and plastid DNA sequences (internal transcri...

Evolution is driven by natural selection, favouring individuals adapted in phenotypic traits to the environmental conditions at their growing site. To shed light on ecological and (epi-) genetically based differentiation between Heliosperma pusillum and Heliosperma veselskyi, two reciprocally non-monophyletic, but morphologically and ecologically d...

Out of ca. 700 species belonging to Silene, 15 to 35 were classified in S. sect. Saxifragoideae. This section has its highest diversity on the Balkan Peninsula, which was the most important European Pleistocene refugium. The most widespread of the species is S. saxifraga ranging from the Pyrenees to the Carpathians. Together with ten morphologicall...

Adaptation to dissimilar habitats can trigger phenotypic and genetic differences between populations, which may, in the absence of gene flow, ultimately lead to ecological speciation. Reproductive isolation of diverging populations is a critical step at the onset of speciation. An excellent example for exploring the extent of reproductive isolation...

Background Polyploidy is one of the most important evolutionary pathways in flowering plants and has significantly contributed to their diversification and radiation. Due to the prevalence of reticulate evolution spanning three ploidy levels, Knautia is considered one of the taxonomically most intricate groups in the European flora. On the basis of...

Evolution is driven by natural selection, favouring individuals adapted in morphology and physiology to the environmental conditions at their growing site. Here, we studied environmentally induced and (epi-)genetically based components of divergence of photosynthesis in response to irradiance and temperature and cellular characteristics reflecting...

Premise of the study: Knautia drymeia is a morphologically variable, diploid and tetraploid temperate forest understory species distributed in southeastern Europe and adjacent areas. The species is an excellent system to explore the influence of polypoidy on taxonomic delineations, the role of hybridization among genetically distant populations in...

Luzula sect. Luzula is one of the taxonomically most intricate groups of angiosperms, where diversification is mostly driven by true polyploidy and agmatoploidy (fission of chromosomes) leading to three different karyotypes (whole chromosomes – AL, half-sized chromosomes – BL and quarter-sized chromosomes – CL). Morphologically, the taxa are often...

Cases of parallel ecological divergence in closely related taxa offer an invaluable material to study the processes of ecological speciation. Applying a combination of population genetic and metagenomic tools on a high-coverage RAD sequencing dataset, we test for parallel evolution across six population pairs of Heliosperma pusillum and H. veselsky...

The Alps and the Carpathians are important centres of plant endemism in Europe, but there are fewer phylogenetic studies on the patterns in biodiversity of Carpathian biota than there are for the Alps. Here, we use nuclear ribosomal ITS, the plastid trnT-trnF region and amplified fragment length polymorphism (AFLP) fingerprinting to determine the p...

Amphoricarpos Vis. is an early diverging genus within tribe Cardueae (Carduoideae, Asteraceae), which is disjunctly distributed in the Balkan Peninsula, Anatolia and the Caucasus; the Anatolian and Caucasian taxa are sometimes treated as separate genus Alboviodoxa. We focus on the monophyletic Balkan populations, which have been treated very incons...

The leafy spurges, Euphorbia subgenus Esula, have one of their diversity centres in the Mediterranean, which is considered to be one of the 25 biodiversity hot-spots. The eastern Mediterranean, in particular, is characterized by its high species richness and is therefore considered to be a cradle for lineage diversification. However, the area remai...

Interspecific hybridization, especially when regularly followed by backcrossing (i.e., introgressive hybridization), conveys a substantial risk for many endangered organisms. This is particularly true for narrow endemics occurring within distributional ranges of widespread congeners. An excellent example is provided by the plant genus Knautia (Capr...

Polyploidization has played an important role in the diversification of the genus Sesleria (Poaceae), which comprises c. 48 species and subspecies mostly distributed in Europe. The genus' centre of diversity clearly is the Balkan Peninsula, harbouring about 80% of the species, half of which are endemic to this area. We employed chromosome counts, m...

Background Polyploidisation is one of the most important mechanisms in the evolution of angiosperms. As in many other genera, formation of polyploids has significantly contributed to diversification and radiation of Knautia (Caprifoliaceae, Dipsacoideae). Comprehensive studies of fine- and broad-scale patterns of ploidy and genome size (GS) variati...

Sorbus subgenus Soraria encompasses taxa originating from spontaneous hybridization between members of subgenera Aria and Sorbus disjunctly distributed across Europe and Asia. Using molecular data (amplified fragment length polymorphisms, plastid DNA sequences and nuclear microsatellites), flow cytometry (allowing for the determination of ploidy an...

Alyssum ovirense (Brassicaceae) is disjunctly distributed in the eastern Alps, predominantly occurring in the southern limestone Alps, but with one isolated population on the Hochschwab massif in the northern limestone Alps. The closely related rare and narrow endemic A. wulfenianum is restricted to gravel beds in a few rivers in the southern Alps...

Carex cespitosa L. (Cyperaceae) has been traditionally regarded as widespread in Europe, being reported from most countries. However, its distribution is currently overestimated due to the ambiguous use of the name C. cespitosa, together with frequent taxonomic confusion, mainly with the closely related C. elata All. and C. nigra (L.) Reichard. We...

The Balkan Peninsula belongs to the botanically least explored regions of Europe, even if it is probably Europe's floristically richest area. During several excursions to the western Balkan Peninsula we encountered new and noteworthy localities of rare and endangered plant species and hence present our most significant findings. We discovered a sec...

We report on the occurrence of Orobanche krylowii in the Alpet Shqiptare (Prokletije, Albanian Alps) mountain range in northern Albania (Balkan Peninsula). The species was previously known only from eastern-most Europe (Volga-Kama River in Russia), more than 2500 km away, and from adjacent Siberia and Central Asia. We used morphological evidence as...

A species‐level taxonomic revision of Atocion and Viscaria, based on a recent phylogenetic study, is presented. Atocion includes six species (A. armeria, A. compactum, A. lerchenfeldianum, A. reuterianum, A. rupestre and A. scythicinum), and Viscaria includes three species (V. alpina, V. asterias and V. vulgaris). The highest species diversity is f...

The main aim of our study was to reconstruct the relationships among populations of the taxonomically intricate genus Sesleria Scop. (Poaceae) based on Amplified Fragment Length Polymorphisms (AFLPs) and plastid DNA (trnL-ndhF) sequences. We evaluated the genetic structure of the AFLP data using Bayesian approaches (BAPS), Neighbor-Joining (NJ) ana...

Reconstruction of relationships among populations of the morphologically polymorphic and taxonomically intricate Sesleria rigida sensu Fl. Eur. based on Amplified Fragment Length Polymorphisms (AFLPs) revealed four clearly differentiated genetic groups that did only partly follow recent taxonomic concepts, but were strictly allopatric. While some o...

The leafy spurges, Euphorbia subg. Esula, make up one of four main lineages in Euphorbia. The subgenus comprises about 480 species, most of which are annual or perennial herbs, but with a small number of dendroid shrubs and nearly leafless, pencil-stemmed succulents as well. The subgenus constitutes the primary northern temperate radiation in Eupho...

Analyses of mitotic chromosome numbers and nuclear DNA content were performed for 39 populations of 17 perennial Cerastium taxa from south-eastern Europe. The DNA content ranged from 2C = 2.43 to 8.78 pg, revealing four ploidy levels corresponding to 4x (2n = 36), 8x, 12x and 16x. High-polyploid cytotypes with a greater range of ploidy (up to 2n =...