Wild Grasses Research Articles

Genome compartmentalization predates species divergence in the plant pathogen genus Zymoseptoria

BackgroundAntagonistic co-evolution can drive rapid adaptation in pathogens and shape genome architecture. Comparative genome analyses of several fungal pathogens revealed highly variable genomes, for many species characterized by specific repeat-rich genome compartments with exceptionally high sequence variability. Dynamic genome structure may enable fast adaptation to host genetics. The wheat pathogen Zymoseptoria tritici with its highly variable genome, has emerged as a model organism to study genome evolution of plant pathogens. Here, we compared genomes of Z. tritici isolates and of sister species infecting wild grasses to address the evolution of genome composition and structure.ResultsUsing long-read technology, we sequenced and assembled genomes of Z. ardabiliae, Z. brevis, Z. pseudotritici and Z. passerinii, together with two isolates of Z. tritici. We report a high extent of genome collinearity among Zymoseptoria species and high conservation of genomic, transcriptomic and epigenomic signatures of compartmentalization. We identify high gene content variability both within and between species. In addition, such variability is mainly limited to the accessory chromosomes and accessory compartments. Despite strong host specificity and non-overlapping host-range between species, predicted effectors are mainly shared among Zymoseptoria species, yet exhibiting a high level of presence-absence polymorphism within Z. tritici. Using in planta transcriptomic data from Z. tritici, we suggest different roles for the shared orthologs and for the accessory genes during infection of their hosts.ConclusionDespite previous reports of high genomic plasticity in Z. tritici, we describe here a high level of conservation in genomic, epigenomic and transcriptomic composition and structure across the genus Zymoseptoria. The compartmentalized genome allows the maintenance of a functional core genome co-occurring with a highly variable accessory genome.

Effect of different in vitro and in vivo variables on the efficiency of doubled haploid production in Triticum aestivum L. using Imperata cylindrica-mediated chromosome elimination technique

Development of doubled haploid (DH) plants in wheat is an important technique for establishment of completely homozygous lines in the shortest time frame. In this study, we standardized the in vitro and in vivo variables for the production of wheat DH plants via crossing of three spring wheat genotypes with a wild grass (Imperata cylindrica). The experiment involves testing new treatments and protocol modifications for 2 years. Wheat florets were pollinated with I. cylindrica pollen after 2 days of emasculation, and next day pollinated spikes were injected with different auxin analogues: 100 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) or 100 mg/l 3,6-dichloro-2-methoxybenzoic acid (dicamba) or 50 mg/l 2,4-D + 50 mg/l dicamba. A combination of 50 mg/l 2,4-D and 50 mg/l dicamba was superior to other treatments having maximum haploid embryos and haploid plants developed per emasculated florets. The responsiveness of embryo formation to the addition of silver nitrate (AgNO3) (the ethylene inhibitor) with the auxin treatments showed that the presence of silver nitrate in the medium may not be essential for wheat embryo induction. Time of embryo rescue had a significant effect on embryo and haploid plant production. The most successful time for embryo rescue was 24 days after pollination (DAP) resulting in maximum haploid plants developed (40% in wheat variety AKYK92 and 25% each in variety HD2888 and HS542). The immature embryos were cultured in different media, i.e. Murashige and Skoog (MS), half-strength MS, modified MS media, Gamborg’s B5 and modified B5 media. Maximum number of haploid plants were found in half-strength MS media in all accessions (60.0%) followed by modified MS media (40.00%). For colchicine concentration, during 2016–2017, maximum numbers of DHs with less plant mortality were obtained at 0.08 and 0.06% dose. Taking into account the first year results, refinement of the dose in the second year showed that colchicine doses of 0.08 and 0.075% were the best dose for maximizing DH induction in wheat; however, in this case the number of examined plants was very small. Therefore, we can treat the two doses as a guide for further research on larger samples.

The Comparison of Skin Prick Test Results of the Refugees with the Citizens of the Republic of Turkey with Atopic Asthma

Amaç: Astım ve atopi çevresel maruziyetler ile değişkenlik gösterir. Göç ve Mültecilikte Alerjik astım hastaları için dezavantajlı grupta yer alır. Materyal ve Metod: Kesitsel tasarımlı 431 hastada, Ocak 2015-2017 tarihleri arasında, Atopik astımlı Türkiye Cumhuriyeti vatandaşı ile Çadır kampta yaşayan Suriyeli Mültecilerin Deri Prick Test (DPT) sonuçlarının değerlendirilmesi amaçlandı. Bulgular: Atopik Astım tanılı %45,7 Suriyeli Mülteciler olmak üzere toplam 431 hastaya SPT yapıldı. Kadın cinsiyet %75,4 ‘tür. Yaş ortalaması 30,5 ’tir. Hem TC vatandaşı hem de Mültecilerde en çok görülen alerjen Ev tozu akarıdır. Uyruğa göre: Mantar karışımı (13,343/0,000), Hamam Böceği (8,541/0,003) ve Tahıl karışımına (6,556/0,011) gruplar arasında anlamlı fark izlendi. Cinsiyete göre: Mantar Karışımı (6,173/0,013) ve Hamam Böceğine (4,495/0,034) gruplar arasında anlamlı fark izlendi. Yaş gruplarına göre: 17-34 yaş grubunda Mantar Karışımına (21,567/0,000), 45 ve üzeri yaş grubunda ise Ağaç polenine (6,062/0,048) karşı gruplarda anlamlı fark bulunmuştur. Sonuç: Göç ve Mültecilik durumlarında Alerjik Astım önemli bir sağlık sorunudur. TC vatandaşı ve Mültecilerde en sık alerjen pozitifliği ev tozu akarında görülmektedir. Suriyeli Mültecilerde sırayla Ev tozu akarı, Ot karışımı ve Mantar karışımı şeklindedir. Bu çalışma Mültecilerde Aeroalerjenleri gösteren ilk çalışma olmasıyla literatüre katkı sunacaktır.

Antiviral Activity of Extracts from Wild Grasses against Epstein-Barr Virus and Induction of Apoptosis in Epstein-Barr Virus-Positive Lymphoblastoid Cells

Antiviral Activity of Extracts from Wild Grasses against Epstein-Barr Virus and Induction of Apoptosis in Epstein-Barr Virus-Positive Lymphoblastoid Cells

The unique disarticulation layer formed in the rachis of Aegilops longissima probably results from the spatial co-expression of Btr1 and Btr2.

The brittle rachis trait is a feature of many wild grasses, particularly within the tribe Triticeae. Wild Hordeum and Triticum species form a disarticulation layer above the rachis node, resulting in the production of wedge-type dispersal units. In Aegilops longissima, only one or two of the nodes in the central portion of its rachis are brittle. In Triticeae species, the formation of a disarticulation layer above the rachis node requires the co-transcription of the two dominant and complementary genes Btr1 and Btr2. This study aims to establish whether homologues of Btr1 and/or Btr2 underlie the unusual brittle rachis phenotype observed in Ae. longissima. Scanning electron microscopy was used to examine the disarticulation surfaces. Quantitative RT-PCR and RNA in situ hybridization experiments were used to identify gene expression in the immature inflorescence. Analysis based on scanning electron microscopy was able to demonstrate that the disarticulation surfaces formed in the Ae. longissima rachis are morphologically indistinguishable from those formed in the rachises of wild Hordeum and Triticum species. RNA in situ hybridization showed that in the immature Ae. longissima inflorescence, the intensity of Btr1 transcription varied from high at the rachis base to low at its apex, while that of Btr2 was limited to the nodes in the central to distal portion of the rachis. The disarticulation pattern shown by Ae. longissima results from the limitation of Btr1 and Btr2 co-expression to nodes lying in the centre of the rachis.

Autochthonous halotolerant plant growth-promoting rhizobacteria promote bacoside A yield of Bacopa monnieri (L.) Nash and phytoextraction of salt-affected soil

Phytoremediation is a promising approach for reclamation of salt-affected soil. Phytoextraction is the most commonly used process, which exploits plants to absorb, immobilize, and accumulate salt in their shoots. In this study, halotolerant plant growth-promoting rhizobacteria (PGPR) were isolated from the rhizosphere of wild grasses growing naturally in salt-affected areas of Lucknow, Uttar Pradesh (India) and were tested for their efficacies of salt-tolerance and plant growth-promoting (PGP) abilities. Based on 16S rRNA sequences, the most efficient halotolerant isolates possessing PGP traits were identified as Pseudomonas plecoglossicida (KM233646), Acinetobacter calcoaceticus (KM233647), Bacillus flexus (KM233648), and Bacillus safensis (KM233652). Application of these isolates as bio-inoculants significantly (P < 0.05) increased the growth and bacoside A yield of a medicinal plant, Bacopa monnieri (L.) Nash, grown on natural salt-affected soil. The phytoremediation of salt-affected soil was evident by the substantial increase in shoot Na+:K+ ratio of bio-inoculant-treated plants. When compared to un-inoculated control plants, the soil physico-chemical properties of bio-inoculant-treated plants were improved. The shoot and root biomass (fresh and dry weights), soil enzymes, and soil nutrient parameters showed significant positive correlations with the shoot Na+:K+ ratio. Consequently, the halotolerant PGPR screened in this study could be useful for the reclamation of saline soils concomitant with improved plant growth and bacoside A yield.

Structure and diversity of Fusarium communities inhabiting non-cultivated grass inflorescences in New York State

The structure and diversity of wild grass spike-inhabiting Fusarium communities are not well understood. Fifteen common, non-cultivated grasses were surveyed across two years, regions, and land uses for spike-dwelling Fusarium spp. Eleven fungal species were identified from 857 isolates, including two, F. camptoceras and F. lactis, not recorded previously in New York state or on grass hosts. Species diversity and community structure varied by year and region. Land use and host community did not influence Fusarium communities, and no species-specific grass-Fusarium associations were detected. Fusarium communities were divided into two categories, those dominated by F. graminearum and those dominated by F. sporotrichioides. The community formation process is relevant to disease prediction and toxin monitoring in cropping systems as well as to land management practices at the intersection of agricultural and natural spaces.

The Incidence of Fusarium graminearum in Wild Grasses is Associated With Rainfall and Cumulative Host Density in New York.

The movement of plant pathogens between cultivated and natural host communities can result in lost agricultural production and altered microbial or plant biodiversity. Fusarium graminearum incidence was studied in wild grass hosts for 3 years to better understand the ecology of this plant pathogen at the interface of crop fields and nonagricultural environments. Research sites (n = 23) were spread between regions of high and low agricultural production and included both agricultural and nonagricultural fields. Pathogen incidence in living grass spikes and senesced, overwintered stems varied between regions of New York and was lowest in a region with sparser agricultural production (P = 0.001). However, pathogen incidence within regions was similar at both agricultural and nonagricultural sites. The groundcover of crop and wild hosts within 1 km of sample sites were equally effective predictors of pathogen incidence, indicating either host group may drive pathogen spread. Rainfall in the 8 weeks preceding sample collection was strongly correlated with F. graminearum incidence in grasses, as well as an increased prevalence of F. graminearum in Fusarium spp. communities (P = 0.001). Grass species diversity was not associated with a reduction in pathogen incidence, and F. graminearum incidence did not vary among the most well-sampled grasses. These results indicate the pathogen colonizes and spreads in noncultivated grasses in a manner consistent with existing concepts of pathogen epidemiology in cereal crops. Increasing host acreage, whether cultivated or not, could drive the colonization of grasses in remote or protected environments, potentially altering their microbial communities.

The effects of a known exposure source on Pb isotopes in bones from Pb-dosed cows

Pb accumulates in bone over long periods of time, and the isotopic effects of this accumulation are poorly studied. The use of Pb isotopes in bones as a metric of exposure requires additional constraints on the relationship between the isotopic composition of the exposure source and resulting isotopic composition of the bone. Here, we present a Pb isotope study of two cows that were associated with the blood Pb proficiency testing program at the University of Wisconsin-Madison State Laboratory of Hygiene (WSLH). These two cows were born and raised under the same conditions on the same farm, but were subjected to different levels of Pb exposure during that time period. Pb isotopes were measured in femur bones subsampled from each cow and the Pb isotopic composition of the exposure source (Pb nitrate) used for dosing the animals was also measured. Pb isotopic compositions of nearby (<0.5 km) wild grasses, silage, well water, and other potential environmental sources were measured to obtain the background Pb signal. Our data show that the Pb isotopic compositions of the cow bones reflect a mixture between background Pb sources mostly in the diet and the Pb isotopic composition of the Pb nitrate exposure source. The bones approach but do not attain the Pb isotopic composition of the exposure source at the levels of exposure in this study. Using estimates for daily food and water consumption, we are able to evaluate the relative contributions of different sources of Pb to the isotopic composition of the bone. The data show that the Pb isotopic composition of bone provides a weighted average of bioaccumulated Pb sources. Additional bone major and trace element composition data show that Pb competition with certain other trace elements in Ca substitution sites depends on the degree of Pb exposure. This result has implications for the use of bone in exposure studies, as well as the use of bone to understand background Pb signals in the environment.

Identifying sources and year classes contributing to invasive grass carp in the Laurentian Great Lakes

Relative contributions of aquaculture-origin and naturally-reproduced grass carp (Ctenopharyngodon idella) in the Laurentian Great Lakes have been unknown. We assessed occurrence and distribution of aquaculture-origin and wild grass carp in the Great Lakes using ploidy and otolith stable oxygen isotope (δ18O) data. We inferred natal river and dispersal from natal location for wild grass carp using otolith microchemistry and estimated ages of wild and aquaculture-origin fish to infer years in which natural reproduction and introductions occurred. Otolith δ18O indicated that the Great Lakes contain a mixture of wild grass carp and both diploid and triploid, aquaculture-origin grass carp. Eighty-eight percent of wild fish (n = 49 of 56) were caught in the Lake Erie basin. Otolith microchemistry indicated that most wild grass carp likely originated in the Sandusky or Maumee rivers where spawning has previously been confirmed, but results suggested recruitment from at least one other Great Lakes tributary may have occurred. Three fish showed evidence of movement between their inferred natal river in western Lake Erie and capture locations in other lakes in the Great Lakes basin. Age estimates indicated that multiple year classes of wild grass carp are present in the Lake Erie basin, recruitment to adulthood has occurred, and introductions of aquaculture-origin fish have happened over multiple years. Knowledge of sources contributing to grass carp in the Great Lakes basin will be useful for informing efforts to prevent further introductions and spread and to develop strategies to contain and control natural recruitment.

Caps DNA Barcoding for Field Laboratory Identification of Grass Species (British Grasses as a Model)

Abstract The true grasses (Poaceae) comprise one of the largest plant families on earth. The group is peerless in its contribution to global agricultural production and its members dominate many of the world’s most important habitats. However, morphological diagnosis of wild grasses is notoriously problematic and it is often impossible in the absence of flowering individuals. The advent of DNA barcoding provided a useful tool to address this problem for larger-scale or longer-term studies but the need for sequencing precludes its use in a field laboratory context or in situations where either funding or time is limited. Here, a chloroplast DNA (cpDNA)-based Cleaved Amplified Polymorphic Sequence (CAPS) system of molecular species diagnosis that has the capacity to address this problem is presented using British grasses as a model. First, PCRs were performed using universal primer pairs targeting 21 regions of the chloroplast genome in authenticated representatives of the 117 grass species from the British Isles, and universal amplification for all loci targeted was demonstrated. Second, 54 restriction enzymes were applied on amplification products generated from all species. There were 10 locus-enzyme combinations (with the highest variation) that had the best diagnostic utility for the 117 grass species.CAPS analysis on 16 representatives of three genera (Calamagrostis, Phleum, and Agrostis) was then used to illustrate the potential utility of the pipeline for establishing a field-laboratory screen of species identity. CAPS DNA barcoding system developed here may have ecological, conservation, and commercial applications. However, it has limited possibilities for intraspecific differentiation due to the highly conserved nature of loci targeted within species.

Significant host- and environment-dependent differentiation among highly sporadic fungal endophyte communities in cereal crops-related wild grasses.

Endophytic fungi compose a significant part of plant microbiomes. However, while a small number of fungal taxa have proven beneficial impact, the vast majority of fungal endophytes remain uncharacterized, and the drivers of fungal endophyte community (FEC) assembly are not well understood. Here, we analysed FECs in three cereal crops-related wild grasses - Avena sterilis, Hordeum spontaneum and Aegilops peregrina - that grow in mixed populations in natural habitats. Taxa in Ascomycota class Dothideomycetes, particularly the genera Alternaria and Cladosporium, were the most abundant and prevalent across all populations, but there was also high incidence of basidiomyceteous yeasts of the class Tremellomycetes. The fungal community was shaped to large extent by stochastic processes, as indicated by high level of variation even between individuals from local populations of the same plant species, and confirmed by the neutral community model and Raup-Crick index. Nevertheless, we still found strong determinism in FEC assembly with both incidence and abundance data sets. Substantial differences in community composition across host species and locations were revealed. Our research demonstrated that assembly of FECs is affected by stochastic as well as deterministic processes and suggests strong effects of environment heterogeneity and plant species on community composition. In addition, a small number of taxa had high incidence and abundance in all of the 15 populations. These taxa represent an important part of the core FEC and might be of general functional importance.

A Clone Resource of Magnaporthe oryzae Effectors That Share Sequence and Structural Similarities Across Host-Specific Lineages.

The blast fungus Magnaporthe oryzae (syn. Pyricularia oryzae) is a destructive plant pathogen that can infect about 50 species of both wild and cultivated grasses, including important crops such as rice and wheat. M. oryzae is composed of genetically differentiated lineages that tend to infect specific host genera. To date, most studies of M. oryzae effectors have focused on the rice-infecting lineage. We describe a clone resource of 195 effectors of Magnaporthe species predicted from all the major host-specific lineages. These clones are freely available as Golden Gate-compatible entry plasmids. Our aim is to provide the community with an open source effector clone library to be used in a variety of functional studies. We hope that this resource will encourage studies of M. oryzae effectors on diverse host species.

Identifying food provenience using Sr/Ca ratio in human enamel

The strontium (Sr) concentration in bioapatite of human bone and teeth reflects the Sr concentration in food that is differentiated by two major factors: an abundance of Sr in local soils and the biopurification effect along the trophic levels. Eastern Syria is an area with a relatively high concentration of Sr within the Euphrates valley and a low concentration of Sr beyond the valley. For this reason, the strontium/calcium (Sr/Ca) ratio in human enamel retrieved from skeletons buried in cemeteries within the Euphrates valley may be used as a proxy for food provenience in a local population. A sample of human teeth (N = 72) from Tell Ashara and Tell Masaikh was divided into seven temporal subsets covering periods between c.2200 bce and the early 20th century ce. A significant difference in Sr/Ca values between temporal subsets is observed. The Sr/Ca values in later subsets are negatively correlated with δ13C values, indicating the wider exploitation of steppe areas outside the valley with more wild C4 grasses and a low Sr concentration. For periods with lower Sr/Ca values (c.2200–1900 bce and 19th–20th centuries ce) there is additional textual and isotopic evidence for food transportation from outside the river valley, supporting the interpretation of Sr/Ca values as a proxy for food provenience in this specific area.

Exclamation Points and Elliptical Hope: Reading Wild Grass against Modern Chinese Punctuation Reform

Exclamation Points and Elliptical Hope: Reading <i>Wild Grass</i> against Modern Chinese Punctuation Reform

An Ethnobotanical Study of the Genus Elymus1

Grains of domesticated grasses (Poaceae) have long been a global food source and constitute the bulk of calories in the human diet. While most contemporary grass domesticates consumed by humans are annual plants, there are over 7000 perennial grass species that remain largely unexplored for domestication purposes. Documenting ethnobotanical uses of wild perennial grasses could aid in the evaluation of candidate species for de novo crop development. In this study, we 1) provide an ethnobotanical survey of the perennial grass genus Elymus; and 2) investigate floret size variation in Elymus species used by people. We identified at least 21 taxa with recorded nutritional, medicinal, and/or material uses and at least 25 different indigenous communities associated with a use. The most common ethnobotanical use of Elymus in this survey is as forage, though at least 12 species are consumed by humans. Elymus species used for food warrant pre-breeding and future analyses to assess potential utility in perennial agricultural systems. We found average floret area does not differ significantly across geographic regions and among documented ethnobotanical uses, with the exception of species used for medicine in North America. A variety of Elymus species show promise for continued human use, and standing morphological variation in the genus should be further explored.

Genomic evidence for convergent evolution of gene clusters for momilactone biosynthesis in land plants

Momilactones are bioactive diterpenoids that contribute to plant defense against pathogens and allelopathic interactions between plants. Both cultivated and wild grass species of Oryza and Echinochloa crus-galli (barnyard grass) produce momilactones using a biosynthetic gene cluster (BGC) in their genomes. The bryophyte Calohypnum plumiforme (formerly Hypnum plumaeforme) also produces momilactones, and the bifunctional diterpene cyclase gene CpDTC1/HpDTC1, which is responsible for the production of the diterpene framework, has been characterized. To understand the molecular architecture of the momilactone biosynthetic genes in the moss genome and their evolutionary relationships with other momilactone-producing plants, we sequenced and annotated the C. plumiforme genome. The data revealed a 150-kb genomic region that contains two cytochrome P450 genes, the CpDTC1/HpDTC1 gene and the "dehydrogenase momilactone A synthase" gene tandemly arranged and inductively transcribed following stress exposure. The predicted enzymatic functions in yeast and recombinant assay and the successful pathway reconstitution in Nicotiana benthamiana suggest that it is a functional BGC responsible for momilactone production. Furthermore, in a survey of genomic sequences of a broad range of plant species, we found that momilactone BGC is limited to the two grasses (Oryza and Echinochloa) and C. plumiforme, with no synteny among these genomes. These results indicate that while the gene cluster in C. plumiforme is functionally similar to that in rice and barnyard grass, it is likely a product of convergent evolution. To the best of our knowledge, this report of a BGC for a specialized plant defense metabolite in bryophytes is unique.

Mycelial biomass and concentration of loline alkaloids driven by complex population structure in Epichloë uncinata and meadow fescue (Schedonorus pratensis)

ABSTRACT Many efforts have been made to select and isolate naturally occurring animal-friendly Epichloë strains for later reinfection into elite cultivars. Often this process involves large-scale screening of Epichloë-infected wild grass populations where strains are characterized and alkaloids measured. Here, we describe for the first time the use of genotyping-by-sequencing (GBS) on a collection of 217 Epichloë-infected grasses (7 S. arundinaceum, 4 L. perenne, and 206 S. pratensis). This genotyping strategy is cheaper than complete genome sequencing, is suitable for a large number of individuals, and, when applied to endophyte-infected grasses, conveniently genotypes both organisms. In total, 6273 single nucleotide polymorphisms (SNPs) in the endophyte data set and 38 323 SNPs in the host data set were obtained. Our findings reveal a composite structure with three distinct endophyte clusters unrelated to the three main S. pratensis gene pools that have most likely spread from different glacial refugia in Eurasia. All three gene pools can establish symbiosis with E. uncinata. A comparison of the endophyte clusters with microsatellite-based fingerprinting of the same samples allows a quick test to discriminate between these clusters using two simple sequence repeats (SSRs). Concentrations of loline alkaloids and mycelial biomass are correlated and differ significantly among the plant and endophyte subpopulations; one endophyte strain has higher levels of lolines than others, and one specific host genotype is particularly suitable to host E. uncinata. These findings pave the way for targeted artificial inoculations of specific host-endophyte combinations to boost loline production in the symbiota and for genome association studies with the aim of isolating genes involved in the compatibility between meadow fescue and E. uncinata.

Diversity of foliar endophytes in a dioecious wild grass and their interaction with the systemic Epichloë

Abstract This study compares the culturable fungal endophytic community inhabiting leaves of Epichloe-infected (E+) and Epichloe-free (E-) plants of Poa bonariensis. Plants were collected from a wild population (dioecious species) where E+ and E- plants co-exist. Fungal endophytes were isolated and then morphology and ribosomal DNA internal transcribed spacer sequences were used for the identification of isolates. In total 24 different taxa of non-Epichloe (NE) endophytes were identified. No significant differences were found in richness and diversity indexes of NE-endophytes between E+ and E- plants, or between pistillate (P) and staminate (S) plants. When we analyzed these effects based on the count of the most abundant genera, Alternaria and Stemphylium infection frequencies decreased in S plants, while in E+ plants, this tendency was observed for Alternaria. Our results suggest that Epichloe and the sex of the host plant may modulate some of the dominant foliar endophytic fungal taxa.

Genetic variability and structure of an important wild steppe grass Psathyrostachys juncea (Triticeae: Poaceae) germplasm collection from north and central Asia.

Russian wildrye, Psathyrostachys junceus (Fisch.) Nevski, is an important wild steppe perennial grass, which is characterized by longevity and short robust rhizomes. It also has highly resistance in grazing and abiotic stress. In this study, the genetic diversity of eleven P. juncea wild germplasms from north and central Asia was investigated using AFLP markers. The P. juncea populations were divided into three clades in both UPGMA dendrogram and PCoA clustering corresponding to the three genetic memberships in STRUCTURE analysis. The genetic specificity of Xinjiang (XJ) populations was revealed by the highest Ne (1.5411) and Hj (0.3553) and their dispersion shown in UPGMA. High inbreeding coefficient (Wright’s F statistics, f = 0.496, Fst = 0.128) was observed although a moderate degree of gene flow (Nm = 1.4736) existed, that may ascribe to habitat fragmentation or the low seedling recruitment, which ultimately resulted in decrease of population size and their genetic diversity. The key factors inducing moderate genetic differentiation detected in this study were isolation by distance (IBD), climatic variabilities and geographical barriers. All these results provide insights into the study of genetic status and germplasm collecting of Russian wildrye.