Species Stipa Research Articles

IPPRAS Cryobank for the Conservation of Orthodox Seeds of Rare, Endangered, Medicinal, and Ornamental Plant Species-Current Research.

Plant cryobanks play a significant role in modern science and breeding. They contribute to the recovery of lost species, the emergence of new plant varieties, and help preserve and explore the diversity of the plant world. The IPPRAS Cryobank collection is constantly supplemented with new samples, while, at the same time, the stored samples are being monitored. In order to test seed germination, seeds of Allium and Veratrum species were thawed. Rare Allium species seeds, such as A. nutans, A. schoenoprasum, and A. victorialis were stored in liquid nitrogen for 17, 19, and 30 years, respectively. Long-term cryopreservation decreased germination rates for A. nutans from 96.55 to 50.00%, for A. schoenoprasum from 72.00 to 62.75%, and for A. victorialis from 90.00 to 83.05%. Seeds of a rare medicinal species, Veratrum lobelianum, were stored in liquid nitrogen for 18 years; the seed germination rate during this storage period has been significantly decreased from 75.00 to 14.81%. V. nigrum seeds were also collected and frozen in liquid nitrogen for 3 days. Short-term cryopreservation did not result in a statistically significant change in germination rates (from 79.71 to 82.69%). The seeds of an endangered ornamental species, Cypripedium calceolus, were collected and kept frozen for 3 days. After cryopreservation, the seeds were planted on three different media, as follows: ½ MS, MS with 10% coconut milk, and BM1. On ½ MS medium, 24.98% seeds formed protocorms, while on MS medium with 10% coconut milk, this number was 10.02%, and on BM1 medium, it was 15.02%, respectively; however, after 2.5 months, all of the protocorms died. Thus, it appears that the existing protocol for seed cryopreservation of C. calceolus needs further improvement. The size, weight, and free water content (WC) of six previously cryopreserved Stipa species and three Allium species were measured. For all the Allium and Stipa species studied, we found no correlation between seed size, WC, and cryotolerance. We also found no correlation between the life form, which reflects the water requirement of the species, and cryotolerance.

Predicted changes in distribution and grazing value of Stipa-based plant communities across the Eurasian steppe

The Eurasian steppe is one of the world's largest continuous areas of grassland and has an important role in supporting livestock grazing, the most ubiquitous land use on Earth. However, the Eurasian steppe is under threat, from irrational grazing utilization, climate change, and resource exploitation. We used an ensemble modeling approach to predict the current and future distribution of Stipa-dominated plant communities in three important steppe subregions; the Tibetan Alpine, Central Asian, and Black Sea-Kazakhstan subregions. We combined this with an assessment of the grazing value of 22 Stipa species, the dominant grassland species in the area, to predict how grazing value might change under future climate change predictions. We found that the effects of changing climates on grazing values differed across the three subregions. Grazing values increased in the Tibetan alpine steppe and to a lesser extent in Central Asia, but there were few changes in the Black Sea-Kazakhstan subregion. The response of different species to changing climates varied with environmental variables. Finally, our trait-based assessment of Stipa species revealed variations in grazing value, and this had major effects on the overall grazing value of the region. Our results reinforce the importance of trait-based characteristics of steppe plant species, how these traits affect grazing value, and how grazing values will change across different areas of the Eurasian steppe. Our work provides valuable insights into how different species will respond to changing climates and grazing, with important implications for sustainable management of different areas of the vast Eurasian steppe ecosystem.

SUSTAINABLE CONSTRUCTION TECHNIQUES WITH BAMBOO AND ICHU STRAW AS A CONTRIBUTION TO ANDEAN ARCHITECTURAL IDENTITY

The present study evaluates the contribution of the use of sustainable construction techniques with plant fibers: bamboo and ichu straw in the architectural identity of Tarma, Junín region. For which the research method considers two phases, in the first, sustainable construction techniques are evaluated and developed, taking into account two dimensions: "the use of local bamboo and ichu straw", with the selection of three species of bamboo from the environment: a native of the genus Chusquea, and two exotics of the genera Guadua and Phillostachys, and the species Stipa ichu; and the “design and application”, with the construction of three architectural models, using the four species, in which the local population participated by adapting traditional weaving techniques with ichu straw. In the second phase, a semi-structured survey is prepared to collect data related to the identity of the local people regarding their territory and the architecture, and the perception and impact generated by the three models. Among the results of the first and second phase, the possibilities of using bamboo as a construction material according to the species, the adaptability and fusion of traditional techniques in contemporary designs, the identification of the local’s people with the proposed models, as well as verification of sustainable guidelines applied in design and construction.

Spatial variations of fungal community assembly and soil enzyme activity in rhizosphere of zonal Stipa species in inner Mongolia grassland

Rhizosphere soil fungal and enzyme activities affect the nutrient cycling of terrestrial ecosystems, and rhizosphere fungi are also important participants in the ecological process of vegetation succession, responding to changes in plant communities. Stipa is an excellent forage grass with important ecological and economic value, and has the spatial distribution pattern of floristic geographical substitution. In order to systematically investigate the synergistic response strategies of fungal communities and enzyme activities in the rhizosphere under the vegetation succession. Here we explored the turnover and assembly mechanisms of Stipa rhizosphere fungal communities and the spatial variation of metabolic activity under the succession of seven Stipa communities in northern China grassland under large scale gradients. The results indicated that the composition, abundance and diversity of fungal communities and microbial enzyme activities in rhizosphere soil differed among different Stipa species and were strikingly varied along the Stipa community changes over the geographic gradient. As the geographical distribution of Stipa community changed from east to west in grassland transect, Mortierellomycetes tended to be gradually replaced by Dothideomycetes. The null models showed that the rhizosphere fungal communities were governed primarily by the dispersal limitation of stochastic assembly processes, which showed decreased relative importance from S. grandis to S. gobica. Moreover, the MAT and MAP were the most important factors influencing the changes in the fungal community (richness, β-diversity and composition) and fungal community assembly, while SC and NP also mediated fungal community assembly processes. These findings deepen our understanding of the responses of the microbial functions and fungal community assembly processes in the rhizosphere to vegetation succession.

Evaluation of Seed Germination of Six Rare Stipa Species following Low Temperature Stress (Cryopreservation).

Cryopreservation is one way to preserve rare, endangered species. However, during the cryopreservation process, plant cells undergo considerable stress, which may lead to cell death. In our work, orthodox Stipa seeds of six rare species were cryopreserved: S. sareptana, S. ucrainica, S. tirsa, S. dasyphylla, S. adoxa, and S. pulcherríma. Short-term cryopreservation (14 days) stimulated germination of all Stipa species studied. Prolonged cryopreservation (70 days and more) decreased the germination of all Stipa seeds except S. sareptana. The decrease in germination progressed over time as a result of the cumulative stress of cryopreservation rather than the initial stress. To stimulate germination, seeds were stratified and treated with GA3, KNO3, NaOH, and H2O2. After four years of seed cryopreservation, it was possible to obtain seedlings of all the Stipa species studied with 30 days of stratification and 180 days of germination. After five years of cryopreservation and seed treatment with 30% NaOH for one hour, the best germination was obtained in S. adoxa and S. pulcherrima. After treatment with 5% H2O2 for 20 min, the best germination was obtained in S. sareptana, S. ucrainica, and S. dasyphylla. S. sareptana seeds germinated in all the aforementioned experiments. S. sareptana has a non-deep physiological dormancy and is the most widespread and drought-tolerant Stipa species studied. The best habitat adaptation and stress tolerance correlated with this species'cryotolerance. S. sareptana was recommended for further cryopreservation, while storage protocols for the other Stipa species studied need further improvements.

Elucidation of the evolutionary history of Stipa in China using comparative transcriptomic analysis.

Phylogenetic analysis provides crucial insights into the evolutionary relationships and diversification patterns within specific taxonomic groups. In this study, we aimed to identify the phylogenetic relationships and explore the evolutionary history of Stipa using transcriptomic data. Samples of 12 Stipa species were collected from the Qinghai-Tibet Plateau and Mongolian Plateau, where they are widely distributed, and transcriptome sequencing was performed using their fresh spikelet tissues. Using bidirectional best BLAST analysis, we identified two sets of one-to-one orthologous genes shared between Brachypodium distachyon and the 12 Stipa species (9397 and 2300 sequences, respectively), as well as 62 single-copy orthologous genes. Concatenation methods were used to construct a robust phylogenetic tree for Stipa, and molecular dating was used to estimate divergence times. Our results indicated that Stipa originated during the Pliocene. In approximately 0.8 million years, it diverged into two major clades each consisting of native species from the Mongolian Plateau and the Qinghai-Tibet Plateau, respectively. The evolution of Stipa was closely associated with the development of northern grassland landscapes. Important external factors such as global cooling during the Pleistocene, changes in monsoonal circulation, and tectonic movements contributed to the diversification of Stipa. This study provided a highly supported phylogenetic framework for understanding the evolution of the Stipa genus in China and insights into its diversification patterns.

Changes of root AMF community structure and colonization levels under distribution pattern of geographical substitute for four Stipa species in arid steppe

The establishment of symbiotic relationship between arbuscular mycorrhizal fungi (AMF) and roots is a mutually beneficial process and plays an important role in plant succession in ecosystems. However, there is less understanding of information about the AMF community in roots under vegetation succession on a large regional scale, especially the spatial variation in the AMF community and its potential ecological functions. Here, we elucidated the spatial variations in root AMF community structure and root colonization along a distribution pattern of four zonal Stipa species in arid and semiarid grassland systems and explored key factors regulating AMF structure and mycorrhizal symbiotic interactions. Four Stipa species established a symbiosis with AMF, and annual mean temperature (MAT) and soil fertility were the main positive and negative driving factors of AM colonization, respectively. The Chao richness and Shannon diversity of AMF community in the root system of Stipa species tended to increase firstly from S. baicalensis to S. grandis and then decreased from S. grandis to S. breviflora. While evenness of root AMF and root colonization showed a trend of increasing from S. baicalensis to S. breviflora, and biodiversity was principally affected by soil total phosphorus (TP), organic phosphorus (Po) and MAT. It is emphasized that Stipa species have certain dependence on AMF, especially in a warming environment, and the root AMF community structure among the four Stipa taxa was different. Additionally, the composition and spatial distribution of root AMF in host plants varied with MAT, annual mean precipitation (MAP), TP and host plant species. These results will broaden our understanding of the relationship between plant and AMF communities and their ecological role, and provide basic information for the application of AMF in the conservation and rehabilitation of forage plants in degraded semiarid grasslands.

Plant Community Transformations in Desert Rangeland Ecosystems – Evidence from the North-Western Caspian Lowland

Abstract—The article presents the results of long-term monitoring of successions, and the production dynamics in desert rangeland phytocoenoses over an 8-year period (2014–2021). It shows the current state of vegetative cover of the Chernozemelskaya sandy plain (north-west of the Caspian lowland, Republic of Kalmykia) following forest reclamation of fine-grained sands, carried out in the 1970s–1990s. The centers of soil deflation (aeolian erosion) differed by the degree of soil and vegetative cover transformation and the methods of the reclamation of open sands. Currently, a secondary vegetative cover has been formed on the previously identified deflation patches. The expansion and evolution of the current species composition suggests the development of secondary succession. The features of the synusial structure of desert phytocenoses reflect the state of plant communities. The relationship of the productivity of model pastures (shrub Callygonum aphyllum, subshrub Krascheninnikovia ceratoides, herbaceous species Stipa lessingiana, Artemisia lerchiana, Alyssum deserforum, Bromus tectorum, Carex stenophylla, Koeleria macrantha, Poa bulbosa) with precipitation in warm and cold periods of the growing season is analyzed. Under changing temporal and spatial climate dynamics, the successional processes are greatly influenced by wildfires and anthropogenic impact. It has been established that secondary successions under heavy transformation of the agro-pasture landscape develop more slowly. Thus, the natural and landscape environment of the current deflation centres in the rangelands of the North-Western Caspian region is an important factor determining the direction of succession.

The Distribution and Turnover of Bacterial Communities in the Root Zone of Seven Stipa Species Across an Arid and Semi-arid Steppe.

The bacterial communities of the root-zone soil are capable of regulating vital biogeochemical cycles and the succession of plant growth. Stipa as grassland constructive species is restricted by the difference features of east–west humidity and north–south heat, which shows the population substituting distribution. The distribution, turnover, and potential driving factors and ecological significance of the root-zone bacterial community along broad spatial gradients of Stipa taxa transition remain unclear. This paper investigated seven Stipa species root-zone soils based on high-throughput sequencing combined with the measurements of multiple environmental parameters in arid and semi-arid steppe. The communities of soil bacteria in root zone had considerable turnover, and some regular variations in structure along the Stipa taxa transition are largely determined by climatic factors, vegetation coverage, and pH at a regional scale. Bacterial communities had a clear Stipa population specificity, but they were more strongly affected by the main annual precipitation, which resulted in a biogeographical distribution pattern along precipitation gradient, among which Actinobacteria, Acidobacteria, Proteobacteria, and Chloroflexi were the phyla that were most abundant. During the transformation of Stipa taxa from east to west, the trend of diversity shown by bacterial community in the root zone decreased first, and then increased sharply at S. breviflora, which was followed by continuous decreasing toward northwest afterwards. However, the richness and evenness showed an opposite trend, and α diversity had close association with altitude and pH. There would be specific and different bacterial taxa interactions in different Stipa species, in which S. krylovii had the simplest and most stable interaction network with the strongest resistance to the environment and S. breviflora had most complex and erratic. Moreover, the bacterial community was mainly affected by dispersal limitation at a certain period. These results are conducive to the prediction of sustainable ecosystem services and protection of microbial resources in a semi-arid grassland ecosystem.

Classification of desert steppe species based on unmanned aerial vehicle hyperspectral remote sensing and continuum removal vegetation indices

Grassland species composition is a key indicator for assessing grassland ecological health. In order to obtain the distribution of species in the desert steppe of Gegen tara, Inner Mongolia, China, we used a new hyperspectral imaging system based on an unmanned aerial vehicle to acquire images. Through spectral transformation, the spectral difference of species was increased. The classification features of desert steppe species were constructed by spectral transformation vegetation indices. The maximum interclass variance was used to compare the reflectance vegetation index, the first order transformation differential vegetation index, the logarithm transformation vegetation index and the continuum removal transformation vegetation index, to select the classification features and to calculate the classification threshold. The classification decision tree model constructed by continuum removal transformation normalized differential vegetation index and continuum removal transformation difference vegetation index has the best effect on desert steppe species classification, and the overall classification accuracy and Kappa coefficient are 87% and 0.8. The classification and identification of keystone species Stipa breviflora Griseb., Artemisia frigida Willd., and Salsola collina Pall. in the desert steppe were realized by this new method. Our study will have a positive effect on the understanding of the evolutionary law of grassland ecosystems, and provide quantitative indicators for grassland ecological management.

Effects of nitrogen addition on plant-soil-microbe stoichiometry characteristics of different functional group species in Bothriochloa ischemum community

Nitrogen (N) deposition, the source of N input into terrestrial ecosystems, is exhibiting an increasingly serious impact on the biogeochemical cycle and functional stability of ecosystems. Grasslands are an important component of terrestrial ecosystems and play a key role in maintaining terrestrial ecosystem balance. Therefore, it is critical to understand the effects of nitrogen addition on grassland ecosystems. We conducted gradient N addition experiments (0, 3, 6, and 9 g N m−2 y−1) for three years in grassland communities with similar site conditions. We utilized four typical herbaceous plants, including the dominant species Bothriochloa ischemum (B. ischemum) and companion species Stipa bungeana (S. bungeana), Artemisia gmelinii (A. gmelinii), and Cleistogenes squarrosa (C. squarrosa), to explore how different plant-soil-microbe systems respond to N addition. Stoichiometric homeostasis analysis demonstrated that both plants and microbes were strictly homeostatic. However, the companion species were found to be more susceptible to P dominant species. Furthermore, aggravated overlap in stoichiometric niches between plant species were observed at the N6 and N9 levels. Vector analysis indicated that the vector angle was >45° regardless of plant species and N levels, suggesting that there was a strong P limitation in the rhizosphere microbial community. Variation partitioning analysis revealed that the Composite roots exhibited a greater effect (explaining 34.7% of the variation) on the rhizosphere microbes than on the Gramineae, indicating that there may be more intense nutrient competition in its rhizosphere. In general, the effects of N addition on species were different across functional groups, with asignificant positive effect on the Gramineae (B. ischemum, S. bungeana,and C. squarrosa) and a significant negative effect on the Compositae (A. gmelinii), which should be fully considered in the future ecological management and restoration.

The first draft genome of feather grasses using SMRT sequencing and its implications in molecular studies of Stipa

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.

Distribution of species of the genus Stipa in Ukraine according to phytosociological databases

The paper presents the current distribution of species of the genus Stipa in Ukraine based on the data from phytosociological databases. The main objectives were to produce maps of distribution and to determine the affinity of Stipa species to EUNIS habitat classification units.We succeeded in selecting the relevés with the participation of 16 out of 27 species of the genus Stipa recognized as a species in the “Nomenclature checklist of higher vascular plants of Ukraine”. A total of 4888 relevés with the presence of Stipa were found. Stipa capillata has the most significant presence in the data set among other species of the genus. It was found in 38.1 % of relevés. This species occupies second place in the analyzed data set by the Percentage Frequency and third place by Average Non-Zero Cover. According to the analysis of the distribution maps, it was established that S. capillata is a widespread species in the Forest-Steppe and the Steppe zones of Ukraine. Stipa lessingiana also has a significant distribution but is limited mainly to the Steppe zone. Both S. borysthenica and S. tirsa are significantly less present in the databases than reported in the literature, particularly in the Red Book of Ukraine and Green Book of Ukraine. Other species of the genus have limited distribution. Analysis of the habitat affinity of Stipa species showed that they occur in ten types of grassland habitats of the third level of the hierarchy according to the new version of the EUNIS classification. The vast majority of species have an ecological optimum in R1B – Continental dry grassland (true steppe). Stipa capillata has the widest amplitude in different habitat types. Also, a wide range of habitat types is characteristic for S. pulcherrima, S. lessingiana, S. pennata, and S. ucrainica. Species that are poorly represented in the dataset (S. zalesskii, S. transcarpatica, S. adoxa, S. asperella, and S. dasyphylla) occur in a few or only one habitat type.Hence, our study shows that the vast majority of Stipa species in Ukraine are rare and need protection at the national level. However, the presence of S. capillata in the sample was very high. It was found in almost all types of dry grassland habitats, as well as in petrophytic, shrub, and even anthropogenic habitats. This is evidence of the high adaptability of the species and its wide ecological and coenotic amplitude. Our study results confirm the idea that S. capillata does not meet the criteria for inclusion to the national protection lists. It also suggests excluding this species from the Red Book of Ukraine, in case if the national legislation will regulate the protection of biodiversity at the superorganism level.

Comparison of Thermal and Hydrotime Requirements for Seed Germination of Seven Stipa Species From Cool and Warm Habitats.

Temperature and water potential are two important environmental factors influencing germination and subsequent seedling establishment. Seed germination requirements vary with species and with the environment in which the seeds are produced. Stipa species dominate large areas of the Eurasian zonal vegetation, but comparisons of germination requirements between Stipa species from different habitats is limited. We investigated the effects of temperature and water potential on seed germination of S. grandis, S. purpurea, and S. penicillata from habitats with low temperatures and relatively abundant rainfall (cool habitats) and S. glareosa, S. breviflora, S. gobiea, and S. bungeana from habitats with relatively high temperatures and low amount of rainfall (warm habitats). Seeds of species from cool habitats had a higher base (T b), optimal (T o), and maximum (T c) temperature than those of species from warm habitats, except for the base temperature of S. purpurea. Response of six tested Stipa species to water potential differed among species but not between habitats. Median water potential for germination was lowest for S. bungeana, S. penicillata, and S. gobiea. There was a negative correlation between hydrotime constant (θ H) and base water potential for 50% of the seeds of all species to germinate (ψ b(50)). Germination time of seven Stipa species in response to temperature and water was well predicted by thermal time and hydrotime models. Results of the present study on germination of these seven species of Stipa may provide useful suggestions for grassland restoration in different habitats.

Five-year study on the effects of warming and plant litter quality on litter decomposition rate in a Tibetan alpine grassland

The decomposition of plant litter is a key link in global C budgets and provides strong feedback to changes in climate and biogeochemical cycles. However, the combined effects of global warming and plant litter quality on the rate of plant litter decomposition and nutrient dynamics in alpine ecosystems are still poorly understood. We conducted a warming experiment to investigate the effects of litter quality and temperature on decomposition rates and variations in nutrients of four common herbaceous plants (low-quality litter species Stipa purpurea and Carex moorcroftii and high-quality litter species Astragalus confertus and Leontopodium nanum) during 2011–2016. During the initial stages of decomposition, warming had no significant effect on the mass loss of plant litter for low-quality litter species, but in the later stages of decomposition, it had a negative effect on the mass loss across all species (P < 0.05). Litter quality was the best predictor of N and P release/immobilisation during the decomposition of aboveground plant litter. Low-quality litter had the highest immobilisation of N at about 80% of the initial remaining mass; nutrients were then released in the following stages of decomposition. However, the fraction of initial P decreased with the mass remaining during the initial and later phases of decomposition, but a short period of P immobilisation occurred in the middle phase of decomposition. For high-quality litter, the fraction of initial N and P decreased with the mass remaining during the whole decomposition process. Warming had a marginal influence on the N and P dynamics throughout the decomposition process. Our study showed that the decay of plant litter was strongly suppressed by warming climate and that the N and P dynamics on the investigated Tibetan grassland were mainly regulated by litter quality, providing valuable insights into the biogeochemical cycles of nutrients in alpine ecosystems.

A Synopsis of the Genus Stipa (Poaceae) in Middle Asia, Including a Key to Species Identification, an Annotated Checklist, and Phytogeographic Analyses

The genus Stipa L. comprises over 150 species, all native to the Old World, where they grow in warm temperate regions throughout Europe, Asia, and North Africa. It is one of the largest genera in the family Poaceae in Middle Asia, where one of its diversity hotspots is located. However, identification of Middle Asian Stipa species is difficult because of the lack of new, comprehensive taxonomic studies including all of the species recorded in the region. We present a critical review of the Mid-Asian representatives of Stipa, together with an identification key and taxonomic listing. We relied on both published and unpublished information for the taxa involved, many of which are poorly known. For each taxon, we present a taxonomic and nomenclatural overview, habitat preferences, distribution, altitudinal range, and additional notes as deemed appropriate. We describe four new nothospecies: S. ×balkanabatica M. Nobis &amp; P. D. Gudkova, S. ×dzungarica M. Nobis, S. ×pseudomacroglossa M. Nobis, S. ×subdrobovii M. Nobis &amp; A. Nowak, one subspecies S. caucasica Schmalh. subsp. nikolai M. Nobis, A. Nobis &amp; A. Nowak, and eight varieties: S. araxensis Grossh. var. mikojanovica M. Nobis, S. caucasica var. fanica M. Nobis, P. D. Gudkova &amp; A. Nowak, S. drobovii (Tzvelev) Czerep. var. jarmica M. Nobis, S. drobovii var. persicorum M. Nobis, S. glareosa P. A. Smirn. var. nemegetica M. Nobis, S. kirghisorum P. A. Smirn. var. balkhashensis M. Nobis &amp; P. D. Gudkova, S. richteriana Kar. &amp; Kir. var. hirtifolia M. Nobis &amp; A. Nowak, and S. ×subdrobovii var. pubescens M. Nobis &amp; A. Nowak. Additionally, 12 new combinations, Achnatherum haussknechtii (Boiss.) M. Nobis, A. mandavillei (Freitag) M. Nobis, A. parviflorum (Desf.) M. Nobis, Neotrinia chitralensis (Bor) M. Nobis, S. badachschanica Roshev. var. pamirica (Roshev.) M. Nobis, S. borysthenica Klokov ex Prokudin var. anomala (P. A. Smirn.) M. Nobis, S. holosericea Trin. var. transcaucasica (Grossh.) M. Nobis, S. kirghisorum P. A. Smirn. var. ikonnikovii (Tzvelev) M. Nobis, S. macroglossa P. A. Smirn. var. kazachstanica (Kotuchov) M. Nobis, S. macroglossa var. kungeica (Golosk.) M. Nobis, S. richteriana var. jagnobica (Ovcz. &amp; Czukav.) M. Nobis &amp; A. Nowak, and S. zalesskii Wilensky var. turcomanica (P. A. Smirn.) M. Nobis are proposed, and the lectotypes for 14 taxa (S. arabica Trin. &amp; Rupr., S. bungeana Trin. ex Bunge, S. caspia K. Koch, S. ×consanguinea Trin. &amp; Rupr., S. effusa Mez, S. ×heptapotamica Golosk., S. jacquemontii Jaub. &amp; Spach., S. kungeica Golosk., S. margelanica P. A. Smirn., S. richteriana, S. rubentiformis P. A. Smirn., S. sareptana A. K. Becker, S. tibetica Mez, and Timouria saposhnikovii Roshev.) are designated. In Middle Asia the genus Stipa comprises 98 taxa, including 72 species, four subspecies, and 22 varieties. Of the 72 species of feather grasses, 23 are of hybrid origin (nothospecies). In Middle Asia, feather grasses can be found at elevations from (0 to)300 to 4500(to 5000) m, but most are montane species. The greatest species richness is observed at altitudes between 1000 and 2500 m. Nineteen species grow above 3000 m, but only nine above 4000 m. The number of taxa (species and subspecies) growing in each country also varies considerably, with the highest noted in Kazakhstan (42), Tajikistan (40), and Kyrgyzstan (35). Of the 76 taxa of Stipa (species and subspecies) recorded in Middle Asia, 41 are confined to the region, with some being known only from a single country or mountain range. Distribution maps of selected species are provided.

Uncovering the role of a positive selection site of wax ester synthase/diacylglycerol acyltransferase in two closely related Stipa species in wax ester synthesis under drought stress.

Natural selection drives local adaptations of species to biotic or abiotic environmental stresses. As a result, adaptive phenotypic divergence can evolve among related species living in different habitats. However, the genetic foundation of this divergence process remains largely unknown. Two closely related alpine grass species, Stipa capillacea and Stipa purpurea, are distributed in different rainfall regions of northern Tibet. Here, we analyzed the drought tolerance of these two closely related Stipa species, and found that S. purpurea was more resistance to drought stress than S. capillacea. To further understand the genetic diversity behind their adaptation to drought environments, a comprehensive gene repertoire was generated using PacBio isoform and Illumina RNA sequencing technologies. Bioinformatics analyses revealed that differential transcripts were mainly enriched in the wax synthetic pathway, and a threonine residue at position 239 of WSD1 was identified as having undergone positive selection in S. purpurea. Using heterologous expression in the Saccharomyces cerevisiae mutant H1246, site-directed mutagenesis studies demonstrated that a positive selection site results in changes to the wax esters profile. This difference may play an important role in S. purpurea in response to drought conditions, indicating that S. purpurea has evolved specific strategies involving its wax biosynthetic pathway as part of its long-term adaptation to the Qinghai-Tibet Plateau.

Microbial diversity in the rhizosphere soils of three Stipa species from the eastern Inner Mongolian grasslands

Rhizosphere soil microorganisms affect the diversity and ecological distribution of aboveground plants and play an important role in the functions of terrestrial ecosystems. Using high-throughput sequencing, we have investigated the rhizosphere soil microbial communities of three species of Stipa from six plots, in the eastern steppe of Inner Mongolia, and analyzed the relationship between microbial diversity and vegetation diversity and soil physicochemical characteristics. The dominant bacteria phyla were: Actinobacteria, 31.73–44.73%; Proteobacteria, 15.79–23.85%; Acidobacteria, 9.42–15.14%; and Chloroflexi, 4.90–13.60%. While the dominant fungi phyla were: Ascomycota, 16.93–82.12%; Basidiomycota, 2.44–81.28%; and Zygomycota, 0.40–18.92%. Principal coordinates analysis (PCoA) indicated that the soil microbial community compositions in the Stipa baicalensis steppe in Hulunbuir and the Stipa krylovii steppe in the Xilingol plots, were significantly different from the others. The species characteristics of the plant communities were different in each plot for the vegetation diversity factors, the Shannon Weiner index, Simpson index, and the importance value indices of the Stipa and Leymus chinensis significantly affected the community structures of the bacteria and fungi. Among the physicochemical soil parameters, soil pH, ammonium nitrogen (AN), and sucrase (SC), significantly affected the community structures of the bacteria and fungi, and were inseparable from the interactions between the microorganisms and environmental factors. We found that microbial community diversity was complex in the rhizosphere soils of the Stipa, and that they were mainly affected by the vegetation diversity, soil pH, ammonium nitrogen, and soil sucrase activities. These results improve our understanding of the correlations between the Stipa rhizosphere soil microorganisms and the environmental factors, and provide guidance for future research on the distribution characteristics and growth of the Stipa.

Contrasting responses of steppe Stipa ssp. to warming and precipitation variability.

Climate change, characterized by warming and precipitation variability, restricted the growth of plants in arid and semiarid areas, and various functional traits are impacted differently. Comparing responses of functional traits to warming and precipitation variability and determining critical water threshold of dominate steppe grasses from Inner Mongolia facilitates the identification and monitoring of water stress effects. A combination of warming (ambient temperature, +1.5°C and +2.0°C) and varying precipitation (−30%, −15%, ambient, +15%, and +30%) manipulation experiments were performed on four Stipa species (S. baicalensis, S. bungeana, S. grandis, and S. breviflora) from Inner Mongolia steppe. The results showed that the functional traits of the four grasses differed in their responses to precipitation, but they shared common sensitive traits (root/shoot ratio, R/S, and specific leaf area; SLA) under ambient temperature condition. Warming increased the response of the four grasses to changing precipitation, and these differences in functional traits resulted in changes to their total biomass, with leaf area, SLA, and R/S making the largest contributions. Critical water thresholds of the four grasses were identified, and warming led to their higher optimum precipitation requirements. The four steppe grasses were able to adapt better to mild drought (summer precipitation decreased by 12%–28%) when warming 1.5°C rather than 2.0°C. These results indicated that if the Paris Agreement to limit global warming to 1.5°C will be accomplished, this will increase the probability for sustained viability of the Stipa steppes in the next 50–100 years.

Optimization, characterization and hepatoprotective effect of polysaccharides isolated from Stipa parviflora Desf. against CCl4 induced liver injury in rats using surface response methodology (RSM).

The roots of Stipa species have been used for treatment and prevention of a various number of diseases. To the best of my knowledge, little information is regarding the antioxidant and hepatoprotective activities of polysaccharides from Stipa parviflora (SPP). Hence the polysaccharides from this plant sample have been investigated here. In addition, Box-Behnken design and response surface methodology were used to optimize the hot extraction conditions. The optimal conditions were determined as: extraction time 120 min, extraction temperature 70 °C and ratio of water to raw material 30. Crude SPP was composed of mannose, ribose, glucose, galactose, pyranose and arabinose. In addition, the SPP showed a strong antioxidant capacity in vitro. In vivo experiments showed that CCl4 treatment caused significant oxidative damage in hepatic tissues, whereas these problems were inhibited by SPP treatment. Hepatoprotective potential of SPP was evaluated by estimating the levels of serum markers like ALT and AST levels. SPP treated rat liver anti-oxidant parameters (SOD, CAT and GPx) were significantly antagonized for the pro-oxidant effect of CCl4. Histopathological studies proved that the SPP extract has significant hepatoprotective activity. In conclusion, the SPP fraction isolated from S. parviflora showed significant hepatoprotective potential which could be related to active compounds present in this fraction.