Endemic Grass Research Articles

Pyricularia Are Mostly Host-Specialized with Limited Reciprocal Cross-Infection Between Wheat and Endemic Grasses in Minas Gerais, Brazil.

Wheat blast, caused by Pyricularia oryzae Triticum (PoT), is an emerging threat to global wheat production. The current understanding of the population biology of the pathogen and epidemiology of the disease has been based on phylogenomic studies that compared the wheat blast pathogen with isolates collected from grasses that were invasive to Brazilian wheat fields. In this study, we performed a comprehensive sampling of blast lesions in wheat crops and endemic grasses found in and away from wheat fields in Minas Gerais. A total of 1,368 diseased samples were collected (976 leaves of wheat and grasses and 392 wheat heads), which yielded a working collection of 564 Pyricularia isolates. We show that, contrary to earlier implications, PoT was rarely found on endemic grasses, and, conversely, members of grass-adapted lineages were rarely found on wheat. Instead, most lineages were host-specialized, with constituent isolates usually grouping according to their host of origin. With regard to the dominant role proposed for signalgrass in wheat blast epidemiology, we found only one PoT member in 67 isolates collected from signalgrass grown away from wheat fields and only three members of Urochloa-adapted lineages among hundreds of isolates from wheat. Cross-inoculation assays on wheat and a signalgrass used in pastures (U. brizantha) suggested that the limited cross-infection observed in the field may be due to innate compatibility differences. Whether or not the observed level of cross-infection would be sufficient to provide an inoculum reservoir, or serve as a bridge between wheat growing regions, is questionable and, therefore, deserves further investigation.

A Reevaluation of Phylogenomic Data Reveals that Current Understanding in Wheat Blast Population Biology and Epidemiology Is Obfuscated by Oversights in Population Sampling.

Wheat blast, caused by the Pyricularia oryzae Triticum lineage (PoT), first emerged in Brazil and quickly spread to neighboring countries. Its recent appearance in Bangladesh and Zambia highlights a need to understand the disease's population biology and epidemiology so as to mitigate pandemic outbreaks. Current knowledge is mostly based on characterizations of Brazilian wheat blast isolates and comparison with isolates from non-wheat, endemic grasses. These foregoing studies concluded that the wheat blast population lacks host specificity and, as a result, undergoes extensive gene flow with populations infecting non-wheat hosts. Additionally, based on genetic similarity between wheat blast and isolates infecting Urochloa species, it was proposed that the disease originally emerged via a host jump from this grass and that Urochloa likely plays a central role in wheat blast epidemiology owing to its widespread use as a pasture grass. However, due to inconsistencies with broader phylogenetic studies, we suspected that these seminal studies had not actually sampled the populations normally found on endemic grasses and, instead, had repeatedly isolated members of PoT and the related Lolium pathogen lineage (PoL1). Re-analysis of the Brazilian data as part of a comprehensive, global, phylogenomic dataset that included a small number of South American isolates sampled away from wheat confirmed our suspicion and identified four new P. oryzae lineages on grass hosts. As a result, the conclusions underpinning current understanding in wheat blast's evolution, population biology, and epidemiology are unsubstantiated and could be equivocal.

Endemic Grasses of India

The paper provides a detailed list of endemic grass species of India and their distributional status. This includes a total of 327 taxa belonging to 82 genera. The data has been compiled from available literature both offline and online, of these 190 taxa are steno endemics and 137 are holo endemics. Inventory of species has been supplemented with distribution data and ICUN status.

Diverse endophytic fungi colonise wild endemic grasses and sedges in Hyrcanian Forests

Fungal endophytes were identified associated with leaves, stems and roots of wild grasses (Poaceae) and sedges (Cyperaceae) residing in Hyrcanian Forests, some of the most unique and unspoiled forest systems in the world. The plants grew in two climatically-distinct regions of Golestan and Semnan provinces of Iran. Endophytic fungi isolated from these plants were categorised into 27 morphogroups based on physical attributes measured in vitro. Sequence diversity was estimated from the internal transcribed spacer (ITS) region of the ribosomal DNA gene. Of the 53 isolates characterised in this study, identification of only one isolate was conclusive at the species level. Twenty-eight isolates were identified to the level of genus, belonging to seven families and six orders, six isolates to the level of family, 13 at the level of order, one to the super family, and four to the subphylum. Members of the genera Fusarium and Alternaria, and of the families Necteriaceae, Pleosporaceae and Trichocomaceae were the most abundant fungal endophytes identified. Several endophytes resembled those of fungal pathogens. This study advances our understanding of endophytic fungal communities of indigenous grasses and sedges in Hyrcanian Forests.

Occurrence of <I>Chrysopogon velutinus</I> (Hook. F.) Bor (Poaceae: Andropoginae) in Eastern Ghats of Telangana.

Chrysopogon velutinus (Hook.f.) Bor, an endemic grass collected from other than type locality in Eastern Ghats of Telangana, India. Brief description and photographs were provided for easy identification.

Rediscovery and IUCN threat assessment of Themeda saxicola (Poaceae: Andropogoneae), an endemic grass from the Eastern Ghats, India

Themeda saxicola is an endemic perennial grass rediscovered after laps of 67 years from the Raisili hill (type locality) and Deomali hill, from the Eastern Ghats in the Koraput district of Odisha. The detailed description along with colour photographs of the habitats, habit and floral parts are provided for easy identification of the species. In addition, distribution map and IUCN threat category assessment are also provided.

Strategies for reintroduction and conservation of Gymnopogon doellii, an endemic grass at risk of extinction

Abstract The Brazilian savanna, regionally known as Cerrado, is characterized by a great diversity of physiognomies and holds the highest species diversity and level of endemism among world savannas. However, due mainly to agribusiness, this vegetation is among the most threatened ones, currently presenting alarming rates of extinction. Among the species present in the “red list” we find the endemic Gymnopogon doellii, a grass whose distribution is restricted to a few sites. In the Federal District and surroundings, for example, only one population, with scattered subpopulations, is known, within the limits of the Brasilia National Park. By this study we raised information related to the biology of G. doellii, as population size and distribution, genetic variability and germination characteristics. Besides, we produced seedlings in greenhouse, planted in different physiognomies of the Cerrado and followed them for almost four years to check for their survival, growth and fruiting under natural conditions. Seedlings transplanted to the field presented high rates of recruitment (> 25%), growth patterns similar to wild plants and produced viable caryopses. We recommend transplanting of individuals of G. doellii for both in situ conservation as well as for the revegetation of degraded areas of the Cerrado.

Loss of fungal symbionts at the arid limit of the distribution range in a native Patagonian grass—Resource eco‐physiological relations

Abstract Crucial to our understanding of plant ecology is the consideration of the eco‐physiological responses and constraints of plant–fungal symbioses throughout the native distribution range of their host. We examined key eco‐physiological roles of two co‐occurring fungal symbionts [Epichloë endophytes and arbuscular mycorrhizal fungi (AMF)] in the endemic grass Hordeum comosum across a wide bioclimatic gradient and contrasting grazing severity. We sampled H. comosum plants along four humid‐to‐arid transects in Patagonia, Argentina, covering its entire distribution range and determined Epichloë presence, AMF root colonization, nitrogen and phosphorus concentration, intrinsic water‐use efficiency (iWUE, the ratio of photosynthesis to stomatal conductance) and 18O‐enrichment of cellulose in shoots. Root colonization by AMF increased with Epichloë presence. All plants hosted Epichloë in the humid range of the gradient, but symbioses occurrence decreased towards arid sites which also displayed severe grazing symptoms at site level. Symbiosis with Epichloë correlated positively with shoot nitrogen concentration in the centre of the distribution range, and with shoot phosphorus concentration across the entire distribution range. The site‐level relationship of AMF colonization with 18O‐enrichment and iWUE suggested that mycorrhiza boosted stomatal conductance in humid environments but curbed it in arid environments. While the interpretation of interactions and potential causalities from observational studies should be done with caution, this study demonstrates distinct correlations between plant–fungal symbiont associations and key resource parameters (phosphorus, nitrogen and iWUE vs. 18O‐enrichment). Such correlations may suggest particular functional roles for these symbionts in the ecology of their host plant. A free Plain Language Summary can be found within the Supporting Information of this article.

Two endemic grasses (Poaceae): Additions to the flora of Telangana, India

Two endemic grass species viz., Dimeria bialata C.E.C. Fisch. and Heteropogon polystachyos (Roxb.) Schult. are strictly endemic to India have been reported from Eastern Ghats of Telangana as new additions to the grass flora of Telangana State, India. A brief description and colour photo plates are provided for easy identification.

Seeing the forest for the trees-and the grasses: revisiting the evidence for grazer-maintained grasslands in Madagascar's Central Highlands.

Seeing the forest for the trees-and the grasses: revisiting the evidence for grazer-maintained grasslands in Madagascar's Central Highlands.

<p><strong>Rediscovery of <em>Parahyparrhenia bellariensis</em> (Poaceae: Andropogoneae): A presumed extinct grass from Andhra Pradesh, India</strong></p>

Parahyparrhenia bellariensis, an extremely rare and highly narrow endemic grass, has been rediscovered after almost 184 years from Cuddapah [Kadapa] district, Andhra Pradesh. The first description of its complete habit, basal portion and other features of the spikelets are provided along with new locality of its occurrence. In addition, photographs of the habitats, live plants, and a key to distinguish two Indian endemic species, distribution map and illustration are provided. As per the IUCN Red List Criteria this species is assessed here as Critically Endangered (CR). In order to facilitate the prospective conservation of this grass, we have discussed about the peculiarity of its habitat.

Madagascan highlands: originally woodland and forest containing endemic grasses, not grazing-adapted grassland.

Long considered a consequence of anthropogenic agropastoralism, the origin of Madagascar's central highland grassland is hotly disputed. Arguments that ancient endemic grasses formed grassland maintained by extinct grazers and fire have been persuasive. Consequent calls to repeal fire-suppression legislation, burn protected areas, and accept pastoralism as the 'salvation' of endemic grasses mount, even as the International Union for Conservation of Nature (IUCN) declares 98% of lemurs face extinction through fire-driven deforestation. By analysing grass data from contemporary studies, and assessing endemic vertebrate habitat and feeding guilds, we find that although the grassland potentially dates from the Miocene, it is inhospitable to endemic vertebrates and lacks obligate grazers. Endemic grasses are absent from dominant grassland assemblages, yet not from woodland and forest assemblages. There is compelling evidence that humans entered a highland dominated by woodland and forest, and burned it; by 1000 current era (CE), grass pollens eclipsed tree pollens, reminiscent of prevailing fire-induced transformation of African miombo woodland to grassland. Endemic grasses are survivors from vanished woody habitats where grassy patches were likely small and ephemeral, precluding adaptive radiation by endemic vertebrates to form grazing-guilds. Today forests, relic tapia woodland, and outcompeted endemic grasses progressively retreat in a burning grassland dominated by non-endemic, grazing-adapted grasses and cattle.

Museomics Unveil the Phylogeny and Biogeography of the Neglected Juan Fernandez Archipelago Megalachne and Podophorus Endemic Grasses and Their Connection With Relict Pampean-Ventanian Fescues.

Oceanic islands constitute natural laboratories to study plant speciation and biogeographic patterns of island endemics. Juan Fernandez is a southern Pacific archipelago consisting of three small oceanic islands located 600–700 km west of the Chilean coastline. Exposed to current cold seasonal oceanic climate, these 5.8–1 Ma old islands harbor a remarkable endemic flora. All known Fernandezian endemic grass species belong to two genera, Megalachne and Podophorus, of uncertain taxonomic adscription. Classical and modern classifications have placed them either in Bromeae (Bromus), Duthieinae, Aveneae/Poeae, or Loliinae (fine-leaved Festuca); however, none of them have clarified their evolutionary relationships with respect to their closest Festuca relatives. Megalachne includes four species, which are endemic to Masatierra (Robinson Crusoe island) (M. berteroniana and M. robinsoniana) and to Masafuera (Alejandro Selkirk island) (M. masafuerana and M. dantonii). The monotypic Podophorus bromoides is a rare endemic species to Masatierra which is only known from its type locality and is currently considered extinct. We have used museomic approaches to uncover the challenging evolutionary history of these endemic grasses and to infer the divergence and dispersal patterns from their ancestors. Genome skimming data were produced from herbarium samples of M. berteroniana and M. masafuerana, and the 164 years old type specimen of P. bromoides, as well as for a collection of 33 species representing the main broad- and fine-leaved Loliinae lineages. Paired-end reads were successfully mapped to plastomes and nuclear ribosomal cistrons of reference Festuca species and used to reconstruct phylogenetic trees. Filtered ITS and trnTLF sequences from these genomes were further combined with our large Loliinae data sets for accurate biogeographic reconstruction. Nuclear and plastome data recovered a strongly supported fine-leaved Fernandezian clade where Podophorus was resolved as sister to Megalachne. Bayesian divergence dating and dispersal-extinction-cladogenesis range evolution analyses estimated the split of the Fernandezian clade from its ancestral southern American Pampas-Ventanian Loliinae lineage in the Miocene-Pliocene transition, following a long distance dispersal from the continent to the uplifted volcanic palaeo-island of Santa Clara-Masatierra. Consecutive Pliocene-Pleistocene splits and a Masatierra-to-Masafuera dispersal paved the way for in situ speciation of Podophorus and Megalachne taxa.

Performance of chlorophyll prediction indices for Eragrostis tef at Sentinel-2 MSI and Landsat-8 OLI spectral resolutions

As remotely sensed data becomes more readily available around the world, satellites such as Landsat-8 and Sentinel-2 have great potential to support precision agriculture. Sensors with high spectral and spatial resolutions are particularly optimal for limited land resource farmers to improve land management. The objective of this short communication is to assess the performance of Sentinel-2 and Landsat-8 multispectral bands for chlorophyll prediction using indices that were originally developed using imaging spectroscopy/hyperspectral data. Remotely sensed chlorophyll content measures are often utilized as a proxy of plant health. Performance of a group of chlorophyll prediction indices is tested for tef (Eragrostis tef), an endemic grass crop native to Ethiopia that forms a major component of Ethiopian diets and is grown by limited land resource farmers. Hyperspectral reflectance data captured in situ at the canopy level were convolved into bands approximating Landsat-8 and Sentinel-2 sensors, and a suite of chlorophyll prediction indices were computed and regressed against chlorophyll content. Results show that simple pigment indices employing wavelengths corresponding to the blue and ultra-blue bands performed best for predicting chlorophyll. The red-edge index computed using the Sentinel-2 bands also performed well. These findings suggest that publicly available, multispectral imagery can potentially substitute for hyperspectral data in chlorophyll prediction indices, thereby improving the accessibility of precision agriculture methods.

Genetic Diversity and Population Divergence of a Rare, Endemic Grass (Elymus breviaristatus) in the Southeastern Qinghai-Tibetan Plateau

Elymus breviaristatus is a grass species only distributed in the southeast of Qinghai-Tibetan Plateau (QTP), which has suffered from serious habitat fragmentation. Therefore, understanding patterns of genetic diversity within and among natural E. breviaristatus populations could provide insight for future conservation strategies. In this study, sequence-related amplified polymorphism markers were employed to investigate the genetic diversity and hierarchical structure of seven E. breviaristatus populations from QTP, China. Multiple measures of genetic diversity indicated that there is low to moderate genetic variation within E. breviaristatus populations, consistent with its presumed mating system. In spite of its rarity, E. breviaristatus presented high genetic diversity that was equivalent to or even higher than that of widespread species. Bayesian clustering approaches, along with clustering analysis and principal coordinate analysis partitioned the studied populations of E. breviaristatus into five genetic clusters. Differentiation coefficients (Fst, GST, etc.) and AMOVA analysis revealed considerable genetic divergence among different populations. BARRIER analyses indicated that there were two potential barriers to gene flow among the E. breviaristatus populations. Despite these patterns of differentiation, genetic distances between populations were independent of geographic distances (r = 0.2197, p = 0.2534), indicating little isolation by distance. Moreover, despite detecting a common outlier by two methods, bioclimatic factors (altitude, annual mean temperature, and annual mean precipitation) were not related to diversity parameters, indicating little evidence for isolation caused by the environment. These patterns of diversity within and between populations are used to propose a conservation strategy for E. breviaristatus.

Colonization routes, microevolutionary genetic structure and conservation concerns in a remote widespread insular endemic grass: the case of the Azorean tussock grass Deschampsia foliosa

AbstractPopulation genetic structure and diversity and phylogeographical dispersal routes were assessed for the Azorean endemic grass Deschampsia foliosa using AFLP markers. This species occurs on seven islands in the archipelago and a sampling of populations from the three main geographical groups of islands was used, covering its known distribution. Principal coordinates analyses (PCoAs), Bayesian analyses and phylogenetic networks revealed different degrees of admixture for the central group (C) populations and a clear differentiation for the western group (W) and São Miguel island (in the eastern group, E) populations. The best K values corresponded to nine and 11 genetic groups, which were also confirmed by analysis of molecular variance. A low but significant correlation between genetic data and geography was observed, with most relevant barriers to gene flow generally placed between sub-archipelagos. We suggest a west-to-east isolation by distance dispersal model across an island age continuum with Flores–Corvo (W) and Pico (C) at the extremes of the dispersal path. An alternative scenario, also supported by the genetic data, implies an initial colonization of São Jorge (C), dispersal within C and following bidirectional dispersal to the W and E. The phylogeographical framework detected might be related to island age and to highly destructive volcanic events, and it supports the occurrence of cryptic diversity within D. foliosa. Genetic diversity estimators were highest for Pico island populations (C), lowest for São Miguel (E) and Flores (W) populations, and more divergent for the Corvo population (W). Conservation measures should be taken to preserve the genetic structure found across sub-archipelagos and islands.

Epichloe novae-zelandiae, a new endophyte from the endemic New Zealand grass Poa matthewsii

ABSTRACTEpichloe endophytes (Clavicipitaceae) infect pooid grass genera worldwide but predominantly in the Northern Hemisphere, but appear to be rare in native grasses of the Southern Hemisphere. Because of benefits that hosts may receive from the symbiosis, Epichloe endophytes have been extensively studied and are considered important components of sustainable agriculture. There are only a few studies available on the incidence of endophyte infection in grasses of the Southern Hemisphere and most grass species have never been examined. Here we report on a survey of native grasses of New Zealand including 25 endemic or indigenous species. We sampled up to 10 plants per species at different sites from both the North and South Island of New Zealand and examined tissues microscopically for endophyte infection. Overall, only two species were found to be infected, Poa matthewsii (Matthew's bluegrass) and Dichelachne micrantha (short-hair plume grass). Based on analyses of tefA and tubB genes, both endophytes were found to be interspecific hybrids. The endophyte of the new host D. micrantha was previously described as Epichloe australiensis, while the endophyte of P. matthewsii is a new species named here E. novae-zelandiae. The new species is a hybrid derived from E. amarillans, E. bromicola and E. typhina subsp. poae. Alkaloid analyses in planta suggested that E. novae-zelandiae can produce small amounts of peramine, early pathway indole-diterpenes and ergot alkaloids, but no lolines or lolitrems. Target specific primers suggested the presence of genes for ergot alkaloids and peramine, but genes of only early pathway steps for the other alkaloids. Furthermore, genes for both mating type idiomorphs (MTA and MTB) were present, a single copy of MTA and two copies of MTB. Endophytes of native grasses may provide a genetic resource that could be exploited for developing pasture grass cultivars with improved performance.

Phytodiversity Inventorisation and Mapping of Shola Grasslands of Kodaikanal Wildlife Sanctuary, Western Ghats, India

During the course of floristic studies of Kodaikanal Wildlife Sanctuary, mapping of Shola grasslands and savannah of Kodaikanal wildlife sanctuary was done. In this study 7 grasslands were reported and categorized into 4 types based on species dominance. Apart from this, a total 155 angiospermic species of 33 families were reported, in which 42 are grass species and 113 are grassland associated species. Out of 155 total species, 13 are endemic grasses and 43 are endemic grassland associated species. Factors affecting the ecosystem of grasslands are given and conservation measures are suggested to protect the natural composition of the grasslands.

Seasonal variability of palatability and nutrient intake in different age groups of range sheep

ABSTRACT The study was designed to analyze the seasonal dynamics of the nutritive value of endemic plant species (Berberis lycium, Indigofera heterentha, Parrotiopsis jacquemontiana, Rosa macrophylla and Rosa webbiana) and composite pasture grasses in different age groups of sheep using double indicator method. Twenty Kashmir Merino sheep from the two age groups in each season of summer (June) and autumn (October) were selected and divided into Group I (about 4 months of age) and Group II (1–2 years of age) in a 2 × 2 factorial design. The metabolizable energy (ME) of plants and composite grasses range from 10.11 to 12.60 and 7.32 to 9.94 MJ/kg, respectively, across different seasons. The quality of plants and the composite grass samples, measured in terms of total digestible nutrients, ME, crude protein and fiber content deteriorated with the advancement of the season. Palatability, nutrient and mineral intake, D and relative feed quality values were better during the summer than the autumn season. ME intake in younger sheep (Group I) was deficient by 32.5% compared to maintenance requirements during the autumn season. It was found that adult sheep tend to optimize their energy requirements from pastures while younger sheep fail to do so. Abbreviations: ADF: Acid Detergent Fiber; ADL: Acid Detergent Lignin; Ca: Calcium; CP: Crude Protein; D value: Digestible organic matter in dry matter; DCP: Digestible Crude Protein; DMI: Dry Matter Intake; EE: Ether Extract; ME: Metabolizable Energy; NDF: Neutral Detergent Fiber; OM: Organic Matter; P: Phosphorus; RFI: Relative Feed Index; TDN: Total Digestible Nutrients

Rediscovery ofPacificella variabilis(Gastropoda: Achatinellidae) on Easter Island

The achatinellid Pacificella variabilis Odhner, 1922, is reported for the first time since its original description from its type locality, Easter Island (Rapa Nui), South Pacific Ocean, Chile. Specimens were found living on the bark of a lemon tree in Hanga Roa town and among the endemic grass Paspalum forsterianum on Motu Nui Islet. A redescription of the shell based on scanning electron microscopy (SEM) is provided. This represents the first report of the habitat of the species on Easter Island.