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Abstract: The halophyte model plant Eutrema salsugineum (Brassicaceae) disjunctly occurs in temperate to subarctic Asia and North America. This vast, yet extremely discontinuous distribution constitutes an ideal system to examine long‐distance dispersal and the ensuing accumulation of deleterious mutations as expected in expanding populations of selfing plants. In this study, we resequenced individuals from 23 populations across the range of E. salsugineum. Our population genomic data indicate that E. salsugineum migrated “out of the Altai region” at least three times to colonize northern China, northeast Russia and western China. It then expanded its distribution into North America independently from northeast Russia and northern China, respectively. The species colonized northern China around 33.7 thousand years ago (kya) and underwent a considerable expansion in range size approximately 7–8 kya. The western China lineage is likely a hybrid derivative of the northern China and Altai lineages, originating approximately 25–30 kya. Deleterious alleles accumulated in a stepwise manner from (a) Altai to northern China and North America and (b) Altai to northeast Russia and North America. In summary, E. salsugineum dispersed from Asia to North America and deleterious mutations accumulated in a stepwise manner during the expansion of the species’ distribution. [ABSTRACT FROM AUTHOR]

Erysimum includes 150-350 species distributed in the Northern Hemisphere, with Eurasia being the centre of greatest diversity. It is well known for its taxonomic complexity as a result of overlapping morphological characters. We present the first densely sampled phylogenetic analysis of Erysimum using internal transcribed spacer ( ITS) DNA sequences from c. 85% of the species (117 for the first time), representing the full range of morphological variation and geographical distribution. We used several approaches to reconstruct phylogenetic relationships, dating of diversification and patterns of evolution of morphological characters in the genus. Ancestral-state reconstructions of four morphological diagnostic characters were performed using maximum parsimony, maximum likelihood and Bayesian methods. Our phylogenetic framework strongly supports the monophyly of Erysimum and recovers some well-supported clades that are geographically, rather than morphologically, correlated. Our study confirms the placement of Erysimum in lineage I and reveals two Malcolmia spp. ( M. maritima and M. orsiniana) as its sister taxa. The results suggest that the biennial duration and caespitose habit (vs. annual or perennial duration and herbaceous or woody habit) and large, yellow, glabrous (vs. small, non-yellow, pubescent) petals are ancestral in Erysimum. The ancestral-state reconstruction results show that annual vs. perennial and woody vs. herbaceous features have been independently derived several times. The dating analyses suggest an early radiation of Erysimum during the late Pliocene or early Pleistocene. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 497-522. [ABSTRACT FROM AUTHOR]

The new species Draba alshehbazii Klimeš & D.German sp. nov. (Brassicaceae) from eastern Ladakh, India is described and illustrated. The species grows from 5310 to 6000 m in the subnival zone on solifluction soils. It resembles Draba oreades, with which it often occurs but is distinguished from all other Draba species in Ladakh by its yellow petals and tomentose indumentum. Differences from the eastern Tibetan Draba involucrata are discussed. A simplified key for the identification for Draba species in Ladakh is provided. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158, 749–754. [ABSTRACT FROM AUTHOR]

The article focuses on the proposals to conserve the use of Odontarrhena obovata (Alyssum obovata) name over Odontarrhena microphylla name for Siberian plants. It states that odontarrhena name was proposed to conserve as it was the widely used and validated earlier name for the plants. It says that compared to A. obovata, odontarrhena microphylla was less known and is only used for three flora types in Siberia. Moreover, microphylla was not validly published as name of the plants.

Clade E, or the Hesperis clade, is one of the major Brassicaceae (Crucifereae) clades, comprising some 48 genera and 351 species classified into seven tribes and is distributed predominantly across arid and montane regions of Asia. Several taxa have socioeconomic significance, being important ornamental but also weedy and invasive species. From the comparative genomic perspective, the clade is noteworthy as it harbors species with the largest crucifer genomes but low numbers of chromosomes (n = 5-7). By applying comparative cytogenetic analysis and whole-chloroplast phylogenetics, we constructed, to our knowledge, the first partial and complete cytogenetic maps for selected representatives of clade E tribes and investigated their relationships in a family-wide context. The Hesperis clade is a well-supported monophyletic lineage comprising seven tribes: Anchonieae, Buniadeae, Chorisporeae, Dontostemoneae, Euclidieae, Hesperideae, and Shehbazieae. The clade diverged from other Brassicaceae crown-group clades during the Oligocene, followed by subsequent Miocene tribal diversifications in central/southwestern Asia. The inferred ancestral karyotype of clade E (CEK; n = 7) originated from an older n = 8 genome, which also was the purported progenitor of tribe Arabideae (KAA genome). In most taxa of clade E, the seven linkage groups of CEK either remained conserved (Chorisporeae) or were reshuffled by chromosomal translocations (Euclidieae). In 50% of Anchonieae and Hesperideae species, the CEK genome has undergone descending dysploidy toward n = 6 (-5). These genomic data elucidate early genome evolution in Brassicaceae and pave the way for future whole-genome sequencing and assembly efforts in this as yet genomically neglected group of crucifer plants. [ABSTRACT FROM AUTHOR]

Background and Aims Aubrieta is a taxonomically difficult genus from the Brassicaceae family with approximately 20 species centred in Turkey and Greece. Species boundaries and their evolutionary history are poorly understood. Therefore, we analysed bio- and phylogeographic relationships and evaluated morphological variation to study the evolution of this genus. Methods Phylogenetic analyses of DNA sequence variation of nuclear-encoded loci and plastid DNA were used to unravel phylogeographic patterns. Morphometric analyses were conducted to study species delimitation. DNA sequence-based mismatch distribution and climate-niche analyses were performed to explain various radiations in space and time during the last 2·5 million years. Key Results Species groups largely show non-overlapping distribution patterns in the eastern Mediterranean and Asia Minor. We recognized 20 species and provide evidence for overlooked species, thereby highlighting taxonomical difficulties but also demonstrating underexplored species diversity. The centre of origin of Aubrieta is probably Turkey, from which various clades expanded independently towards Asia Minor, south to Lebanon and west to Greece and the Balkans during the Pleistocene. Conclusions Pleistocene climatic fluctuations had a pronounced effect on Aubrieta speciation and radiation during the last 1·1 million years in the Eastern Mediterranean and Asia Minor. In contrast to many other Brassicaceae, speciation processes did not involve excessive formation of polyploids, but displayed formation of diploids with non-overlapping present-day distribution areas. Expansions from the Aubrieta centre of origin and primary centre of species diversity showed adaptation trends towards higher temperature and drier conditions. However, later expansion and diversification of taxa from within the second centre of species diversity in Greece started ~0·19 Mya and were associated with a general transition of species adaptation towards milder temperatures and less dry conditions. [ABSTRACT FROM AUTHOR]

The mustard family (Brassicaceae) is a scientifically and economically important family, containing the model plant Arabidopsis thaliana and numerous crop species that feed billions worldwide. Despite its relevance, most phylogenetic trees of the family are incompletely sampled and often contain poorly supported branches. Here, we present the most complete Brassicaceae genus-level family phylogenies to date (Brassicaceae Tree of Life or BrassiToL) based on nuclear (1,081 genes, 319 of the 349 genera; 57 of the 58 tribes) and plastome (60 genes, 265 genera; all tribes) data. We found cytonuclear discordance between the two, which is likely a result of rampant hybridization among closely and more distantly related lineages. To evaluate the impact of such hybridization on the nuclear phylogeny reconstruction, we performed five different gene sampling routines, which increasingly removed putatively paralog genes. Our cleaned subset of 297 genes revealed high support for the tribes, whereas support for the main lineages (supertribes) was moderate. Calibration based on the 20 most clock-like nuclear genes suggests a late Eocene to late Oligocene origin of the family. Finally, our results strongly support a recently published new family classification, dividing the family into two subfamilies (one with five supertribes), together representing 58 tribes. This includes five recently described or re-established tribes, including Arabidopsideae, a monogeneric tribe accommodating Arabidopsis without any close relatives. With a worldwide community of thousands of researchers working on Brassicaceae and its diverse members, our new genus-level family phylogeny will be an indispensable tool for studies on biodiversity and plant biology. • An unparalleled Brassicaceae phylogeny covering nearly all 349 genera is presented • Cytonuclear discordance is omnipresent and a likely sign of rampant hybridization • The family originated during the late Eocene to late Oligocene • Results are used to come up with a new family classification The Brassicaceae family contains the model plant Arabidopsis thaliana and many important crop species. Surprisingly, relationships within the family were poorly known. Hendriks et al. present an unprecedented family phylogeny with representatives from nearly all 349 genera. These results will boost fundamental and applied plant biological research. [ABSTRACT FROM AUTHOR]

Aim Soil pH is considered an important driver of fine-scale plant species richness in terrestrial ecosystems. However, it is unclear to what extent this relationship is influenced by precipitation, which often directly affects both soil pH and species richness. We asked: (1) what is the relationship between fine-scale vascular plant species richness and soil pH in regions with different levels of precipitation and (2) what are the relative effects of soil pH and precipitation on species richness? Location Dry grasslands in eight regions of northern Eurasia. Methods Species richness and soil pH were measured in 1055 10 m × 10 m plots and precipitation values were derived from global datasets. Relationships between variables were explored using general linear models, mixed-effect models and partial regressions. Variation partitioning was used to assess the relative effect of each predictor on species richness. Results In wetter regions, soil pH range was broader, mean species richness was higher and the richness-pH relationship was unimodal. In drier regions, mean soil pH was higher and its range narrower, species richness was on average lower and less variable, and the richness-pH relationship was negative or absent. The richness-pH relationship persisted after controlling for the effect of precipitation, but precipitation, uniquely or together with soil pH, explained more variation in species richness in most regions than did pH alone. Main conclusions The relationship between plant species richness and soil pH in dry grasslands changes from unimodal, through negative, to none with decreasing regional precipitation in Eurasia. However, it seems that the species richness-soil pH relationship in dry grasslands over broad areas is substantially influenced and confounded by precipitation either indirectly, by shortening and shifting the pH gradient, or directly, by decreasing the negative effects of drought stress on richness. [ABSTRACT FROM AUTHOR]

Database of published chromosome numbers and ploidy-level estimates of the tribe Alysseae is presented, together with the revised generic concept and the list of accepted names, to reflect the most recent taxonomic and phylogenetic studies in Alysseae. It is available on-line at . The tribe encompasses 24 genera and 277 species. Chromosome numbers and/or ploidy levels are known for 171 out of 297 recognized taxa. Of these, 95 (55.6 %) taxa are diploids, 43 (25.1 %) are polyploids, and 33 (19.3 %) involve both diploids and polyploids. The most common base chromosome number in the tribe is x = 8 and less frequent is x = 7. The highest variation in base chromosome numbers ( x = 7, 8, 11, 15) is found in the genus Hormathophylla. A key to all genera and descriptions of the two new genera Cuprella and Resetnikia are presented. Many new nomenclatural combinations, mainly in the re-established Odontarrhena (77), are proposed. [ABSTRACT FROM AUTHOR]

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods 1,2 . A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome 3,4 . Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins 5-7 . However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes 8 . This 15-fold increase in genus-level sampling relative to comparable nuclear studies 9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade., (© 2024. The Author(s).)

The establishment of Arabidopsis as the most important plant model has also brought other crucifer species into the spotlight of comparative research. While the genus Capsella has become a prominent crucifer model system, its closest relative has been overlooked. The unispecific genus Catolobus is native to temperate Eurasian woodlands, from eastern Europe to the Russian Far East. Here, we analyzed chromosome number, genome structure, intraspecific genetic variation, and habitat suitability of Catolobus pendulus throughout its range. Unexpectedly, all analyzed populations were hypotetraploid (2 n = 30, ~330 Mb). Comparative cytogenomic analysis revealed that the Catolobus genome arose by a whole-genome duplication in a diploid genome resembling Ancestral Crucifer Karyotype (ACK, n = 8). In contrast to the much younger Capsella allotetraploid genomes, the presumably autotetraploid Catolobus genome (2 n = 32) arose early after the Catolobus / Capsella divergence. Since its origin, the tetraploid Catolobus genome has undergone chromosomal rediploidization, including a reduction in chromosome number from 2 n = 32 to 2 n = 30. Diploidization occurred through end-to-end chromosome fusion and other chromosomal rearrangements affecting a total of six of 16 ancestral chromosomes. The hypotetraploid Catolobus cytotype expanded toward its present range, accompanied by some longitudinal genetic differentiation. The sister relationship between Catolobus and Capsella allows comparative studies of tetraploid genomes of contrasting ages and different degrees of genome diploidization., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Farhat, Mandáková, Divíšek, Kudoh, German and Lysak.)

Based on recent achievements in phylogenetic studies of the Brassicaceae, a novel infrafamilial classification is proposed that includes major improvements at the subfamilial and supertribal levels. Herein, the family is subdivided into two subfamilies, Aethionemoideae (subfam. nov.) and Brassicoideae. The Brassicoideae, with 57 of the 58 tribes of Brassicaceae, are further partitioned into five supertribes, including the previously recognized Brassicodae and the newly established Arabodae, Camelinodae, Heliophilodae, and Hesperodae. Additional tribus-level contributions include descriptions of the newly recognized Arabidopsideae, Asperuginoideae, Hemilophieae, Schrenkielleae, and resurrection of the Chamireae and Subularieae. Further detailed comments on 17 tribes in need of clarifications are provided.