Poaceae Species Research Articles

Reproductive traits related to anemophily and insect visitors in two species of Poaceae from the Brazilian Atlantic rainforest

The floral biologies of two grass species occurring in the Brazilian Atlantic Forest, Bahia were examined to determine whether the morphological characteristics of their synflorescences, spikelets, and pollen grains were compatible with those expected for anemophily, and whether there was any biotic assistance in their pollination. Both Lasiacis ligulata Hitchc. & Chase (Panicoideae) and Olyra latifolia L. (Bambusoideae) have herbaceous habits, paniculate synflorescences, bifloral and unifloral spikelets, inconspicuous flowers, with pollen offered as a resource. L. ligulata is a homogamous species, while O. latifolia is protogynous. Their pollens are only available in the morning; the pollen grains of L. ligulata and O. latifolia are ornamented and contain starch, but without pollenkitt or lipids. Both species are visited by flies (Cecidomyiidae), beetles (Chrysomelidae), and ants (Brachymyrmex sp.) that possibly can aid in liberating pollen grains. The present study brings new data concerning the floral biology and anemophily of herbaceous Poaceae in the Brazilian Atlantic Rainforest, suggesting the insect-assisted anemophily in L. ligulata.

Tripogon uma-ganeshii (Poaceae: Chloridoideae: Tripogoninae), a new species from India

Tripogon uma-ganeshii, a new species of Poaceae from the Horsley hills of Chittoor district of Andhra Pradesh, India, is described and illustrated. The new species is allied to Tripogon tirumalae Chorghe et al., and T. trifidus Munro ex Stapf, in having 2-lobed lemma and median awn longer than the lemma length; but differs from Tripogon tirumalae, in length of leaf blades and spikes, number of florets in spikelets, size of the glumes, lemmas and paleas. It differs from Tripogon trifidus, in height of the culms, nature of leaf sheath, length of leaf blades, number of florets in spikelets and size of the glumes.

New biomolecular tools for aerobiological monitoring: Identification of major allergenic Poaceae species through fast real-time PCR.

Grasses (Poaceae) are very common plants, which are widespread in all environments and urban areas. Despite their economical importance, they can represent a problem to humans due to their abundant production of allergenic pollen. Detailed information about the pollen season for these species is needed in order to plan adequate therapies and to warn allergic people about the risks they take in certain areas at certain moments. Moreover, precise identification of the causative species and their allergens is necessary when the patient is treated with allergen‐specific immunotherapy. The intrafamily morphological similarity of grass pollen grains makes it impossible to distinguish which particular species is present in the atmosphere at a given moment. This study aimed at developing new biomolecular tools to analyze aerobiological samples and identifying major allergenic Poaceae taxa at subfamily or species level, exploiting fast real‐time PCR. Protocols were tested for DNA extraction from pollen sampled with volumetric and gravimetric methods. A fragment of the matK plastidial gene was amplified and sequenced in Poaceae species known to have high allergological impact. Species‐ and subfamily‐specific primer–probe systems were designed and tested in fast real‐time PCRs to evaluate the presence of these taxa in aerobiological pollen samples. Species‐specific systems were obtained for four of five studied species. A primer–probe set was also proposed for the detection of Pooideae (a grass subfamily that includes also major cereal grains) in aerobiological samples, as this subfamily includes species carrying both grass allergens from groups 1 and 5. These, among the 11 groups in which grass pollen allergens are classified, are considered responsible for the most frequent and severe symptoms.

Assessing universality of DNA barcoding in geographically isolated selected desert medicinal species of Fabaceae and Poaceae.

In pursuit of developing fast and accurate species-level molecular identification methods, we tested six DNA barcodes, namely ITS2, matK, rbcLa, ITS2+matK, ITS2+rbcLa, matK+rbcLa and ITS2+matK+rbcLa, for their capacity to identify frequently consumed but geographically isolated medicinal species of Fabaceae and Poaceae indigenous to the desert of Cholistan. Data were analysed by BLASTn sequence similarity, pairwise sequence divergence in TAXONDNA, and phylogenetic (neighbour-joining and maximum-likelihood trees) methods. Comparison of six barcode regions showed that ITS2 has the highest number of variable sites (209/360) for tested Fabaceae and (106/365) Poaceae species, the highest species-level identification (40%) in BLASTn procedure, distinct DNA barcoding gap, 100% correct species identification in BM and BCM functions of TAXONDNA, and clear cladding pattern with high nodal support in phylogenetic trees in both families. ITS2+matK+rbcLa followed ITS2 in its species-level identification capacity. The study was concluded with advocating the DNA barcoding as an effective tool for species identification and ITS2 as the best barcode region in identifying medicinal species of Fabaceae and Poaceae. Current research has practical implementation potential in the fields of pharmaco-vigilance, trade of medicinal plants and biodiversity conservation.

Antioxidant potential of some plants of Brassicaceae Burnett and Poaceae Barnhart

Objective – to estimate the antiradical scavenging ability of extracts of some plants of Brassicaceae Burnett and Poaceae Barnhart. species, to evaluate the total antioxidant activity of plants in the conditions of M.M. Gryshko National Botanical Garden of the NAS of Ukraine. Material and methods. Plant material of this investigation – species, varieties and cultivars of Brassicaceaae and Poaceae families: Brassica campestris f. annua D.C. (BCA), B. campestris f. biennis D.C.× B. napus f. biennis D.C., cv. Innovatsiia (BCBNI), B. campestris f. biennis D.C. × B. rapa L. × B. napus f. biennis D.C. (BCBRBN), B. juncea (L.) Czern. (BJ), B. juncea (L.) Czern. f. biennis, cv. Annushka (BJA), B. napus f. biennis D.C., f. EROF-5 (BNE-5), B. rapa L. (BR), B. rapa subsp. rapifera Metzger (BRR), Raphanus sativus L. var. oleiformis Pers. (RSO), Miscanthus sacchariflorus (Maxim.) Benth., cv. Snihopad (MSS), M. sinensis Anderss. f. ESBMK-6 (MSE-6), Panicum virgatum L. f. PB (PVPB), P. virgatum L. f. PL (PVPL), Sorghum bicolor (L.) Moench. f. ETSSDF-11 (SBE-11), S. nigrum Roemer et Schultes f. ETSSCHF-1 (SNE-1), S. saccharatum (L.) Moench. cv. Medove (SSM), S. sudanense (Piper) Stapf (SS), S. technicum (Koern.) Bait. et Trab. (ST). The antioxidant activity of methanol and aqueous extracts based on the discoloration reaction on the solution of DPPH (2,2-diphenyl-1-picrylhydrazyl free radical) was determined according to Brandt-Williams et al. The determination of content of ascorbic acid was conducted according to V.P. Krishchenko, the content of carotene – according to B.P. Pleshkov. Results. The antioxidant activity of methanol extracts of plants of Brassicaceae was registered in the range from 16.94±0.15 (BCA) to 36.91 ± 0.26 (BRR) % and aqueous extracts – from 26.53 ± 0.34 (BJ) to 65.85 ± 0.30 (RSO) %. This parameter for methanol extracts of Poaceae species was in range from 31.13 ± 0.32 (MSE-6) to 86.48 ± 0.49 (SNE-1) % and aqueous extracts – from 33.10 ± 0.47 (ST) to 83.14 ± 0.46 (PVPB) %. It was determined concentration of ascorbic acid from 118.67 ± 9.90 (BJA) to 566.61 ± 38.37 (BNE-5) mg% and carotene – from 0.48 ± 0.01 (BJA) to 3.11 ± 0.07 (BJ) mg% for Brassicaceae plants. Content of ascorbic acid in range from 11.80 ± 0.85 (PVPB) to 77.39 ± 1.29 (SS) mg% and carotene – from 0.05 ± 0.00 (PVPB) to 0.62 ± 0.02 (PVPL) mg% was identified for Poaceae plants. Conclusions. This study showed that plant raw material of investigated plants is a valuable source of antioxidants and vitamins. Methanol and water extracts of plants of Poaceae had higher antiradical activity against DPPH radical than extracts of plants of Brassicaceae. The higher level of ascorbic acid and carotene was observed in extracts of plants of Brassicaceae. The minimal content of ascorbic acid and carotene found for BJA (Brassicaceae) and PVPB (Poaceae).

The effect of technogenic emissions on the heavy metals accumulation by herbaceous plants.

The effect of technogenic emissions on the input of Pb, Zn, Cd, Cu, Mn, Cr, and Ni into plants from the Poaceae and Asteraceae families has been studied. Soil and plant contamination by anthropogenic emissions from industrial enterprises leads the decreasing of crop quality; therefore, the monitoring investigation of plants and soils acquires special importance. The herbaceous plants may be used as bioindicators for main environmental changes. It was found that the high level of anthropogenic load related to atmospheric emissions from the power plant favors the heavy metal (HM) accumulation in herbaceous plants. Contamination with Pb, Cd, Cr, and Ni was revealed in plants growing near the power plant. Heavy metals arrive to plants from the soil in the form of mobile compounds. Plant family is one of the main factors affecting the HM distribution in the above- and underground parts of plants. Plants from the Poaceae family accumulate less chemical elements in their aboveground parts than the Asteraceae plants. Ambrosia artemisiifolia and Artemisia austriaca are HM accumulators. For assessing the stability of plants under contamination with HMs, metal accumulation by plants from soil (the bioconcentration factor) and metal phytoavailability from plants above- and underground parts (the acropetal coefficient) were calculated. According to the bioconcentration factor and translocation factor values, Poaceae species are most resistant to technogenic contamination with HMs. The translocation factor highest values were found for Tanacetum vulgare; the lowest bioconcentration factor values were typical for Poa pratensis.

Evaluation of biological potential of selected species of family Poaceae from Bahawalpur, Pakistan

BackgroundOxidative stress as well as bacterial and fungal infections are common source of diseases while plants are source of medication for curative or protective purposes. Hence, aim of study was to compare the pharmacological potential of seven grass species in two different solvents i.e. ethanol and acetone.MethodsPreliminary phytochemical tests were done and antioxidant activities were evaluated using ELISA and their IC50 values and AAI (%) were recorded. ANOVA was used for statistical analyses. DNA damage protection assay was done using p1391Z plasmid DNA and DNA bands were analyzed. Antimicrobial activity was done via disc diffusion method and MIC and Activity Index were determined. Cytotoxic activity was carried out using the brine shrimps’ assay and LC50 values were calculated using probit analysis program.ResultsPhytochemical studies confirmed the presence of secondary metabolites in most of the plant extracts. Maximum antioxidant potential was revealed in DiAEE, DiAAE (AAI- 54.54% and 43.24%) and DaAEE and DaAAE (AAI- 49.13% and 44.52%). However, PoAEE and PoAAE showed minimum antioxidant potential (AAI- 41.04% and 34.11%). SaSEE, DiAEE and ElIEE showed very little DNA damage protection activity. In antimicrobial assay, DaAEE significantly inhibited the growth of most of the microbial pathogens (nine microbes out of eleven tested microbes) among ethanol extracts while DaAAE and ImCAE showed maximum inhibition (eight microbes out of eleven tested microbes) among acetone plant extracts. However, PoAEE and PoAAE showed least antimicrobial activity. F. oxysporum and A. niger were revealed as the most resistant micro-organisms. ImCEA and ImCAE showed maximum cytotoxic potential (LC50 11.004 ppm and 7.932 ppm) as compared to the other plant extracts.ConclusionFodder grasses also contains a substantial phenols and flavonoids contents along with other secondary metabolites and, hence, possess a significant medicinal value. Ethanol extracts showed more therapeutic potential as compared to the acetone extracts. This study provides experimental evidence that the selected species contains such valuable natural compounds which can be used as medicinal drugs in future.

Anatomical features of three perennial swampy plants of Poaceae, grown on the water stream banks in Nile Delta, Egypt

The anatomical structure of plants is largely varied according to genetics as well as the environmental conditions. The present study aims to describe the anatomical features of three species of family Poaceae growing naturally in canal bank habitat namely: Arundo donax, Pennisetum setaceum and Saccharum spontaneum. These plants are referred as medicinal, grazing or fiber producing plants. Samples were obtained from the canal banks in Nile delta of Egypt. The samples were fixed in formalin-aceto-alcohol and cross sections were prepared, examined using full automatic Olympus microscope and photographed at different power. In the present study, regarding leaves, the general appearance of the leaves sections showed either flat or V-shaped blade. The leaf blades of the three plants show a typical monocot organization. The mesophyll cells showed no distinct differentiation into palisade or spongy tissue. In P. setaceum and S. spontaneum, the leaves have distinct bulliform cells which enable the leaf to fold or roll. The vascular bundles of leaves are collateral, closed, numerous and diffuse in distribution. The vascular bundles are larger in size and surrounded by a sheath of fibers. However, the cross-section of the stem is more or less circular. Ground tissue is parenchymatous and not differentiated into cortex and pith in P. setaceum and S. spontaneum, while A. donax has large hollow pith. The bundles are collateral and are usually surrounded by a sclerenchymatous sheath.

Comparing seeds germination of some local plant species on two hydroseeding mulches for post mining revegetation

The aims of this study were to determine seed germination rate of some local plant species in two hydroseeding mulches containing different tackifier concentration, as well as to determine the optimal hydroseeding mulch media composition for germinating seeds. This study used seeds of 13 local plant species: two species of Cyperaceae ( Cyperus brevifolius , C. javanicus ), five species of Leguminosae ( Cajanus cajan, Crotalaria pallida, Sesbania grandiflora, S. sesban, Tephrosia purpurea ), and six species of Poaceae ( Eleusine indica, Paspalum conjugatum, Sorghum timorense , S. bicolor , Sporobolus indicus, Themeda arundinaceae ) . Two hydroseeding mulch media with different tackifier composition were mixed with seeds of each species and then sowed in pots. Each treatment was repeated three times. Moistened cotton wool was used as control and comparative media for observing seed viability. Seed germination in mulch media was observed during 13 days. The results showed that only 8 of 13 species could be germinated: S. indicus, S. timorense , T. arundinaceae, C. cajan, C. pallida, S. grandiflora, S. sesban, and T. purpurea. The highest germination rate was shown by S. sesban (67%) in M 2 medium and the lowest one was shown by T. arundinaceae (2%) in both media. The fastest germination time was recorded for C. pallida and S. sesban seeds that germinated in 2 days after sowing (DAS) in both media, while S. timorense and T. arundinaceae seeds showed the lowest ones in 11 DAS. The fluid M 1 medium was optimal for seeds germination of S. sesban (50%) and S. grandiflora (35%), while the thicker M 2 medium was optimal for seeds germination of S. sesban (67%) and S. timorense (50%) in 13 DAS. The maximum germination rate was generally reached in 11 DAS.

An Ancient Integration in a Plant NLR is Maintained as a Trans-species Polymorphism

The origin of genetic diversity in a species is a product of novel mutation and alleles maintained during speciation. Identification of alleles that are derived from a common ancestor is critical for understanding the selective processes experienced during speciation events. Here, we report on the inter- and intra-specific diversity of plant immune receptors in the Mla locus across Poaceae species. These immune receptors belong to the class of cytoplasmic-nuclear localized nucleotide-binding leucine-rich repeat (NLR) proteins. Plant immune receptors are under constant selective pressure to maintain resistance to plant pathogens, and novel mutations leading to improved immune responses are selected. We discovered a fusion of the plant immune receptor RGH2 with a component of the exocyst complex (Exo70). Phylogenetic analysis of Exo70 gene families from Poaceae species found that the integrated Exo70 was derived from Exo70F1. To identify the origin of this gene fusion, we assembled leaf transcriptomes from diverse Poaceae species. Inter-specific conservation in the RGH2- Exo70F1 gene fusion was found in several Pooideae species, whereas Brachypodium distachyon RGH2 is fused to a receptor-like kinase. To establish the time of gene fusion, we performed phylogenetic analysis using non-integrated and integrated Exo70F1. We found a diphyletic tree composed of non-integrated Exo70F1 and integrated Exo70F1, with Exo70F1 from B. distachyon and B. stacei forming an outgroup. This indicates that a single gene fusion event occurred after the speciation of Brachypodieae, but prior to Poeae-Triticeae radiation. These results, coupled with the observation of inter- and intra-specific variation in RGH2, demonstrate the maintenance of RGH2-Exo70F1 as a trans-species polymorphism over 24 My.

Getting the dietary knowledge to restore a missing species: seasonal diet of Atlas deer Cervus elaphus barbarus in Tazekka National Park, Morocco

Atlas deer Cervus elaphus barbarus was reintroduced in Tazekka National Park in 1994 to help restore the natural state in the regions of the Middle Atlas and Rif mountains. A study of its diet in this area was recommended by the National Strategy for ungulates in order to get data to assess the feasibility of a subsequent release. So our aim was to study the diet of Atlas deer and its seasonal variation. Faeces were collected in Atlas during 2013–2014 in Bab Klati 520‐ha reserve located in the west of the Tazekka National Park. Faecal samples were micro‐histologically analysed based on a reference epidermis catalogue of all existing plants in the reserve. Poaceae species, the main representatives of the herbaceous category, were consumed at 28%, 37% and 43% of the diet in autumn, winter and spring, respectively. In summer, the consumption of Poaceae did not exceed 2%, presumably because of their limited availability. Pteridium aqualinium was consumed especially in summer (6%). Shrubs were represented by three main species: Ulex boivinii, Cytisus triflorus and Lavandula steochas. Consumption of U. boivinii was high in autumn (41%) and spring (31%) and low in winter (16%) and summer (6%). As for C. triflorus, the consumption was maximal in winter (30%), average in autumn (19%) and spring (18%) and lowest in summer (2%). Lavandula steochas was consumed mainly in autumn (8%). In the summer, trees were the main components of the diet and were represented by the oak species Quercus faginea (61%), Q. rotundifolia (13%) and Q. suber (5%). Our analysis revealed dramatic changes in the diet of Atlas deer in Morocco from one season to the other, indicating that this animal is able to change its foraging strategy based on its needs, and on the changing availability of various plants in the environment.

Selection of Expression Reference Genes with Demonstrated Stability in Barley among a Diverse Set of Tissues and Cultivars

ABSTRACTReference genes are selected based on the assumption of temporal and spatial expression stability and on their widespread use in model species. They are often used without validation in the studied species. For barley (Hordeum vulgare L.), previous reference gene validation studies have been limited by the number of tissues, cultivars, and/or reference gene candidates assayed. Publically available bioinformatic resources are now available that enable efficient assessment of much larger numbers of candidate genes than is possible with empirical approaches. Expression sequence tag profile viewer data from the UniGene library were used to predict the expression stability of 655 barley genes. The expression profiles of 20 gene candidates predicted to be stable across tissue types were evaluated in eight tissues of the cultivar ‘Conlon’ by real‐time quantitative polymerase chain reaction. The five most stable genes were then tested in the barley cultivars ‘Golden Promise’ and ‘Harrington’ and (to test potential applicability to other Poaceae species) in the oat (Avena sativa L.) cultivar ‘Hifi’. The traditional reference gene actin and the candidate genes elongation factor EF‐2 and malate dehydrogenase demonstrated the most stable expression. The predictive capacity of bioinformatics to identify suitable reference genes was demonstrated. Four genes with better stability than all except one traditionally used reference gene were discovered.

Анатомические особенности эпидермы листа и формирование фитолитов некоторых представителей Poaceae юга Западной Сибири

The article analyzed main phytolith morphotypes produced and anatomical microscopic structure of grass leaf epidermis in dominant species in the south of West Siberia. Phytoliths are silica microfossils formed inside plant cells that allow identification of plants in paleobotanical studies. The choice of objects in the study was based on presence of strong silicification in selected dominant grasses. For the first time in our region, phytolith assemblage from a plant (% of morphotypes) was compared to the anatomical structure of leaf epidermis in Poaceae. We studied seven Poaceae species that together produced all major morphotypes found in soils of the region: Achnatherum sibiricum, Agrostis gigantea, Elymus dahuricus, Festuca pseudovina, Festuca pratensis, Koeleria cristata, Phalaroides arundinacea. Because all of these species were regionally important dominants, their phytoliths would help diagnose specific plant communities. We showed localization of main phytoliths in the leaves of these species and compared short cell and trichome distribution in a plant with its silicification. The results allowed to better visualize 3D shapes of epidermal cells. Most common phytoliths were formed as cell wall casts that repeat the shape of the cell in question.Some short cells, for example rondels and bilobates, did not match the shape of the cell, indicating active shaping process present inside the cells. An interesting result was a lack of silicification of trichomes in some grasses despite heavy trichome presence. This study will help researchers to avoid mistakes in identifying common dominant plantsbased on their phytolith record in paleosediments, within West Siberia and across all of Northern Eurasia.&nbsp

New taxa in Agrostis, Bromopsis, Koeleria and Poa (Poaceae) from the Russian Far East

Five new species of the family Poaceae are described from the Russian Far East: Agrostis czernjaginae Prob. (sect. Trichodium) (revealed chromosome number 2n = 42) from thermal springs of Kamchatka, Bromopsis kozhevnikovii Prob. (sect. Rhizomatosae) from high mountains of Dusse-Alin Range in the Khabarovsk Territory, Poa amurica Prob. (sect. Stenopoa) from Selemdzha River in the Amur Region, Koeleria dersu Prob. et Prokopenko (sect. Koeleria) from the eastern macroslope of Sikhote-Alin in the Primorye Territory, Agrostis × lapenkoi Prob. (probably, intersectional hybrid: A. giganteaRoth × A. clavata Trin.) from Ussuri River basin, also in the Primorye Territory.

Functional implications of root cortical senescence for soil resource capture

Root phenes play a primary role in plant adaptation to edaphic stress. Understanding the functional implications of root phenotypes will enable the development of crop varieties with improved soil resource acquisition. Root cortical senescence (RCS) is a type of programmed cell death in cortical cells of several Poaceae species. Until recently there has been very little attention to the functional implications of RCS for water and nutrient capture. We explore the functional implications of RCS as an adaptive trait for water and nutrient acquisition. The present review summarizes evidence from our own studies and other published work, and provides novel insights into the fitness landscape of RCS. Progress has recently been achieved in understanding the development and physiological implications of RCS. We propose that RCS is a useful trait for water and nutrient acquisition, particularly in edaphic stress conditions. Further research is needed to understand the utility and tradeoffs of RCS in the context of specific environments, management practices, and phenotypic backgrounds. The utility of RCS for improved plant performance under edaphic stress merits investigation in the field. RCS may be a useful breeding target for improved soil resource capture in several major crop species including wheat, barley, and triticale.

Copper, Manganese and Zinc Bioaccumulation in Some Common Poaceae Species Along Romanian Black Sea Coast

Copper, manganese and zinc bioaccumulation potential was screened for three common Poaceae species, Hordeum murinum ssp. murinum L., Leymus racemosus ssp. sabulosus (M. Bieb.) Tzvelev and Lollium perenne L., abundantly growing along the Romanian Black Sea Coastal area, Constanta County. The concentration of the selected heavy metals was analyzed though atomic absorption spectrometry in samples of aboveground plant organs and soils. To assess the potential for phytoaccumulation, the Biological Accumulation Coefficients (BAC) were calculated. Considering the minimal thresholds widely accepted in literature for Cu, Mn and Zn hyperaccumulators, none of the selected species can fit in this category. The highest average copper concentration was found in Hordeum murinum ssp. murinum L. (5.45 mg/kg). For manganese, the highest value was found in Lollium perenne L. (104.08 mg/kg), while for zinc, the maximum was reached in Leymus racemosus ssp. sabulosus (M. Bieb.) Tzvelev, tissue (62.95 mg/kg). BAC values showed that all species are manganese excluders, with a remarkable maximum value of 0.55 in Lollium perenne. L. All species had average BAC above 1 for Cu and Zn, with a maximum in Leymus racemosus ssp. sabulosus (M. Bieb.) Tzvelev (4.85 and 2.98, respectively). However, there was a significant variation among individuals, usually, a high metal content in plant tissue being associated with low metal concentration in soil. The exception was Lollium perenne L., with BAC constantly above 1 (average BAC of 2.27 for Cu and 1.69 for Zn). These results emphasize a significant potential for phytostabilization of copper- and zinc-rich soils and open the way for heavy metals phytoextraction capacity studies of the Poaceae species along Romanian littoral.

Diversity and community composition of herbaceous plants in different habitat types in south‐east Cameroon

AbstractThe composition of herbaceous vegetation was evaluated with the aim of characterizing forests at various ages of stand development. Herb stems were sampled in 250 4‐m² square plots distributed within six habitat types. A total of 36 herb species belonging to 15 families were recorded. Species richness did not significantly differ between habitat types. Most herb species occurred in all habitat types and were therefore generalists. However, a few indicator herb species were detected, and the results roughly suggested that herb species of the families Poaceae and Araceae were indicative of late successional forests; Zingiberaceae are indicative of early successional forests; and Commelinaceae, Costaceae, Cyperaceae and Marantaceae are indicators of flooded habitats. Species diversity and stem density of herbaceous plants did not change with forest succession as a decrease in abundance and frequency of occurrence of pioneer species in late successional forests was counterbalanced by the presence of generalist and late successional species. However, increasing proportions of dwarf stems in late successional forests translated to changes in the vertical structure of herbaceous plant communities. Herbivory pressure by gorillas did not have a notable effect on herbaceous plant community development. This study contributes to the definition of herbaceous ecological indicators of forest succession in different settings.

Evolutionary modes of emergence of short interspersed nuclear element (SINE) families in grasses.

Short interspersed nuclear elements (SINEs) are non-autonomous transposable elements which are propagated by retrotransposition and constitute an inherent part of the genome of most eukaryotic species. Knowledge of heterogeneous and highly abundant SINEs is crucial for de novo (or improvement of) annotation of whole genome sequences. We scanned Poaceae genome sequences of six important cereals (Oryza sativa, Triticum aestivum, Hordeum vulgare, Panicum virgatum, Sorghum bicolor, Zea mays) and Brachypodium distachyon to examine the diversity and evolution of SINE populations. We comparatively analyzed the structural features, distribution, evolutionary relation and abundance of 32 SINE families and subfamilies within grasses, comprising 11052 individual copies. The investigation of activity profiles within the Poaceae provides insights into their species-specific diversification and amplification. We found that Poaceae SINEs (PoaS) fall into two length categories: simple SINEs of up to 180bp and dimeric SINEs larger than 240bp. Detailed analysis at the nucleotide level revealed that multimerization of related and unrelated SINE copies is an important evolutionary mechanism of SINE formation. We conclude that PoaS families diversify by massive reshuffling between SINE families, likely caused by insertion of truncated copies, and provide a model for this evolutionary scenario. Twenty-eight of 32 PoaS families and subfamilies show significant conservation, in particular either in the 5' or 3' regions, across Poaceae species and share large sequence stretches with one or more other PoaS families.

Spatio-temporal flowering patterns in Mediterranean Poaceae. A community study in SW Spain.

This study focused on phenological timing and spatial patterns in 30 Poaceae species flowering in spring in different types of plant cover (scrub, riverbank and pasture). Grass community composition was studied, and the influence of species and plant cover on the start date and duration of flowering was assessed from March to June in both 2014 and 2015. Twenty-nine sampling sites were selected for phenological monitoring using the BBCH scale. Data were subjected to GLMM analyses. Binary discriminant analysis revealed differences in grass community composition as a function of plant cover type; scrub cover comprised a considerably larger number of species than those in riverbank and pasture. Moreover, more species diversity was observed in 2014 than in 2015 with a drier and stressed pre-flowering period. Differences on phenology were also recorded between plant cover types and study years. Species in pasture and riverbank flowered before (113.4days; 116.1days) than species in scrub (120.9days), being these species with shorter flowering length because they are more exposed to the characteristic of the Mediterranean region during the summer. In general, flowering onset occurred later in 2014 (118.2days) than in 2015 (115.8days), probably attributable to precipitation occurring during March. On the other hand, spatial autocorrelation within some cover types has been observed, showing spatial patterns exist at a smaller scale. The findings of this study contribute to a better understanding of grass phenology in different environments.

Evaluating sampling strategy for DNA barcoding study of coastal and inland halo-tolerant Poaceae and Chenopodiaceae: A case study for increased sample size.

Environmental conditions in coastal salt marsh habitats have led to the development of specialist genetic adaptations. We evaluated six DNA barcode loci of the 53 species of Poaceae and 15 species of Chenopodiaceae from China's coastal salt marsh area and inland area. Our results indicate that the optimum DNA barcode was ITS for coastal salt-tolerant Poaceae and matK for the Chenopodiaceae. Sampling strategies for ten common species of Poaceae and Chenopodiaceae were analyzed according to optimum barcode. We found that by increasing the number of samples collected from the coastal salt marsh area on the basis of inland samples, the number of haplotypes of Arundinella hirta, Digitaria ciliaris, Eleusine indica, Imperata cylindrica, Setaria viridis, and Chenopodium glaucum increased, with a principal coordinate plot clearly showing increased distribution points. The results of a Mann-Whitney test showed that for Digitaria ciliaris, Eleusine indica, Imperata cylindrica, and Setaria viridis, the distribution of intraspecific genetic distances was significantly different when samples from the coastal salt marsh area were included (P < 0.01). These results suggest that increasing the sample size in specialist habitats can improve measurements of intraspecific genetic diversity, and will have a positive effect on the application of the DNA barcodes in widely distributed species. The results of random sampling showed that when sample size reached 11 for Chloris virgata, Chenopodium glaucum, and Dysphania ambrosioides, 13 for Setaria viridis, and 15 for Eleusine indica, Imperata cylindrica and Chenopodium album, average intraspecific distance tended to reach stability. These results indicate that the sample size for DNA barcode of globally distributed species should be increased to 11–15.