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The genus Astragalus L. with about 3000 species is the largest genus of flowering plants. It is also the largest genus in the flora of Iran with more than 850 taxa. Astragalus cyclophyllon Beck is an endemic taxon belonging to Astragalus sect. Incani DC. It occurs scattered in the steppe and semi-steppe areas of the western and central parts of Iran. This species is one of the most important forage taxa of Astragalus. According to IUCN criteria it has been classified as a vulnerable taxon in Iran, as it occurs in habitats intensely used by herders for their livestock. Here we evaluate the genetic diversity of the populations of this species in Iran to see whether genetic diversity is high or if reductions have already happened. For this purpose, sampling was done in all geographical areas with A. cyclophyllon populations in Iran. In total, 80 individuals representing 29 populations were studied using 33 quantitative and qualitative morphological characters and 10 inter-simple sequence repeat (ISSR) primers. ISSR revealed 240 bands which all were polymorphic. Neighbor-joining cluster analysis divided the individuals in four groups, Principal Coordinate Analysis and Bayesian population assignment analysis in Structure resulted in three genetic units. Morphological variation showed no correlation with the molecular data. The mean of Gst and Nm indices are 0.516 and 0.468, respectively, which indicate a very high genetic differentiation and low gene flow between the studied populations. According to these results, we conclude that genetic diversity is high in this species and that, therefore, the major threat for A. cyclophyllon is currently not related to inbreeding depression in populations, but might be due to livestock grazing that could change the population demographic structure by reducing regular establishment of new offspring.

A new section of Astragalus from Mt. Alvand, W Iran, was recognized namely Astragalus sect. Elvendia Bagheri & Maassoumi, sect. nov., which is described here based on A. leucargyreus Bornm. A full description and diagnosis of the new section are given and taxonomic relationships of the section and its allied taxa are discussed. Molecular phylogenetic data obtained from the nuclear ribosomal DNA internal transcribed spacer (ITS) region as well as plastid ycf1 and matK genes strongly support that the species of the new section is separated from sections Hymenostegis and Adiaspastus, where A. leucargyreus was placed before, and forms a distinct clade. In addition, we discuss the floristic, endemism, and conservation status of the Mt. Alvand region (type locality of the new section). Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2022.2036846 .

Safflower (Carthamus tinctorius) is a source of high-quality edible oil growing in moisture-limited environments. Despite its economic importance, the relationships to close wild species in Carthamus and the presence and relationships of ecotypes within safflower are still not fully clarified. Here we use genotyping-by-sequencing to identify the wild progenitor of C. tinctorius, infer phylogenetic relationship within series Carthamus and identify groups of closely related lineages within cultivated safflower. Phylogenetic and population genetic analyses found C. palaestinus to be the closest relative and single progenitor of C. tinctorius, which confirms the Levant as the area of domestication of the crop. Flow cytometry showed all analyzed samples of C. oxyacantha, C. palaestinus and C. tinctorius to be diploid (2n = 2x = 24) with 2C genome sizes of 2.4 to 2.7 pg. Analyses of a set of 114 worldwide distributed safflower accessions arrived at two to five genetic groups, which showed, however, no correlation with the geographic origins of these accessions. From this, we conclude that the trade of safflower seeds resulted in multiple introductions of genotypes from the Levant to other areas with suitable climate conditions for the plant, as well as exchange of genotypes among these areas.

The geographical origin of watermelon (Citrullus lanatus) remains debated. While a first hypothesis suggests the center of origin to be West Africa, where the endemic sister species C. mucosospermus thrives, a second hypothesis suggests northeastern Africa where the white‐fleshed Sudanese Kordophan melon is cultivated. In this study, we infer biogeographical and haplotype genealogy for C. lanatus, C. mucosospermus, C. amarus, and C. colocynthis using noncoding cpDNA sequences (trnT‐trnL and ndhF‐rpl32 regions) from a global collection of 135 accessions. In total, we identified 38 haplotypes in C. lanatus, C. mucosospermus, C. amarus, and C. colocynthis; of these, 21 were found in Africa and 17 appear endemic to the continent. The least diverse species was C. mucosospermus (5 haplotypes) and the most diverse was C. colocynthis (16 haplotypes). Some haplotypes of C. mucosospermus were nearly exclusive to West Africa, and C. lanatus and C. mucosospermus shared haplotypes that were distinct from those of both C. amarus and C. colocynthis. The results support previous findings that revealed C. mucosospermus to be the closest relative to C. lanatus (including subsp. cordophanus). West Africa, as a center of endemism of C. mucosospermus, is an area of interest in the search of the origin of C. lanatus. This calls for further historical and phylogeographical investigations and wider collection of samples in West and northeastern Africa.

As a result of recent botanical expeditions to the north of Iran, we describe here a new endemic Allium species from Gilan province named Allium gilanense. Molecular and morphological data indicate that it belongs to Allium sect. Codonoprasum. We provide a morphological description, comparing Allium gilanense with the closest relative taxa A. lenkoranicum and A. paniculatum, the preliminary karyotype of the new species, and molecular phylogenetic data derived from the nuclear ribosomal DNA internal transcribed spacers (ITS) and the chloroplast intergenic spacer trnH-psbA. The chromosome number of the new species is 2n = 16 with 0-3 B chromosomes.

Background and aims – Narrow endemics, characterized by small distribution areas and small effective population sizes are prone to extinction due to low genetic variation caused by genetic bottlenecks and drift together with the danger of habitat loss. Astragalus subrecognitus is an endemic species that only occurs in northwestern Iran in mountain steppe at higher elevations above the Qezel Ozan River in the province Zanjan. Methods – In this study, we investigated the genetic structure of the populations of A. subrecognitus using inter simple sequence repeats (ISSR) and sequence-related amplified polymorphism (SRAP) as molecular markers.Key results – We detected two genetic groups, which do however not concur with the geographic origins east and west of the Qezel Ozan River. Extant gene flow between these populations is rather unlikely given their distance of c. 70 km and the lack of suitable habitats for this species in lower areas of the valley in between. Conclusions – From this we conclude that we see an older pattern of geographic isolation that was followed by an exchange of genotypes during a time when migration through the valley was possible. Still, admixture between both genetic clusters was found only in one individual, indicating that broadening of allelic diversity by hybridization between individuals belonging to different genetic clusters might be a slow process. Due to the small size of the population, sparse inhabited area, and also very slow or even lack of regeneration in some places we consider A. subrecognitus according to IUCN Red List criteria as ‘endangered’ species.

The cultivation and domestication of plants are human-driven processes that change the biology and attributes of a plant. Ipheion uniflorum is a bulbous geophyte known as Spring Starflower whose cultivation dates back to the first half of the 19th century. At least seven cultivars have been developed from natural stands. However, comparative analyses of wild and cultivated materials are largely missing. In the present study, we provide a morphological evaluation and analyses of the cytological and genetic variability of I. uniflorum that reveal significant levels of differentiation and evidence of artificial selection in the Spring Starflower. Distinctive phenotypic characters in cultivated materials that are rarely found or lacking in wild plants and natural populations, such as pink or violet flowers, together with its reduced heterozygosity and starting genetic differentiation support the view of early mechanisms of domestication acting upon Spring Starflower plants. The probable geographic origin of the cultivated forms is discussed together with perspectives for plant breeding.

The post-Miocene climatic histories of arid environments have been identified as key drivers of dispersal and diversification. Here, we investigate how climatic history correlates with the historical biogeography of the Atacama Desert genus Cristaria (Malvaceae). We analyze phylogenetic relationships and historical biogeography by using next-generation sequencing (NGS), molecular clock dating, Dispersal Extinction Cladogenesis and Bayesian sampling approaches. We employ a novel way to identify biogeographically meaningful regions as well as a rarely utilized program permitting the use of dozens of ancestral areas. Partial incongruence between the established taxonomy and our phylogenetic data, argue for a complex historical biogeography with repeated introgression and incomplete lineage sorting. Cristaria originated in the central southern part of the Atacama Desert, from there the genus colonized other areas from the late Miocene onwards. The more recently diverged lineages appear to have colonized different habitats in the Atacama Desert during pluvial phases of the Pliocene and early Pleistocene. We show that NGS combined with near-comprehensive sampling can provide an unprecedented degree of phylogenetic resolution and help to correlate the historical biogeography of plant communities with cycles of arid and pluvial phases.

Speciation proceeds through mechanisms that promote reproductive isolation and shape the extent of genetic variation in natural populations, and thus its study is essential to understand the evolutionary processes leading to increased biodiversity. Chromosomal rearrangements are known to facilitate reproductive isolation by hybrid sterility and favour speciation events. The genus Ipheion (Amaryllidaceae, Allioideae) is unique as its species exhibit a remarkable karyological variability but lack population-level genetic data. To unveil the diversification processes acting upon the formation of new lineages within Ipheion in the Pampas of South America, we combined morphology and karyology approaches with genotyping-by-sequencing. Our phylogenomic and population genomics results supported the taxonomic division of Ipheion into three morphological and genetically well-differentiated groups. The origin of Ipheion uniflorum was traced back to its current southern distribution area in the southern Pampean region (in Argentina), from where it had expanded to the north reaching Uruguay. Our results further suggested that chromosome rearrangements and ploidy shifts had triggered speciation events, first during the origin of I. uniflorum and later during its subsequent diversification into I. recurvifolium and I. tweedieanum, in both cases reinforced by extrinsic factors and biogeographical settings. The current study illustrates the analytical power of multidisciplinary approaches integrating phylo- and population genomics with classic analyses to reveal evolutionary processes in plants. Fil: Sassone, Agostina Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina. Leibniz Institute of Plant Genetics and Crop Plant Research; Alemania Fil: Hojsgaard, Diego H.. Leibniz Institute of Plant Genetics and Crop Plant Research; Alemania Fil: Giussani, Liliana Mónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina Fil: Brassac, Jonathan. Leibniz Institute of Plant Genetics and Crop Plant Research; Alemania Fil: Blattner, Frank R.. Leibniz Institute of Plant Genetics and Crop Plant Research; Alemania

Astragalus is with nearly 3000 described species the largest genus of flowering plants. So far analyses of pollen characters have only been conducted for a few species of the groups within ...

Constituting one of Earth’s major biomes, steppes are characterised by naturally treeless extra-tropical vegetation. The formation of the Eurasian steppe belt, the largest steppe region in the world, began in Central Asia during the Neogene. In the glacial stages of the Pleistocene, steppe displaced forest vegetation, which in turn recolonised the area during the warmer interglacial periods, thus affecting the distribution of plants adapted to these habitats. Krascheninnikovia ceratoides (Chenopodiaceae) is a plant characteristic of dry steppe and semi-desert formations. Earlier studies showed that the ancestor of this autochthonous steppe element originated in Central Asia during the Miocene/Pliocene, i.e., in the same region and at the same time as the first appearance of steppe vegetation. However, as the extant lineages of Krascheninnikovia ceratoides diversified only 2.2 ± 0.9 Mya, it may represent a modern element of current dry steppe and semi-desert formations, rather than a component of the first steppe precursors of the Miocene. As such, it may have capitalised on the climatic conditions of the cold stages of the Quaternary to expand its range and colonise suitable habitats outside of its area of origin. To test this hypothesis, phylogeographic methods were applied to high-resolution genotyping-by-sequencing data. Our results indicate that Krascheninnikovia originated in western Central Asia and the Russian Altai, then spread to Europe in the West, and reached North America in the East. The populations of eastern Central Asia and North America belong to the same clade and are genetically clearly distinct from the Euro-Siberian populations. Among the populations west of the Altai Mountains, the European populations are genetically distinct from all others, which could be the result of the separation of populations east and west of the Urals caused by the Pleistocene transgressions of the Caspian Sea.

The geographical origin of watermelon (Citrullus lanatus) remains debated. While a first hypothesis suggests the center of origin to be West Africa, where the endemic sister species C. mucosospermus thrives, a second hypothesis suggests northeastern Africa where the white‐fleshed Sudanese Kordophan melon is cultivated. In this study, we infer biogeographical and haplotype genealogy for C. lanatus, C. mucosospermus, C. amarus, and C. colocynthis using noncoding cpDNA sequences (trnT‐trnL and ndhF‐rpl32 regions) from a global collection of 135 accessions. In total, we identified 38 haplotypes in C. lanatus, C. mucosospermus, C. amarus, and C. colocynthis; of these, 21 were found in Africa and 17 appear endemic to the continent. The least diverse species was C. mucosospermus (5 haplotypes) and the most diverse was C. colocynthis (16 haplotypes). Some haplotypes of C. mucosospermus were nearly exclusive to West Africa, and C. lanatus and C. mucosospermus shared haplotypes that were distinct from those of both C. amarus and C. colocynthis. The results support previous findings that revealed C. mucosospermus to be the closest relative to C. lanatus (including subsp. cordophanus). West Africa, as a center of endemism of C. mucosospermus, is an area of interest in the search of the origin of C. lanatus. This calls for further historical and phylogeographical investigations and wider collection of samples in West and northeastern Africa., While the origin of watermelon is still debated, two endemic close relative are separately found in northeastern Africa and West Africa. Our paper presents the current chloroplast haplotypes distribution to infer the possible colonization route of watermelon using two cultivated and two wild relatives gathered from four continents.

Background: Non-Iranian Primary Tritipyrum (2n=6x=42, AABBEbEb) set seed after Triticale (2n=6x=42, AABBRR) and Tritordeum (2n=6x=42, AABBHcHc) but, due to a few undesirable agronomic traits, it cannot fulfil the commercial expectations of farming. Objectives: To remove these deficiencies, six hexaploid Tritipyrum lines were crossed with four Iranian bread wheat cultivars which led to the production of 107 (F1), 479 (F2), 768 (F3), and 1539 (F4) Iranian Secondary Tritipyrum Genotypes (ISTG) seeds. This study was carried out for selecting the plants potentially carry the 5Eb chromosome/s and are good candidates for salt tolerant by GISH and RFLP markers. Materials and Methods: The procedure involved extracting the total DNA content of 209 plants, including non-Iranian primary Tritipyrum lines, Iranian wheat cultivars, Chinese Spring addition, and substitution lines for 5Eb and Iranian secondary Tritipyrum genotypes (ISTG: F1, F2, F3, F4). Genomic in situ Hybridization (GISH) on mitotic spreads of fertile new Iranian secondary Tritipyrum genotypes (ISTG) was carried out to demonstrate the feasibility of single Eb chromosomes. There were three trials of 18 Fragment Length Polymorphism (AFLP) EcoRI/MseI primers to identify the presence of the 5Eb chromosome in 105 ISTG plants, along with four wheat addition lines and substitution lines for the 5Eb chromosome. Results: GISH on mitotic spreads demonstrated the feasibility of producing 75 plants out of 105 fertile new Iranian secondary Tritipyrum genotypes (ISTG) with 0-14 single Eb chromosomes. Among the mentioned markers, only the E36/M59 marker showed 43, 50, 30 and 47 identical bands, respectively, in contrast to 53 expected bands in all plants with the 5Eb chromosome which indicated 21, 33, 9 and 6 out of 75 ISTG plants, respectively, with the 5Eb chromosome. Conclusion: This study indicated that 69 ISTG Tritipyrum plants were potentially carry the 5Eb chromosome/s and are good candidates for salt tolerant tests in comparison with Iranian modern bread wheat cultivars.

Poor morphological and molecular differentiation in recently diversified lineages is a widespread phenomenon in plants. Phylogenetic relationships within such species complexes are often difficult to resolve because of the low variability in traditional molecular loci. Furthermore, biological phenomena responsible for topological incongruence such as Incomplete Lineage Sorting (ILS) and hybridisation complicate the resolution of phylogenetic relationships among closely related taxa. In this study, we employ a Genotyping-by-sequencing (GBS) approach to disentangle evolutionary relationships within a species complex belonging to the Neotropical orchid genus Cycnoches. This complex includes seven taxa distributed through Central America and the Colombian Chocó, and is nested within a clade estimated to have first diversified in the early Quaternary. Previous phylogenies inferred from few loci failed to provide support for internal relationships within the complex. Our Neighbour-net and coalescent-based analyses inferred from ca. 13,000 GBS loci obtained from 31 individuals belonging to six of the seven traditionally accepted Cycnoches taxa provided a robust phylogeny for this group. The genus Cycnoches includes three main clades that are further supported by morphological traits and geographic distributions. Similarly, a topology reconstructed through maximum likelihood (ML) inference of concatenated GBS loci produced results that are comparable with those reconstructed through coalescence and network-based methods. Our comparative phylogenetic informativeness analyses suggest that the low support evident in the ML phylogeny might be attributed to the abundance of uninformative GBS loci, which can account for up to 50% of the total number of loci recovered. The phylogenomic framework provided here, as well as morphological evidence and geographical patterns, suggest that the six entities previously thought to be different species or subspecies might actually represent only three distinct segregates. We further discuss the limited phylogenetic informativeness found in our GBS approach and its utility to disentangle relationships within recent and rapidly evolving species complexes. Our study is the first to demonstrate the utility of GBS data to reconstruct relationships within young (~2 Ma) Neotropical plant clades, opening new avenues for studies of species complexes that populate the species-rich orchid family UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

Microsatellites (or simple sequence repeats, SSR) are widely used markers in population genetics. Traditionally, genotyping was and still is carried out through recording fragment length. Now, next‐generation sequencing (NGS) makes it easy to obtain also sequence information for the loci of interest. This avoids misinterpretations that otherwise could arise due to size homoplasy. Here, an NGS strategy is described that allows to genotype hundreds of individuals at many custom‐designed SSR loci simultaneously, combining multiplex PCR, barcoding, and Illumina sequencing. We created three different datasets for which alleles were coded according to (a) length of the repetitive region, (b) total fragment length, and (c) sequence identity, in order to evaluate the eventual benefits from having sequence data at hand, not only fragment length data. For each dataset, genetic diversity statistics, as well as F ST and R ST values, were calculated. The number of alleles per locus, as well as observed and expected heterozygosity, was highest in the sequence identity dataset, because of single‐nucleotide polymorphisms and insertions/deletions in the flanking regions of the SSR motif. Size homoplasy was found to be very common, amounting to 44.7%–63.5% (mean over all loci) in the three study species. Thus, the information obtained by next‐generation sequencing offers a better resolution than the traditional way of SSR genotyping and allows for more accurate evolutionary interpretations.

Wild barley forms a two-rowed spike with a brittle rachis whereas domesticated barley has two- or six-rowed spikes with a tough rachis. Like domesticated barley, 'agriocrithon' forms a six-rowed spike; however, the spike is brittle as in wild barley, which makes the origin of agriocrithon obscure. Haplotype analysis of the Six-rowed spike 1 (vrs1) and Non-brittle rachis 1 (btr1) and 2 (btr2) genes was conducted to infer the origin of agriocrithon barley. Some agriocrithon barley accessions (eu-agriocrithon) carried Btr1 and Btr2 haplotypes that are not found in any cultivars, implying that they are directly derived from wild barley through a mutation at the vrs1 locus. Other agriocrithon barley accessions (pseudo-agriocrithon) carried Btr1 or Btr2 from cultivated barley, thus implying that they originated from hybridization between six-rowed landraces carrying btr1Btr2 and Btr1btr2 genotypes followed by recombination to produce Btr1Btr2. All materials we collected from Tibet belong to pseudo-agriocrithon and thus do not support the Tibetan Plateau as being a center of barley domestication. Tracing the evolutionary history of these allelic variants revealed that eu-agriocrithon represents six-rowed barley lineages that were selected by early farmers, once in south-eastern Turkmenistan (vrs1.a1) and again in the eastern part of Uzbekistan (vrs1.a4).

As a result of our taxonomic studies of Astragalus L. sect. Hymenostegis Bunge, we recognize nine new species of this genus from Zanjan Province in northwestern Iran, namely: A. atrokurdicus Maassoumi, F. Ghahrem., Bagheri & Podlech, A. austrotaromensis Maassoumi, F. Ghahrem., Bagheri & Podlech, A. dejectus Maassoumi, F. Ghahrem. & Bagheri, A. mostafa-assadii Bagheri, Maassoumi, F. Ghahrem. & Podlech, A. paralurgiformis F. Ghahrem., Maassoumi & Bagheri, A. pluriflorus F. Ghahrem., Maassoumi, Bagheri & Podlech, A. pseudoparalurges F. Ghahrem., Maassoumi, Bagheri & Podlech, A. sohrevardianus Bagheri, Maassoumi & F. Ghahrem., and A. sublaguriformis Bagheri, Maassoumi & F. Ghahrem., which are described and illustrated here. The new species are also compared with the taxa that are morphologically most similar and presumed to be closely related.

Many conflicting hypotheses regarding the relationships among crops and wild species closely related to wheat (the genera Aegilops, Amblyopyrum, and Triticum) have been postulated. The contribution of hybridization to the evolution of these taxa is intensely discussed. To determine possible causes for this, and provide a phylogeny of the diploid taxa based on genome-wide sequence information, independent data was obtained from genotyping-by-sequencing and a target-enrichment experiment that returned 244 low-copy nuclear loci. The data were analyzed with Bayesian, likelihood and coalescent-based methods. D statistics were used to test if incomplete lineage sorting alone or together with hybridization is the source for incongruent gene trees. Here we present the phylogeny of all diploid species of the wheat wild relatives. We hypothesize that most of the wheat-group species were shaped by a primordial homoploid hybrid speciation event involving the ancestral Triticum and Am. muticum lineages to form all other species but Ae. speltoides. This hybridization event was followed by multiple introgressions affecting all taxa but Triticum. Mostly progenitors of the extant species were involved in these processes, while recent interspecific gene flow seems insignificant. The composite nature of many genomes of wheat group taxa results in complicated patterns of diploid contributions when these lineages are involved in polyploid formation, which is, for example, the case in the tetra-and hexaploid wheats. Our analysis provides phylogenetic relationships and a testable hypothesis for the genome compositions in the basic evolutionary units within the wheat group of Triticeae.

In hyper-arid habitats vegetation tends to be highly patchy with individual plant populations set widely apart from each other. In the Atacama Desert of northern Chile, rainfall is essentially absent, but fog occurring both at the coast and sometimes reaching inland areas supports patches of vegetation in an otherwise barren environment. Tillandsia landbeckii (Bromeliaceae), a epiarenic plant without functional roots, completely depends on fog as source for water, therefore it is found only in fog corridors. Here, we investigate the genetic connectivity within and between populations of T. landbeckii, using genome-wide single-nucleotide-polymorphisms (SNP) obtained through genotyping-by-sequencing (GBS). The 21 sampled populations from the Chilean Atacama Desert are distributed in three geographically ordered south to north clusters, with the southern cluster containing only one population that is genetically very distant from the others. From our study we obtained three genetic groups that corresponded to these three geographical clusters, with the exception of the two populations 16 and 18, where genetic affiliation lies at least in part with the central cluster. Further, our results show uneven distribution of genetic diversity among the populations with highest diversity in the central cluster. We found large amounts of shared heterozygous SNPs as well as negative values for the inbreeding coefficient FIS in the populations of the north and south. They indicate that these populations are strongly affected by clonal reproduction, while the populations in the center are mostly reproducing sexually. We interpret these data as the result of genetic bottlenecks due to founder events involving few dispersing genotypes combined with strong geographical isolation for the northern and southern populations, following stepping stone dispersal of Tillandsia during more climatically favorable episodes.

Balsamocarpon brevifolium C los (Fabaceae), an endangered endemic shrub of the Chilean Atacama Desert, nowadays occurs in fragmented populations, which are exploit since at least 200 years. Understanding its genetic diversity, population structure and distribution patterns are essential for conservation planning and sustainable management. Based on Low-coverage shotgun sequencing (2 × 250 bp) of genomic DNA on the Illumina MiSeq platform we developed microsatellite (SSR) markers. In the nuclear genome we identified 6042 loci with potentially useful microsatellite motifs (83.1% di- and 13.1% tri-nucleotide repeats). Only 2% out of the initially tested 135 tri-nucleotide loci provided reliable amplicons. Back mapping of sequence reads to our initial assembly revealed that the high rate of unsuccessful amplifications was caused by erroneously assembled contigs and/or heterozygosity of the loci at the primer binding sites, highlighting the need of additional control steps such as back mapping especially when dealing with low genomic coverage sequencing. Fifteen markers were finally used to characterize the genetic diversity and variation in 18 populations across the species' natural distribution area. We found in total 183 alleles and inferred moderate genetic diversity from values of HO = 0.611 (STD = 0.018) and HE = 0.557 (STD = 0.015). Genetic variation was higher within populations (91%) than among them (9%). A low but significant correlation between geographical and genetic distances was detected among populations (Mantel test, R2 = 0.16; P = 0.01). Even though distribution barriers might exist due to fragmentation, we found moderate gene flow (Nm = 3.58), which might be explained be seed dispersal by native parrots. S tructure analysis suggests the existence of three genetic clusters, which are not completely distinct from each other. However, we found that habitat discontinuities in the case of B. brevifolium did not yet noticeably impact gene flow and genetic population structure. Taking into account the genetic structure and Ecological Niche prediction under future climate scenarios, in situ conservation efforts for B. brevifolium should focus on populations in the coastal mountains.

Poor morphological and molecular differentiation in recently diversified lineages is a widespread phenomenon in plants. Phylogenetic relationships within such species complexes are often difficult to resolve because of the low variability in traditional molecular loci, as well as various other biological phenomena responsible for topological incongruence such as ILS and hybridization. In this study, we employ a Genotyping-by-sequencing (GBS) approach to disentangle evolutionary relationships within a species complex belonging to the Neotropical orchid genus Cycnoches. The complex includes seven taxa distributed in Central America and the adjacent Chocó biogeographic region, nested within a clade estimated to have first diversified in the early Quaternary. Previous phylogenies inferred from a handful of loci failed to provide support for internal relationships within the complex. Our Neighbor-net and coalescent-based analyses inferred from ca. 13,000 GBS loci obtained from 31 individuals belonging to six of the seven traditionally accepted Cycnoches species provided a robustly supported network. The resulting three main clades are corroborated by morphological traits and geographical distributions. Similarly, Maximum Likelihood (ML) inferences of concatenated GBS-loci produced results comparable with those derived from coalescence and network-based methods, albeit always with poor statistical support. The low support evident in the ML phylogeny might be attributed to the abundance of uninformative GBS loci, which can account for up to 50% of the total number of loci recovered. The phylogenomic framework provided here, as well as morphological evidence and geographical patterns, suggest that the six entities previously thought to be different species might actually represent only three distinct segregates. Our study is the first to demonstrate the utility of GBS data in phylogenomic research of a very young Neotropical plant clade (~2 Ma), and it paves the way for the study of the many other species complexes that populate the species-rich orchid family.

Barley refers to the cereal Hordeum vulgare subsp. vulgare but also more generally to the barley genus Hordeum that, apart from cultivated barley, comprises more than 30 wild grass species distributed in temperate and arid regions of the world. Like wheat and rye, Hordeum belongs to the Triticeae tribe of grasses, most conspicuously characterized by their inflorescence that is a spike instead of the panicle that occurs in most other grasses. The wild progenitor of the cereal is H. vulgare subsp. spontaneum from Southwest Asia. Together with bulbous barley (Hordeum bulbosum), the closest relative of the crop, and wall barley (Hordeum murinum) these species are grouped within subgenus Hordeum, while all other species belong to subgenus Hordeastrum. The crop is easily crossable with its wild progenitor (forming the primary gene pool of barley), while hybrids between cultivated and bulbous barley (secondary gene pool) exhibit low fertility. All other species belong to the tertiary gene pool, resulting in sterile hybrids that can only be established through embryo rescue techniques. However, barley’s tertiary gene pool holds traits for pathogen resistances and adaptations to extreme environmental conditions, which are of high value if they can be transferred into cultivated barley or other cereals. Taxonomic and nomenclatural issues are discussed here in the light of recent findings in molecular systematics and gene function.

Phylogenetic relationships among the taxa of Crocus series Crocus are still unclear, preventing the understanding of species diversity and the evolution of the important spice saffron (Crocus sativus). Therefore, we analyzed sequences of two chloroplast (trnL-trnF, matK-trnK) and three nuclear (TOPO6, ribosomal DNA ETS and ITS) marker regions to infer phylogenetic relationships among all species belonging to series Crocus. Our phylogenetic analyses resolved the relationships among all taxa of the series. Crocus hadriaticus and the former C. pallasii subspecies appeared polyphyletic. The latter deserve elevating the subspecies to species rank, while for C. hadriaticus a detailed study of species boundaries is necessary. Multi-locus and also genome-wide single nucleotide polymorphism data obtained through genotyping-by-sequencing placed C. sativus within C. cartwrightianus with no indication that other Crocus species contributed to the evolution of the triploid. Our analyses thus made an autotriploid origin of C. sativus from C. cartwrightianus very likely.

TOPO6, a nuclear gene-marker region of subunit B of the plant homolog of archaean topoisomerase VI, occurs as single-copy locus in the haploid genome of most plant groups. The gene consists mainly of 19 exons and 18 introns, which provide conserved primer binding sites for PCR amplification in many angiosperm families combined with variable sequence stretches that can be explored in molecular systematics. Here intron/exon structure, sequence diversity, and a set of amplification primers are described to use TOPO6 as single-copy phylogenetic marker region in a wide range of plant taxa, either through PCR amplification or hybridization-based sequence capture.

Allium subgenus Melanocrommyum is taxonomically one of the most complicated groups within Allium and its sectional delimitation has been changed several times. In the present study, the relationships among 136 individuals representing 28 species of the sections Acanthoprason and Asteroprason were surveyed using ISSR (inter simple sequence repeats) markers. Nine ISSR primers generated 322 polymorphic bands (on average 36 bands per primer). In the resulting neighbor joining dendrogram, most conspecific individuals were grouped into clusters, which can be regarded as evidence of the monophyly of most species. Exceptions were the positions of six single samples of A. graveolens, A. zagricum, A. shelkovnikovii, A. subakaka, and A. materculae, which were not grouped with their remaining conspecific individuals. The clusters in dendrograms were significantly correlated with morphological similarities and biogeographical distributions. The lowest molecular similarity (62%) was observed between A. shelkov...

WOS: 000362577700005, As the result of surveying the relevant type specimens, together with macro- and micro-morphological studies, chromosome counting and ITS sequencing, Astragalus trifoliastrum was found to be a species independent of A. laguriformis (with which it has peviously been synonymized). In contrast, A. wanensis, assumed to be a synonym of A. trifoliastrum, indeed appears to be identical with A. trifoliastrum. The diploid chromosome number of 2n = 16 is reported for the first time for A. trifoliastrum.

Breeding of Citrullus spp. for various benefits has continuously raised interest particularly for economically important crops. However, the interspecific variations within the genus have remained obscure in many regards and the multitude of names for taxa and subtaxa eludes Citrullus breeders. In the absence of clear taxonomic differentiation, molecular analysis of phenotypes did not help understand the complexity of this genus until recently. In this study we carried out a phenetic characterization of a world collection of 213 accessions using 22 agro-morphological descriptors in field trials conducted in two locations and during two consecutive years. Multivariate analyses confirmed high morphological variation in Citrullus spp. and highlight C. mucosospermus as a homogenous group separated from other Citrullus species. This differentiation of egusi-type melon will help leverage breeding and conservation purposes as C. lanatus represent very important economic crops in the world. Based on our findings we conclude that our knowledge of the relationships between genetic variations and phenotypic traits and the determinism of morphological variations among and within Citrullus need to be further deepened.

The taxa of Astragalus section Hymenostegis are an important element of mountainous and steppe habitats in Southwest Asia. A phylogenetic hypothesis of sect. Hymenostegis has been obtained from nuclear ribosomal DNA internal transcribed spacer (ITS) and plastid ycf1 sequences of up to 303 individuals from 106 species, including all 89 taxa currently assigned to sect. Hymenostegis, 14 species of other Astragalus sections, and two species of Oxytropis and one Biserrula designated as outgroups. Bayesian phylogenetic inference and parsimony analyses reveal that three species from two other closely related sections group within sect. Hymenostegis, making the section paraphyletic. DNA sequence diversity is generally very low among Hymenostegis taxa, which is consistent with recent diversification of the section. We estimate that diversification in sect. Hymenostegis occurred in the middle to late Pleistocene, with many species arising only during the last one million years, when environmental conditions in the mountain regions of Southwest and Central Asia cycled repeatedly between dry and more humid conditions.

Background Triticeae, the tribe of wheat grasses, harbours the cereals barley, rye and wheat and their wild relatives. Although economically important, relationships within the tribe are still not understood. We analysed the phylogeny of chloroplast lineages among nearly all monogenomic Triticeae taxa and polyploid wheat species aiming at a deeper understanding of the tribe’s evolution. We used on- and off-target reads of a target-enrichment experiment followed by Illumina sequencing. Results The read data was used to assemble the plastid locus ndhF for 194 individuals and the whole chloroplast genome for 183 individuals, representing 53 Triticeae species and 15 genera. We conducted Bayesian and multispecies coalescent analyses to infer relationships and estimate divergence times of the taxa. We present the most comprehensive dated Triticeae chloroplast phylogeny and review previous hypotheses in the framework of our results. Monophyly of Triticeae chloroplasts could not be confirmed, as either Bromus or Psathyrostachys captured a chloroplast from a lineage closely related to a Bromus-Triticeae ancestor. The most recent common ancestor of Triticeae occurred approximately between ten and 19 million years ago. Conclusions The comparison of the chloroplast phylogeny with available nuclear data in several cases revealed incongruences indicating past hybridizations. Recent events of chloroplast capture were detected as individuals grouped apart from con-specific accessions in otherwise monopyhletic groups. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0989-9) contains supplementary material, which is available to authorized users.

Cistanthe longiscapa is an endemic annual herb and characteristic element of the Chilean Atacama Desert. Principal threats are the destruction of its seed deposits by human activities and reduced germination rates due to the decreasing occurrence of precipitation events. To enable population genetic and phylogeographic analyses in this species we performed paired-end shotgun sequencing (2x100 bp) of genomic DNA on the Illumina HiSeq platform and identified microsatellite (SSR) loci in the resulting sequences. From 29 million quality-filtered read pairs we obtained 549,174 contigs (average length 614 bp; N50 = 904). Searching for SSRs revealed 10,336 loci with microsatellite motifs. Initially, we designed primers for 96 loci, which were tested for PCR amplification on three C. longiscapa individuals. Successfully amplifying loci were further tested on eight individuals to screen for length variation in the resulting amplicons, and the alleles were exemplarily sequenced to infer the basis for the observed length variation. Finally we arrived at 26 validated SSR loci for population studies in C. longiscapa, which resulted in 146 bi-allelic SSR markers in our test sample of eight individuals. The genomic sequences were also used to assemble the plastid genome of C. longiscapa, which provides an additional set of maternally inherited genetic markers.

DNA double-strand break (DSB) repair mechanisms differ in their requirements for a homologous repair template and in the accuracy of the result. We aimed to quantify the outcome of repair of a single targeted DSB in somatic cells of young barley (Hordeum vulgare) plants. Amplicon sequencing of three reporter constructs revealed 47 to 58% of reads as repaired via nonhomologous end-joining (NHEJ) with deletions and/or small (1 to 3 bp) insertions. Alternative NHEJ revealed 2 to 5 bp microhomology (15.7% of cases) or new replication-mediated short duplications at sealed breaks. Although deletions outweigh insertions in barley, this bias was less pronounced and deleted sequences were shorter than in Arabidopsis thaliana. Between 17 and 33% of reads likely represent restoration of the original sequence. Depending on the construct, 20 to 33% of reads arose via gene conversion (homologous recombination). Remarkably,1 to8% of reads apparently display synthesis-dependent strand annealing linked with NHEJ, inserting 4 to 61 bp, mostly originating from the surrounding of breakpoints. Positional coincidence of81% of sister chromatid exchanges with target loci is unprecedented for higher eukaryotes and indicates that most repair events for staggered DSBs, at least in barley, involve the sister chromatid and occur during S or G2 phase of the cell cycle.