Search

Plant species diversity may be considerably underestimated, especially in evolutionarily complex genera and in diversity hotspots that have enabled long‐term species persistence and diversification, such as the Balkan Peninsula. Here, we address the topic of underexplored plant diversity and underlying evolutionary and biogeographic processes by investigating the hygrophytic mountain species complex of Cardamine acris s.l. distributed in the Balkans (three subspecies within C. acris) and northwestern Anatolia (C. anatolica). We performed a series of phylogenetic and phylogeographic analyses based on restriction‐site associated DNA sequencing (RADseq) and target enrichment (Hyb‐Seq) data in combination with habitat suitability modelling. We found C. anatolica as a clade nested within the Balkan C. acris, probably resulting from a founder event, and uncovered three allopatric cryptic lineages within C. acris subsp. acris, allowing us to recognise a total of six entities in this complex. We observed the deepest genetic split within C. acris subsp. acris in the western Balkans, which was at odds with taxonomy and showed no distribution gap. We inferred vicariance as the most likely process for population divergence in the Balkans, accompanied by gene flow between the recognised entities, which was consistent with the modelled habitat suitability dynamics. Furthermore, we discovered several polyploid populations in C. acris, representing both pure intra‐ and inter‐lineage hybrid polyploids, but detected only minor traces of hybridization with related congeners. Overall, our results illustrate that diverse evolutionary processes may influence the history of mountain plant species in the Balkan Peninsula, including vicariance, reticulation, polyploidization and cryptic diversification. [ABSTRACT FROM AUTHOR]

Alyssum rossetii is recorded for the first time in Spain from a single locality in the Pyrenees. After the type locality in the Valpelline valley (Pennine Alps, Italy), it is only the second known locality of this species. Morphology, diploid chromosome number (2n = 16), relative genome size, and ITS sequences confirm that the Pyrenean plants are conspecific with the Alpine ones and should be classified as A. rossetii. Phylogenetic analyses placed A. rossetii within the clade of A. sect. Gamosepalum comprising species from Turkey and demonstrated that A. rossetii is only distantly related to other Alyssum species occurring in the Pyrenees and adjacent regions: A. alyssoides, A. cacuminum, A. collinum, A. fastigiatum, A. granatense, A. montanum, and A. simplex. An identification key to all Alyssum species known from the Pyrenees is presented. Citation: Š aniel S Mártonfiová L & Zozomová-Lihová J 2024: An unex ected occurrence of Al ssum rossetii (Brassicaceae) in the Pyrenees, a new species for the Spanish flora. – Willdenowia 53: 297–307 Version of record first published online on 29 January 2024. [ABSTRACT FROM AUTHOR]

The European Alps show a high degree of endemism associated mainly with the location of glacial refugia and environmental heterogeneity. Several Alpine endemics have evolved in the genus Alyssum. Here we study perennial Alyssum populations in the Western Alps, mainly distributed in the Aosta Valley region, which hosts high species diversity, although endemics are rare. We addressed the recently described stenoendemic A. rossetii and taxonomically uncertain populations usually attributed to A. montanum s.s. to clarify their phylogenetic position and morphological differentiation. The latter entity has been shown to be distinct from A. montanum s.s. and is described as a new species, Alyssum cognense , phylogenetically placed in the A. montanum–A. repens species complex. Both morphological and genetic patterns revealed that its closest relative occurs in the central Balkans. We present detailed ecological characteristics and morphological differentiation of A. cognense sp. nov. from its relatives and geographically closest species and speculate on its biogeographic origin. Genetic patterns (reduced diversity and nestedness) suggest long-distance dispersal from the central Balkan Peninsula. The second studied species, A. rossetii , is phylogenetically distant and belongs to the mainly Asian Alyssum section Gamosepalum lineage, which includes few representatives in southern and eastern Europe. The phylogenetically closest species of A. rossetii are Anatolian endemics, so this extreme disjunction remains puzzling. The present study illustrates the need for in-depth taxonomic and phylogenetic studies, even in well-explored Alpine regions, and also shows that the processes underlying the evolution of endemics can be complex and poorly understood. [ABSTRACT FROM AUTHOR]

Copyright of Botanica Serbica is the property of University of Belgrade, Institute of Botany & Botanical Garden Jevremovac and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reproductive behaviour and the pathways of gene flow among ploidy levels were studied experimentally in Taraxacum sect. Ruderalia. Diploid, triploid and tetraploid individuals were sampled from mixed diploid -- polyploid natural populations. 136 experimental hybridizations between the plants of different ploidy levels were performed. Seeds resulting from these crosses, those obtained from isolated anthodia as well as from open pollinated anthodia (both from cultivated and wild plants) were subjected to the flow-cytometric seed screening (FCSS) to determine ploidy levels in the progeny and to infer breeding behaviour of maternal plants. Three possible pathways of the gene flow were studied: (A) fertilization of sexuals by pollen of apomicts, (B) BIII hybrid formation, (C) facultative apomixis. Diploid maternal plants when experimentally crossed with triploid pollen donors produced diploids and polyploid progeny, while when pollinated with a mixture of the pollen of diploids and triploids or insect pollinated, no polyploids were discovered. It seems that in the mixture with the pollen of diploids, the pollen of triploids is ineffective. Tetraploids produce hybrids much easier with diploid mothers and their role in wild populations requires further study. Triploid mothers, even those with subregular pollen did not show traces of facultative apomixis. BIII hybrids were present in the progeny of both triploids and tetraploids, in tetraploids in quite high percentages (up to 50% of the progeny in some crosses). [ABSTRACT FROM AUTHOR]