Stipa is a genus comprising ca. 150 species found in warm temperate regions of the Old World and around 30% of its representatives are of hybrid origin. In this study, using integrative taxonomy ...approach, we tested the hypothesis that hybridization and introgression are the explanations of the morphological intermediacy in species belonging to Stipa sect. Smirnovia, one of the species-rich sections in the mountains of Central Asia. Two novel nothospecies, S. magnifica × S. caucasica subsp. nikolai and S. lingua × S. caucasica subsp. nikolai, were identified based on a combination of morphological characters and SNPs markers. SNPs marker revealed that all S. lingua × S. caucasica samples were F1 hybrids, whereas most of S. magnifica × S. caucasica samples were backcross hybrids. Furthermore, the above mentioned hybrids exhibit transgressive morphological characters to each of their parental species. These findings have implications for understanding the process of hybridization in the genus Stipa, particularly in the sect. Smirnovia. As a taxonomic conclusion, we describe the two new nothospecies S. × muksuensis (from Tajikistan) and S. × ochyrae (from Kyrgyzstan) and present an identification key to species morphologically similar to the taxa mentioned above.
In a period of ongoing climate changes, identifying drivers of overall and endemic species diversity is a key element in constructing new ecological patterns and determining the main goals of ...conservation. Such studies are especially crucial if they concern biodiversity hotspot areas. In this study, we explore patterns and drivers of plant endemism (the proportion of endemic plant species to overall plant species richness; PE) in Tajikistan. We used three groups of climatic measures featuring the contemporary and glacial climates as well as climatic changes since the Last Glacial Maximum in the Pleistocene (LGM). To explore relationships between PE and climatic groups, and the most important climatic variables, we applied the Generalised Additive Model and regression trees method respectively. Glacial climate predicted PE variation the most (74.3%), followed by climate stability (55.4%) and current climate (62.4%). The most important variables represented change in precipitation of driest quarter, glacial mean annual temperature and current annual precipitation. LGM climate and its change to date have the greatest influence on contemporary PE patterns in Tajikistan, revealing the evolutionary dependencies between limited-range plants and past climate. Accordingly, annual temperature and precipitation regimes have been the most crucial drivers of PE since the LGM until today. The study revealed the dependence of the PE on a stabilized water-energy supply. The changing temperature and precipitations regimes during the ongoing climate warming may, therefore, increases the threat to geographically isolated cryophilous plants of Tajikistan, while their escape potential to suitable cold habitats is highly topographically limited.
Display omitted
•Global warming is the main threat to cold-adapted plants in mountain hotspots.•Past climate affects demographic history and current distribution of mountain plants.•Geographic ...vicariants variously respond to forecasted climate changes.•S. gracilis and S. zeravshanica are neoendemics originated in the late Pleistocene.•Predicted climate warming threatens rocky vegetation in the western Pamir-Alai Mts.
Understanding species distribution, genetic diversification and evolutionary history is extremely important for mountainous regions with a high diversity of endemic species, which are particularly sensitive to climate change. In this study, we use environmental and molecular data obtained from genome-wide analyses to infer the genetic variability, demographic processes, and response of the cold-adapted, endemic geographical-vicariants Stipa gracilis (distributed in the Tian Shan Mts) and S. zeravshanica (distributed in the western Pamir-Alai Mts) to Quaternary climatic oscillations in a Central Asian mountain biodiversity hotspot. Genomic-based reconstructions of demographic history indicate that the examined endemics presented larger effective population sizes during the Last Glacial Maximum (LGM) period and experienced parallel demographic declines afterward. The results of fastSTRUCTURE analysis revealed three genetic clusters within S. gracilis populations and two within S. zeravshanica. The past distribution models reveals the glacial connectivity of both species, resulting in the detection of an admixture of S. zeravshanica genes in the specimens from the westernmost ‘Alaian’ population of S. gracilis. Although the occurrence of both species is closely associated with calcareous rocks, the differences in the ranges of the species distributions depend mostly on climatic factors, especially temperature and precipitation. The wider realized ecological niche of S. gracilis allows it to better adapt to global warming and potentially extend its range in the future, while S. zeravshanica, with its narrower niche, is more susceptible to environmental changes and potentially at risk of extinction. The findings will contribute to a better understanding of the factors shaping the distribution and genetic differentiation of mountain endemic species and provide a theoretical basis for their conservation by identifying areas sensitive to climate change in biodiversity hotspots.
Together with other elevated areas, the Mountains of Central Asia are significantly threatened by ongoing climate change. The presence of refuges during the glaciations makes the region extremely ...rich in species, especially endemic ones. However, the limited potential for colonisation of other habitats makes rocky-related species with 'island-like' distribution, particularly vulnerable to climate change. To understand the processes underlying species response to climate warming, we assessed differences in ecological niches and phylogenetic relationship of two geographically disjunctive alpine species belonging to the genus Sergia. The taxa are considered Tertiary relicts, endemic to the Tian Shan and Pamir-Alai Mountains. To illustrate range dynamics and differences in occupied niches of Sergia species, we used Ecological Niche Modelling of current and future distribution. Whereas, to reconstruct the phylogenetic relationship within and between Sergia and other related Campanulaceae species from the region we used molecular data (ITS, cpDNA, DArTseq-derived SNPs).
The results reveal that the genus Sergia is a polyphyletic group, and its representatives differ geographically, ecologically and genetically. Both S. regelii and S. sewerzowii constitute a common clade with Asyneuma group, however, S. sewerzowii is more closely related to Campanula alberti (a species that has never previously been considered closely related to the genus Asyneuma or Sergia) than to S. regelii. Sergia sewerzowii is adapted to lower elevations with higher temperatures, while S. regelii prefers higher elevations with lower temperatures. The future distribution models demonstrate a dramatic loss of S. regelii range with a shift to suitable habitats in higher elevations, while the potential range of S. sewerzowii increases and shifts to the north.
This study shows that S. regelii and S. sewerzowii have a long and independent evolution history. Sergia regelii and S. sewerzowii significantly differ in realised niches. These differences are mirrored in the response of the studied endemics to future climate warming. As suitable habitats shrink, rapid changes in distribution can lead to species' range loss, which is also directly related to declines in genetic variability. The outcomes of this paper will help to more precisely assess the impact of climate changes on rocky-related plant species found in this world's biodiversity hotspot.
Herbaria constitute a form of documentation, store and secure comparative material, as well as constitute an extra original gene bank. They are an invaluable database among others for the biological, ...ethnobotanical and agricultural sciences. The digitization of herbarium collections significantly facilitates access to archival materials; however, searching them is still time-consuming. Therefore, our work aims to analyze the herbarium collection of 8801 sheets for specimens representing the economically important family Amaranthaceae (Chenopodiaceae-Amaranthaceae clade) deposited the oldest herbarium in Poland, the herbarium of the Jagiellonian University (KRA). These specimens have been collected from almost all the continents in dozens of countries for over 200 years. The analyses conducted, including the taxonomic coverage, geographical characteristics and origin, temporal coverage and utility importance of representative species, present the discussed resources in a more accessible way and may become a more attractive form for scientists potentially interested in more advanced research work.
Hybridisation in the wild between closely related species is a common mechanism of speciation in the plant kingdom and, in particular, in the grass family. Here we explore the potential for natural ...hybridisation in Stipa (one of the largest genera in Poaceae) between genetically distant species at their distribution edges in Mountains of Central Asia using integrative taxonomy. Our research highlights the applicability of classical morphological and genome reduction approaches in studies on wild plant species. The obtained results revealed a new nothospecies, Stipa × lazkovii, which exhibits intermediate characters to S. krylovii and S. bungeana. A high-density DArTseq assay disclosed that S. × lazkovii is an F1 hybrid, and established that the plastid and mitochondrial DNA was inherited from S. bungeana. In addition, molecular markers detected a hybridisation event between morphologically and genetically distant species S. bungeana and probably S. glareosa. Moreover, our findings demonstrated an uncertainty on the taxonomic status of S. bungeana that currently belongs to the section Leiostipa, but it is genetically closer to S. breviflora from the section Barbatae. Finally, we noticed a discrepancy between the current molecular data with the previous findings on S. capillata and S. sareptana.
Abstract
In the last decades, biological invasions become the main driver of biodiversity loss. The changes can be noticed not only in the above-ground diversity but also in the underground, ...including seed banks of native vegetation. In this study, we focus on
Rudbeckia laciniata
, a species introduced to many European and Asian countries, to characterize its soil seed bank as well as to answer the question, how the species influenced soil seed banks of meadow plant communities in two types of habitats (fresh and wet), where traditional mowing was abandoned. Within the habitats, we conducted our study on a three-step scale of invasion, from full invasion, through the transition zone to the control zone, where no invasion of the species has been observed so far. The majority of the
R. laciniata
seeds were located in the surface layer of soil. We detected, that 47% (in fresh meadow) and 56% (wet meadow) of recorded species occurred only in a soil seed bank, and were absent in aboveground vegetation. Emergence of native plants from the soil seed bank is low due to rapid shading of the soil surface by
R. laciniata
seedlings. However, a short-term seed bank of the species gives hope that returning to regular mowing brings the desired results in its the elimination from vegetation, in a fairly short time.
Hybridization is one of the key processes shaping lineage diversification, particularly in regions that experienced strong climate oscillations. The alpine biome with its rich history of ...glacial-interglacial cycles and complex patterns of species distribution shifts offers an excellent system to investigate the impact of gene flow on population dynamics and speciation, important issues for evolutionary biology and biodiversity conservation. In this study, we combined genomic data (DArTseq), chloroplast markers, and morphology to examine phylogenetic relationships and the permeability of species boundaries and their evolutionary outcomes among the alpine extremophilic species of
(Poaceae) in the Pamir Mountains, a part of the Mountains of Central Asia biodiversity hotspot. We determined the occurrence of interspecific hybrids between
and
, which demonstrated almost symmetric ancestry from their parental species and did not show signals of introgression. According to our integrative revision, the natural hybrids between
and
should be classified as
×
(pro species). Using approximate Bayesian computation for population history inference, we uncovered that
hybridized with
independently in multiple localities over the Holocene. Hybrids inherited the fine-scale genetic structure from their parental species, which developed these patterns earlier, during the Late Pleistocene. Hybridization had different consequences for the involved parental lineages, likely playing an important role in a continuing decline of
in the Pamir Mountains over the Holocene. Our results show that
should be considered a critically endangered species in the Pamir Mountains and could also be retreating across its entire range of distribution in High Mountain Asia. Using a comparative phylogeographic framework, we revealed the risk of extinction of a cold-adapted alpine species in a global biodiversity hotspot. This study highlights that genomics could unravel diversity trends under climate change and provides valuable evidence for conservation management.
Central Pamir-Alai, which is located almost entirely within the area of Tajikistan, is one of the world hotspots of biodiversity, harbouring ca. 4,300 species and 1,400 endemic plants. The first ...application of the IUCN Red List criteria reveals that among all native species occurring in Tajikistan 1,627 taxa (38.11%) are threatened, including 23 extinct (0.54%), 271 (6.34%) critically endangered (CR), 717 (16.79%) endangered (EN) and 639 (14.96%) vulnerable (VU). Globally, 20 taxa are extinct, 711 (16.65%) threatened, including 144 (3.37%) critically endangered, 322 (7.54%) endangered and 245 (5.73%) vulnerable. As we found positive correlation between human density and the number of threatened species, we suspect this indirect factor responsible for the species diversity decline. Extinct or threatened taxa have short blooming periods in spring or early summer, have limited geographical range and inhabit mainly valley bottoms at lower altitudes. Threatened taxa occupy extremely dry or wet habitats, such as deserts, semi-deserts, water reservoirs and fens. The group of threatened plants consists mostly of Central Asian, Indo-Indochinese and Arctic species. Ornamental plants have a higher extinction risk than other plants, but species collected for medicinal reasons and used for forage or food reveal lower retreatment rate. Our assessment fills a gap for important plant area and provides the data for raising the effectiveness of plant diversity conservation.
Abstract
The Eurasian plant
Stipa capillata
is the most widespread species within feather grasses
.
Many taxa of the genus are dominants in steppe plant communities and can be used for their ...classification and in studies related to climate change. Moreover, some species are of economic importance mainly as fodder plants and can be used for soil remediation processes. Although large-scale molecular data has begun to appear, there is still no complete or draft genome for any
Stipa
species. Thus, here we present a single-molecule long-read sequencing dataset generated using the Pacific Biosciences Sequel System. A draft genome of about 1004 Mb was obtained with a contig N50 length of 351 kb. Importantly, here we report 81,224 annotated protein-coding genes, present 77,614 perfect and 58 unique imperfect SSRs, reveal the putative allopolyploid nature of
S. capillata
, investigate the evolutionary history of the genus, demonstrate structural heteroplasmy of the chloroplast genome and announce for the first time the mitochondrial genome in
Stipa.
The assembled nuclear, mitochondrial and chloroplast genomes provide a significant source of genetic data for further works on phylogeny, hybridisation and population studies within
Stipa
and the grass family Poaceae.
PDF
