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Sample records for grass pennisetum clandestinum

  1. Enhancing Phytoremediation Potential of Pennisetum clandestinum Hochst in Cadmium-Contaminated Soil Using Smoke-Water and Smoke-Isolated Karrikinolide.

    PubMed

    Okem, Ambrose; Kulkarni, Manoj G; Van Staden, Johannes

    2015-01-01

    The use of plant growth regulators (PGRs) and biostimulants to enhance phytoextraction is gaining popularity in phytoremediation technology. This study investigated the stimulatory effects of smoke-water (SW), a smoke-derived compound karrikinolide (KAR1) and other known plant growth regulators (PGRs) [gibberellic acid (GA3), kinetin (Kin) and indole-3-butyric acid (IBA)] to enhance the phytoextraction potential of Pennisetum clandestinum. Pennisetum clandestinum seedlings were grown for 10 weeks in vermiculite using Hoagland's nutrient solution and were treated with cadmium (Cd) (2, 5, and 10 mg L(-1)) and SW, KAR1 and PGRs. KAR1 exhibited positive effects on shoot and root dry weight (140 and 137 mg respectively) at the highest concentration of Cd (10 mg L(-1)) compared to all the other treatments. KAR1 and SW treatments used in the present study significantly improved the phytoextraction potential of P. clandestinum (602 and 575 mg kg(-1) respectively) compared to the other tested PGRs. This is the first report on the use of SW and KAR1 to enhance phytoremediation potential in P. clandestinum. Further studies are needed to elucidate the exact mechanisms of smoke constituents involved in phytoextraction potential of plant species.

  2. Contrasting genetic structure between Magnaporthe grisea populations associated with the golf course turfgrasses Lolium perenne (perennial ryegrass) and Pennisetum clandestinum (kikuyugrass).

    PubMed

    Douhan, Greg W; de la Cerda, Karla A; Huryn, Karyn L; Greer, Christopher A; Wong, Francis P

    2011-01-01

    Gray leaf spot (GLS) disease of perennial ryegrass (Lolium perenne) and kikuyugrass (Pennisetum clandestinum) in golf courses in California was first noted in 2001 and 2003, respectively, and within 5 years had become well established. The causal agent of the disease is the fungus Magnaporthe grisea, which is known to consist primarily of clonal lineages that are highly host specific. Therefore, our objective was to investigate host specificity and population dynamics among isolates associated primarily from perennial ryegrass and kikuyugrass since the disease emerged at similar times in California. We also obtained isolates from additional hosts (tall fescue, St. Augustinegrass, weeping lovegrass, and rice) and from the eastern United States for comparative purposes. A total of 38 polymorphic amplified fragment length polymorphism makers were scored from 450 isolates which clustered by host with high bootstrap support (71 to 100%). Genetic structure between kikuyugrass and perennial ryegrass isolates differed significantly. Isolates from kikuyugrass were genotypically diverse (n = 34), possessed both mating types, and some tests for random mating could not be rejected, whereas isolates from perennial ryegrass were less genotypically diverse (n = 10) and only consisted of a single mating type. Low genotypic diversity was also found among the other host specific isolates which also only consisted of a single mating type. This is the first study to document evidence for the potential of sexual reproduction to occur in M. grisea isolates not associated with rice (Oryza sativa). Moreover, given the significant host specificity and contrasting genetic structures between turfgrass-associated isolates, the recent emergence of GLS on various grass hosts in California suggests that potential cultural practices or environmental changes have become conducive for the disease and that the primary inoculum may have already been present in the state, despite the fact that two

  3. The utilization of Vallisneria aethiopica, Brassica oleracea and Pennisetum clandestinum by Tilapia rendalli

    NASA Astrophysics Data System (ADS)

    Hlophe, S. N.; Moyo, N. A. G.

    A common lawn grass; kikuyu grass, an abundant vegetable; cabbage and vallisneria a common macrophyte were tested for utilisation by two size classes of a herbivorous fish, Tilapia rendalli held in glass aquarium tanks. The test feeds were given to sub-adult T. rendalli for 133 days at 8% body weight and juvenile fish for 84 days at 15% body weight. Sub-adult and juvenile fish fed kikuyu grass attained a higher specific growth rate, higher protein efficiency ratio and better food conversion ratio than those fed cabbage and vallisneria. This is explained by the differences in the protein content, higher levels of lysine and the sulphur-containing amino acid, methionine in kikuyu grass. Palatability studies of the juveniles also showed that kikuyu was most preferred. However, sub-adults preferred vallisneria, kikuyu and cabbage respectively. The possible reasons for the selection are discussed.

  4. Cadmium accumulation in deer tongue grass (Panicum clandestinum L.) and potential for trophic transfer to microtine rodents.

    PubMed

    Sankaran, Renuka P; Ebbs, Stephen D

    2007-07-01

    Site 36 at the Crab Orchard National Wildlife Refuge includes a Cd-contaminated soil dominated by deer tongue grass (Panicum clandestinum L.). Analysis of deer tongue grass from this site indicated that biomass and leaf surface area were reduced and that there was a linear relationship between both plant bioavailable soil Cd and total soil Zn and tissue Cd concentration. The Cd concentrations in stems and leaves were also used to estimate the dietary Cd exposures that might be experienced by prairie voles (Microtus ochrogaster) and pine voles (M. pinetorum) consuming deer tongue grass. Renal and hepatic Cd burdens predicted from exclusive consumption of deer tongue grass would be comparable to those that have resulted in chronic toxicity in rodents. The results suggest that for the contaminated soil at Site 36, conditions could allow for the accumulation of Cd in deer tongue grass to concentrations that may pose an ecological risk.

  5. Ecophysiology of the invader Pennisetum setaceum and three native grasses in the Canary Islands

    NASA Astrophysics Data System (ADS)

    González-Rodríguez, Agueda M. a.; Baruch, Zdravko; Palomo, Debora; Cruz-Trujillo, Gilberto; Jiménez, M. a. Soledad; Morales, Domingo

    2010-03-01

    Pennisetum setaceum (fountain grass) is an aggressive invader in the arid and semi-arid habitats of the tropics and subtropics. In the last twenty years the spread of fountain grass in the Canary Islands has been very rapid. We compared its ecophysiological, architectural and reproductive traits with those of three native grasses ( Hyparrhenia hirta, Cenchrus ciliaris and Aristida adscensionis) in two habitats of Tenerife Island which differ in rainfall. The detection of traits that differ between native and invader grasses may provide information for the improved control and eradication of the latter contributing to protect the native plant diversity. P. setaceum and the native grasses differed in all measured traits and in their response to water availability which is more restricted in the southern site. Specific leaf area was lower in P. setaceum than in the native grasses. Although this reduces carbon assimilation per unit area, it also reduces transpiration, increasing water use efficiency and contributes to the maintenance of high relative water content. Leaf N in P. setaceum was lower than in the native grasses indicating higher nitrogen use efficiency. The activity of photosystem II was higher and lasted longer in P. setaceum than in the native grasses. The ecophysiological traits of P. setaceum support its large size, extensive canopy and shorter leaf senescence period. They confer considerable competitive advantage to the invader and partially explain its success in the Canary Islands. The differences between the invader and the native grasses were maintained in both sites revealing a good adaptation of P. setaceum to the low resource local habitats in the Canary Islands and confirms its large plasticity. The large invasive potential of P. setaceum, in concert with the projected global changes, forecast eventual risks for the conservation of the endemic flora and remaining native communities in the Canary Islands.

  6. Seedling growth of a native (Ampelodesmos mauritanicus) and an exotic (Pennisetum setaceum) grass

    NASA Astrophysics Data System (ADS)

    Badalamenti, Emilio; Militello, Marcello; La Mantia, Tommaso; Gugliuzza, Giovanni

    2016-11-01

    Scarce information is available on the biological reasons why a small subset of introduced species can effectively establish within novel ecosystems. A comparison of early growth traits can help to explain the better performance of alien invasive species versus native co-occurring species. In one year-long experiment, we compared the early life stages of Ampelodesmos mauritanicus (Poir.) Dur. & Schinz (Amp), a native perennial Mediterranean grass, and Pennisetum setaceum (Forssk.) Chiov (Penn), an emerging invader grass in sub-arid and Mediterranean-climate areas. The Penn seedlings grew significantly faster and were approximately 2.5 times taller than the Amp seedlings, reaching a final average height of 90 cm. The shoot and root dry masses of the Penn seedlings were, respectively, more than 14 times and 4 times higher than those of the Amp seedlings. As a consequence, the shoot:root ratio was significantly higher in Penn, which resulted in a greater allocation of resources to the photosynthetic organs. Penn showed a more rapid life cycle compared with Amp. Penn produced seeds 9 months after sowing while no spikelet was produced by Amp until the end of the experiment. As a consequence, Penn may gain a reproductive advantage due to rapid seed dissemination. Ultimately, a suite of peculiar early growth traits makes Penn an aggressive competitor against Amp, which is an important floristic element of native Mediterranean grasslands. Penn seems better suited than Amp in colonizing frequently disturbed sites with fluctuating resource availability or irregular rainfall distribution and Penn is gradually replacing Amp.

  7. Optimization of delignification of two Pennisetum grass species by NaOH pretreatment using Taguchi and ANN statistical approach.

    PubMed

    Mohaptra, Sonali; Dash, Preeti Krishna; Behera, Sudhanshu Shekar; Thatoi, Hrudayanath

    2016-01-01

    In the bioconversion of lignocelluloses for bioethanol, pretreatment seems to be the most important step which improves the elimination of the lignin and hemicelluloses content, exposing cellulose to further hydrolysis. The present study discusses the application of dynamic statistical techniques like the Taguchi method and artificial neural network (ANN) in the optimization of pretreatment of lignocellulosic biomasses such as Hybrid Napier grass (HNG) (Pennisetum purpureum) and Denanath grass (DG) (Pennisetum pedicellatum), using alkali sodium hydroxide. This study analysed and determined a parameter combination with a low number of experiments by using the Taguchi method in which both the substrates can be efficiently pretreated. The optimized parameters obtained from the L16 orthogonal array are soaking time (18 and 26 h), temperature (60°C and 55°C), and alkali concentration (1%) for HNG and DG, respectively. High performance liquid chromatography analysis of the optimized pretreated grass varieties confirmed the presence of glucan (47.94% and 46.50%), xylan (9.35% and 7.95%), arabinan (2.15% and 2.2%), and galactan/mannan (1.44% and 1.52%) for HNG and DG, respectively. Physicochemical characterization studies of native and alkali-pretreated grasses were carried out by scanning electron microscopy and Fourier transformation Infrared spectroscopy which revealed some morphological differences between the native and optimized pretreated samples. Model validation by ANN showed a good agreement between experimental results and the predicted responses.

  8. Physiological and Morphological Effects of High Water Tables on Early Growth of Giant Reed (Arundo donax), Elephant Grass (Pennisetum purpureum), Energycane and Sugarcane (Saccharum spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing demand for renewable energy sources has led to interest in high-biomass crops. Species that have been proposed as well-suited for biofuel production in the Everglades Agricultural Area (EAA) of Florida include Giant Reed (Arundo donax), Elephant Grass (Pennisetum purpureum), Energycane (S...

  9. Copper tolerance of the biomass crops Elephant grass (Pennisetum purpureum Schumach), Vetiver grass (Vetiveria zizanioides) and the upland reed (Phragmites australis) in soil culture.

    PubMed

    Liu, Xinghua; Shen, Yixing; Lou, Laiqing; Ding, Chenglong; Cai, Qingsheng

    2009-01-01

    Pot trials were conducted to study the influence of copper (Cu) on the growth and biomass of Elephant grass (EG, Pennisetum purpureum Schumach), Vetiver grass (VG, Vetiveria zizanioides) and the upland reed (UR, Phragmites australis). Cu toxicity in EG, VG and UR was positively correlated with the total and bioavailable Cu concentrations in the soil. Based on the EC50, dry weights, Cu contents, chlorophyll contents and photosynthesis rates, the Cu tolerance of the three species followed the trend EGNVGNUR. There were no significant differences in the unit calorific values among the different plants, though the total calorific values of EG were higher than those of VG and UR due to its higher biomass. The addition of KH2PO4 to the soil decreased the bioavailability of Cu and the Cu uptake by plants. EG could therefore be a good candidate for growth on Cu-contaminated soils, especially those improved by phosphate.

  10. Ethanol production from sugars obtained during enzymatic hydrolysis of elephant grass (Pennisetum purpureum, Schum.) pretreated by steam explosion.

    PubMed

    Scholl, Angélica Luisi; Menegol, Daiane; Pitarelo, Ana Paula; Fontana, Roselei Claudete; Zandoná Filho, Arion; Ramos, Luiz Pereira; Dillon, Aldo José Pinheiro; Camassola, Marli

    2015-09-01

    In this work, steam explosion was used a pretreatment method to improve the conversion of elephant grass (Pennisetum purpureum) to cellulosic ethanol. This way, enzymatic hydrolysis of vaccum-drained and water-washed steam-treated substrates was carried out with Penicillium echinulatum enzymes while Saccharomyces cerevisiae CAT-1 was used for fermentation. After 48 h of hydrolysis, the highest yield of reducing sugars was obtained from vaccum-drained steam-treated substrates that were produced after 10 min at 200 °C (863.42 ± 62.52 mg/g). However, the highest glucose yield was derived from water-washed steam-treated substrates that were produced after 10 min at 190 °C (248.34 ± 6.27 mg/g) and 200 °C (246.00 ± 9.60 mg/g). Nevertheless, the highest ethanol production was obtained from water-washed steam-treated substrates that were produced after 6 min at 200 °C. These data revealed that water washing is a critical step for ethanol production from steam-treated elephant grass and that pretreatment generates a great deal of water soluble inhibitory compounds for hydrolysis and fermentation, which were partly characterized as part of this study.

  11. Structural changes and enzymatic response of Napier grass (Pennisetum purpureum) stem induced by alkaline pretreatment.

    PubMed

    Phitsuwan, Paripok; Sakka, Kazuo; Ratanakhanokchai, Khanok

    2016-10-01

    Napier grass is a promising energy crop in the tropical region. Feasible alkaline pretreatment technologies, including NaOH, Ca(OH)2, NH3, and alkaline H2O2 (aH2O2), were used to delignify lignocellulose with the aim of improving glucose recovery from Napier grass stem cellulose via enzymatic saccharification. The influences of the pretreatments on structural alterations were examined using SEM, FTIR, XRD, and TGA, and the relationships between these changes and the enzymatic digestibility of cellulose were addressed. The extensive removal of lignin (84%) in NaOH-pretreated fibre agreed well with the high glucan conversion rate (94%) by enzymatic hydrolysis, while the conversion rates for fibre pretreated with Ca(OH)2, NH3, and aH2O2 approached 60%, 51%, and 42%, respectively. The substantial solubilisation of lignin created porosity, allowing increased cellulose accessibility to cellulases in NaOH-pretreated fibre. In contrast, high lignin content, lignin redeposition on the surface, and residual internal lignin and hemicellulose impeded enzymatic performance in Ca(OH)2-, NH3-, and aH2O2-pretreated fibres, respectively.

  12. Effects of Introduced Grasses, Grazing and Fire on Regional Biogeochemistry in Hawaii

    NASA Astrophysics Data System (ADS)

    Elmore, A. J.; Asner, G. P.

    2003-12-01

    African grasses introduced for grazing have expanded in geographic extent in mesic tropical systems of Hawaii and other regions of the world. Grassland expansion leads to increases in fire frequency, speeding woodland and forest destruction at greater geographic scales than occurs with grazing alone. At Pu'uwa'awa'a Ranch, Hawaii, restoration of the native woodland habitat has become a critical objective following the introduction and dominance of the African grass species Pennisetum clandestinum and P. setaceum. Grazing and grass-fueled fires have destroyed over 60% of the original forest. To stabilize these communities, managers must balance the combined effects of grazing and fire. Grazing reduces the recruitment success of native tropical trees, but grazing also reduces fire risk by moderating grass fuel conditions and restricting the extent and density of the most flammable grass species. Our study focuses on two questions: (1) What grazing intensity is necessary to change the fire conditions of a region given in situ soil and precipitation conditions? (2) Have long-term grazing conditions altered soil carbon and nitrogen stocks? We used high resolution imaging spectrometer data to measure photosynthetic and non-photosynthetic vegetation cover, analysis of soil carbon and nitrogen stocks, and measurements of plant community composition along gradients in grazing intensity. P. setaceum, the more flammable alien grass, was dominant where grazing intensity was low and at lower elevations where precipitation is low. The less flammable grass, P. clandestinum, occurred in regions of high grazing intensity and higher precipitation. Grazing influenced the dominance of P. setaceum and P. clandestinum only where precipitation and soil characteristics were suitable for both grasses to occur. At suitable sites, grazing reduced fire conditions through a species sift towards P. clandestinum. Soil carbon and nitrogen stocks decreased with grazing intensity, which was

  13. Thermal conversion of elephant grass (Pennisetum purpureum Schum) to bio-gas, bio-oil and charcoal.

    PubMed

    Strezov, Vladimir; Evans, Tim J; Hayman, Chris

    2008-11-01

    Elephant grass is an abundant, fast growing plant with significant potential as a renewable energy source and for conversion to higher calorific value fuels. This work investigates thermal conversion of elephant grass to bio-gas, bio-oil and charcoal under two heating rates of 10 and 50 degrees C/min. The energy required to pyrolyse elephant grass was evaluated using computer aided thermal analysis technique, while composition of the resultant bio-gas and bio-oil products were monitored with gas chromatographic and mass spectroscopic techniques. At 500 degrees C, the bio-gas compounds consisted primarily of CO2 and CO with small amounts of methane and higher hydrocarbon compounds. The heat of combustion of the bio-gas compounds was estimated to be 3.7-7.4 times higher than the heat required to pyrolyse elephant grass under both heating rates, which confirms that the pyrolysis process can be self-maintained. Faster heating rate was found to increase the amount of liquid products by 10%, while charcoal yields remained almost the same at 30%. The bio-oil mainly consisted of organic acids, phthalate esters, benzene compounds and amides. The amount of organic acids and benzene compounds were significantly reduced at 50 degrees C/min, while the yields of phthalate esters and naphthalene compounds increased. The difference in bio-oil composition with increased heating rate is believed to be associated with the reduction of the secondary reactions of pyrolysis, which are more pronounced under lower heating rate.

  14. Reproductive Response of Ewes Fed with Taiwan Grass Hay (Pennisetum purpureum Schum.) Supplemented with Duckweed (Lemna sp. and Spirodela sp.).

    PubMed

    Zetina-Córdoba, P; Ortega-Cerrilla, M E; Sánchez Torres-Esqueda, M T; Herrera-Haro, J G; Ortega-Jiménez, E; Reta-Mendiola, J L; Vilaboa-Arroniz, J

    2012-08-01

    The effect of duckweed (DW) supplementation was evaluated on dry matter intake (DMI), presence and duration of estrus, percentage of ewes repeating estrus and pregnancy rate, as well as the concentration of progesterone (P4) in multiparous crossbred ewes from Pelibuey, Dorper, and Katahdin breeds, fed with Taiwan grass hay (TWH). Eighteen ewes with 39.7±4 kg mean body weight, kept in individual pens, were randomly assigned to one of the following treatments: T1: TWH, T2: TWH plus 200 g DW, T3: TWH plus 300 g DW. The ewes were synchronized with 40 mg fluorogestone acetate (FGA) and 400 UI equine chorionic gonadotropin (eCG). Data were analyzed as a completely randomized design using the GLM procedure. DW supplementation had no effect on dry matter intake (p>0.05); however, a slight decrease of TWH intake was observed as DW supplementation increased. No differences (p>0.05) were found in the beginning of estrus, percentage of ewes presenting it, its duration, or pregnancy rate. There were no differences (p>0.05) on P4 concentration among treatments, or treatmentxperiod interaction (p>0.05). However the period was significant (p<0.01), since the P4 levels increased as time increased after the removal of the FGA device and eCG application.

  15. Reproductive Response of Ewes Fed with Taiwan Grass Hay (Pennisetum purpureum Schum.) Supplemented with Duckweed (Lemna sp. and Spirodela sp.)

    PubMed Central

    Zetina-Córdoba, P.; Ortega-Cerrilla, M. E.; Sánchez Torres-Esqueda, M. T.; Herrera-Haro, J. G.; Ortega-Jiménez, E.; Reta-Mendiola, J. L.; Vilaboa-Arroniz, J.

    2012-01-01

    The effect of duckweed (DW) supplementation was evaluated on dry matter intake (DMI), presence and duration of estrus, percentage of ewes repeating estrus and pregnancy rate, as well as the concentration of progesterone (P4) in multiparous crossbred ewes from Pelibuey, Dorper, and Katahdin breeds, fed with Taiwan grass hay (TWH). Eighteen ewes with 39.7±4 kg mean body weight, kept in individual pens, were randomly assigned to one of the following treatments: T1: TWH, T2: TWH plus 200 g DW, T3: TWH plus 300 g DW. The ewes were synchronized with 40 mg fluorogestone acetate (FGA) and 400 UI equine chorionic gonadotropin (eCG). Data were analyzed as a completely randomized design using the GLM procedure. DW supplementation had no effect on dry matter intake (p>0.05); however, a slight decrease of TWH intake was observed as DW supplementation increased. No differences (p>0.05) were found in the beginning of estrus, percentage of ewes presenting it, its duration, or pregnancy rate. There were no differences (p>0.05) on P4 concentration among treatments, or treatmentxperiod interaction (p>0.05). However the period was significant (p<0.01), since the P4 levels increased as time increased after the removal of the FGA device and eCG application. PMID:25049670

  16. Physiological and morphological effects of high water tables on early growth of giant reed (Arundo donax), elephant grass (Pennisetum purpureum), energycane and sugarcane (Saccharum spp.)

    SciTech Connect

    Jennewein, Stephen Peter

    2013-01-01

    Here, an increasing demand for renewable energy sources has spurred interest in high-biomass crops used for energy production. Species potentially well-suited for biofuel production in the seasonally wet organic Everglades Agricultural Area (EAA) of Florida include giant reed (Arundo donax), elephant grass (Pennisetum Purpureum), energycane (Saccharum spp.), and sugarcane (Saccharum spp.). The objectives in this study were to evaluate the role of fluctuating water tables on the morphology, physiology, and early season growth of these four genotypes. The candidate genotypes were grown in a greenhouse under three water table depths, defined by distance of the water table from the soil surface: two constant water tables (-16 cm and -40 cm) along with a flood cycle (2 weeks of flood to the soil level followed by 2 weeks at -40 cm from the soil level). The genotypes included CP 89-2143 (sugarcane), L 79-1002 (energycane), Merkeron (elephant grass), and wild type (giant reed). The experiment was repeated for plant cane, first ratoon, and successive plant cane crop cycles. Reductions in dry matter yield were observed among genotypes subjected to the -40 cm drained, periodically flooded (40F) water table relative to the -40 cm constant (40C) or -16 cm constant (16C). Plant cane dry weights were reduced by 37% in giant reed, 52% in elephant grass, 42% in energycane, and 34% in sugarcane in the 40F compared to 40C water table treatments. Similarly, in the first ratoon crop dry weights were reduced by 29% in giant reed, 42% in elephant grass, 27% in energycane, and 62% in sugarcane. In plant cane and successive plant cane, average total dry weight was greatest for elephant grass whereas ratoon total dry weight was greatest for energycane. Genotype had more pronounced effects on physiological attributes than water table including the highest stomatal conductance and SPAD values in giant reed, and the highest stalk populations in elephant grass and

  17. Impediments to hybridization between Napiergrass (Pennisetum purpureum Schum.) and other Pennisetum species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Napiergrass (Pennisetum purpureum Schum.) is a robust, perennial, warm-season grass that grows throughout the tropical and sub-tropical regions of the world. Some genotypes have sufficient winter hardiness to survive winters in the Gulf coast region of the United States. However, germplasm with in...

  18. Influence of different chemical pretreatments of elephant grass (Pennisetum purpureum, Schum.) used as a substrate for cellulase and xylanase production in submerged cultivation.

    PubMed

    Menegol, Daiane; Scholl, Angélica Luisi; Dillon, Aldo José Pinheiro; Camassola, Marli

    2016-09-01

    This study evaluated the potential use of elephant grass biomass, a highly productive species, for cellulase and xylanase production by the cellulolytic mutant Penicillium echinulatum 9A02S1 in submerged cultivation, using untreated biomass, biomass pretreated with different concentrations of NaOH, H2SO4 or NH4OH, or biomass pretreated with H2O at 121 °C. For filter paper activity, all cultivation carried out with pretreated elephant grass under the evaluated conditions showed superior activity when compared with the control (untreated elephant grass). The activities of endoglucanases and β-glucosidases were higher in the cultivation prepared from pretreated samples than the control made with cellulose (Celuflok(®)). Without pretreatment, elephant grass can be used for xylanase production, enabling similar activities to those obtained in the cultivation with cellulose, reducing the enzyme production cost. These results indicate that the pretreatment of elephant grass, especially when pretreated with H2SO4, may be used as a partial or total replacement for cellulose to cellulase production, and untreated elephant grass may be used for xylanase production.

  19. Cumulative effects of sewage sludge and effluent mixture application on soil properties of a sandy soil under a mixture of star and kikuyu grasses in Zimbabwe

    NASA Astrophysics Data System (ADS)

    Madyiwa, S.; Chimbari, M.; Nyamangara, J.; Bangira, C.

    Although sewage effluent and sludge provides nutrients for plant growth, its continual use over extended periods can result in the accumulation of heavy metals in soils and in grass to levels that are detrimental to the food chain. This study was carried in 2001 out at Firle farm, owned by the Municipality of Harare, to assess heavy metal loading on a sandy soil and uptake of the metals by pasture grass consisting of a mixture of Cynodon nlemfuensis (star grass) and Pennisetum clandestinum Chiov (kikuyu grass) following sewage effluent and sludge application for 29 years. Firle Farm receives treated effluent and sludge emanating from domestic and industrial sources. Soil and grass samples were taken from the study area, consisting of 3 ha of non-irrigated area (control) and 1.3 ha of irrigated area. Both the soil and grass samples were tested for Cu, Zn, Ni and Pb using atomic absorption spectrophotometry. Sewage sludge addition resulted in high levels of soil pollution, especially in the 20 cm horizon, in the irrigated area when compared to the control. Grasses took up moderate levels of Cu and Zn, and limited levels of Pb. Nickel was not detectable in grasses despite high levels in the irrigated soil. Copper uptake was several times higher than the suggested potentially toxic level of 12 mg/kg [Soil Science Society of America, Micronutrients in agriculture, second ed., Wisconsin, USA, 1991]. Lead uptake averaged 1.0 mg/kg, which was below 10 mg/kg the suggested limit for agronomic crops [E.M. Seaker, Zinc, copper, cadmium and lead in minespoil, water and plants from reclaimed mine land amended with sewage sludge, 1991]. Cu and Zn showed relatively higher mobility down the soil profile than Ni and Pb. Even then, the concentrations in the lower soil layers were very small, suggesting that the metals were unlikely to contaminate groundwater. There was no direct correlation between metal levels in soils and grasses. It was postulated that it is the bio

  20. DNA elimination in embryogenic development of Pennisetum glaucum x Pennisetum purpureum (Poaceae) hybrids.

    PubMed

    Nunes, J D; Azevedo, A L S; Pereira, A V; Paula, C M P; Campos, J M S; Lédo, F J S; Santos, V B

    2013-10-22

    Interspecific hybridization between Napier grass (Pennisetum purpureum), which is widely grown in Brazil for cattle forage, and pearl millet (Pennisetum glaucum) has been used as a breeding strategy for the development of improved cultivars. However, the hybrid between these two species is sterile due to its triploid condition (2n = 3x = 21 chromosomes), which hinders its use in crop breeding programs. It is known that genomic alterations result from the hybridization process. In order to measure the loss of DNA during embryo development, we used flow cytometry to estimate the nuclear DNA content of triploid and tetraploid embryos produced by interspecific hybridization between Napier grass and pearl millet. The triploid and tetraploid hybrids had a mean DNA content of 4.99-4.87 and 5.25-4.84 pg, at 10 and 30 days after pollination, respectively. The mean reduction in DNA content was higher in the tetraploid hybrids. The flow cytometry results revealed progressive genomic instability in these triploid and tetraploid hybrids, with this instability causing significant alterations in the DNA content of the hybrids.

  1. Apomictic and sexual pearl millet X Pennisetum squamulatum hybrids

    SciTech Connect

    Dujardin, M.; Hanna, W.W.

    1983-01-01

    Pennisetum squamulatum Fresen, an apomictic East African grass (2n = 54) was crossed to tetraploid (2n = 28) sexual pearl millet, P. americanum L. Leeke to study the potential for germplasm exchange. Twenty interspecific hybrids (2n = 41) with 14 pearl millet and 27 P. squamulatum chromosomes were obtained. All resembled P. squamulatum in perennial growth habit and inflorescence characteristics and resembled pearl millet in leafiness and pencillate anther tips. Seventeen of these hybrids were more vigorous than either parent. The most common chromosome association at metaphase I was 18 bivalents plus 5 univalents. At anaphase I and telophase I laggards, fragments, and unequal chromosome distribution were observed. Fifteen of 17 interspecific hybrids reproduced by facultative apomixis, one was sexual and one was an obligate apomict. Ovules with aposporous embryo sacs ranged from 1 to 93% in facultative apomictic plants. Morphological characteristics and chromosome numbers of open-pollinated progeny from the apomictic interspecific hybrid were identical to those of the seed parent indicating obligate apomictic reproduction. Both sexual and apomictic hybrids were partially male fertile with pollen stainability ranging from 29 percent to 79 percent and seed-set ranging from 1 to 60 seed per inflorescence under open-pollination. Development of fertile apomictic pearl millet-P. squamulatum interspecific hybrids appears to be a very useful tool for the transfer of genes for apomixis from the wild species to pearl millet.

  2. Description of a new species of Oligosita Walker (Chalcidoidea: Trichogrammatidae), egg parasitoid of Balclutha brevis Lindberg (Homoptera: Cicadellidae) living on Pennisetum setaceum, from Italy.

    PubMed

    Bella, Salvatore; Cupani, Sebastiano; D'urso, Vera; Laudonia, Stefania; Sinno, Martina; Viggiani, Gennaro

    2015-11-06

    A new species of Oligosita Walker (Chalcidoidea: Trichogrammatidae), O. balcluthae Viggiani et Laudonia n. sp., is described as a parasitoid of the eggs of Balclutha brevis Lindberg (Homoptera: Cicadellidae) associated with crimson fountain grass, Pennisetum setaceum (Poaceae) in Italy. Morphological features and biology of the new species are discussed and illustrated. The 28S-D2 and ITS2 regions were successfully amplified and sequenced.

  3. Effect of cadmium on growth, photosynthesis, mineral nutrition and metal accumulation of bana grass and vetiver grass.

    PubMed

    Zhang, Xingfeng; Gao, Bo; Xia, Hanping

    2014-08-01

    An experiment was conducted to evaluate the differential effects of Cd contamination on the growth, photosynthesis, mineral nutrition and Cd accumulation of bana grass (Pennisetum americanum × Pennisetum purpureum) and vetiver grass (Vetiveria zizanioides). Bana grass accumulated 48-453 and 25-208 mg kg(-1) in plant roots and shoots, respectively, at 15-100 mg kg(-1) soil Cd concentration, while vetiver grass accumulated 167-396 and 0.13-9.0 mg kg(-1). These results indicated that bana grass was a Cd accumulator while vetiver grass was a Cd excluder. The ratio of root to shoot biomass was significantly increased in vetiver grass, while it was unchanged in bana grass by Cd pollution. This suggests that excluders may allocate more energy to roots than shoots under Cd pollution compared to un-contaminated condition, while accumulators may allocate equal proportions of energy to roots and shoots. For bana grass, soil Cd pollution significantly decreased the concentration of Fe and Mn in roots as well as the translocation factors of Zn and K. For vetiver grass, soil Cd pollution significantly decreased the concentration of Fe in roots and had no influence on the translocation factors of Fe, Mn, Cu, Zn, Mg, K and Ca. Soil Cd pollution showed no significant effect on chlorophyll content and photosynthetic rates in either of the grasses. The water content and leaf transpiration rate were significantly increased by Cd pollution in bana grass, while they were unchanged in vetiver grass. The results indicated that the energy allocation and mineral nutrition characteristics may aid in screening suitable plant species for phytoremediation.

  4. Field productivities of Napier grass for production of sugars and ethanol.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Napier grass (Pennisetum purpureum (L) Schum) is being developed as a bioenergy crop for production in the southeastern United States. An important criterion for selecting a crop is establishing a consistent and dependable source of feedstock. In this study, we considered the effects of fertilizer a...

  5. Nutritive value and fermentation parameters of warm-season grass silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to investigate the nutritive value and fermentation characteristics of different species of warm-season grass silages treated with or without bacterial inoculants in the summer and fall. Nine forage species and cultivars, elephantgrass (Pennisetum purpureum Schumach),...

  6. Novel application of ALMANAC: Modelling a functional group, exotic warm-season perennial grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduced perennial C4 grasses such buffelgrass (Pennisetum ciliare [(L.) Link]) and old world bluestems (OWB), including genera such as Bothriochloa Kuntze, Capillipedium Stapf, and Dichanthium Willemet have the potential to dominate landscapes. A process-based model that realistically simulates ...

  7. Co-occurence of Invasive Species on Priority TES Installations

    DTIC Science & Technology

    2006-05-01

    forb O,F San Bernadino Ft. Irwin CA Desert Tortoise African Rue Peganum harmala forb O San Bernadino Ft. Irwin CA Desert Tortoise Curlyleaf Pondweed...forb O AZ Desert Tortoise African Rue Peganum harmala forb O AZ Desert Tortoise Kikuyugrass Pennisetum clandestinum grass AZ Desert...Name Form Habitat County Border County TX BCV & GCW Guineagrass Panicum maximum grass O,W TX BCV & GCW African Rue Peganum harmala forb O TX

  8. Ploidy determination of buffel grass accessions in the USDA National Plant Germplasm System collection by flow cytometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Buffelgrass [Pennisetum ciliare (L.) Link syn. Cenchrus ciliaris L.] is an important forage and range grass in many of the semi-arid tropical and subtropical regions of the world. The species reproduces primarily by apomixis but it is highly diverse because a wide array of different apomictic ecoty...

  9. Searching for microbial biological control candidates for invasive grasses: coupling expanded field research with strides in biotechnology and grassland restoration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly invasive grasses (e.g. Bromus spp., Pennisetum ciliare, Taeniatherum caput-medusae) are largely unabated in much of the arid Western U.S., despite more than 70 years of control attempts with a wide array of tools and management practices. The development and sustained integration of new appro...

  10. Evolution of the apomixis transmitting chromosome in Pennisetum

    PubMed Central

    2011-01-01

    Background Apomixis is an intriguing trait in plants that results in maternal clones through seed reproduction. Apomixis is an elusive, but potentially revolutionary, trait for plant breeding and hybrid seed production. Recent studies arguing that apomicts are not evolutionary dead ends have generated further interest in the evolution of asexual flowering plants. Results In the present study, we investigate karyotypic variation in a single chromosome responsible for transmitting apomixis, the Apospory-Specific Genomic Region carrier chromosome, in relation to species phylogeny in the genera Pennisetum and Cenchrus. A 1 kb region from the 3' end of the ndhF gene and a 900 bp region from trnL-F were sequenced from 12 apomictic and eight sexual species in the genus Pennisetum and allied genus Cenchrus. An 800 bp region from the Apospory-Specific Genomic Region also was sequenced from the 12 apomicts. Molecular cytological analysis was conducted in sixteen Pennisetum and two Cenchrus species. Our results indicate that the Apospory-Specific Genomic Region is shared by all apomictic species while it is absent from all sexual species or cytotypes. Contrary to our previous observations in Pennisetum squamulatum and Cenchrus ciliaris, retrotransposon sequences of the Opie-2-like family were not closely associated with the Apospory-Specific Genomic Region in all apomictic species, suggesting that they may have been accumulated after the Apospory-Specific Genomic Region originated. Conclusions Given that phylogenetic analysis merged Cenchrus and newly investigated Pennisetum species into a single clade containing a terminal cluster of Cenchrus apomicts, the presumed monophyletic origin of Cenchrus is supported. The Apospory-Specific Genomic Region likely preceded speciation in Cenchrus and its lateral transfer through hybridization and subsequent chromosome repatterning may have contributed to further speciation in the two genera. PMID:21975191

  11. In Silico and Fluorescence In Situ Hybridization Mapping Reveals Collinearity between the Pennisetum squamulatum Apomixis Carrier-Chromosome and Chromosome 2 of Sorghum and Foxtail Millet

    PubMed Central

    Sapkota, Sirjan; Conner, Joann A.; Hanna, Wayne W.; Simon, Bindu; Fengler, Kevin; Deschamps, Stéphane; Cigan, Mark; Ozias-Akins, Peggy

    2016-01-01

    Apomixis, or clonal propagation through seed, is a trait identified within multiple species of the grass family (Poaceae). The genetic locus controlling apomixis in Pennisetum squamulatum (syn Cenchrus squamulatus) and Cenchrus ciliaris (syn Pennisetum ciliare, buffelgrass) is the apospory-specific genomic region (ASGR). Previously, the ASGR was shown to be highly conserved but inverted in marker order between P. squamulatum and C. ciliaris based on fluorescence in situ hybridization (FISH) and varied in both karyotype and position of the ASGR on the ASGR-carrier chromosome among other apomictic Cenchrus/Pennisetum species. Using in silico transcript mapping and verification of physical positions of some of the transcripts via FISH, we discovered that the ASGR-carrier chromosome from P. squamulatum is collinear with chromosome 2 of foxtail millet and sorghum outside of the ASGR. The in silico ordering of the ASGR-carrier chromosome markers, previously unmapped in P. squamulatum, allowed for the identification of a backcross line with structural changes to the P. squamulatum ASGR-carrier chromosome derived from gamma irradiated pollen. PMID:27031857

  12. In Silico and Fluorescence In Situ Hybridization Mapping Reveals Collinearity between the Pennisetum squamulatum Apomixis Carrier-Chromosome and Chromosome 2 of Sorghum and Foxtail Millet.

    PubMed

    Sapkota, Sirjan; Conner, Joann A; Hanna, Wayne W; Simon, Bindu; Fengler, Kevin; Deschamps, Stéphane; Cigan, Mark; Ozias-Akins, Peggy

    2016-01-01

    Apomixis, or clonal propagation through seed, is a trait identified within multiple species of the grass family (Poaceae). The genetic locus controlling apomixis in Pennisetum squamulatum (syn Cenchrus squamulatus) and Cenchrus ciliaris (syn Pennisetum ciliare, buffelgrass) is the apospory-specific genomic region (ASGR). Previously, the ASGR was shown to be highly conserved but inverted in marker order between P. squamulatum and C. ciliaris based on fluorescence in situ hybridization (FISH) and varied in both karyotype and position of the ASGR on the ASGR-carrier chromosome among other apomictic Cenchrus/Pennisetum species. Using in silico transcript mapping and verification of physical positions of some of the transcripts via FISH, we discovered that the ASGR-carrier chromosome from P. squamulatum is collinear with chromosome 2 of foxtail millet and sorghum outside of the ASGR. The in silico ordering of the ASGR-carrier chromosome markers, previously unmapped in P. squamulatum, allowed for the identification of a backcross line with structural changes to the P. squamulatum ASGR-carrier chromosome derived from gamma irradiated pollen.

  13. Energy utilization, nitrogen balance and microbial protein supply in cattle fed Pennisetum purpureum and condensed tannins.

    PubMed

    Piñeiro-Vázquez, A T; Canul-Solis, J R; Alayón-Gamboa, J A; Chay-Canul, A J; Ayala-Burgos, A J; Solorio-Sánchez, F J; Aguilar-Pérez, C F; Ku-Vera, J C

    2017-02-01

    The aim of the experiment was to assess the effect of condensed tannins (CT) on feed intake, dry matter digestibility, nitrogen balance, supply of microbial protein to the small intestine and energy utilization in cattle fed a basal ration of Pennisetum purpureum grass. Five heifers (Bos taurus × Bos indicus) with an average live weight of 295 ± 19 kg were allotted to five treatments consisting of increasing levels of CT (0, 1, 2, 3 and 4% CT/kg DM) in a 5 × 5 Latin square design. Dry matter intake (DMI) was similar (p > 0.05) between treatments containing 0, 1, 2 and 3% of CT/kg DM and it was reduced (p < 0.05) to 4% CT (5.71 kg DM/day) with respect to that observed with 0% CT (6.65 kg DM/day). Nitrogen balance, purine derivatives excretion in urine, microbial protein synthesis and efficiency of synthesis of microbial nitrogen in the rumen were not affected (p ≥ 0.05) by the increase in the levels of condensed tannins in the ration. Energy loss as CH4 was on average 2.7% of the gross energy consumed daily. Metabolizable energy intake was 49.06 MJ/day in cattle fed low-quality tropical grass with a DMI of 6.27 kg/day. It is concluded that concentrations of CT between 2 and 3% of DM of ration reduced energy loss as CH4 by 31.3% and 47.6%, respectively, without affecting intakes of dry and organic matter; however, digestibilities of dry and organic matter are negatively affected.

  14. Grass allergy

    MedlinePlus

    ... itself may not be harmful, fertilizers, insecticides , and herbicides applied to the grass can be poisonous. ... of any sort such as fertilizer, insecticide, or herbicide, find out the product name and ingredients.

  15. Ecophysiological responses of native and invasive grasses to simulated warming and drought

    NASA Astrophysics Data System (ADS)

    Ravi, S.; Law, D. J.; Wiede, A.; Barron-Gafford, G. A.; Breshears, D. D.; Dontsova, K.; Huxman, T. E.

    2011-12-01

    Climate models predict that many arid regions around the world - including the North American deserts - may become affected more frequently by recurrent droughts. At the same time, these regions are experiencing rapid vegetation transformations such as invasion by exotic grasses. Thus, understanding the ecophysiological processes accompanying exotic grass invasion in the context of rising temperatures and recurrent droughts is fundamental to global change research. Under ambient and warmer (+ 4° C) conditions inside the Biosphere 2 facility, we compared the ecophysiological responses (e.g. photosynthesis, stomatal conductance, pre-dawn leaf water potential, light & CO2 response functions, biomass) of a native grass - Heteropogan contortus (Tangle head) and an invasive grass - Pennisetum ciliare (Buffel grass) growing in single and mixed communities. Further, we monitored the physiological responses and mortality of these plant communities under moisture stress conditions, simulating a global change-type-drought. The results indicate that the predicted warming scenarios may enhance the invasibility of desert landscapes by exotic grasses. In this study, buffel grass assimilated more CO2 per unit leaf area and out-competed native grasses more efficiently in a warmer environment. However, scenarios involving a combination of drought and warming proved disastrous to both the native and invasive grasses, with drought-induced grass mortality occurring at much shorter time scales under warmer conditions.

  16. Contrasting strategies to cope with drought conditions by two tropical forage C4 grasses

    PubMed Central

    Cardoso, Juan Andrés; Pineda, Marcela; Jiménez, Juan de la Cruz; Vergara, Manuel Fernando; Rao, Idupulapati M.

    2015-01-01

    Drought severely limits forage productivity of C4 grasses across the tropics. The avoidance of water deficit by increasing the capacity for water uptake or by controlling water loss are common responses in forage C4 grasses. Napier grass (Pennisetum purpureum) and Brachiaria hybrid cv. Mulato II are tropical C4 grasses used for livestock production due to their reputed resistance to drought conditions. However, there is scant information on the mechanisms used by these grasses to overcome water-limited conditions. Therefore, assessments of cumulative transpired water, shoot growth, leaf rolling, leaf gas exchange, dry mass production and a number of morpho-physiological traits were recorded over a period of 21 days under well-watered or drought conditions. Drought reduced shoot dry mass of both grasses by 35 %, yet each grass exhibited contrasting strategies to cope with water shortage. Napier grass transpired most available water by the end of the drought treatment, whereas a significant amount of water was still available for Mulato II. Napier grass maintained carbon assimilation until the soil was fairly dry, whereas Mulato II restricted water loss by early stomatal closure at relatively wet soil conditions. Our results suggest that Napier grass exhibits a ‘water-spending’ behaviour that might be targeted to areas with intermittent drought stress, whereas Mulato II displays a ‘water-saving’ nature that could be directed to areas with longer dry periods. PMID:26333827

  17. Grass and herbaceous plants for biomass

    SciTech Connect

    Prine, G.M.; Mislevy, P.

    1983-01-01

    Florida has little fossil fuel resources, but the state does have an adequate climate for high plant biomass production. Grasses and herbaceous plants are renewable resources which could furnish a portion of Florida's energy needs. Dry matter yields of various annual and perennial grasses and herbaceous plants which can be grown in Florida are presented in this paper. Residues of crops already being grown for other reasons would be an economical source of biomass. The best alternative for an energy crop appears to be tropical perennial shrub-like legumes and tall, strong-stemmed grasses that have their top growth killed by frosts each winter and that regrow annually from below-ground regenerative plant parts. Napiergrass or elephantgrass (Pennisetum purpureum L.), leucaena (Leucaena leucocephala (Lam.) de Wit) and sugarcane (Saccharum spp.) are examples of such energy plants. Napiergrass (PI 300086) had dry matter yields when cut once at the end of the season of 44.5 and 52.4 Mg/ha in 1981 and 1982 respectively, at Gainesville, Fla. and 56.7 Mg/ha for the first season after planting (1982) at Ona, Fla. A dry matter yield of 73 Mg/ha was obtained from a 10-year-old clump of leucaena at Gainesville in 1981. However, research needs to be conducted on methods of harvesting and storing biomass plants to be used for energy. Napiergrass and other grasses may be solar dried standing after a freeze or following cutting in the fall and then be rolled into large bales for storage in the open or crude shelters. A year-round supply of economical biomass must be available before grasses and herbaceous plants are widely grown and used for energy purposes. 6 references.

  18. Underutilized Grasses.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial warm-season grasses have been recognized for having several properties, such as high rates of net photosynthesis, energy and labor savings, and reduced soil and nutrient losses that make them better suited for biofuel production than many annual crops. Prairie cordgrass (Spartina pectinat...

  19. Liquid hot water pretreatment of energy grasses and its influence of physico-chemical changes on enzymatic digestibility.

    PubMed

    Yu, Qiang; Liu, Jing; Zhuang, Xinshu; Yuan, Zhenhong; Wang, Wen; Qi, Wei; Wang, Qiong; Tan, Xuesong; Kong, Xiaoying

    2016-01-01

    Pennisetum hybrid I, II and switchgrass were pretreated with liquid hot water to enhance the release of sugars. The optimum hydrolysis factor for three energy grasses was 5.98, and the total xylose yield was 88.4%, 98.1% and 83.6% for grass I, II and S. It was indicated that the ratio of syringyl and guaiacyl units of lignin played an important role on the hemicellulose hydrolysis in LHW than branch degree, but latter contributed more on the characterization of xylooligomers degree of polymerization. Moreover, the analysis of multi-scale changes of substrate suggested that cellulose crystallinity index and degree of polymerization seemed no direct relationships for increase of enzymatic digestibility. While lignin barrier was the main factor limiting efficiency of sugar release, and Pennisetum hybrid with low lignin content and high sugar recovery was proved to be a prospective plant feedstock for cellulosic ethanol production.

  20. The role of wild grasses in the management of lepidopterous stem-borers on maize in the humid tropics of western Africa.

    PubMed

    Ndemah, R; Gounou, S; Schulthess, F

    2002-12-01

    Sites in the humid forest of Cameroon and the derived savanna of Benin were selected to evaluate the effect of planting border rows of wild host plants on lepidopterous stem-borer infestations and on maize yield. Grass species were chosen that in surveys and greenhouse trials were highly attractive to ovipositing female moths but with offspring mortality of close to 100%, thus acting as trap plants. In Cameroon, elephant grass Pennisetum purpureum Moench significantly lowered infestations of Busseola fusca (Fuller), Sesamia calamistis Hampson and Eldana saccharina Walker and increased yields of maize though the differences were not significant during all three cropping seasons. In 1998 in Benin, the only grass tested, Pennisetum polystachion L., significantly increased parasitism of mainly S. calamistis eggs by Telenomus spp. and larvae by Cotesia sesamiae Cameron and reduced numbers of the cob-borer Mussidia nigrivenella Ragonot. In 1999, three grass species; P. polystachion, Sorghum arundinaceum (Desv.) Stapf and Panicum maximum Jacq. were tested. Panicum maximum was the most efficient species for suppressing S. calamistis and M. nigrivenella infestations and enhancing egg and larval parasitism. In the Benin trials, with the exception of M. nigrivenella damage to cobs, the grass species tested had no beneficial effect on yield because pest densities were too low and also rodent damage to maize was enhanced with grasses in the vicinity of the crop. By contrast, stand losses due to Fusarium verticillioides Sacc. (Nirenberg), were significantly reduced by border rows of grasses.

  1. Constancy of local spread rates for buffelgrass (Pennisetum ciliare L.) in the Arizona Upland of the Sonoran Desert

    USGS Publications Warehouse

    Olsson, Aaryn D.; Betancourt, Julio L.; Crimmins, Michael A.; Marsh, Stuart E.

    2012-01-01

    In North American deserts, grass invasions threaten native vegetation via competition and altered fire regimes. Accurate prediction and successful mitigation of these invasions hinge on estimation of spread rates and their degree of constancy in time and space. We used high-resolution aerial photographs from 11 sites in the Santa Catalina Mountains, southern Arizona to reconstruct the spread of buffelgrass (Pennisetum ciliare), a C4 perennial bunchgrass, since 1980. The total area infested was fit to a logistic model and residuals of the model were compared to climatic factors of the corresponding and lagged time periods. Infestations grew from small colonizing patches in the 1980s to 66 ha in 2008, doubling every 2.26–7.04 years since 1988. Although buffelgrass germination, establishment and distribution are favored by wet summers and warm winters, climate variables did not predict spread rates. Buffelgrass has grown at a constant rate, at least since 1988, when much of its expansion took place. In the study area, minimum requirements are met almost every year for germination and reproduction, establishing a consistent baseline for spread that manifests as a constant spread rate.

  2. Assessment of genetic diversity in napiergrass (Pennisetum purpureum Schum.) using microsatellite, single-nucleotide polymorphism, and insertion-deletion markers from pearl millet (Pennisetum glaucum [L] R. Br.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Napiergrass (Pennisetum purpureum Schumacher) is a well established perennial fodder crop of African origin and is a potential bio-energy crop. The absence of genome sequence information in napiergrass has become an obstacle in the development of sequence specific markers which often involves a high...

  3. Belowground carbon cycle of Napier and Guinea grasses

    NASA Astrophysics Data System (ADS)

    Sumiyoshi, Y.; Crow, S. E.; Litton, C. M.; Deenik, J. L.

    2011-12-01

    Soil carbon (C) sequestration may partially offset rising atmospheric CO2 concentration. Napier grass (Pennisetum purpureum) and Guinea grass (Panicum maximum), in particular, are perennial C4 grasses with high capacity to produce large amounts of both aboveground and belowground biomass. Thus, they have a potential to sequester soil C while simultaneously provide aboveground biomass for energy production. In this study, both grasses were ratooned (no-till) to leave belowground biomass intact and facilitate C accumulation through improvement of soil aggregation. The primary objective of the study was to determine if and how these grasses sequester soil C. For 8 selected grass varieties, we: (1) determined the quantity and quality of belowground C input, (2) quantified changes in soil organic C (SOC) during two harvesting cycles (May 2010 to July 2011), and (3) fractionated soil C pools to determine where changes in SOC occurred. Soil-surface CO2 efflux and root biomass were used as measures of the quantity of belowground C input. Root lignin/N ratios and decay constants from litterbag studies were used as measures of the belowground C input quality. We hypothesized that grass varieties with higher quantity and lower quality of belowground C input would sequester more soil C. Root biomass collected on May 2010 ranged from 13 to 302 g m-2 at 15 cm depth, where Local (Napier) and OG05 (Guinea) varieties were significantly greater than the K06 variety (Guinea). However, cumulative soil-surface CO2 efflux showed no significant differences between the three varieties. Root Lignin/N ranged from 16 to 55 and Guinea varieties were significantly higher on average than Napier varieties. Root decay constants were variable among varieties, with OG05 and K06 showing higher resistance to decay compared to Local. Soil C sequestration potentials and factors affecting the process are imperative to determine suitable variety for bioenergy production.

  4. Induction of segmental interchanges in pearl millet (Pennisetum typhides).

    PubMed

    Lal, J; Srinivasachar, D

    1979-01-01

    Dry seeds of two varieties of Pennisetum typhoides (2n=14), 'Tift 23-B' and 'Bil-3B', were treated with gamma rays, diethyl sulphate (DES) and ethylene imine (EI) at their approximate LD50 dosages and the pollen mother cells of the M1 (first generation immediately after the seed treatment) plants were analysed at diakinesis for multivalent configurations resulting from segmental interchanges. While quadrivalents and trivalents were commonly found in all the mutagenic treatments, hexavalents were seen in the gamma-ray treatment only. Ring quadrivalents were common in all the treatments and their frequency was higher in gamma-ray treatment than in the treatments with the chemical mutagens of which EI produced more quadrivalents than DES. The variety 'BIL3B' was more responsive to all the mutagens used than 'Tift-23B' in which, excepting in gamma-ray treatment, no multivalents were observed in EI and DES treatments.The quadrivalents induced by different mutagens were of different types involving different chromosomes, indicating some kind of specificity of the mutagens in causing chromosome breaks. Thus, in EI-induced quadrivalents the nucleolar chromosome, the shortest chromosome of the complement, was involved, whereas in the case of DES and gamma rays it was the longest chromosome of the complement that was involved in the quadrivalent. Apparently the breaks must have been produced in different chromosomes preferentially.Self-pollinated seeds of two heterozygotes whose interchanges were induced by EI and gamma rays were given a second cycle treatment with gamma rays, again at the LD50 dosage (35 kR), and interchange stocks involving different chromosomes, up to a maximum of eight chromosomes were realized. Alternate use of EI and gamma rays offered better possibilities of obtaining inter-change heterozygotes involving more, if not all, chromosomes in a ring than two successive treatments with gamma rays alone.

  5. Development of innovative technique that may be used as models for the increase of biomass production with grasses and other species

    NASA Astrophysics Data System (ADS)

    Burton, G. W.; Hanna, W. W.

    1981-09-01

    Techniques for biomass increase are discussed: irradiation breeding of sterile triploid turf bermuda grasses; irradiation breeding of sterile Coastcross-1, a forage grass hybrid to increase winter hardiness; heterosis resulting from crossing specific irradiation induced mutants with their normal inbred parent; use of mitomycin and streptomycin to create cytoplasmic male sterile mutants in pearl millet; biomass of napiergrass; evaluation of mutagen induced lignin mutants to maximize metabolizable energy in sorghum; interspecific crosses in Pennisetum; production of homozygous translocation tester stocks; use of radiation to induce and transfer reproductive behavior in plants; and genetics of radiation induced mutations.

  6. Reversing land degradation through grasses: a systematic meta-analysis in the Indian tropics

    NASA Astrophysics Data System (ADS)

    Mandal, Debashis; Srivastava, Pankaj; Giri, Nishita; Kaushal, Rajesh; Cerda, Artemi; Meherul Alam, Nurnabi

    2017-02-01

    Although intensive agriculture is necessary to sustain the world's growing population, accelerated soil erosion contributes to a decrease in the environmental health of ecosystems at local, regional and global scales. Reversing the process of land degradation using vegetative measures is of utmost importance in such ecosystems. The present study critically analyzes the effect of grasses in reversing the process of land degradation using a systematic review. The collected information was segregated under three different land use and land management situations. Meta-analysis was applied to test the hypothesis that the use of grasses reduces runoff and soil erosion. The effect of grasses was deduced for grass strip and in combination with physical structures. Similarly, the effects of grasses were analyzed in degraded pasture lands. The overall result of the meta-analysis showed that infiltration capacity increased approximately 2-fold after planting grasses across the slopes in agricultural fields. Grazing land management through a cut-and-carry system increased conservation efficiencies by 42 and 63 % with respect to reduction in runoff and erosion, respectively. Considering the comprehensive performance index (CPI), it has been observed that hybrid Napier (Pennisetum purpureum) and sambuta (Saccharum munja) grass seem to posses the most desirable attributes as an effective grass barrier for the western Himalayas and Eastern Ghats, while natural grass (Dichanthium annulatum) and broom grass (Thysanolaena maxima) are found to be most promising grass species for the Konkan region of the Western Ghats and the northeastern Himalayan region, respectively. In addition to these benefits, it was also observed that soil carbon loss can be reduced by 83 % with the use of grasses. Overall, efficacy for erosion control of various grasses was more than 60 %; hence, their selection should be based on the production potential of these grasses under given edaphic and agro

  7. Sonoran Desert ecosystem transformation by a C4 grass without the grass/fire cycle

    USGS Publications Warehouse

    Olsson, Aaryn D.; Betancourt, Julio; McClaran, Mitchel P.; Marsh, Stuart E.

    2012-01-01

    Aim Biological invasions facilitate ecosystem transformation by altering the structure and function, diversity, dominance and disturbance regimes. A classic case is the grass–fire cycle in which grass invasion increases the frequency, scale and/or intensity of wildfires and promotes the continued invasion of invasive grasses. Despite wide acceptance of the grass–fire cycle, questions linger about the relative roles that interspecific plant competition and fire play in ecosystem transformations. Location Sonoran Desert Arizona Upland of the Santa Catalina Mountains, Arizona, USA. Methods We measured species cover, density and saguaro (Carnegiea gigantea) size structure along gradients of Pennisetum ciliare invasion at 10 unburned/ungrazed P. ciliare patches. Regression models quantified differences in diversity, cover and density with respect to P. ciliare cover, and residence time and a Fisher's exact test detected demographic changes in saguaro populations. Because P. ciliare may have initially invaded locations that were both more invasible and less diverse, we ran analyses with and without the plots in which initial infestations were located. Results Richness and diversity decreased with P. ciliare cover as did cover and density of most dominant species. Richness and diversity declined with increasing time since invasion, suggesting an ongoing transformation. The proportion of old-to-young Carnegiea gigantea was significantly lower in plots with dominant P. ciliare cover. Main conclusions Rich desert scrub (15–25 species per plot) was transformed into depauperate grassland (2–5 species per plot) within 20 years following P. ciliare invasion without changes to the fire regime. While the onset of a grass–fire cycle may drive ecosystem change in the later stages and larger scales of grass invasions of arid lands, competition by P. ciliare can drive small-scale transformations earlier in the invasion. Linking competition-induced transformation rates with

  8. Ecophysiological Responses of Invasive and Native Grass Communities with Simulated Warming

    NASA Astrophysics Data System (ADS)

    Quade, B.; Ravi, S.; Huxman, T. E.

    2010-12-01

    William Quade1, Sujith Ravi2, Ashley Weide2, Greg Barron-Gafford2, Katerina Dontsova2 and Travis E Huxman2 1Carthage College, WI 2 B2 Earthscience & UA Biosphere 2, University of Arizona, Tucson. Abstract Climate change, anthropogenic disturbances and lack of proper management practices have rendered many arid regions susceptible to invasions by exotic grasses with consequent ecohydrological, biogeochemical and socio economic implications. Thus, understanding the ecophysiological processes driving these large-scale vegetation shifts in drylands, in the context of rising temperatures and recurrent droughts is fundamental to global change research. Using the Biosphere 2 facility to maintain distinct temperature treatments of ambient and predicted warmer conditions (+ 4o C) inside, we compared the physiological (e.g. photosynthesis, stomatal conductance, biomass) responses of a native grass - Heteropogan contortus (Tanglehead) and an invasive grass - Pennisetum ciliare (Buffelgrass) growing in single and mixed communities. The results indicate that Buffelgrass can assimilate more CO2 per unit leaf area under current conditions, though warming seems to inhibit the performance when looking at biomass, photosynthesis and stomatal conductance. Under similar moisture regimes Buffelgrass performed better than Tangle head in mixed communities regardless of the temperature. Both grasses had decrease in stomatal conductance with warmer conditions, however the Buffel grass did not have the same decrease of conductance when planted in a mixed communities. Key words: Buffelgrass, Tanglehead, Biosphere 2, stomatal conductance, climate change

  9. Preferential recruitment of the maternal centromere-specific histone H3 (CENH3) in oat (Avena sativa L.) × pearl millet (Pennisetum glaucum L.) hybrid embryos.

    PubMed

    Ishii, Takayoshi; Sunamura, Naohiro; Matsumoto, Ayaka; Eltayeb, Amin Elsadig; Tsujimoto, Hisashi

    2015-12-01

    Chromosome elimination occurs frequently in interspecific hybrids between distantly related species in Poaceae. However, chromosomes from both parents behave stably in a hybrid of female oat (Avena sativa L.) pollinated by pearl millet (Pennisetum glaucum L.). To analyze the chromosome behavior in this hybrid, we cloned the centromere-specific histone H3 (CENH3) genes of oat and pearl millet and produced a pearl millet-specific anti-CENH3 antibody. Application of this antibody together with a grass species common anti-CENH3 antibody revealed the dynamic CENH3 composition of the hybrid cells before and after fertilization. Despite co-expression of CENH3 genes encoded by oat and pearl millet, only an oat-type CENH3 was incorporated into the centromeres of both species in the hybrid embryo. Oat CENH3 enables a functional centromere in pearl millet chromosomes in an oat genetic background. Comparison of CENH3 genes among Poaceae species that show chromosome elimination in interspecific hybrids revealed that the loop 1 regions of oat and pearl millet CENH3 exhibit exceptionally high similarity.

  10. Determination of in vitro free radical scavenging and antiproliferative effect of Pennisetum alopecuroides on cultured A549 human lung cancer cells

    PubMed Central

    Mathew, Githa Elizabeth; Mathew, Bijo; Gokul, S.; Krishna, Rahul; Farisa, M. P.

    2015-01-01

    Context: Pennisetum alopecuroides (Poaceae) is a grass predominantly distributed in tropics and sub tropics. It is used as a cattle feed in many regions. Aim: The objective of the present study was to investigate the in vitro free radical scavenging and antiproliferative activity of ethanol extract of P. alopecuroides (EEPA) on cultured A549 human lung cancer cell lines. Settings and Design: The anti-oxidant activity of ethanol extract was evaluated at dose level 12.5, 25, 50, 100, and 200 μg/ml. The in vitro antiproliferative activity was measured at doses of 10, 50, and 100 μg/ml. Materials and Methods: The free radical scavenging activity of the EEPA was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) method and in vitro antiproliferative activity on A549 human lung cancer cells was conducted by using MTT assay method. Results: The phytochemical screening revealed that the P. alopecuroides contained alkaloids, tannins, saponins, and flavonoids as the major secondary metabolites. The IC50 value of DPPH scavenging activity was found to be 44.41 μg/ml and 31.02 μg/ml  for a mixture of EEPA and standard ascorbic acid, respectively. In vitro MTT assay showed that EEPA had anti-proliferation effects on A549 cells in a dose dependent manner. Conclusions: This is the 1st time a pharmacological exploration of P. alopecuroides grasses has been conducted. We have shown that P. alopecuroides exhibits good free radical scavenging and strong in vitro cytotoxic activities against human lung cancer cell lines. PMID:26120234

  11. Herbage intake, methane emissions and animal performance of steers grazing dwarf elephant grass v. dwarf elephant grass and peanut pastures.

    PubMed

    Andrade, E A; Almeida, E X; Raupp, G T; Miguel, M F; de Liz, D M; Carvalho, P C F; Bayer, C; Ribeiro-Filho, H M N

    2016-10-01

    Management strategies for increasing ruminant legume consumption and mitigating methane emissions from tropical livestock production systems require further study. The aim of this work was to evaluate the herbage intake, animal performance and enteric methane emissions of cattle grazing dwarf elephant grass (DEG) (Pennisetum purpureum cv. BRS Kurumi) alone or DEG with peanut (Arachis pintoi cv. Amarillo). The experimental treatments were the following: DEG pastures receiving nitrogen fertilization (150 kg N/ha as ammonium nitrate) and DEG intercropped with peanut plus an adjacent area of peanut that was accessible to grazing animals for 5 h/day (from 0700 to 1200 h). The animals grazing legume pastures showed greater average daily gain and herbage intake, and shorter morning and total grazing times. Daily methane emissions were greater from the animals grazing legume pastures, whereas methane emissions per unit of herbage intake did not differ between treatments. Allowing animals access to an exclusive area of legumes in a tropical grass-pasture-based system can improve animal performance without increasing methane production per kg of dry matter intake.

  12. Pests in ornamental grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ornamental perennial grasses are becoming increasingly popular in the landscape due to their beauty and ease of care. Although few pest problems are encountered in ornamental grasses, they are not immune to insects and disease. Two lined spittlebugs (Prosapia bicincta) can cause damage to ornament...

  13. Grass flower development.

    PubMed

    Hirano, Hiro-Yuki; Tanaka, Wakana; Toriba, Taiyo

    2014-01-01

    Grasses bear unique flowers lacking obvious petals and sepals in special inflorescence units, the florets and the spikelet. Despite this, grass floral organs such as stamens and lodicules (petal homologs) are specified by ABC homeotic genes encoding MADS domain transcription factors, suggesting that the ABC model of eudicot flower development is largely applicable to grass flowers. However, some modifications need to be made for the model to fit grasses well: for example, a YABBY gene plays an important role in carpel specification. In addition, a number of genes are involved in the development of the lateral organs that constitute the spikelet. In this review, we discuss recent progress in elucidating the genes required for flower and spikelet development in grasses, together with those involved in fate determination of the spikelet and flower meristems.

  14. Ecological rehabilitation and phytoremediation with four grasses in oil shale mined land.

    PubMed

    Xia, H P

    2004-01-01

    Vetiver grass (Vetiveria zizanioides), bahia grass (Paspalum notatum), St. Augustine grass (Stenotaphrum secundatum), and bana grass (Pennisetum glaucumxP. purpureum) were selected to rehabilitate the degraded ecosystem of an oil shale mined land of Maoming Petro-Chemical Company located in Southwest of Guangdong Province, China. Among them, vetiver had the highest survival rate, up to 99%, followed by bahia and St. Augustine, 96% and 91%, respectively, whereas bana had the lowest survival rate of 62%. The coverage and biomass of vetiver were also the highest after 6-month planting. Fertilizer application significantly increased biomass and tiller number of the four grasses, of which St. Augustine was promoted most, up to 70% for biomass, while vetiver was promoted least, only 27% for biomass. Two heavy metals, lead (Pb) and cadmium (Cd) tested in this trial had different concentrations in the oil shale residue, and also had different contents and distributions in the four grass species. Concentrations of Pb and Cd in the four grasses presented a disparity of only 1.6-3.8 times, but their uptake amounts to the two metals were apart up to 27.5-35.5 times, which was chiefly due to the significantly different biomasses among them. Fertilizer application could abate the ability of the four species to accumulate heavy metals, namely concentration of heavy metals in plants decreased as fertilizer was applied. The total amount of metals accumulated by each plant under the condition of fertilization did not decrease due to an increase of biomass. In summary, vetiver may be the best species used for vegetation rehabilitation in oil shale disposal piles.

  15. Steers performance in dwarf elephant grass pastures alone or mixed with Arachis pintoi.

    PubMed

    Crestani, Steben; Ribeiro Filho, Henrique Mendonça Nunes; Miguel, Marcolino Frederico; de Almeida, Edison Xavier; Santos, Flávio Augusto Portela

    2013-08-01

    The inclusion of legumes in pasture reduces the need for mineral nitrogen applications and the pollution of groundwater; however, the agronomic and animal husbandry advantages with tropical legumes are still little known. The objective of this study was to quantify the effect of the use of forage peanut (Arachis pintoi cv. Amarillo) in dwarf elephant grass pastures (Pennisetum purpureum cv. BRS Kurumi) on forage intake and animal performance. The experimental treatments were dwarf elephant grass fertilized with 200 kg N/ha, and dwarf elephant grass mixed with forage peanut without mineral fertilizers. The animals used for the experiment were 12 Charolais steers (body weight (BW) = 288 ± 5.2 kg) divided into four lots (two per treatment). Pastures were managed under intermittent stocking with an herbage allowance of 5.4 kg dry matter of green leaves/100 kg BW. Dry matter intake (mean = 2.44% BW), the average daily gain (mean = 0.76 kg), and the stocking rate (mean = 3.8 AU/ha) were similar between the studied pastures, but decreased drastically in last grazing cycle with the same herbage allowance. The presence of peanut in dwarf elephant grass pastures was enough to sustain the stocking rate, but did not allow increasing forage intake and animal performance.

  16. Grass mulching effect on infiltration, surface runoff and soil loss of three agricultural soils in Nigeria.

    PubMed

    Adekalu, K O; Olorunfemi, I A; Osunbitan, J A

    2007-03-01

    Mulching the soil surface with a layer of plant residue is an effective method of conserving water and soil because it reduces surface runoff, increases infiltration of water into the soil and retard soil erosion. The effectiveness of using elephant grass (Pennisetum purpureum) as mulching material was evaluated in the laboratory using a rainfall simulator set at rainfall intensities typical of the tropics. Six soil samples, two from each of the three major soil series representing the main agricultural soils in South Western Nigeria were collected, placed on three different slopes, and mulched with different rates of the grass. The surface runoff, soil loss, and apparent cumulative infiltration were then measured under each condition. The results with elephant grass compared favorably with results from previous experiments using rice straw. Runoff and soil loss decreased with the amount of mulch used and increased with slope. Surface runoff, infiltration and soil loss had high correlations (R = 0.90, 0.89, and 0.86, respectively) with slope and mulch cover using surface response analysis. The mean surface runoff was correlated negatively with sand content, while mean soil loss was correlated positively with colloidal content (clay and organic matter) of the soil. Infiltration was increased and soil loss was reduced greatly with the highest cover. Mulching the soils with elephant grass residue may benefit late cropping (second cropping) by increasing stored soil water for use during dry weather and help to reduce erosion on sloping land.

  17. Characterizing compositional changes of Napier grass at different stages of growth for biofuel and biobased products potential.

    PubMed

    Takara, Devin; Khanal, Samir Kumar

    2015-01-01

    Napier grass, Pennisetum purpureum, is a high yielding, perennial feedstock that can be harvested year-round in (sub)tropical geographies of the world. Because of its high moisture content (∼ 80%w/w), Napier grass presents a unique opportunity for fractionation into solid and liquid streams, where the extruded cellulosic fibers can serve as a substrate for biofuel production, and the nutrient-rich juice can serve as a substrate for co-product generation. The aim of this study evaluated the effects of biomass age on constituents relevant to biofuel and biobased product generation. Although obvious morphological changes can be observed in the field due to natural senescence, the results obtained in this work suggested that the cellulose content does not change significantly with respect to age. Data surrounding the hemicellulose and lignin contents, however, were inconclusive as their degree of significance varied with the statistics applied to analyze the raw data.

  18. Leucaena and tall grasses as energy crops in humid lower south USA

    SciTech Connect

    Prine, G.M.; Woodard, K.R.; Cunilio, T.V.

    1994-12-31

    The tropical leguminous shrub/tree, leucaena (Leucaena spp. mainly leucocephala), and perennial tropical tall grasses such as elephantgrass (Pennisetum purpureum), sugarcane, and energycane (Saccharum spp.) are well adapted to the long growing seasons and high rainfall of the humid lower South. In much of the area the topgrowth is killed by frost during winter and plants regenerate from underground parts in spring. Selected accessions from a duplicated 373 accession leucaena nursery had an average annual woody stem dry matter production of 31.4 Mg ha{sup -1}. Average oven dry stem wood yields from selected accessions adjusted for environmental enrichment over the 4 growth seasons were 78.9 Mg ha{sup -1} total and average annual yield of 19.7 Mg ha{sup -1}. The tall perennial grasses have linear growth rates of 18 to 27 g m{sup 2}d{sup -1} for long periods (140 to 196 d and sometimes longer) each season. Oven dry biomass yields of tall grasses have varied from 20 to 45 Mg ha{sup -1} in mild temperature locations to over 60 Mg ha{sup -1} yr{sup -1} in warm subtropics of the lower Florida peninsula. Tall grasses and leucaena, once established, may persist for many seasons. A map showing the possible range of the crops in lower South is shown. Highest biomass yields of tall grasses have been produced when irrigated with sewage effluent or when grown on phosphatic clay and muck soils of south Florida. Several companies are considering using leucaena and/or tall grasses for bioenergy in the phosphatic mining area of Polk County, Florida.

  19. GRASS GIS Vector Processing: Towards GRASS 7

    NASA Astrophysics Data System (ADS)

    Metz, Markus; Landa, Martin; Petrasova, Anna; Petras, Vaclav; Chemin, Yann; Neteler, Markus

    2014-05-01

    The upcoming GRASS GIS 7 release improves not only raster processing and general design but the vector processing in the first place. GRASS GIS, as a topological GIS, recognizes that the topology plays the key role in the vector processing and analysis. Topology ensures that adjacent geographic components in a single vector map are related. In contrast to non-topological GIS, a border common to two areas exists only once and is shared between the two areas. Topological representation of vector data helps to produce and maintain vector maps with clean geometry as well as enables the user to perform certain analyses that can not be conducted with non-topological or spaghetti data. Non-topological vector data are automatically converted to a topological representation upon import. Further more, various cleaning tools exist to remove non-trivial topological errors. In the upcoming GRASS GIS 7 release the vector library was particularly improved to make it faster and more efficient with an improved internal vector file format. This new topological format reduces memory and disk space requirements, leading to a generally faster processing. Opening an existing vector requires less memory providing additionally support for large files. The new spatial index performs queries faster (compared to GRASS GIS 6 more than 10 times for large vectors). As a new option the user can select a file-based version of the spatial index for large vector data. All topological cleaning tools have been optimized with regard to processing speed, robustness, and system requirements. The topological engine comes with a new prototype for direct read/write support of Simple Features API/OGR. Additionally vector data can be directly exchanged with topological PostGIS 2 databases. Considering the wide spread usage of ESRI Shapefile, a non-topological format for vector data exchange, it is particularly advantageous that GRASS GIS 7 offers advanced cleaning tools. For power users and programmers, the

  20. Apomictic interspecific hybrids between pearl millet and Pennisetum orientale L. C. Rich

    SciTech Connect

    Hanna, W.W.; Dujardin, M.

    1982-07-01

    Pearl millet, Pennisetum americanum (L.) Leeke, is an important world food and forage crop. Pennisetum orientale L. C. Rich. has genes for apomixis, perennial growth habit, pest resistance, and drought tolerance which could be used to improve pearl millet. The objectives of this research were to determine the cytotaxonomic relationship of these two species and to explore the feasibility of interspecific germplasm transfer. Five interspecific hybrids, 2n = 25, with 7 large P. americanum millet (A) and 18 small P. orientale (O) chromosomes were produced by pollinating cytoplasmic male sterile pearl millet with P. orientale pollen. The O chromosomes paired mainly as bivalents and the A chromosomes remained as univalents. A low frequency of AO chromosome associations were observed. Although the possibility of germplasm exchange existed, the two species appeared to be not closely related. Among three hybrids examined, one was a facultative apomict, one was an obligate apomict and another was highly apomictic with 3% of ovules with sexual embryo sacs. Sixteen backcross progenies were established from interspecific hybrids pollinated with pearl millet pollen. Seven plants were 2n = 23 with 14 A + 9 O chromosomes, five were 2n = 27 with 7 A + 20 O chromosomes and four were 2n = 32 with 14 A and 18 O chromosomes. The balanced chromosome number for both species in these latter plants should provide a mechanism for restoring fertility in the interspecific hybrid thus enabling germplasm transfer. The interspecific hybrids were male sterile but set about 1% seed when pollinated with pearl millet pollen.

  1. Apomictic interspecific hybrids between pearl millet and Pennisetum orientale L. C. Rich

    SciTech Connect

    Hanna, W.W.; Dujardin, M.

    1982-07-01

    Pearl millet, Pennisetum americanum (L.) Leeke, is an important world food and forage crop. Pennisetum orientale L.C. Rich. has genes for apomixis, perennial growth habit, pest resistance, and drought tolerance which could be used to improve pearl millet. The objectives of this research were to determine the cytotaxonomic relationship of these two species and to explore the feasibility of interspecific germplasm transfer. Five interspecific hybrids, 2n = 25, with 7 large P. americanum millet (A) and 18 small P. orientale (0) chromosomes were produced by pollinating cytoplasmic male sterile pearl millet with P. orientale pollen. Although the possibility of germplasm exchange existed, the two species appeared to be not closely related. Among three hybrids examined, one was a facultative apomict, one was an obligate apomict and another was highly apomictic with 3% of ovules with sexual embryo sacs. Sixteen backcross progenies were established from interspecific hybrids pollinated with pearl millet pollen. The balanced chromosome number for both species in these latter plants should provide a mechanism for restoring fertility in the interspecific hybrid thus enabling germplasm transfer. The interspecific hybrids were male sterile but set about 1% seed when pollinated with pearl millet pollen.

  2. Higher iron pearl millet (Pennisetum glaucum L.) provides more absorbable iron that is limited by increased polyphenolic content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Our objective was to compare the capacity of iron (Fe) biofortified and standard pearl millet (Pennisetum glaucum L.) to deliver Fe for hemoglobin (Hb) synthesis. Pearl millet is the most widely grown type of millet. It is common primarily in West Africa and the Indian subcontinent, and ...

  3. An Invasive Grass Species Alters Carbon Cycling in Hawaiian Dry Forest

    NASA Astrophysics Data System (ADS)

    Litton, C. M.; Sandquist, D. R.; Cordell, S.

    2004-12-01

    At lower elevations on the leeward side of the island of Hawaii, remnant native forests are heavily invaded by an introduced African bunchgrass, Pennisetum setaceum (fountain grass). Our research is designed to determine the consequences of this invasion for carbon (C) cycling in Hawaiian dry forests. We examined above- and belowground C pools and fluxes in 400 m2 replicated forest plots (n = 4) with fountain grass (grass plots) and in areas where fountain grass had been removed for ˜3 years (removal plots). C pools were estimated with direct sampling and allometric equations developed in situ for the dominant tree species. Aboveground net primary productivity (ANPP) was estimated as aboveground biomass increment plus litterfall minus loss from mortality (trees) and with clip plots (grass and herbaceous species); total belowground carbon allocation (TBCA) was estimated using a conservation of mass, C balance approach. Our results indicate that the invasion of a non-native grass in this ecosystem has considerable impacts on both C pools and fluxes. Aboveground, tree biomass did not differ between treatments (P = 0.57) but the presence of fountain grass led to a 7.5-fold increase in understory biomass in grass plots compared to removal plots (P < 0.01). Tree ANPP was significantly higher in removal plots for both foliage (0.10 and 0.06 kg C m-2 yr-1 for removal and grass plots, respectively; P = 0.02) and wood (0.13 and 0.05 kg C m-2 yr-1 for removal and grass plots, respectively; P < 0.01). However, grass ANPP was ˜35% greater than tree foliage productivity in grass plots. Despite this added foliar productivity, total ANPP (Tree + Grass ANPP) was significantly higher in removal plots (P = 0.04). Belowground, grass plots exhibited higher rates of soil-surface CO2 efflux (1.09 and 1.38 kg C m-2 yr-1 for removal and grass plots, respectively; P = 0.03 ). Likewise, TBCA was significantly higher in grass plots (1.21 kg C m-2 yr-1) than in removal plots (0.97 kg C m-2

  4. Natural enemies of lepidopterous borers on maize and elephant grass in the forest zone of Cameroon.

    PubMed

    Ndemah, R; Schulthess, F; Poehling, M; Borgemeister, C; Goergen, G

    2001-06-01

    The importance, geographical and temporal distributions of parasitoids of lepidopterous borers on maize and elephant grass, Pennisetum purpureum, were assessed during surveys in farmers' fields in six villages and two on-station trials in the forest zone of Cameroon between 1995 and 1996. The borer species encountered were Busseola fusca (Fuller), Sesamia calamistis Hampson, Eldana saccharina Walker on both host plants, and Mussidia nigrivenella Ragonot on maize only. Busseola fusca was the predominant host accounting for 44-57% and 96% on maize and elephant grass, respectively, followed by E. saccharina on maize with 27-39%. Fifteen hymenopterous, two dipterous and one fungal species were found on these stem and cob-borers. Among those were six pupal, six larval, four egg, one larval-pupal parasitoid and four hyperparasitoids. The scelionid parasitoids Telenomus busseolae Gahan and T. isis Polaszek were found on B. fusca eggs in all locations. During the first season, mean egg parasitism was low and ranged between 3.1% and 27% versus 54-87% during the second season. Species belonging to the Tetrastichus atriclavus Waterston complex were recovered from all four borer species. The majority and most common larval and pupal parasitoid species belonged to the ingress-and-sting guild. Larval and pupal parasitism were very erratic and on more than 50% of the sampling occasions no parasitoids were recovered. Parasitoid diversity was higher on elephant grass than maize.

  5. Second-generation ethanol production from elephant grass at high total solids.

    PubMed

    Menegol, Daiane; Fontana, Roselei Claudete; Dillon, Aldo José Pinheiro; Camassola, Marli

    2016-07-01

    The enzymatic hydrolysis of Pennisetum purpureum (elephant grass) was evaluated at high total solid levels (from 4% to 20% (w/v)) in a concomitant ball milling treatment in a rotating hydrolysis reactor (RHR). The greatest glucose yield was 20.17% when 4% (w/v) untreated biomass was employed. When sugars obtained from enzymatic hydrolysis were submitted to fermentation with Saccharomyces cerevisiae, the greatest ethanol yield was 22.61% when 4% (w/v) untreated biomass was employed; however, the highest glucose concentration (12.47g/L) was obtaining using 20% (w/v) solids and highest ethanol concentration (6.1g/L) was obtained using 16% (w/v) solids. When elephant grass was hydrolyzed in the rotating hydrolysis reactor, ethanol production was about double that was produced when the biomass was hydrolyzed in a static reactor (SR). These data indicate that it is possible to produce ethanol from elephant grass when milling treatment and enzymatic hydrolysis are performed at the same time.

  6. Intake and digestion of wethers fed with dwarf elephant grass hay with or without the inclusion of peanut hay.

    PubMed

    Schnaider, Maria Alice; Ribeiro-Filho, Henrique Mendonça Nunes; Vilmar Kozloski, Gilberto; Reiter, Tatiana; Dall Orsoletta, Aline Cristina; Dallabrida, Ademar Luiz

    2014-08-01

    The aim of this study was to evaluate the effect of the inclusion of peanut (Arachis pintoi cv. Amarillo) hay in diets based on dwarf elephant grass (DEG, Pennisetum purpureum Schum cv. Kurumi) hay of different regrowth ages on forage intake and digestibility in wether lambs. The experimental treatments consisted of DEG hay with an interval of regrowth of 30 or 45 days offered as the only feed or in mixture with peanut hay (300 g/kg of total dry matter (DM)), which were tested in eight Texel × Suffolk crossbred wethers in a replicated 4 × 4 Latin square experiment. Both organic matter (OM) and digestible OM intakes were higher (P < 0.05) in animals receiving the legume forage. Total apparent OM digestibility was higher (P < 0.05) at an increased grass regrowth age. Ruminal OM digestibility increased (P < 0.05) with legume inclusion and at a higher grass regrowth age. The nitrogen (N) intake was higher (P < 0.05) in legume treatments and lower (P < 0.05) as the grass regrowth age increased, but retention of N was not affected by treatments. Duodenal flow of both, non-ammonia N and microbial N, were not affected by legume inclusion and were lower (P < 0.05) as grass regrowth age increased. The efficiency of rumen microbial protein synthesis (ERMPS) was negatively affected (P < 0.05) by legume inclusion and was lower (P < 0.05) as the grass regrowth age increased. Supplementation of dwarf elephant grass hay cut at the vegetative stage with peanut legume hay improves nutritional supply to wethers due to an increase in the forage intake.

  7. Grass Roots Project Evaluation.

    ERIC Educational Resources Information Center

    Wick, John W.

    Some aspects of a grass roots evaluation training program are presented. The program consists of two elements: (1) a series of 11 slide/tape individualized self-paced units, and (2) a six-week summer program. Three points of view on this program are: (1) University graduate programs in quantitative areas are usually consumed by specialists; (2)…

  8. Assessment of in situ and ex situ phytorestoration with grass mixtures in soils polluted with nickel, copper, and arsenic

    NASA Astrophysics Data System (ADS)

    Zacarías Salinas, Montserrat; Beltrán Villavicencio, Margarita; Bustillos, Luis Gilberto Torres; González Aragón, Abelardo

    This work shows a study of in situ and ex situ phytoextraction as a polishing step in the treatment of an industrial urban soil polluted with nickel, arsenic and copper. The soil was previously washed, and phytoextraction was performed by application of a mixture of grass (Festuca rubra, Cynodon dactylon, Lolium multiforum, Pennisetum). The soil had initial heavy metals concentrations of 131 ppm for Ni, 717 for As and 2734 for Cu (mg of metal/kg of dry soil). After seeding and emerging of grass, vegetal and soil samples were taken monthly during 4 months. Biomass generation, and concentration of Ni, As and Cu in vegetal tissue and soil were determined for every sample. Plants biomass growth in ex situ process was inhibited by 37% when compared with blank soil. Grass showed remarkable phytoextraction capability in situ, it produced 38 g of biomass every 15 days (wet weight) during a period of 3 months, but then declined in the fourth month. Concentrations of metals in grass biomass were up to 83 mg Ni/kg, 649 mg As/kg and 305 mg Cu/kg dry weight. Metal reduction of 49% for Ni, and 35% for Cu and As was observed at rhizospheric soil.

  9. Algerian pearl millet ( Pennisetum glaucum L.) contains XIP but not TAXI and TLXI type xylanase inhibitors.

    PubMed

    Mokrane, Hind; Gebruers, Kurt; Beaugrand, Johnny; Proost, Paul; Nadjemi, Boubekeur; Belhanèche-Bensemra, Naima; Courtin, Christophe M; Delcour, Jan A

    2009-06-24

    An XIP (xylanase inhibiting protein) type xylanase inhibitor was purified from Algerian pearl millet ( Pennisetum glaucum L.) grains and characterized for the first time. Cation exchange and affinity chromatography with immobilized Trichoderma longibrachiatum glycoside hydrolase (GH) family 11 xylanase resulted in electrophoretically pure protein with a molecular mass of 27-29 kDa and a pI value of 6.7. The experimentally determined N-terminal amino acid sequence of the purified XIP protein is 87.5%, identical to that of sorghum ( Sorghum bicolor L.) XIP and 79.2% identical to that of wheat ( Triticum aestivum L.) XIP-I. The biochemical properties of pearl millet XIP are comparable to those described earlier for sorghum XIP, except for the higher specific activity toward a T. longibrachiatum GH family 11 xylanase. On the basis of immunoblot neither TAXI nor TLXI type xylanase inhibitors were detected in pearl millet grains.

  10. Efficient regeneration of pearl millet (Pennisetum glaucum (L.) R. Br.) from shoot tip cultures.

    PubMed

    Mythili, P K; Madhavi, A; Reddy, V D; Seetharama, N

    2001-12-01

    A simple, genotype-independent and efficient method for plant regeneration using shoot tip explants of pearl millet (Pennisetum glaucum) was established. Linsmaier and Skoog (LS) medium supplemented with 2,4-dichloro-phenoxyacetic acid (2.5 mg l(-1)) and kinetin (0. 2 mg l(-1)) was used for induction of embryogenic calli. Development of numerous somatic embryos was observed within 10 days after transferring onto Murashige and Skoog (MS) medium supplemented with 6-benzyl aminopurine (2 mg l(-1)) and indole 3-butyric acid (0. 5 mg l(-1)) under light (16 hr photoperiod). Histological observations confirmed the origin of somatic pro-embryoids and globular embryoids. Regenerated plants established in soil, grew normally and produced fertile seeds. RAPD analysis also revealed genetic uniformity of the regenerants. The short duration of time taken for regeneration (30-35 days) and its high frequency (78-87%) makes this system highly suitable for applications such as genetic transformation.

  11. Using a high biomass plant Pennisetum hydridum to phyto-treat fresh municipal sewage sludge.

    PubMed

    Hei, Liang; Lee, Charles C C; Wang, Hui; Lin, Xiao-Yan; Chen, Xiao-Hong; Wu, Qi-Tang

    2016-10-01

    The study was carried out to investigate the use of a high biomass plant, Pennisetum hydridum, to treat municipal sewage sludge (MSS). An experiment composed of plots with four treatments, soil, fresh sludge, soil-sludge mixture and phyto-treated sludge, was conducted. It showed that the plant could not survive directly in fresh MSS when cultivated from stem cuttings. The experiment transplanting the incubated cutting with nurse medium of P. hydridum in soil and fresh MSS, showed that the plants grew normally in fresh MSS. The pilot experiment of P. hydridum and Alocasia macrorrhiza showed that the total yield and nutrient amount of P. hydridum were 9.2 times and 3.6 times more than that of A. macrorrhiza. After plant treatment, MSS was dried, stabilized and suitable to be landfilled or incinerated, with a calorific value of about 5.6MJ/kg (compared to the initial value of 1.9MJ/kg fresh sludge).

  12. Inoculation with endophytic Bacillus megaterium H3 increases Cd phytostabilization and alleviates Cd toxicity to hybrid pennisetum in Cd-contaminated aquatic environments.

    PubMed

    Li, Ya; Han, Hui; He, Lin Yan; Wang, Qi; Sheng, Xia Fang

    2017-01-01

    A hydroponic culture experiment was performed to investigate the effects of endophytic Bacillus megaterium H3 on the plant biomass, Cd accumulation and tolerance of hybrid pennisetum, and the mechanisms involved in the different levels of Cd-contaminated aquatic environments. Strain H3 significantly increased the plant growth (ranging from 13 to 71 %) and total Cd uptake (ranging from 41 to 160 %) but decreased Cd translocation factors of hybrid pennisetum treated with 0-20 μM Cd compared with the controls. Furthermore, most of Cd (71-77 %) was accumulated in the roots of the bacterial-inoculated hybrid pennisetum. Notably, strain H3 could significantly increase the production of oxalic and propanedioic acids (ranging from 18 to 188 %) but decrease the production of phytochelatins of hybrid pennisetum compared to the controls under different levels of Cd stress. The live bacterial-induced increase in organic acid production and decrease in phytochelatins production by hybrid pennisetum might be responsible for the increased plant growth, root Cd accumulation, and Cd toxicity alleviation of the plant under different levels of Cd stress. The results highlight that hybrid pennisetum plus endophytic B. megaterium H3 may be utilized for biomass production and Cd phytostabilization of the plant in the different levels of Cd-contaminated aquatic environments.

  13. Waving of Aquatic Grasses

    NASA Astrophysics Data System (ADS)

    Mahadevan, A.; Richards, K.

    2004-05-01

    We examine the fluid-structure interaction between submerged flexible grass stems and unidirectional flow in a channel. The stems deform in response to the drag force imposed by the flow. The drag, however, varies non-linearly with the fluid velocity and it's angle of incidence with the stems' axis. An increase in fluid velocity increases drag that consequently decelerates the fluid, but also bends the stems further and reduces drag. Such a drag-induced feedback mechanism between the plant structures and water results in an instability that is responsible for the synchronous waving of aquatic grasses in a flow field that is initially uniform. We construct a model for this phenomenon to explore its dependence on parameters. Experiments are also in progress. We further propose to test the applicability of similar mechanisms to sediment transport over deformable beds.

  14. Attacking invasive grasses

    USGS Publications Warehouse

    Keeley, Jon E.

    2015-01-01

    In grasslands fire may play a role in the plant invasion process, both by creating disturbances that potentially favour non-native invasions and as a possible tool for controlling alien invasions. Havill et al. (Applied Vegetation Science, 18, 2015, this issue) determine how native and non-native species respond to different fire regimes as a first step in understanding the potential control of invasive grasses.

  15. Implications of biomass pretreatment to cost and carbon emissions: case study of rice straw and Pennisetum in Taiwan.

    PubMed

    Chiueh, Pei-Te; Lee, Kun-Chou; Syu, Fu-Sians; Lo, Shang-Lien

    2012-03-01

    The purpose of this study was to explore the impact of feedstock collection and torrefaction pretreatment on the efficiency of a biomass co-firing system. Considering the transformation of existing municipal solid waste incinerators, several scenarios in which biomass supply chains depend on centralised pretreatment and transportation alternatives are presented. The cost, net energy output, and greenhouse gas effects of these scenarios were analysed using a spreadsheet model. Based on the Taoyuan County case in Taiwan, the mitigation costs of carbon emissions for rice straw and Pennisetum are 77.0 $/Mg CO(2) and 63.8 $/Mg CO(2), respectively. Results indicate that transporting feedstock from its source to the pretreatment and co-firing stations contributes the most to logistical costs for both straw and Pennisetum, regardless of whether torrefaction was adopted. Nonetheless, torrefaction requires more demonstrated cases at various scales to obtain the technical and economic data required for further analysis.

  16. Phylogenetic studies favour the unification of Pennisetum, Cenchrus and Odontelytrum (Poaceae): a combined nuclear, plastid and morphological analysis, and nomenclatural combinations in Cenchrus

    PubMed Central

    Chemisquy, M. Amelia; Giussani, Liliana M.; Scataglini, María A.; Kellogg, Elizabeth A.; Morrone, Osvaldo

    2010-01-01

    Backgrounds and Aims Twenty-five genera having sterile inflorescence branches were recognized as the bristle clade within the x = 9 Paniceae (Panicoideae). Within the bristle clade, taxonomic circumscription of Cenchrus (20–25 species), Pennisetum (80–140) and the monotypic Odontelytrum is still unclear. Several criteria have been applied to characterize Cenchrus and Pennisetum, but none of these has proved satisfactory as the diagnostic characters, such as fusion of bristles in the inflorescences, show continuous variation. Methods A phylogenetic analysis based on morphological, plastid (trnL-F, ndhF) and nuclear (knotted) data is presented for a representative species sampling of the genera. All analyses were conducted under parsimony, using heuristic searches with TBR branch swapping. Branch support was assessed with parsimony jackknifing. Key Results Based on plastid and morphological data, Pennisetum, Cenchrus and Odontelytrum were supported as a monophyletic group: the PCO clade. Only one section of Pennisetum (Brevivalvula) was supported as monophyletic. The position of P. lanatum differed among data partitions, although the combined plastid and morphology and nuclear analyses showed this species to be a member of the PCO clade. The basic chromosome number x = 9 was found to be plesiomorphic, and x = 5, 7, 8, 10 and 17 were derived states. The nuclear phylogenetic analysis revealed a reticulate pattern of relationships among Pennisetum and Cenchrus, suggesting that there are at least three different genomes. Because apomixis can be transferred among species through hybridization, its history most likely reflects crossing relationships, rather than multiple independent appearances. Conclusions Due to the consistency between the present results and different phylogenetic hypotheses (including morphological, developmental and multilocus approaches), and the high support found for the PCO clade, also including the type species of the three genera, we propose

  17. GRASS Hardware Configurations Guide

    DTIC Science & Technology

    1989-03-01

    portability rather than limit users to a single brand of hardware. Within GRASS, there are many processor inten- sive functions. Therefore, processor...Expansion Unit 2,000 558 RR13 2 60 MB. 1 4V tape drive 1.233 SYSI,2 2-User Licene N, C Total $ 26,710 $ 23,290 IhLs erem is not supplij, bv ,un Nficrosyterms...DOS world there are a ’arge number of vendors that can supply you with the basic 386 personal computer that wili work in place of the brand of computer

  18. Ornamental Landscape Grasses. Slide Script.

    ERIC Educational Resources Information Center

    Still, Steven M.; Adams, Denise W.

    This slide script to accompany the slide series, Ornamental Landscape Grasses, contains photographs of the 167 slides and accompanying narrative text intended for use in the study and identification of commercially important ornamental grasses and grasslike plants. Narrative text is provided for slides of 62 different perennial and annual species…

  19. Changes in soil bacterial communities induced by the invasive plant Pennisetum setaceum in a semiarid environment

    NASA Astrophysics Data System (ADS)

    Rodriguez-Caballero, Gema; Caravaca, Fuensanta; del Mar Alguacil, María; Fernández-López, Manuel; José Fernández-González, Antonio; García-Orenes, Fuensanta; Roldán, Antonio

    2016-04-01

    Invasive alien species are considered as a global threat being among the main causes of biodiversity loss. Plant invasions have been extensively studied from different disciplines with the purpose of identifying predictor traits of invasiveness and finding solutions. However, less is known about the implication of the rhizosphere microbiota in these processes, even when it is well known the importance of the interaction between plant rhizosphere and microbial communities. The objective of this study was to determine whether native and invasive plants support different bacterial communities in their rhizospheres and whether there are bacterial indicator species that might be contributing to the invasion process of these ecosystems. We carried out a study in five independent locations under Mediterranean semiarid conditions, where the native Hyparrhenia hirta is being displaced by Pennisetum setaceum, an aggressive invasive Poaceae and soil bacterial communities were amplified and 454-pyrosequenced. Changes in the composition and structure of the bacterial communities, owing to the invasive status of the plant, were detected when the richness and alpha-diversity estimators were calculated as well as when we analyzed the PCoA axes scores. The Indicator Species Analysis results showed a higher number of indicators for invaded communities at all studied taxonomic levels. In conclusion, the effect of the invasiveness and its interaction with the soil location has promoted shifts in the rhizosphere bacterial communities which might be facilitating the invader success in these ecosystems.

  20. The effects of additives in napier grass silages on chemical composition, feed intake, nutrient digestibility and rumen fermentation.

    PubMed

    Bureenok, Smerjai; Yuangklang, Chalermpon; Vasupen, Kraisit; Schonewille, J Thomas; Kawamoto, Yasuhiro

    2012-09-01

    The effect of silage additives on ensiling characteristics and nutritive value of Napier grass (Pennisetum purpureum) silages was studied. Napier grass silages were made with no additive, fermented juice of epiphytic lactic acid bacteria (FJLB), molasses or cassava meal. The ensiling characteristics were determined by ensiling Napier grass silages in airtight plastic pouches for 2, 4, 7, 14, 21 and 45 d. The effect of Napier grass silages treated with these additives on voluntary feed intake, digestibility, rumen fermentation and microbial rumen fermentation was determined in 4 fistulated cows using 4×4 Latin square design. The pH value of the treated silages rapidly decreased, and reached to the lowest value within 7 d of the start of fermentation, as compared to the control. Lactic acid content of silages treated with FJLB was stable at 14 d of fermentation and constant until 45 d of ensiling. At 45 d of ensiling, neutral detergent fiber (NDF) and acid detergent fiber (ADF) of silage treated with cassava meal were significantly lower (p<0.05) than the others. In the feeding trial, the intake of silage increased (p<0.05) in the cow fed with the treated silage. Among the treatments, dry matter intake was the lowest in the silage treated with cassava meal. The organic matter, crude protein and NDF digestibility of the silage treated with molasses was higher than the silage without additive and the silage treated with FJLB. The rumen parameters: ruminal pH, ammonia-nitrogen (NH3-N), volatile fatty acid (VFA), blood urea nitrogen (BUN) and bacterial populations were not significantly different among the treatments. In conclusion, these studies confirmed that the applying of molasses improved fermentative quality, feed intake and digestibility of Napier grass.

  1. Extending juvenility in grasses

    DOEpatents

    Kaeppler, Shawn; de Leon Gatti, Natalia; Foerster, Jillian

    2017-04-11

    The present invention relates to compositions and methods for modulating the juvenile to adult developmental growth transition in plants, such as grasses (e.g. maize). In particular, the invention provides methods for enhancing agronomic properties in plants by modulating expression of GRMZM2G362718, GRMZM2G096016, or homologs thereof. Modulation of expression of one or more additional genes which affect juvenile to adult developmental growth transition such as Glossy15 or Cg1, in conjunction with such modulation of expression is also contemplated. Nucleic acid constructs for down-regulation of GRMZM2G362718 and/or GRMZM2G096016 are also contemplated, as are transgenic plants and products produced there from, that demonstrate altered, such as extended juvenile growth, and display associated phenotypes such as enhanced yield, improved digestibility, and increased disease resistance. Plants described herein may be used, for example, as improved forage or feed crops or in biofuel production.

  2. Equine grass sickness.

    PubMed

    Pirie, R S; Jago, R C; Hudson, N P H

    2014-09-01

    Equine grass sickness (EGS; equine dysautonomia) is a polyneuronopathy affecting both the central and the peripheral nervous systems of horses. As the name implies, EGS almost exclusively affects grazing horses, resulting in the development of a characteristic array of clinical signs, most of which can be attributed to neuronal degeneration in the autonomic and enteric nervous systems. Varying disease severities occur, largely determined by the extent of neuronal degeneration in the myenteric and submucous plexuses of the enteric nervous system. Extensive neuronal degeneration, as seen in acute and subacute forms of EGS, results in intestinal dysmotility, the severity of which is incompatible with survival. In comparison, a proportion of chronic forms of EGS, characterised by less severe neuronal degeneration, will survive. Despite extensive research efforts since EGS was first reported over 100 years ago, the precise aetiology remains elusive. This article reviews much of the scientific literature on EGS, covering epidemiology, pathology, diagnosis, treatment and aetiological hypotheses.

  3. Identification of genes differentially expressed during apomictic and sexual development in buffelgrass (Pennisetum ciliare)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apomixis, an asexual method of reproduction through seeds with the absence of meiosis and fertilization holds great potential for plant breeding and hybrid seed production. Buffelgrass, an apomictic forage grass, has well characterized apomictic, facultative and sexual accessions to study apomictic...

  4. Grass fungal endophytes and uses thereof

    DOEpatents

    Craven, Kelly

    2015-03-10

    The invention provides isolated fungal endophytes and synthetic combinations thereof with host grass plants. Methods for inoculating grass plant with the endophytes, for propagating the grass-endophyte combinations, and for producing feeds and biofuels from grass-endophyte combinations are also provided.

  5. Responses of Sorghum and Pennisetum Species to the N2-Fixing Bacterium Azospirillum brasilense†

    PubMed Central

    Smith, Rex L.; Schank, S. C.; Milam, J. R.; Baltensperger, A. A.

    1984-01-01

    Three field inoculation experiments, two in Florida and one in New Mexico, were conducted with Azospirillum brasilense Cd. Each of the Florida experiments evaluated two crop species. One species in each of the Florida experiments responded to inoculation with a significant dry matter yield increases of 11 to 24% and nitrogen yield increases of 9 to 39%. No inoculation response was noted in the New Mexico experiment. The responding species were Sorghum bicolor (L.) Moench (sorghum) and the interspecific hybrid between Pennisetum americanum (L.) K. Schum. (pearl millet) and P. purpureum Schumach. (napiergrass). Nonresponding species were pearl millet (Florida) and Sorghum sudanense (Piper) Staph. (New Mexico). Acetylene reduction activity of inoculated plots in Florida was low, showing no increase over the natural uninoculated background rates and, in one case, was negatively correlated with yield. Acetylene reduction activity was not measured in New Mexico. In Florida, A. brasilense populations were found to decline from 5 × 103 to 5 × 102 bacteria g of soil−1 in about 3 weeks (quadratic regressions). Continued decline to less than 102 by week 5 indicated that the inoculated bacteria did not become established in the soil in high numbers. The A. brasilense population declined at about the same rate in the New Mexico experiment. The erractic inoculation responses in these experiments are similar to those observed in earlier work at the University of Florida. The lack of acetylene reduction activity response to inoculation and the rapid population decline of the inoculated bacteria suggest that N2 fixation is not the major mechanism causing yield responses after inoculation. PMID:16346571

  6. Reproduction of Belonolaimus longicaudatus, Meloidogyne javanica, Paratrichodorus minor, and Pratylenchus brachyurus on Pearl Millet (Pennisetum glaucum)

    PubMed Central

    Timper, P.; Hanna, W. W.

    2005-01-01

    Pearl millet (Pennisetum glaucum) has potential as a grain crop for dryland crop production in the southeastern United States. Whether or not pearl millet will be compatible in rotation with cotton (Gossypium hirsutum), corn (Zea mays), and peanut (Arachis hypogaea) will depend, in part, on its host status for important plant-parasitic nematodes of these crops. The pearl millet hybrid 'TifGrain 102' is resistant to both Meloidogyne incognita race 3 and M. arenaria race 1; however, its host status for other plant-parasitic nematodes was unknown. In this study, the reproduction of Belonolaimus longicaudatus, Paratrichodorus minor, Pratylenchus brachyurus, and Meloidogyne javanica race 3 on pearl millet ('HGM-100' and TifGrain 102) was compared relative to cotton, corn, and peanut. Separate greenhouse experiments were conducted for each nematode species. Reproduction of B. longicaudatus was lower on peanut and the two millet hybrids than on cotton and corn. Reproduction of P. minor was lower on peanut and TifGrain 102 than on cotton, corn, and HGM-100. Reproduction of P. brachyurus was lower on both millet hybrids than on cotton, corn, and peanut. Reproduction of M. javanica race 3 was greater on peanut than on the two millet hybrids and corn. Cotton was a nonhost. TifGrain 102 was more resistant than HGM-100 to reproduction of B. longicaudatus, P. minor, and M. javanica. Our results demonstrated that TifGrain 102 was a poor host for B. longicaudatus and P. brachyurus (Rf < 1) and, relative to other crops tested, was less likely to increase densities of P. minor and M. javanica. PMID:19262863

  7. Dune Grass Fertilization and Maintenance

    DTIC Science & Technology

    1982-12-01

    plants often suffer, thereafter, from neglect. PURPOSE: To recommend a fertilization and maintenance program to sustain healthy dune grasses in coastal...TYPE 3. DATES COVERED 00-00-1982 to 00-00-1982 4. TITLE AND SUBTITLE Dune Grass Fertilization and Maintenance 5a. CONTRACT NUMBER 5b. GRANT...TO APPLY: Apply a granular or pelletized agricultural type fertilizer . It need not be a costly, slow- release material. A.t\\!OUNT OF FERTILIZER TO

  8. Grass Pollen Allergens

    PubMed Central

    Augustin, Rosa

    1959-01-01

    Grass pollen allergens are shown to remain associated with protein material and a yellow pigment during paper chromatography and during dialyses and ultrafiltrations of various types. Dialysable* allergens comprise only a fraction of 1 per cent of the total activity and the amount of activity extractable by diethylene glycol (DEG) and similar solvents is of the same order. Besides the allergens, the DEG and aqueous extracts contain large amounts of inositol, glucose and fructose, also some yellow pigments and phosphates. Larger amounts of free and combined amino acids are found in the aqueous than in the DEG extracts, but the reverse is true for sucrose. In addition the DEG extracts contain a yellow glucoside different from the dactylen of the aqueous extracts, a glucosan and an arabinose-galactose-pigment complex, only the latter being associated with any activity. The spontaneous release of the crystalline dactylen from originally clear aqueous pollen extracts is found not to be caused by enzymes. The washed crystals are found to be chromatographically and electrophoretically homogeneous and devoid of allergenic activity. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7 PMID:13640676

  9. Effect of energy grass on methane production and heavy metal fractionation during anaerobic digestion of sewage sludge.

    PubMed

    Zhang, Min; Yang, Changming; Jing, Yachao; Li, Jianhua

    2016-12-01

    Anaerobic digestion (AD) is one of the most widely used processes to stabilize waste sewage sludge and produce biogas as renewable energy. The relatively low organic matter content and high heavy metal concentrations in sewage sludge have severely restricted the application and development of AD technology in China. In this study, the effect of energy grass (Pennisetum alopecuroides) addition on methane production and heavy metal fractionation during the AD of sewage sludge was evaluated. Methane production was enhanced by 11.2% by the addition of P. alopecuroides. The addition of P. alopecuroides significantly reduced the percentages of the water-soluble and exchangeable fractions of the target heavy metals in the sewage sludge after AD, and the dominant species were concentrated in Fe-Mn oxide-bound and organic- and sulfide-bound fractions of the digested sludge. The addition of P. alopecuroides at a dosage of 0.3kg significantly (P<0.05) decreased the mobility factors (MFs) of the target heavy metals after AD. In particular, the MFs of Cr and Ni were 61% and 32% lower, respectively, relative to the control. The increase in the added dose did not necessarily lead to further decreases in the MFs of the heavy metals. These results demonstrate that an appropriate addition of energy grass could enhance AD, decrease the mobility of heavy metals and promote heavy metal stabilization in sewage sludge during AD, which is beneficial for the subsequent land application of sewage sludge.

  10. Molecular Evolution of Grass Stomata.

    PubMed

    Chen, Zhong-Hua; Chen, Guang; Dai, Fei; Wang, Yizhou; Hills, Adrian; Ruan, Yong-Ling; Zhang, Guoping; Franks, Peter J; Nevo, Eviatar; Blatt, Michael R

    2017-02-01

    Grasses began to diversify in the late Cretaceous Period and now dominate more than one third of global land area, including three-quarters of agricultural land. We hypothesize that their success is likely attributed to the evolution of highly responsive stomata capable of maximizing productivity in rapidly changing environments. Grass stomata harness the active turgor control mechanisms present in stomata of more ancient plant lineages, maximizing several morphological and developmental features to ensure rapid responses to environmental inputs. The evolutionary development of grass stomata appears to have been a gradual progression. Therefore, understanding the complex structures, developmental events, regulatory networks, and combinations of ion transporters necessary to drive rapid stomatal movement may inform future efforts towards breeding new crop varieties.

  11. Fermentation Characteristics and Microbial Diversity of Tropical Grass-legumes Silages.

    PubMed

    Ridwan, Roni; Rusmana, Iman; Widyastuti, Yantyati; Wiryawan, Komang G; Prasetya, Bambang; Sakamoto, Mitsuo; Ohkuma, Moriya

    2015-04-01

    Calliandra calothyrsus preserved in silage is an alternative method for improving the crude protein content of feeds for sustainable ruminant production. The aim of this research was to evaluate the quality of silage which contained different levels of C. calothyrsus by examining the fermentation characteristics and microbial diversity. Silage was made in a completely randomized design consisting of five treatments with three replications i.e.: R0, Pennisetum purpureum 100%; R1, P. purpureum 75%+C. calothyrsus 25%;, R2, P. purpureum 50%+C. calothyrsus 50%; R3, P. purpureum 25%+C. calothyrsus 75%; and R4, C. calothyrsus 100%. All silages were prepared using plastic jar silos (600 g) and incubated at room temperature for 30 days. Silages were analyzed for fermentation characteristics and microbial diversity. Increased levels of C. calothyrsus in silage had a significant effect (p<0.01) on the fermentation characteristics. The microbial diversity index decreased and activity was inhibited with increasing levels of C. calothyrsus. The microbial community indicated that there was a population of Lactobacillus plantarum, L. casei, L. brevis, Lactococcus lactis, Chryseobacterium sp., and uncultured bacteria. The result confirmed that silage with a combination of grass and C. calothyrsus had good fermentation characteristics and microbial communities were dominated by L. plantarum.

  12. Assessment of Bermudagrass and Bunch Grasses as Feedstock for Conversion to Ethanol

    NASA Astrophysics Data System (ADS)

    Anderson, William F.; Dien, Bruce S.; Brandon, Sarah K.; Peterson, Joy Doran

    Research is needed to allow more efficient processing of lignocellulose from abundant plant biomass resources for production to fuel ethanol at lower costs. Potential dedicated feedstock species vary in degrees of recalcitrance to ethanol processing. The standard dilute acid hydrolysis pretreatment followed by simultaneous sacharification and fermentation (SSF) was performed on leaf and stem material from three grasses: giant reed (Arundo donax L.), napiergrass (Pennisetum purpureum Schumach.), and bermudagrass (Cynodon spp). In a separate study, napiergrass, and bermudagrass whole samples were pretreated with esterase and cellulose before fermentation. Conversion via SSF was greatest with two bermudagrass cultivars (140 and 122 mg g-1 of biomass) followed by leaves of two napiergrass genotypes (107 and 97 mg g-1) and two giant reed clones (109 and 85 mg g-1). Variability existed among bermudagrass cultivars for conversion to ethanol after esterase and cellulase treatments, with Tifton 85 (289 mg g) and Coastcross II (284 mg g-1) being superior to Coastal (247 mg g-1) and Tifton 44 (245 mg g-1). Results suggest that ethanol yields vary significantly for feedstocks by species and within species and that genetic breeding for improved feedstocks should be possible.

  13. Fermentation Characteristics and Microbial Diversity of Tropical Grass-legumes Silages

    PubMed Central

    Ridwan, Roni; Rusmana, Iman; Widyastuti, Yantyati; Wiryawan, Komang G.; Prasetya, Bambang; Sakamoto, Mitsuo; Ohkuma, Moriya

    2015-01-01

    Calliandra calothyrsus preserved in silage is an alternative method for improving the crude protein content of feeds for sustainable ruminant production. The aim of this research was to evaluate the quality of silage which contained different levels of C. calothyrsus by examining the fermentation characteristics and microbial diversity. Silage was made in a completely randomized design consisting of five treatments with three replications i.e.: R0, Pennisetum purpureum 100%; R1, P. purpureum 75%+C. calothyrsus 25%;, R2, P. purpureum 50%+C. calothyrsus 50%; R3, P. purpureum 25%+C. calothyrsus 75%; and R4, C. calothyrsus 100%. All silages were prepared using plastic jar silos (600 g) and incubated at room temperature for 30 days. Silages were analyzed for fermentation characteristics and microbial diversity. Increased levels of C. calothyrsus in silage had a significant effect (p<0.01) on the fermentation characteristics. The microbial diversity index decreased and activity was inhibited with increasing levels of C. calothyrsus. The microbial community indicated that there was a population of Lactobacillus plantarum, L. casei, L. brevis, Lactococcus lactis, Chryseobacterium sp., and uncultured bacteria. The result confirmed that silage with a combination of grass and C. calothyrsus had good fermentation characteristics and microbial communities were dominated by L. plantarum. PMID:25656192

  14. Chemicals Reduce Need To Mow Grass

    NASA Technical Reports Server (NTRS)

    Humphrys, Brooks; Farley, Max; Gast, Larry J.

    1993-01-01

    Brief report discusses use of herbicides Roundup(R), Campaign(R), and Oust(R) to retard growth of Argentine bahia grass. Herbicide applied by use of spraying apparatus pulled by tractor. "Chemical mowing" keeps grass at "freshly mowed" height with less mechanical mowing. Applied to grass on shoulders of roads, reducing time spent on mowing.

  15. Grass pollen allergens globally: the contribution of subtropical grasses to burden of allergic respiratory diseases.

    PubMed

    Davies, J M

    2014-06-01

    Grass pollens of the temperate (Pooideae) subfamily and subtropical subfamilies of grasses are major aeroallergen sources worldwide. The subtropical Chloridoideae (e.g. Cynodon dactylon; Bermuda grass) and Panicoideae (e.g. Paspalum notatum; Bahia grass) species are abundant in parts of Africa, India, Asia, Australia and the Americas, where a large and increasing proportion of the world's population abide. These grasses are phylogenetically and ecologically distinct from temperate grasses. With the advent of global warming, it is conceivable that the geographic distribution of subtropical grasses and the contribution of their pollen to the burden of allergic rhinitis and asthma will increase. This review aims to provide a comprehensive synthesis of the current global knowledge of (i) regional variation in allergic sensitivity to subtropical grass pollens, (ii) molecular allergenic components of subtropical grass pollens and (iii) allergic responses to subtropical grass pollen allergens in relevant populations. Patients from subtropical regions of the world show higher allergic sensitivity to grass pollens of Chloridoideae and Panicoideae grasses, than to temperate grass pollens. The group 1 allergens are amongst the allergen components of subtropical grass pollens, but the group 5 allergens, by which temperate grass pollen extracts are standardized for allergen content, appear to be absent from both subfamilies of subtropical grasses. Whilst there are shared allergenic components and antigenic determinants, there are additional clinically relevant subfamily-specific differences, at T- and B-cell levels, between pollen allergens of subtropical and temperate grasses. Differential immune recognition of subtropical grass pollens is likely to impact upon the efficacy of allergen immunotherapy of patients who are primarily sensitized to subtropical grass pollens. The literature reviewed herein highlights the clinical need to standardize allergen preparations for both

  16. UV induced visual cues in grasses

    PubMed Central

    Baby, Sabulal; Johnson, Anil John; Govindan, Balaji; Lukose, Sujith; Gopakumar, Bhaskaran; Koshy, Konnath Chacko

    2013-01-01

    Grasses are traditionally considered as wind pollinated, however, field observations confirmed frequent insect visits to grass flowers, suggesting insect pollination. Fruit and seed predators inflict heavy losses to cereals and millets during their growth, maturation and storage. The actual factors guiding insects and predators to grass flowers, fruits and seeds are not clear. Here, we report attractive blue fluorescence emissions on grass floral parts such as glumes, lemma, palea, lodicules, staminal filaments, pollens and fruits in ultraviolet (UV) 366 nm, whereas the stigmatic portions were not blue, but red fluorescent. We characterized the blue fluorescent constituent in grass reproductive structures as ferulic acid (FA). Fluorescence spectra of blue-emitting grass floral, seed extracts and isolated FA on excitation at 366 nm showed their emissions at 420–460 nm. We propose these FA-based blue fluorescence emissions in grass reproductive structures as visual cues that attract pollinators, predators and even pests towards them. PMID:24061408

  17. Multiple grass mixes as opposed to single grasses for allergen immunotherapy in allergic rhinitis.

    PubMed

    Gangl, K; Niederberger, V; Valenta, R

    2013-11-01

    Grass pollen allergy affects approximately 40% of allergic patients. Subcutaneous allergen immunotherapy (SCIT) is the only allergen-specific and disease-modifying treatment available. Currently available therapeutic vaccines for the treatment of grass pollen allergy are based on natural grass pollen extracts which are either made from pollen of one cross-reactive grass species or from several related grass species. Clinical studies have shown that SCIT performed with timothy grass pollen extract is effective for the treatment of grass pollen allergy. Moreover, it has been demonstrated that recombinant timothy grass pollen allergens contain the majority of relevant epitopes and can be used for SCIT in clinical trials. However, recent in vitro studies have suggested that mixes consisting of allergen extracts from several related grass species may have advantages for SCIT over single allergen extracts. Here, we review current knowledge regarding the disease-relevant allergens in grass pollen allergy, available clinical studies comparing SCIT with allergen extracts from timothy grass or from mixes of several related grass species of the Pooideae subfamily, in vitro cross-reactivity studies performed with natural allergen extracts and recombinant allergens and SCIT studies performed with recombinant timothy grass pollen allergens. In vitro and clinical studies performed with natural allergen extracts reveal no relevant advantages of using multiple grass mixes as opposed to single grass pollen extracts. Several studies analysing the molecular composition of natural allergen extracts and the molecular profile of patients' immune responses after SCIT with allergen extracts indicate that the major limitation for the production of a high quality grass pollen vaccine resides in intrinsic features of natural allergen extracts which can only be overcome with recombinant allergen-based technologies.

  18. L-band radar scattering from grass

    NASA Technical Reports Server (NTRS)

    Chauhan, N.; O'Neill, P.; Le Vine, D.; Lang, R.; Khadr, N.

    1992-01-01

    A radar system based on a network analyzer has been developed to study the backscatter from vegetation. The radar is operated at L-band. Radar measurements of a grass field were made in 1991. The radar returns from the grass were measured at three incidence angles. Ground truth and canopy parameters such as blade and stem dimensions, moisture content of the grass and the soil, and blade and stem density, were measured. These parameters are used in a distorted Born approximation model to compute the backscatter coefficients from the grass layer. The model results are compared with the radar data.

  19. Checklist of Serengeti Ecosystem Grasses.

    PubMed

    Williams, Emma Victoria; Elia Ntandu, John; Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution.

  20. Checklist of Serengeti Ecosystem Grasses

    PubMed Central

    Ficinski, Paweł; Vorontsova, Maria

    2016-01-01

    Abstract We present the first taxonomic checklist of the Poaceae species of the Serengeti, Tanzania. A review of the literature and herbarium specimens recorded 200 species of grasses, in line with similar studies in other parts of East Africa. The checklist is supported by a total of 939 herbarium collections. Full georeferenced collection data is made available alongside a summary checklist in pdf format. More than a quarter of the species are known from a single collection highlighting the need for further research, especially concerning the rare species and their distribution. PMID:27226761

  1. Soil, vegetation, and seed bank of a Sonoran Desert ecosystem along an exotic plant (Pennisetum ciliare) treatment gradient.

    PubMed

    Abella, Scott R; Chiquoine, Lindsay P; Backer, Dana M

    2013-10-01

    Ecological conditions following removal of exotic plants are a key part of comprehensive environmental management strategies to combat exotic plant invasions. We examined ecological conditions following removal of the management-priority buffelgrass (Pennisetum ciliare) in Saguaro National Park of the North American Sonoran Desert. We assessed soil, vegetation, and soil seed banks on seven buffelgrass site types: five different frequencies of buffelgrass herbicide plus hand removal treatments (ranging from 5 years of annual treatment to a single year of treatment), untreated sites, and non-invaded sites, with three replicates for each of the seven site types. The 22 measured soil properties (e.g., pH) differed little among sites. Regarding vegetation, buffelgrass cover was low (≤1% median cover), or absent, across all treated sites but was high (10-70%) in untreated sites. Native vegetation cover, diversity, and composition were indistinguishable across site types. Species composition was dominated by native species (>93% relative cover) across all sites except untreated buffelgrass sites. Most (38 species, 93%) of the 41 species detected in soil seed banks were native, and native seed density did not differ significantly across sites. Results suggest that: (1) buffelgrass cover was minimal across treated sites; (2) aside from high buffelgrass cover in untreated sites, ecological conditions were largely indistinguishable across sites; (3) soil seed banks harbored ≥12 species that were frequent in the aboveground vegetation; and (4) native species dominated post-treatment vegetation composition, and removing buffelgrass did not result in replacement by other exotic species.

  2. Soil, Vegetation, and Seed Bank of a Sonoran Desert Ecosystem Along an Exotic Plant ( Pennisetum ciliare) Treatment Gradient

    NASA Astrophysics Data System (ADS)

    Abella, Scott R.; Chiquoine, Lindsay P.; Backer, Dana M.

    2013-10-01

    Ecological conditions following removal of exotic plants are a key part of comprehensive environmental management strategies to combat exotic plant invasions. We examined ecological conditions following removal of the management-priority buffelgrass ( Pennisetum ciliare) in Saguaro National Park of the North American Sonoran Desert. We assessed soil, vegetation, and soil seed banks on seven buffelgrass site types: five different frequencies of buffelgrass herbicide plus hand removal treatments (ranging from 5 years of annual treatment to a single year of treatment), untreated sites, and non-invaded sites, with three replicates for each of the seven site types. The 22 measured soil properties (e.g., pH) differed little among sites. Regarding vegetation, buffelgrass cover was low (≤1 % median cover), or absent, across all treated sites but was high (10-70 %) in untreated sites. Native vegetation cover, diversity, and composition were indistinguishable across site types. Species composition was dominated by native species (>93 % relative cover) across all sites except untreated buffelgrass sites. Most (38 species, 93 %) of the 41 species detected in soil seed banks were native, and native seed density did not differ significantly across sites. Results suggest that: (1) buffelgrass cover was minimal across treated sites; (2) aside from high buffelgrass cover in untreated sites, ecological conditions were largely indistinguishable across sites; (3) soil seed banks harbored ≥12 species that were frequent in the aboveground vegetation; and (4) native species dominated post-treatment vegetation composition, and removing buffelgrass did not result in replacement by other exotic species.

  3. The Challenges and Opportunities Associated with Biofortification of Pearl Millet (Pennisetum glaucum) with Elevated Levels of Grain Iron and Zinc.

    PubMed

    Manwaring, Hanna R; Bligh, H F J; Yadav, Rattan

    2016-01-01

    Deficiencies of essential micronutrients such as iron and zinc are the cause of extensive health problems in developing countries. They adversely affect performance, productivity and are a major hindrance to economic development. Since many people who suffer from micronutrient deficiencies are dependent on staple crops to meet their dietary requirements, the development of crop cultivars with increased levels of micronutrients in their edible parts is becoming increasingly recognized as a sustainable solution. This is largely facilitated by genetics and genomic platforms. The cereal crop pearl millet (Pennisetum glaucum), is an excellent candidate for genetic improvement due to its ability to thrive in dry, semi-arid regions, where farming conditions are often unfavorable. Not only does pearl millet grow in areas where other crops such as maize and wheat do not survive, it contains naturally high levels of micronutrients, proteins and a myriad of other health benefitting characteristics. This review discusses the current status of iron and zinc deficiencies and reasons why interventions such as fortification, supplementation, and soil management are neither practicable nor affordable in poverty stricken areas. We argue that the most cost effective, sustainable intervention strategy is to biofortify pearl millet with enhanced levels of bioavailable iron and zinc. We discuss how naturally occurring genetic variations present in germplasm collections can be incorporated into elite, micronutrient rich varieties and what platforms are available to drive this research. We also consider the logistics of transgenic methods that could facilitate the improvement of the pearl millet gene pool.

  4. High-resolution physical mapping in Pennisetum squamulatum reveals extensive chromosomal heteromorphism of the genomic region associated with apomixis.

    PubMed

    Akiyama, Yukio; Conner, Joann A; Goel, Shailendra; Morishige, Daryl T; Mullet, John E; Hanna, Wayne W; Ozias-Akins, Peggy

    2004-04-01

    Gametophytic apomixis is asexual reproduction as a consequence of parthenogenetic development of a chromosomally unreduced egg. The trait leads to the production of embryos with a maternal genotype, i.e. progeny are clones of the maternal plant. The application of the trait in agriculture could be a tremendous tool for crop improvement through conventional and nonconventional breeding methods. Unfortunately, there are no major crops that reproduce by apomixis, and interspecific hybridization with wild relatives has not yet resulted in commercially viable germplasm. Pennisetum squamulatum is an aposporous apomict from which the gene(s) for apomixis has been transferred to sexual pearl millet by backcrossing. Twelve molecular markers that are linked with apomixis coexist in a tight linkage block called the apospory-specific genomic region (ASGR), and several of these markers have been shown to be hemizygous in the polyploid genome of P. squamulatum. High resolution genetic mapping of these markers has not been possible because of low recombination in this region of the genome. We now show the physical arrangement of bacterial artificial chromosomes containing apomixis-linked molecular markers by high resolution fluorescence in situ hybridization on pachytene chromosomes. The size of the ASGR, currently defined as the entire hemizygous region that hybridizes with apomixis-linked bacterial artificial chromosomes, was estimated on pachytene and mitotic chromosomes to be approximately 50 Mbp (a quarter of the chromosome). The ASGR includes highly repetitive sequences from an Opie-2-like retrotransposon family that are particularly abundant in this region of the genome.

  5. The Challenges and Opportunities Associated with Biofortification of Pearl Millet (Pennisetum glaucum) with Elevated Levels of Grain Iron and Zinc

    PubMed Central

    Manwaring, Hanna R.; Bligh, H. F. J.; Yadav, Rattan

    2016-01-01

    Deficiencies of essential micronutrients such as iron and zinc are the cause of extensive health problems in developing countries. They adversely affect performance, productivity and are a major hindrance to economic development. Since many people who suffer from micronutrient deficiencies are dependent on staple crops to meet their dietary requirements, the development of crop cultivars with increased levels of micronutrients in their edible parts is becoming increasingly recognized as a sustainable solution. This is largely facilitated by genetics and genomic platforms. The cereal crop pearl millet (Pennisetum glaucum), is an excellent candidate for genetic improvement due to its ability to thrive in dry, semi-arid regions, where farming conditions are often unfavorable. Not only does pearl millet grow in areas where other crops such as maize and wheat do not survive, it contains naturally high levels of micronutrients, proteins and a myriad of other health benefitting characteristics. This review discusses the current status of iron and zinc deficiencies and reasons why interventions such as fortification, supplementation, and soil management are neither practicable nor affordable in poverty stricken areas. We argue that the most cost effective, sustainable intervention strategy is to biofortify pearl millet with enhanced levels of bioavailable iron and zinc. We discuss how naturally occurring genetic variations present in germplasm collections can be incorporated into elite, micronutrient rich varieties and what platforms are available to drive this research. We also consider the logistics of transgenic methods that could facilitate the improvement of the pearl millet gene pool. PMID:28066495

  6. Genetic Diversity of Namibian Pennisetum glaucum (L.) R. BR. (Pearl Millet) Landraces Analyzed by SSR and Morphological Markers

    PubMed Central

    McBenedict, Billy; Chimwamurombe, Percy; Kwembeya, Ezekeil; Maggs-Kölling, Gillian

    2016-01-01

    Current Pennisetum glaucum (L.) R. BR. cultivars in Namibia have overall poor performance posing a threat to the nation's food security because this crop is staple for over 70% of the Namibian population. The crop suffers from undesirable production traits such as susceptibility to diseases, low yield, and prolonged reproductive cycle. This study aimed to understand the genetic diversity of the crop in Namibia by simple sequence repeats (SSRs) and morphology analysis. A total of 1441 genotypes were collected from the National Gene Bank representing all the Namibian landraces. A sample of 96 genotypes was further analyzed by SSR using Shannon-Wiener diversity index and revealed a value of 0.45 indicating low genetic diversity. Ordination using Principal Coordinate Analysis (PCoA) on SSR data confirmed clusters generated by UPGMA for the 96 P. glaucum accessions. UPGMA phenograms of 29 morphological characterized genotypes were generated for SSR and morphology data and the two trees revealed 78% resemblance. Lodging susceptibility, tillering attitude, spike density, fodder yield potential, early vigour, and spike shape were the phenotypic characters upon which some clusters were based in both datasets. It is recommended that efforts should be made to widen the current gene pool in Namibia. PMID:27433479

  7. Grass vs. legume forages for dairy cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa is the primary forage fed to lactating dairy cows; however, there is renewed interest in utilizing grass forages in lactating dairy cow diets particularly because of farm nutrient management issues. Yield and perceived quality is generally lower for grass species compared to legumes while ot...

  8. A Walk in the "Tall, Tall Grass"

    ERIC Educational Resources Information Center

    Kaatz, Kathryn

    2008-01-01

    This inquiry-based lesson was inspired by Denise Fleming's book entitled, "In the Tall, Tall Grass" (1991). The author used the book and a real study of prairie grasses to teach kindergartners how to make careful observations and record what they see. In addition, they learn how to "draw as scientists." Here the author describes her class's yearly…

  9. Fescues ‘leaf’ other grasses behind

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The yield and nutritive value of leaves, stems, and total forage of eight different perennial cool-season grasses were compared at 30-day intervals in spring, summer, and fall at two Wisconsin locations. Total forage production of all grasses was greatest during spring, as expected, and differences ...

  10. Change in growth performance of crossbred (Ankole × Jersey) dairy heifers fed on forage grass diets supplemented with commercial concentrates.

    PubMed

    Mutimura, Mupenzi; Ebong, Cyprian; Rao, Idupulapati Madhusudana; Nsahlai, Ignatius Verla

    2016-04-01

    Rearing heifers for dairy cow replacement is a challenge in smallholder dairy farms in the tropics due to feed shortage. The objective of this study was to evaluate Brachiaria hybrid cultivar Mulato II as a forage resource for improving growth performance of dairy heifers under cut-and-carry feeding system in Rwanda. Sixteen crossbred (Ankole × Jersey) heifers (mean weight 203 ± 35 kg) were randomly allocated to two dietary treatments viz: Mulato II with 2 kg/day of commercial concentrates (MCC) and Napier grass (Pennisetum purpureum) with the same supplement (NCC), for a period of 12 weeks. Mineral lick and water were provided ad libitum. Daily feed intake and fortnightly live weight were measured. Average daily gains and feed conversion ratio (FCR) were calculated. Results showed that absolute daily dry matter intake (g DMI/day) and relative intake (g/kg of metabolic body weight--BW(0.75)) were higher in heifers fed on MCC than in heifers fed on NCC (P < 0.001). FCR was lower (P < 0.001) in MCC than NCC diets. Final body weight (FBW) and body weight gain (BWG) did not differ between the two groups of heifers (P > 0.05). Average daily weight gain (ADWG) also not differed significantly (P > 0.05). Based on numerical body weight changes and nutritive values, Mulato II showed potential to be integrated into local cut-and-carry feeding systems for better heifer rearing to facilitate dairy cow replacement.

  11. Isolation and Screening of Rhizosphere Bacteria from Grasses in East Kavango Region of Namibia for Plant Growth Promoting Characteristics.

    PubMed

    Haiyambo, D H; Chimwamurombe, P M; Reinhold-Hurek, B

    2015-11-01

    A diverse group of soil bacteria known as plant growth promoting rhizobacteria (PGPR) is able to inhabit the area close to plant roots and exert beneficial effects on plant growth. Beneficial interactions between rhizospheric bacteria and plants provide prospects for isolating culturable PGPR that can be used as bio-fertilizers for sustainable crop production in communities that cannot easily afford chemical fertilizers. This study was conducted with the aim of isolating rhizospheric bacteria from grasses along the Kavango River and screening the bacterial isolates for plant growth promoting characteristics. The bacteria were isolated from rhizospheres of Phragmites australis, Sporobolus sp., Vetiveria nigritana, Pennisetum glaucum and Sorghum bicolor. The isolates were screened for inorganic phosphate solubilization, siderophore production and indole-3-acetic acid (IAA) production. The nitrogen-fixing capability of the bacteria was determined by screening for the presence of the nifH gene. Up to 21 isolates were obtained from P. australis, Sporobolus sp., S. bicolor, P. glaucum and V. nigritana. The genera Bacillus, Enterobacter, Kocuria, Pseudomonas and Stenotrophomonas, identified via 16S rDNA were represented in the 13 PGPR strains isolated. The isolates exhibited more than one plant growth promoting trait and they were profiled as follows: three phosphate solubilizers, four siderophore producers, eight IAA producing isolates and five nitrogen-fixers. These bacteria can be used to develop bio-fertilizer inoculants for improved soil fertility management and sustainable production of local cereals.

  12. Simulating long-term effectiveness and efficiency of management scenarios for an invasive grass

    USGS Publications Warehouse

    Jarnevich, Catherine S.; Holcombe, Tracy R.; Cullinane Thomas, Catherine; Frid, Leonardo; Olsson, Aaryn D.

    2015-01-01

    Resource managers are often faced with trade-offs in allocating limited resources to manage plant invasions. These decisions must often be made with uncertainty about the location of infestations, their rate of spread and effectiveness of management actions. Landscape level simulation tools such as state-and-transition simulation models (STSMs) can be used to evaluate the potential long term consequences of alternative management strategies and help identify those strategies that make efficient use of resources. We analyzed alternative management scenarios for African buffelgrass (Pennisetum ciliare syn. Cenchrus ciliaris) at Ironwood Forest National Monument, Arizona using a spatially explicit STSM implemented in the Tool for Exploratory Landscape Scenario Analyses (TELSA). Buffelgrass is an invasive grass that is spreading rapidly in the Sonoran Desert, affecting multiple habitats and jurisdictions. This invasion is creating a novel fire risk and transforming natural ecosystems. The model used in this application incorporates buffelgrass dispersal and establishment and management actions and effectiveness including inventory, treatment and post-treatment maintenance. We simulated 11 alternative scenarios developed in consultation with buffelgrass managers and other stakeholders. The scenarios vary according to the total budget allocated for management and the allocation of that budget between different kinds of management actions. Scenario results suggest that to achieve an actual reduction and stabilization of buffelgrass populations, management unconstrained by fiscal restrictions and across all jurisdictions and private lands is required; without broad and aggressive management, buffelgrass populations are expected to increase over time. However, results also suggest that large upfront investments can achieve control results that require relatively minimal spending in the future. Investing the necessary funds upfront to control the invasion results in the most

  13. Basalt Weathering, Nutrient Uptake, And Carbon Release By An Exotic And A Native Arizona Grass Species Under Different Temperature Conditions

    NASA Astrophysics Data System (ADS)

    Gallas, G.; Dontsova, K.; Chorover, J.; Hunt, E.; Ravi, S.

    2010-12-01

    During this past summer, the National Science Foundation funded a 10-week Research Experience for Undergraduates (REU) program “Environmental and Earth Systems Research at Biosphere 2”. This program provides undergraduates with an opportunity to conduct guided research in environmental and Earth systems science and has resulted in this work. Biosphere 2 allows for the exploration of complex questions in Earth sciences because of its large scale and the precise control allowed over many experimental elements. The goal of this study was to observe plant-mediated weathering of granular basalt under two temperature conditions. Two grass species were studied, one native to Arizona: Tanglehead, Heteropogan contortus, and one exotic to Arizona: Buffelgrass, Pennisetum ciliar. The grasses were grown in pots located in the Desert and the Savannah Biomes in the Biosphere 2 to take advantage of a 4° C temperature difference. Understanding differences in how native and invasive grasses weather soil and take up nutrients may explain the mechanism behind current invasion of Sonoran Desert by exotic species and help predict response of native and invasive vegetation to expected increase in temperatures. Each biome also contained three replicate “control” pots without vegetation, and mixtures of the two grass species to observe possible competition between the species. Three factors were compared in this study: 1. Temperature: the same species of grass under two different temperature conditions 2. Species: Native Arizonan species vs. a species exotic to Arizona 3. Temporal: How the grasses use resources differently as they grow Leachate samples were collected and analyzed for pH, electrical conductivity, total organic carbon, total nitrogen, inorganic carbon by high temperature combustion coupled with infrared gas analysis; F-, Cl-, Br-, NO3-, NO2-, SO42-, and PO43- by ion chromatography; and cations and metals by ICP-MS. The data trends indicate that plants enhanced

  14. Evolution of Grasses and Grassland Ecosystems

    NASA Astrophysics Data System (ADS)

    Strömberg, Caroline A. E.

    2011-05-01

    The evolution and subsequent ecological expansion of grasses (Poaceae) since the Late Cretaceous have resulted in the establishment of one of Earth's dominant biomes, the temperate and tropical grasslands, at the expense of forests. In the past decades, several new approaches have been applied to the fossil record of grasses to elucidate the patterns and processes of this ecosystem transformation. The data indicate that the development of grassland ecosystems on most continents was a multistage process involving the Paleogene appearance of (C3 and C4) open-habitat grasses, the mid-late Cenozoic spread of C3 grass-dominated habitats, and, finally, the Late Neogene expansion of C4 grasses at tropical-subtropical latitudes. The evolution of herbivores adapted to grasslands did not necessarily coincide with the spread of open-habitat grasses. In addition, the timing of these evolutionary and ecological events varied between regions. Consequently, region-by-region investigations using both direct (plant fossils) and indirect (e.g., stable carbon isotopes, faunas) evidence are required for a full understanding of the tempo and mode of grass and grassland evolution.

  15. Structure, agency, and the transformation of the Sonoran Desert by buffelgrass (Pennisetum ciliare): An application of land change science

    NASA Astrophysics Data System (ADS)

    Brenner, Jacob C.

    A regional land transformation is underway in the Sonoran Desert of southwestern North America as a result of the conversion of native rangeland to exotic pasture. In northwestern Sonora, Mexico the process involves clearing native vegetation for cultivation of buffelgrass (Pennisetum ciliare). Southern African buffelgrass was introduced to Sonora through the United States in the 1950s with generous support from the Mexican federal and Sonoran state governments. The ascendance of buffelgrass as a range management tool in Sonora has been conditioned by an international political economy of beef production. However, land use decisions regarding buffelgrass are also conditioned by factors internal to the ranch household. This research examines the expansion of buffelgrass in the Sonoran Desert, addressing its extent and drivers. Through the use of systematic interviews with ranchers, key informant interviews with government officials, and an examination of northern Mexico's cattle ranching history and policy, the dissertation documents why buffelgrass has spread as a policy program and management choice. This part of the work addresses a "structure-agency debate" in human-environment geography. Next the research turns to landscape impacts of buffelgrass cultivation, through vegetation plot and transect sampling. The extent, cover, and density of buffelgrass inside and outside fenced pastures are examined, confirming the hypothesis that disturbance facilitates invasion from pastures onto surrounding lands. Finally, the research employs novel methods of remote sensing and geographic information science using a 1973-2006 time series of Landsat imagery to characterize the patterns and temporal trajectories of land change by buffelgrass across the site. Object-based image processing techniques are combined with traditional maximum likelihood techniques and classification tree analysis to address the difficult task of distinguishing buffelgrass from other prevalent land

  16. The synergistic effect of drought and light stresses in sorghum and pearl millet. [Pennisetum glaucum; Sorghum bicolor

    SciTech Connect

    Masojidek, M.; Trivedi, S.; Halshaw, L.; Alexiou, A.; Hall, D.O. )

    1991-05-01

    The effect of drought stress and high irradiance and their combination were studied under laboratory conditions using young plants of a very drought-resistant variety, ICMH 451, of pearl millet (Pennisetum glaucum) and three varieties of sorghum (Sorghum bicolor) - one drought-resistant from India, one drought-tolerant from Texas, and one drought-sensitive variety from France. CO{sub 2} assimilation rates and photosystem II fluorescence in leaves were analyzed in parallel with photosynthetic electron transport, photosystem II fluorescence, and chlorophyll-protein composition in chloroplasts isolated from these leaves. High irradiance slightly increased CO{sub 2} assimilation rates and electron transport activities of irrigated plants but not fluorescence. Drought stress (less than {minus}1 megapascal) depressed CO{sub 2} assimilation rates, fluorescence, and electron transport. Under the combined effect of drought stress and high irradiance, CO{sub 2} assimilation rates, fluorescence, and electron transport. Under the combined effects of drought stress and high irradiance, CO{sub 2} assimilation rates and fluorescence were severely inhibited in leaves, as were the photosynthetic electron transport. Under the combined effects of drought stress and high irradiance, CO{sub 2} assimilation rates and fluorescence were severely inhibited in leaves, as were the photosynthetic electron transport activities and fluorescence in chloroplasts (but not photosystem I activity). The synergistic or distinctive effect of drought and high irradiance is discussed. The experiments with pearl millet and three varieties of sorghum showed that different responses of plants to drought and light stresses can be monitored by plant physiological and biochemical techniques. Some of these techniques may have a potential for selection of stress-resistant varieties using seedlings.

  17. Transcriptome analysis of differentially expressed genes during embryo sac development in apomeiotic non-parthenogenetic interspecific hybrid of Pennisetum glaucum.

    PubMed

    Sahu, Pranav Pankaj; Gupta, Sarika; Malaviya, D R; Roy, Ajoy Kumar; Kaushal, Pankaj; Prasad, Manoj

    2012-07-01

    Apomixis results in the production of genetically uniform progeny, derived from the fertilization independent development (parthenogenesis) of an unreduced egg cell (apomeiosis). To identify genes involved in the apomeiosis, a comparative transcriptome analysis of differentially expressed genes during embryo sac (ES) development in a sexual Pennisetum glaucum (genotype 81A1) and its apomeiotic (aposporic) non-parthenogenetic interspecific hybrid (BC1GO) was investigated. BC1GO exhibited the partitioned apomeiosis component, whereby the second apomixis component viz., parthenogenesis was completely lacking. A total of 96 non-redundant transcripts were recovered using suppression subtractive hybridization and classified into 11 different categories according to their putative functions. Amongst the identified transcripts, many of them belonged to unknown function (40%) followed by those involved in protein metabolism, stress response, pollen/ovule/embryo development, and translation/protein modification process. A data search of transcriptional profiling in other apomictic species revealed that 75% of the differentially expressed transcripts have not been reported in previous studies. By macroarray analysis, we identified differential expression pattern of 96 transcripts, 45 (47%) of which showed ≥2-fold induction in apomeiotic BC1GO. Further, the obtained results were validated by quantitative real-time polymerase chain reaction to have a comparative expression profiling of eight selected up-regulated transcripts (≥2.5-fold) between BC1GO and 81A1 at different phases of ovule development. In silico mapping demonstrated that 13 transcripts were located onto rice chromosome 2, region syntenic with the apospory locus as reported in Brachiaria brizantha and Paspalum notatum. The expression patterns of these transcripts showed a significant difference at differentiating megaspore mother cell and gametogenesis stages thereby suggesting their involvement in floral

  18. Genome sequence analysis of the model grass Brachypodium distachyon: insights into grass genome evolution

    SciTech Connect

    Schulman, Al

    2009-08-09

    Three subfamilies of grasses, the Erhardtoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the complete genome sequence of the wild grass Brachypodium distachyon (Brachypodium), the first member of the Pooideae subfamily to be completely sequenced. Comparison of the Brachypodium, rice and sorghum genomes reveals a precise sequence- based history of genome evolution across a broad diversity of the grass family and identifies nested insertions of whole chromosomes into centromeric regions as a predominant mechanism driving chromosome evolution in the grasses. The relatively compact genome of Brachypodium is maintained by a balance of retroelement replication and loss. The complete genome sequence of Brachypodium, coupled to its exceptional promise as a model system for grass research, will support the development of new energy and food crops

  19. New Developments in Grasses for Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New forage varieties with improved traits are an essential component of best management practices for livestock agriculture. This paper discusses new varieties of several cool-season forage grasses used for pasture production....

  20. Watching Grass Grow: Biology Explorations Online.

    ERIC Educational Resources Information Center

    Puttick, Gillian

    2002-01-01

    Describes an online biology course for science teachers in a master's degree program that focuses on the adaptation and natural selection of grass under environmental challenges. Provides experience with how biologists use questioning and investigation in their research. (YDS)

  1. Underwater Grass Comeback Helps Chesapeake Bay

    EPA Pesticide Factsheets

    The fortified Susquehanna Flats, the largest bed of underwater grasses in the Chesapeake Bay, seems able to withstand a major weather punch. Its resilience is contributing to an overall increase in the Bay’s submerged aquatic vegetation.

  2. Exogenous calcium induces tolerance to atrazine stress in Pennisetum seedlings and promotes photosynthetic activity, antioxidant enzymes and psbA gene transcripts.

    PubMed

    Erinle, Kehinde Olajide; Jiang, Zhao; Ma, Bingbing; Li, Jinmei; Chen, Yukun; Ur-Rehman, Khalil; Shahla, Andleeb; Zhang, Ying

    2016-10-01

    Calcium (Ca) has been reported to lessen oxidative damages in plants by upregulating the activities of antioxidant enzymes. However, atrazine mediated reactive oxygen species (ROS) reduction by Ca is limited. This study therefore investigated the effect of exogenously applied Ca on ROS, antioxidants activity and gene transcripts, the D1 protein (psbA gene), and chlorophyll contents in Pennisetum seedlings pre-treated with atrazine. Atrazine toxicity increased ROS production and enzyme activities (ascorbate peroxidase APX, peroxidase POD, Superoxide dismutase SOD, glutathione-S-transferase GST); but decreased antioxidants (APX, POD, and Cu/Zn SOD) and psbA gene transcripts. Atrazine also decreased the chlorophyll contents, but increased chlorophyll (a/b) ratio. Contrarily, Ca application to atrazine pre-treated seedlings lowered the harmful effects of atrazine by reducing ROS levels, but enhancing the accumulation of total chlorophyll contents. Ca-protected seedlings in the presence of atrazine manifested reduced APX and POD activity, whereas SOD and GST activity was further increased with Ca application. Antioxidant gene transcripts that were down-regulated by atrazine toxicity were up-regulated with the application of Ca. Calcium application also resulted in up-regulation of the D1 protein. In conclusion, ability of calcium to reverse atrazine-induced oxidative damage and calcium regulatory role on GST in Pennisetum was presented.

  3. Post senescent grass canopy remote sensing

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.

    1978-01-01

    Analysis of in situ collected spectral reflectance data from a dormant or senescent grass canopy showed a direct relationship existed between spectral reflectance and biomass for the 0.50-0.80 micron spectral region. The data, collected four weeks after the end of the growing season, indicated that post senescent remote sensing of grass canopy biomass is possible and helps to elucidate the spectral contribution of recently dead vegetation in mixed live/dead canopy situations.

  4. Molecular control of grass inflorescence development.

    PubMed

    Zhang, Dabing; Yuan, Zheng

    2014-01-01

    The grass family is one of the largest families in angiosperms and has evolved a characteristic inflorescence morphology, with complex branches and specialized spikelets. The origin and development of the highly divergent inflorescence architecture in grasses have recently received much attention. Increasing evidence has revealed that numerous factors, such as transcription factors and plant hormones, play key roles in determining reproductive meristem fate and inflorescence patterning in grasses. Moreover, some molecular switches that have been implicated in specifying inflorescence shapes contribute significantly to grain yields in cereals. Here, we review key genetic and molecular switches recently identified from two model grass species, rice (Oryza sativa) and maize (Zea mays), that regulate inflorescence morphology specification, including meristem identity, meristem size and maintenance, initiation and outgrowth of axillary meristems, and organogenesis. Furthermore, we summarize emerging networks of genes and pathways in grass inflorescence morphogenesis and emphasize their evolutionary divergence in comparison with the model eudicot Arabidopsis thaliana. We also discuss the agricultural application of genes controlling grass inflorescence development.

  5. Madagascar's grasses and grasslands: anthropogenic or natural?

    PubMed

    Vorontsova, Maria S; Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W Derek; Ficinski, Paweł; Savva, George M; Nanjarisoa, Olinirina P; Razanatsoa, Jacqueline; Randriatsara, Fetra O; Kimeu, John M; Luke, W R Quentin; Kayombo, Canisius; Linder, H Peter

    2016-01-27

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics.

  6. Madagascar's grasses and grasslands: anthropogenic or natural?

    PubMed Central

    Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W. Derek; Ficinski, Paweł; Savva, George M.; Nanjarisoa, Olinirina P.; Razanatsoa, Jacqueline; Randriatsara, Fetra O.; Kimeu, John M.; Luke, W. R. Quentin; Kayombo, Canisius; Linder, H. Peter

    2016-01-01

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. PMID:26791612

  7. Inoculation with endophytic Bacillus megaterium 1Y31 increases Mn accumulation and induces the growth and energy metabolism-related differentially-expressed proteome in Mn hyperaccumulator hybrid pennisetum.

    PubMed

    Zhang, Wen-hui; He, Lin-yan; Wang, Qi; Sheng, Xia-Fang

    2015-12-30

    In this study, a hydroponic culture experiment was conducted in a greenhouse to investigate the molecular and microbial mechanisms involved in the endophytic Bacillus megaterium 1Y31-enhanced Mn tolerance and accumulation in Mn hyperaccumulator hybrid pennisetum. Strain 1Y31 significantly increased the dry weights (ranging from 28% to 94%) and total Mn uptake (ranging from 23% to 112%) of hybrid pennisetum treated with 0, 2, and 10mM Mn compared to the control. Total 98 leaf differentially expressed proteins were identified between the live and dead bacterial inoculated hybrid pennisetum. The major leaf differentially expressed proteins were involved in energy generation, photosynthesis, response to stimulus, metabolisms, and unknown function. Furthermore, most of the energy generation and photosynthesis-related proteins were up-regulated, whereas most of the response to stimulus and metabolism-related proteins were down-regulated under Mn stress. Notably, the proportion of indole-3-acetic acid (IAA)-producing endophytic bacteria was significantly higher in the bacterial inoculated plants under Mn stress. The results suggested that strain 1Y31 increased the growth and Mn uptake of hybrid pennisetum through increasing the efficiency of photosynthesis and energy metabolism as well as the proportion of plant growth-promoting endophytic bacteria in the plants.

  8. Rye grass is associated with fewer non-contact anterior cruciate ligament injuries than bermuda grass

    PubMed Central

    Orchard, J; Chivers, I; Aldous, D; Bennell, K; Seward, H

    2005-01-01

    Objective: To assess the contribution of ground variables including grass type to the rate of anterior cruciate ligament (ACL) injury in the Australian Football League (AFL), specifically which factors are primarily responsible for previously observed warm season and early season biases for ACL injuries. Methods: Grass types used at the major AFL venues from 1992 to 2004 were established by consultation with ground managers, and ground hardness and other weather variables were measured prospectively. Results: There were 115 ACL injuries occurring in matches during the survey time period, 88 with a non-contact mechanism. In multivariate analysis, use of bermuda (couch) grass as opposed to rye grass, higher grade of match, and earlier stage of the season were independent risk factors for non-contact ACL injury. Ground hardness readings did not show a significant association with ACL injury risk, whereas weather variables of high evaporation and low prior rainfall showed univariate association with injury risk but could not be entered into a logistic regression equation. Discussion: Rye grass appears to offer protection against ACL injury compared with bermuda (couch) grass fields. The likely mechanism is reduced "trapping" of football boots by less thatch. Grass species as a single consideration cannot fully explain the ACL early season bias, but is probably responsible for the warm season bias seen in the AFL. Weather variables previously identified as predictors are probably markers for predominance of bermuda over rye grass in mixed fields. PMID:16183765

  9. Gene Expression Profiling of Grass Carp (Ctenopharyngodon idellus) and Crisp Grass Carp

    PubMed Central

    Yu, Ermeng; Xie, Jun; Wang, Guangjun; Yu, Deguang; Gong, Wangbao; Li, Zhifei; Wang, Haiying; Xia, Yun; Wei, Nan

    2014-01-01

    Grass carp (Ctenopharyngodon idellus) is one of the most important freshwater fish that is native to China, and crisp grass carp is a kind of high value-added fishes which have higher muscle firmness. To investigate biological functions and possible signal transduction pathways that address muscle firmness increase of crisp grass carp, microarray analysis of 14,900 transcripts was performed. Compared with grass carp, 127 genes were upregulated and 114 genes were downregulated in crisp grass carp. Gene ontology (GO) analysis revealed 30 GOs of differentially expressed genes in crisp grass carp. And strong correlation with muscle firmness increase of crisp grass carp was found for these genes from differentiation of muscle fibers and deposition of ECM, and also glycolysis/gluconeogenesis pathway and calcium metabolism may contribute to muscle firmness increase. In addition, a number of genes with unknown functions may be related to muscle firmness, and these genes are still further explored. Overall, these results had been demonstrated to play important roles in clarifying the molecular mechanism of muscle firmness increase in crisp grass carp. PMID:25525591

  10. Determinants of flammability in savanna grass species.

    PubMed

    Simpson, Kimberley J; Ripley, Brad S; Christin, Pascal-Antoine; Belcher, Claire M; Lehmann, Caroline E R; Thomas, Gavin H; Osborne, Colin P

    2016-01-01

    Tropical grasses fuel the majority of fires on Earth. In fire-prone landscapes, enhanced flammability may be adaptive for grasses via the maintenance of an open canopy and an increase in spatiotemporal opportunities for recruitment and regeneration. In addition, by burning intensely but briefly, high flammability may protect resprouting buds from lethal temperatures. Despite these potential benefits of high flammability to fire-prone grasses, variation in flammability among grass species, and how trait differences underpin this variation, remains unknown.By burning leaves and plant parts, we experimentally determined how five plant traits (biomass quantity, biomass density, biomass moisture content, leaf surface-area-to-volume ratio and leaf effective heat of combustion) combined to determine the three components of flammability (ignitability, sustainability and combustibility) at the leaf and plant scales in 25 grass species of fire-prone South African grasslands at a time of peak fire occurrence. The influence of evolutionary history on flammability was assessed based on a phylogeny built here for the study species.Grass species differed significantly in all components of flammability. Accounting for evolutionary history helped to explain patterns in leaf-scale combustibility and sustainability. The five measured plant traits predicted components of flammability, particularly leaf ignitability and plant combustibility in which 70% and 58% of variation, respectively, could be explained by a combination of the traits. Total above-ground biomass was a key driver of combustibility and sustainability with high biomass species burning more intensely and for longer, and producing the highest predicted fire spread rates. Moisture content was the main influence on ignitability, where species with higher moisture contents took longer to ignite and once alight burnt at a slower rate. Biomass density, leaf surface-area-to-volume ratio and leaf effective heat of combustion

  11. Thunderstorm asthma due to grass pollen.

    PubMed

    Suphioglu, C

    1998-08-01

    It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. Moreover, grass pollen is also responsible for triggering allergic asthma, gaining impetus as a result of the 1987/1989 Melbourne and 1994 London thunderstorm-associated asthma epidemics. However, grass pollen is too large to gain access into the lower airways to trigger the asthmatic response and micronic particles <5 micro m are required to trigger the response. We have successfully shown that ryegrass pollen ruptures upon contact with water, releasing about 700 starch granules which not only contain the major allergen Lol p 5, but have been shown to trigger both in vitro and in vivo IgE-mediated responses. Furthermore, starch granules have been isolated from the Melbourne atmosphere with 50-fold increase following rainfall. Free grass pollen allergen molecules have been recently shown to interact with other particles including diesel exhaust carbon particles, providing a further transport mechanism for allergens to gain access into lower airways. In this review, implication and evidence for grass pollen as a trigger of thunderstorm-associated asthma is presented. Such information is critical and mandatory for patient education and training in their allergen avoidance programs. More importantly, patients with serum IgE to group 5 allergens are at high risk of allergic asthma, especially those not protected by medication. Therefore, a system to determine the total atmospheric allergen load and devising of an effective asthma risk forecast is urgently needed and is subject to current investigation.

  12. Molecular aspects of flower development in grasses.

    PubMed

    Ciaffi, Mario; Paolacci, Anna Rita; Tanzarella, Oronzo Antonio; Porceddu, Enrico

    2011-12-01

    The grass family (Poaceae) of the monocotyledons includes about 10,000 species and represents one of the most important taxa among angiosperms. Their flower morphology is remarkably different from those of other monocotyledons and higher eudicots. The peculiar floral structure of grasses is the floret, which contains carpels and stamens, like eudicots, but lacks petals and sepals. The reproductive organs are surrounded by two lodicules, which correspond to eudicot petals, and by a palea and lemma, whose correspondence to eudicot organs remains controversial. The molecular and genetic analysis of floral morphogenesis and organ specification, primarily performed in eudicot model species, led to the ABCDE model of flower development. Several genes required for floral development in grasses correspond to class A, B, C, D, and E genes of eudicots, but others appear to have unique and diversified functions. In this paper, we outline the present knowledge on the evolution and diversification of grass genes encoding MIKC-type MADS-box transcription factors, based on information derived from studies in rice, maize, and wheat. Moreover, we review recent advances in studying the genes involved in the control of flower development and the extent of structural and functional conservation of these genes between grasses and eudicots.

  13. Evolution of Centromeric Retrotransposons in Grasses

    PubMed Central

    Sharma, Anupma; Presting, Gernot G.

    2014-01-01

    Centromeric retrotransposons (CRs) constitute a family of plant retroelements, some of which have the ability to target their insertion almost exclusively to the functional centromeres. Our exhaustive analysis of CR family members in four grass genomes revealed not only horizontal transfer (HT) of CR elements between the oryzoid and panicoid grass lineages but also their subsequent recombination with endogenous elements that in some cases created prolific recombinants in foxtail millet and sorghum. HT events are easily identifiable only in cases where host genome divergence significantly predates HT, thus documented HT events likely represent only a fraction of the total. If the more difficult to detect ancient HT events occurred at frequencies similar to those observable in present day grasses, the extant long terminal repeat retrotransposons represent the mosaic products of HT and recombination that are optimized for retrotransposition in their host genomes. This complicates not only phylogenetic analysis but also the establishment of a meaningful retrotransposon nomenclature, which we have nevertheless attempted to implement here. In contrast to the plant-centric naming convention used currently for CR elements, we classify elements primarily based on their phylogenetic relationships regardless of host plant, using the exhaustively studied maize elements assigned to six different subfamilies as a standard. The CR2 subfamily is the most widely distributed of the six CR subfamilies discovered in grass genomes to date and thus the most likely to play a functional role at grass centromeres. PMID:24814286

  14. Southern Florida's River of Grass

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Florida's Everglades is a region of broad, slow-moving sheets of water flowing southward over low-lying areas from Lake Okeechobeeto the Gulf of Mexico. In places this remarkable 'river of grass' is 80 kilometers wide. These images from the Multi-angle Imaging SpectroRadiometer show the Everglades region on January 16, 2002. Each image covers an area measuring 191 kilometers x 205 kilometers. The data were captured during Terra orbit 11072.

    On the left is a natural color view acquired by MISR's nadir camera. A portion of Lake Okeechobee is visible at the top, to the right of image center. South of the lake, whose name derives from the Seminole word for 'big water,' an extensive region of farmland known as the Everglades Agricultural Area is recognizable by its many clustered squares. Over half of the sugar produced in United States is grown here. Urban areas along the east coast and in the northern part of the image extend to the boundaries of Big Cypress Swamp, situated north of Everglades National Park.

    The image on the right combines red-band data from the 46-degree backward, nadir and 46-degree forward-viewing camera angles to create a red, green, blue false-color composite. One of the interesting uses of the composite image is for detecting surface water. Wet surfaces appear blue in this rendition because sun glitter produces a greater signal at the forward camera's view angle. Wetlands visible in these images include a series of shallow impoundments called Water Conservation Areas which were built to speed water flow through the Everglades in times of drought. In parts of the Everglades, these levees and extensive systems such as the Miami and Tamiami Canals have altered the natural cycles of water flow. For example, the water volume of the Shark River Slough, a natural wetland which feeds Everglades National Park, is influenced by the Tamiami Canal. The unique and intrinsic value of the Everglades is now widely recognized, and efforts to restore

  15. Grass pollen immunotherapy: where are we now.

    PubMed

    Würtzen, Peter A; Gupta, Shashank; Brand, Stephanie; Andersen, Peter S

    2016-01-01

    During allergen immunotherapy (AIT), the allergic patient is exposed to the disease-inducing antigens (allergens) in order to induce clinical and immunological tolerance and obtain disease modification. Large trials of grass AIT with highly standardized subcutaneous and sublingual tablet vaccines have been conducted to document the clinical effect. Induction of blocking antibodies as well as changes in the balance between T-cell phenotypes, including induction of regulatory T-cell subtypes, have been demonstrated for both treatment types. These observations increase the understanding of the immunological mechanism behind the clinical effect and may make it possible to use the immunological changes as biomarkers of clinical effect. The current review describes the recent mechanistic findings for subcutaneous immunotherapy and sublingual immunotherapy/tablet treatment and discusses how the observed immunological changes translate into a scientific foundation for the observed clinical effects of grass pollen immunotherapy and lead to new treatment strategies for grass AIT.

  16. Molecular biomarkers for grass pollen immunotherapy

    PubMed Central

    Popescu, Florin-Dan

    2014-01-01

    Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines. PMID:25237628

  17. Guidelines for growing perennial grasses for biofuel and bioproducts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Guidelines for growing perennial grasses for biofuel and bioproducts Rob Mitchell Abstract: Switchgrass, big bluestem, and warm-season grass mixtures provide numerous benefits. Existing field equipment, herbicides, and cultivar improvement promote rapid establishment in the planting year. These gra...

  18. Meiotic and reproductive behavior of facultative apomictic BC/sub 1/ offspring derived from Pennisetum americanum-P. orientale interspecific hybrids

    SciTech Connect

    Dujardin, M.; Hanna, W.W.

    1983-01-01

    This study reports on the chromosome numbers, meiotic behavior, method of reproduction and fertility of BC/sub 1/ progenies from Pennisetum americanum L. Leeke, pearl millet X P. orientale L.C. Rich. interspecific hybrids backcrossed to P. americanum. This information would be useful for future studies on transfer of genes controlling apomixis from the tertiary gene pool to P. americanum. Two facultatively apomictic interspecific hybrids between Pennisetum americanum, (A. chromosomes) and P. orientale (O chromosomes), 2n=25, were pollinated with P. americanum. Sixteen backcross progenies were obtained which were of three cytotypes: 32-(14 A + 18 O), 23-(14 A + 9 O), and 27-(7 A + 20 O) chromosomes. They resulted from fertilization of unreduced gametes or partially reduced gametes by a 7 A chromosome gamete, or by development or unreduced aposporic embryo sacs, respectively. In 23 chromosome plants, the 14 A chromosomes paired mainly as bivalents or remained as univalents while the 9 O chromosomes appeared as univalents. Intergenomal pairing between P. americanum and P. orientale also were observed and could make segmental exchange possible. In the 27 chromosome progeny, the 20 O chromosomes paired, while the 7 A chromosomes remained as univalents. Meiotic behavior in 32-chromosome plants was regular with 7 A bivalents plus 9 O bivalents. The backcross progenies were male sterile but partially female fertile and produced a few seeds when pollinated with P. americanum pollen. The 23-chromosome, BC/sub 1/ progeny were reconstituted in BC/sub 2/ progenies of 32-chromosomes plants X pearl millet. All BC/sub 1/ had some degree of apomicitic embryo sac development and the 23-chromosome plants showed apomictic development even though the O chromosomes were in the simplex condition.

  19. Cultivation of the culinary-medicinal Lung Oyster mushroom, Pleurotus pulmonarius (Fr.) Quél. (Agaricomycetideae) on grass plants in Taiwan.

    PubMed

    Liang, Zeng-Chin; Wu, Kuan-Jzen; Wang, Jinn-Chyi; Lin, Chorng-Horng; Wu, Chiu-Yeh

    2011-01-01

    Cultivation of the culinary-medicinal Lung Oyster mushroom, Pleurotus pulmonarius, on the stalks of three grass plants, i.e., Panicum repens, Pennisetum purpureum, and Zea mays were investigated. The effects of various combinatorial substrates on mushroom mycelial growth and yield calculated as biological efficiency (BE) were determined. Among 9 experimental substrates, the most suitable substrate for mycelial growth was 45ZMS:45S, followed by 45PRS:45S; their mycelial growth rates were obviously quicker than that of the control substrate. The BEs of all the experimental substrates respectively containing P. repens stalk, P. purpureum stalk and Z. mays stalk were higher than that of the control (39.55%) during the 2.5 months of cultivation period. The best substrate in terms of BE was 60ZMS:30S (58.33%), followed by 45PRS:45S (57.16%), 45ZMS:45S (49.86%), and 30ZMS:60S (47.20%). Based on the BE of the tested substrates, Z mays stalk appeared to be the best alternative material for the production of P. pulmonarius.

  20. Isotopic signatures of vegetation change on northern mixed grass prairie

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National analyses have shown invasion of northern mixed-grass prairie by nonnative grasses such as Kentucky bluegrass (Poa pratensis L.). Invasion of native prairie by nonnative grasses may compromise ecosystem function and limit potential ecosystem services. Recent data from a long-term (100 year) ...

  1. Native Grasses as a Management Alternative on Vegetated Closure Caps

    NASA Astrophysics Data System (ADS)

    Kwit, Charles; Collins, Beverly

    2008-06-01

    Capped waste sites often are vegetated with commercial turf grasses to increase evapotranspiration and prevent erosion and possible exposure of the barrier. Fertilizer, frequent watering, and mowing may be required to establish the turf grass and prevent invasion by trees and shrubs. Oldfield vegetation of grasses and forbs is a possible sustainable alternative to turf grass communities. To determine if oldfield vegetation can establish on caps, we (1) compared establishment of a dominant oldfield grass and a commercial turf grass under different combinations of new closure cap management: spring or summer planting and presence or absence of amendments to alleviate drought (watering, mulch) or increase soil fertility (fertilizer, lime, a nitrogen-fixing legume); (2) surveyed existing caps to determine if oldfield species establish naturally; and (3) performed a greenhouse experiment to compare growth of two native grasses under low and amended (added water, soil nutrients) conditions. Both the commercial grass and oldfield species established under new cap conditions; fertilizer, water, and mulch improved vegetation establishment in spring or summer, but legumes decreased grass cover. In the greenhouse, both native grasses grew best with amendments; however, substantial stem and root length were obtained with no fertilizer and only once-weekly watering. Existing vegetated caps supported planted grasses and naturally established oldfield species. Overall, the results indicate native grasses can establish on new caps and oldfields can serve as a management model; further work is needed to determine the management strategy to maintain herbaceous vegetation and slow woody species invasion.

  2. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss... boundaries; and (3) Be managed and maintained using acceptable growing practices for the geographical...

  3. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss... boundaries; and (3) Be managed and maintained using acceptable growing practices for the geographical...

  4. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss... boundaries; and (3) Be managed and maintained using acceptable growing practices for the geographical...

  5. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss..., as determined by CCC. (e) The land, waterbed, or facility in which the eligible commodity was...

  6. 7 CFR 1437.310 - Sea grass and sea oats.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Sea grass and sea oats. 1437.310 Section 1437.310... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value loss..., as determined by CCC. (e) The land, waterbed, or facility in which the eligible commodity was...

  7. A Tensile Strength of Bermuda Grass and Vetiver Grass in Terms of Root Reinforcement Ability Toward Soil Slope Stabilization

    NASA Astrophysics Data System (ADS)

    Noorasyikin, M. N.; Zainab, M.

    2016-07-01

    An examination on root characteristics and root properties has been implemented in this study. Two types of bioengineering were chose which are Vetiver grass and Bermuda grass as these grasses were widely applied for slope stabilization. The root samples were taken to the laboratory to investigate its classification, characteristics and strength. The root of both grasses was found grow with fibrous root matrix system. In terms of root anchorage, the root matrix system of Vetiver grass was exhibits more strengthen than the Bermuda grass. However, observation on root image from Scanning Electron Microscope test reveals that the root of Vetiver grass becomes non-porous as the moisture content reduced. Meanwhile, the root tensile strength of Bermuda grass was obtained acquired low value with higher percentage of moisture content, root morphology and bonding strength. The results indicated that the root tensile strength is mainly influence by percentage of moisture content and root morphology.

  8. Effect of palm kernel cake as protein source in a concentrate diet on intake, digestibility and live weight gain of goats fed Napier grass.

    PubMed

    Rahman, Mohammad Mijanur; Abdullah, Ramli Bin; Wan Embong, Wan Khadijah; Nakagawa, Toshinori; Akashi, Ryo

    2013-03-01

    The effects of palm kernel cake (PKC) as a protein source in a concentrate diet (comprising 35 % crushed maize, 30 % rice bran, 32 % PKC, 2 % vitamin mineral premix and 1 % salt) were examined on intake, live weight (LW) gain and digestibility in female goats (average LW of 12.4 ± 2.6 kg). Four goats were randomly allocated to each of the four treatment diets: (a) Napier grass (Pennisetum purpureum) offered ad libitum (T1), (b) T1 + concentrate at 0.5 % of LW (T2), (c) T1 + concentrate at 1.0 % of LW (T3) and (d) T1 + concentrate at 2.0 % of LW (T4). A 7-day digestibility trial and an 82-day growth experiment were conducted. No differences were observed among diets for intakes of roughage dry matter (DM), total DM, organic matter (OM) and neutral detergent fibre (NDF). The crude protein (CP) intake increased (P < 0.05) as the level of concentrate in the diets increased. Goats fed the T2, T3 and T4 diets gained 10.2, 34.1 and 52.5 g/head/day, respectively, while the control group (T1) lost weight (-12.7 g/head/day). The apparent digestibilities of DM, OM and CP were similar (P > 0.05) among treatments. The digestibility of dietary NDF decreased (P < 0.05) with increasing levels of concentrate, but there was no significant (P > 0.05) difference between T2 and T3 diets. Supplementing a basal diet of Napier grass with PKC-based concentrate improved CP intake and LW gain. The PKC-based concentrate diet can therefore be exploited for the use of local feed resources for goat production; however, further research is required to achieve the best growth response.

  9. Effects of feeding ground pods of Enterolobium cyclocarpum Jacq. Griseb on dry matter intake, rumen fermentation, and enteric methane production by Pelibuey sheep fed tropical grass.

    PubMed

    Albores-Moreno, S; Alayón-Gamboa, J A; Ayala-Burgos, A J; Solorio-Sánchez, F J; Aguilar-Pérez, C F; Olivera-Castillo, L; Ku-Vera, J C

    2017-04-01

    An experiment was carried out to determine the effect of supplementing ground pods of Enterolobium cyclocarpum in a basal ration of Pennisetum purpureum grass on feed intake, rumen volatile fatty acids (VFAs), and protozoa and methane (CH4) production by hair sheep. Four male sheep (Pelibuey × Katahdin) with a mean live weight of 27.0 kg (SD ± 0.5) were supplemented with 0.00, 0.15, 0.30, and 0.45 kg of dry matter (DM) of E. cyclocarpum pods daily; equivalent to 0.00, 4.35, 8.70, and 13.05 g of crude saponins, respectively. Dry matter intake (DMI), organic matter intake (OMI), and molar proportions of propionic acid increased linearly (P < 0.05) as pods of E. cyclocarpum in the ration were increased. Higher intakes of DM and OM were found when lambs were fed 0.45 kg DM per day of E. cyclocarpum, and the highest proportion of propionic acid (0.21 and 0.22, respectively) was obtained with 0.15 and 0.30 kg of DM per lamb of E. cyclocarpum, while apparent digestibility of neutral detergent fiber (NDF) and molar proportion of acetic acid were reduced (P < 0.05). Rumen CH4 production decreased (P < 0.05) when 0.30 and 0.45 kg of DM/lamb/day of E. cyclocarpum were fed (21.8 and 25.3 L CH4/lamb/day, respectively). These results suggest that to improve the feeding of sheep fed tropical grass, it is advisable to supplement the basal ration with up to 0.30 kg DM of E. cyclocarpum pods.

  10. Grassroots e-floras in the Poaceae: growing GrassBase and GrassWorld

    PubMed Central

    Vorontsova, Maria S.; Clayton, Derek; Simon, Bryan K.

    2015-01-01

    Abstract GrassBase and GrassWorld are the largest structured descriptive datasets in plants, publishing descriptions of 11,290 species in the DELTA format. Twenty nine years of data compilation and maintenance have created a dataset which now underpins much of the Poaceae bioinformatics. GrassBase and GrassWorld can continue to grow productively if the proliferation of alternative classifications and datasets can be brought together into a consensus system. If the datasets are reconciled instead of diverging further apart a long term cumulative process can bring knowledge together for great future utility. This paper presents the Poaceae as the first and largest model system for e-taxonomy and the study of classification development in plants. The origin, development, and content of both datasets is described and key contributors are noted. The challenges of alternative classifications, data divergence, collaborative contribution mechanisms, and software are outlined. PMID:25941449

  11. Grassroots e-floras in the Poaceae: growing GrassBase and GrassWorld.

    PubMed

    Vorontsova, Maria S; Clayton, Derek; Simon, Bryan K

    2015-01-01

    GrassBase and GrassWorld are the largest structured descriptive datasets in plants, publishing descriptions of 11,290 species in the DELTA format. Twenty nine years of data compilation and maintenance have created a dataset which now underpins much of the Poaceae bioinformatics. GrassBase and GrassWorld can continue to grow productively if the proliferation of alternative classifications and datasets can be brought together into a consensus system. If the datasets are reconciled instead of diverging further apart a long term cumulative process can bring knowledge together for great future utility. This paper presents the Poaceae as the first and largest model system for e-taxonomy and the study of classification development in plants. The origin, development, and content of both datasets is described and key contributors are noted. The challenges of alternative classifications, data divergence, collaborative contribution mechanisms, and software are outlined.

  12. The Prairie Life: The Sea of Grass.

    ERIC Educational Resources Information Center

    Ratzlaff, Harriet

    1996-01-01

    Presents a lesson plan that explores the importance of the environment for 19th-century frontier settlers and the conflict between ranchers and small farmers over appropriate land use. Students watch a video movie, "The Sea of Grass"; read selections from "O Pioneers!"; and write a compare/contrast essay. (MJP)

  13. Basin wildrye: the forgotten grass revisited

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Basin wildrye was once a very abundant and widely occurring species throughout the landscapes of northern Nevada. When Captain Simpson, of the topographical Engineers, explored the route for a wagon road across the central Great Basin he marveled at the grass in the valley bottoms that reached to h...

  14. Common Ground for Managing Invasive Annual Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive annual grasses often reach their full biological potential in ecosystems of the western United States. This suggests that crucial ecosystem "checks and balances" are not functioning. In other words, invasion occurs because ecosystems have lost resistance to invasion, and invasive plants a...

  15. Grass Woman Stories. Blackfeet Heritage Program.

    ERIC Educational Resources Information Center

    Ground, Mary

    During her lifetime Mary Ground, whose Indian name is Grass Woman, has experienced extreme changes in the life of Blackfeet Indians. Born in 1883, she remembers the travois and teepee days as well as the change to reservation life when the reservation was a fenced compound patrolled by the U.S. military. She has seen the decline in the use of…

  16. Challenging Cancer at the Grass Roots.

    ERIC Educational Resources Information Center

    Casto, James E.

    1997-01-01

    The National Cancer Institute created the Appalachia Leadership Initiative on Cancer, composed of four similar projects that focus on increasing screening for cervical and breast cancer among low-income, older women. The program relies on community coalitions that develop innovative grass roots methods to spread the message about the importance of…

  17. Wheatgrass and Wildrye Grasses (Triticeae) (Book Chapter)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheatgrass and wildrye grasses are valued throughout the temperature regions of the world as forage and habitat for livestock and wildlife as well as for other qualities relating to aesthetics, soil stabilization, weed control, and watershed management in semiarid environments. These perennial gras...

  18. INTESPECIIC DIFFERENCES IN GRASS SEED IMBIBITION

    EPA Science Inventory

    Seeds from 12 grass species were studied relative to mode of wetting and time of exposure to water to document interspecific differences in imbibition characteristics. Imbibition causes seeds to become wet, and wet seeds are more detectable to consumers than dry seeds. Thus, ge...

  19. Rangeland and warm-season forage grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock ranchers depend on grassland grazing for a substantial part of their livestock management systems. Grassland forages make up to 85% of the feed supply for ruminant animal products, especially in warm climates. Grass breeding in general creates some unique breeding challenges ranging from...

  20. Heat Shock Proteins in Association with Heat Tolerance in Grasses

    PubMed Central

    Xu, Yan; Zhan, Chenyang; Huang, Bingru

    2011-01-01

    The grass family Poaceae includes annual species cultivated as major grain crops and perennial species cultivated as forage or turf grasses. Heat stress is a primary factor limiting growth and productivity of cool-season grass species and is becoming a more significant problem in the context of global warming. Plants have developed various mechanisms in heat-stress adaptation, including changes in protein metabolism such as the induction of heat shock proteins (HSPs). This paper summarizes the structure and function of major HSPs, recent research progress on the association of HSPs with grass tolerance to heat stress, and incorporation of HSPs in heat-tolerant grass breeding. PMID:22084689

  1. Nowcasting daily minimum air and grass temperature.

    PubMed

    Savage, M J

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient (b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  2. Nowcasting daily minimum air and grass temperature

    NASA Astrophysics Data System (ADS)

    Savage, M. J.

    2016-02-01

    Site-specific and accurate prediction of daily minimum air and grass temperatures, made available online several hours before their occurrence, would be of significant benefit to several economic sectors and for planning human activities. Site-specific and reasonably accurate nowcasts of daily minimum temperature several hours before its occurrence, using measured sub-hourly temperatures hours earlier in the morning as model inputs, was investigated. Various temperature models were tested for their ability to accurately nowcast daily minimum temperatures 2 or 4 h before sunrise. Temperature datasets used for the model nowcasts included sub-hourly grass and grass-surface (infrared) temperatures from one location in South Africa and air temperature from four subtropical sites varying in altitude (USA and South Africa) and from one site in central sub-Saharan Africa. Nowcast models used employed either exponential or square root functions to describe the rate of nighttime temperature decrease but inverted so as to determine the minimum temperature. The models were also applied in near real-time using an open web-based system to display the nowcasts. Extrapolation algorithms for the site-specific nowcasts were also implemented in a datalogger in an innovative and mathematically consistent manner. Comparison of model 1 (exponential) nowcasts vs measured daily minima air temperatures yielded root mean square errors (RMSEs) <1 °C for the 2-h ahead nowcasts. Model 2 (also exponential), for which a constant model coefficient ( b = 2.2) was used, was usually slightly less accurate but still with RMSEs <1 °C. Use of model 3 (square root) yielded increased RMSEs for the 2-h ahead comparisons between nowcasted and measured daily minima air temperature, increasing to 1.4 °C for some sites. For all sites for all models, the comparisons for the 4-h ahead air temperature nowcasts generally yielded increased RMSEs, <2.1 °C. Comparisons for all model nowcasts of the daily grass

  3. Nitrogen fixation associated with grasses in Oregon.

    PubMed

    Nelson, A D; Barber, L E; Tjepkema, J; Russell, S A; Powelson, R; Evans, H J

    1976-04-01

    Nitrogen fixation associated with both natural grasslands and grain crops of Oregon was studied using the acetylene-reduction assay. A number of the grasses collected has some acetylene-reducing activity. Agrostis tenuis Sibth. had substantially greater activity than any of the other species, with a mean rate estimated at 37 g N2 fixed per hectare per day. Assuming 100 days of activity, about 3 kg of N2 would be fixed per hectare per year. This quantity of nitrogen may be important in the maintenance of this species under natural conditions. Nitrogen-fixing microorganisms were isolated from the root surfaces of some of the grasses. Cultures of Bacillus macerans, Bacillus polymyxa, and Enterobacter cloacoa were isolated from wheat roots as were two cultures which have not been assigned a specific taxonomic classification. Strains of N2-fixing Bacillus species and Gram-negative aerobic bacteria were isolated from Festuca and Agrostis.

  4. Acoustic Characterization of Grass-cover Ground

    DTIC Science & Technology

    2014-11-20

    ABSTRACT A custom designed acoustic impedance tube was used to measure acoustic properties ofnonconsolidated materials, specifically soils and grass...covered ground. The tube was config- ured vertically for studying acoustic properties of granular materials i.e. soil and dirt. Software was developed to...collect data and calibrate the impedance tube . An equivalent fluid model for describing sound propagation in rigid fi·ame porous media was used to

  5. Invasive warm-season grasses reduce mycorrhizal root colonization and biomass production of native prairie grasses.

    PubMed

    Wilson, Gail W T; Hickman, Karen R; Williamson, Melinda M

    2012-07-01

    Soil organisms play important roles in regulating ecosystem-level processes and the association of arbuscular mycorrhizal (AM) fungi with a plant species can be a central force shaping plant species' ecology. Understanding how mycorrhizal associations are affected by plant invasions may be a critical aspect of the conservation and restoration of native ecosystems. We examined the competitive ability of old world bluestem, a non-native grass (Caucasian bluestem [Bothriochloa bladhii]), and the influence of B. bladhii competition on AM root colonization of native warm-season prairie grasses (Andropogon gerardii or Schizachyrium scoparium), using a substitutive design greenhouse competition experiment. Competition by the non-native resulted in significantly reduced biomass production and AM colonization of the native grasses. To assess plant-soil feedbacks of B. bladhii and Bothriochloa ischaemum, we conducted a second greenhouse study which examined soil alterations indirectly by assessing biomass production and AM colonization of native warm-season grasses planted into soil collected beneath Bothriochloa spp. This study was conducted using soil from four replicate prairie sites throughout Kansas and Oklahoma, USA. Our results indicate that a major mechanism in plant growth suppression following invasion by Bothriochloa spp. is the alteration in soil microbial communities. Plant growth was tightly correlated with AM root colonization demonstrating that mycorrhizae play an important role in the invasion of these systems by Bothriochloa spp. and indicating that the restoration of native AM fungal communities may be a fundamental consideration for the successful establishment of native grasses into invaded sites.

  6. Retention of Water and Sediment by Grass Strips

    NASA Astrophysics Data System (ADS)

    van Dijk, P. M.; Kwaad, F. J. P. M.; Klapwijk, M.

    1996-08-01

    This paper discusses aspects of grass vegetation in relation to soil erosion control. By means of a literature research, four options for using grass vegetation were recognized, each having its own requirements concerning maintenance, vegetation characteristics and field layout. The main filter mechanisms, application in the field and effects on runoff and soil loss are discussed. Field experiments on filter strips were carried out to determine whether literature data for water and sediment retention by vegetation can be applied to sloping loess soils in South Limburg (The Netherlands). The field experiments simulated a situation in which surface runoff carrying loess sediment from an upslope field enters a grass strip. The retention of water and sediment by grass strips was determined by measuring runoff discharge and the sediment concentration at the inflow and outflow points from bordered plots. Two locations with different grass age and agricultural management were studied. Results show that grass strips are effective in filtering sediment from surface runoff as long as concentrated flow is absent. Outflow sediment concentrations could be described as a function of inflow concentrations and strip width. Reductions of sediment discharge varied between 50-60, 60-90 and 90-99% for strips of 1, 4-5 and 10 m width, respectively. Old grass, extensively used as pasture, is more effective in reducing erosion than the younger grass which was often accessed by tractors for mowing. Differences in water retention between both grass locations appear to be caused mainly by differences in grass density.

  7. Conserved Noncoding Sequences in the Grasses4

    PubMed Central

    Inada, Dan Choffnes; Bashir, Ali; Lee, Chunghau; Thomas, Brian C.; Ko, Cynthia; Goff, Stephen A.; Freeling, Michael

    2003-01-01

    As orthologous genes from related species diverge over time, some sequences are conserved in noncoding regions. In mammals, large phylogenetic footprints, or conserved noncoding sequences (CNSs), are known to be common features of genes. Here we present the first large-scale analysis of plant genes for CNSs. We used maize and rice, maximally diverged members of the grass family of monocots. Using a local sequence alignment set to deliver only significant alignments, we found one or more CNSs in the noncoding regions of the majority of genes studied. Grass genes have dramatically fewer and much smaller CNSs than mammalian genes. Twenty-seven percent of grass gene comparisons revealed no CNSs. Genes functioning in upstream regulatory roles, such as transcription factors, are greatly enriched for CNSs relative to genes encoding enzymes or structural proteins. Further, we show that a CNS cluster in an intron of the knotted1 homeobox gene serves as a site of negative regulation. We showthat CNSs in the adh1 gene do not correlate with known cis-acting sites. We discuss the potential meanings of CNSs and their value as analytical tools and evolutionary characters. We advance the idea that many CNSs function to lock-in gene regulatory decisions. PMID:12952874

  8. Manganese toxicity thresholds for restoration grass species.

    PubMed

    Paschke, Mark W; Valdecantos, Alejandro; Redente, Edward F

    2005-05-01

    Manganese toxicity thresholds for restoration plants have not been established. As a result, ecological risk assessments rely on toxicity thresholds for agronomic species, which may differ from those of restoration species. Our objective was to provide Mn toxicity thresholds for grasses commonly used in restoration. We used a greenhouse screening study where seedlings of redtop, slender wheatgrass, tufted hairgrass, big bluegrass, basin wildrye, and common wheat were grown in sand culture and exposed to increasing concentrations of Mn. The LC50, EC50-plant, EC50-shoot, EC50-root, PT50-shoot, and the PT50-root were then determined. Phytotoxicity thresholds and effective concentrations for the restoration species were generally higher than values reported for agronomic species. Our estimates of PT50-shoot for the five restoration grasses range from 41,528 to 120,082 mg Mn kg(-1). Measures of EC50-plant for these restoration grasses ranged from 877 to >6,000 mg Mn l(-1). These thresholds might be more useful for risk assessors than those based on crop plants that are widely used.

  9. Early inflorescence development in the grasses (Poaceae).

    PubMed

    Kellogg, Elizabeth A; Camara, Paulo E A S; Rudall, Paula J; Ladd, Philip; Malcomber, Simon T; Whipple, Clinton J; Doust, Andrew N

    2013-01-01

    The shoot apical meristem of grasses produces the primary branches of the inflorescence, controlling inflorescence architecture and hence seed production. Whereas leaves are produced in a distichous pattern, with the primordia separated from each other by an angle of 180°, inflorescence branches are produced in a spiral in most species. The morphology and developmental genetics of the shift in phyllotaxis have been studied extensively in maize and rice. However, in wheat, Brachypodium, and oats, all in the grass subfamily Pooideae, the change in phyllotaxis does not occur; primary inflorescence branches are produced distichously. It is unknown whether the distichous inflorescence originated at the base of Pooideae, or whether it appeared several times independently. In this study, we show that Brachyelytrum, the genus sister to all other Pooideae has spiral phyllotaxis in the inflorescence, but that in the remaining 3000+ species of Pooideae, the phyllotaxis is two-ranked. These two-ranked inflorescences are not perfectly symmetrical, and have a clear "front" and "back;" this developmental axis has never been described in the literature and it is unclear what establishes its polarity. Strictly distichous inflorescences appear somewhat later in the evolution of the subfamily. Two-ranked inflorescences also appear in a few grass outgroups and sporadically elsewhere in the family, but unlike in Pooideae do not generally correlate with a major radiation of species. After production of branches, the inflorescence meristem may be converted to a spikelet meristem or may simply abort; this developmental decision appears to be independent of the branching pattern.

  10. Barnyard grass-induced rice allelopathy and momilactone B.

    PubMed

    Kato-Noguchi, Hisashi

    2011-07-01

    Here, we investigated chemical-mediated interaction between crop and weeds. Allelopathic activity of rice seedlings exhibited 5.3-6.3-fold increases when rice and barnyard grass seedlings were grown together, where there may be the competitive interference between rice and barnyard grass for nutrients. Barnyard grass is one of the most noxious weeds in rice cultivation. The momilactone B concentration in rice seedlings incubated with barnyard grass seedlings was 6.9-fold greater than that in rice seedlings incubated independently. Low nutrient growth conditions also increased allelopathic activity and momilactone B concentrations in rice seedlings. However, the increases in the low nutrient-induced allelopathic activity and momilactone B concentration were much lower than those in barnyard grass-induced allelopathic activity and momilactone B concentration. Root exudates of barnyard grass seedlings increased allelopathic activity and momilactone B concentration in rice seedlings at concentrations greater than 30 mg/L of the root exudates, and increasing the exudate concentration increased the activity and momilactone B concentration. Therefore, barnyard grass-induced allelopathic activity of rice seedlings may be caused not only by nutrient competition between two species, but also by components in barnyard grass root exudates. As momilactone B shows strong allelopathic activities, barnyard grass-induced allelopathic activity of rice may be due to the increased concentration of momilactone B in rice seedlings. The present research suggests that rice may respond to the presence of neighboring barnyard grass by sensing the components in barnyard grass root exudates and increasing allelopathic activity by production of elevated concentration of momilactone B. Thus, rice allelopathy may be one of the inducible defense mechanisms by chemical-mediated plant interaction between rice and barnyard grass, and the induced-allelopathy may provide a competitive advantage for

  11. Plant Growth Substances Produced by Azospirillum brasilense and Their Effect on the Growth of Pearl Millet (Pennisetum americanum L.) †

    PubMed Central

    Tien, T. M.; Gaskins, M. H.; Hubbell, D. H.

    1979-01-01

    Azospirillum brasilense, a nitrogen-fixing bacterium found in the rhizosphere of various grass species, was investigated to establish the effect on plant growth of growth substances produced by the bacteria. Thin-layer chromatography, high-pressure liquid chromatography, and bioassay were used to separate and identify plant growth substances produced by the bacteria in liquid culture. Indole acetic acid and indole lactic acid were produced by A. brasilense from tryptophan. Indole acetic acid production increased with increasing tryptophan concentration from 1 to 100 μg/ml. Indole acetic acid concentration also increased with the age of the culture until bacteria reached the stationary phase. Shaking favored the production of indole acetic acid, especially in a medium containing nitrogen. A small but biologically significant amount of gibberellin was detected in the culture medium. Also at least three cytokinin-like substances, equivalent to about 0.001 μg of kinetin per ml, were present. The morphology of pearl millet roots changed when plants in solution culture were inoculated. The number of lateral roots was increased, and all lateral roots were densely covered with root hairs. Experiments with pure plant hormones showed that gibberellin causes increased production of lateral roots. Cytokinin stimulated root hair formation, but reduced lateral root production and elongation of the main root. Combinations of indole acetic acid, gibberellin, and kinetin produced changes in root morphology of pearl millet similar to those produced by inoculation with A. brasilense. Images PMID:16345372

  12. Assessment of Napier millet (Pennisetum purpureumx P. glaucum) and sorghum (Sorghum bicolor) trap crops for the management of Chilo partellus on maize.

    PubMed

    Hari, N S; Jindal, J

    2009-04-01

    Two Napier millet (Pennisetum purpureumxP. glaucum) hybrids, namely PBN 83 and PBN 233 and one sorghum (Sorghum bicolor) variety, SL 44, were assessed for their potential role as a trap crop in the management of the stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) on maize. Oviposition preference and larval survival and development were determined for different test plants under laboratory and screen house conditions. Further, field dispersal of C. partellus larvae was assessed between Napier millet and maize crops. Results from no-choice and dual-choice tests indicated that Napier millet hybrids were preferred for oviposition over maize by C. partellus moths. Sorghum was, however, not preferred over maize in this respect. Napier millet hybrids were poor larval hosts, and a rapid decline in larval numbers was noticed within the first five days after hatching and virtually no larvae survived to pupation. Leaf area eaten by the borer larvae was significantly less on these hybrids than on maize or sorghum. Plant damage was more severe in maize and sorghum than Napier millet hybrids. No appreciable larval shift was noticed from Napier millet hybrids to the adjoining maize crop. The evaluated Napier millet hybrids, therefore, had potential for use as trap crop in C. partellus management. Sorghum, however, did not hold promise in this respect.

  13. Adaptability of Napiergrass (Pennisetum purpureum Schumach.) for Weed Control in Site of Animals Buried after Foot-and-Mouth Disease Infection

    PubMed Central

    Ishii, Yasuyuki; Iki, Yusuke; Inoue, Kouhei; Nagata, Shuhei; Idota, Sachiko; Yokota, Masato; Nishiwaki, Aya

    2016-01-01

    After the infection of foot-and-mouth disease outbreaks in Miyazaki, Japan, in 2010, cattle and swine were slaughtered and buried in a site of 100 ha, where weed control is difficult and costly since lands are unlevelled and prohibited to be plowed for 3 years. To consider the adaptability of napiergrass (Pennisetum purpureum Schumach.) to the animal burial site for weed control, two napiergrass varieties, normal Wruk wona (WK) and dwarf late-heading variety (DL), were transplanted, compared with sowing of maize (MZ) and sorghum (SR) in both burial (BU) and neighboring bordered area (BO) in mid-June 2011. Even though several weed control methods were subjected to lands, MZ and SR failed to be established stably at only 1/3–1/2 due to the suppression of growth by indigenous weeds, while WK and DL successfully established as high as 82–91% and 73–85%, respectively, in 2011. The poor establishment of MZ and SR after sowing tended to be increased with the year from establishment. Plant dry matter yield and cellulose concentration were the highest in WK in 2011, while overwintering ability was constantly higher in DL in the 3 years. It is necessary to consider the utilization of forage plants on the animal burial site. PMID:27274886

  14. Delineation by fluorescence in situ hybridization of a single hemizygous chromosomal region associated with aposporous embryo sac formation in Pennisetum squamulatum and Cenchrus ciliaris.

    PubMed Central

    Goel, Shailendra; Chen, Zhenbang; Conner, Joann A; Akiyama, Yukio; Hanna, Wayne W; Ozias-Akins, Peggy

    2003-01-01

    Apomixis is a means of asexual reproduction by which plants produce embryos without meiosis and fertilization; thus the embryo is of clonal, maternal origin. We previously reported molecular markers showing no recombination with the trait for aposporous embryo sac development in Pennisetum squamulatum and Cenchrus ciliaris, and the collective single-dose alleles defined an apospory-specific genomic region (ASGR). Fluorescence in situ hybridization (FISH) was used to confirm that the ASGR is a hemizygous genomic region and to determine its chromosomal position with respect to rDNA loci and centromere repeats. We also documented chromosome transmission from P. squamulatum in several backcrosses (BCs) with P. glaucum using genomic in situ hybridization (GISH). One to three complete P. squamulatum chromosomes were detected in BC(6), but only one of the three hybridized with the ASGR-linked markers. In P. squamulatum and in all BCs examined, the apospory-linked markers were located in the distal region of the short arm of a single chromosome. All alien chromosomes behaved as univalents during meiosis and segregated randomly in BC(3) and later BC generations, but presence of the ASGR-carrier chromosome alone was sufficient to confer apospory. FISH results support our hypotheses that hemizygosity, proximity to centromeric sequences, and chromosome structure may all play a role in low recombination in the ASGR. PMID:12663545

  15. Adaptability of Napiergrass (Pennisetum purpureum Schumach.) for Weed Control in Site of Animals Buried after Foot-and-Mouth Disease Infection.

    PubMed

    Ishii, Yasuyuki; Iki, Yusuke; Inoue, Kouhei; Nagata, Shuhei; Idota, Sachiko; Yokota, Masato; Nishiwaki, Aya

    2016-01-01

    After the infection of foot-and-mouth disease outbreaks in Miyazaki, Japan, in 2010, cattle and swine were slaughtered and buried in a site of 100 ha, where weed control is difficult and costly since lands are unlevelled and prohibited to be plowed for 3 years. To consider the adaptability of napiergrass (Pennisetum purpureum Schumach.) to the animal burial site for weed control, two napiergrass varieties, normal Wruk wona (WK) and dwarf late-heading variety (DL), were transplanted, compared with sowing of maize (MZ) and sorghum (SR) in both burial (BU) and neighboring bordered area (BO) in mid-June 2011. Even though several weed control methods were subjected to lands, MZ and SR failed to be established stably at only 1/3-1/2 due to the suppression of growth by indigenous weeds, while WK and DL successfully established as high as 82-91% and 73-85%, respectively, in 2011. The poor establishment of MZ and SR after sowing tended to be increased with the year from establishment. Plant dry matter yield and cellulose concentration were the highest in WK in 2011, while overwintering ability was constantly higher in DL in the 3 years. It is necessary to consider the utilization of forage plants on the animal burial site.

  16. Early inflorescence development in the grasses (Poaceae)

    PubMed Central

    Kellogg, Elizabeth A.; Camara, Paulo E. A. S.; Rudall, Paula J.; Ladd, Philip; Malcomber, Simon T.; Whipple, Clinton J.; Doust, Andrew N.

    2013-01-01

    The shoot apical meristem of grasses produces the primary branches of the inflorescence, controlling inflorescence architecture and hence seed production. Whereas leaves are produced in a distichous pattern, with the primordia separated from each other by an angle of 180°, inflorescence branches are produced in a spiral in most species. The morphology and developmental genetics of the shift in phyllotaxis have been studied extensively in maize and rice. However, in wheat, Brachypodium, and oats, all in the grass subfamily Pooideae, the change in phyllotaxis does not occur; primary inflorescence branches are produced distichously. It is unknown whether the distichous inflorescence originated at the base of Pooideae, or whether it appeared several times independently. In this study, we show that Brachyelytrum, the genus sister to all other Pooideae has spiral phyllotaxis in the inflorescence, but that in the remaining 3000+ species of Pooideae, the phyllotaxis is two-ranked. These two-ranked inflorescences are not perfectly symmetrical, and have a clear “front” and “back;” this developmental axis has never been described in the literature and it is unclear what establishes its polarity. Strictly distichous inflorescences appear somewhat later in the evolution of the subfamily. Two-ranked inflorescences also appear in a few grass outgroups and sporadically elsewhere in the family, but unlike in Pooideae do not generally correlate with a major radiation of species. After production of branches, the inflorescence meristem may be converted to a spikelet meristem or may simply abort; this developmental decision appears to be independent of the branching pattern. PMID:23898335

  17. Microwave Scattering Model for Grass Blade Structures

    NASA Technical Reports Server (NTRS)

    Stiles, James M.; Sarabandi, Kamal; Ulaby, Fawwaz T.

    1993-01-01

    In this paper, the electromagnetic scattering solution for a grass blade with complex cross-section geometry is considered. It is assumed that the blade cross section is electrically small, but its length is large compared to the incident wavelength. In a recent study it has been shown that the scattering solution for such problems, in the form of a polarizability tensor, can be obtained using the low-frequency approximation in conjunction with the method of moments. In addition, the study shows that the relationship between the polarizability tensor of a dielectric cylinder and its dielectric constant can be approximated by a simple algebraic expression. The results of this study are used to show that this algebraic approximation is valid also for cylinders with cross sections the shape of grass blades, providing that proper values am selected for each of three constants appearing in the expression. These constants are dependent on cylinder shape, and if the relationship between the constants and the three parameters describing a grass blade shape can be determined, an algebraic approximation relating polarizability tensor to blade shape, as well as dielectric constant, can be formed. Since the elements of the polarizability tensor are dependent on only these parameters, this algebraic approximation can replace the cumbersome method of moments model. A conjugate gradient method is then implemented to correctly determine the three constants of the algebraic approximation for each blade shape. A third-order polynomial fit to the data is then determined for each constant, thus providing a complete analytic replacement to the numerical (moment method) scattering model. Comparisons of this approximation to the numerical model show an average error of less than 3%.

  18. Functional diversity in summer annual grass and legume intercrops in the Northeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A warm-season annual intercropping experiment was conducted across the Northeastern United States with four trials in 2013 and five trials in 2014 with four crop species selected based on differences in stature and nitrogen acquisition traits: 1) pearl millet (Pennisetum glaucum L.); 2) sorghum suda...

  19. Perennial grass dominance: creating a resilient plant community in an exotic annual grass invaded rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Millions of hectares of western rangelands have been invaded by the exotic and invasive annual grass, cheatgrass (Bromus tectorum). Cheatgrass provides a fine-textured, early maturing fuel that has increased the chance, rate, spread and season of wildfire to public and private lands throughout the ...

  20. Insights into the Antiviral Immunity against Grass Carp (Ctenopharyngodon idella) Reovirus (GCRV) in Grass Carp

    PubMed Central

    2015-01-01

    Global fish production from aquaculture has rapidly grown over the past decades, and grass carp shares the largest portion. However, hemorrhagic disease caused by grass carp reovirus (GCRV) results in tremendous loss of grass carp (Ctenopharyngodon idella) industry. During the past years, development of molecular biology and cellular biology technologies has promoted significant advances in the understanding of the pathogen and the immune system. Immunoprophylaxis based on stimulation of the immune system of fish has also got some achievements. In this review, authors summarize the recent progresses in basic researches on GCRV; viral nucleic acid sensors, high-mobility group box proteins (HMGBs); pattern recognition receptors (PRRs), Toll-like receptors (TLRs) and retinoic acid inducible gene I- (RIG-I-) like receptors (RLRs); antiviral immune responses induced by PRRs-mediated signaling cascades of type I interferon (IFN-I) and IFN-stimulated genes (ISGs) activation. The present review also notices the potential applications of molecule genetic markers. Additionally, authors discuss the current preventive and therapeutic strategies (vaccines, RNAi, and prevention medicine) and highlight the importance of innate immunity in long term control for grass carp hemorrhagic disease. PMID:25759845

  1. Salinity tolerance of foxtail barley (Hordeum jubatum) and desirable pasture grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Greenhouse studies were conducted to determine the relative salinity tolerance of foxtail barley and seven desirable pasture grasses. Grass species were reed canarygrass, timothy, altai wildrye, tall fescue, tall wheatgrass, orchardgrass, creeping meadow foxtail, and foxtail barley. Grasses were e...

  2. Recurrent sequence exchange between homeologous grass chromosomes.

    PubMed

    Wicker, Thomas; Wing, Rod A; Schubert, Ingo

    2015-11-01

    All grass species evolved from an ancestor that underwent a whole-genome duplication (WGD) approximately 70 million years ago. Interestingly, the short arms of rice chromosomes 11 and 12 (and independently their homologs in sorghum) were found to be much more similar to each other than other homeologous regions within the duplicated genome. Based on detailed analysis of rice chromosomes 11 and 12 and their homologs in seven grass species, we propose a mechanism that explains the apparently 'younger' age of the duplication in this region of the genome, assuming a small number of reciprocal translocations at the chromosome termini. In each case the translocations were followed by unbalanced transmission and subsequent lineage sorting of the involved chromosomes to offspring. Molecular dating of these translocation events also allowed us to date major chromosome 'fusions' in the evolutionary lineages that led to Brachypodium and Triticeae. Furthermore, we provide evidence that rice is exceptional regarding the evolution of chromosomes 11 and 12, inasmuch as in other species the process of sequence exchange between homeologous chromosomes ceased much earlier than in rice. We presume that random events rather than selective forces are responsible for the observed high similarity between the short arm ends of rice chromosomes 11 and 12.

  3. Temperate grass response to extent and timing of grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Considerable differences exist among cool-season grass species in their production potential and response to management variables. We examined the effects of grazing management on forage and root production of two temperate perennial grasses, meadow fescue [Schedonoruspratensis (Huds.) P. Beauv.] an...

  4. Regional collaborative research on cold tolerance of exotic biofuel grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold tolerance is a selectable trait for many exotic grasses, even those of tropical or subtropical origin. We are conducting cold tolerance assessments on an array of perennial biofuel grasses at Booneville, AR. In study one (published), we reported that two sugarcane clones (US84-1028 and US84-1...

  5. Weed suppression by grasses for orchard floor management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit trees in orchards of the mid-Atlantic region are often planted in vegetation-free rows alternating with grass travel alleys. The tree rows can be maintained vegetation-free by herbicides or tillage but soil degradation or tree injury can result from these practices. Grasses that suppress wee...

  6. Weed suppression by grasses for orchard floor management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit trees in orchards of the mid-Atlantic region of the U.S. are often planted in vegetation-free rows alternating with grass travel alleys. The tree rows can be maintained vegetation-free by herbicides or tillage, but soil degradation or tree injury can result. Grass that is managed to suppress...

  7. Two-dimensional flow patterns near contour grass hedges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grass hedges are narrow strips of stiff-stemmed vegetation used to control erosion and sediment delivery. When planted on the contour, the hydraulic resistance of the vegetation slows runoff, creates ponding, and promotes sediment deposition. In addition, when tillage is performed between grass he...

  8. Narrow grass hedge effects on nutrient transport following compost application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of stiff-stemmed grass hedges can be a valuable soil conservation measure. A study was conducted to measure the effectiveness of a narrow grass hedge, planted on the contour along the hillslope, in reducing runoff nutrient transport from plots with a range of soil nutrient values. Composted ...

  9. Field drying rate differences among three cool-season grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conserving cool-season grasses as silage or hay remains a challenge due to the time required for curing and the unpredictability of weather. We compared the drying rates of three grasses with differing yield potential, morphology, and physical characteristics. Inflorescence-stage meadow fescue, orch...

  10. Assessing Clientele Needs: Designing an Extension Ornamental Grass Bulletin.

    ERIC Educational Resources Information Center

    Gamon, J. A.; And Others

    1993-01-01

    Before designing an extension ornamental grass bulletin, developers surveyed the preferences of a sample of amateurs and professionals on their knowledge of ornamental grasses and their interest in a bulletin on the subject. Results indicated that the same bulletin could serve both groups because no significant differences between the groups were…

  11. Host preference and suitability of grasses for Oebalus pugnax

    PubMed Central

    Awuni, GA; Gore, J; Cook, D; Bond, JA; Musser, FR; Adams, CA

    2014-01-01

    The rice stink bug, Oebalus pugnax (Fabricius) (Hemiptera: Pentatomidae: Carpocorini), though graminaceous, discriminates among its numerous host grass species. This could represent a feeding preference, it could be related to host suitability for growth and development. To clarify the role of host grass discrimination, two laboratory studies were conducted: (1) free-choice tests to evaluate preferences of O. pugnax among 11 wild host grass species found in three rice-producing counties of the central Mississippi Delta (MS, USA), and (2) no-choice tests to evaluate the impact of rice (Oryza sativa L.), junglerice [Echinochloa colona (L.) Link], and dallisgrass (Paspalum dilatatum Poir.) (all Poaceae), on the development of O. pugnax from second instar to adult. In the free-choice test, four experiments were conducted, each with four sets of host grass species and observed 1, 2, 4, 8, and 16 h after release in cages. Approximately 4 h was necessary for O. pugnax to settle on preferred host grasses. Oebalus pugnax showed a feeding preference for junglerice over all 10 other grass species. Bahiagrass, Paspalum notatum Flueggé, was the least preferred. The no-choice tests showed significant effect of host grass species on O. pugnax mean development time of nymphal survival to adults. Survival of nymphs was lower and mean development time was longer on dallisgrass compared to rice and junglerice. Knowledge of O. pugnax rate of growth and development on host grasses could be useful in the future development of rice integrated pest management strategies. PMID:25635144

  12. Grazing invasive annual grasses: the green and brown guide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasion of rangeland by annual grasses has become one of the most serious and catastrophic problems in the western United States. Annual grasses displace desired plants and create monocultures that do not provide adequate plant cover for the entire year. Using the ecologically-based invasive plant ...

  13. Evaluation of strips of centipede grass for sediment load reduction.

    PubMed

    Shiono, Takahiro; Haraguchi, Noburo; Miyamoto, Kuniaki; Shinogi, Yoshiyuki; Miyamoto, Teruhito; Kameyama, Koji

    2008-01-01

    Reddish sediment runoff from agricultural fields results in coastal environmental problems in Okinawa, Japan. Recent studies have demonstrated the effectiveness of strips of centipede grass (Eremochloa ophiuroides (Munro) Hack.), a perennial turf grass, in reducing the sediment loads from farmlands. However, sufficient information has not been provided to determine the appropriate strip specifications in the grass strip design. This study evaluated centipede grass strips for reduction of reddish sediment runoff from farmlands in Okinawa, Japan. A numerical model simulating the reddish sediment transport in the grass strip was constructed to determine the sediment removal efficiency of the strip. The model was verified using data obtained from field plot experiments with the grass strips under natural conditions. The sensitivity analysis of the model showed that the length of the grass strip (i.e. the dimension of the strip in the direction of flow) and unit inflow discharge have a great effect on sediment removal efficiency. The sediment removal efficiency obtained from the model simulation increased with the length of the strip and the increment of the efficiency decreased with the length of the strip. Therefore, these results indicate that the effective and efficient length of a centipede grass strip is 3 m for the reduction of reddish sediment loads under typical farmland conditions in Okinawa.

  14. Genome Sequencing and Analysis of the Model grass Brachypodium distachyon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three subfamilies of grasses, the Ehrhartoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the bulk of human nutrition and are poised to become major sources of renewable energy. Here we describe the genome...

  15. Genome Sequencing and Analysis of the Model Grass Brachypodium Distachyon.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three subfamilies of grasses, the Ehrhartoideae (rice), the Panicoideae (maize, sorghum, sugar cane and millet), and the Pooideae (wheat, barley and cool season forage grasses) provide the basis of human nutrition and are poised to become major sources of renewable energy. Here we describe the compl...

  16. Convection-driven pattern formation in grass (Invited)

    NASA Astrophysics Data System (ADS)

    Daniels, K. E.; Thompson, S. E.

    2010-12-01

    Spatial patterns of 'dead' lawn grass have often been ascribed to Turing-type reaction-diffusion processes related to water scarcity. However, morphologically-similar patterns can also result from fluid convection. Therefore, we present an alternative hypothesis: that the air within the grass canopy is unstable to a convective instability, such that chill damage caused by falling cold air is responsible for the creation of brown and green bands of grass. We model the grass as a uniform porous medium of upright cylindrical rods subject to a temperature gradient and find that the resulting patterns are consistent with several features of small-scale vegetation patterns, including their length scale, rapid onset and transient nature. Finally, the predictions are found to be consistent with measurements made for a particular instance of lawn-patterning in North Carolina. We close by discussing the implications for other plant species. Lawn grass patterning at Duke University.

  17. Native Grass Community Management Plan for the Oak Ridge Reservation

    SciTech Connect

    Ryon, Michael G; Parr, Patricia Dreyer; Cohen, Kari

    2007-06-01

    Land managers at the Department of Energy's Oak Ridge National Laboratory in East Tennessee are restoring native warm-season grasses and wildflowers to various sites across the Oak Ridge Reservation (ORR). Some of the numerous benefits to planting native grasses and forbs include improved habitat quality for wildlife, improved aesthetic values, lower long-term maintenance costs, and compliance with Executive Order 13112 (Clinton 1999). Challenges to restoring native plants on the ORR include the need to gain experience in establishing and maintaining these communities and the potentially greater up-front costs of getting native grasses established. The goals of the native grass program are generally outlined on a fiscal-year basis. An overview of some of the issues associated with the successful and cost-effective establishment and maintenance of native grass and wildflower stands on the ORR is presented in this report.

  18. Methane emission from tropical savanna Trachypogon sp. grasses

    NASA Astrophysics Data System (ADS)

    Sanhueza, E.; Donoso, L.

    2006-11-01

    Methane flux measurements from the soil-grass system were made during the wet season in unperturbed plots and plots where standing dry and green Trachypogon sp. grasses were clipped to just above the soil surface. Results support the surprising discovery that vegetation emits methane. The results of this work allows to infer that the savanna dry/green mixture of grasses produce methane at a rate of ~10 ng m-2 s-1, which is in agreement with early published soil-grass system fluxes. An extrapolation of this flux to the global savanna produces an annual emission much lower than the CH4 production recently suggested in the literature. On the other hand, during the wet season savanna soil consume CH4 at a rate of ~4.7 ng m-2 s-1. Therefore, the tropical savanna soil-grass system would make a modest contribution to the global budget of methane.

  19. Establishing native warm season grasses on Eastern Kentucky strip mines

    SciTech Connect

    Barnes, T.G.; Larkin, J.L.; Arnett, M.B.

    1998-12-31

    The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat.

  20. Effects of Alien Plants on Ecosystem Structure and Functioning and Implications for Restoration: Insights from Three Degraded Sites in South African Fynbos

    NASA Astrophysics Data System (ADS)

    Gaertner, Mirijam; Richardson, David M.; Privett, Sean D. J.

    2011-07-01

    We investigated the type and extent of degradation at three sites on the Agulhas Plain, South Africa: an old field dominated by the alien grass Pennisetum clandestinum Pers . (kikuyu), an abandoned Eucalyptus plantation, and a natural fynbos community invaded by nitrogen fixing—Australian Acacia species. These forms of degradation are representative of many areas in the region. By identifying the nature and degree of ecosystem degradation we aimed to determine appropriate strategies for restoration in this biodiversity hotspot. Vegetation surveys were conducted at degraded sites and carefully selected reference sites. Soil-stored propagule seed banks and macro- and micro-soil nutrients were determined. Species richness, diversity and native cover under Eucalyptus were extremely low compared to the reference site and alterations of the soil nutrients were the most severe. The cover of indigenous species under Acacia did not differ significantly from that in reference sites, but species richness was lower under Acacia and soils were considerably enriched. Native species richness was much lower in the kikuyu site, but soil nutrient status was similar to the reference site. Removal of the alien species alone may be sufficient to re-initiate ecosystem recovery at the kikuyu site, whereas active restoration is required to restore functioning ecosystems dominated by native species in the Acacia thicket and the Eucalyptus plantation. To restore native plant communities we suggest burning, mulching with sawdust and sowing of native species.

  1. Glutathione Peroxidase of Pennisetum glaucum (PgGPx) Is a Functional Cd2+ Dependent Peroxiredoxin that Enhances Tolerance against Salinity and Drought Stress.

    PubMed

    Islam, Tahmina; Manna, Mrinalini; Reddy, Malireddy K

    2015-01-01

    Reactive oxygen species (ROS) arise in the plant system due to inevitable influence of various environmental stimuli. Glutathione peroxidases are one of the important ROS scavengers inside the cell. A glutathione peroxidase (PgGPx) gene was previously found from Pennisetum glauccum abiotic stressed cDNA library. Enzyme kinetics data revealed that PgGPx possessed preference towards thioredoxin rather than glutathione as electron donor and thus belongs to the functional peroxiredoxin group. Moreover, its activity was found to be dependent on divalent cations, especially Cd2+ and homology model showed the presence of Cd2+ binding site in the protein. Site directed mutagenesis study of PgGPx protein revealed the vital role of two conserved Cysteine residues for its enzymatic activity and structural folding. Expression analysis suggested that PgGPx transcript is highly up-regulated in response to salinity and drought stresses. When expressed ectopically, PgGPx showed enhanced tolerance against multiple abiotic stresses in prokaryotic E. coli and model plant, rice. Transgenic rice plants showed lesser accumulation of MDA and H2O2; and higher accumulation of proline as compared to wild type (WT) plants in response to both salinity and drought stresses that clearly indicates suppression of lipid peroxidation and ROS generation in transgenic lines. Moreover, transgenic plants maintained better photosynthesis efficiency and higher level of antioxidant enzyme activity as compared to WT plants under stress conditions. These results clearly indicate the imperative role of PgGPx in cellular redox homeostasis under stress conditions, leading to the maintenance of membrane integrity and increased tolerance towards oxidative stress.

  2. Cereal Domestication and Evolution of Branching: Evidence for Soft Selection in the Tb1 Orthologue of Pearl Millet (Pennisetum glaucum [L.] R. Br.)

    PubMed Central

    Remigereau, Marie-Stanislas; Lakis, Ghayas; Rekima, Samah; Leveugle, Magalie; Fontaine, Michaël C.; Langin, Thierry; Sarr, Aboubakry; Robert, Thierry

    2011-01-01

    Background During the Neolithic revolution, early farmers altered plant development to domesticate crops. Similar traits were often selected independently in different wild species; yet the genetic basis of this parallel phenotypic evolution remains elusive. Plant architecture ranks among these target traits composing the domestication syndrome. We focused on the reduction of branching which occurred in several cereals, an adaptation known to rely on the major gene Teosinte-branched1 (Tb1) in maize. We investigate the role of the Tb1 orthologue (Pgtb1) in the domestication of pearl millet (Pennisetum glaucum), an African outcrossing cereal. Methodology/Principal Findings Gene cloning, expression profiling, QTL mapping and molecular evolution analysis were combined in a comparative approach between pearl millet and maize. Our results in pearl millet support a role for PgTb1 in domestication despite important differences in the genetic basis of branching adaptation in that species compared to maize (e.g. weaker effects of PgTb1). Genetic maps suggest this pattern to be consistent in other cereals with reduced branching (e.g. sorghum, foxtail millet). Moreover, although the adaptive sites underlying domestication were not formerly identified, signatures of selection pointed to putative regulatory regions upstream of both Tb1 orthologues in maize and pearl millet. However, the signature of human selection in the pearl millet Tb1 is much weaker in pearl millet than in maize. Conclusions/Significance Our results suggest that some level of parallel evolution involved at least regions directly upstream of Tb1 for the domestication of pearl millet and maize. This was unanticipated given the multigenic basis of domestication traits and the divergence of wild progenitor species for over 30 million years prior to human selection. We also hypothesized that regular introgression of domestic pearl millet phenotypes by genes from the wild gene pool could explain why the selective

  3. Study through surveys and fermentation kinetics of the traditional processing of pearl millet (Pennisetum glaucum) into ben-saalga, a fermented gruel from Burkina Faso.

    PubMed

    Tou, E H; Guyot, J P; Mouquet-Rivier, C; Rochette, I; Counil, E; Traoré, A S; Trèche, S

    2006-01-15

    Traditional cereal-based fermented foods are frequently used as complementary foods for infants and young children in Africa. This is the case for ben-saalga, a popular fermented gruel produced from pearl millet (Pennisetum glaucum) in Burkina Faso. Detailed knowledge of traditional processing is a prerequisite for investigating ways to improve both the nutritional and sanitary qualities of the corresponding foodstuff. In this work, the traditional processing of pearl millet into ben-saalga was investigated in 24 production units, and fermentation kinetics were studied in pilot scale experiments. Processing steps include: washing (optional), soaking of the grains (first fermentation step), grinding and sieving of the wet flour, settling (second fermentation step), and cooking. The soaking step was mainly characterized by alcoholic fermentation whereas lactic acid fermentation occurred during the settling step. Fermentation kinetics during settling indicates a temporal variation of metabolic activity. Initially, both homofermentative and heterofermentative pathways were simultaneously active, and later only a homofermentative pathway was active. The paste produced at the end of settling had a low pH (4.0+/-0.4) and its microflora was dominated by lactic acid bacteria (LAB) with an amylolytic LAB/LAB ratio of 12%. Sucrose disappeared in the grains during soaking but was not detected in the soaking water, whereas glucose, fructose and maltose appeared transiently. Glucose and fructose were the main substrates observed for lactic acid fermentation during the settling step; however unbalanced fermentation led to the hypothesis that starch hydrolysis products may also serve as substrates for lactic acid formation. At the end of the processing, a 75% and 83% decrease was observed in phytate (IP6) and raffinose, respectively. The sour gruel ben-saalga resulting from cooking the sour paste had inadequate nutritional characteristics with respect to infants' and young

  4. Glutathione Peroxidase of Pennisetum glaucum (PgGPx) Is a Functional Cd2+ Dependent Peroxiredoxin that Enhances Tolerance against Salinity and Drought Stress

    PubMed Central

    Islam, Tahmina; Manna, Mrinalini; Reddy, Malireddy K.

    2015-01-01

    Reactive oxygen species (ROS) arise in the plant system due to inevitable influence of various environmental stimuli. Glutathione peroxidases are one of the important ROS scavengers inside the cell. A glutathione peroxidase (PgGPx) gene was previously found from Pennisetum glauccum abiotic stressed cDNA library. Enzyme kinetics data revealed that PgGPx possessed preference towards thioredoxin rather than glutathione as electron donor and thus belongs to the functional peroxiredoxin group. Moreover, its activity was found to be dependent on divalent cations, especially Cd2+ and homology model showed the presence of Cd2+ binding site in the protein. Site directed mutagenesis study of PgGPx protein revealed the vital role of two conserved Cysteine residues for its enzymatic activity and structural folding. Expression analysis suggested that PgGPx transcript is highly up-regulated in response to salinity and drought stresses. When expressed ectopically, PgGPx showed enhanced tolerance against multiple abiotic stresses in prokaryotic E. coli and model plant, rice. Transgenic rice plants showed lesser accumulation of MDA and H2O2; and higher accumulation of proline as compared to wild type (WT) plants in response to both salinity and drought stresses that clearly indicates suppression of lipid peroxidation and ROS generation in transgenic lines. Moreover, transgenic plants maintained better photosynthesis efficiency and higher level of antioxidant enzyme activity as compared to WT plants under stress conditions. These results clearly indicate the imperative role of PgGPx in cellular redox homeostasis under stress conditions, leading to the maintenance of membrane integrity and increased tolerance towards oxidative stress. PMID:26600014

  5. Resolution of grass canopy biomass classes

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.

    1977-01-01

    Analysis of variance methods has been applied to in situ grassland spectral reflectance data in order to determine the classes or levels of total wet biomass that can be resolved spectrally by a single narrow band measurement. Ground-truth clipping of blue grama grass plots was performed immediately following spectral reflectance measurements at 91 wavelength intervals which were 0.005 microns apart over the spectral range from 0.350 to 0.800 microns. It was found that the photographic infrared region of 0.750 to 0.800 microns could be used to distinguish three classes or levels of total wet biomass. Four or five classes, particularly at higher biomass levels, could not be distinguished by this technique.

  6. N-nitrosamines in grass silages.

    PubMed

    Van Broekhoven, L W; Davies, J A

    1982-01-01

    During the fermentation of silages from nitrate-rich grass, the conditions are suitable for the formation of N-nitrosamines. Earlier investigations had shown that only low concentrations of volatile N-nitrosamines were formed. The first ten days of ensilage were investigated. The formation of nitrite was accompanied by the formation of volatile N-nitrosamines. NDMA and NDEA were detected in concentrations of up to about 2 micrograms/kg. After stabilisation of the silage, these concentrations dropped to about 0.6 microgram/kg. Preliminary results are presented concerning the presence of non-volatile N-nitroso compounds. The method of Walters et al. (1980) indicates that non-volatile N-nitroso compounds were present in amounts equivalent to 85 mg NPIP/kg sample.

  7. Specific immunotherapy for common grass pollen allergies: pertinence of a five grass pollen vaccine.

    PubMed

    Moingeon, Philippe; Hrabina, Maud; Bergmann, Karl-Christian; Jaeger, Siegfried; Frati, Franco; Bordas, Véronique; Peltre, Gabriel

    2008-01-01

    Patients throughout Europe are concomitantly exposed to multiple pollens from distinct Pooideae species. Given the overlap in pollination calendars and similar grain morphology, it is not possible to identify which grass species are present in the environment from pollen counts. Furthermore, neither serum IgE reactivity nor skin prick testing allow the identification of which grass species are involved in patient sensitisation. Due to their high level of amino acid sequence homology (e.g., >90% for group 1, 55-80% for group 5), significant cross-immunogenicity is observed between allergens from Pooideae pollens. Nevertheless, pollen allergens also contain species-specific T or B cell epitopes, and substantial quantitative differences exist in allergen (e.g., groups 1 and 5) composition between pollens from distinct grass species. In this context, a mixture of pollens from common and well-characterised Pooideae such as Anthoxanthum odoratum, Dactylis glomerata, Lolium perenne, Phleum pratense and Poa pratensis is suitable for immunotherapy purposes because (1) it has been validated, both in terms of safety and efficacy, by established clinical practice; (2) it reflects natural exposure and sensitisation conditions; (3) it ensures a consistent and well-balanced composition of critical allergens, thus extending the repertoire of T and B cell epitopes present in the vaccine.

  8. Application of image analysis for grass tillering determination.

    PubMed

    Głąb, Tomasz; Sadowska, Urszula; Żabiński, Andrzej

    2015-11-01

    Tillering is defined as the process of above-ground shoot production by a single plant. The number of grass tillers is one of the most important parameters in ecology and breeding studies. The number of tillers is usually determined by manually counting the separated shoots from a single plant. Unfortunately, this method is too time-consuming. In this study, a new method for counting grass tillers based on image analysis is presented. The usefulness of the method was evaluated for five grass species, Phleum pratense, Lolium perenne, Dactylis glomerata, Festuca pratensis and Bromus unioloides. The grass bunches were prepared for analysis by cutting and tip painting. The images obtained were analysed using an automatic procedure with separation of shoots and other objects based on morphological parameters. It was found that image analysis allows for very quick and accurate counting of grass tillers. However, the set of morphological parameters for object recognition must be selected individually for different grass species. This method can be recommended as a replacement for the traditional, time-consuming method in grass breeding.

  9. Epichloë grass endophytes in sustainable agriculture.

    PubMed

    Kauppinen, Miia; Saikkonen, Kari; Helander, Marjo; Pirttilä, Anna Maria; Wäli, Piippa R

    2016-02-03

    There is an urgent need to create new solutions for sustainable agricultural practices that circumvent the heavy use of fertilizers and pesticides and increase the resilience of agricultural systems to environmental change. Beneficial microbial symbionts of plants are expected to play an important role in integrated pest management schemes over the coming decades. Epichloë endophytes, symbiotic fungi of many grass species, can protect plants against several stressors, and could therefore help to increase the productivity of forage grasses and the hardiness of turf grasses while reducing the use of synthetic pesticides. Indeed, Epichloë endophytes have successfully been developed and commercialized for agricultural use in the USA, Australia and New Zealand. Many of the host grass species originate from Europe, which is a biodiversity hotspot for both grasses and endophytes. However, intentional use of endophyte-enhanced grasses in Europe is virtually non-existent. We suggest that the diversity of European Epichloë endophytes and their host grasses should be exploited for the development of sustainable agricultural, horticultural and landscaping practices, and potentially for bioremediation and bioenergy purposes, and for environmental improvement.

  10. Convection-driven pattern formation in lawn grasses

    NASA Astrophysics Data System (ADS)

    Thompson, Sally; Daniels, Karen

    2009-11-01

    Spatial patterns of 'dead' lawn grass have often been ascribed to Turing-type reaction-diffusion processes related to water scarcity. We present an alternative hypothesis: that the air within the grass canopy is unstable to a convective instability, such that chill damage caused by falling cold air is responsible for the creation of brown and green bands of grass. This hypothesis is consistent with several features of small-scale vegetation patterns, including their length scale, rapid onset and transient nature. We find that the predictions of a porous medium convection model based are consistent with measurements made for a particular instance of lawn-patterning in North Carolina.

  11. Genome sequencing and analysis of the model grass Brachypodium distachyon.

    PubMed

    2010-02-11

    Three subfamilies of grasses, the Ehrhartoideae, Panicoideae and Pooideae, provide the bulk of human nutrition and are poised to become major sources of renewable energy. Here we describe the genome sequence of the wild grass Brachypodium distachyon (Brachypodium), which is, to our knowledge, the first member of the Pooideae subfamily to be sequenced. Comparison of the Brachypodium, rice and sorghum genomes shows a precise history of genome evolution across a broad diversity of the grasses, and establishes a template for analysis of the large genomes of economically important pooid grasses such as wheat. The high-quality genome sequence, coupled with ease of cultivation and transformation, small size and rapid life cycle, will help Brachypodium reach its potential as an important model system for developing new energy and food crops.

  12. How Many Blades of Grass Are on a Football Field?

    ERIC Educational Resources Information Center

    Nugent, Christina M.

    2006-01-01

    This article discusses the use of a problem-based instructional task in an elementary classroom. After estimating the number of blades of grass on a football field, students write letters to explain the results of their research.

  13. 6. WORKERS COLLECTING SAGO PONDWEED, RED TOP GRASS, LEAFY PONDWEED, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. WORKERS COLLECTING SAGO PONDWEED, RED TOP GRASS, LEAFY PONDWEED, WATER MILFOIL, AND OTHER AQUATIC PLANTS FOR TRANSPLANTING FROM A COULEE SIX MILES AWAY FROM THE REFUGE - Upper Souris National Wildlife Refuge Dams, Souris River Basin, Foxholm, Surrey (England), ND

  14. Microwave backscattering and emission model for grass canopies

    NASA Technical Reports Server (NTRS)

    Saatchi, Sasan S.; Lang, Roger H.; Levine, David M.

    1991-01-01

    A two-layer model is developed that treats the grass canopy as a collection of randomly oriented elliptical dielectric discs over a layer of thatch with underlying soil surface. The distorted Born approximation in conjunction with the Peake formulation is used to calculate the backscattering coefficient and the emissivity from the canopy. Two particular features of this model which are unique for grass canopies are the variation of the canopy structure and the presence of the thatch layer. The basic parameters in the model such as the size and orientation of grass blades, dielectric constant of soil and vegetation, and thickness and water content of the thatch layer have been obtained from ground truth data. To interpret the available experimental observations of grasslands, numerical results from both passive and active models at L-band (1.4 GHz) are generated and various scattering and emission properties of the grass canopies are discussed.

  15. Gravity Perception and Response in Shoots of Cereal Grasses

    NASA Technical Reports Server (NTRS)

    Kaufman, P. B.; Song, I.; Bluncson, C.

    1985-01-01

    Two components of the gravitropic curvature response in cereal grass pulvini are studied. These two components are gravity perception and mechanism of response following the transduction phase. The effects of gravity, time lag, protein synthesis and enzyme production are included.

  16. Barnyard grasses were processed with rice around 10000 years ago

    PubMed Central

    Yang, Xiaoyan; Fuller, Dorian Q; Huan, Xiujia; Perry, Linda; Li, Quan; Li, Zhao; Zhang, Jianping; Ma, Zhikun; Zhuang, Yijie; Jiang, Leping; Ge, Yong; Lu, Houyuan

    2015-01-01

    Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual domestication in the Yangtze basin of China. Although both macro-fossils and micro-fossils of rice have been recovered from the Early Neolithic site of Shangshan, dating to more than 10,000 years before present (BP), we report evidence of phytolith and starch microfossils taken from stone tools, both for grinding and cutting, and cultural layers, that indicating barnyard grass (Echinochloa spp.) was a major subsistence resource, alongside smaller quantities of acorn starches (Lithocarpus/Quercus sensu lato) and water chestnuts (Trapa). This evidence suggests that early managed wetland environments were initially harvested for multiple grain species including barnyard grasses as well as rice, and indicate that the emergence of rice as the favoured cultivated grass and ultimately the key domesticate of the Yangtze basin was a protracted process. PMID:26536839

  17. Barnyard grasses were processed with rice around 10000 years ago.

    PubMed

    Yang, Xiaoyan; Fuller, Dorian Q; Huan, Xiujia; Perry, Linda; Li, Quan; Li, Zhao; Zhang, Jianping; Ma, Zhikun; Zhuang, Yijie; Jiang, Leping; Ge, Yong; Lu, Houyuan

    2015-11-05

    Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual domestication in the Yangtze basin of China. Although both macro-fossils and micro-fossils of rice have been recovered from the Early Neolithic site of Shangshan, dating to more than 10,000 years before present (BP), we report evidence of phytolith and starch microfossils taken from stone tools, both for grinding and cutting, and cultural layers, that indicating barnyard grass (Echinochloa spp.) was a major subsistence resource, alongside smaller quantities of acorn starches (Lithocarpus/Quercus sensu lato) and water chestnuts (Trapa). This evidence suggests that early managed wetland environments were initially harvested for multiple grain species including barnyard grasses as well as rice, and indicate that the emergence of rice as the favoured cultivated grass and ultimately the key domesticate of the Yangtze basin was a protracted process.

  18. Methane emission from tropical savanna Trachypogon sp. grasses

    NASA Astrophysics Data System (ADS)

    Sanhueza, E.; Donoso, L.

    2006-07-01

    Methane flux measurements from the soil-grass system were made during the wet season in unperturbed plots and plots where standing dry and green Trachypogon sp. grasses were clipped to just above the soil surface. Results support the surprising discovery that vegetation emits methane. The dry/green mixture of grasses produce methane at a rate of ~10 ng m-2 s-1, which extrapolated to the global savanna would produce an annual emission of ~5 Tg, much lower than the production recently suggested in the literature. On the other hand, during the wet season savanna soil consume CH4 at a rate of ~4.7 ng m-2 s-1, producing a global sink of ~1.3 Tg yr-1. Therefore, the tropical savanna soil-grass system would make a modest contribution to the global budget of methane.

  19. Genome sequencing and analysis of the model grass Brachypodium distachyon

    SciTech Connect

    Yang, Xiaohan; Kalluri, Udaya C; Tuskan, Gerald A

    2010-01-01

    Three subfamilies of grasses, the Ehrhartoideae, Panicoideae and Pooideae, provide the bulk of human nutrition and are poised to become major sources of renewable energy. Here we describe the genome sequence of the wild grass Brachypodium distachyon (Brachypodium), which is, to our knowledge, the first member of the Pooideae subfamily to be sequenced. Comparison of the Brachypodium, rice and sorghum genomes shows a precise history of genome evolution across a broad diversity of the grasses, and establishes a template for analysis of the large genomes of economically important pooid grasses such as wheat. The high-quality genome sequence, coupled with ease of cultivation and transformation, small size and rapid life cycle, will help Brachypodium reach its potential as an important model system for developing new energy and food crops.

  20. INFECTIVITY OF METARHIZIUM ANISOPLIAE IN GRASS SHRIMP EMBRYOS

    EPA Science Inventory

    Developing embryos of the estuarine grass shrimp, Palaemonetes pugio, were exposed to Metarhizium anisopliae conidiospores. Attachment of conidiospores was often followed by germination and outgrowth on embryo surface. Penetration of the embryonic envelopes by M. anisopliae allow...

  1. Variations in Km(CO2) of Ribulose-1,5-bisphosphate Carboxylase among Grasses

    PubMed Central

    Yeoh, Hock-Hin; Badger, Murray R.; Watson, Leslie

    1980-01-01

    A survey of the Km(CO2) values of ribulose-1,5-bisphosphate carboxylase from 60 grass species shows that enzyme from C3 grasses consistently exhibits lower Km(CO2) than does that from C4 grasses. Systematically ordered variation in Km(CO2) of ribulose-1,5-bisphosphate carboxylases from C3 and C4 grasses is also apparent and, among C4 grasses, this shows some correlation with C4 types. PMID:16661586

  2. The Potential of Cellulosic Ethanol Production from Grasses in Thailand

    PubMed Central

    Wongwatanapaiboon, Jinaporn; Kangvansaichol, Kunn; Burapatana, Vorakan; Inochanon, Ratanavalee; Winayanuwattikun, Pakorn; Yongvanich, Tikamporn; Chulalaksananukul, Warawut

    2012-01-01

    The grasses in Thailand were analyzed for the potentiality as the alternative energy crops for cellulosic ethanol production by biological process. The average percentage composition of cellulose, hemicellulose, and lignin in the samples of 18 types of grasses from various provinces was determined as 31.85–38.51, 31.13–42.61, and 3.10–5.64, respectively. The samples were initially pretreated with alkaline peroxide followed by enzymatic hydrolysis to investigate the enzymatic saccharification. The total reducing sugars in most grasses ranging from 500–600 mg/g grasses (70–80% yield) were obtained. Subsequently, 11 types of grasses were selected as feedstocks for the ethanol production by simultaneous saccharification and cofermentation (SSCF). The enzymes, cellulase and xylanase, were utilized for hydrolysis and the yeasts, Saccharomyces cerevisiae and Pichia stipitis, were applied for cofermentation at 35°C for 7 days. From the results, the highest yield of ethanol, 1.14 g/L or 0.14 g/g substrate equivalent to 32.72% of the theoretical values was obtained from Sri Lanka ecotype vetiver grass. When the yields of dry matter were included in the calculations, Sri Lanka ecotype vetiver grass gave the yield of ethanol at 1,091.84 L/ha/year, whereas the leaves of dwarf napier grass showed the maximum yield of 2,720.55 L/ha/year (0.98 g/L or 0.12 g/g substrate equivalent to 30.60% of the theoretical values). PMID:23097596

  3. The potential of cellulosic ethanol production from grasses in Thailand.

    PubMed

    Wongwatanapaiboon, Jinaporn; Kangvansaichol, Kunn; Burapatana, Vorakan; Inochanon, Ratanavalee; Winayanuwattikun, Pakorn; Yongvanich, Tikamporn; Chulalaksananukul, Warawut

    2012-01-01

    The grasses in Thailand were analyzed for the potentiality as the alternative energy crops for cellulosic ethanol production by biological process. The average percentage composition of cellulose, hemicellulose, and lignin in the samples of 18 types of grasses from various provinces was determined as 31.85-38.51, 31.13-42.61, and 3.10-5.64, respectively. The samples were initially pretreated with alkaline peroxide followed by enzymatic hydrolysis to investigate the enzymatic saccharification. The total reducing sugars in most grasses ranging from 500-600 mg/g grasses (70-80% yield) were obtained. Subsequently, 11 types of grasses were selected as feedstocks for the ethanol production by simultaneous saccharification and cofermentation (SSCF). The enzymes, cellulase and xylanase, were utilized for hydrolysis and the yeasts, Saccharomyces cerevisiae and Pichia stipitis, were applied for cofermentation at 35 °C for 7 days. From the results, the highest yield of ethanol, 1.14 g/L or 0.14 g/g substrate equivalent to 32.72% of the theoretical values was obtained from Sri Lanka ecotype vetiver grass. When the yields of dry matter were included in the calculations, Sri Lanka ecotype vetiver grass gave the yield of ethanol at 1,091.84 L/ha/year, whereas the leaves of dwarf napier grass showed the maximum yield of 2,720.55 L/ha/year (0.98 g/L or 0.12 g/g substrate equivalent to 30.60% of the theoretical values).

  4. Pearl millet [Pennisetum glaucum (L.) R. Br.] consensus linkage map constructed using four RIL mapping populations and newly developed EST-SSRs

    PubMed Central

    2013-01-01

    Background Pearl millet [Pennisetum glaucum (L.) R. Br.] is a widely cultivated drought- and high-temperature tolerant C4 cereal grown under dryland, rainfed and irrigated conditions in drought-prone regions of the tropics and sub-tropics of Africa, South Asia and the Americas. It is considered an orphan crop with relatively few genomic and genetic resources. This study was undertaken to increase the EST-based microsatellite marker and genetic resources for this crop to facilitate marker-assisted breeding. Results Newly developed EST-SSR markers (99), along with previously mapped EST-SSR (17), genomic SSR (53) and STS (2) markers, were used to construct linkage maps of four F7 recombinant inbred populations (RIP) based on crosses ICMB 841-P3 × 863B-P2 (RIP A), H 77/833-2 × PRLT 2/89-33 (RIP B), 81B-P6 × ICMP 451-P8 (RIP C) and PT 732B-P2 × P1449-2-P1 (RIP D). Mapped loci numbers were greatest for RIP A (104), followed by RIP B (78), RIP C (64) and RIP D (59). Total map lengths (Haldane) were 615 cM, 690 cM, 428 cM and 276 cM, respectively. A total of 176 loci detected by 171 primer pairs were mapped among the four crosses. A consensus map of 174 loci (899 cM) detected by 169 primer pairs was constructed using MergeMap to integrate the individual linkage maps. Locus order in the consensus map was well conserved for nearly all linkage groups. Eighty-nine EST-SSR marker loci from this consensus map had significant BLAST hits (top hits with e-value ≤ 1E-10) on the genome sequences of rice, foxtail millet, sorghum, maize and Brachypodium with 35, 88, 58, 48 and 38 loci, respectively. Conclusion The consensus map developed in the present study contains the largest set of mapped SSRs reported to date for pearl millet, and represents a major consolidation of existing pearl millet genetic mapping information. This study increased numbers of mapped pearl millet SSR markers by >50%, filling important gaps in previously published SSR-based linkage maps for this

  5. Grassed swales for stormwater pollution control during rain and snowmelt.

    PubMed

    Bäckström, M

    2003-01-01

    The retention of suspended solids, particles and heavy metals in different grassed swales during rain events and snowmelt is discussed. The experimental results derived from investigations performed in existing grassed swales in the Luleå region, Northern Sweden. During high pollutant loading rates, grassed swales retain significant amounts of pollutants, mainly due to sedimentation of particulate matter. Low to moderate removal efficiencies could be expected for heavy metals, especially metals in solution (i.e. the dissolved phase). When grassed swales receive urban runoff with low pollutant concentrations, they may release rather than retain pollutants. Swales are important snow deposit areas in the city and particle bound pollutants do to a large extent remain in the swale after snowmelt. However, dissolved pollutants (i.e. dissolved heavy metals) are likely to escape the swale with the melt water. Grassed swales may be regarded as facilities that even out the peaks in pollutant loads without being capable of producing consistent high removal rates. This suggests that swales should be considered as primary treatment devices. Possible design parameters for grassed swales are mean hydraulic detention time, surface loading rate or specific swale area.

  6. Comparison of trees and grasses for rhizoremediation of petroleum hydrocarbons.

    PubMed

    Cook, Rachel L; Hesterberg, Dean

    2013-01-01

    Rhizoremediation of petroleum contaminants is a phytoremediation process that depends on interactions among plants, microbes, and soils. Trees and grasses are commonly used for phytoremediation, with trees typically being chosen for remediation of BTEX while grasses are more commonly used for remediation of PAHs and total petroleum hydrocarbons. The objective of this review was to compare the effectiveness of trees and grasses for rhizoremediation of hydrocarbons and address the advantages of each vegetation type. Grasses were more heavily represented in the literature and therefore demonstrated a wider range of effectiveness. However, the greater biomass and depth of tree roots may have greater potential for promoting environmental conditions that can improve rhizoremediation, such as increased metabolizable organic carbon, oxygen, and water. Overall, we found little difference between grasses and trees with respect to average reduction of hydrocarbons for studies that compared planted treatments with a control. Additional detailed investigations into plant attributes that most influence hydrocarbon degradation rates should provide data needed to determine the potential for rhizoremediation with trees or grasses for a given site and identify which plant characteristics are most important.

  7. Outbreaks of equine grass sickness in Hungary.

    PubMed

    Schwarz, B; Brunthaler, R; Hahn, C; van den Hoven, R

    2012-01-21

    Equine grass sickness (EGS) occurs mainly in Great Britain, but has once been reported in Hungary. The stud which was affected by EGS in 2001 had no new cases until 2009/10, when 11 of 60 and five of 12 one- to three-year-old colts died or were euthanased due to EGS. Following a few hours in the high-risk field during the winter of 2010/11 further four cases of acute EGS were noted among these horses. The affected horses showed somewhat different clinical signs compared with the cases reported in Great Britain. Histopathological findings in these horses were consistent with EGS. In most examined cases carbofuran, a carbamate was found in the liver by toxicological examination, and it is postulated that carbofuran may influence the immune system and therefore predispose the horses to develop EGS. Carbamates are thought to cause a delayed neurotoxicity in human beings. Further studies are needed to clarify the potential role of carbamates in EGS.

  8. Evaluation of warm-season grass nutritive value as an alternative to cool-season grass under limited irrigation in the semi-arid western United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The production of cool-season grasses is limited by their photosynthetic inefficiency during the hot summer months. Therefore, a study was conducted during 2006 and 2007 at a Logan, UT, USA field site to determine the potential of various warm-season grasses as alternatives to cool-season grass dur...

  9. Greenhouse gas flux under warm-season perennial C4 grasses across different soil and climate gradients on the Islands of Hawaii

    NASA Astrophysics Data System (ADS)

    Pawlowski, M. N.; Crow, S. E.; Sumiyoshi, Y.; Wells, J.; Kikkawa, H. R.

    2011-12-01

    Agricultural soils can serve as either a sink or a source for atmospheric carbon (C) and other greenhouse gases (GHG). This is particularly true for tropical soils where influences from climate and soil gradients are wide ranging. Current estimates of GHG flux from soil are often under or overestimated due to high variability in sample sites and inconsistencies in land use and vegetation type, making extrapolation to new study systems difficult. This work aimed to identify patterns of trace fluxes of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) across two soil types and three species of warm season perennial C4 grasses: Pennisetum purpureum (Napier grass), Panicum maximum (Guinea grass) and Saccharum officinarum (sugar cane) on the islands of Oahu and Maui in Hawaii. Multiple static vented chambers were installed into replicate plots for each species; flux measurements were made during the growth, fertilization and harvest cycles at set time intervals for one hour and analyzed by gas chromatography. Initial results from Oahu indicate no significant differences in CO2 flux between the P. maximum and P. purpureum species after fertilization or at full growth. We observed an average flux of 143 mg m-2 h-1 and 155 mg m-2 h-1 for P. maximum and P. purpureum respectively at full growth for CO2 and 1.7 μg m-2 h-1and 0.3 μg m-2 h-1 for N2O. Additionally, N2O rates sampled after a typical fertilizer application were significantly greater than at full growth (p=0.0005) with flux rates of 25.2 μg m2h-1 and 30.3 μg m2h-1 for P. maximum and P. purpureum respectively. With a global warming potential of 310 for N2O, even short-term spikes following fertilizer application can cause long lasting effects of GHG emission from agricultural soils. CH4 flux was negligible for all species on the Oahu plots during these sample periods. Globally, water limitation is a major factor influencing the potential productivity of agricultural crops and the sustainability of

  10. GRASS GIS: The first Open Source Temporal GIS

    NASA Astrophysics Data System (ADS)

    Gebbert, Sören; Leppelt, Thomas

    2015-04-01

    GRASS GIS is a full featured, general purpose Open Source geographic information system (GIS) with raster, 3D raster and vector processing support[1]. Recently, time was introduced as a new dimension that transformed GRASS GIS into the first Open Source temporal GIS with comprehensive spatio-temporal analysis, processing and visualization capabilities[2]. New spatio-temporal data types were introduced in GRASS GIS version 7, to manage raster, 3D raster and vector time series. These new data types are called space time datasets. They are designed to efficiently handle hundreds of thousands of time stamped raster, 3D raster and vector map layers of any size. Time stamps can be defined as time intervals or time instances in Gregorian calendar time or relative time. Space time datasets are simplifying the processing and analysis of large time series in GRASS GIS, since these new data types are used as input and output parameter in temporal modules. The handling of space time datasets is therefore equal to the handling of raster, 3D raster and vector map layers in GRASS GIS. A new dedicated Python library, the GRASS GIS Temporal Framework, was designed to implement the spatio-temporal data types and their management. The framework provides the functionality to efficiently handle hundreds of thousands of time stamped map layers and their spatio-temporal topological relations. The framework supports reasoning based on the temporal granularity of space time datasets as well as their temporal topology. It was designed in conjunction with the PyGRASS [3] library to support parallel processing of large datasets, that has a long tradition in GRASS GIS [4,5]. We will present a subset of more than 40 temporal modules that were implemented based on the GRASS GIS Temporal Framework, PyGRASS and the GRASS GIS Python scripting library. These modules provide a comprehensive temporal GIS tool set. The functionality range from space time dataset and time stamped map layer management

  11. [Optimized Spectral Indices Based Estimation of Forage Grass Biomass].

    PubMed

    An, Hai-bo; Li, Fei; Zhao, Meng-li; Liu, Ya-jun

    2015-11-01

    As an important indicator of forage production, aboveground biomass will directly illustrate the growth of forage grass. Therefore, Real-time monitoring biomass of forage grass play a crucial role in performing suitable grazing and management in artificial and natural grassland. However, traditional sampling and measuring are time-consuming and labor-intensive. Recently, development of hyperspectral remote sensing provides the feasibility in timely and nondestructive deriving biomass of forage grass. In the present study, the main objectives were to explore the robustness of published and optimized spectral indices in estimating biomass of forage grass in natural and artificial pasture. The natural pasture with four grazing density (control, light grazing, moderate grazing and high grazing) was designed in desert steppe, and different forage cultivars with different N rate were conducted in artificial forage fields in Inner Mongolia. The canopy reflectance and biomass in each plot were measured during critical stages. The result showed that, due to the influence in canopy structure and biomass, the canopy reflectance have a great difference in different type of forage grass. The best performing spectral index varied in different species of forage grass with different treatments (R² = 0.00-0.69). The predictive ability of spectral indices decreased under low biomass of desert steppe, while red band based spectral indices lost sensitivity under moderate-high biomass of forage maize. When band combinations of simple ratio and normalized difference spectral indices were optimized in combined datasets of natural and artificial grassland, optimized spectral indices significant increased predictive ability and the model between biomass and optimized spectral indices had the highest R² (R² = 0.72) compared to published spectral indices. Sensitive analysis further confirmed that the optimized index had the lowest noise equivalent and were the best performing index in

  12. Phylogenetic analyses reveal the shady history of C4 grasses.

    PubMed

    Edwards, Erika J; Smith, Stephen A

    2010-02-09

    Grasslands cover more than 20% of the Earth's terrestrial surface, and their rise to dominance is one of the most dramatic events of biome evolution in Earth history. Grasses possess two main photosynthetic pathways: the C(3) pathway that is typical of most plants and a specialized C(4) pathway that minimizes photorespiration and thus increases photosynthetic performance in high-temperature and/or low-CO(2) environments. C(4) grasses dominate tropical and subtropical grasslands and savannas, and C(3) grasses dominate the world's cooler temperate grassland regions. This striking pattern has been attributed to C(4) physiology, with the implication that the evolution of the pathway enabled C(4) grasses to persist in warmer climates than their C(3) relatives. We combined geospatial and molecular sequence data from two public archives to produce a 1,230-taxon phylogeny of the grasses with accompanying climate data for all species, extracted from more than 1.1 million herbarium specimens. Here we show that grasses are ancestrally a warm-adapted clade and that C(4) evolution was not correlated with shifts between temperate and tropical biomes. Instead, 18 of 20 inferred C(4) origins were correlated with marked reductions in mean annual precipitation. These changes are consistent with a shift out of tropical forest environments and into tropical woodland/savanna systems. We conclude that C(4) evolution in grasses coincided largely with migration out of the understory and into open-canopy environments. Furthermore, we argue that the evolution of cold tolerance in certain C(3) lineages is an overlooked innovation that has profoundly influenced the patterning of grassland communities across the globe.

  13. Phylogenetic analyses reveal the shady history of C4 grasses

    PubMed Central

    Edwards, Erika J.; Smith, Stephen A.

    2010-01-01

    Grasslands cover more than 20% of the Earth's terrestrial surface, and their rise to dominance is one of the most dramatic events of biome evolution in Earth history. Grasses possess two main photosynthetic pathways: the C3 pathway that is typical of most plants and a specialized C4 pathway that minimizes photorespiration and thus increases photosynthetic performance in high-temperature and/or low-CO2 environments. C4 grasses dominate tropical and subtropical grasslands and savannas, and C3 grasses dominate the world's cooler temperate grassland regions. This striking pattern has been attributed to C4 physiology, with the implication that the evolution of the pathway enabled C4 grasses to persist in warmer climates than their C3 relatives. We combined geospatial and molecular sequence data from two public archives to produce a 1,230-taxon phylogeny of the grasses with accompanying climate data for all species, extracted from more than 1.1 million herbarium specimens. Here we show that grasses are ancestrally a warm-adapted clade and that C4 evolution was not correlated with shifts between temperate and tropical biomes. Instead, 18 of 20 inferred C4 origins were correlated with marked reductions in mean annual precipitation. These changes are consistent with a shift out of tropical forest environments and into tropical woodland/savanna systems. We conclude that C4 evolution in grasses coincided largely with migration out of the understory and into open-canopy environments. Furthermore, we argue that the evolution of cold tolerance in certain C3 lineages is an overlooked innovation that has profoundly influenced the patterning of grassland communities across the globe. PMID:20142480

  14. Nitrogen losses from perennial grass species.

    PubMed

    Vázquez de Aldana, B R; Geerts, R H E M; Berendse, F

    1996-04-01

    Nitrogen losses from plants may occur through a variety of pathways, but so far, most studies have only quantified losses of nutrients by above-ground litter production. We used (15)N pulse labelling to quantify total nitrogen losses from above- and below-ground plant parts. Using this method we were able to include also pathways other than above-ground litter production. To test the hypothesis that species from nutrient-poor habitats lose less nitrogen than species from more fertile soils, six perennial grasses from habitats with a wide range of nutrient availability were investigated: Lolium perenne, Arrhenatherum elatius, Anthoxanthum odoratum, Festuca rubra, F. ovina and Molinia caerulea. The results of an experiment carried out in pots in a green-house at two fertility levels show that statistically significant losses occur through pathways other than above-ground litter production. In the low fertility treatment, most (70%) losses from L. perenne occurred by litter production, but in Ar. elatius, F. rubra, F. ovina and M. caerulea, more than 50% of labelled N losses took place by root turn-over, leaching or exudation from roots. When nutrient supply increased, the (15)N losses in above-ground dead material increased in all species and in Ar. elatius, A. odoratum and F. rubra the (15)N losses via other pathways decreased. Ranked according to decreasing turnover coefficient the sequence of species was: L. perenne, A. odoratum, F. rubra, F. ovina, Ar. elatius, M. caerulea. These results suggest that species adapted to sites with low availability of nutrients lose less nitrogen (including above- and below-ground losses) than species adapted to more fertile soils.

  15. Remote sensing of St. Augustine Decline (SAD) disease. [spectral reflectance of healthy and diseased grass

    NASA Technical Reports Server (NTRS)

    Odle, W. C.

    1976-01-01

    Laboratory and field spectral reflectance measurements of healthy and infected St. Augustine grass were made using several different instruments. Spectral differences between healthy and infected grass occured in the visible and near infrared regions. Multiband and color infrared photographs were taken of healthy and diseased turf from ground-based platforms and low altitude aircraft. Qualitative (density slicing) and quantitative (transmission densitometry) analyses revealed distinct tonal differences between healthy and St. Augustine disease (SAD) infected grass. Similar experiments are described for determining if healthy and diseased grass can be distinguished from waterstressed grass and grass deficient in either nitrogen or iron.

  16. Performance of West African dwarf goats fed Guinea grass-Verano stylo mixture, N-fertilized and unfertilized Guinea grass.

    PubMed

    Bamikole, M A.; Ezenwa, I; Akinsoyinu, A O.; Arigbede, M O.; Babayemi, O J.

    2001-02-01

    The supplementary values of Verano stylo in a mixed Guinea grass (Panicum maximum cv. Ntchisi)-Verano stylo (Stylosanthes hamata cv. Verano) diet from a sown grass-legume mixture and N fertilized grass were compared in West African dwarf (WAD) goats. Liveweight (LW) gain, feed intake, digestibility and N utilization were determined using 15 goats in two trials lasting for 98 days. Goats were fed Guinea grass-Verano stylo mixture (GSM), N-fertilized (NFG) and unfertilized grass (UFG). The goats were divided into three groups of five animals each and randomly allocated to the dietary treatments in a randomized complete block design. Total DM and OM intakes of the goats did not vary significantly among the forage diets and averaged 55.1 and 50.4gkg(-1)W(0.75) per day, respectively. CP intake (gkg(-1)W(0.75) per day) was highest with NFG (5.6) followed by GSM (4.8) and the UFG (3.5). Total N excreted followed the same trend as the CP intake. There was no significant difference between N-retention of GSM and NFG (28.5 and 26.7%), but goats on UFG had a negative N balance (-9.16%). Animals on GSM had significantly higher liveweight gain (31.9g per day) than those of NFG (25.1g per day) and UFG (21.9g per day) which also differed significantly. The digestibilities of total DM, OM, CP, NDF were higher with GSM than NFG or UFG. It is concluded that growing Verano stylo in mixture with Guinea grass is a better option for improving the feed quality of forage diets for goats than direct application of inorganic fertilizer at 200kgNha(-1) to the pure grass.

  17. Designing hybrid grass genomes to control runoff generation

    NASA Astrophysics Data System (ADS)

    MacLeod, C.; Binley, A.; Humphreys, M.; King, I. P.; O'Donovan, S.; Papadopoulos, A.; Turner, L. B.; Watts, C.; Whalley, W. R.; Haygarth, P.

    2010-12-01

    Sustainable management of water in landscapes requires balancing demands of agricultural production whilst moderating downstream effects like flooding. Pasture comprises 69% of global agricultural areas and is essential for producing food and fibre alongside environmental goods and services. Thus there is a need to breed forage grasses that deliver multiple benefits through increased levels of productivity whilst moderating fluxes of water. Here we show that a novel grass hybrid that combines the entire genomes of perennial ryegrass (Lolium perenne - the grass of choice for Europe’s forage agriculture) and meadow fescue (Festuca pratensis) has a significant role in flood prevention. Field plot experiments established differences in runoff generation with the hybrid cultivar reducing runoff by 50% compared to perennial ryegrass cultivar, and by 35% compared to a meadow fescue cultivar (34 events over two years, replicated randomized-block design, statistically significant differences). This important research outcome was the result of a project that combined plant genetics, soil physics and plot scale hydrology to identify novel grass genotypes that can reduce runoff from grassland systems. Through a coordinated series of experiments examining effects from the gene to plot scale, we have identified that the rapid growth and then turnover of roots in the L. perenne x F. pratensis hybrid is likely to be a key mechanism in reducing runoff generation. More broadly this is an exciting first step to realizing the potential to design grass genomes to achieve both food production, and to deliver flood control, a key ecosystem service.

  18. Salt tolerance evolves more frequently in C4 grass lineages.

    PubMed

    Bromham, L; Bennett, T H

    2014-03-01

    Salt tolerance has evolved many times in the grass family, and yet few cereal crops are salt tolerant. Why has it been so difficult to develop crops tolerant of saline soils when salt tolerance has evolved so frequently in nature? One possible explanation is that some grass lineages have traits that predispose them to developing salt tolerance and that without these background traits, salt tolerance is harder to achieve. One candidate background trait is photosynthetic pathway, which has also been remarkably labile in grasses. At least 22 independent origins of the C4 photosynthetic pathway have been suggested to occur within the grass family. It is possible that the evolution of C4 photosynthesis aids exploitation of saline environments, because it reduces transpiration, increases water-use efficiency and limits the uptake of toxic ions. But the observed link between the evolution of C4 photosynthesis and salt tolerance could simply be due to biases in phylogenetic distribution of halophytes or C4 species. Here, we use a phylogenetic analysis to investigate the association between photosynthetic pathway and salt tolerance in the grass family Poaceae. We find that salt tolerance is significantly more likely to occur in lineages with C4 photosynthesis than in C3 lineages. We discuss the possible links between C4 photosynthesis and salt tolerance and consider the limitations of inferring the direction of causality of this relationship.

  19. Grass meristems II: inflorescence architecture, flower development and meristem fate.

    PubMed

    Tanaka, Wakana; Pautler, Michael; Jackson, David; Hirano, Hiro-Yuki

    2013-03-01

    Plant development depends on the activity of various types of meristems that generate organs such as leaves and floral organs throughout the life cycle. Grass species produce complex inflorescences and unique flowers. The grass inflorescence is composed of different types of branches, including a specialized branch called a spikelet. The spikelet is a special unit of the inflorescence and forms one to several florets, depending on the species. In the floret, floral organs such as perianth organs, carpels and stamens are formed. In Arabidopsis, because the inflorescence meristem (IM) forms the floral meristems (FMs) directly on its flanks, the change of meristem fate is relatively simple. In contrast, in grasses, different types of meristem, such as the IM, the branch meristem (BM), the spikelet pair meristem (SPM) in some grasses, the spikelet meristem (SM) and the FM, are responsible for the elaboration of their complex inflorescences and flowers. Therefore, sequential changes of meristem fate are required, and a number of genes involved in the specification of the fate of each meristem have been identified. In this review, we focus on the following issues concerning the fate of the reproductive meristems in two grass species, maize (Zea mays) and rice (Oryza sativa): (i) meristem regulation during inflorescence development; (ii) specification and fate change of the BM and the SM; (iii) determinacy of the FM; and (iv) communication between the meristem and lateral organs.

  20. TILLING in forage grasses for gene discovery and breeding improvement.

    PubMed

    Manzanares, Chloe; Yates, Steven; Ruckle, Michael; Nay, Michelle; Studer, Bruno

    2016-09-25

    Mutation breeding has a long-standing history and in some major crop species, many of the most important cultivars have their origin in germplasm generated by mutation induction. For almost two decades, methods for TILLING (Targeting Induced Local Lesions IN Genomes) have been established in model plant species such as Arabidopsis (Arabidopsis thaliana L.), enabling the functional analysis of genes. Recent advances in mutation detection by second generation sequencing technology have brought its utility to major crop species. However, it has remained difficult to apply similar approaches in forage and turf grasses, mainly due to their outbreeding nature maintained by an efficient self-incompatibility system. Starting with a description of the extent to which traditional mutagenesis methods have contributed to crop yield increase in the past, this review focuses on technological approaches to implement TILLING-based strategies for the improvement of forage grass breeding through forward and reverse genetics. We present first results from TILLING in allogamous forage grasses for traits such as stress tolerance and evaluate prospects for rapid implementation of beneficial alleles to forage grass breeding. In conclusion, large-scale induced mutation resources, used for forward genetic screens, constitute a valuable tool to increase the genetic diversity for breeding and can be generated with relatively small investments in forage grasses. Furthermore, large libraries of sequenced mutations can be readily established, providing enhanced opportunities to discover mutations in genes controlling traits of agricultural importance and to study gene functions by reverse genetics.

  1. Heavy metal levels of pasture grasses in metropolitan area

    NASA Astrophysics Data System (ADS)

    Luilo, G. B.; Othman, O. C.

    2003-05-01

    Urban agriculture is becoming an important lucrative activity in Dar es Salaam City even though the city is subject to traffic and industrial pollution pressures. Poor planning has left only limited spaces, particularly road reserves, for cultivation and foraging animals. While there is increasing road traffic no study bas been conducted determine levels of trace metals in pasture grasses. This study, therefore, reports on the levels of cadmium, manganese, lead and zinc of cynodon grasses in road vicinity in the city. Results show that the trace metal levels (ppm ± SDE) in Cynodon grass species were: Cd (0.24 ± 0.06-2.58 ± 0.15), Mn (41.5 ± 13.6-345.0 ± 124.3), Pb (1.15 ± 0.64-25.53 ± 1.29) and Zn (25.97 ± 3.69-95.36 ± 19.61). The mean levels of lead and zinc varied exponentially with distance off the road up to 15 m distance. Lead and zinc levels correlated with average daily traffic in the roads while cadmium and manganese did not. This suggests that lead and zinc in grasses owe their sources from the passing motor vehicles in agreement with other reported studies. It is recommended that pasture grasses in road vicinities must not be used for foraging dairy cattle and goats for public health reasons.

  2. Mismatch in aeroallergens and airborne grass pollen concentrations

    NASA Astrophysics Data System (ADS)

    Plaza, M. P.; Alcázar, P.; Hernández-Ceballos, M. A.; Galán, C.

    2016-11-01

    An accurate estimation of the allergen concentration in the atmosphere is essential for allergy sufferers. The major cause of pollinosis all over Europe is due to grass pollen and Phl p 5 has the highest rates of sensitization (>50%) in patients with grass pollen-induced allergy. However, recent research has shown that airborne pollen does not always offer a clear indicator of exposure to aeroallergens. This study aims to evaluate relations between airborne grass pollen and Phl p 5 concentrations in Córdoba (southern Spain) and to study how meteorological parameters influence these atmospheric records. Monitoring was carried out from 2012 to 2014. Hirst-type volumetric spore trap was used for pollen collection, following the protocol recommended by the Spanish Aerobiology Network (REA). Aeroallergen sampling was performed using a low-volume cyclone sampler, and allergenic particles were quantified by ELISA assay. Besides, the influence of main meteorological factors on local airborne pollen and allergen concentrations was surveyed. A significant correlation was observed between grass pollen and Phl p 5 allergen concentrations during the pollen season, but with some sporadic discrepancy episodes. The cumulative annual Pollen Index also varied considerably. A significant correlation has been obtained between airborne pollen and minimum temperature, relative humidity and precipitation, during the three studied years. However, there is no clear relationship between allergens and weather variables. Our findings suggest that the correlation between grass pollen and aeroallergen Phl p 5 concentrations varies from year-to-year probably related to a complex interplay of meteorological variables.

  3. Silicified structures affect leaf optical properties in grasses and sedge.

    PubMed

    Klančnik, Katja; Vogel-Mikuš, Katarina; Gaberščik, Alenka

    2014-01-05

    Silicon (Si) is an important structural element that can accumulate at high concentrations in grasses and sedges, and therefore Si structures might affect the optical properties of the leaves. To better understand the role of Si in light/leaf interactions in species rich in Si, we examined the total Si and silica phytoliths, the biochemical and morphological leaf properties, and the reflectance and transmittance spectra in grasses (Phragmites australis, Phalaris arundinacea, Molinia caerulea, Deschampsia cespitosa) and sedge (Carex elata). We show that these grasses contain >1% phytoliths per dry mass, while the sedge contains only 0.4%. The data reveal the variable leaf structures of these species and significant differences in the amount of Si and phytoliths between developing and mature leaves within each species and between grasses and sedge, with little difference seen among the grass species. Redundancy analysis shows the significant roles of the different near-surface silicified leaf structures (e.g., prickle hairs, cuticle, epidermis), phytoliths and Si contents, which explain the majority of the reflectance and transmittance spectra variability. The amount of explained variance differs between mature and developing leaves. The transmittance spectra are also significantly affected by chlorophyll a content and calcium levels in the leaf tissue.

  4. Ensilage of tropical grasses mixed with legumes and molasses.

    PubMed

    Tjandraatmadja, M; Norton, B W; Mac Rae, I C

    1994-01-01

    The effects of adding two legumes, Gliricidia sepium and Leucaena leucocephala, cv. Cunningham, and molasses on the fermentation characteristics of silages made from two tropical grasses (Pangola grass, Digitaria decumbens, and Setaria sphacelata cv. Kazungula) were investigated. Pangola grass silages contained significantly higher contents of water-soluble carbohydrates and lactic acid than did setaria silages after 100 days fermentation, but there were no significant differences between the two silages in populations of lactic acid bacteria and contents of total N and NH3-N. Addition of either species of legume had no significant effect on fermentation acids and NH3-N contents, and numbers of lactic acid bacteria. Addition of both legumes reduced NH3-N production in the silages by 59% after 5 days' fermentation. Numbers of lactic acid bacteria were not significantly affected by the different treatments. Enterococcus faecalis represented 60% of the lactic acid bacteria isolated from the treated herbages prior to ensiling. By 100 days of fermentation, only lactobacilli were isolated: 82% homo-fermenters and 18% hetero-fermenters. Lactobacillus mesenteroides subsp. dextranicum was found only in the silage supplemented with 33% (w/w) legume. It was concluded that the low quality of tropical grasses used as feeds for ruminants may be significantly improved by ensiling these grasses with small amounts of molasses and with high-protein tree leaves.

  5. Enhanced precipitation variability decreases grass- and increases shrub-productivity.

    PubMed

    Gherardi, Laureano A; Sala, Osvaldo E

    2015-10-13

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society.

  6. Enhanced precipitation variability decreases grass- and increases shrub-productivity

    PubMed Central

    Gherardi, Laureano A.; Sala, Osvaldo E.

    2015-01-01

    Although projections of precipitation change indicate increases in variability, most studies of impacts of climate change on ecosystems focused on effects of changes in amount of precipitation, overlooking precipitation variability effects, especially at the interannual scale. Here, we present results from a 6-y field experiment, where we applied sequences of wet and dry years, increasing interannual precipitation coefficient of variation while maintaining a precipitation amount constant. Increased precipitation variability significantly reduced ecosystem primary production. Dominant plant-functional types showed opposite responses: perennial-grass productivity decreased by 81%, whereas shrub productivity increased by 67%. This pattern was explained by different nonlinear responses to precipitation. Grass productivity presented a saturating response to precipitation where dry years had a larger negative effect than the positive effects of wet years. In contrast, shrubs showed an increasing response to precipitation that resulted in an increase in average productivity with increasing precipitation variability. In addition, the effects of precipitation variation increased through time. We argue that the differential responses of grasses and shrubs to precipitation variability and the amplification of this phenomenon through time result from contrasting root distributions of grasses and shrubs and competitive interactions among plant types, confirmed by structural equation analysis. Under drought conditions, grasses reduce their abundance and their ability to absorb water that then is transferred to deep soil layers that are exclusively explored by shrubs. Our work addresses an understudied dimension of climate change that might lead to widespread shrub encroachment reducing the provisioning of ecosystem services to society. PMID:26417095

  7. Indirect effects of an invasive annual grass on seed fates of two native perennial grass species.

    PubMed

    Meyer, Susan E; Merrill, Katherine T; Allen, Phil S; Beckstead, Julie; Norte, Anna S

    2014-04-01

    Invasive plants exhibit both direct and indirect negative effects on recruitment of natives following invasion. We examined indirect effects of the invader Bromus tectorum (cheatgrass) on seed fates of two native grass species, Elymus elymoides and Pseudoroegneria spicata, by removing B. tectorum and by adding inoculum of the shared seed pathogen Pyrenophora semeniperda in factorial experiments at xeric and mesic field sites. We also included a supplemental watering treatment to increase emergence and also the potential for pathogen escape. We recorded emergence and survival of native seedlings and also determined the fate of unemerged seeds. At the xeric site, Pyrenophora-caused mortality was high (34%), and effects of other pathogens and failed emergence of germinants were smaller. Cheatgrass removal negatively affected both emergence (35 vs. 25%) and spring survival (69 vs. 42%). Pyrenophora-caused seed mortality increased with inoculum augmentation for both species (22 vs. 47% overall), but emergence was negatively impacted only for P. spicata (20 vs. 34%). At the mesic site, Pyrenophora-caused mortality was low (6%). Cheatgrass removal doubled emergence (26 vs. 14%). Seed mortality increased significantly with inoculum augmentation for P. spicata (12 vs. 5%) but not E. elymoides, while emergence was not significantly affected in either species. A large fraction of seeds produced germinants that failed to emerge (37%), while another large fraction (35%) was killed by other pathogens. We conclude that facilitation by cheatgrass at the xeric site but interference at the mesic site was probably mediated through litter effects that could be ameliorative or suppressive. Apparent competition between cheatgrass and native grasses could occur through Pyrenophora, especially in a xeric environment, but effects were weak or absent at emergence. This was probably because Pyrenophora attacks the same slow-germinating fraction that is subject to pre-emergence mortality from

  8. Hydraulic performance of grass swales for managing highway runoff.

    PubMed

    Davis, Allen P; Stagge, James H; Jamil, Eliea; Kim, Hunho

    2012-12-15

    The hydraulic performance of grass swales as a highway stormwater control measure was evaluated in a field-scale study adjacent to a Maryland highway. Two common swale design alternatives, pretreatment grass filter strips and vegetated check dams, were compared during 52 storm events over 4.5 years. Swale performance is described via three regimes, dependent on the relative size of the rainfall event. Overall, half of the events were small enough that the entire flow was stored, infiltrated, and evapotranspirated by the swales, resulting in no net swale discharge. Swales significantly reduced total volume and flow magnitudes generally during events with rainfall less than 3 cm. While the majority of improvement can be attributed to the swales, inclusion of check dams increases swale effectiveness. Pretreatment grass filter strips produced mixed effects. The swales demonstrated essentially no volumetric reduction during large storm events, functioning instead as conveyance, and smoothing fluctuations in flow.

  9. Insect herbivory on C3 and C4 grasses.

    PubMed

    Boutton, Thomas W; Cameron, Guy N; Smith, Bruce N

    1978-01-01

    This study tested the hypothesis that grasses with the C4 photosynthetic pathway are avoided as a food source by insect herbivores in natural communities. Insects were sampled from ten pairs of C3-C4 grasses and their distributions analyzed by paired comparisons tests. Results showed no statistically significant differences in herbivore utilization of C3-C4 species. However, there was a trend towards heavier utilization of C3 species when means for both plant groups were compared. In particular, Homoptera and Diptera showed heavier usage of C3 plants. Significant correlations between insect abundances and plant protein levels suggest that herbivores respond to the higher protein content of C3 grasses. δ(13)C values for six of the most common grasshopper species in the study area indicated that three species fed on C3 plants, two species fed on C4 plants, and one species consumed a mixture of C3 and C4 tissue.

  10. Case report of chondroma in a grass carp (Ctenopharyngodon idella)

    PubMed Central

    Mesbah, Mehrzad; Rezaie, Annahita; Tulaby Dezfuly, Zahra

    2016-01-01

    The grass carp (Ctenopharyngodon idella) is a herbivorous, freshwater fish species of the family Cyprinidae, and the only species of the genus Ctenopharyngodon. Neoplasms in fishes are generally less aggressive than neoplasms in mammals and are most commonly discrete, focal and benign neoplasms. A 3-year-old grass carp with a big mass on the vertebrae was referred to the clinic. According to the owner’s statements, the fish had no signs of lethargy, ataxia and abnormal behaviors. The size of the mass was 7 × 6 × 6 cm. It cut hardly with audible sounds. The consistency of the mass was as hard as a cartilage. Microscopic examination revealed numerous irregular crests of hyaline cartilage beneath the skin. According to histopathologic characteristics, chondroma on the vertebrae of grass carp was diagnosed. PMID:27482364

  11. Keep on growing: building and patterning leaves in the grasses.

    PubMed

    Lewis, Michael W; Hake, Sarah

    2016-02-01

    Monocot leaves have unique features that arise early in their development. Maturing leaves protectively enclose younger leaves and the meristem, the pool of founder cells from which a leaf emerges. Through the maturation process, proximal sheath and distal blade tissues differentiate and are separated by the ligule and auricle structures. Here we review current research focusing on the contribution of gene regulatory factors and phytohormones on the patterning and differentiation of monocot leaves primarily focusing on research in the grasses (Poaceae). The 10000 members of the grasses include the true grain cereals (wheat, rice, maize, etc.), biofuel crops such as sugarcane, pasture grasses, and bamboo. They are the most studied of the monocots due to their tremendous agricultural and agronomic importance.

  12. St. Augustine grass germplasm resistant to Blissus insularis (Hemiptera: Blissidae).

    PubMed

    Youngs, Katharine M; Milla-Lewis, Susana R; Brandenburg, Rick L; Cardoza, Yasmin J

    2014-08-01

    St. Augustine grass (Stenotaphrum secundatum (Walter) Kuntze) is an economically important turfgrass in the southeastern United States. However, this turf species is prone to southern chinch bug, Blissus insularis Barber (Heteroptera: Blissidae) outbreaks. This insect is the most destructive pest of St. Augustine grass wherever this turf grass is grown. Host plant resistance has historically been an effective management tool for southern chinch bug. Since 1973, the 'Floratam' St. Augustine grass cultivar effectively controlled southern chinch bug in the southeast. However, southern chinch bug populations from Florida and Texas have now circumvented this resistance, through mechanisms still unknown. Therefore, identifying and deploying new cultivars with resistance to the southern chinch bug is imperative to combat this pest in an economically and environmentally sustainable manner. Currently, the number of cultivars with resistance against southern chinch bug is limited, and their efficacy, climatic adaptability, and aesthetic characters are variable. Hence, the main focus of this study is the identification of alternative sources of resistance to southern chinch bugs in previously uncharacterized St. Augustine grass plant introductions (PIs) and its closely related, crossbreeding species, Pembagrass (Stenotaphrum dimidiatum (L.) Brongniart). The PIs exhibited a wide range of responses to southern chinch bug feeding, as indicated by damage ratings. Damage ratings for seven PIs grouped with our resistant reference cultivars. Moreover, nine PIs exhibited antibiosis, based on poor development of southern chinch bug neonates, when compared with our susceptible reference cultivars. Altogether our study has produced strong support to indicate these materials are good candidates for future southern chinch bug resistance breeding in St. Augustine grass.

  13. Variations of Roughness Coefficients with Flow Depth of Grassed Swale

    NASA Astrophysics Data System (ADS)

    Mustaffa, N.; Ahmad, N. A.; Razi, M. A. M.

    2016-07-01

    Grassed swales are the best management practice (BMP), which has been widely used to reduce the peak flow, reduce water pollution through vegetated filtration, and improve the groundwater recharge. Universiti Tun Hussein Onn Malaysia (UTHM) is using the approach of grassed swales recommended by the Department of Irrigation and Drainage Malaysia (DID) for reducing the risk of flooding and controlling the water pollution. This paper investigates the variations of roughness coefficients with the flow depth of grassed swales in the campus of UTHM. Fieldwork was carried out on the grassed swale to collect the hydraulic data, which including the levelling work, measuring the flow depth and flow velocity of the swale. The flow depth of swale was taken at three points divided along the width of swale and the flow velocity is captured three times at each of the point. The variations of roughness coefficients of grassed swales are presented in Manning's equation, and the results reveal that the n value increases with the increasing of flow depth. Manning's coefficient value found in this study is in the range of 0.110 to 0.756, which are higher than the value proposed by the Urban Stormwater Management Manual for Malaysia (MSMA). The relationships of flow depth and velocity at each section of the swale are portrayed in graphs, which show that the velocity increases with the decreasing of flow depth. The outcomes of this study can be concluded that the variation of Manning's coefficient value is influenced by the swale profile, flow depth, flow velocity, and as well as the vegetation used in the grassed swale concerned.

  14. Endophytic Fusarium spp. from Roots of Lawn Grass (Axonopus compressus)

    PubMed Central

    Zakaria, Latiffah; Ning, Chua Harn

    2013-01-01

    Fungal endophytes are found inside host plants but do not produce any noticeable disease symptoms in their host. In the present study, endophytic Fusarium species were isolated from roots of lawn grass (Axonopus compressus). A total of 51 isolates were recovered from 100 root segments. Two Fusarium species, F. oxysporum (53%) and F. solani (47%), were identified based on macroconidia and conidiogenous cell morphology. The detection of endophytic F. oxysporum and F. solani in the roots of lawn grass contributes to the knowledge of both the distribution of the two Fusarium species and the importance of roots as endophytic niches for Fusarium species. PMID:24575251

  15. Soil C storage and greenhouse gas emission perennial grasses managed for bio energy feedstock

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial grasses like switchgrass or big bluestem when managed as bioenergy feedstock require nitrogenous inputs. Nitrogen fertilizer frequently cause nitrous oxide emission. Therefore, managing grasses as feedstock may reduce the greenhouse gas (GHG) mitigation potential expected from perennial. ...

  16. Cell wall composition throughout development for the model grass Brachypodium distachyon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperate perennial grasses are important worldwide as livestock nutritive energy sources and potential feedstock for lignocellulosic biofuel production. The annual temperate grass, Brachypodium distanchyon, has been championed as a useful model system to facilitate biological research in agricultur...

  17. Penetrating palpebral grass awn in a dog: Unusual case of a penetrating grass awn in an eyelid.

    PubMed

    Marchegiani, Andrea; Fruganti, Alessandro; Cerquetella, Matteo; Cassarani, Maria Paola; Laus, Fulvio; Spaterna, Andrea

    2017-03-01

    An unusual case of a penetrating grass awn in an eyelid of a dog is reported. A 6-month-old mixed breed dog was referred to the Ophthalmology Unit of the Veterinary Teaching Hospital of Camerino University for anorexia, lethargy, left monolateral ocular swelling and pain to the left eye, present from 1 month. Ophthalmic examination of the left eye showed copious and purulent discharge, and ultrasonography revealed the presence of an abscess containing a grass foreign body. The grass awn was surgically removed. Three days after surgery, the dog showed a marked improvement, with a total resolution obtained in 7 days. To the authors' knowledge, penetrating foreign bodies such as the one of this paper have never been described before in literature.

  18. Leaf Photosynthesis and Plant Competitive Success in a Mixed-grass Prairie: With Reference to Exotic Grasses Invasion

    SciTech Connect

    Dong, Dr. Xuejun; Patton, J.; Gu, Lianhong; Wang, J.; Patton, B.

    2014-11-26

    The widespread invasion of exotic cool-season grasses in mixed-grass rangeland is diminishing the hope of bringing back the natural native plant communities. However, ecophysiological mechanisms explaining the relative competitiveness of these invasive grasses over the native species generally are lacking. In this study, we used experimental data collected in south-central North Dakota, USA to address this issue. Photosynthetic potential was obtained from the net assimilation (A) vs. internal CO2 (Ci) response curves from plants grown in a greenhouse. Plant success was defined as the average frequency measured over 25 years (1988 to 2012) on overflow range sites across five levels of grazing intensity. In addition, estimated leaf area index of individual species under field conditions was used to indicate plant success. The correlation between photosynthetic potential based on A/Ci curves and plant frequency was negative. The correlation between leaf photosynthesis and plant success (defined as leaf area within a unit land area) was also negative, although statistically weak. These results suggest that the two cool-season grasses, Poa pratensis and Bromus inermis, do not rely on superior leaf-level photosynthesis for competitive success. Instead, some other traits, such as early and late-season growth, may be more important for them to gain dominance in the mixed-grass prairie. We propose that the negative photosynthesis-frequency relation as observed in this study results from a strong competition for limited soil nutrients in the mixed-grass prairie. In conclusion, it has implications for the stability and productivity of the grassland under various human disruptions influencing the soil nutrient status.

  19. Leaf Photosynthesis and Plant Competitive Success in a Mixed-grass Prairie: With Reference to Exotic Grasses Invasion

    DOE PAGES

    Dong, Dr. Xuejun; Patton, J.; Gu, Lianhong; ...

    2014-11-26

    The widespread invasion of exotic cool-season grasses in mixed-grass rangeland is diminishing the hope of bringing back the natural native plant communities. However, ecophysiological mechanisms explaining the relative competitiveness of these invasive grasses over the native species generally are lacking. In this study, we used experimental data collected in south-central North Dakota, USA to address this issue. Photosynthetic potential was obtained from the net assimilation (A) vs. internal CO2 (Ci) response curves from plants grown in a greenhouse. Plant success was defined as the average frequency measured over 25 years (1988 to 2012) on overflow range sites across five levelsmore » of grazing intensity. In addition, estimated leaf area index of individual species under field conditions was used to indicate plant success. The correlation between photosynthetic potential based on A/Ci curves and plant frequency was negative. The correlation between leaf photosynthesis and plant success (defined as leaf area within a unit land area) was also negative, although statistically weak. These results suggest that the two cool-season grasses, Poa pratensis and Bromus inermis, do not rely on superior leaf-level photosynthesis for competitive success. Instead, some other traits, such as early and late-season growth, may be more important for them to gain dominance in the mixed-grass prairie. We propose that the negative photosynthesis-frequency relation as observed in this study results from a strong competition for limited soil nutrients in the mixed-grass prairie. In conclusion, it has implications for the stability and productivity of the grassland under various human disruptions influencing the soil nutrient status.« less

  20. Rhizosphere priming effects in two contrasting soils

    NASA Astrophysics Data System (ADS)

    Lloyd, Davidson; Kirk, Guy; Ritz, Karl

    2015-04-01

    Inputs of fresh plant-derived carbon may stimulate the turnover of existing soil organic matter by so-called priming effects. Priming may occur directly, as a result of nutrient 'mining' by existing microbial communities, or indirectly via population adjustments. However the mechanisms are poorly understood. We planted C4 Kikuyu grass (Pennisetum clandestinum) in pots with two contrasting C3 soils (clayey, fertile TB and sandy, acid SH), and followed the soil CO2 efflux and its δ13C. The extent of C deposition in the rhizosphere was altered by intermittently clipping the grass in half the pots; there were also unplanted controls. At intervals, pots were destructively sampled for root and shoot biomass. Total soil CO2 efflux was measured using a gas-tight PVC chamber fitted over bare soil, and connected to an infra-red gas analyser; the δ13C of efflux was measured in air sub-samples withdrawn by syringe. The extent of priming was inferred from the δ13C of efflux and the δ13C of the plant and soil end-members. In unclipped treatments, in both soils, increased total soil respiration and rhizosphere priming effects (RPE) were apparent compared to the unplanted controls. The TB soil had greater RPE overall. The total respiration in clipped TB soil was significantly greater than in the unplanted controls, but in the clipped SH soil it was not significantly different from the controls. Clipping affected plant C partitioning with greater allocation to shoot regrowth from about 4 weeks after planting. Total plant biomass decreased in the order TB unclipped > SH unclipped >TB clipped > SH clipped. The results are consistent with priming driven by microbial activation stimulated by rhizodeposits and by nitrogen demand from the growing plants under N limited conditions. Our data suggest that photosynthesis drives RPE and soil differences may alter the rate and intensity of RPE but not the direction.

  1. From the Lab Bench: Differences in annual and perennial grasses in meeting cattle production goals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A column was written that provided the advantages and disadvantages of annual warm- and cool-season grasses. Warm-season annual grasses can increase the supply of forage during the summer slump in cool-season perennial grass growth. Utilization of toxic endophyte-infected tall fescue pastures can ...

  2. Grass hosts of cereal aphids (Hemiptera: Aphididae) between wheat-cropping cycles in South Dakota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several grasses may serve as alternative hosts for cereal aphids during the interim between small-grain crops in South Dakota, but field studies to determine which grasses are important have not been undertaken. We sampled annual and perennial grasses for cereal aphids in 18 counties in South Dakot...

  3. Development of eastern gamagrass into the desirable grass it is today

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eastern gamagrass is a robust, perennial warm-season bunch-grass native from the Texas panhandle to the east coast. It has long been recognized as a highly productive and palatable forage grass that begins growing earlier in the spring than most warm-season grasses and produces good growth followin...

  4. 26 CFR 56.4911-3 - Expenditures for direct and/or grass roots lobbying communications.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 17 2014-04-01 2014-04-01 false Expenditures for direct and/or grass roots....4911-3 Expenditures for direct and/or grass roots lobbying communications. (a) Definition of term... lobbying communication's costs is a direct lobbying expenditure, what portion is a grass roots...

  5. 26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 17 2012-04-01 2012-04-01 false Records of lobbying and grass roots... lobbying and grass roots expenditures. (a) Records of lobbying expenditures. An electing public charity... organization must keep a record include the following: (1) Expenditures for grass roots lobbying, as...

  6. 26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Records of lobbying and grass roots... lobbying and grass roots expenditures. (a) Records of lobbying expenditures. An electing public charity... organization must keep a record include the following: (1) Expenditures for grass roots lobbying, as...

  7. 26 CFR 56.4911-3 - Expenditures for direct and/or grass roots lobbying communications.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Expenditures for direct and/or grass roots....4911-3 Expenditures for direct and/or grass roots lobbying communications. (a) Definition of term... lobbying communication's costs is a direct lobbying expenditure, what portion is a grass roots...

  8. 26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 17 2013-04-01 2013-04-01 false Records of lobbying and grass roots... lobbying and grass roots expenditures. (a) Records of lobbying expenditures. An electing public charity... organization must keep a record include the following: (1) Expenditures for grass roots lobbying, as...

  9. 26 CFR 56.4911-3 - Expenditures for direct and/or grass roots lobbying communications.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 17 2013-04-01 2013-04-01 false Expenditures for direct and/or grass roots....4911-3 Expenditures for direct and/or grass roots lobbying communications. (a) Definition of term... lobbying communication's costs is a direct lobbying expenditure, what portion is a grass roots...

  10. 26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 17 2014-04-01 2014-04-01 false Records of lobbying and grass roots... lobbying and grass roots expenditures. (a) Records of lobbying expenditures. An electing public charity... organization must keep a record include the following: (1) Expenditures for grass roots lobbying, as...

  11. Risk of exotic annual grass-fire cycle in Goose Creek milkvetch habitat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is a concern that habitats surrounding Goose Creek milkvetch populations are at risk of exotic annual grass invasion leading to an exotic annual grass-fire cycle. We sampled plant community and site characteristics to evaluate the risk of these habitats developing an exotic annual grass-fire ...

  12. Leaf Vascular Systems in C3 and C4 Grasses: A Two-dimensional Analysis

    PubMed Central

    UENO, OSAMU; KAWANO, YUKIKO; WAKAYAMA, MASATAKA; TAKEDA, TOMOSHIRO

    2006-01-01

    • Background and Aims It is well documented that C4 grasses have a shorter distance between longitudinal veins in the leaves than C3 grasses. In grass leaves, however, veins with different structures and functions are differentiated: large longitudinal veins, small longitudinal veins and transverse veins. Thus, the densities of the three types of vein in leaves of C3 and C4 grasses were investigated from a two-dimensional perspective. • Methods Vein densities in cleared leaves of 15 C3 and 26 C4 grasses representing different taxonomic groups and photosynthetic subtypes were analysed. • Key Results The C4 grasses had denser transverse veins and denser small longitudinal veins than the C3 grasses (1·9 and 2·1 times in interveinal distance), but there was no significant difference in large longitudinal veins. The total length of the three vein types per unit area in the C4 grasses was 2·1 times that in the C3 grasses. The ratio of transverse vein length to total vein length was 14·3 % in C3 grasses and 9·9 % in C4 grasses. The C3 grasses generally had greater species variation in the vascular distances than the C4 grasses. The bambusoid and panicoid C3 grasses tended to have a denser vascular system than the festucoid C3 grasses. There were no significant differences in the interveinal distances of the three vein types between C4 subtypes, although the NADP-malic enzyme grasses tended to have a shorter distance between small longitudinal veins than the NAD-malic enzyme and phosphoenolpyruvate carboxykinase grasses. • Conclusions It seems that C4 grasses have structurally a superior photosynthate translocation and water distribution system by developing denser networks of small longitudinal and transverse veins, while keeping a constant density of large longitudinal veins. The bambusoid and panicoid C3 grasses have a vascular system that is more similar to that in C4 grasses than to that in the festucoid C3 grasses. PMID:16464879

  13. Sediment transport in grassed swales during simulated runoff events.

    PubMed

    Bäckström, M

    2002-01-01

    Particle trapping in nine different grassed swales was measured successfully with a standardised runoff event simulation procedure. The percentage of total suspended solids removed ranged from 79 to 98%. It was found that sedimentation processes, rather than grass filtration governed the overall particle trapping efficiency. The highest particle trapping efficiency was observed in the field swales with dense, fully developed turf. A high infiltration rate was beneficial for the particle trapping and an increased swale length made it possible for smaller particles to be captured. A densely vegetated, ten metre long swale, receiving a stormwater flow of 1.0 litres per second, may capture a majority of the waterborne particles with settling velocities larger than 0.1 metres per hour. A simple model of particle trapping efficiency in grassed swales was developed and tested. It was found that mean swale residence time could be used as a design parameter for particle removal in grassed swales. The suggested exponential relationship between mean swale residence time and particle settling velocity associated with a certain trapping efficiency is so far only valid for a limited range of swale designs and residence times.

  14. New Developments in Grass Breeding for Hay and Haylage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ew forage varieties with improved traits are an essential component of best management practices for livestock agriculture. This paper discusses new varieties of several cool-season and warm-season forage grasses used for hay or haylage production and some with potential as biofuel crops....

  15. Microbial Community Diversity in Agroforestry and Grass Buffer Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agroforesty and grass buffer systems have long been promoted as a soil conservation practice that yields many environmental benefits. Previous research has described the ability of buffer systems to retain nutrients, slow water flow and soil erosion, or mitigate the potentially harmful effects of e...

  16. Exotic annual grass alters fuel amounts, continuity and moisture content

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Invasion by exotic plants are one of the most serious threats to native plant communities, biodiversity, and ecosystem functioning. Of particular concern are exotic plants that alter disturbance regimes. Exotic annual grasses are believed to increase wildfire frequency to the detriment of nativ...

  17. Diazinon and permethrin mitigation across a grass-wetland buffer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Various management practices have been proposed to help alleviate deleterious effects of pesticides associated with agricultural runoff. Vegetated buffers of different designs are often used as edge-of-field treatment practices. Two experimental systems, a control (no vegetation) and a grass-wetla...

  18. Tree-grass coexistence in the Everglades freshwater system

    NASA Astrophysics Data System (ADS)

    D'Odorico, P.; Carr, J. A.; Engel, V.

    2009-12-01

    The Everglades freshwater system exhibits a heterogeneous landscape with marshes punctuated by patches of woody vegetation (tree islands) that are typically more elevated than the surrounding marshes. Despite the diversity and spatial organization of vegetation within the tree and grass plant communities, the landscape of the Everglades exhibits the features of a two-phase system with a distinct contrast between tree islands and marshes: tree islands are more elevated, dominated by woody vegetation and relatively phosphorus rich, while marshes are grass dominated and phosphorus-poor. A parallel can be drawn between these tree-grass mosaics and the patchy vegetation typical of dryland ecosystems, particularly savannas. The coexistence of trees and grasses in patchy freshwater landscapes calls for an explanation of the underlying processes and of their susceptibility to changes in environmental conditions. We argue that the stable coexistence of sawgrass meadows and tree islands in the Everglades is the result of positive feedback mechanisms, which induce bistability in landscape dynamics. We develop a process-based zero-dimensional model to explain the coexistence of the alternative stable states of “marsh” and “tree island” in the Everglades’ freshwater landscape. This zero-dimensional model shows how alternative stable states may arise as an effect of the positive feedbacks.

  19. The Sorghum bicolor genome and the diversification of grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum, an African grass related to sugar cane and maize, is grown for food, feed, fiber and fuel. We present an initial analysis of the 730-megabase Sorghum bicolor (L.) Moench genome, placing 98% of genes in their chromosomal context using whole-genome shotgun sequence validated by genetic, phy...

  20. Brachypodium distachyon, a New Model for the Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brachypodium distachyon (Brachypodium) is a small annual grass with biological, physical and genomic attributes (e.g. rapid cycling, small stature, inbreeding, small genome, diploid accessions) suitable for use as a modern model system. In pursuit of this goal, researchers have made rapid progress i...

  1. Redesigning alfalfa for use in mixtures with forage grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A lush field consisting of a mixture of grass and legumes is the goal of many producers. Such a production system has many benefits. The most important in times of high fertilizer prices is the reduced need for nitrogen (N) because of the legume's capacity for biological nitrogen fixation. However, ...

  2. Chemotypic diversity of epichloae, fungal symbionts of grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The epichloid fungi - comprising sexual Epichlo€e species and asexual Neotyphodium species - are symbionts of cool-season grasses (subfamily Po0oideae), mostly vertically transmissible (seedborne), and well known for production of anti-herbivore alkaloids. Four classes of alkaloids are known to be p...

  3. Chemotypic diversity of epichloae, fungal symbionts of grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The epichloid fungi - comprising sexual Epichlo€e species and asexual Neotyphodium species - are symbionts of cool-season grasses (subfamily Po€oideae), mostly vertically transmissible (seedborne), and well known for production of anti-herbivore alkaloids. Four classes of alkaloids are known to be p...

  4. Infestation of grasses by eriophyoid mites (Acari: Eriophyoidea) in Turkey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the economic importance of eriophyoid mites as agricultural pests, especially of cereal crops, knowledge of the eriophyoid fauna in Turkey remains incomplete. This paper presents the results of a 3-year study on grass-infesting eriophyoid mites in Turkey. The aim of this study was to collect...

  5. Theoretical versus Grass-Roots Development of a Community Partnership

    ERIC Educational Resources Information Center

    Escandon, Socorro

    2010-01-01

    The purpose of this qualitative study was to examine Bracht, Kingbury, and Rissel's five-stage community development model as applied to a grass-roots community action group. The sample consisted of low-income, predominantly Hispanic women in a community action group in a Southwestern barrio, some of whom were experiencing domestic violence. The…

  6. Grass forages:Dynamics of digestion in the rumen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grasses have been the mainstay of the diet of grazing ruminants for thousands of years. Ruminants evolved a multi-compartment stomach to provide an environment for microbial fermentation of the complex polysaccharides that comprise the carbohydrates in plant cell walls (what we nutritionists call fi...

  7. Stomatal development in Arabidopsis and grasses: differences and commonalities.

    PubMed

    Serna, Laura

    2011-01-01

    Stomata, found on the epidermis of all terrestrial plants, consist of two specialized cells called guard cells, which surround a tiny pore. Major advances have been made in our understanding of the genetic control of stomatal development in Arabidopsis and grasses. In Arabidopsis, three basic-helix-loop-helix (bHLH) genes control the successive steps that lead to stomatal formation. SPEECHLESS (SPCH) drives the cell division that initiates the stomatal cell lineage, MUTE induces the formation of the immediate stomatal precursor cell, and FAMA causes the stomatal precursor cell to divide into the two guard cells. Recent results demonstrate that these genes share functions with their grass homologs, and that MUTE is expressed later in development than its grass counterparts. Other differences in stomatal development between these two plant groups are exemplified by the PANGLOSS1 (PAN1) gene of maize. PAN1, which encodes a leucine-rich repeat receptor-like kinase with an inactive kinase domain, promotes polarization of the subsidiary mother cell and orients its cell division plane. Because such events do not exist in Arabidopsis, it is likely that the PAN1-like genes of Arabidopsis and PAN1 are paralogs. Together, these results indicate that distinctions in the regulation of gene expression and protein function are both responsible for the divergence of stomatal development between Arabidopsis and grasses.

  8. Grass tetany in a herd of beef cows

    PubMed Central

    2005-01-01

    Abstract Five cows in a herd of 15 cattle that had just been turned out onto lush pasture after having over-wintered on poor quality hay died suddenly. Biochemical profiles collected from the cadavers revealed reduced serum levels of magnesium, urea, and beta-hydroxybutycate. Classical grass tetany (hypomagnesemia) was diagnosed on postmortem examination. PMID:16187719

  9. Co-existing grass species have distinctive arbuscular mycorrhizal communities.

    PubMed

    Vandenkoornhuyse, P; Ridgway, K P; Watson, I J; Fitter, A H; Young, J P W

    2003-11-01

    Arbuscular mycorrhizal (AM) fungi are biotrophic symbionts colonizing the majority of land plants, and are of major importance in plant nutrient supply. Their diversity is suggested to be an important determinant of plant community structure, but the influence of host-plant and environmental factors on AM fungal community in plant roots is poorly documented. Using the terminal restriction fragment length polymorphism (T-RFLP) strategy, the diversity of AM fungi was assessed in 89 roots of three grass species (Agrostis capillaris, Festuca rubra, Poa pratensis) that co-occurred in the same plots of a field experiment. The impact of different soil amendments (nitrogen, lime, nitrogen and lime) and insecticide application on AM fungal community was also studied. The level of diversity found in AM fungal communities using the T-RFLP strategy was consistent with previous studies based on clone libraries. Our results clearly confirm that an AM fungal host-plant preference exists, even between different grass species. AM communities colonizing A. capillaris were statistically different from the others (P < 0.05). Although grass species evenness changed in amended soils, AM fungal community composition in roots of a given grass species remained stable. Conversely, in plots where insecticide was applied, we found higher AM fungal diversity and, in F. rubra roots, a statistically different AM fungal community.

  10. Native warm-season grass breeding over the last century

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For 100 years, scientist from the USDA-ARS Southern Plains Range Research Station at Woodward, Oklahoma have developed and released or co-released with the USDA-NRCS and/or state agricultural experiment stations more than 75 improved cultivars of native and introduced grasses from several genera. T...

  11. Energy content of tropical grasses and legumes grown for bioenergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass samples of the tropical grasses Brachiaria brizantha (Hochst. ex A. Rich.) Staph, Brachiaria humidicola (Rendle) Schweick, Brachiaria decumbens Staph, Panicum maximum Jacq., Pennistetum alopecuroides (L.) Spreng and three species of the tropical legume Stylosanthes grown in Mato Grosso do Su...

  12. Rangeland resilience and resistance: annual and perennial grass stable states

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concept of resilience, the ability to resist a shift to an alternative vegetation state, has become an important topic in range management. To quantify the degree to which a plant community is resilient, we experimentally manipulated communities dominated by either the invasive annual grass chea...

  13. Suppression of cheatgrass by established perennial grasses: I. mechanisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cheatgrass is often considered a competitive species. In a greenhouse experiment using rhizotrons, we tested the effect of established perennial grasses (Indian ricegrass, creeping wildrye, and Snake River wheatgrass) on the growth of cheatgrass. The soil was a sandy loam A horizon of a Xeric Haploc...

  14. Grass invasion into switchgrass managed for biomass energy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass (Panicum virgatum) is a warm-season perennial grass and is the model herbaceous perennial bioenergy feedstock. Although it is indigenous to North American grasslands east of the Rocky Mountains and has been planted for forage and conservation purposes for more than 75 years, there is con...

  15. Recombinant expression and epitope mapping of grass pollen allergens.

    PubMed

    Suphioglu, C; Smith, P M; Ong, E K; Knox, R B; Singh, M B

    1996-01-01

    We have studied the expression of recombinant forms of Group 1 allergens from rye-grass and Bermuda grass pollens. Recombinant Lol p 1 expressed in bacteria bound serum IgE from allergic patients. Based on analysis of fragments of the Lol p 1 cDNA clone, the major IgE-reactive epitope has been mapped to the C-terminus. However, although SDS-denatured natural Cyn d 1 (from Bermuda grass) bound IgE, the full or partial recombinant proteins expressed in bacteria did not bind IgE. We have since expressed Cyn d 1 in the yeast Pichia pastoris and restored IgE binding. cDNA clones encoding two isoforms of Lol p 5, Lol p 5A and Lol p 5B, have been expressed in bacteria and resulting polypeptides show IgE-binding. Random fragments of these clones have been generated and when expressed as partial recombinant proteins in bacteria, allowed us to identify the major IgE-binding epitopes. The allergenic epitopes were localised towards the C-terminal half of the molecule. Although both isoforms shared similar IgE-reactive epitopes, Lol p 5B did not recognise the Lol p 5A-specific monoclonal antibody A7. At sequence level, there appear to be several amino acid differences between the antigenic epitopes of these two isoallergens. These results aid in the design of diagnostics and in grass pollen immunotherapy.

  16. Soil spectra contributions to grass canopy spectral reflectance

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.; Miller, L. D.

    1977-01-01

    The soil or background spectra contribution to grass canopy spectral reflectance for the 0.35 to 0.80 micron region was investigated using in situ collected spectral reflectance data. Regression analysis was used to estimate accurately the unexposed soil spectral reflectance and to quantify maxima and minima for soil-green vegetation reflection contrasts.

  17. Simulating diverse native C4 perennial grasses with varying rainfall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rainfall is recognized as a major factor affecting the rate of plant growth development. The impact of changes in amount and variability of rainfall on growth and production of different forage grasses needs to be quantified to determine how climate change can impact rangelands. Growth and product...

  18. Snakes in the Grass: Weaving Success for Everyone.

    ERIC Educational Resources Information Center

    Ide, Janet L.

    2000-01-01

    Describes "Snakes in the Grass," a weaving project used with special needs students. Discusses the preliminary skill-building activities used, the process for creating the students' individual snakes, and the preparation and process for how the students wove the snakes. (CMK)

  19. Evaluating perennial grass competition as a management tool

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evaluation of plant competition is highly dependent on life stage and cycle. One of the largest problems that Great Basin rangelands face is the competitive nature of the exotic and invasive annual grass, cheatgrass (Bromus tectorum). Advantages of cheatgrass are often attributed to large seed produ...

  20. Weed-suppressive bacteria to reduce annual grass weeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cheatgrass (Bromus tectorum L.), medusahead (Taeniatherum caput-medusae [L.] Nevski) and jointed goatgrass (Aegilops cylindrica L.) are exotic, annual grasses that negatively affect cereal production in cropland; reduce protein-rich forage for cattle; choke out native plants in the shrub-steppe habi...

  1. Insects traversing grass-like vertical compliant beams

    NASA Astrophysics Data System (ADS)

    Li, Chen; Fearing, Ronald; Full, Robert

    2014-03-01

    Small running animals encounter many challenging terrains. These terrains can be filled with 3D, multi-component obstacles. Here, we study cockroaches (Blaberus discoidalis) moving through grass-like vertical compliant beams during escape. We created an apparatus to control and vary geometric parameters and mechanical properties of model grass including height, width, thickness, lateral and fore-aft spacings, angle, number of layers, stiffness, and damping. We observed a suite of novel locomotor behaviors not previously described on simpler 2D ground. When model grass height was >2 × body length and lateral spacing was <0.5 × body width, the animal primarily (probability P = 50%) rolled its body onto its side to rapidly (time t = 2.1 s) maneuver through the gaps between model grass. We developed a simple energy minimization model, and found that body roll reduces the energy barriers that the animal must overcome during traversal. We hypothesized that the animal's ellipsoidal body shape facilitated traversal. To test our hypothesis, we modified body shape by adding either a rectangular or an oval plate onto its dorsal surface, and found that P dropped by an order of magnitude and t more than doubled. Upon removal of either plate, both P and t recovered. Locomotor kinematics and geometry effectively coupled to terrain properties enables negotiation of 3D, multi-component obstacles, and provides inspiration for small robots to navigate such terrain with minimal sensing and control.

  2. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  3. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  4. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  5. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass...×agrotricum, and triticale. (1) General description. (i) Germination habit: Hypogeal monocot. (ii) Food.... During germination the scutellum remains inside the seed to absorb nutrients from the endosperm...

  6. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Grass family, Poaceae (Gramineae). 201.56-5 Section 201.56-5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING... family, Poaceae (Gramineae). Kinds of seed: Bentgrasses, bluegrasses, bluestems, bromes, cereals,...

  7. Exploiting the Brachypodium Tool Box in cereal and grass research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is now a decade since Brachypodium distachyon was suggested as a model species for temperate grasses and cereals. Since then transformation protocols, large expressed sequence tag (EST) populations, tools for forward and reverse genetic screens, highly refined cytogenetic probes, germplasm coll...

  8. Bringing Scientific Inquiry Alive Using Real Grass Shrimp Research

    ERIC Educational Resources Information Center

    Aultman, Terry; Curran, Mary Carla; Partridge, Michael

    2010-01-01

    This lesson was developed for middle school students using actual research on grass shrimp ("Palaemonetes pugio") to illustrate the process of a scientific investigation. The research was conducted at Savannah State University and funded by the National Oceanic and Atmospheric Administration (NOAA) Office of Education through the Living Marine…

  9. Grass competition may benefit high density peach orchards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research demonstrated that grass competition dwarfed and reduced the yield of individual peach trees [Prunus persica (L.) Batsch] grown in narrow vegetation free areas (VFA). In this report, the area-based yield of two peach cultivars, 'Redskin' and 'Jersey Dawn' on 'Lovell', was estimated...

  10. A survey of grass-finished beef producers in Pennsylvania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To meet our goal of quantifying the environmental impacts of grass-finished beef production, data on production practices in Pennsylvania were collected at the farm level via visits and online surveys. Twenty-three responses represented a total of 1,055 animals on 2,155 acres of land. Farms were rel...

  11. Lead phytoremediation potential of Vetiver grass: a hydroponic study

    NASA Astrophysics Data System (ADS)

    Pachanoor, D. S.; Andra, S. P.; Datta, R.; Sarkar, D.

    2006-05-01

    Lead (Pb) is a toxic heavy metal that is released into the environment from a variety of sources. Sources of Pb contamination in soils can be divided into three broad categories: industrial activities, such as mining and smelting processes, agricultural activities, such as application of insecticide and municipal sewage sludge, and urban activities, such as use of Pb in gasoline, paints, and other materials. Severe Pb contamination of soils may cause a variety of environmental problems, including loss of vegetation, groundwater contamination and Pb toxicity in plants, animals and humans. The use of plants to remove toxic metals from soils (phytoremediation) is fast emerging as an acceptable strategy for cost-effective and environmentally sound remediation of contaminated soils. The objective of this study was to gain insight into the lead uptake potential and biochemical stress response mechanism in vetiver grass (Vetiveria zizanioides L.) upon exposure to Pb in contaminated soils. We investigated the effect of increasing concentrations of Pb on vetiver grass grown in a hydroponic system. Plant response to the addition of phosphate in the presence of Pb was also studied. Biochemical stress response was studied by monitoring the activities of Superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes. The results indicated that exposure to Pb in the range of 0 ppm -1200 ppm had no significant negative effects on the growth of vetiver grass. There was no considerable decrease in vetiver biomass, implying the potential of this grass for Pb phytoremediation. The translocation of Pb from the root to the shoot was up to 20%. The SOD activity was in positive correlation with Pb concentrations in the solution, but no such trend was observed with GPx. In systems containing phosphate fertilizer, lead precipitated out immediately, thereby decreasing the soluble concentration of lead, resulting in less availability of Pb to the grass.

  12. Grass Cell Walls: A Story of Cross-Linking

    PubMed Central

    Hatfield, Ronald D.; Rancour, David M.; Marita, Jane M.

    2017-01-01

    Cell wall matrices are complex composites mainly of polysaccharides, phenolics (monomers and polymers), and protein. We are beginning to understand the synthesis of these major wall components individually, but still have a poor understanding of how cell walls are assembled into complex matrices. Valuable insight has been gained by examining intact components to understand the individual elements that make up plant cell walls. Grasses are a prominent group within the plant kingdom, not only for their important roles in global agriculture, but also for the complexity of their cell walls. Ferulate incorporation into grass cell wall matrices (C3 and C4 types) leads to a cross-linked matrix that plays a prominent role in the structure and utilization of grass biomass compared to dicot species. Incorporation of p-coumarates as part of the lignin structure also adds to the complexity of grass cell walls. Feruoylation results in a wall with individual hemicellulosic polysaccharides (arabinoxylans) covalently linked to each other and to lignin. Evidence strongly suggests that ferulates not only cross-link arabinoxylans, but may be important factors in lignification of the cell wall. Therefore, the distribution of ferulates on arabinoxylans could provide a means of structuring regions of the matrix with the incorporation of lignin and have a significant impact upon localized cell wall organization. The role of other phenolics in cell wall formation such as p-coumarates (which can have concentrations higher than ferulates) remains unknown. It is possible that p-coumarates assist in the formation of lignin, especially syringyl rich lignin. The uniqueness of the grass cell wall compared to dicot sepcies may not be so much in the gross composition of the wall, but how the distinctive individual components are organized into a functional wall matrix. These features are discussed and working models are provided to illustrate how changing the organization of feruoylation and p

  13. Differentiation of plant age in grasses using remote sensing

    NASA Astrophysics Data System (ADS)

    Knox, Nichola M.; Skidmore, Andrew K.; van der Werff, Harald M. A.; Groen, Thomas A.; de Boer, Willem F.; Prins, Herbert H. T.; Kohi, Edward; Peel, Mike

    2013-10-01

    Phenological or plant age classification across a landscape allows for examination of micro-topographical effects on plant growth, improvement in the accuracy of species discrimination, and will improve our understanding of the spatial variation in plant growth. In this paper six vegetation indices used in phenological studies (including the newly proposed PhIX index) were analysed for their ability to statistically differentiate grasses of different ages in the sequence of their development. Spectra of grasses of different ages were collected from a greenhouse study. These were used to determine if NDVI, NDWI, CAI, EVI, EVI2 and the newly proposed PhIX index could sequentially discriminate grasses of different ages, and subsequently classify grasses into their respective age category. The PhIX index was defined as: (AVNIRn+log(ASWIR2n))/(AVNIRn-log(ASWIR2n)), where AVNIRn and ASWIR2n are the respective normalised areas under the continuum removed reflectance curve within the VNIR (500-800 nm) and SWIR2 (2000-2210 nm) regions. The PhIX index was found to produce the highest phenological classification accuracy (Overall Accuracy: 79%, and Kappa Accuracy: 75%) and similar to the NDVI, EVI and EVI2 indices it statistically sequentially separates out the developmental age classes. Discrimination between seedling and dormant age classes and the adult and flowering classes was problematic for most of the tested indices. Combining information from the visible near infrared (VNIR) and shortwave infrared region (SWIR) region into a single phenological index captures the phenological changes associated with plant pigments and the ligno-cellulose absorption feature, providing a robust method to discriminate the age classes of grasses. This work provides a valuable contribution into mapping spatial variation and monitoring plant growth across savanna and grassland ecosystems.

  14. Molecular cloning of the MARCH family in grass carp (Ctenopharyngodon idellus) and their response to grass carp reovirus challenge.

    PubMed

    Ou, Mi; Huang, Rong; Xiong, Lv; Luo, Lifei; Chen, Geng; Liao, Lanjie; Li, Yongming; He, Libo; Zhu, Zuoyan; Wang, Yaping

    2017-02-20

    Grass carp (Ctenopharyngodon idellus) is an economical aquaculture species in China, and the Grass Carp Reovirus (GCRV) that causes hemorrhagic disease seriously affects the grass carp cultivation industry. Substantial evidence indicates that there is an association between the membrane-associated RING-CH family of E3 ligase (MARCH) family and immune defense in mammals, while functional studies on non-mammalian MARCH proteins are limited. In order to know the characteristics of the MARCH genes in C. idellus, eight MARCH genes (MARCH1, 2, 5, 6, 7, 8, 9 and 11) were cloned and the open reading frames (ORF) were identified in grass carp. All MARCH proteins in grass carp contained an RING-CH domain, which is characteristic of the MARCH protein. The phylogenetic analysis revealed that different MARCH proteins gathered into their separate clusters. All eight members of the MARCH gene family were detected in all tissues sampled, but the relative expression level differed. In addition, the mRNA expression of all the MARCHs was regulated at different levels in the immune organs after a GCRV challenge, and they responded robustly in both the intestine and liver. The mRNA expression of MARCH8, MHC II, TfR, IL1RAP, EGR1, and DUSP1 in the intestine after GCRV infection was analyzed, and the results showed that MARCH8 could negatively regulate TfR, IL1RAP, EGR1, and DUSP1, which signaled via the MAPK or NF-κB-activation pathways that play vital roles in immunity. Our findings identified a novel gene family in C. idellus and provided novel evidence that MARCH genes are inducible and involved in the immune response. Moreover, MARCH8 might function to negatively regulate immune receptors in C. idellus. Therefore, the MARCH might play a vital role in regulating the immune response of C. idellus.

  15. Effect of surface-specific training on 20-m sprint performance on sand and grass surfaces.

    PubMed

    Binnie, Martyn J; Peeling, Peter; Pinnington, Hugh; Landers, Grant; Dawson, Brian

    2013-12-01

    This study compared the effect of an 8-week preseason conditioning program conducted on a sand (SAND) or grass (GRASS) surface on 20-m sprint performance. Twelve team-sport athletes were required to attend three 1-hour training sessions per week, including 2 surface-specific sessions (SAND, n = 6 or GRASS, n = 6) and 1 group session (conducted on grass). Throughout the training period, 20-m sprint times of all athletes were recorded on both sand and grass surfaces at the end of weeks 1, 4, and 8. Results showed a significant improvement in 20-m sand time in the SAND group only (p < 0.05), whereas 20-m grass time improved equally in both training subgroups (p < 0.05). These results suggest that surface-specificity is essential for 20-m speed improvements on sand and also that there is no detriment to grass speed gains when incorporating sand surfaces into a preseason program.

  16. First report of crown rust (Puccinia coronata var. gibberosa) on blue oat grass (Helictotrichon sempervirens) in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ornamental grasses are popular decorative plants, with sales valued at $124 million in the U. S. in 2009. One common ornamental grass is blue oat grass, Helictotrichon sempervirens (Vill.) Pilg., a large blue-green grass native to Europe. In 2011, H. sempervirens plants in a commercial nursery in ...

  17. 26 CFR 1.501(h)-3 - Lobbying or grass roots expenditures normally in excess of ceiling amount.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Lobbying or grass roots expenditures normally in... § 1.501(h)-3 Lobbying or grass roots expenditures normally in excess of ceiling amount. (a) Scope... amount or normally makes grass roots expenditures in excess of its grass roots ceiling amount....

  18. 26 CFR 1.501(h)-3 - Lobbying or grass roots expenditures normally in excess of ceiling amount.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 7 2013-04-01 2013-04-01 false Lobbying or grass roots expenditures normally in... § 1.501(h)-3 Lobbying or grass roots expenditures normally in excess of ceiling amount. (a) Scope... amount or normally makes grass roots expenditures in excess of its grass roots ceiling amount....

  19. 26 CFR 1.501(h)-3 - Lobbying or grass roots expenditures normally in excess of ceiling amount.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 7 2014-04-01 2013-04-01 true Lobbying or grass roots expenditures normally in... § 1.501(h)-3 Lobbying or grass roots expenditures normally in excess of ceiling amount. (a) Scope... amount or normally makes grass roots expenditures in excess of its grass roots ceiling amount....

  20. 26 CFR 1.501(h)-3 - Lobbying or grass roots expenditures normally in excess of ceiling amount.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 7 2012-04-01 2012-04-01 false Lobbying or grass roots expenditures normally in... § 1.501(h)-3 Lobbying or grass roots expenditures normally in excess of ceiling amount. (a) Scope... amount or normally makes grass roots expenditures in excess of its grass roots ceiling amount....

  1. 26 CFR 1.501(h)-3 - Lobbying or grass roots expenditures normally in excess of ceiling amount.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Lobbying or grass roots expenditures normally in... § 1.501(h)-3 Lobbying or grass roots expenditures normally in excess of ceiling amount. (a) Scope... amount or normally makes grass roots expenditures in excess of its grass roots ceiling amount....

  2. Grass architecture: genetic and environmental control of branching.

    PubMed

    Doust, Andrew N

    2007-02-01

    Variation in grass architecture profoundly affects light capture, competition, and reproductive success, and is responsive to environmental factors such as crowding and nutrient limitation. Recent work in both model and crop systems has uncovered many aspects of the genetic control of branching, including conservation of the MONOCULM1 and MORE AXILLARY BRANCHING/DECREASED APICAL DOMINANCE/RAMOSUS (MAX/DAD/RMS) genetic pathways among the grasses and the model dicot systems of tomato, Arabidopsis, Petunia and pea. Parallel studies on the effect of environment on branching have also begun to uncover links between environmental sensing through phytochrome pathways, and resultant changes in TEOSINTE BRANCHED1 expression, and meristem inhibition. Future work promises to integrate knowledge of phenotypic responses to environment with our understanding of the genetic and hormonal changes that underlie phenotypic change.

  3. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    PubMed

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment.

  4. Biomass potential of selected grass and legume crops

    SciTech Connect

    Cherney, J.H.; Johnson, K.D.; Volenec, J.J.; Greene, D.K. )

    1991-01-01

    Optimum management strategies for herbaceous biomass crops must be investigated concurrently with the development of cost-effective conversion processes. The objective of this paper is to evaluate the agronomic feasibility of several combinations of species and management systems for producing herbaceous biomass on sites ranging from good to marginal cropland in the Midwest region of the United States. Of the perennial grasses and legumes investigated, switchgrass showed the most potential as a biomass species. It requires minimum fertilizer inputs for high yield, is very persistent, and is effective in reducing soil erosion. Sorghum double-cropped with winter annual rye was very productive but required more inputs than switchgrass. Interseeding sorghum into perennial grasses was not a viable option, due to its great dependence on environmental variables. Plant composition varied greatly across species but was not greatly affected by environment or management treatmenst.

  5. Developmental arrest in grass shrimp embryos exposed to selected toxicants

    SciTech Connect

    Wilson, J.E.H.

    1998-12-31

    Excised embryos of the grass shrimp (Palaemonetes pugio) were exposed to single pulse concentrations of selected pollutants for 4 days. The following toxicity endpoints were monitored: rate of embryonic development, embryo mortality, and types of embryo malformation. Each endpoint exhibited concentration--response relationships which were modified by the embryonic age at which exposure commenced. Developmental retardation of up to 3 days was effected by phenol at 0.01% (V/V) and complete developmental arrest occurred at 0.05% and 0.1% (V/V). Similarly for methylene chloride, developmental retardation of 1003 days were observed at 0.1% (V/V) depending on the age of the embryos at the start of the tests. The morphological abnormalities of the embryos are described. The ecological significance of these findings and implications for the development of short-term toxicity tests using grass shrimp embryos are discussed.

  6. In situ spectral reflectance studies of tidal wetland grasses

    NASA Technical Reports Server (NTRS)

    Bartlett, D. S.; Klemas, V.

    1981-01-01

    Field measurements of wetland spectral canopy reflectance in the Landsat-MSS wavebands were correlated with biotic factors. The highest single band correlations were observed between visible (MSS Band 4: 0.5 to 0.6 micron and Band 5: 0.6 to 0.7 micron) canopy reflectance and the percentage, by weight, of live (green) vegetation in the canopies of Spartina alterniflora (salt marsh cordgrass), Spartina patens (salt meadow grass), and Distichlis spicata (spike grass). Infrared canopy reflectance displayed significant but weaker dependence on canopy parameters such as live and total biomass and canopy height. The Band 7 (0.8 to 1.1 microns)/Band 5 (0.6 to 0.7 micron) reflectance ratio was found to be highly correlated with green biomass for S. alterniflora. Highest spectral separability between the 'low marsh' S. alterniflora and the 'high marsh' Salt Hay (S. patens and D. spicata) communities in Delaware occurs during December.

  7. Group 5 allergens of timothy grass (Phl p 5) bear cross-reacting T cell epitopes with group 1 allergens of rye grass (Lol p 1).

    PubMed

    Müller, W D; Karamfilov, T; Bufe, A; Fahlbush, B; Wolf, I; Jäger, L

    1996-04-01

    Selected human T cell clones reactive with group 5 allergens of timothy grass (Phl p 5) were cross-stimulated in specific proliferation assays with group 1 allergens of rye grass (Lol p 1). Such interspecies cross-reactivities result obviously from structural motifs presented on defined Phl p 5 fragments as shown with recombinant Phl p 5 products.

  8. Cartographic Issues in the Development of a Digital GRASS Database

    DTIC Science & Technology

    1990-09-01

    Sites in Cell Format Ii 6 Map Informaion 16 7 Category Information ror Geograpic Features 16 8 Map Inrormation on Overlay 17 9 Coding Linear and Areal...outside the corridor, GRASS interprets this as defining a new direction for the line. The program saves the first point of the 22 cum nt line segment ...and the lst point that fills inside the same corrWor. The incrvcning points are corsdered unnecsary to deflne the tine segment and ae discarded. A new

  9. The potential of C4 grasses for cellulosic biofuel production

    PubMed Central

    van der Weijde, Tim; Alvim Kamei, Claire L.; Torres, Andres F.; Vermerris, Wilfred; Dolstra, Oene; Visser, Richard G. F.; Trindade, Luisa M.

    2013-01-01

    With the advent of biorefinery technologies enabling plant biomass to be processed into biofuel, many researchers set out to study and improve candidate biomass crops. Many of these candidates are C4 grasses, characterized by a high productivity and resource use efficiency. In this review the potential of five C4 grasses as lignocellulosic feedstock for biofuel production is discussed. These include three important field crops—maize, sugarcane and sorghum—and two undomesticated perennial energy grasses—miscanthus and switchgrass. Although all these grasses are high yielding, they produce different products. While miscanthus and switchgrass are exploited exclusively for lignocellulosic biomass, maize, sorghum, and sugarcane are dual-purpose crops. It is unlikely that all the prerequisites for the sustainable and economic production of biomass for a global cellulosic biofuel industry will be fulfilled by a single crop. High and stable yields of lignocellulose are required in diverse environments worldwide, to sustain a year-round production of biofuel. A high resource use efficiency is indispensable to allow cultivation with minimal inputs of nutrients and water and the exploitation of marginal soils for biomass production. Finally, the lignocellulose composition of the feedstock should be optimized to allow its efficient conversion into biofuel and other by-products. Breeding for these objectives should encompass diverse crops, to meet the demands of local biorefineries and provide adaptability to different environments. Collectively, these C4 grasses are likely to play a central role in the supply of lignocellulose for the cellulosic ethanol industry. Moreover, as these species are evolutionary closely related, advances in each of these crops will expedite improvements in the other crops. This review aims to provide an overview of their potential, prospects and research needs as lignocellulose feedstocks for the commercial production of biofuel. PMID:23653628

  10. Stable Isotope Mapping of Alaskan Grasses and Marijuana

    NASA Astrophysics Data System (ADS)

    Booth, A. L.; Wooller, M. J.

    2008-12-01

    The spatial variation of isotope signatures in organic material is a useful forensic tool, particularly when applied to the task of tracking the production and distribution of plant-derived illicit drugs. In order to identify the likely grow-locations of drugs such as marijuana from unknown locations (i.e., confiscated during trafficking), base isotope maps are needed that include measurements of plants from known grow-locations. This task is logistically challenging in remote, large regions such as Alaska. We are therefore investigating the potential of supplementing our base (marijuana) isotope maps with data derived from other plants from known locations and with greater spatial coverage in Alaska. These currently include >150 samples of modern C3 grasses (Poaceae) as well as marijuana samples (n = 18) from known grow-locations across the state. We conducted oxygen, carbon and nitrogen stable isotope analyses of marijuana and grasses (Poaceae). Poaceae samples were obtained from the University of Alaska Fairbanks (UAF) Museum of the North herbarium collection, originally collected by field botanists from around Alaska. Results indicate that the oxygen isotopic composition of these grasses range from 10‰ to 30‰, and broadly mirror the spatial pattern of water isotopes in Alaska. Our marijuana samples were confiscated around the state of Alaska and supplied to us by the UAF Police Department. δ13C, δ15N and δ18O values exhibit geographic patterns similar to the modern grasses, but carbon and nitrogen isotopes of some marijuana plants appear to be influenced by additional factors related to indoor growing conditions (supplementary CO2 sources and the application of organic fertilizer). As well as providing a potential forensic resource, our Poaceae isotope maps could serve additional value by providing resources for studying ecosystem nutrient cycling, for tracing natural ecological processes (i.e., animal migration and food web dynamics) and providing

  11. The hydrothermal system in southern Grass Valley, Pershing County, Nevada

    USGS Publications Warehouse

    Welch, Alan H.; Sorey, M.L.; Olmsted, F.H.

    1981-01-01

    Southern Grass Valley is typical extensional basin in the Basin and Range province. Leach Hot Springs, in the southern part of the valley, represents the discharge end of an active hydrothermal flow system with an estimated deep aquifer temperature of 163-173C. This report discusses results of geologic, hydrologic, geophysical and geochemical investigations used in an attempt to construct an internally consistent model of the system. (USGS)

  12. Hydrothermal system in Southern Grass Valley, Pershing County, Nevada

    SciTech Connect

    Welch, A.H.; Sorey, M.L.; Olmsted, F.H.

    1981-01-01

    Southern Grass Valley is a fairly typical extensional basin in the Basin and Range province. Leach Hot Springs, in the southern part of the valley, represents the discharge end of an active hydrothermal flow system with an estimated deep aquifer temperature of 163 to 176/sup 0/C. Results of geologic, hydrologic, geophysical and geochemical investigations are discussed in an attempt to construct an internally consistent model of the system.

  13. Evolutionary origins and ecological consequences of endophyte symbiosis with grasses.

    PubMed

    Clay, Keith; Schardl, Christopher

    2002-10-01

    Over the past 20 yr much has been learned about a unique symbiotic interaction between fungal endophytes and grasses. The fungi (Clavicipitaceae, Ascomycota) grow intercellularly and systemically in aboveground plant parts. Vertically transmitted asexual endophytes forming asymptomatic infections of cool-season grasses have been repeatedly derived from sexual species that abort host inflorescences. The phylogenetic distribution of seed-transmitted endophytes is strongly suggestive of cocladogenesis with their hosts. Molecular evidence indicates that many seed-transmitted endophytes are interspecific hybrids. Superinfection may result in hyphal fusion and parasexual recombination. Most endophytes produce one or more alkaloid classes that likely play some role in defending the host plant against pests. Hybridization may have led to the proliferation of alkaloid-production genes among asexual endophytes, favoring hybrids. The ergot alkaloid ergovaline, lolitrems, and lolines are produced by only a single sexual species, Epichloë festucae, but they are common in seed-transmitted endophytes, suggesting that E. festucae contributed genes for their synthesis. Asexual hybrids may also be favored by the counteracting of the accumulation of deleterious mutations (Muller's rachet). Endophyte infection can provide other benefits, such as enhanced drought tolerance, photosynthetic rate, and growth. Estimates of infection frequency have revealed variable levels of infection with especially high prevalence in the subfamily Pooideae. Longitudinal studies suggest that the prevalence of seed-transmitted endophytes can increase rapidly over time. In field experiments, infected tall fescue suppressed other grasses and forbs relative to uninfected fescue and supported lower consumer populations. Unlike other widespread plant/microbial symbioses based on the acquisition of mineral resources, grass/endophyte associations are based primarily on protection of the host from biotic and

  14. Facilitation or Competition? Tree Effects on Grass Biomass across a Precipitation Gradient

    PubMed Central

    Moustakas, Aristides; Kunin, William E.; Cameron, Tom C.; Sankaran, Mahesh

    2013-01-01

    Savanna ecosystems are dominated by two distinct plant life forms, grasses and trees, but the interactions between them are poorly understood. Here, we quantified the effects of isolated savanna trees on grass biomass as a function of distance from the base of the tree and tree height, across a precipitation gradient in the Kruger National Park, South Africa. Our results suggest that mean annual precipitation (MAP) mediates the nature of tree-grass interactions in these ecosystems, with the impact of trees on grass biomass shifting qualitatively between 550 and 737 mm MAP. Tree effects on grass biomass were facilitative in drier sites (MAP≤550 mm), with higher grass biomass observed beneath tree canopies than outside. In contrast, at the wettest site (MAP = 737 mm), grass biomass did not differ significantly beneath and outside tree canopies. Within this overall precipitation-driven pattern, tree height had positive effect on sub-canopy grass biomass at some sites, but these effects were weak and not consistent across the rainfall gradient. For a more synthetic understanding of tree-grass interactions in savannas, future studies should focus on isolating the different mechanisms by which trees influence grass biomass, both positively and negatively, and elucidate how their relative strengths change over broad environmental gradients. PMID:23451137

  15. Facilitation or competition? Tree effects on grass biomass across a precipitation gradient.

    PubMed

    Moustakas, Aristides; Kunin, William E; Cameron, Tom C; Sankaran, Mahesh

    2013-01-01

    Savanna ecosystems are dominated by two distinct plant life forms, grasses and trees, but the interactions between them are poorly understood. Here, we quantified the effects of isolated savanna trees on grass biomass as a function of distance from the base of the tree and tree height, across a precipitation gradient in the Kruger National Park, South Africa. Our results suggest that mean annual precipitation (MAP) mediates the nature of tree-grass interactions in these ecosystems, with the impact of trees on grass biomass shifting qualitatively between 550 and 737 mm MAP. Tree effects on grass biomass were facilitative in drier sites (MAP≤550 mm), with higher grass biomass observed beneath tree canopies than outside. In contrast, at the wettest site (MAP = 737 mm), grass biomass did not differ significantly beneath and outside tree canopies. Within this overall precipitation-driven pattern, tree height had positive effect on sub-canopy grass biomass at some sites, but these effects were weak and not consistent across the rainfall gradient. For a more synthetic understanding of tree-grass interactions in savannas, future studies should focus on isolating the different mechanisms by which trees influence grass biomass, both positively and negatively, and elucidate how their relative strengths change over broad environmental gradients.

  16. Divergent evolutionary pattern of starch biosynthetic pathway genes in grasses and dicots.

    PubMed

    Li, Chun; Li, Qi-Gang; Dunwell, Jim M; Zhang, Yuan-Ming

    2012-10-01

    Starch is the most widespread and abundant storage carbohydrate in crops and its production is critical to both crop yield and quality. In regard to the starch content in the seeds of crop plants, there is a distinct difference between grasses (Poaceae) and dicots. However, few studies have described the evolutionary pattern of genes in the starch biosynthetic pathway in these two groups of plants. In this study, therefore, an attempt was made to compare evolutionary rate, gene duplication, and selective pattern of the key genes involved in this pathway between the two groups, using five grasses and five dicots as materials. The results showed 1) distinct differences in patterns of gene duplication and loss between grasses and dicots; duplication in grasses mainly occurred before the divergence of grasses, whereas duplication mostly occurred in individual species within the dicots; there is less gene loss in grasses than in dicots, 2) a considerably higher evolutionary rate in grasses than in dicots in most gene families analyzed, and 3) evidence of a different selective pattern between grasses and dicots; positive selection may have occurred asymmetrically in grasses in some gene families, for example, ADP-glucose pyrophosphorylase small subunit. Therefore, we deduced that gene duplication contributes to, and a higher evolutionary rate is associated with, the higher starch content in grasses. In addition, two novel aspects of the evolution of the starch biosynthetic pathway were observed.

  17. Influence of competition and rainfall manipulation on the growth responses of savanna trees and grasses.

    PubMed

    February, Edmund C; Higgins, Steven I; Bond, William J; Swemmer, Louise

    2013-05-01

    In this study, we explored how rainfall manipulation influenced competitive interactions between grasses and juvenile trees (small nonreproductive trees capable of resprouting) in savanna. To do this, we manipulated rainfall amount in the field using an incomplete factorial experiment that determined the effects of rainfall reduction, no manipulation, rainfall addition, and competition between grasses and trees on grass and tree growth. As response variables, we focused on several measures of tree growth and Disc Pasture Meter settling height as an estimate of grass aboveground biomass. We conducted the study over four years, at two sites in the Kruger National Park, South Africa. Our results show that rainfall manipulation did not have substantial effects on any of the measures of tree growth we considered. However, trees at plots where grasses had been removed grew on average 15 cm more in height and 1.3-1.7 times more in basal area per year than those in plots with grasses. Grass biomass was not influenced by the presence of trees but was significantly and positively influenced by rainfall addition. These findings were not fundamentally influenced by soil type or by prevailing precipitation, suggesting applicability of our results to a wide range of savannas. Our results suggest that, in savannas, increasing rainfall serves to increase the competitive pressure exerted by grasses on trees. The implication is that recruitment into the adult tree stage from the juvenile stage is most likely in drought years when there is little competition from grass for resources and grass fuel loads are low.

  18. Ladar System Identifies Obstacles Partly Hidden by Grass

    NASA Technical Reports Server (NTRS)

    Castano, Andres

    2003-01-01

    A ladar-based system now undergoing development is intended to enable an autonomous mobile robot in an outdoor environment to avoid moving toward trees, large rocks, and other obstacles that are partly hidden by tall grass. The design of the system incorporates the assumption that the robot is capable of moving through grass and provides for discrimination between grass and obstacles on the basis of geometric properties extracted from ladar readings as described below. The system (see figure) includes a ladar system that projects a range-measuring pulsed laser beam that has a small angular width of radians and is capable of measuring distances of reflective objects from a minimum of dmin to a maximum of dmax. The system is equipped with a rotating mirror that scans the beam through a relatively wide angular range of in a horizontal plane at a suitable small height above the ground. Successive scans are performed at time intervals of seconds. During each scan, the laser beam is fired at relatively small angular intervals of radians to make range measurements, so that the total number of range measurements acquired in a scan is Ne = / .

  19. Molecular identification of the turf grass rapid blight pathogen.

    PubMed

    Craven, K D; Peterson, P D; Windham, D E; Mitchell, T K; Martin, S B

    2005-01-01

    Rapid blight is a newly described disease on turf grasses, primarily found on golf courses using suboptimal water for irrigation purposes. On the basis of shared morphological characteristics, it has been proposed that the rapid blight pathogen belongs to a genus of stramenopiles, Labyrinthula, which had been known to cause disease of marine plants only. We have collected 10 isolates from four species of turf grass in five states and sequenced portions of the SSU (18S) rDNA gene from each to provide a definitive taxonomic placement for rapid blight pathogens. We also included sequences from Labyrinthuloides yorkensis, Schizochytrium aggregatum, Aplanochytrium sp., Thraustochytrium striatum, Achlya bisexualis and several nonturf-grass isolates of Labyrinthula. We found that rapid blight isolates indeed are placed firmly within the genus Labyrinthula and that they lack detectable genetic diversity in the 18S rDNA region. We propose that the rapid blight pathogens share a recent common ancestor and might have originated from a single, infected population.

  20. Effects of gravel mulch on emergency of galleta grass seedlings

    SciTech Connect

    Winkel, V.K.; Medrano, J.C.; Stanley, C.; Walo, M.D.

    1993-02-01

    Gravel mulches show promise as effective material on the US Dept. of Energy Nevada Test Site for stabilizing erosive soils and aiding plant establishment by conserving soil water. A greenhouse study was implemented to determine the effects of gravel mulch on seedling emergence and soil water, and optimal depths of gravel for various native plant species. Greenhouse flats were sown with seeds of nine species of native grasses, forbs, and shrubs. The flats were then treated with a variety of mulch treatments including, no mulch, a 1-cm layer of soil over seeds, and 2 to 3-cm and 4 to 5-cm layers of 3 to 25-mm mixed gravel. Superimposed over these treatments were 3 irrigation treatments. Seedling density data was collected daily, and soil water was monitored daily with the gravimetric method. This study showed that under a variety of soil water conditions, a 2--3 cm gravel layer may aid emergence of galleta grass. Results from this study also demonstrated that a deeper layer of gravel (4--5 cm) prohibits emergence, probably because it acts as a physical barrier to the seedlings. Galleta grass emergence can be used as a model for how other species might respond to these seedbed and irrigation treatments, provided they have adequate germination and are exposed to similar environmental conditions.

  1. Phytoremediation potential of vetiver grass [Chrysopogon zizanioides (L.)] for tetracycline.

    PubMed

    Datta, Rupali; Das, Padmini; Smith, Stephanie; Punamiya, Pravin; Ramanathan, Dil M; Reddy, Ramana; Sarkar, Dibyendu

    2013-01-01

    The presence of veterinary and human antibiotics in soil and surface water is an emerging environmental concern. The current study was aimed at evaluating the potential of using vetiver grass as a phytoremediation agent in removing Tetracycline (TC) from aqueous media. The study determined uptake, translocation, and transformation of TC in vetiver grass as function of initial antibiotic concentrations and exposure time. Vetiver plants were grown for 60 days in a greenhouse in TC contaminated hydroponic system. Preliminary results show that complete removal of tetracycline occurred within 40 days in all TC treatments. Initial concentrations of TC had significant effect (p < 0.0001) on the kinetics of removaL Tetracycline was detected in the root as well as shoot tissues, confirming uptake and root-to-shoot translocation. Liquid-chromatography-tandem-mass-spectrometry analysis of plant tissue samples suggest presence of metabolites of TC in both root and shoot tissues of vetiver grass. The current data is encouraging and is expected to aid in developing a cost-effective, in-situ phytoremediation technique to remove TC group of antibiotics from wastewater.

  2. Phytoextraction of lead from firing range soil by Vetiver grass.

    PubMed

    Wilde, E W; Brigmon, R L; Dunn, D L; Heitkamp, M A; Dagnan, D C

    2005-12-01

    Phytoextraction techniques utilizing a sterile strain of Vetiver grass (Vetiveria zizanoides) along with soil amendments were evaluated for removing lead and other elements such as Zn, Cu, and Fe from the soil of a 50-year old active firing range at the Savannah River Site (SRS). Lead-contaminated soil (300-4500 ppm/kg) was collected, dried, placed in pots, fertilized, and used as a medium for growing transplanted Vetiver grass plants in a greenhouse. The uptake of metals by the plants was evaluated in response to various fertilization and pre-harvest treatment schemes. Baseline metal concentrations in the soil of all pots were measured prior to planting and when the plants were harvested. Plants grew better when fertilized with Osmocote fertilizer in comparison to plants fertilized with 10-10-10 (NPK) fertilizer. Application of a chelating agent, EDTA, one week prior to harvest significantly increased the amount of lead that was phytoextracted. Lead concentrations of up to 1390-1450 ppm/kg in tissue samples were detected. Maximum Pb levels were observed in root tissues. The addition of non-lethal doses of a slow-release herbicide in combination with EDTA did not appear to further enhance phytoextraction or the translocation of Pb into shoots. The study indicated that the use of Vetiver grass coupled with the use of chelating soil amendments has considerable potential for use as a remedial strategy for lead-contaminated soils such as those associated with firing ranges.

  3. EDTA enhances lead uptake and facilitates phytoremediation by vetiver grass.

    PubMed

    Gupta, Deepak Kumar; Srivastava, Alok; Singh, V P

    2008-11-01

    Vetiver grass (Vetiveria zizanioides) has strong and dense root system and is a potential phytoremediator plant since it can tolerate a wide range of climatic conditions and grow well in soils contaminated with heavy metals. Soil was artificially contaminated by lead (20 mgl(-1)) during field trials. Four concentration of EDTA (Ethylene diamine tetra acetic acid-disodium salt) solution i.e. 0, 3, 5 and 10 mmol kg(-1) were added to soil prior to harvesting, to study the influence of EDTA solution on phytostabilization by vetiver grass. Results showed that the concentration of lead in roots of vetiver is significantly increased after EDTA solution (5 mmol kg(-1)) application. However, high concentration of EDTA (10 mmol kg(-1)) does not show such significant increase. The toxicity of highly contaminating metal did not affect the growth of vetiver grass significantly but a slight decrease in parameters studied was noticed. No stress symptoms were observed in vetiver plants. Results of present study reveal that vetiver could be considered as a potential phytoremediator for lead contamninated site.

  4. Green grasses as light harvesters in dye sensitized solar cells.

    PubMed

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-25

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

  5. Perennial grass production for biofuels: Soil conversion considerations

    SciTech Connect

    McLaughlin, S.B.; Bransby, D.I.; Parrish, D.

    1994-10-01

    The increased use of renewable fuels for energy offers the United States a mechanism for significantly reducing national dependency on imported oil, reducing greenhouse gas emissions, and improving regional agricultural economies. As mandated by law, a wide range of issues have been raised regarding the net environmental impacts of implementation of these new technologies. While uncertainties regarding both positive and negative environmental influences still exist in many areas of this new technology, it is now possible to address with substantial certainty the positive aspects of perennial herbaceous energy crops on several important soil conservation issues. Past experience with forage grasses and recent research with switchgrass. A warm season perennial forage grass selected as one of the model bioenergy species, indicates that important benefits will be gained in the area of soil conservation as grasses replace energy-intensive annual row crops. These include reduced erosion, improved conservation of water and nutrients, and increased productivity of soils by the deep and vigorous rooting systems of perennial warm-season gasses.

  6. Microwave backscattering and emission model for grass canopies

    NASA Technical Reports Server (NTRS)

    Saatchi, Sasan S.; Levine, David M.; Lang, Roger H.

    1994-01-01

    Microwave radar and radiometer measurements of grasslands indicate a substantial reduction in sensor sensitivity to soil moisture in the presence of a thatch layer. When this layer is wet it masks changes in the underlying soil, making the canopy appear warm in the case of passive sensors (radiometer) and decreasing backscatter in the active case (scatterometer). A model for a grass canopy with thatch will be presented in this paper to explain this behavior and to compare with observations. The canopy model consists of three layers: grass, thatch, and the underlying soil. The grass blades are modeled by elongated elliptical discs and the thatch is modeled as a collection of disk shaped water droplets (i.e., the dry matter is neglected). The ground is homogeneous and flat. The distorted Born approximation is used to compute the radar cross section of this three layer canopy and the emissivity is computed from the radar cross section using the Peake formulation for the passive problem. Results are computed at L-band (1.4 GHz) and C-band (4.75 GHz) using canopy parameters (i.e., plant geometry, soil moisture, plant moisture, etc.) representative of Konza Prairie grasslands. The results are compared to C-band scatterometer measurements and L-band radiometer measurements at these grasslands.

  7. MicroRNA-mediated regulation of flower development in grasses.

    PubMed

    Smoczynska, Aleksandra; Szweykowska-Kulinska, Zofia

    2016-01-01

    Flower structure in grasses is very unique. There are no petals or sepals like in eudicots but instead flowers develop bract-like structures - palea and lemma. Reproductive organs are enclosed by round lodicule that not only protects reproductive organs but also plays an important role during flower opening. The first genetic model for floral organ development was proposed 25 years ago and it was based on the research on model eudicots. Since then, studies have been carried out to answer the question whether this model could be applicable in the case of monocots. Genes from all classes found in eudicots have been also identified in genomes of such monocots like rice, maize or barley. What's more, it seems that miRNA-mediated regulation of floral organ genes that was observed in the case of Arabidopsis thaliana also takes place in monocots. MiRNA172, miRNA159, miRNA171 and miRNA396 regulate expression of floral organ identity genes in barley, rice and maize, affecting various features of the flower structure, ranging from formation of lemma and palea to the development of reproductive organs. A model of floral development in grasses and its genetic regulation is not yet fully characterized. Further studies on both, the model eudicots and grasses, are needed to unravel this topic. This review provides general overview of genetic model of flower organ identity specification in monocots and it's miRNA-mediated regulation.

  8. Green grasses as light harvesters in dye sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Shanmugam, Vinoth; Manoharan, Subbaiah; Sharafali, A.; Anandan, Sambandam; Murugan, Ramaswamy

    2015-01-01

    Chlorophylls, the major pigments presented in plants are responsible for the process of photosynthesis. The working principle of dye sensitized solar cell (DSSC) is analogous to natural photosynthesis in light-harvesting and charge separation. In a similar way, natural dyes extracted from three types of grasses viz. Hierochloe Odorata (HO), Torulinium Odoratum (TO) and Dactyloctenium Aegyptium (DA) were used as light harvesters in dye sensitized solar cells (DSSCs). The UV-Vis absorption spectroscopy, Fourier transform infrared (FT-IR), and liquid chromatography-mass spectrometry (LC-MS) were used to characterize the dyes. The electron transport mechanism and internal resistance of the DSSCs were investigated by the electrochemical impedance spectroscopy (EIS). The performance of the cells fabricated with the grass extract shows comparable efficiencies with the reported natural dyes. Among the three types of grasses, the DSSC fabricated with the dye extracted from Hierochloe Odorata (HO) exhibited the maximum efficiency. LC-MS investigations indicated that the dominant pigment present in HO dye was pheophytin a (Pheo a).

  9. Enzyme pretreatment of grass lignocellulose for potential high-value co-products and an improved fermentable substrate.

    PubMed

    Anderson, William F; Peterson, Joy; Akin, Danny E; Morrison, W Herbert

    2005-01-01

    Crops such as switchgrass (Panicum virgatum L.), bermudagrass(Cynodon dactylon L.), or napiergrass (Pennisetum purpureum Schumach.)have the capacity to produce large quantities of lignocellulose for biofuel(1). To facilitate use of lignocellulosic material for ethanol, it will be necessaryto determine cost-efficient pretreatments to enhance the conversion tofermentable sugars. The lignified residual products from ethanol productioncould also provide a value-added co-product for industrial feedstocks(e.g., nutritional antioxidants, ultraviolet absorbers, resins).

  10. Small mammal use of native warm-season and non-native cool-season grass forage fields

    USGS Publications Warehouse

    Ryan L Klimstra,; Christopher E Moorman,; Converse, Sarah J.; Royle, J. Andrew; Craig A Harper,

    2015-01-01

    Recent emphasis has been put on establishing native warm-season grasses for forage production because it is thought native warm-season grasses provide higher quality wildlife habitat than do non-native cool-season grasses. However, it is not clear whether native warm-season grass fields provide better resources for small mammals than currently are available in non-native cool-season grass forage production fields. We developed a hierarchical spatially explicit capture-recapture model to compare abundance of hispid cotton rats (Sigmodon hispidus), white-footed mice (Peromyscus leucopus), and house mice (Mus musculus) among 4 hayed non-native cool-season grass fields, 4 hayed native warm-season grass fields, and 4 native warm-season grass-forb ("wildlife") fields managed for wildlife during 2 summer trapping periods in 2009 and 2010 of the western piedmont of North Carolina, USA. Cotton rat abundance estimates were greater in wildlife fields than in native warm-season grass and non-native cool-season grass fields and greater in native warm-season grass fields than in non-native cool-season grass fields. Abundances of white-footed mouse and house mouse populations were lower in wildlife fields than in native warm-season grass and non-native cool-season grass fields, but the abundances were not different between the native warm-season grass and non-native cool-season grass fields. Lack of cover following haying in non-native cool-season grass and native warm-season grass fields likely was the key factor limiting small mammal abundance, especially cotton rats, in forage fields. Retention of vegetation structure in managed forage production systems, either by alternately resting cool-season and warm-season grass forage fields or by leaving unharvested field borders, should provide refugia for small mammals during haying events.

  11. Reductions in native grass biomass associated with drought facilitates the invasion of an exotic grass into a model grassland system.

    PubMed

    Manea, Anthony; Sloane, Daniel R; Leishman, Michelle R

    2016-05-01

    The invasion success of exotic plant species is often dependent on resource availability. Aspects of climate change such as rising atmospheric CO2 concentration and extreme climatic events will directly and indirectly alter resource availability in ecological communities. Understanding how these climate change-associated changes in resource availability will interact with one another to influence the invasion success of exotic plant species is complex. The aim of the study was to assess the establishment success of an invasive exotic species in response to climate change-associated changes in resource availability (CO2 levels and soil water availability) as a result of extreme drought. We grew grassland mesocosms consisting of four co-occurring native grass species common to the Cumberland Plain Woodland of western Sydney, Australia, under ambient and elevated CO2 levels and subjected them to an extreme drought treatment. We then added seeds of a highly invasive C3 grass, Ehrharta erecta, and assessed its establishment success (biomass production and reproductive output). We found that reduced biomass production of the native grasses in response to the extreme drought treatment enhanced the establishment success of E. erecta by creating resource pulses in light and space. Surprisingly, CO2 level did not affect the establishment success of E. erecta. Our results suggest that the invasion risk of grasslands in the future may be coupled to soil water availability and the subsequent response of resident native vegetation therefore making it strongly context- dependent.

  12. Initial success of native grasses is contingent on multiple interactions among exotic grass competition, temporal priority, rainfall and site effects.

    PubMed

    Young, Truman P; Zefferman, Emily P; Vaughn, Kurt J; Fick, Stephen

    2014-12-05

    Ecological communities are increasingly being recognized as the products of contemporary drivers and historical legacies that are both biotic and abiotic. In an attempt to unravel multiple layers of ecological contingency, we manipulated (i) competition with exotic annual grasses, (ii) the timing of this competition (temporal priority in arrival/seeding times) and (iii) watering (simulated rainfall) in a restoration-style planting of native perennial grasses. In addition, we replicated this experiment simultaneously at three sites in north-central California. Native perennial grasses had 73-99 % less cover when planted with exotic annuals than when planted alone, but this reduction was greatly ameliorated by planting the natives 2 weeks prior to the exotics. In a drought year, irrigation significantly reduced benefits of early planting so that these benefits resembled those observed in a non-drought year. There were significant differences across the three sites (site effects and interactions) in (i) overall native cover, (ii) the response of natives to competition, (iii) the strength of the temporal priority effect and (iv) the degree to which supplemental watering reduced priority effects. These results reveal the strong multi-layered contingency that underlies even relatively simple communities.

  13. Initial success of native grasses is contingent on multiple interactions among exotic grass competition, temporal priority, rainfall and site effects

    PubMed Central

    Young, Truman P.; Zefferman, Emily P.; Vaughn, Kurt J.; Fick, Stephen

    2015-01-01

    Ecological communities are increasingly being recognized as the products of contemporary drivers and historical legacies that are both biotic and abiotic. In an attempt to unravel multiple layers of ecological contingency, we manipulated (i) competition with exotic annual grasses, (ii) the timing of this competition (temporal priority in arrival/seeding times) and (iii) watering (simulated rainfall) in a restoration-style planting of native perennial grasses. In addition, we replicated this experiment simultaneously at three sites in north-central California. Native perennial grasses had 73–99 % less cover when planted with exotic annuals than when planted alone, but this reduction was greatly ameliorated by planting the natives 2 weeks prior to the exotics. In a drought year, irrigation significantly reduced benefits of early planting so that these benefits resembled those observed in a non-drought year. There were significant differences across the three sites (site effects and interactions) in (i) overall native cover, (ii) the response of natives to competition, (iii) the strength of the temporal priority effect and (iv) the degree to which supplemental watering reduced priority effects. These results reveal the strong multi-layered contingency that underlies even relatively simple communities. PMID:25480888

  14. Energy, economic and environmental implications of production of grasses as biomass feedstocks

    SciTech Connect

    Downing, M.; McLaughlin, S.; Walsh, M.

    1995-08-01

    Perennial prairie grasses offer many advantages to the developing biofuels industry. High yielding varieties of native prairie grasses such as switchgrass, which combine lower levels of nutrient demand, diverse geographical growing range, high net energy yields and high soil and water conservation potential indicate that these grasses could and should supplement annual row crops such as corn in developing alternative fuels markets. Favorable net energy returns, increased soil erosion prevention, and a geographically diverse land base that can incorporate energy grasses into conventional farm practices will provide direct benefits to local and regional farm economies and lead to accelerated commercialization of conversion technologies. Displacement of row crops with perennial grasses will have major agricultural, economic, sociologic and cross-market implications. Thus, perennial grass production for biofuels offers significant economic advantages to a national energy strategy which considers both agricultural and environmental issues.

  15. Perennial grasses for energy and conservation: Evaluating some ecological agricultural, and economic issues

    SciTech Connect

    Downing, M.; Walsh, M.; McLaughlin, S.

    1995-11-01

    Perennial prairie grasses offer many advantages to the developing biofuels industry. High yielding varieties of native prairie grasses such as switchgrass, which combine lower levels of nutrient demand, diverse geographical growing range, high net energy yields and high soil and water conservation potential indicate that these grasses could and should supplement annual row crops such as corn in developing alternative fuels markets. Favorable net energy returns, increased soil erosion prevention, and a geographically diverse land base that can incorporate energy grasses into conventional farm practices will provide direct benefits to local and regional farm economies and lead to accelerated commercialization of conversion technologies. Displacement of row crops with perennial grasses will have major agricultural, economic, sociologic and cross-market implications. Thus, perennial grass production for biofuels offers significant economic advantages to a national energy strategy which considers both agricultural and environmental issues.

  16. Variation in the Activity of Some Enzymes of Photorespiratory Metabolism in C4 Grasses

    PubMed Central

    UENO, OSAMU; YOSHIMURA, YASUYUKI; SENTOKU, NAOKI

    2005-01-01

    • Background and Aims Photorespiration occurs in C4 plants, although rates are small compared with C3 plants. The amount of glycine decarboxylase in the bundle sheath (BS) varies among C4 grasses and is positively correlated with the granal index (ratio of the length of appressed thylakoid membranes to the total length of all thylakoid membranes) of the BS chloroplasts: C4 grasses with high granal index contained more glycine decarboxylase per unit leaf area than those with low granal index, probably reflecting the differences in O2 production from photosystem II and the potential photorespiratory capacity. Thus, it is hypothesized that the activities of peroxisomal enzymes involved in photorespiration are also correlated with the granal development. • Methods The granal development in BS chloroplasts was investigated and activities of the photorespiratory enzymes assayed in 28 C4 grasses and seven C3 grasses. • Key Results The NADP–malic enzyme grasses were divided into two groups: one with low granal index and the other with relatively high granal index in the BS chloroplasts. Both the NAD–malic enzyme and phosphoenolpyruvate carboxykinase grasses had high granal index in the BS chloroplasts. No statistically significant differences were found in activity of hydroxypyruvate reductase between the C3 and C4 grasses, or between the C4 subtypes. The activity of glycolate oxidase and catalase were smaller in the C4 grasses than in the C3 grasses. Among the C4 subtypes, glycolate oxidase activities were significantly smaller in the NADP–malic enzyme grasses with low granal index in the BS chloroplasts, compared with in the C4 grasses with substantial grana in the BS chloroplasts. • Conclusions There is interspecies variation in glycolate oxidase activity associated with the granal development in the BS chloroplasts and the O2 production from photosystem II, which suggests different potential photorespiration capacities among C4 grasses. PMID:16100226

  17. Preference for C4 shade grasses increases hatchling performance in the butterfly, Bicyclus safitza.

    PubMed

    Nokelainen, Ossi; Ripley, Brad S; van Bergen, Erik; Osborne, Colin P; Brakefield, Paul M

    2016-08-01

    The Miocene radiation of C4 grasses under high-temperature and low ambient CO 2 levels occurred alongside the transformation of a largely forested landscape into savanna. This inevitably changed the host plant regime of herbivores, and the simultaneous diversification of many consumer lineages, including Bicyclus butterflies in Africa, suggests that the radiations of grasses and grazers may be evolutionary linked. We examined mechanisms for this plant-herbivore interaction with the grass-feeding Bicyclus safitza in South Africa. In a controlled environment, we tested oviposition preference and hatchling performance on local grasses with C3 or C4 photosynthetic pathways that grow either in open or shaded habitats. We predicted preference for C3 plants due to a hypothesized lower processing cost and higher palatability to herbivores. In contrast, we found that females preferred C4 shade grasses rather than either C4 grasses from open habitats or C3 grasses. The oviposition preference broadly followed hatchling performance, although hatchling survival was equally good on C4 or C3 shade grasses. This finding was explained by leaf toughness; shade grasses were softer than grasses from open habitats. Field monitoring revealed a preference of adults for shaded habitats, and stable isotope analysis of field-sampled individuals confirmed their preference for C4 grasses as host plants. Our findings suggest that plant-herbivore interactions can influence the direction of selection in a grass-feeding butterfly. Based on this work, we postulate future research to test whether these interactions more generally contribute to radiations in herbivorous insects via expansions into new, unexploited ecological niches.

  18. Studies on soil to grass transfer factor (Fv) and grass to milk transfer coefficient (Fm) for cesium in Kaiga region.

    PubMed

    Karunakara, N; Ujwal, P; Yashodhara, I; Rao, Chetan; Sudeep Kumara, K; Dileep, B N; Ravi, P M

    2013-10-01

    Detailed studies were carried out to establish site-specific soil to grass transfer factors (Fv) and grass to cow milk transfer coefficients (Fm) for radioactive cesium ((137)Cs) and stable cesium (Cs) for Kaiga region, where a nuclear power station has been in operation for more than 10 years. The study included adopted cows, cows of local farmers, and cows from the dairy farm. A grass field was developed specifically for the study and 2 local breed cows were adopted and allowed to graze in this grass field. The soil and grass samples were collected regularly from this field and analyzed for the concentrations of (137)Cs and stable Cs to evaluate the soil to grass Fv values. The milk samples from the adopted cows were analyzed for the (137)Cs and stable Cs concentrations to evaluate Fm values. For comparison, studies were also carried out in dominant grazing areas in different villages around the nuclear power plant and the cows of local farmers which graze in these areas were identified and milk samples were collected and analyzed regularly. The geometric mean values of Fv were found to be 1.1 × 10(-1) and 1.8 × 10(-1) for (137)Cs and stable Cs, respectively. The Fm of (137)Cs had geometric mean values of 1.9 × 10(-2) d L(-1) and 4.6 × 10(-2) d L(-1), respectively, for adopted Cows 1 and 2; 1.7 × 10(-2) d L(-1) for the cows of local farmers, and 4.0 × 10(-3) d L(-1) for the dairy farm cows. The geometric mean values of Fm for stable Cs were similar to those of (137)Cs. The Fm value for the dairy farm cows was an order of magnitude lower than those for local breed cows. The Fm values observed for the local breed cows were also an order of magnitude higher when compared to the many values reported in the literature and in the IAEA publication. Possible reasons for this higher Fm values were identified. The correlation between Fv and Fm values for (137)Cs and stable Cs and their dependence on the potassium content ((40)K and stable K) in

  19. Acute toxic effects of endosulfan sulfate on three life stages of grass shrimp, Palaemonetes pugio.

    PubMed

    Key, Peter B; Chung, Katy W; Venturella, John J; Shaddrick, Brian; Fulton, Michael H

    2010-01-01

    In this study, the toxicity of endosulfan sulfate, the primary degradation product of the insecticide endosulfan, was determined in three life stages of the grass shrimp (Palaemonetes pugio). After 96 h exposure to endosulfan sulfate, the grass shrimp adult LC50 was 0.86 microg/L (95% CI 0.56-1.31), the grass shrimp larvae LC50 was 1.64 microg/L (95% CI 1.09-2.47) and the grass shrimp embryo LC50 was 45.85 microg/L (95% CI 23.72-88.61 microg/L). This was compared to the previously published grass shrimp 96-h LC50s for endosulfan. The toxicity of the two compounds was similar for the grass shrimp life stages with adults more sensitive than larvae and embryos. The presence of sediment in 24h endosulfan sulfate-exposures raised LC50s for both adult and larval grass shrimp but not significantly. The USEPA expected environmental concentrations (EEC) for total endosulfan and endosulfan sulfate and the calculations of risk quotients (RQ) based on the more sensitive adult grass shrimp 96-h LC50 clearly show that environmental concentrations equal to acute EECs would prove detrimental to grass shrimp or other similarly sensitive aquatic organisms. These results indicate that given the persistence and toxicity of endosulfan sulfate, future risk assessments should consider the toxicity potential of the parent compound as well as this degradation product.

  20. Anaerobic co-digestion of sewage sludge with shredded grass from public green spaces.

    PubMed

    Hidaka, Taira; Arai, Sayuri; Okamoto, Seiichiro; Uchida, Tsutomu

    2013-02-01

    Adding greenery from public spaces to the co-digestion process with sewage sludge was evaluated by shredding experiments and laboratory-scale batch and continuous mesophilic anaerobic fermentation experiments. The ratio of the shredded grass with 20mm or less in length by a commercially available shredder was 93%. The methane production was around 0.2NL/gVS-grass in the batch experiment. The continuous experiment fed with sewage sludge and shredded grass was stably operated for 81days. The average methane production was 0.09NL/gVS-grass when the TS ratio of the sewage sludge and the grass was 10:1. This value was smaller than those of other reports using grass silage, but the grass species in this study were not managed, and the collected grass was just shredded and not ensiled before feeding to the reactor for simple operation. The addition of grass to a digester can improve the carbon/nitrogen ratio, methane production and dewaterability.

  1. Canopy growth and density of Wyoming big sagebrush sown with cool-season perennial grasses

    SciTech Connect

    Hild, A.L.; Schuman, G.E.; Vicklund, L.E.; Williams, M.I.

    2006-07-15

    Post-mining revegetation efforts often require grass seeding and mulch applications to stabilize the soils at the same time as shrub seeding, creating intraspecific competition between seeded shrubs and grasses that is not well understood. In 1999, we initiated a study at the Belle Ayr Coal Mine near Gillette, Wyoming, to evaluate the influence of grass competition on establishment and growth of Wyoming big sagebrush. Combinations of three sagebrush seeding rates (1, 2, and 4 kg pls ha{sup -1}) and seven cool-season perennial grass mixture seeding rates (0, 2, 4, 6, 8, 10, and 14 kg pls ha{sup -1}) were seeded during winter 1998-1999. Shrub density and grass cover were assessed from 1999 to 2004. We monitored sagebrush canopy size in 2001, 2002, and 2004. All sagebrush seeding rates provided shrub densities (>=) 1 shrub m {sup -1} after six growing seasons. Grass production (>=) 75 g m{sup -2} was achieved by seeding grasses at 6 to 8 kg pls ha{sup -1}). Canopy growth of individual sagebrush plants was least in the heaviest grass seeding rate. Reduced grass seeding rates can aid in achieving Wyoming big sagebrush density standards and enhance shrub canopy growth.

  2. Culturing and direct PCR suggest prevalent host generalism among diverse fungal endophytes of tropical forest grasses.

    PubMed

    Higgins, K Lindsay; Coley, Phyllis D; Kursar, Thomas A; Arnold, A Elizabeth

    2011-01-01

    Most studies examining endophytic fungi associated with grasses (Poaceae) have focused on agronomically important species in managed ecosystems or on wild grasses in subtropical, temperate and boreal grasslands. However grasses first arose in tropical forests, where they remain a significant and diverse component of understory and forest-edge communities. To provide a broader context for understanding grass-endophyte associations we characterized fungal endophyte communities inhabiting foliage of 11 species of phylogenetically diverse C(3) grasses in the understory of a lowland tropical forest at Barro Colorado Island, Panama. Our sample included members of early-arising subfamilies of Poaceae that are endemic to forests, as well as more recently arising subfamilies that transitioned to open environments. Isolation on culture media and direct PCR and cloning revealed that these grasses harbor species-rich and phylogenetically diverse communities that lack the endophytic Clavicipitaceae known from diverse woodland and pasture grasses in the temperate zone. Both the incidence and diversity of endophytes was consistent among grass species regardless of subfamily, clade affiliation or ancestral habitat use. Genotype and phylogenetic analyses suggest that these endophytic fungi are predominantly host generalists, shared not only among distinctive lineages of Poaceae but also with non-grass plants at the same site.

  3. Advances in Research on Epichloë endophytes in Chinese Native Grasses

    PubMed Central

    Song, Hui; Nan, Zhibiao; Song, Qiuyan; Xia, Chao; Li, Xiuzhang; Yao, Xiang; Xu, Wenbo; Kuang, Yu; Tian, Pei; Zhang, Qingping

    2016-01-01

    Epichloë fungal endophytes are broadly found in cool-season grasses. The symbiosis between these grasses and Epichloë may improve the abiotic and biotic resistance of the grass plant, but some Epichloë species produce alkaloids that are toxic for livestock. Therefore, it is important to understand the characteristics of the grass-Epichloë s symbiosis so that the beneficial aspects can be preserved and the toxic effects to livestock can be avoided. Since the 1990s, Chinese researchers have conducted a series of studies on grass-Epichloë symbiosis. In this review, we describe the current state of Epichloë endophyte research in Chinese native grasses. We found that more than 77 species of native grasses in China are associated with Epichloë endophytes. In addition, we review the effects of various Epichloë species on native grass responses to abiotic and biotic stress, phylogeny, and alkaloid production. We provide an overview of the study of Epichloë species on native grasses in China and directions for future research. PMID:27656171

  4. Advances in Research on Epichloë endophytes in Chinese Native Grasses.

    PubMed

    Song, Hui; Nan, Zhibiao; Song, Qiuyan; Xia, Chao; Li, Xiuzhang; Yao, Xiang; Xu, Wenbo; Kuang, Yu; Tian, Pei; Zhang, Qingping

    2016-01-01

    Epichloë fungal endophytes are broadly found in cool-season grasses. The symbiosis between these grasses and Epichloë may improve the abiotic and biotic resistance of the grass plant, but some Epichloë species produce alkaloids that are toxic for livestock. Therefore, it is important to understand the characteristics of the grass-Epichloë s symbiosis so that the beneficial aspects can be preserved and the toxic effects to livestock can be avoided. Since the 1990s, Chinese researchers have conducted a series of studies on grass-Epichloë symbiosis. In this review, we describe the current state of Epichloë endophyte research in Chinese native grasses. We found that more than 77 species of native grasses in China are associated with Epichloë endophytes. In addition, we review the effects of various Epichloë species on native grass responses to abiotic and biotic stress, phylogeny, and alkaloid production. We provide an overview of the study of Epichloë species on native grasses in China and directions for future research.

  5. The use of food waste-based diets and Napier grass to culture grass carp: growth performance and contaminants contained in cultured fish.

    PubMed

    Cheng, Zhang; Mo, Wing-Yin; Nie, Xiang-Ping; Li, Kai-Bing; Choi, Wai-Ming; Man, Yu-Bon; Wong, Ming-Hung

    2016-04-01

    The present study used commercial feeds, food waste feeds, Napier grass, and mixed feeds (food waste feed to Napier grass ratio, 1:10) to feed grass carp (Ctenopharyngodon idellus). The results indicated that grass carp fed with food waste feeds and mix feeds achieved growth performance (based on specific growth rate and feed conversion ratio) that was similar to commercial feeds (p > 0.05). Concentrations of metalloid/metals in food waste feeds and polycyclic aromatic hydrocarbons (PAHs) in Napier grass were relatively higher than other types of fish feeds (p < 0.05). However, most of the metalloid/metals and PAH levels in fish fed with four types of fish feeds were not significantly different (p > 0.05). These findings show that food waste feeds are suitable for using in the production of fish feed and Napier grass can be served as supplemental feeds for grass carp, and hence reducing the production cost.

  6. Modeled hydraulic redistribution in tree-grass, CAM-grass, and tree-CAM associations: the implications of crassulacean acid metabolism (CAM).

    PubMed

    Yu, Kailiang; Foster, Adrianna

    2016-04-01

    Past studies have largely focused on hydraulic redistribution (HR) in trees, shrubs, and grasses, and recognized its role in interspecies interactions. HR in plants that conduct crassulacean acid metabolism (CAM), however, remains poorly investigated, as does the effect of HR on transpiration in different vegetation associations (i.e., tree-grass, CAM-grass, and tree-CAM associations). We have developed a mechanistic model to investigate the net direction and magnitude of HR at the patch scale for tree-grass, CAM-grass, and tree-CAM associations at the growing season to yearly timescale. The modeling results show that deep-rooted CAM plants in CAM-grass associations could perform hydraulic lift at a higher rate than trees in tree-grass associations in a relatively wet environment, as explained by a significant increase in grass transpiration rate in the shallow soil layer, balancing a lower transpiration rate by CAM plants. By comparison, trees in tree-CAM associations may perform hydraulic descent at a higher rate than those in tree-grass associations in a dry environment. Model simulations also show that hydraulic lift increases the transpiration of shallow-rooted plants, while hydraulic descent increases that of deep-rooted plants. CAM plants transpire during the night and thus perform HR during the day. Based on these model simulations, we suggest that the ability of CAM plants to perform HR at a higher rate may have different effects on the surrounding plant community than those of plants with C3 or C4 photosynthetic pathways (i.e., diurnal transpiration).

  7. Insular Organization of Gene Space in Grass Genomes

    PubMed Central

    Massa, Alicia N.; Wanjugi, Humphrey; Deal, Karin R.; You, Frank M.; Xu, Xiangyang; Gu, Yong Q.; Luo, Ming-Cheng; Anderson, Olin D.; Chan, Agnes P.; Rabinowicz, Pablo

    2013-01-01

    Wheat and maize genes were hypothesized to be clustered into islands but the hypothesis was not statistically tested. The hypothesis is statistically tested here in four grass species differing in genome size, Brachypodium distachyon, Oryza sativa, Sorghum bicolor, and Aegilops tauschii. Density functions obtained under a model where gene locations follow a homogeneous Poisson process and thus are not clustered are compared with a model-free situation quantified through a non-parametric density estimate. A simple homogeneous Poisson model for gene locations is not rejected for the small O. sativa and B. distachyon genomes, indicating that genes are distributed largely uniformly in those species, but is rejected for the larger S. bicolor and Ae. tauschii genomes, providing evidence for clustering of genes into islands. It is proposed to call the gene islands “gene insulae” to distinguish them from other types of gene clustering that have been proposed. An average S. bicolor and Ae. tauschii insula is estimated to contain 3.7 and 3.9 genes with an average intergenic distance within an insula of 2.1 and 16.5 kb, respectively. Inter-insular distances are greater than 8 and 81 kb and average 15.1 and 205 kb, in S. bicolor and Ae. tauschii, respectively. A greater gene density observed in the distal regions of the Ae. tauschii chromosomes is shown to be primarily caused by shortening of inter-insular distances. The comparison of the four grass genomes suggests that gene locations are largely a function of a homogeneous Poisson process in small genomes. Nonrandom insertions of LTR retroelements during genome expansion creates gene insulae, which become less dense and further apart with the increase in genome size. High concordance in relative lengths of orthologous intergenic distances among the investigated genomes including the maize genome suggests functional constraints on gene distribution in the grass genomes. PMID:23326580

  8. Insular organization of gene space in grass genomes.

    PubMed

    Gottlieb, Andrea; Müller, Hans-Georg; Massa, Alicia N; Wanjugi, Humphrey; Deal, Karin R; You, Frank M; Xu, Xiangyang; Gu, Yong Q; Luo, Ming-Cheng; Anderson, Olin D; Chan, Agnes P; Rabinowicz, Pablo; Devos, Katrien M; Dvorak, Jan

    2013-01-01

    Wheat and maize genes were hypothesized to be clustered into islands but the hypothesis was not statistically tested. The hypothesis is statistically tested here in four grass species differing in genome size, Brachypodium distachyon, Oryza sativa, Sorghum bicolor, and Aegilops tauschii. Density functions obtained under a model where gene locations follow a homogeneous Poisson process and thus are not clustered are compared with a model-free situation quantified through a non-parametric density estimate. A simple homogeneous Poisson model for gene locations is not rejected for the small O. sativa and B. distachyon genomes, indicating that genes are distributed largely uniformly in those species, but is rejected for the larger S. bicolor and Ae. tauschii genomes, providing evidence for clustering of genes into islands. It is proposed to call the gene islands "gene insulae" to distinguish them from other types of gene clustering that have been proposed. An average S. bicolor and Ae. tauschii insula is estimated to contain 3.7 and 3.9 genes with an average intergenic distance within an insula of 2.1 and 16.5 kb, respectively. Inter-insular distances are greater than 8 and 81 kb and average 15.1 and 205 kb, in S. bicolor and Ae. tauschii, respectively. A greater gene density observed in the distal regions of the Ae. tauschii chromosomes is shown to be primarily caused by shortening of inter-insular distances. The comparison of the four grass genomes suggests that gene locations are largely a function of a homogeneous Poisson process in small genomes. Nonrandom insertions of LTR retroelements during genome expansion creates gene insulae, which become less dense and further apart with the increase in genome size. High concordance in relative lengths of orthologous intergenic distances among the investigated genomes including the maize genome suggests functional constraints on gene distribution in the grass genomes.

  9. Evapotranspiration parameterizations at a grass site in Florida, USA

    USGS Publications Warehouse

    Rizou, M.; Sumner, David M.; Nnadi, F.

    2007-01-01

    In spite of the fact that grasslands account for about 40% of the ice-free global terrestrial land cover, their contribution to the surface exchanges of energy and water in local and regional scale is so far uncertain. In this study, the sensitivity of evapotranspiration (ET) and other energy fluxes to wetness variables, namely the volumetric Soil Water Content (SWC) and Antecedent Precipitation Index (API), over a non-irrigated grass site in Central Florida, USA (28.049 N, 81.400 W) were investigated. Eddy correlation and soil water content measurements were taken by USGS (U.S. Geological Survey) at the grass study site, within 100 m of a SFWMD (South Florida Water Management District) weather station. The soil is composed of fine sands and it is mainly covered by Paspalum notatum (bahia grass). Variable soil wetness conditions with API bounds of about 2 to 160 mm and water table levels of 0.03 to 1.22 m below ground surface, respectively, were observed throughout the year 2004. The Bowen ratio exhibited an average of 1 and values larger than 2 during few dry days. The daytime average ET was classified into two stages, first stage (energy-limited) and second stage (water- limited) based on the water availability. The critical values of API and SWC were found to be about 56 mm and 0.17 respectively, with the second one being approximately 33% of the SWC at saturation. The ET values estimated by the simple Priestley-Taylor (PT) method were compared to the actual values. The PT coefficient varied from a low bound of approximately 0.4 to a peak of 1.21. Simple relationships for the PT empirical factor were employed in terms of SWC and API to improve the accuracy of the second stage observations. The results of the ET parameterizations closely match eddy-covariance flux values on daily and longer time steps.

  10. Use of vetiver grass constructed wetland for treatment of leachate.

    PubMed

    Bwire, K M; Njau, K N; Minja, R J A

    2011-01-01

    Performance of Constructed Wetland planted with vetiver grasses for the treatment of leachate was investigated in controlled experiments involving horizontal subsurface flow constructed wetland (HSSFCW). The HSSFCW experimental unit had two cells, one planted with vetiver grasses and another bare. Both units were packed with limestone gravel as substrate and were operated with equal hydraulic loading and hydraulic retention time. Collected samples of influents and effluents were analysed for COD, Cr, Pb, Fe and pH. The results showed that vetiver grasses tolerated leachate with high loading of COD up to 14,000 mg L(-1). The planted cell outperformed the unplanted cell in terms of COD, Cr, Pb and Fe removal. The systems showed optimum points for COD and Pb removal as a function of feed concentrations. The optimum COD removal values of 210 mgm(-2) day(-1) at feed COD concentration of 11,200 mg COD L(-1) and 89 mgm(-2) day(-1) at feed concentration of 7,200 mg COD L(-1) were obtained for planted and unplanted cells respectively. Similarly Pb removal values of 0.0132 mgm(-2) day(-1) at 1.0 mg Pb L(-1) and 0.0052 mgm(-2) day(-1) at 1.04 mgPb L(-1) were obtained for planted and unplanted units respectively. Removal of Fe as a function of feed Fe concentration showed a parabolic behaviour but Cr removal showed linear behaviour with feed Cr concentrations in both units. The system showed very good removal efficiencies with Cr and Fe but poor efficiencies were recorded for Pb.

  11. Grass buffers for playas in agricultural landscapes: A literature synthesis

    USGS Publications Warehouse

    Melcher, Cynthia P.; Skagen, Susan K.

    2005-01-01

    Future research should entail multiple-scale approaches at regional, wetland-complex, and individual watershed scales. Information needs include direct measures of buffer effectiveness in ‘real-world’ systems, refinement and field tests of buffer-effectiveness models, how buffers may affect floral and faunal communities of playas, and basic ecological information on playa function and playa wildlife ecology. Understanding how wildlife communities respond to patch size and habitat fragmentation is crucial for addressing questions regarding habitat quality of grass buffers in playa systems.

  12. GRASS 3.0 Programmer’s Manual

    DTIC Science & Technology

    1989-09-01

    USACERL ADP Report N 89/14 ~I~jAD-A252 461 September 1989US.,i my orps 1111 l 1 Mlill/ti ill’ 11, of Engineers Construction Engineering Research ...Engineering Research Laboratory (USACERL) ADP N-89/14 P0 Box 9(X)5 Champaign, IL 61826-9005 9. SPONSOR ING/MONITORING AGENCY NAME(S) AND ADORESS(ES...developed by researchers at the U.S. Army Construction Engireering Research Laboratory (USACERL). GRASS provides software capabilities suitable for

  13. Men are grass: Bateson, Erickson, utilization and metaphor.

    PubMed

    Roffman, Andrew E

    2008-01-01

    The relationship between metaphor and the practice of utilization in therapy and hypnosis can be seen as dependent on metaphor's role in structuring experience. The work of Gregory Bateson and others is used to illustrate how metaphor functions. Bateson's comparison of two forms of syllogistic logic provides a background for distinguishing between the experiential effects of metaphor in contrast to the categorical thinking inherent in simile and analogy. Clinical examples are given to demonstrate how utilization is structured by metaphor, particularly as Bateson has described it in his analysis of the Syllogism in Grass.

  14. Stimulation of glycerol kinase in grass carp preadipocytes by EPA.

    PubMed

    Lei, Caixia; Tian, Jingjing; Ji, Hong

    2017-01-05

    This study was conducted to assess the effect of eicosapentaenoic acid (EPA) on grass carp preadipocyte glycerol kinase (GyK) expression, as well as to explore the mechanism. Here, we cloned partial sequence of grass carp GyK gene and analyzed its tissue distribution. The result showed that GyK gene expressed most in the liver, followed by adipose tissue and the kidney. Besides, 400 μM oleic acid (18:1n-9, OA) was used to establish a hypertrophic preadipocyte model. GyK gene expression and enzyme activity were significantly enhanced after model cells were treated with 100 μM eicosapentaenoic acid (20:5n-3, EPA) for 6, 12, and 24 h. Meanwhile, peroxisome proliferative-activated receptor (PPAR)γ, adipose triglyceride lipase (ATGL), and the two isoforms of grass carp HSL gene were first identified by Sun et al (2016), and they defined the two isoforms as HSLa and HSLb. Therefore, maybe HSLa and HSLb are appropriate.. The content of triglyceride was dramatically increased by EPA treatment for 24 h. Further, a competitive ATGL antagonist, HY-15859, attenuated the increase in GyK induced by EPA at 12 h. Surprisingly, the enhanced lipolysis and PPARγ gene expression induced by serum deprivation were paralleled by an increase in GyK gene expression, whereas a stabilization in GyK enzyme activity. Other fatty acids, including docosahexaenoic acid, alpha-linolenic acid, linoleic acid, and OA also promoted GyK gene expression. Moreover, an irreversible PPARγ antagonist, GW9662, was used to investigate the role of PPARγ in GyK induction. Data showed that GW9662 abolished the induction of GyK by EPA at 12 h. Together, these data suggested that EPA elevated grass carp preadipocytes GyK expression. ATGL and PPARγ contributed to the induction of GyK. PPARγ may be a key regulator in response to GyK expression induced by EPA.

  15. Evaluating nitrogen utilization efficiency of nonpregnant dry cows offered solely fresh cut grass at maintenance levels.

    PubMed

    Stergiadis, S; Chen, X J; Allen, M; Wills, D; Yan, T

    2015-02-01

    The present study aimed to identify key parameters influencing N utilization and develop prediction equations for manure N output (MN), feces N output (FN), and urine N output (UN). Data were obtained under a series of digestibility trials with nonpregnant dry cows fed fresh grass at maintenance level. Grass was cut from 8 different ryegrass swards measured from early to late maturity in 2007 and 2008 (2 primary growth, 3 first regrowth, and 3 second regrowth) and from 2 primary growth early maturity swards in 2009. Each grass was offered to a group of 4 cows and 2 groups were used in each of the 8 swards in 2007 and 2008 for daily measurements over 6 wk; the first group (first 3 wk) and the second group (last 3 wk) assessed early and late maturity grass, respectively. Average values of continuous 3-d data of N intake (NI) and output for individual cows ( = 464) and grass nutrient contents ( = 116) were used in the statistical analysis. Grass N content was positively related to GE and ME contents but negatively related to grass water-soluble carbohydrates (WSC), NDF, and ADF contents ( < 0.01), indicating that accounting for nutrient interrelations is a crucial aspect of N mitigation. Significantly greater ratios of UN:FN, UN:MN, and UN:NI were found with increased grass WSC contents and ratios of N:WSC, N:digestible OM in total DM (DOMD), and N:ME ( < 0.01). Greater NI, animal BW, and grass N contents and lower grass WSC, NDF, ADF, DOMD, and ME concentrations were significantly associated with greater MN, FN, and UN ( < 0.05). The present study highlighted that using grass lower in N and greater in fermentable energy in animals fed solely fresh grass at maintenance level can improve N utilization, reduce N outputs, and shift part of N excretion toward feces rather than urine. These outcomes are highly desirable in mitigation strategies to reduce nitrous oxide emissions from livestock. Equations predicting N output from BW and grass N content explained a similar

  16. Induced gynogenesis in grass carp (Ctenopharyngodon idellus) using irradiated sperm of allotetraploid hybrids.

    PubMed

    Zhang, Hong; Liu, ShaoJun; Zhang, Chun; Tao, Min; Peng, LiangYue; You, CuiPing; Xiao, Jun; Zhou, Yi; Zhou, GongJian; Luo, KaiKun; Liu, Yun

    2011-10-01

    Grass carp (Ctenopharyngodon idellus) eggs were activated by UV-irradiated diploid sperm of allotetraploid hybrids derived from red crucian carp (♀) × common carp (♂) and then duplicated by cold shock in 4-6°C water for 10-12 min. Different cold shock initiation times resulted in two types of diploid gynogenetic grass carp: meiotic gynogenetic (meiG) and mitotic gynogenetic (mitG). Over a 5-year period, a total of 17,170 meiG and 1,080 mitG fry were produced and 6,862 meiG and 372 mitG grass carp survived. The gynogenetic fish were confirmed by morphological characteristics, chromosome examination, and microsatellite DNA analysis. The morphological traits of the gynogenetic grass carp were similar to those of wild diploid grass carp. Normal gynogenetic fish were identified as diploid with 48 chromosomes by chromosomal metaphases examination, while nonviable abnormal embryos were detected as haploid with 24 chromosomes. Microsatellite DNA analysis indicated that after one generation of gynogenesis, the genetic purity of meiG and mitG grass carp was significantly increased over that of wild grass carp. In addition, both meiG and mitG grass carp groups were 100% female, and 88% of these showed normal ovary development. Thus, the sex determination mechanism in female grass carp was homogamety. The ability to establish pure all-female groups of meiG and mitG grass carp should be a valuable contribution to both fish genetics and grass carp breeding.

  17. Testing framework for GRASS GIS: ensuring reproducibility of scientific geospatial computing

    NASA Astrophysics Data System (ADS)

    Petras, V.; Gebbert, S.

    2014-12-01

    GRASS GIS, a free and open source GIS, is used by many scientists directly or through other projects such as R or QGIS to perform geoprocessing tasks. Thus, a large number of scientific geospatial computations depend on quality and correct functionality of GRASS GIS. Automatic functionality testing is therefore necessary to ensure software reliability. Here we present a testing framework for GRASS GIS which addresses different needs of GRASS GIS and geospatial software in general. It allows to test GRASS tools (referred to as GRASS modules) and examine outputs including large raster and vector maps as well as temporal datasets. Furthermore, it enables to test all levels of GRASS GIS architecture including C and Python application programming interface and GRASS modules invoked as subprocesses. Since GRASS GIS is used as a platform for development of geospatial algorithms and models, the testing framework allows not only to test GRASS GIS core functionality but also tools developed by scientists as a part of their research. Using testing framework we can test GRASS GIS and related tools automatically and repetitively and thus detect errors caused by code changes and new developments. Tools and code are then easier to maintain which results in preserving reproducibility of scientific results over time. Similarly to open source code, the test results are publicly accessible, so that all current and potential users can see them. The usage of testing framework will be presented on an example of a test suite for r.slope.aspect module, a tool for computation of terrain slope, aspect, curvatures and other terrain characteristics.

  18. A high loading overland flow system: Impacts on soil characteristics, grass constituents, yields and nutrient removal.

    PubMed

    Wen, C G; Chen, T H; Hsu, F H; Lu, C H; Lin, J B; Chang, C H; Chang, S P; Lee, C S

    2007-04-01

    The objectives of this paper are to determine effects of different grass species and their harvests on pollutant removal, elucidate impacts on soil characteristics and grass constituents, observe grass yield and quantify nutrient uptake by vegetation in an overland flow system (OLFS). Polluted creek water was applied to eight channels in the OLFS, which were planted with Paragrass, Nilegrass, Cattail, and Vetiver, with each two channels being randomly planted with a given grass species. The grass in one channel was harvested while that in the other channel was not. At a high rate of 27.8 m d(-1) hydraulic loading, the removal efficiencies of conventional pollutants such as BOD, COD, suspended solids (SS), and total coliforms in wastewater are not affected by the type of the grasses species, but those of nitrogen and phosphorus are affected by different species. Overall average removal efficiencies of BOD, COD, SS, ammonia, total nitrogen, total phosphorus and total coliforms through the OLFS are 42%, 48%, 78%, 47%, 40%, 33% and 89%, respectively. The concentration of nitrate, however, increases due to nitrification. Soil characteristics in OLFS have been changed significantly; specific conductivity, organic matter, exchangeable magnesium, extractable copper and zinc in soils all increase with time while pHs decrease. During the winter season, there is a significant accumulation of nitrate in grass with the subsequent reduction during the active growing season (Spring). The contents of nitrate and phosphorus in grass tissue are higher than those of grass in general pastureland, probably due to nutrient luxury uptake by grass. The overall grass yield, growth rate and nutrient uptake are quantified and implication of such high rate OLFS discussed.

  19. Blue wild-rye grass competition increases the effect of ozone on ponderosa pine seedlings.

    PubMed

    Andersen, C P; Hogsett, W E; Plocher, M; Rodecap, K; Lee, E H

    2001-03-01

    Individual ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedlings were grown in mesocosms with three densities of blue wild-rye grass (Elymus glaucus Buckl.) (equivalent to 0, 32 or 88 plants m-2) to determine if the presence of a natural competitor alters the response of ponderosa pine seedlings to ozone. After 3 years of ozone exposure, grass presence reduced total ponderosa pine dry mass by nearly 50%, whereas ozone alone had no significant effect on ponderosa pine growth. The combination of ozone and grass further reduced needle, stem and branch dry mass significantly below that induced by grass competition alone. Root:shoot ratios increased in response to the combined grass and ozone treatments. Grass competition significantly reduced soluble sugar concentrations in all ponderosa pine tissue components examined. Starch concentrations were highly variable but did not differ significantly between treatments. Ozone significantly reduced soluble sugar concentrations in fine roots and stems. In the absence of grass, ozone-treated seedlings tended to have higher tissue N concentrations than controls. In the presence of grass, ozone-treated seedlings had lower N concentrations than controls, resulting in a significant interaction between these two stresses in 1- and 2-year-old needles. Needle C:N ratios decreased in response to grass competition, as a result of increased N concentration and no change in C concentration. The opposite response was observed in ozone-treated seedlings as a result of decreased N concentrations, indicating that ozone-treated seedlings were unable to take up or retain as much nitrogen when grown in the presence of grass. We conclude that ponderosa pine seedlings are more susceptible to ozone when grown in competition with blue wild-rye grass.

  20. Impact of grass cover on the magnetic susceptibility measurements for assessing metal contamination in urban topsoil.

    PubMed

    Golden, Nessa; Zhang, Chaosheng; Potito, Aaron P; Gibson, Paul J; Bargary, Norma; Morrison, Liam

    2017-03-02

    In recent decades, magnetic susceptibility monitoring has developed as a useful technique in environmental pollution studies, particularly metal contamination of soil. This study provides the first ever examination of the effects of grass cover on magnetic susceptibility (MS) measurements of underlying urban soils. Magnetic measurements were taken in situ to determine the effects on κ (volume magnetic susceptibility) when the grass layer was present (κ(grass)) and after the grass layer was trimmed down to the root (κ(no grass)). Height of grass was recorded in situ at each grid point. Soil samples (n=185) were collected and measurements of mass specific magnetic susceptibility (χ) were performed in the laboratory and frequency dependence (χfd%) calculated. Metal concentrations (Pb, Cu, Zn and Fe) in the soil samples were determined and a gradiometry survey carried out in situ on a section of the study area. Significant correlations were found between each of the MS measurements and the metal content of the soil at the p<0.01 level. Spatial distribution maps were created using Inverse Distance Weighting (IDW) and Local Indicators of Spatial Association (LISA) to identify common patterns. κ(grass) (ranged from 1.67 to 301.00×10(-5) SI) and κ(no grass) (ranged from 2.08 to 530.67×10(-5) SI) measured in situ are highly correlated [r=0.966, n=194, p<0.01]. The volume susceptibility datasets in the presence and absence of grass coverage share a similar spatial distribution pattern. This study re-evaluates in situ κ monitoring techniques and the results suggest that the removal of grass coverage prior to obtaining in situ κ measurements of urban soil is unnecessary. This layer does not impede the MS sensor from accurately measuring elevated κ in soils, and therefore κ measurements recorded with grass coverage present can be reliably used to identify areas of urban soil metal contamination.

  1. A specific CpG oligodeoxynucleotide induces protective antiviral responses against grass carp reovirus in grass carp Ctenopharyngodon idella.

    PubMed

    Su, Hang; Yuan, Gailing; Su, Jianguo

    2016-07-01

    CpG oligodeoxynucleotides (ODNs) show strong immune stimulatory activity in vertebrate, however, they possess specific sequence feature among species. In this study, we screened out an optimal CpG ODN sequence for grass carp (Ctenopharyngodon idella), 1670A 5'-TCGAACGTTTTAACGTTTTAACGTT-3', from six published sequences and three sequences designed by authors based on grass carp head kidney mononuclear cells and CIK (C. idella kidney) cells proliferation. VP4 mRNA expression was strongly inhibited by CpG ODN 1670A in CIK cells with GCRV infection, showing its strong antiviral activity. The mechanism via toll-like receptor 9 (TLR9)-mediated signaling pathway was measured by real-time quantitative RT-PCR, and TLR21 did not play a role in the immune response to CpG ODN. The late up-regulation of CiRIG-I mRNA expression indicated that RIG-I-like receptors (RLRs) signaling pathway participated in the immune response to CpG ODN which is the first report on the interaction between CpG and RLRs. We also found that the efficient CpG ODN can activates interferon system. Infected with GCRV, type I interferon expression was reduced and type II interferon was induced by the efficient CpG ODN in CIK cells, especially IFNγ2, suggesting that IFNγ2 played an important role in response to the efficient CpG ODN. These results provide a theoretical basis and new development trend for further research on CpG and the application of CpG vaccine adjuvant in grass carp disease control.

  2. Do urban canyons influence street level grass pollen concentrations?

    PubMed

    Peel, Robert George; Kennedy, Roy; Smith, Matt; Hertel, Ole

    2014-08-01

    In epidemiological studies, outdoor exposure to pollen is typically estimated using rooftop monitoring station data, whilst exposure overwhelmingly occurs at street level. In this study the relationship between street level and roof level grass pollen concentrations was investigated for city centre street canyon environments in Aarhus, Denmark, and London, UK, during the grass pollen seasons of 2010 and 2011 respectively. For the period mid-day to late evening, street level concentrations in both cities tended to be lower than roof-level concentrations, though this difference was found to be statistically significant only in London. The ratio of street/roof level concentrations was compared with temperature, relative humidity, wind speed and direction, and solar radiation. Results indicated that the concentration ratio responds to wind direction with respect to relative canyon orientation and local source distribution. In the London study, an increase in relative humidity was linked to a significant decrease in street/roof level concentration ratio, and a possible causative mechanism involving moisture mediated pollen grain buoyancy is proposed. Relationships with the other weather variables were not found to be significant in either location. These results suggest a tendency for monitoring station data to overestimate exposure in the canyon environment.

  3. The Sorghum bicolor genome and the diversification of grasses

    SciTech Connect

    Paterson, Andrew H.; Bowers, John E.; Bruggmann, Remy; dubchak, Inna; Grimwood, Jane; Gundlach, Heidrun; Haberer, Georg; Hellsten, Uffe; Mitros, Therese; Poliakov, Alexander; Schmutz, Jeremy; Spannagl, Manuel; Tang, Haibo; Wang, Xiyin; Wicker, Thomas; Bharti, Arvind K.; Chapman, Jarrod; Feltus, F. Alex; Gowik, Udo; Grigoriev, Igor V.; Lyons, Eric; Maher, Christopher A.; Martis, Mihaela; Marechania, Apurva; Otillar, Robert P.; Penning, Bryan W.; Salamov, Asaf. A.; Wang, Yu; Zhang, Lifang; Carpita, Nicholas C.; Freeling, Michael; Gingle, Alan R.; hash, C. Thomas; Keller, Beat; Klein, Patricia; Kresovich, Stephen; McCann, Maureen C.; Ming, Ray; Peterson, Daniel G.; ur-Rahman, Mehboob-; Ware, Doreen; Westhoff, Peter; Mayer, Klaus F. X.; Messing, Joachim; Rokhsar, Daniel S.

    2008-08-20

    Sorghum, an African grass related to sugar cane and maize, is grown for food, feed, fibre and fuel. We present an initial analysis of the approx730-megabase Sorghum bicolor (L.) Moench genome, placing approx98percent of genes in their chromosomal context using whole-genome shotgun sequence validated by genetic, physical and syntenic information. Genetic recombination is largely confined to about one-third of the sorghum genome with gene order and density similar to those of rice. Retrotransposon accumulation in recombinationally recalcitrant heterochromatin explains the approx75percent larger genome size of sorghum compared with rice. Although gene and repetitive DNA distributions have been preserved since palaeopolyploidization approx70 million years ago, most duplicated gene sets lost one member before the sorghum rice divergence. Concerted evolution makes one duplicated chromosomal segment appear to be only a few million years old. About 24percent of genes are grass-specific and 7percent are sorghum-specific. Recent gene and microRNA duplications may contribute to sorghum's drought tolerance.

  4. Silicification in Grasses: Variation between Different Cell Types

    PubMed Central

    Kumar, Santosh; Soukup, Milan; Elbaum, Rivka

    2017-01-01

    Plants take up silicon as mono-silicic acid, which is released to soil by the weathering of silicate minerals. Silicic acid can be taken up by plant roots passively or actively, and later it is deposited in its polymerized form as amorphous hydrated silica. Major silica depositions in grasses occur in root endodermis, leaf epidermal cells, and outer epidermal cells of inflorescence bracts. Debates are rife about the mechanism of silica deposition, and two contrasting scenarios are often proposed to explain it. According to the passive mode of silicification, silica deposition is a result of silicic acid condensation due to dehydration, such as during transpirational loss of water from the aboveground organs. In general, silicification and transpiration are positively correlated, and continued silicification is sometimes observed after cell and tissue maturity. The other mode of silicification proposes the involvement of some biological factors, and is based on observations that silicification is not necessarily coupled with transpiration. Here, we review evidence for both mechanisms of silicification, and propose that the deposition mechanism is specific to the cell type. Considering all the cell types together, our conclusion is that grass silica deposition can be divided into three modes: spontaneous cell wall silicification, directed cell wall silicification, and directed paramural silicification in silica cells.

  5. Absence of mammals and the evolution of New Zealand grasses.

    PubMed

    Antonelli, Alexandre; Humphreys, Aelys M; Lee, William G; Linder, H Peter

    2011-03-07

    Anthropogenic alteration of biotic distributions and disturbance regimes has dramatically changed the evolutionary context for the differentiation of species traits. Some of the most striking examples in recent centuries have been on islands where flightless birds, which evolved in the absence of mammalian carnivores, have been decimated following the widespread introduction of exotic predators. Until now, no equivalent case has been reported for plants. Here, we make use of robust analytical tools and an exceptionally well-sampled molecular phylogeny to show that a majority of New Zealand danthonioid grasses (Poaceae) may have adapted to the relaxed vertebrate herbivore pressure during the late Cenozoic through the development of a distinctive and unusual habit: abscission of old leaves. This feature occurs in only about 3 per cent of the world's roughly 11,000 grass species and has been empirically shown to increase plant productivity but to reduce protection against mammal grazing. This result suggests that release from a selective pressure can lead to species radiations. This seemingly anachronistic adaptation may represent an overlooked factor contributing to the severe decline in the geographical extent and species diversity of New Zealand's indigenous grasslands following the introduction of herbivorous terrestrial mammals in the 19th century.

  6. Red edge shift and biochemical content in grass canopies

    NASA Astrophysics Data System (ADS)

    Mutanga, Onisimo; Skidmore, Andrew K.

    The concentration of foliar nitrogen in tropical grass is one of the factors that explain the distribution of wildlife. Therefore, the remote sensing of foliar nitrogen contributes to a better understanding of wildlife feeding patterns. This study evaluated changes in the red edge position of the 680 nm continuum removed chlorophyll feature in the reflectance spectra of samples of Cenchus ciliaris grass grown in a greenhouse under three levels of nitrogen supply. Canopy spectral measurements from each treatment were recorded under controlled laboratory conditions over a four-week period using a GER 3700 spectroradiometer. Results indicate that the mean wavelength positions of the three fertilization treatments were statistically different. An increase in nitrogen supply yielded a shift in the red edge position to longer wavelengths. The red edge position, amplitude, slope at 713 nm and slope at 725 nm were significantly correlated to measured nitrogen concentration (bootstrapped r = 0.89, - 0.28, 0.63 and 0.75, respectively) even at canopy level. Based on these results, the red edge position is strongly correlated with biochemical concentration in plants compared to the other methods tested. The study provides conclusive evidence that confirms the strength of a red edge-nitrogen relationship that remains underused in remote sensing. This method is promising for estimating nutrient content in grasslands.

  7. Molecular dating, evolutionary rates, and the age of the grasses.

    PubMed

    Christin, Pascal-Antoine; Spriggs, Elizabeth; Osborne, Colin P; Strömberg, Caroline A E; Salamin, Nicolas; Edwards, Erika J

    2014-03-01

    Many questions in evolutionary biology require an estimate of divergence times but, for groups with a sparse fossil record, such estimates rely heavily on molecular dating methods. The accuracy of these methods depends on both an adequate underlying model and the appropriate implementation of fossil evidence as calibration points. We explore the effect of these in Poaceae (grasses), a diverse plant lineage with a very limited fossil record, focusing particularly on dating the early divergences in the group. We show that molecular dating based on a data set of plastid markers is strongly dependent on the model assumptions. In particular, an acceleration of evolutionary rates at the base of Poaceae followed by a deceleration in the descendants strongly biases methods that assume an autocorrelation of rates. This problem can be circumvented by using markers that have lower rate variation, and we show that phylogenetic markers extracted from complete nuclear genomes can be a useful complement to the more commonly used plastid markers. However, estimates of divergence times remain strongly affected by different implementations of fossil calibration points. Analyses calibrated with only macrofossils lead to estimates for the age of core Poaceae ∼51-55 Ma, but the inclusion of microfossil evidence pushes this age to 74-82 Ma and leads to lower estimated evolutionary rates in grasses. These results emphasize the importance of considering markers from multiple genomes and alternative fossil placements when addressing evolutionary issues that depend on ages estimated for important groups.

  8. Biosynthesis and assembly of cell wall polysaccharides in cereal grasses

    SciTech Connect

    Carpita, N.C.

    1991-04-01

    We have just completed the second year of a three-year project entitled Biosynthesis assembly of cell wall polysaccharides in cereal grasses.'' We made significant progress on two aspects of cell wall synthesis in grasses and greatly refined gas-liquid and high- performance liquid chromatographic techniques necessary to identify the products of synthesis in vitro and in vivo. First, Dr. David Gibeaut, a post-doctoral associate, devised a convenient procedure for the enrichment of Golgi membranes by flotation centrifugation following initial downward rate-zonal separation. Based on comparison of the IDPase marker enzyme, flotation centrifugation enriched the Golgi apparatus almost 7-fold after the initial downward separation. This system is now used in our studies of the synthesis in vitro of the mixed-linkage {beta}-D-glucan. Second, Gibeaut and I have devised a simple technique to feed radioactive sugars into intact growing seedlings and follow incorporation of radioactivity into and turnover from specific cell wall polysaccharides. The project has also provided a few spin-off projects that have been productive as well. First, in collaboration with the group of Prof. Peter Kaufman, University of Michigan, we examined changes in cell wall structure concomitant with reaction to gravistimulation in the gravisensing oat pulvinus. Second, Dr. Gibeaut developed a simple clean-up procedure for partially methylated alditol derivatives to remove a large amount of undesirable interfering compounds that confound separation of the derivatives by gas-liquid chromatography. 5 refs.

  9. Estimating dry grass residues using landscape integration analysis

    NASA Technical Reports Server (NTRS)

    Hart, Quinn J.; Ustin, Susan L.; Duan, Lian; Scheer, George

    1993-01-01

    The acreage of grassland and grassland-savannah is extensive in California, making direct measurement and assessment logistically impossible. Grasslands cover the entire Central Valley up to about 1200 m elevation in the Coast Range and Sierra Nevada Range. Kuchler's map shows 5.35 M ha grassland with an additional 3.87 M ha in Oak savannah. The goal of this study was to examine the use of high spectral resolution sensors to distinguish between dry grass and soil in remotely sensed images. Spectral features that distinguish soils and dry plant material in the shortwave infrared (SWIR) region are thought to be primarily caused by cellulose and lignin, biochemicals which are absent from soils or occur as breakdown products in humid substances that lack the narrow-band features. We have used spectral mixing analysis (SMA) combined with Geographic Information Systems (GIS) analysis to characterize plant communities and dry grass biomass. The GIS was used to overlay elevation maps, and vegetation maps, with the SMA results. The advantage of non-image data is that it provides an independent source of information for the community classification.

  10. Molecular cloning, characterization and expression analysis of a heat shock protein 10 (Hsp10) from Pennisetum glaucum (L.), a C4 cereal plant from the semi-arid tropics.

    PubMed

    Nitnavare, Rahul B; Yeshvekar, Richa K; Sharma, Kiran K; Vadez, Vincent; Reddy, Malireddy K; Reddy, Palakolanu Sudhakar

    2016-08-01

    Heat shock proteins (Hsp10) belong to the ubiquitous family of heat-shock molecular chaperones found in the organelles of both prokaryotes and eukaryotes. Chaperonins assist the folding of nascent and stress-destabilized proteins. A cDNA clone encoding a 10 kDa Hsp was isolated from pearl millet, Pennisetum glaucum (L.) by screening a heat stress cDNA library. The fulllength PgHsp10 cDNA consisted of 297 bp open reading frame (ORF) encoding a 98 amino acid polypeptide with a predicted molecular mass of 10.61 kDa and an estimated isoelectric point (pI) of 7.95. PgHsp10 shares 70-98 % sequence identity with other plant homologs. Phylogenetic analysis revealed that PgHsp10 is evolutionarily close to the maize Hsp10 homolog. The predicted 3D model confirmed a conserved eight-stranded ß-barrel with active site between the ß-barrel comprising of eight-strands, with conserved domain VLLPEYGG sandwiched between two ß-sheets. The gene consisted of 3 exons and 2 introns, while the position and phasing of these introns were conserved similar to other plant Hsp10 family genes. In silico analysis of the promoter region of PgHsp10 presented several distinct set of cis-elements and transcription factor binding sites. Quantitative RT-PCR analysis showed that PgHsp10 gene was differentially expressed in response to abiotic stresses with the highest level of expression under heat stress conditions. Results of this study provide useful information regarding the role of chaperonins in stress regulation and generated leads for further elucidation of their function in plant stress tolerance.

  11. Cool-season grass sward structure influences intake of grazing cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cool-season grasses differ in sward structure, such as canopy height and the distribution of leaves and stems throughout the canopy, that may influence intake by grazing livestock. We determined the relationship between the sward structure of four grasses (meadow fescue, orchardgrass, quackgrass, an...

  12. Growth and Quality of Perennial C3 Grasses in the Southern Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spring and fall gaps in forage production for systems utilizing winter wheat forage in the Southern Great Plains have led to an interest in additional resources such as C3 perennial grasses. We evaluated the potential of nine cool-season grass entries for forage production and quality through the fa...

  13. Preliminary assessment of dual use bioenergy-forage potential of exotic and native grasses in Arkansas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some bioenergy grasses may have dual use potential as livestock feed or bioenergy feedstock. We conducted two studies on exotic and native grasses thought to have primary use as either livestock forage [‘Bumpers’ eastern gamagrass (Tripsacum dactyloides) and ‘Alamo’ switchgrass (Panicum virgatum)] ...

  14. Stripe smuts of grasses: one lineage or high levels of polyphyly?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stripe smut of grasses, Ustilago striiformis s.l., is caused by a complex of smut fungi widely distributed over temperate and subtropical regions. The disease results in the shredding and death of leaf tissue following the rupture of elongated sori. Nearly 100 different grass species in more than 30...

  15. Nucleotide sequence and genome organization of a novel Panicovirus from Bermuda grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bermuda grass, (Cynodon dactylon) is widely used in tropical and subtropical areas for golf greens, athletic fields, and landscapes. Samples of Bermuda grass associated with decline symptoms were tested at the University of Minnesota plant virology lab. Spherical virus particles (28-30 nm) were obse...

  16. Sod-seeding to modify coastal bermuda grass on reclaimed lignite overburden in Texas

    SciTech Connect

    Skousen, J.G.

    1986-01-01

    This study was conducted to investigate the ability of nine low-maintenance species to establish and persist with Coastal bermuda grass (Cynodon dactylon (L.) Pers.) established on reclaimed lignite overburden; to evaluate the establishment and persistence of seventeen low-maintenance species seeded in overburden with no vegetation cover; and to examine seeding mixtures and rates for establishing low-maintenance species into three cover types (bermuda grass, oats, (Avena fatua L.) and no cover). Seventeen low-maintenance species established and persisted in overburden without fertilization during years of low precipitation. Several seeded grasses showed sufficient stand development in monoculture for erosion control. Most of the other seeded species were slower in establishment, yet persisted on the site and promoted multiple use of the reclaimed area. Recommended seeding rates were generally adequate for seedling establishment in oat, bermuda grass, and no vegetation cover types. Sod-seeding into bermuda grass resulted in higher seedling densities than those in oats and no cover because of stored moisture beneath the sod during bermuda grass dormancy. Using /sup 15/N-labelled fertilizer, Coastal bermuda grass demonstrated the ability to rapidly recovery applied N. Maximilian sunflower (Helianthus maximiliani Schrad.) was suppressed by Coastal bermuda grass in mixture at all fertilizer N rates.

  17. Aminopyrald and Picloram reduce seed production of the invasive annual grasses Medusahead and Ventenata

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Invasive annual grasses are negatively impacting millions of hectares of U.S. rangelands. Sulfonylurea, amino acid synthesis inhibitor and photosynthesis inhibitor herbicides are sometimes used to control invasive annual grasses. On the other hand, growth regulator herbicides are widely used to co...

  18. From the lab bench: Mixtures of grasses and legumes; a good or bad thing?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A column was written to discuss the advantages of complex mixtures of grasses and legumes. Historically, Kentucky pastures have been primarily composed of toxic endophyte-infected tall fescue, but Kentucky bluegrass and other grasses are presently encroaching tall fescue pastures. These other gras...

  19. Wounding systemically activates a mitogen-activated protein kinase in forage and turf grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage and turf grasses are continually cut and grazed by livestock, however very little is known concerning the perception or molecular responses to wounding. Mechanical wounding rapidly activated a 46 kDa and a 44 kDa mitogen-activated protein kinase (MAPK) in six different grass species. In the m...

  20. Abiotic stresses activate a MAPkinase in the model grass species Lolium temulentum L.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage and turf grasses are utilized in diverse environments which exposes them to a variety of abiotic stresses, however very little is known concerning the perception or molecular responses to these various stresses. In the model grass species Lolium temulentum (Lt), a 46 kDa mitogen-activated pro...

  1. Preferential predation of cool season grass seed by the common cricket (Acheta domesticus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine if there might be a seed predation preference among forage grasses a laboratory study was conducted using the common cricket (Acheta domesticus L.). Six cool-season grasses were selected and feeding studies were conducted over a three day period. The study was designed as a randomized ...

  2. Seeding cool-season grasses to suppress white locoweed (Oxytropis sericea) reestablishment and increase forage production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock poisoning can occur on short-grass prairies when locoweeds (Astragalus and Oxytropis spp.) are actively growing in spring before warm-season grasses begin growth. White locoweed grows in early spring, completes flowering and seed production by early summer, and goes dormant. Perennial co...

  3. What Makes Responses Prepotent for Young Children? Insights from the Grass-Snow Task

    ERIC Educational Resources Information Center

    Simpson, Andrew; Riggs, Kevin J.

    2009-01-01

    Understanding how responses become prepotent is essential for understanding when inhibitory control is needed in everyday behaviour. We investigated prepotency in the grass-snow task--in which a child points to a green card when the experimenter says "snow" and a white card when the experimenter says "grass". Experiment 1 (n =…

  4. Distribution of infective gastrointestinal helminth larvae in tropical erect grass under different feeding systems for lambs.

    PubMed

    Tontini, Jalise Fabíola; Poli, Cesar Henrique Espírito Candal; Bremm, Carolina; de Castro, Juliane Machado; Fajardo, Neuza Maria; Sarout, Bruna Nunes Marsiglio; Castilhos, Zélia Maria de Souza

    2015-08-01

    This study examined tropical pasture contamination dynamics under different feeding systems for finishing lambs. The experiment aimed to evaluate the vertical distribution of gastrointestinal helminth infective larvae (L3) in erect grass subjected to grazing and to assess the parasite load and its impact on lamb performance in three production systems. Three treatments based on Aruana grass (Panicum maximum cv. IZ-5) were as follows: T1, grass only; T2, grass with 1.5% of body weight (BW) nutrient concentrate supplementation; and T3, grass with 2.5% BW concentrate supplementation. The randomized block design had three replicates of three treatments, with six lambs per replicate. L3 were recovered from three pasture strata (upper, middle, and bottom), each representing one third of the sward height, and correlated with microclimatic data. Significant differences (P < 0.05) were observed among treatments in the L3 recovery. Despite different grass heights between treatments and microclimates within the sward, the L3 concentration generally did not differ significantly among the three strata within a treatment (P > 0.05). Pasture microclimate did not correlate with larval recovery. At the end of the experiment, the animal fecal egg count was similar among treatments (P > 0.05). The results indicated that different lamb feeding systems in a tropical erect grassland caused differences in grass height but did not affect the distribution of infective larvae among strata. Larvae were found from the base to the top of the grass sward.

  5. Growth-defence balance in grass biomass production: the role of jasmonates.

    PubMed

    Shyu, Christine; Brutnell, Thomas P

    2015-07-01

    Growth-defence balance is the selective partitioning of resources between biomass accumulation and defence responses. Although it is generally postulated that reallocation of limited carbon pools drives the antagonism between growth and defence, little is known about the mechanisms underlying this regulation. Jasmonates (JAs) are a group of oxylipins that are required for a broad range of responses from defence against insects to reproductive growth. Application of JAs to seedlings also leads to inhibited growth and repression of photosynthesis, suggesting a role for JAs in regulating growth-defence balance. The majority of JA research uses dicot models such as Arabidopsis and tomato, while understanding of JA biology in monocot grasses, which comprise most bioenergy feedstocks, food for human consumption, and animal feed, is limited. Interestingly, JA mutants of grasses exhibit unique phenotypes compared with well-studied dicot models. Gene expression analyses in bioenergy grasses also suggest roles for JA in rhizome development, which has not been demonstrated in Arabidopsis. In this review we summarize current knowledge of JA biology in panicoid grasses-the group that consists of the world's emerging bioenergy grasses such as switchgrass, sugarcane, Miscanthus, and sorghum. We discuss outstanding questions regarding the role of JAs in panicoid grasses, and highlight the importance of utilizing emerging grass models for molecular studies to provide a basis for engineering bioenergy grasses that can maximize biomass accumulation while efficiently defending against stress.

  6. Beneficial effects of Neotyphodium tembladerae and Neotyphodium pampeanum on a wild forage grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asexual, vertically transmitted fungal endophytes of the genus Neotyphodium are considered to enhance growth, stress resistance and competitiveness of agronomic grasses, but have been suggested to have neutral or deleterious effects on wild grasses. We studied whether the associations between Bromus...

  7. Beneficial effects of neotyphodium tembladerae and neotyphodium pampeanum on a wild forage grass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Asexual, vertically transmitted fungal endophytes of the genus Neotyphodium are considered to enhance growth, stress resistance and competitiveness of agronomic grasses, but have been suggested to have neutral or deleterious effects on wild grasses. We studied whether the associations between Bromus...

  8. Narrow grass hedge control of nutrient loads following variable manure application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient transport in runoff has been shown to be reduced by the placement of stiff-stemmed grass hedges on the contour along a hill slope. This study was conducted to measure the effectiveness of a narrow grass hedge in reducing runoff nutrient transport soon after manure application. Beef cattle m...

  9. Endophytes of native grasses from South America:biodiversity and ecology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We review and present preliminary results of studies on cool-season grass endophytes native to South America. These fungi have been studied only in Argentina, where they have been detected in 36 native grass species. The hybrid Neotyphodium tembladerae is present in an extremely wide host range foun...

  10. The Occurrence of Balansioid Endophytes in Georgia, Florida, and Southern Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A collection of toxic fungal endophytes of grasses were detailed in terms of their morphology and taxonomy in detailed slides useful for identification of the little know species of Balansia or clavicipitalean fungi that are found on southern pasture and weed grass species. We have established as ...

  11. Update on occurrence of stripe smut and bunt in grasses grown for seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In disease surveys of orchard grass fields in western Oregon, stripe smut, caused by Ustilago striiformis, was detected in about a third of the orchard grass fields in 2004 and 2005, but less than 10% of the fields in 2006. Stripe smut was found in one field of bentgrass, but not in chewings fescue,...

  12. Response of Broom Snakeweed (Gutierrezia sarothrae) and Cool-Season Grasses to Defoliation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Livestock poisoning can occur on short-grass prairies when locoweeds (Astragalus and Oxytropis spp.) are actively growing in spring before warm-season grasses begin growth. White locoweed grows in early spring, completes flowering and seed production by early summer, and goes dormant. Perennial co...

  13. Seasonal and Maturity Effects on Forage Quality of Alfalfa and Grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Relationships among maturity, yield, and quality have been widely documented in alfalfa and temperate grasses. Studies conducted at multiple locations determined the rate of change for different harvest periods and for different grass species. Alfalfa was harvested in the spring, early summer, lat...

  14. Effects of grass and shrub cover on the critical unit stream power in overland flow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improved knowledge of the effect of grass and shrub cover in overland flow can provide valuable information for soil and water conservation programs. Laboratory simulated rainfall studies were conducted to determine the effect of grasses and shrubs on runoff and soil loss and to ascertain the relati...

  15. Development of fine-leaved Festuca grass for forage and wildfire control in the Great Basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drought and heat tolerant fine-leaved fescue (Festuca ssp.) grasses have potential as components in rangeland greenstrips for wildfire control in semi-arid climates, although such grasses have not been evaluated under rangeland conditions. Therefore, 64 geographically diverse Festuca accessions of ...

  16. Transcriptome sequencing identifies novel persistent viruses in herbicide resistant wild-grasses.

    PubMed

    Sabbadin, Federico; Glover, Rachel; Stafford, Rebecca; Rozado-Aguirre, Zuriñe; Boonham, Neil; Adams, Ian; Mumford, Rick; Edwards, Robert

    2017-02-06

    Herbicide resistance in wild grasses is widespread in the UK, with non-target site resistance (NTSR) to multiple chemistries being particularly problematic in weed control. As a complex trait, NTSR is driven by complex evolutionary pressures and the growing awareness of the role of the phytobiome in plant abiotic stress tolerance, led us to sequence the transcriptomes of herbicide resistant and susceptible populations of black-grass and annual rye-grass for the presence of endophytes. Black-grass (Alopecurus myosuroides; Am) populations, displaying no overt disease symptoms, contained three previously undescribed viruses belonging to the Partititiviridae (AMPV1 and AMPV2) and Rhabdoviridae (AMVV1) families. These infections were widespread in UK black-grass populations and evidence was obtained for similar viruses being present in annual rye grass (Lolium rigidum), perennial rye-grass (Lolium perenne) and meadow fescue (Festuca pratensis). In black-grass, while no direct causative link was established linking viral infection to herbicide resistance, transcriptome sequencing showed a high incidence of infection in the NTSR Peldon population. The widespread infection of these weeds by little characterised and persistent viruses and their potential evolutionary role in enhancing plant stress tolerance mechanisms including NTSR warrants further investigation.

  17. Multiscale drivers of spatially variable grass production and loss in the Chihuahuan Desert

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historic regime shifts from grass- to shrub-dominated states have been widespread in the Chihuahuan Desert and other arid and semiarid regions globally. These patterns of grass production and shifts to shrub dominance are spatially variable, and show a weak correlation with precipitation, suggesting...

  18. Transcriptome sequencing identifies novel persistent viruses in herbicide resistant wild-grasses

    PubMed Central

    Sabbadin, Federico; Glover, Rachel; Stafford, Rebecca; Rozado-Aguirre, Zuriñe; Boonham, Neil; Adams, Ian; Mumford, Rick; Edwards, Robert

    2017-01-01

    Herbicide resistance in wild grasses is widespread in the UK, with non-target site resistance (NTSR) to multiple chemistries being particularly problematic in weed control. As a complex trait, NTSR is driven by complex evolutionary pressures and the growing awareness of the role of the phytobiome in plant abiotic stress tolerance, led us to sequence the transcriptomes of herbicide resistant and susceptible populations of black-grass and annual rye-grass for the presence of endophytes. Black-grass (Alopecurus myosuroides; Am) populations, displaying no overt disease symptoms, contained three previously undescribed viruses belonging to the Partititiviridae (AMPV1 and AMPV2) and Rhabdoviridae (AMVV1) families. These infections were widespread in UK black-grass populations and evidence was obtained for similar viruses being present in annual rye grass (Lolium rigidum), perennial rye-grass (Lolium perenne) and meadow fescue (Festuca pratensis). In black-grass, while no direct causative link was established linking viral infection to herbicide resistance, transcriptome sequencing showed a high incidence of infection in the NTSR Peldon population. The widespread infection of these weeds by little characterised and persistent viruses and their potential evolutionary role in enhancing plant stress tolerance mechanisms including NTSR warrants further investigation. PMID:28165016

  19. Image analysis of anatomical traits in stalk transections of maize and other grasses

    DOE PAGES

    Heckwolf, Sven; Heckwolf, Marlies; Kaeppler, Shawn M.; ...

    2015-04-09

    Grass stalks architecturally support leaves and reproductive structures, functionally support the transport of water and nutrients, and are harvested for multiple agricultural uses. Research on these basic and applied aspects of grass stalks would benefit from improved capabilities for measuring internal anatomical features. In particular, methods suitable for phenotyping populations of plants are needed.

  20. Proteome analysis of leaves of the desiccation-tolerant grass, sporobolus stapfianus, in response to desiccation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sporobolus stapfianus is a resurrection grass native to South Africa which can tolerate the complete drying of its vegetative tissue structure; i.e., desiccation, and recover fully within hours of rewetting. Gene expression studies have demonstrated that the grass employs a strategy of gene inductio...

  1. Grass pea and neurolathyrism: farmers' perception on its consumption and protective measure in North Shewa, Ethiopia.

    PubMed

    Girma, Anteneh; Tefera, Beneberu; Dadi, Legesse

    2011-03-01

    Neurolathyrism in Ethiopia is caused by food dependency on grass pea (Lathyrus sativus L.). In the study area, a large proportion of the farmers are growing grass pea since it can withstand harsh environments. Socio-economic factors (poverty; lack of money to buy other food legumes) and environmental problems (such as water logging and frost hazards) influence consumption of grass pea. Most of the respondents have the idea that some chemical contained in grass pea causes a health problem. Different processing and preparation methods are used to prepare grass pea into different food forms. The major processing methods include washing and soaking, as the farmers apply these methods mainly because they assume that the chemical that causes lathyrism, scientifically known as β-ODAP (β-N-oxalyl-L-α,β-diaminopropionic acid) is reduced through washing and soaking. The farmers adopt different strategies to avoid the problem of lathyrism such as avoiding consumption of grass pea in the form that they suspect to cause the problem, blending/mixing with other crops, applying different processing/detoxification methods. Since grass pea is consumed with a fear of lathyrism, future research should concentrate either on developing grass pea varieties with safe level of β-ODAP content or improving the traditional/indigenous processing methods.

  2. Effects of Planting Date on Biomass Production by Grass pea (Lathyrus sativus L.).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grass pea is a cool-season legume commonly grown for human consumption and livestock feed in Asia and East Africa. A better understanding of the agronomic importance of planting date and the influence of photoperiod may lead to improved management strategies for cultivation of grass pea in the sout...

  3. From the Lab Bench: A special use for warm-season grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A column was written to discuss the uses of warm-season annual and perennial grasses in Kentucky. These grasses are typically planted in small acreages on a farm to provide grazing during the summer slump in growth of tall fescue pastures. Moving cattle from toxic endophyte-infected tall fescue pa...

  4. Brachypodium as a model for the grasses: today and the future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past several years, Brachypodium distachyon (Brachypodium) has emerged as a tractable model system to study biological questions relevant to the grasses. To place its relevance in the larger context of plant biology, we outline here the expanding adoption of Brachypodium as a model grass an...

  5. EFFECTS OF FOOD AVAILABILITY ON SURVIVAL, GROWTH, AND REPRODUCTION OF THE GRASS SHRIMP PALAEMONETES PUGIO: A LABORATORY STUDY

    EPA Science Inventory

    Grass shrimp are abundant, ecologically important inhabitants of estuarine ecosystems; adults and embryos have been used extensively in laboratory experiments, including studies of the impacts of environmental toxicants. However, optimal laboratory feeding conditions for grass sh...

  6. Disaggregating tree and grass phenology in tropical savannas

    NASA Astrophysics Data System (ADS)

    Zhou, Qiang

    Savannas are mixed tree-grass systems and as one of the world's largest biomes represent an important component of the Earth system affecting water and energy balances, carbon sequestration and biodiversity as well as supporting large human populations. Savanna vegetation structure and its distribution, however, may change because of major anthropogenic disturbances from climate change, wildfire, agriculture, and livestock production. The overstory and understory may have different water use strategies, different nutrient requirements and have different responses to fire and climate variation. The accurate measurement of the spatial distribution and structure of the overstory and understory are essential for understanding the savanna ecosystem. This project developed a workflow for separating the dynamics of the overstory and understory fractional cover in savannas at the continental scale (Australia, South America, and Africa). Previous studies have successfully separated the phenology of Australian savanna vegetation into persistent and seasonal greenness using time series decomposition, and into fractions of photosynthetic vegetation (PV), non-photosynthetic vegetation (NPV) and bare soil (BS) using linear unmixing. This study combined these methods to separate the understory and overstory signal in both the green and senescent phenological stages using remotely sensed imagery from the MODIS (MODerate resolution Imaging Spectroradiometer) sensor. The methods and parameters were adjusted based on the vegetation variation. The workflow was first tested at the Australian site. Here the PV estimates for overstory and understory showed best performance, however NPV estimates exhibited spatial variation in validation relationships. At the South American site (Cerrado), an additional method based on frequency unmixing was developed to separate green vegetation components with similar phenology. When the decomposition and frequency methods were compared, the frequency

  7. [Mechanisms of grass in slope erosion control in Loess sandy soil region of Northwest China].

    PubMed

    Zhao, Chun-Hong; Gao, Jian-En; Xu, Zhen

    2013-01-01

    By adopting the method of simulated precipitation and from the viewpoint of slope hydrodynamics, in combining with the analysis of soil resistance to erosion, a quantitative study was made on the mechanisms of grass in controlling the slope erosion in the cross area of wind-water erosion in Loess Plateau of Northwest China under different combinations of rainfall intensity and slope gradient, aimed to provide basis to reveal the mechanisms of vegetation in controlling soil erosion and to select appropriate vegetation for the soil and water conservation in Loess Plateau. The grass Astragalus adsurgens with the coverage about 40% could effectively control the slope erosion. This grass had an efficiency of more than 70% in reducing sediment, and the grass root had a greater effect than grass canopy. On bare slope and on the slopes with the grass plant or only the grass root playing effect, there existed a functional relation between the flow velocity on the slopes and the rainfall intensity and slope gradient (V = DJ(0.33 i 0.5), where V is flow velocity, D is the comprehensive coefficient which varies with different underlying surfaces, i is rainfall intensity, and J is slope gradient). Both the grass root and the grass canopy could markedly decrease the flow velocity on the slopes, and increase the slope resistance, but the effect of grass root in decreasing flow velocity was greater while the effect in increasing resistance was smaller than that of grass canopy. The effect of grass root in increasing slope resistance was mainly achieved by increasing the sediment grain resistance, while the effect of canopy was mainly achieved by increasing the slope form resistance and wave resistance. The evaluation of the soil resistance to erosion by using a conceptual model of sediment generation by overland flow indicated that the critical shear stress value of bare slope and of the slopes with the grass plant or only the grass root playing effect was 0.533, 1.672 and 0

  8. Feasibility of incorporating waste grass clippings (Lolium perenne L.) in particleboard composites.

    PubMed

    Nemli, Gökay; Demirel, Samet; Gümüşkaya, Esat; Aslan, Mustafa; Acar, Cengiz

    2009-03-01

    This study investigated some of the important physical (thickness swelling) and mechanical (modulus of rupture, modulus of elasticity and internal bond) properties of single-layer particleboard panels made from eucalyptus (Eucalyptus camaldulensis Dehn.), waste of grass clippings (Lolium perenne L.) and combinations of the two. The chemical properties (pH, holocelluse and alpha cellulose contents, and water, alcohol-benzene and 1% sodium hydroxide solubilities) of the raw materials were also determined. Panels with a 6:94 ratio of grass-to-eucalyptus particles had the required mechanical properties for interior fitments including furniture and general uses. Boards manufactured with 100% grass clippings exhibited the lowest quality. The overall panel properties improved with a lower percentage of grass clippings added. Based on initial results, it also appears that grass should compose no more than 13% to achieve acceptable panel properties for interior fitments and general uses.

  9. 355, 532, and 1064 nm picosecond laser interaction with grass tissues

    NASA Astrophysics Data System (ADS)

    Kim, Jaehun; Ki, Hyungson

    2012-12-01

    In this article, we investigate how 355, 532, and 1064 nm picosecond lasers interact with grass tissues. We have identified five interaction regimes, and based on this classification, interaction maps have been constructed from a systematic experiment. The optical properties of light absorbing grass constituents are studied theoretically in order to understand how and how much light is absorbed by grass tissues. Scanning electron microscopy and optical microscopy are employed for observing morphological and structural changes of grass tissues. To the best of the authors' knowledge, this is the first investigation into laser interaction with plant leaves and reveals some fundamental findings regarding how a laser interacts with grass tissues and how plant leaves can be processed using lasers.

  10. Reed canary grass as a feedstock for 2nd generation bioethanol production.

    PubMed

    Kallioinen, Anne; Uusitalo, Jaana; Pahkala, Katri; Kontturi, Markku; Viikari, Liisa; Weymarn, Niklas von; Siika-Aho, Matti

    2012-11-01

    The enzymatic hydrolysis and fermentation of reed canary grass, harvested in the spring or autumn, and barley straw were studied. Steam pretreated materials were efficiently hydrolysed by commercial enzymes with a dosage of 10-20FPU/g d.m. Reed canary grass harvested in the spring was hydrolysed more efficiently than the autumn-harvested reed canary grass. Additional β-glucosidase improved the release of glucose and xylose during the hydrolysis reaction. The hydrolysis rate and level of reed canary grass with a commercial Trichoderma reesei cellulase could be improved by supplementation of purified enzymes. The addition of CBH II improved the hydrolysis level by 10% in 48hours' hydrolysis. Efficient mixing was shown to be important for hydrolysis already at 10% dry matter consistency. The highest ethanol concentration (20g/l) and yield (82%) was obtained with reed canary grass at 10% d.m. consistency.

  11. Linking the biology and physics of multifunctional grasses and soil hydrological function

    NASA Astrophysics Data System (ADS)

    MacLeod, C. J. A.; Binley, A.; Haygarth, P. M.; Humphreys, M. W.; Joynes, A.; Papadopoulos, A.; Skot, L.; Turner, L. B.; Watts, C.; Whalley, W. R.

    2009-04-01

    Sustainable grassland systems need to function during periods of water deficit and excess. Traditionally, forage grasses have been bred for drought resistance and winter hardiness traits. There is a need to select for and grow grass cultivars under drought and water logged conditions, whilst delivering environmental services. A limited number of studies have been carried out on inter-species variability of plant water status and growth during periods of water deficit. However, little is known about how different grasses influence soil profile hydraulic properties. We have established and monitored the influence of grass type on soil hydrological properties and rainfall-runoff relationships. Changes in soil hydrological properties have been monitored using a range of soil physical and geophysical methods. In this paper we report on a large interdisciplinary project that is advancing our understanding of how grass selection may benefit soil hydraulic functioning during periods of water excess.

  12. Phytostabilisation potential of lemon grass (Cymbopogon flexuosus (Nees ex Stend) Wats) on iron ore tailings.

    PubMed

    Mohanty, M; Dhal, N K; Patra, P; Das, B; Reddy, P S R

    2012-01-01

    The present pot culture study was carried out for the potential phytostabilisation of iron ore tailings using lemon grass (Cymbopogon flexuosus) a drought tolerant, perennial, aromatic grass. Experiments have been conducted by varying the composition of garden soil (control) with iron ore tailings. The various parameters, viz. growth of plants, number of tillers, biomass and oil content of lemon grass are evaluated. The studies have indicated that growth parameters of lemon grass in 1:1 composition of garden soil and iron ore tailings are significantly more (-5% increase) compared to plants grown in control soil. However, the oil content of lemon grass in both the cases more or less remained same. The results also infer that at higher proportion of tailings the yield of biomass decreases. The studies indicate that lemongrass with its fibrous root system is proved to be an efficient soil binder by preventing soil erosion.

  13. On the causes of variability in amounts of airborne grass pollen in Melbourne, Australia

    NASA Astrophysics Data System (ADS)

    de Morton, Julian; Bye, John; Pezza, Alexandre; Newbigin, Edward

    2011-07-01

    In Melbourne, Australia, airborne grass pollen is the predominant cause of hay fever (seasonal rhinitis) during late spring and early summer, with levels of airborne grass pollen also influencing hospital admissions for asthma. In order to improve predictions of conditions that are potentially hazardous to susceptible individuals, we have sought to better understand the causes of diurnal, intra-seasonal and inter-seasonal variability of atmospheric grass pollen concentrations (APC) by analysing grass pollen count data for Melbourne for 16 grass pollen seasons from 1991 to 2008 (except 1994 and 1995). Some of notable features identified in this analysis were that on days when either extreme (>100 pollen grains m-3) or high (50-100 pollen grains m-3) levels of grass pollen were recorded the winds were of continental origin. In contrast, on days with a low (<20 pollen grains m-3) concentration of grass pollen, winds were of maritime origin. On extreme and high grass pollen days, a peak in APC occurred on average around 1730 hours, probably due to a reduction in surface boundary layer turbulence. The sum of daily APC for each grass pollen season was highly correlated ( r = 0.79) with spring rainfall in Melbourne for that year, with about 60% of a declining linear trend across the study period being attributable to a reduction of meat cattle and sheep (and hence grazing land) in rural areas around Melbourne. Finally, all of the ten extreme pollen events (3 days or more with APC > 100 pollen grains m-3) during the study period were characterised by an average downward vertical wind anomaly in the surface boundary layer over Melbourne. Together these findings form a basis for a fine resolution atmospheric general circulation model for grass pollen in Melbourne's air that can be used to predict daily (and hourly) APC. This information will be useful to those sectors of Melbourne's population that suffer from allergic problems.

  14. Development and characterization of a recombinant, hypoallergenic, peptide-based vaccine for grass pollen allergy

    PubMed Central

    Focke-Tejkl, Margarete; Weber, Milena; Niespodziana, Katarzyna; Neubauer, Angela; Huber, Hans; Henning, Rainer; Stegfellner, Gottfried; Maderegger, Bernhard; Hauer, Martina; Stolz, Frank; Niederberger, Verena; Marth, Katharina; Eckl-Dorna, Julia; Weiss, Richard; Thalhamer, Josef; Blatt, Katharina; Valent, Peter; Valenta, Rudolf

    2015-01-01

    Background Grass pollen is one of the most important sources of respiratory allergies worldwide. Objective This study describes the development of a grass pollen allergy vaccine based on recombinant hypoallergenic derivatives of the major timothy grass pollen allergens Phl p 1, Phl p 2, Phl p 5, and Phl p 6 by using a peptide-carrier approach. Methods Fusion proteins consisting of nonallergenic peptides from the 4 major timothy grass pollen allergens and the PreS protein from hepatitis B virus as a carrier were expressed in Escherichia coli and purified by means of chromatography. Recombinant PreS fusion proteins were tested for allergenic activity and T-cell activation by means of IgE serology, basophil activation testing, T-cell proliferation assays, and xMAP Luminex technology in patients with grass pollen allergy. Rabbits were immunized with PreS fusion proteins to characterize their immunogenicity. Results Ten hypoallergenic PreS fusion proteins were constructed, expressed, and purified. According to immunogenicity and induction of allergen-specific blocking IgG antibodies, 4 hypoallergenic fusion proteins (BM321, BM322, BM325, and BM326) representing Phl p 1, Phl p 2, Phl p 5, and Phl p 6 were included as components in the vaccine termed BM32. BM321, BM322, BM325, and BM326 showed almost completely abolished allergenic activity and induced significantly reduced T-cell proliferation and release of proinflammatory cytokines in patients' PBMCs compared with grass pollen allergens. On immunization, they induced allergen-specific IgG antibodies, which inhibited patients' IgE binding to all 4 major allergens of grass pollen, as well as allergen-induced basophil activation. Conclusion A recombinant hypoallergenic grass pollen allergy vaccine (BM32) consisting of 4 recombinant PreS-fused grass pollen allergen peptides was developed for safe immunotherapy of grass pollen allergy. PMID:25441634

  15. 9 CFR 72.19 - Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... straw, grass, litter from quarantined area; prohibited until disinfected. 72.19 Section 72.19 Animals... Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until disinfected. Pine straw, grass, or similar litter collected from tick-infested pastures, ranges, or premises...

  16. 9 CFR 72.19 - Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... straw, grass, litter from quarantined area; prohibited until disinfected. 72.19 Section 72.19 Animals... Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until disinfected. Pine straw, grass, or similar litter collected from tick-infested pastures, ranges, or premises...

  17. 9 CFR 72.19 - Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... straw, grass, litter from quarantined area; prohibited until disinfected. 72.19 Section 72.19 Animals... Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until disinfected. Pine straw, grass, or similar litter collected from tick-infested pastures, ranges, or premises...

  18. 9 CFR 72.19 - Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... straw, grass, litter from quarantined area; prohibited until disinfected. 72.19 Section 72.19 Animals... and use of pine straw, grass, litter from quarantined area; prohibited until disinfected. Pine straw, grass, or similar litter collected from tick-infested pastures, ranges, or premises may disseminate...

  19. 9 CFR 72.19 - Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... straw, grass, litter from quarantined area; prohibited until disinfected. 72.19 Section 72.19 Animals... Interstate shipments and use of pine straw, grass, litter from quarantined area; prohibited until disinfected. Pine straw, grass, or similar litter collected from tick-infested pastures, ranges, or premises...

  20. Analyzing rasters, vectors and time series using new Python interfaces in GRASS GIS 7

    NASA Astrophysics Data System (ADS)

    Petras, Vaclav; Petrasova, Anna; Chemin, Yann; Zambelli, Pietro; Landa, Martin; Gebbert, Sören; Neteler, Markus; Löwe, Peter

    2015-04-01

    GRASS GIS 7 is a free and open source GIS software developed and used by many scientists (Neteler et al., 2012). While some users of GRASS GIS prefer its graphical user interface, significant part of the scientific community takes advantage of various scripting and programing interfaces offered by GRASS GIS to develop new models and algorithms. Here we will present different interfaces added to GRASS GIS 7 and available in Python, a popular programming language and environment in geosciences. These Python interfaces are designed to satisfy the needs of scientists and programmers under various circumstances. PyGRASS (Zambelli et al., 2013) is a new object-oriented interface to GRASS GIS modules and libraries. The GRASS GIS libraries are implemented in C to ensure maximum performance and the PyGRASS interface provides an intuitive, pythonic access to their functionality. GRASS GIS Python scripting library is another way of accessing GRASS GIS modules. It combines the simplicity of Bash and the efficiency of the Python syntax. When full access to all low-level and advanced functions and structures from GRASS GIS library is required, Python programmers can use an interface based on the Python ctypes package. Ctypes interface provides complete, direct access to all functionality as it would be available to C programmers. GRASS GIS provides specialized Python library for managing and analyzing spatio-temporal data (Gebbert and Pebesma, 2014). The temporal library introduces space time datasets representing time series of raster, 3D raster or vector maps and allows users to combine various spatio-temporal operations including queries, aggregation, sampling or the analysis of spatio-temporal topology. We will also discuss the advantages of implementing scientific algorithm as a GRASS GIS module and we will show how to write such module in Python. To facilitate the development of the module, GRASS GIS provides a Python library for testing (Petras and Gebbert, 2014) which

  1. Photosynthesis in Grass Species Differing in Carbon Dioxide Fixation Pathways

    PubMed Central

    Morgan, Jack A.; Brown, R. Harold

    1979-01-01

    Thirty-three grass species were examined in two experiments in an attempt to locate plants with photosynthetic responses to O2, CO2 compensation concentrations, and leaf anatomy intermediate to those of C3 and C4 species. Species examined included seven from the Laxa group in the Panicum genus, one of which, P. milioides Nees ex Trin., has been reported earlier to have intermediate characteristics. The species with O2-sensitive photosynthesis typical of C3 plants showed more than 37% increase in apparent photosynthesis at 2% O2 compared to 21% O2 at 25 C and 335 microliters per liter CO2, whereas in Panicum milioides, P. schenckii Hack., and P. decipiens Nees ex Trin., members of the Laxa group of Panicum, increases ranged from 25 to 30%. The remainder of the species did not respond to O2. Species with O2 responses characteristic of C3 plants exhibited CO2 compensation concentrations of 44 microliters per liter or higher at 21% O2 and 25 to 27.5 C and species characterized as O2-insensitive had values of microliters per liter or less. The CO2 compensation concentration (Г) values of P. milioides, P. schenckii, and P. decipiens ranged from 10.3 to 23.3 microliters per liter. Other species of the Laxa group of Panicum exhibited O2 response and Г values of either C3 (P. laxum Sw., P. hylaeicum Mez., and P. rivulare Trin.) or C4 (P. prionitis Griseb.) plants. Leaves of species with O2 response and CO2 compensation values typical of C3 plants had poorly developed or nearly empty bundle sheath cells, and much larger distances and mesophyll cell numbers between veins than did the O2-insensitive ones. Vein spacings in P. milioides, P. schenckii, and P. decipiens ranged from 0.18 to 0.28 millimeter and mesophyll cell number between veins from 5.2 to 7.8. While these vein spacings are closer than those of most C3 grasses, two O2-sensitive species of Dactylis had vein spacings similar to these Panicums and veins in Glyceria striata, another O2-sensitive plant, were

  2. California annual grass invaders: the drivers or passengers of change?

    PubMed Central

    HilleRisLambers, Janneke; Yelenik, Stephanie G; Colman, Benjamin P; Levine, Jonathan M

    2010-01-01

    The dominance of invasive species is often assumed to reflect their competitive superiority over displaced native species. However, invasive species may be abundant because of their greater tolerance to anthropogenic impacts accompanying their introduction. Thus, invasive species can either be the drivers or passengers of change. We distinguish between these two possibilities in California grasslands currently dominated by Mediterranean annuals (exotics) and subjected to livestock grazing since European settlement. We focused on native annual grasses and forbs, an understudied species-rich component of the California flora, and Mediterranean annual grasses, currently dominant and among the first non-native plants introduced to the area. We established a field experiment with fenced and unfenced blocks in a cattle pasture. We measured concentrations of limiting resources (nitrogen, phosphorus, light and soil moisture) in monoculture plots as an index of competitive ability (i.e. R*). We then quantified grazing impacts on biomass and seed production in grazed vs. ungrazed monoculture plots. Finally, we measured biomass and seed production of each species competing in mixture plots, in the presence and absence of grazers. We found that native and exotic species did not differ in R* indices of competitive ability, i.e. concentrations of limiting resources in ungrazed native monoculture plots did not differ from concentrations in ungrazed exotic monoculture plots. By contrast, exotic annuals suffered less from grazing than native annuals, perhaps reflecting their longer evolutionary history with cattle grazing. Consistent with these results, native and exotic annuals were equally abundant in ungrazed mixtures, but exotic species overwhelmingly dominated grazed mixtures. Species able to draw down nitrogen and light to lower levels in monocultures (i.e. those with lower R* values) dominated biomass and seeds in mixed plots without grazers. However, R* did not predict the

  3. Evolutionary history of chloridoid grasses estimated from 122 nuclear loci.

    PubMed

    Fisher, Amanda E; Hasenstab, Kristen M; Bell, Hester L; Blaine, Ellen; Ingram, Amanda L; Columbus, J Travis

    2016-12-01

    Chloridoideae (chloridoid grasses) are a subfamily of ca. 1700 species with high diversity in arid habitats. Until now, their evolutionary relationships have primarily been studied with DNA sequences from the chloroplast, a maternally inherited organelle. Next-generation sequencing is able to efficiently recover large numbers of nuclear loci that can then be used to estimate the species phylogeny based upon bi-parentally inherited data. We sought to test our chloroplast-based hypotheses of relationships among chloridoid species with 122 nuclear loci generated through targeted-enrichment next-generation sequencing, sometimes referred to as hyb-seq. We targeted putative single-copy housekeeping genes, as well as genes that have been implicated in traits characteristic of, or particularly labile in, chloridoids: e.g., drought and salt tolerance. We recovered ca. 70% of the targeted loci (122 of 177 loci) in all 47 species sequenced using hyb-seq. We then analyzed the nuclear loci with Bayesian and coalescent methods and the resulting phylogeny resolves relationships between the four chloridoid tribes. Several novel findings with this data were: the sister lineage to Chloridoideae is unresolved; Centropodia+Ellisochloa are excluded from Chloridoideae in phylogenetic estimates using a coalescent model; Sporobolus subtilis is more closely related to Eragrostis than to other species of Sporobolus; and Tragus is more closely related to Chloris and relatives than to a lineage of mainly New World species. Relationships in Cynodonteae in the nuclear phylogeny are quite different from chloroplast estimates, but were not robust to changes in the method of phylogenetic analysis. We tested the data signal with several partition schemes, a concatenation analysis, and tests of alternative hypotheses to assess our confidence in this new, nuclear estimate of evolutionary relationships. Our work provides markers and a framework for additional phylogenetic studies that sample more

  4. Convergent and contingent community responses to grass source and dominance during prairie restoration across a longitudinal gradient.

    PubMed

    Klopf, Ryan P; Baer, Sara G; Gibson, David J

    2014-02-01

    Restoring prairie on formerly cultivated land begins by selecting propagule seed sources and the diversity of species to reintroduce. This study examined the effects of dominant grass propagule source (cultivar vs. non-cultivar) and sown propagule diversity (grass:forb sowing ratio) on plant community structure. Two field experiments were established in Kansas and Illinois consisting of identical split plot designs. Dominant grass source was assigned as the whole-plot factor, and sown dominance of grasses (five levels of seeded grass dominance) as the subplot factor. Species density, cover, and diversity were quantified for 5 years. The effect of dominant grass source on the cover of focal grasses, sown species, and volunteer species was contingent upon location, with variation between dominant grass sources observed exclusively in Kansas. Species density and diversity showed regionally convergent patterns in response to dominant grass source. Contrary to our hypotheses, total species density and diversity were not lower in the presence of grass cultivars, the grass source we had predicted would be more competitive. Sown grass dominance effects on the cover of the focal grass species were contingent upon location resulting from establishment corresponding better to the assigned treatments in Illinois. All other cover groups showed regionally convergent patterns, with lower cover of volunteers and higher cover of sown forbs, diversity, and species density in the lowest sown grass dominance treatment in both sites. Thus, decisions regarding the diversity of propagules to reintroduce had more consequence for plant community structure than cultivar or non-cultivar source of dominant grasses.

  5. From Water Dynamics to Rainfed Landscapes with GRASS GIS

    NASA Astrophysics Data System (ADS)

    Chemin, Yann; van Brakel, Martin; Johnston, Robyn; Curnow, Jayne

    2014-05-01

    Variability in water availability is a key determinant of risk and constraint to productivity in rainfed agricultural systems. Understanding the dynamics of water availability across both spatial and temporal scales is essential to managing water and optimize production. This research proposes to look at both the physical measurement of water availability and water user perceptions of landscapes and water availability. Evapotranspiration makes up about three quarters of the transiting water in a landscape, it is composed of evaporation (water bodies, soil) and transpiration, the vegetation biomass growing quantity. This work will develop a methodology for defining landscapes based on water dynamics to be used at the interface of WLE research. The GRASS GIS Imagery, Landscape and Temporal toolkits form the basis of the methodological development, from evapotranspiration modeling and landscape analysis to spatio-temporal analysis.

  6. High-value renewable energy from prairie grasses.

    PubMed

    McLaughlin, S B; de la Torre Ugarte, D G; Garten, C T; Lynd, L R; Sanderson, M A; Tolbert, V R; Wolf, D D

    2002-05-15

    Projected economic benefits of renewable energy derived from a native prairie grass, switchgrass, include nonmarket values that can reduce net fuel costs to near zero. At a farm gate price of $44.00/dry Mg, an agricultural sector model predicts higher profits for switchgrass than conventional crops on 16.9 million hectares (ha). Benefits would include an annual increase of $6 billion in net farm returns, a $1.86 billion reduction in government subsidies, and displacement of 44-159 Tg/year (1 Tg = 1012 g) of greenhouse gas emissions. Incorporating these values into the pricing structure for switchgrass bioenergy could accelerate commercialization and provide net benefits to the U.S. economy.

  7. Cercosporoid fungi (Mycosphaerellaceae) 3. Species on monocots (Poaceae, true grasses).

    PubMed

    Braun, Uwe; Crous, Pedro W; Nakashima, Chiharu

    2015-06-01

    The third part of a series of monographic treatments of cercosporoid fungi (formerly Cercospora s. lat., Mycosphaerellaceae, Ascomycota) continues with a treatment of taxa on monocots (Liliopsida; Equisetopsida, Magnoliidae, Lilianae), covering asexual and holomorph species with mycosphaerella-like sexual morphs on true grasses (Poaceae), which were excluded from the second part. The species concerned are keyed out, alphabetically listed, described, illustrated and supplemented by references to previously published descriptions, illustrations, and exsiccatae. A key to the recognised genera and a discussion of taxonomically relevant characters was published in the first part of this series. Several species are lecto- or neotypified. The following taxonomic novelties are introduced: Cercospora barretoana comb. nov., C. cymbopogonicola nom. nov., Cladosporium elymi comb. nov., Passalora agrostidicola sp. nov., P. brachyelytri comb. nov., and P. dichanthii-annulati comb. nov.

  8. High-value renewable energy from prairie grasses

    SciTech Connect

    McLaughlin Jr, Samuel B; De La Torre Ugarte, D.; Garten Jr, Charles T; Lynd, L.; Sanderson, M.; Tolbert, Virginia R; Wolf, D.

    2002-05-01

    Projected economic benefits of renewable energy derived from a native prairie grass, switchgrass, include nonmarket values that can reduce net fuel costs to near zero. At a farm gate price of $44.00/dry Mg, an agricultural sector model predicts higher profits for switchgrass than conventional crops on 16.9 million hectares (ha). Benefits would include an annual increase of $6 billion in net farm returns, a $1.86 billion reduction in government subsidies, and displacement of 44-159 Tg/year (1 Tg = 10{sup 12} g) of greenhouse gas emissions. Incorporating these values into the pricing structure for switchgrass bioenergy could accelerate commercialization and provide net benefits to the U.S. economy.

  9. Lathyrus sativus (grass pea) and its neurotoxin ODAP.

    PubMed

    Yan, Ze-Yi; Spencer, Peter S; Li, Zhi-Xiao; Liang, Yong-Min; Wang, Ya-Fu; Wang, Chun-Ying; Li, Fen-Min

    2006-01-01

    Lathyrus sativus (grass pea) is a high-yielding, drought-resistant legume consumed as a food in Northern India and neighboring countries as well as in Ethiopia. Its development into an important food legume, however, has been hindered by the presence of the neurotoxin - beta-N-oxalyl-L-alpha,beta-diaminopropionic acid (beta-ODAP) in seeds which, if consumed in large quantities for prolonged periods, can cause irreversible paralysis. Recently, some low-toxin lines have been developed that may prove safe for both animal and human foods. Cultivation of L. sativus should thus be considered in suitable regions because the demand for legume animal feed protein products is expected to increase. This paper addresses advances in understanding L. sativus from the perspective of its taxonomy, genetics, ecology, chemistry, nutrition, medicine, biology and for animal nutrition.

  10. C-isotope composition of fossil sedges and grasses

    NASA Astrophysics Data System (ADS)

    Kurschner, Wolfram M.

    2010-05-01

    C4 plants differ from C3 plants regarding their anatomy and their C-isotope composition. Both features can be used in the geological record to determine the presence of C4 plants. Yet, the evolution of the C4 pathway in the fossil record is enigmatic as palaeobotanical and geological evidence for C4 plants is sparse. The oldest structural evidence for Kranz anatomy has been found in Late Miocene permineralized grass leaf remains. But studies on the C-isotope composition of sedimentary organic matter indicate that abundant C4 biomass was present in N-America and Asia throughout the Miocene in expanding savannahs and grasslands. The success of C4 plants appears to be related also to an increasing seasonal aridity in the tropical climate belts and the co-evolution of grazers. However, C- isotope composition of palaeosols or vertebrate teeth only allows to estimate the abundance of C4 plant biomass in the vegetation or in the diet without further taxonomical specification which plant groups would have had C4 metabolism. In this contribution the first extensive C-isotope analysis of fossil seeds of sedges and a few grasses are presented. The age of the carpological material ranges from Late Eocene to Pliocene and was collected from several central European brown coal deposits. The 52 different taxa studied include several species of Carex, Cladiocarya, Eriopherum, Eleocharis, Scirpus, Sparganium. Most of them representing herbaceous elements of a (sub)tropical vegetation growing near the edge of a lake. The C-isotope composition of the fossil seeds varies between -30 and -23 o/oo indicating C3 photosynthesis. This first systematic inventory shows that C4 plants were absent in the European (sub)tropical brown coal forming wetland vegetation during the Tertiary. These preliminary data are in agreement with phylogenetic studies which predict the origin of C4 plants outside the European realm.

  11. Senescence, dormancy and tillering in perennial C4 grasses.

    PubMed

    Sarath, Gautam; Baird, Lisa M; Mitchell, Robert B

    2014-03-01

    Perennial, temperate, C4 grasses, such as switchgrass and miscanthus have been tabbed as sources of herbaceous biomass for the production of green fuels and chemicals based on a number of positive agronomic traits. Although there is important literature on the management of these species for biomass production on marginal lands, numerous aspects of their biology are as yet unexplored at the molecular level. Perenniality, a key agronomic trait, is a function of plant dormancy and winter survival of the below-ground parts of the plants. These include the crowns, rhizomes and meristems that will produce tillers. Maintaining meristem viability is critical for the continued survival of the plants. Plant tillers emerge from the dormant crown and rhizome meristems at the start of the growing period in the spring, progress through a phase of vegetative growth, followed by flowering and eventually undergo senescence. There is nutrient mobilization from the aerial portions of the plant to the crowns and rhizomes during tiller senescence. Signals arising from the shoots and from the environment can be expected to be integrated as the plants enter into dormancy. Plant senescence and dormancy have been well studied in several dicot species and offer a potential framework to understand these processes in temperate C4 perennial grasses. The availability of latitudinally adapted populations for switchgrass presents an opportunity to dissect molecular mechanisms that can impact senescence, dormancy and winter survival. Given the large increase in genomic and other resources for switchgrass, it is anticipated that projected molecular studies with switchgrass will have a broader impact on related species.

  12. Processing Uav and LIDAR Point Clouds in Grass GIS

    NASA Astrophysics Data System (ADS)

    Petras, V.; Petrasova, A.; Jeziorska, J.; Mitasova, H.

    2016-06-01

    Today's methods of acquiring Earth surface data, namely lidar and unmanned aerial vehicle (UAV) imagery, non-selectively collect or generate large amounts of points. Point clouds from different sources vary in their properties such as number of returns, density, or quality. We present a set of tools with applications for different types of points clouds obtained by a lidar scanner, structure from motion technique (SfM), and a low-cost 3D scanner. To take advantage of the vertical structure of multiple return lidar point clouds, we demonstrate tools to process them using 3D raster techniques which allow, for example, the development of custom vegetation classification methods. Dense point clouds obtained from UAV imagery, often containing redundant points, can be decimated using various techniques before further processing. We implemented and compared several decimation techniques in regard to their performance and the final digital surface model (DSM). Finally, we will describe the processing of a point cloud from a low-cost 3D scanner, namely Microsoft Kinect, and its application for interaction with physical models. All the presented tools are open source and integrated in GRASS GIS, a multi-purpose open source GIS with remote sensing capabilities. The tools integrate with other open source projects, specifically Point Data Abstraction Library (PDAL), Point Cloud Library (PCL), and OpenKinect libfreenect2 library to benefit from the open source point cloud ecosystem. The implementation in GRASS GIS ensures long term maintenance and reproducibility by the scientific community but also by the original authors themselves.

  13. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies.

    PubMed

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  14. Climate drives shifts in grass reproductive phenology across the western USA.

    PubMed

    Munson, Seth M; Long, A Lexine

    2017-03-01

    The capacity of grass species to alter their reproductive timing across space and through time can indicate their ability to cope with environmental variability and help predict their future performance under climate change. We determined the long-term (1895-2013) relationship between flowering times of grass species and climate in space and time using herbarium records across ecoregions of the western USA. There was widespread concordance of C3 grasses accelerating flowering time and general delays for C4 grasses with increasing mean annual temperature, with the largest changes for annuals and individuals occurring in more northerly, wetter ecoregions. Flowering time was delayed for most grass species with increasing mean annual precipitation across space, while phenology-precipitation relationships through time were more mixed. Our results suggest that the phenology of most grass species has the capacity to respond to increases in temperature and altered precipitation expected with climate change, but weak relationships for some species in time suggest that climate tracking via migration or adaptation may be required. Divergence in phenological responses among grass functional types, species, and ecoregions suggests that climate change will have unequal effects across the western USA.

  15. EVOLUTIONS OF A BLACK-GRASS POPULATION SUBMITTED TO DIVERSE CROP SYSTEMS.

    PubMed

    Henriet, F; Matrheeuws, L; Verbiest, M

    2014-01-01

    Black-grass is a common grass weed, widely spread in Northern Europe and also in Belgium. The first case of resistance in Belgium was reported by Eelen et al. (1996). Since then, monitoring showed that resistant black-grass was not confined to restricted areas anymore and that all usually effective modes of action could be subject to resistance issue (Henriet and Maréchal, 2009). There is no report that agrochemical companies will soon bring a new mode of action effective against grasses on the market, in a close future. It is therefore important to preserve the still effective actives by integrating them into global weeding strategies. A long-lasting trial was set up in order to study the evolution of a black-grass population when submitted to diverse crop systems. Several factors were studied such as rotation (quadri-annual-bisannual-monoculture winter wheat), sowing date (standard date or delayed), cultivation (inversion tillage or not) and herbicide treatments. During three years, each time winter wheat occurred in the rotation, each plot gets the same factorial combination (rotation excepted). In untreated plots, black-grass head counting's showed no differences between tillage or not and bisannual or quadri-annual rotation. On the other hand, number of black-grass heads was higher in standard sowing date and monoculture than in delayed sowing date and other rotations, respectively. The general efficacy of the herbicide treatments was decreasing over the years.

  16. The effect of seaweed Ecklonia maxima extract and mineral nitrogen on fodder grass chemical composition.

    PubMed

    Ciepiela, Grażyna Anna; Godlewska, Agnieszka; Jankowska, Jolanta

    2016-02-01

    The objective of this study was to determine the effect of the biostimulant Kelpak and different nitrogen rates on cellulose, hemicellulose and lignin contents as well as non-structural carbohydrates in orchard grass and Braun's festulolium. The experiment was a split-plot arrangement with three replicates. It was set up at the experimental facility of the University of Natural Sciences and Humanities, Siedlce, in late April 2009. The following factors were examined: biostimulant with the trade name Kelpak SL applied at 2 dm(3) ha(-1) and a control-no biostimulant; nitrogen application rates 50 and 150 kg ha(-1) and a control (0 kg ha(-1)); pure stands of grass species grown in monoculture--orchard grass (Dactylis glomerata), cv. Amila,-Braun's festulolium (Festulolium braunii), cv. Felopa. Kelpak significantly increased non-structural carbohydrates, and increasing nitrogen rates reduced the concentration of these components in plants. Increasing nitrogen rates significantly decreased cellulose, hemicellulose, lignin and non-structural carbohydrate contents. Compared with orchard grass, Braun's festulolium proved to be of a higher nutritional value due to lower cellulose, hemicellulose and lignin contents and more non-structural carbohydrates. The aforementioned contents in the grasses differed significantly depending on the cut. Most cellulose and non-structural carbohydrates were determined in second-cut grass whereas most hemicellulose and lignin in second-cut grass.

  17. Effects of triploid grass carp on aquatic plants, water quality, and public satisfaction in Washington State

    USGS Publications Warehouse

    Bonar, Scott A.; Bolding, B.; Divens, M.

    2002-01-01

    We investigated effects of triploid grass carp Ctenopharyngodon idella on aquatic macrophyte communities, water quality, and public satisfaction for 98 lakes and ponds in Washington State stocked with grass carp between 1990 and 1995. Grass carp had few noticeable effects on macrophyte communities until 19 months following stocking. After 19 months, submersed macrophytes were either completely eradicated (39% of the lakes) or not controlled (42% of the lakes) in most lakes. Intermediate control of submersed macrophytes occurred in 18% of lakes at a median stocking rate of 24 fish per vegetated surface acre. Most of the landowners interviewed (83%) were satisfied with the results of introducing grass carp. For sites where all submersed macrophytes were eradicated, average turbidity was higher (11 nephelometric turbidity units, NTU) than at sites where macrophytes were controlled to intermediate levels (4 NTU) or unaffected by grass carp grazing (5 NTU). Chlorophyll a was not significantly different between levels of macrophyte control; therefore, we concluded that most of this turbidity was abiotic and not algal. Triploid grass carp were a popular control option and effectively grazed most submersed macrophytes in Washington State. However, calculating stocking rates based on landowner estimates of aquatic plant coverage rarely resulted in intermediate levels of aquatic plant control. Additionally, the effects of particular stocking rates varied considerably. We recommend against using grass carp in Washington lakes where eradication of submersed vegetation cannot be tolerated.

  18. Production of sugarcane and tropical grasses as renewable energy source. Third annual report, 1979-1980

    SciTech Connect

    Not Available

    1980-01-01

    Research continued on tropical grasses from Saccharum and related genera as sources of intensively-propagated fiber and fermentable solids. Candidate screening for short-rotation grasses was expanded to include six sorghum x Sudan grass hybrids developed by the Dekalb Company. Sugacane and napier grass yield trends in year 3 include: (1) Increased yields with delay of harvest frequency; (2) lack of response to close spacing; (3) a superiority of napier grass over sugarcane when harvested at intervals of six months or less; and (4) a general superiority of the sugarcane variety NCo 310 over varieties PR 980 and PR 64-1791. Delayed tasseling of a wild, early-flowering S. spontaneum hybrid enabled three crosses to be made in December using commercial hybrids as female parents. Approximately 1000 seedlings were produced. The first field-scale minimum tillage experiment was completed. Sordan 77 produced 2.23 OD tons/acre/10 weeks, with winter growing conditions and a total moisture input of 4.75 inches. Mechanization trials included successful planting of napier grass with a sugarcane planter, and the mowing, solar-drying, and round--baling of napier grass aged three to six months. Production-cost and energy-balance studies were initiated during year 3 using first-ratoon data for intensively propagated sugarcane. Preliminary cost estimates for energy cane (sugarcane managed for total biomass rather than sucrose) were in the order of $25.46/OD ton, or about $1.70/mm Btus.

  19. Erosion risk assessment of controlled burning of grasses established on steep slopes

    NASA Astrophysics Data System (ADS)

    Gyasi-Agyei, Yeboah

    2006-02-01

    It is a standard practice to establish grasses on steep slopes (batters) of embankments and cuttings to minimise erosion problems. However, the increase in grass density (high biomass) on the steep slopes poses a greater risk of fire. Controlled burning is a common fuel hazard reduction program employed to minimise the fire risks. The increased risk of erosion on the steep slopes after controlled burning has received little attention if any. This paper assesses the erosion risks associated with controlled burning of grasses established on steep slopes. Grasses, with and without the aid of waste ballast rock mulch, were established on 10 m wide railway embankment batter experiment plots. Two-and-a-half years after the grass establishment, selected plots were controlled burned. Runoff and soil loss from the experimental plots were monitored throughout the 3½-year period of the experiment. After one year the grass cover on the burned plots has hardly exceeded 60%, far below the average pre-burn levels of about 80%. All treatments achieved an incredible soil loss reduction of over 95% (compared with the bare scenario) without controlled burning at the end of the 3½-year period. This percentage value was decreased numerically by 14 where controlled burning was implemented. Compared with the 100% grass cover treatment, runoff rates tripled while erosion rates increased by nine-fold for the waste ballast treatment, and 17-fold for the non-waste ballast treatment, during the first year following controlled burning.

  20. Complex interactions between a legume and two grasses in a subalpine meadow.

    PubMed

    Marty, Charles; Pornon, André; Escaravage, Nathalie; Winterton, Peter; Lamaze, Thierry

    2009-10-01

    Interactions between plants are a complex combination of positive and negative interactions, with the net outcome depending on environmental contexts. The more frequent association of Trifolium alpinum (legume) with Festuca eskia than with Nardus stricta (grasses) in many Pyrenean subalpine meadows suggests a differential ability to use nitrogen (N) derived from N(2) fixation. In the field, we investigated the interactions between the legume and grasses and, in the glasshouse, the transfer of (15)N from the legume to the grasses. In one grass-Trifolium mixture, the legume had a strong positive effect on the biomass and N content of the grass as compared to pure grass stands. When both grasses grew together with the legume, only Festuca benefited from the presence of Trifolium but, surprisingly, the benefit decreased with increasing Trifolium abundance. Leaf labeling experiments with (15)N-NH(4)(+) revealed a higher transfer of (15)N from Trifolium to Festuca than to Nardus, suggesting a more direct N pathway between the two species. This more direct pathway could prevent Nardus from benefiting from the legume N in the three-species mixtures. Thus, the positive interactions between N-fixers and nonfixers appear to be largely species-specific and to depend strongly on the species in the plant assemblage.

  1. Urban Rights-of-Way as Reservoirs for Tall-Grass Prairie Plants and Butterflies

    NASA Astrophysics Data System (ADS)

    Leston, Lionel; Koper, Nicola

    2016-03-01

    Urban rights-of-way may be potential reservoirs of tall-grass prairie plants and butterflies. To determine if this is true, in 2007-2008, we conducted vegetation surveys of species richness and cover, and butterfly surveys of species richness and abundance, along 52 transmission lines and four remnant prairies in Winnipeg, Manitoba. We detected many prairie plants and butterflies within transmission lines. Some unmowed and infrequently managed transmission lines had native plant species richness and total percent cover of native plants comparable to that of similar-sized remnant tall-grass prairies in the region. Although we did not find significant differences in overall native butterfly numbers or species richness between rights-of-way and remnant prairies, we found lower numbers of some prairie butterflies along frequently mowed rights-of-way than within remnant tall-grass prairies. We also observed higher butterfly species richness along sites with more native plant species. By reducing mowing and spraying and reintroducing tall-grass prairie plants, urban rights-of-way could serve as extensive reservoirs for tall-grass prairie plants and butterflies in urban landscapes. Eventually, managing urban rights-of-way as reservoirs for tall-grass prairie plants and animals could contribute to the restoration of tall-grass prairie in the North American Midwest.

  2. Identification of brome grass infestations in southwest Oklahoma using multi-temporal Landsat imagery

    NASA Astrophysics Data System (ADS)

    Yan, D.; de Beurs, K.

    2013-12-01

    The extensive infestation of brome grasses (Cheatgrass, Rye brome and Japanese brome) in southwest Oklahoma imposes negative impacts on local economy and ecosystem in terms of decreasing crop and forage production and increasing fire risk. Previously proposed methodologies on brome grass detection are found ill-suitable for southwest Oklahoma as a result of similar responses of background vegetation to inter-annual variability of rainfall. In this study, we aim to identify brome grass infestations by detecting senescent brome grasses using the 2011 Cultivated Land Cover Data Sets and the difference Normalized Difference Infrared Index (NDII) derived from multi-temporal Landsat imagery. Landsat imageries acquired on May 18th and June 10th 2013 by Operational Land Imager and Enhanced Thematic Mapper plus were used. The imagery acquisition dates correspond to the peak growth and senescent time of brome grasses, respectively. The difference NDII was calculated by subtracting the NDII image acquired in May from the June NDII image. Our hypotheses is that senescent brome grasses and crop/pasture fields harvested between the two image acquisition dates can be distinguished from background land cover classes because of their increases in NDII due to decreased water absorption by senescent vegetation in the shortwave infrared region. The Cultivated Land Cover Data Sets were used to further separate senescent brome grass patches from newly harvested crop/pasture fields. Ground truth data collected during field trips in June, July and August of 2013 were used to validate the detection results.

  3. Genetic variations of body weight and GCRV resistance in a random mating population of grass carp

    PubMed Central

    Huang, Rong; Sun, Jiaxian; Luo, Qing; He, Libo; Liao, Lanjie; Li, Yongming; Guo, Fuhua; Zhu, Zuoyan; Wang, Yaping

    2015-01-01

    The grass carp (Ctenopharyngodon idellus) is an important species in freshwater aquaculture both in China and on a global scale. Variety degeneration and frequent diseases have limited the further development of grass carp aquaculture. Thus, new and improved varieties are required. Here, we identified and assessed the body weight and disease resistance in a random mating population of 19 ♀ × 22 ♂ grass carp, which were derived from different water systems. In both the growth experimental group of 10,245 fish and grass carp reovirus (GCRV)-infected group with 10,000 fish, 78 full-sib families were statistically analyzed for body weight and GCRV resistance. The findings showed that body weight traits had low heritability (0.11 ± 0.04, 0.10 ± 0.03 and 0.12 ± 0.05), GCRV resistance traits had high heritability (0.63 ± 0.11); body weight was higher in 3 families, whereas GCRV resistance was significantly greater in 11 families. Our results confirmed that the natural germplasm resources of wild grass carp were genetically diverse. Breeding of GCRV resistant varieties of grass carp have better genetic basis. This study provides the basis for constructing basal populations for grass carp selective breeding, quantitative trait loci (QTL) and genome-wide association studies (GWAS) analysis. PMID:26439690

  4. Particle selectivity of sediment deposited over grass barriers and the effect of rainfall

    NASA Astrophysics Data System (ADS)

    Pan, Chengzhong; Ma, Lan; Wainwright, John

    2016-10-01

    Particle selectivity of the sediment deposited over vegetative barriers is of importance to predict sediment transport and particulate pollutant load into surface waters. Grassed barriers with 20-90% covers at 15° slope were subjected to silt-laden inflows in the presence and absence of simulated rainfalls to investigate the sediment deposition processes. The results show that regrass of steep croplands can effectively trap eroded sediment from upslope, and the rowed grass barriers can strengthen sediment deposition. The deposition order of sediment particle sizes (μm) follows (>50) > (25-50) > (10-25) = (<2) > (2-10), and the particle selectivity weakens with increasing grass covers. Clay particles had a similar deposition efficiency to overall sediment, implying the effectiveness of regrass in controlling soil nutrient loss. The contribution of grass to total overland flow resistance is almost equivalent to the percentage of grass cover. For steep grassed slopes, raindrop impact significantly decreases sediment deposition, but limitedly affects particle selectivity of deposited sediment and overland flow hydraulics. Both raindrop kinetic energy and stream power available for surface soil contribute to sediment deposition in net deposition areas of grass barriers. These imply that rainfall effect on sediment delivery over vegetated barriers derives from the additional raindrop energy, rather than the variation in runoff hydraulics. These results can help to clarify the effect of raindrop impact on sediment transport and to evaluate the benefit of revegetation in decreasing sediment yield and its particulate nutrient load into surface waters.

  5. Climate drives shifts in grass reproductive phenology across the western USA

    USGS Publications Warehouse

    Munson, Seth M.; Long, A. Lexine

    2016-01-01

    The capacity of grass species to alter their reproductive timing across space and through time can indicate their ability to cope with environmental variability and help predict their future performance under climate change.We determined the long-term (1895–2013) relationship between flowering times of grass species and climate in space and time using herbarium records across ecoregions of the western USA.There was widespread concordance of C3 grasses accelerating flowering time and general delays for C4 grasses with increasing mean annual temperature, with the largest changes for annuals and individuals occurring in more northerly, wetter ecoregions. Flowering time was delayed for most grass species with increasing mean annual precipitation across space, while phenology–precipitation relationships through time were more mixed.Our results suggest that the phenology of most grass species has the capacity to respond to increases in temperature and altered precipitation expected with climate change, but weak relationships for some species in time suggest that climate tracking via migration or adaptation may be required. Divergence in phenological responses among grass functional types, species, and ecoregions suggests that climate change will have unequal effects across the western USA.

  6. Comparative assessment of the phytomeliorative efficiency of perennial grasses on chernozems in the transural part of Bashkortostan

    NASA Astrophysics Data System (ADS)

    Khasanova, R. F.; Suyundukov, Ya. T.; Suyundukova, M. B.

    2010-01-01

    The phytomeliorative efficiency of different groups of perennial herbs was studied. The agrophysical properties of soils under natural grasses (the feather grasses Stipa pennata, S. zalesskii, and S. Lessingiana; the fescue grass Festuca pseudovina; and quack grass), sawn herbs (awnless brome, crested wheat grass, purple alfalfa, the holy clover Onobrychis sibirica, the galega Galega orientalis, and yellow sweet clover), and cereal crops (winter rye and spring wheat) were compared. The formation of the aboveground and underground phytomass and the influence of phytomeliorative herbs on the aggregate state of leached, ordinary, and southern chernozems in the Transural part of Bashkortostan were analyzed.

  7. Fungal endophytes of native grasses decrease insect herbivore preference and performance.

    PubMed

    Crawford, Kerri M; Land, John M; Rudgers, Jennifer A

    2010-10-01

    Endophytic fungal symbionts of grasses are well known for their protective benefit of herbivory reduction. However, the majority of studies on endophyte-grass symbioses have been conducted on economically important, agricultural species-particularly tall fescue (Lolium arundinaceum) and perennial ryegrass (Lolium perenne)-raising the hypothesis that strong benefits are the product of artificial selection. We examined whether fungal endophytes found in natural populations of native grass species deterred insect herbivores. By testing several native grass-endophyte symbiota, we examined phylogenetic signals in the effects of endophytes on insects and compared the relative importance of herbivore and symbiotum identity in the outcome of the interactions. Preference was assessed using three herbivore species [Spodoptera frugiperda (Lepidoptera), Schistocerca americana (Orthoptera), Rhopalosiphum padi (Hemiptera)] and ten native symbiota, which spanned seven grass genera. We also assessed herbivore performance in a no choice experiment for five native symbiota against S. frugiperda. We compared greenhouse and laboratory trials with natural levels of herbivory measured in experimental field populations. In all cases, we included the agronomic grass species, L. arundinaceum, to compare with results from the native grasses. Both in the field and in experimental trials, herbivores showed a significant preference for endophyte-free plant material for the majority of native grasses, with up to three times lower herbivory for endophyte-symbiotic plants; however, the degree of response depended on the identity of the herbivore species. Endophyte presence also significantly reduced performance of S. frugiperda for the majority of grass species. In contrast, the endophyte in L. arundinaceum had few significant anti-herbivore effects, except for a reduction in herbivory at one of two field sites. Our results demonstrate that the mechanisms by which native symbionts deter

  8. Regional and seasonal variation in airborne grass pollen levels between cities of Australia and New Zealand.

    PubMed

    Medek, Danielle E; Beggs, Paul J; Erbas, Bircan; Jaggard, Alison K; Campbell, Bradley C; Vicendese, Don; Johnston, Fay H; Godwin, Ian; Huete, Alfredo R; Green, Brett J; Burton, Pamela K; Bowman, David M J S; Newnham, Rewi M; Katelaris, Constance H; Haberle, Simon G; Newbigin, Ed; Davies, Janet M

    Although grass pollen is widely regarded as the major outdoor aeroallergen source in Australia and New Zealand (NZ), no assemblage of airborne pollen data for the region has been previously compiled. Grass pollen count data collected at 14 urban sites in Australia and NZ over periods ranging from 1 to 17 years were acquired, assembled and compared, revealing considerable spatiotemporal variability. Although direct comparison between these data is problematic due to methodological differences between monitoring sites, the following patterns are apparent. Grass pollen seasons tended to have more than one peak from tropics to latitudes of 37°S and single peaks at sites south of this latitude. A longer grass pollen season was therefore found at sites below 37°S, driven by later seasonal end dates for grass growth and flowering. Daily pollen counts increased with latitude; subtropical regions had seasons of both high intensity and long duration. At higher latitude sites, the single springtime grass pollen peak is potentially due to a cooler growing season and a predominance of pollen from C3 grasses. The multiple peaks at lower latitude sites may be due to a warmer season and the predominance of pollen from C4 grasses. Prevalence and duration of seasonal allergies may reflect the differing pollen seasons across Australia and NZ. It must be emphasized that these findings are tentative due to limitations in the available data, reinforcing the need to implement standardized pollen-monitoring methods across Australasia. Furthermore, spatiotemporal differences in grass pollen counts indicate that local, current, standardized pollen monitoring would assist with the management of pollen allergen exposure for patients at risk of allergic rhinitis and asthma.

  9. Temperature and functional traits influence differences in nitrogen uptake capacity between native and invasive grasses.

    PubMed

    Leffler, A Joshua; James, Jeremy J; Monaco, Thomas A

    2013-01-01

    Performance differences between native and exotic invasive plants are often considered static, but invasive grasses may achieve growth advantages in western North America shrublands and steppe under only optimal growing conditions. We examine differences in N uptake and several morphological variables that influence uptake at temperatures between 5 and 25 °C. We contrast two native perennial grasses in western North America: Elymus elymoides and Pseudoroegneria spicata; two invasive annual grasses: Bromus tectorum and Taeniatherum caput-medusae; and one highly selected non-native perennial grass: Agropyron cristatum. The influence of temperature on N uptake is poorly characterized, yet these invasive annual grasses are known to germinate in warm soils in the autumn, and both experience cool soils during the short growing season following snowmelt in the spring. To further explore the influence of temperature on the correlation between morphological variables and N uptake, our data are applied to a previously published path model and one proposed here. Differences in N uptake between native and invasive grasses were small at the lowest temperature, but were large at the highest temperature. At lower temperatures, uptake of N by annuals and perennials was correlated with leaf N and mass. At higher temperatures, uptake by annuals was correlated only with these leaf traits, but uptake by perennials was correlated with these leaf traits as well as root N and mass. Consequently, our results imply that annual grasses face fewer morphological constraints on N uptake than perennial grasses, and annual grasses may gain further advantage in warmer temperature conditions or during more frequent warm periods.

  10. Excreting and non-excreting grasses exhibit different salt resistance strategies

    PubMed Central

    Moinuddin, Muhammad; Gulzar, Salman; Ahmed, Muhammad Zaheer; Gul, Bilquees; Koyro, Hans-Werner; Khan, Muhammad Ajmal

    2014-01-01

    The combination of traits that makes a plant successful under saline conditions varies with the type of plant and its interaction with the environmental conditions. Knowledge about the contribution of these traits towards salt resistance in grasses has great potential for improving the salt resistance of conventional crops. We attempted to identify differential adaptive response patterns of salt-excreting versus non-excreting grasses. More specifically, we studied the growth, osmotic, ionic and nutrient (carbon/nitrogen) relations of two salt-excreting (Aeluropus lagopoides and Sporobolus tremulus) and two non-excreting (Paspalum paspalodes and Paspalidium geminatum) perennial C4 grasses under non-saline and saline (0, 200 and 400 mM NaCl) conditions. Growth and relative growth rate decreased under saline conditions in the order P. geminatum > S. tremulus = A. lagopoides > P. paspalodes. The root-to-shoot biomass allocation was unaffected in salt-excreting grasses, increased in P. paspalodes but decreased in P. geminatum. Salt-excreting grasses had a higher shoot/root Na+ ratio than non-excreting grasses. K+, Ca2+ and Mg2+ homoeostasis remained undisturbed among test grasses possibly through improved ion selectivity with rising substrate salinity. Salt-excreting grasses increased leaf succulence, decreased ψs and xylem pressure potential, and accumulated proline and glycinebetaine with increasing salinity. Higher salt resistance of P. paspalodes could be attributed to lower Na+ uptake, higher nitrogen-use efficiency and higher water-use efficiency among the test species. However, P. geminatum was unable to cope with salt-induced physiological drought. More information is required to adequately document the differential strategies of salt resistance in salt-excreting and non-excreting grasses. PMID:24996428

  11. Regional and seasonal variation in airborne grass pollen levels between cities of Australia and New Zealand

    PubMed Central

    Beggs, Paul J.; Erbas, Bircan; Jaggard, Alison K.; Campbell, Bradley C.; Vicendese, Don; Johnston, Fay H.; Godwin, Ian; Huete, Alfredo R.; Green, Brett J.; Burton, Pamela K.; Bowman, David M. J. S.; Newnham, Rewi M.; Katelaris, Constance H.; Haberle, Simon G.; Newbigin, Ed; Davies, Janet M.

    2016-01-01

    Although grass pollen is widely regarded as the major outdoor aeroallergen source in Australia and New Zealand (NZ), no assemblage of airborne pollen data for the region has been previously compiled. Grass pollen count data collected at 14 urban sites in Australia and NZ over periods ranging from 1 to 17 years were acquired, assembled and compared, revealing considerable spatiotemporal variability. Although direct comparison between these data is problematic due to methodological differences between monitoring sites, the following patterns are apparent. Grass pollen seasons tended to have more than one peak from tropics to latitudes of 37°S and single peaks at sites south of this latitude. A longer grass pollen season was therefore found at sites below 37°S, driven by later seasonal end dates for grass growth and flowering. Daily pollen counts increased with latitude; subtropical regions had seasons of both high intensity and long duration. At higher latitude sites, the single springtime grass pollen peak is potentially due to a cooler growing season and a predominance of pollen from C3 grasses. The multiple peaks at lower latitude sites may be due to a warmer season and the predominance of pollen from C4 grasses. Prevalence and duration of seasonal allergies may reflect the differing pollen seasons across Australia and NZ. It must be emphasized that these findings are tentative due to limitations in the available data, reinforcing the need to implement standardized pollen-monitoring methods across Australasia. Furthermore, spatiotemporal differences in grass pollen counts indicate that local, current, standardized pollen monitoring would assist with the management of pollen allergen exposure for patients at risk of allergic rhinitis and asthma. PMID:27069303

  12. Allergen Microarray Indicates Pooideae Sensitization in Brazilian Grass Pollen Allergic Patients

    PubMed Central

    Moreira, Priscila Ferreira de Sousa; Gangl, Katharina; Vieira, Francisco de Assis Machado; Ynoue, Leandro Hideki; Linhart, Birgit; Flicker, Sabine; Fiebig, Helmut; Swoboda, Ines; Focke-Tejkl, Margarete; Taketomi, Ernesto Akio; Valenta, Rudolf; Niederberger, Verena

    2015-01-01

    Background Grass pollen, in particular from Lolium multiflorum is a major allergen source in temperate climate zones of Southern Brazil. The IgE sensitization profile of Brazilian grass pollen allergic patients to individual allergen molecules has not been analyzed yet. Objective To analyze the IgE sensitization profile of a Brazilian grass pollen allergic population using individual allergen molecules. Methods We analyzed sera from 78 grass pollen allergic patients for the presence of IgE antibodies specific for 103 purified micro-arrayed natural and recombinant allergens by chip technology. IgE-ELISA inhibition experiments with Lolium multiflorum, Phleum pratense extracts and a recombinant fusion protein consisting of Phl p 1, Phl p 2, Phl p 5 and Phl p 6 were performed to investigate cross-reactivities. Results Within the Brazilian grass pollen allergic patients, the most frequently recognized allergens were Phl p 1 (95%), Phl p 5 (82%), Phl p 2 (76%) followed by Phl p 4 (64%), Phl p 6 (45%), Phl p 11 (18%) and Phl p 12 (18%). Most patients were sensitized only to grass pollen allergens but not to allergens from other sources. A high degree of IgE cross-reactivity between Phleum pratense, Lolium multiflorum and the recombinant timothy grass fusion protein was found. Conclusions Component-resolved analysis of sera from Brazilian grass pollen allergic patients reveals an IgE recognition profile compatible with a typical Pooideae sensitization. The high degree of cross-reactivity between Phleum pratense and Lolium multiflorum allergens suggests that diagnosis and immunotherapy can be achieved with timothy grass pollen allergens in the studied population. PMID:26067084

  13. Comparison of in-shoe foot loading patterns on natural grass and synthetic turf.

    PubMed

    Ford, Kevin R; Manson, Neil A; Evans, Blake J; Myer, Gregory D; Gwin, Richelle C; Heidt, Robert S; Hewett, Timothy E

    2006-12-01

    Synthetic playing surfaces with rubber or sand infill are now used on many athletic fields such as soccer, football and rugby. Although these surfaces may come closer to the mechanical characteristics of a true grass playing surface than the older turf designs, their potential effects on lower extremity biomechanics and related injury rates necessitate further study. The purpose of this study was to examine the effects of two surfaces (natural grass versus turf) on in-shoe foot loading patterns during cutting. Seventeen male football players were tested on a slalom course. An in-shoe pressure distribution measurement insole was used in the right shoe (14 stud, molded cleat) of each athlete. Individual cutting steps were extracted from each slalom trial and peak pressure and relative load calculated in nine distinct plantar regions of the foot. The turf condition had significantly higher peak pressures within the central forefoot (turf: 646.6+/-172.6 kPa, grass: 533.3+/-143.4 kPa, P=0.017) and lesser toes (turf: 429.3+/-200.9 kPa, grass: 348.1+/-119.0 kPa, P=0.043) compared to grass. In contrast, the relative load within the medial forefoot (turf: 27.2+/-5.3%, grass: 30.2+/-6.6%, P=0.031) and lateral midfoot (turf: 3.4+/-1.8%, grass: 4.1+/-2.3%, P=0.029) were higher during the grass condition. No differences between the grass and turf were found in maximal effort sprint times performed prior to the testing trials. This study demonstrates that playing surface significantly affects plantar loading during sport related activities. Further epidemiological investigation is warranted to determine the effects of playing surfaces on sport specific injury mechanisms.

  14. First direct confirmation of grass carp spawning in a Great Lakes tributary

    USGS Publications Warehouse

    Embke, Holly S.; Kocovsky, Patrick M.; Richter, Catherine A.; Pritt, Jeremy J.; Christine M. Mayer,; Qian, Song

    2016-01-01

    Grass carp (Ctenopharyngodon idella), an invasive species of Asian carp, has been stocked for many decades in the United States for vegetation control. Adult individuals have been found in all of the Great Lakes except Lake Superior, but no self-sustaining populations have yet been identified in Great Lakes tributaries. In 2012, a commercial fisherman caught four juvenile diploid grass carp in the Sandusky River, a major tributary to Lake Erie. Otolith microchemistry and the capture location of these fish permitted the conclusion that they were most likely produced in the Sandusky River. Due to this finding, we sampled ichthyoplankton using paired bongo net tows and larval light traps during June–August of 2014 and 2015 to determine if grass carp are spawning in the Sandusky River. From the samples collected in 2015, we identified and staged eight eggs that were morphologically consistent with grass carp. Five eggs were confirmed as grass carp using quantitative Polymerase Chain Reaction for a grass carp-specific marker, while the remaining three were retained for future analysis. Our finding confirms that grass carp are naturally spawning in this Great Lakes tributary. All eggs were collected during high-flow events, either on the day of peak flow or 1–2 days following peak flow, supporting an earlier suggestion that high flow conditions favor grass carp spawning. The next principal goal is to identify the spawning and hatch location(s) for the Sandusky River. Predicting locations and conditions where grass carp spawning is most probable may aid targeted management efforts.

  15. Ensiling and hydrothermal pretreatment of grass: consequences for enzymatic biomass conversion and total monosaccharide yields

    PubMed Central

    2014-01-01

    Background Ensiling may act as a pretreatment of fresh grass biomass and increase the enzymatic conversion of structural carbohydrates to fermentable sugars. However, ensiling does not provide sufficient severity to be a standalone pretreatment method. Here, ensiling of grass is combined with hydrothermal treatment (HTT) with the aim of improving the enzymatic biomass convertibility and decrease the required temperature of the HTT. Results Grass silage (Festulolium Hykor) was hydrothermally treated at temperatures of 170, 180, and 190°C for 10 minutes. Relative to HTT treated dry grass, ensiling increased the solubilization of dry matter (DM) during HTT and gave increased glucan content, but lower lignin in the insoluble fiber fraction. Ensiling improved glucose yields in the enzymatic hydrolysis of the washed solid fiber fraction at the lower HTT temperatures. At 170°C glucose yield improved from 17 to 24 (w/w)% (45 to 57% cellulose convertibility), and at 180°C glucose yield improved from 22 to 29 (w/w)% (54 to 69% cellulose convertibility). Direct HTT of grass at 190°C gave the same high glucose yield as for grass silage (35 (w/w)% (77% cellulose convertibility)) and improved xylan yields (27% xylan convertibility). The effect of ensiling of grass prior to HTT improved the enzymatic conversion of cellulose for HTT at 170 and 180°C, but the increased glucose release did not make up for the loss of water soluble carbohydrates (WSC) during ensiling. Overall, sugar yields (C6 + C5) were similar for HTT of grass and grass silage at both 170 and 180°C, but at 190°C the overall sugar yield was better for HTT of dry grass. Conclusions This study unequivocally establishes that ensiling of grass as a biomass pretreatment method comes with a loss of WSC. The loss of WSC by ensiling is not necessarily compensated for by providing a lower temperature requirement for HTT for high enzymatic monosaccharide release. However, ensiling can be an advantageous storage

  16. Degradation of softwood, hardwood, and grass lignocelluloses by two Steptomyces strains

    SciTech Connect

    Antai, S.P.; Crawford, D.L.

    1981-08-01

    Two Streptomyces strains, S. viridosporus T7A and S. setonii 75Vi2, were grown on softwood, hardwood, and grass lignocelluloses, and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss over time. Results showed that both Streptomyces strains substantially degraded both the lignin and the carbohydrate components of each lignocellulose; however, these actinomycetes were more efficient decomposers of grass lignocelluloses than of hardwood or softwood lignocelluloses. In particular, these Streptomyces strains were more efficient decomposers of grass lignins than of hardwood or softwood lignins.

  17. Control of grass inflorescence form by the fine-tuning of meristem phase change.

    PubMed

    Kyozuka, Junko; Tokunaga, Hiroki; Yoshida, Akiko

    2014-02-01

    The grass inflorescence is interesting from the points of view of development and evolution. In the grass family, flowers are produced on small branches called spikelets. The recent isolation of regulators of spikelet meristem (SM) identity has shed new light on development and the evolution of the gene networks involved. The timing of SM specification is mediated by the combinatorial functions of these regulators, and determines the grass inflorescence form. Furthermore, tight links between meristem cell proliferation, maintenance of meristem indeterminacy, and suppression of the spikelet identity are being uncovered.

  18. Local versus landscape-scale effects of savanna trees on grasses

    USGS Publications Warehouse

    Riginos, C.; Grace, J.B.; Augustine, D.J.; Young, T.P.

    2009-01-01

    1. Savanna ecosystems - defined by the coexistence of trees and grasses - cover more than one-fifth the world's land surface and harbour most of the world's rangelands, livestock and large mammal diversity. Savanna trees can have a variety of effects on grasses, with consequences for the wild and domestic herbivores that depend on them. 2.Studies of these effects have focused on two different spatial scales. At the scale of individual trees, many studies have shown net positive effects of trees on sub-canopy grass nutrient concentrations and biomass. At the landscape scale, other studies have shown negative effects of high tree densities on grass productivity. These disparate results have led to different conclusions about the effects of trees on forage quality and ungulate nutrition in savannas. 3.We integrate these approaches by examining the effects of trees on grasses at both spatial scales and across a range of landscape-scale tree densities. 4.We quantified grass biomass, species composition and nutrient concentrations in these different contexts in an Acacia drepanolobium savanna in Laikipia, Kenya. Individual trees had positive effects on grass biomass, most likely because trees enrich soil nitrogen. Grass leaf phosphorus in sub-canopy areas, however, was depressed. The effects of individual trees could explain the effects of increasing landscape-scale tree cover for the biomass of only two of the four dominant grass species. 5.The negative effects of trees on grass and soil phosphorus, combined with depressed grass productivity in areas of high tree cover, suggest that ungulate nutrition may be compromised in areas with many trees. 6.Synthesis. We conclude that few, isolated trees may have positive local effects on savanna grasses and forage, but in areas of high tree density the negative landscape-scale effects of trees are likely to outweigh these positive effects. In savannas and other patchy landscapes, attempts to predict the consequences of changes

  19. Foraminifera and the ecology of sea grass communities since the late Cretaceous

    NASA Astrophysics Data System (ADS)

    Hart, Malcolm; Smart, Christopher; Jagt, John

    2016-04-01

    Sea grasses are marine angiosperms (plants) that, in the late Cretaceous, migrated from the land into shallow-water marine environments. They represent a distinct, but fragile, marine habitat and sea grass meadows are often regarded as biodiversity hot-spots with a range of species (including fish, sea horses and cuttlefish) using them as nurseries for their young. Foraminifera are often found associated with sea grass meadows, with the associated taxa reflecting both the environment and palaeolatitude. In the tropics and sub-tropics, miliolid foraminifera dominate (e.g., Peneroplis spp.) as do large discoidal taxa such as Marginopora and Calcarina. In temperate to cool latitudes the assemblage changes to one dominated by smaller benthic taxa, including Elphidium spp. One taxon, Elphidium crispum, is geotropic and is often found - in the summer months - to crowd the fronds of the sea grass. In the Gulpen and Maastricht formations of the Maastricht area (The Netherlands and Belgium) sea grass fossils (both fronds and rhizomes) have been recorded in association with assemblages of both larger and smaller benthic foraminifera (Hart et al., 2016). Some of the large discoidal forms (e.g., Omphalocyclus and Orbitoides/Lepidorbitoides) and the distinctive Siderolites are associated with these sea grass fossils and are suggestive of the modern sea grass communities of sub-tropical areas. While earlier records were of relatively isolated sea grasses, in September/October 2015 surfaces with abundant sea grasses were found that are suggestive of complete 'meadows'. Preservation of some silicified rhizomes indicates that silicification must have been very rapid, before any degradation or compaction of the delicate tissues. The presence of sea grass fossils and their associated benthic foraminifera is indicative of a clear, shallow-water seaway, with a maximum depth of 15-20 m. The reported variations in sea level during the latest Cretaceous cannot, therefore, have been very

  20. Breeding bird territory placement in riparian wet meadows in relation to invasive reed canary grass, Phalaris arundinacea

    USGS Publications Warehouse

    Kirsch, E.M.; Gray, B.R.; Fox, T.J.; Thogmartin, W.E.

    2007-01-01

    Invasive plants are a growing concern worldwide for conservation of native habitats. In endangered wet meadow habitat in the Upper Midwestern United States, reed canary grass (Phalaris arundinacea) is a recognized problem and its prevalence is more widespread than the better-known invasive wetland plant purple loosestrife (Lythrum salicaria). Although resource managers are concerned about the effect of reed canary grass on birds, this is the first study to report how common wet meadow birds use habitat in relation to reed canary grass cover and dominance. We examined three response variables: territory placement, size of territories, and numbers of territories per plot in relation to cover of reed canary grass. Territory locations for Sedge Wren (Cistothorus platensis) and Song Sparrow (Melospiza melodia) were positively associated with reed canary grass cover, while those for Common Yellowthroat (Geothlypis trichas) were not. Only Swamp Sparrow (M. georgiana) territory locations were negatively associated with reed canary grass cover and dominance (which indicated a tendency to place territories where there was no reed canary grass or where many plant species occurred with reed canary grass). Swamp Sparrow territories were positively associated with vegetation height density and litter depth. Common Yellowthroat territories were positively associated with vegetation height density and shrub cover. Song Sparrow territories were negatively associated with litter depth. Reed canary grass cover within territories was not associated with territory size for any of these four bird species. Territory density per plot was not associated with average reed canary grass cover of plots for all four species. Sedge Wrens and Song Sparrows may not respond negatively to reed canary grass because this grass is native to wet meadows of North America, and in the study area it merely replaces other tall lush plants. Avoidance of reed canary grass by Swamp Sparrows may be mediated

  1. Optimisation of logistics processes of energy grass collection

    NASA Astrophysics Data System (ADS)

    Bányai, Tamás.

    2010-05-01

    The collection of energy grass is a logistics-intensive process [1]. The optimal design and control of transportation and collection subprocesses is a critical point of the supply chain. To avoid irresponsible decisions by right of experience and intuition, the optimisation and analysis of collection processes based on mathematical models and methods is the scientific suggestible way. Within the frame of this work, the author focuses on the optimisation possibilities of the collection processes, especially from the point of view transportation and related warehousing operations. However the developed optimisation methods in the literature [2] take into account the harvesting processes, county-specific yields, transportation distances, erosion constraints, machinery specifications, and other key variables, but the possibility of more collection points and the multi-level collection were not taken into consideration. The possible areas of using energy grass is very wide (energetically use, biogas and bio alcohol production, paper and textile industry, industrial fibre material, foddering purposes, biological soil protection [3], etc.), so not only a single level but also a multi-level collection system with more collection and production facilities has to be taken into consideration. The input parameters of the optimisation problem are the followings: total amount of energy grass to be harvested in each region; specific facility costs of collection, warehousing and production units; specific costs of transportation resources; pre-scheduling of harvesting process; specific transportation and warehousing costs; pre-scheduling of processing of energy grass at each facility (exclusive warehousing). The model take into consideration the following assumptions: (1) cooperative relation among processing and production facilties, (2) capacity constraints are not ignored, (3) the cost function of transportation is non-linear, (4) the drivers conditions are ignored. The

  2. Assessing the competitive ability of Japanese stilt grass, Microstegium vimineum (Trin.) A. Camus

    USGS Publications Warehouse

    Leicht, S.A.; Silander, J.A.; Greenwood, K.

    2005-01-01

    Microstegium vimineum (Japanese stilt grass) is an invasive grass in the eastern half of the United States which can form dense monocultures in forest understories, displacing native species. Although the loss of native species has been observed in the field, the actual competitive ability of this grass has not been examined. Microstegium vimineum was grown under controlled environment, greenhouse conditions in competition with Lolium perenne ssp. multiflorum (annual rye grass) and Muhlenbergia mexicana (Mexican muhly) in varying density ratios in full and low light treatments. Microstegium vimineum had a greater aboveground biomass, relative growth rate, and reproductive output than both competitors in both light treatments. The high competitive ability of Microstegium vimineum, especially in low light conditions, reflects its highly aggressive nature in forested or other landscapes of eastern North America.

  3. Asexual endophytes in a native grass: Tradeoffs in mortality, growth, reproduction, and alkaloid production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neotyphodium endophytes are asexual, seed-borne fungal symbionts that are thought to interact mutualistically with their grass hosts. Benefits include increased growth, reproduction, and resistance of herbivores via endophytic alkaloids. Although these benefits are well established in infected int...

  4. Distinguishing grass from ground using LiDAR: Techniques and applications

    NASA Astrophysics Data System (ADS)

    Pelletier, J. D.; Swetnam, T.; Papuga, S. A.; Nelson, K.; Brooks, P. D.; Harpold, A. A.; Chorover, J.

    2011-12-01

    Standard protocols exist for extracting bare-earth Digital Elevation Models (DEMs) from LiDAR point clouds that include trees and other large woody vegetation. Grasses and other herbaceous plants can also obscure the ground surface, yet methods for optimally distinguishing grass from ground to generate accurate LiDAR-based raster products for geomorphic and ecological applications are still under development. Developing such methods is important because LiDAR-based difference products (e.g. snow thickness) require accurate representations of the ground surface and because raster data for grass height and density have important applications in ecology. In this study, we developed and tested methods for constructing optimal bare-earth and grass height raster layers from LiDAR point clouds and compared the results to high-quality field-based measurements of grass height, density, and species type for nearly 1000 precisely geo-referenced locations collected during the acquisition of a >200 km^2 airborne LiDAR flight of the Valles Caldera National Preserve (New Mexico). In cases of partially bare ground (where the skewness of return heights above a plane fit to the lowest first returns is sufficiently large), a planar fit to the lowest first returns provides a good method of producing an accurate bare-earth DEM and the statistics of the first returns above that planar fit provide good estimates of the mean and variance of grass height. In areas of relatively thick grass cover, however, a fit to the lowest first returns yields a bare-earth DEM that may be a meter or more above the actual ground surface. Here we propose a method to solve this problem using field-measured correlations among the mean, variance, and skewness of grass heights. In this method, the variance and skewness of the differences between LiDAR first returns and a 10m^2 planar fit to the lowest first returns is used, together with field-based correlations of grass height statistics, to estimate the mean

  5. Variable effects of fungal endophyte-infected grasses on the performance of pestiferous aphids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The extent of fungal endophyte (Neotyphodium) based antibiosis resistance in temperate grasses (Lolium spp., Hordeum spp.) to five pestiferous aphid species (Rhopalosiphum padi (L.), Diuraphis noxia (Kurdjumov), Schizaphis graminum (Rondani), Metopolophium dirhodum (Walker), Aploneura lentisci (Pass...

  6. Managing soil nitrogen to restore annual grass infested plant communities: an effective strategy or incomplete framework?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theoretical and empirical work has established a positive relationship between resource availability and habitat invasibility. For invasive annual grasses, similar to other invasive species, invader success has been most often tied to increases in nitrogen (N) availability. These observations have...

  7. Narrow grass hedges reduce tylosin and associated antimicrobial resistance genes in agricultural runoff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural runoff from areas receiving livestock manure can potentially contaminate surface water with antimicrobials and antimicrobial resistance genes (ARGs). The objective of this study was to investigate the effectiveness of narrow grass hedges (NGHs) on reducing the transport of antimicrobial...

  8. Evaluation of fine fescue grasses identifies resources for improved ecological function under rangeland stress environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fine-leaved fescue (Festuca ssp.) grasses have potential for contributing to increased rangeland productivity given their comparatively high drought and heat tolerance. Therefore, plant performance trials were developed to evaluate geographically diverse fine fescue materials for their application ...

  9. A novel grass hybrid to reduce flood generation in temperate regions

    PubMed Central

    Macleod, Christopher (Kit) J. A.; Humphreys, Mike W.; Whalley, W. Richard; Turner, Lesley; Binley, Andrew; Watts, Chris W.; Skøt, Leif; Joynes, Adrian; Hawkins, Sarah; King, Ian P.; O'Donovan, Sally; Haygarth, Phil M.

    2013-01-01

    We report on the evaluation of a novel grass hybrid that provides efficient forage production and could help mitigate flooding. Perennial ryegrass (Lolium perenne) is the grass species of choice for most farmers, but lacks resilience against extremes of climate. We hybridised L. perenne onto a closely related and more stress-resistant grass species, meadow fescue Festuca pratensis. We demonstrate that the L. perenne × F. pratensis cultivar can reduce runoff during the events by 51% compared to a leading UK nationally recommended L. perenne cultivar and by 43% compared to F. pratensis over a two year field experiment. We present evidence that the reduced runoff from this Festulolium cultivar was due to intense initial root growth followed by rapid senescence, especially at depth. Hybrid grasses of this type show potential for reducing the likelihood of flooding, whilst providing food production under conditions of changing climate. PMID:23619058

  10. The role of seasonal flowering responses in adaptation of grasses to temperate climates

    PubMed Central

    Fjellheim, Siri; Boden, Scott; Trevaskis, Ben

    2014-01-01

    Grasses of the subfamily Pooideae, including important cereal crops and pasture grasses, are widespread in temperate zones. Seasonal regulation of developmental transitions coordinates the life cycles of Pooideae with the passing seasons so that flowering and seed production coincide with favorable conditions in spring. This review examines the molecular pathways that control the seasonal flowering responses of Pooideae and how variation in the activity of genes controlling these pathways can adapt cereals or grasses to different climates and geographical regions. The possible evolutionary origins of the seasonal flowering responses of the Pooideae are discussed and key questions for future research highlighted. These include the need to develop a better understanding of the molecular basis for seasonal flowering in perennial Pooideae and in temperate grasses outside the core Pooideae group. PMID:25221560

  11. Phytoliths of common grasses in the coastal environments of southeastern USA

    NASA Astrophysics Data System (ADS)

    Lu, Houyuan; Liu, Kam-biu

    2003-11-01

    Thirty-four grass species were collected for phytolith analysis from a variety of coastal environments in the southeastern USA (Georgia, Florida, and Louisiana), including salt marshes, freshwater/brackish marshes, pine/oak forests, maritime hardwood forests, and sand dunes. Phytoliths produced by these modern grasses include a large diversity of shapes and types. We propose a preliminary relationship between modern coastal plant communities and their predominant phytolith contents. The dominant grasses of coastal sand dunes, such as Uniola paniculata, produce primarily flat tower and two-horned tower phytoliths. Rondel/saddle ellipsoid phytoliths are mainly produced by Spartina alterniflora, the most common plant in coastal salt marshes. Rondel and spool/horned tower phytoliths are common in brackish marsh grasses. Plants from interdune meadow produce primarily dumbbell phytoliths, as well as small cross and Cyperaceae-type phytoliths. These results provide a basis for the interpretation of fossil phytolith assemblages and the reconstruction of coastal environmental changes.

  12. A novel grass hybrid to reduce flood generation in temperate regions.

    PubMed

    Macleod, Christopher Kit J A; Humphreys, Mike W; Whalley, W Richard; Turner, Lesley; Binley, Andrew; Watts, Chris W; Skøt, Leif; Joynes, Adrian; Hawkins, Sarah; King, Ian P; O'Donovan, Sally; Haygarth, Phil M

    2013-01-01

    We report on the evaluation of a novel grass hybrid that provides efficient forage production and could help mitigate flooding. Perennial ryegrass (Lolium perenne) is the grass species of choice for most farmers, but lacks resilience against extremes of climate. We hybridised L. perenne onto a closely related and more stress-resistant grass species, meadow fescue Festuca pratensis. We demonstrate that the L. perenne × F. pratensis cultivar can reduce runoff during the events by 51% compared to a leading UK nationally recommended L. perenne cultivar and by 43% compared to F. pratensis over a two year field experiment. We present evidence that the reduced runoff from this Festulolium cultivar was due to intense initial root growth followed by rapid senescence, especially at depth. Hybrid grasses of this type show potential for reducing the likelihood of flooding, whilst providing food production under conditions of changing climate.

  13. Ionomics: Genes and QTLs controlling heavy metal uptake in perennial grasses grown on phytoxic soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial grasses occupy diverse soils throughout the world, including many sites contaminated with heavy metals. Uncovering the genetic architecture of QTLs controlling mineral homoeostasis is critical for understanding the biochemical pathways that determine the elemental profiles of perennial pl...

  14. Spatiotemporal variation in C4-grass abundance during the early to middle Miocene in Spain

    NASA Astrophysics Data System (ADS)

    Urban, M. A.; Nelson, D. M.; Jimenez-Moreno, G.; Hu, F.

    2014-12-01

    Carbon-isotope analyses on a variety of substrates (e.g., leaf waxes, teeth, carbonates) suggest a pronounced increase in C4 plant biomass during the late Miocene and early Pliocene in many regions of the world. This spread of C4-dominated grasslands is thought to have occurred at the expense of C3-dominated grasslands. However, the earlier history of C4 grasses is uncertain, primarily because of difficulty assessing the presence and abundance of C4 grasses when they are relatively rare on the landscape. We measure d13C of individual grass pollen grains using SPIRAL (Single Pollen Isotope Ratio AnaLysis) to distinguish the relative abundance of C3 and C4 grasses during the early to middle Miocene in Spain. We analyzed a total of 3251 pollen grains isolated from 7 samples from Andalucia A1 (10-13.5 Ma), 7 samples from Gor (13-15 Ma) and 24 sediment samples from (Rubielos de Mora, (16-22 Ma). Palynological data indicate that grasses were not a significant component (5-20% of total terrestrial pollen) of the regional vegetation, which was composed of herbs, shrubs, and thermophilous (e.g., Taxodiaceae, Engelhardia) and mesothermic (Quercus, Carya) trees. Based on our SPIRAL data, 21-72% of the grasses were C4, with the older northern site (Rubielos de Mora) having lower C4-grass abundance (average of 39%) than the younger and more southern sites (average of 62%). Paleoclimate reconstructions suggest that the region was mainly subtropical (warm and semi-arid/highly seasonal) at that time, and pollen spectra suggest that the regional vegetation was similar to that found today in northern Africa where C4 grasses dominate. Our pollen-isotope results imply an increase in C4-grass abundance through time, and/or a north-south climatic gradient, with wetter and less seasonal conditions that were less favorable to C4 grasses in the north. Overall, these results suggest that C4 grasses were relatively abundant in southwestern Europe during the early and middle Miocene, prior to

  15. Engineering phenolics metabolism in the grasses using transcription factors

    SciTech Connect

    Grotewold, Erich

    2013-07-26

    The economical competitiveness of agriculture-derived biofuels can be significantly enhanced by increasing biomass/acre yields and by furnishing the desired carbon balance for facilitating liquid fuel production (e.g., ethanol) or for high-energy solid waste availability to be used as biopower (e.g., for electricity production). Biomass production and carbon balance are tightly linked to the biosynthesis of phenolic compounds, which are found in crops and in agricultural residues either as lignins, as part of the cell wall, or as soluble phenolics which play a variety of functions in the biology of plants. The grasses, in particular maize, provide the single major source of agricultural biomass, offering significant opportunities for increasing renewable fuel production. Our laboratory has pioneered the use of transcription factors for manipulating plant metabolic pathways, an approach that will be applied here towards altering the composition of phenolic compounds in maize. Previously, we identified a small group of ten maize R2R3-MYB transcription factors with all the characteristics of regulators of different aspects of phenolic biosynthesis. Here, we propose to investigate the participation of these R2R3-MYB factors in the regulation of soluble and insoluble maize phenolics, using a combination of over-expression and down-regulation of these transcription factors in transgenic maize cultured cells and in maize plants. Maize cells and plants altered in the activity of these regulatory proteins will be analyzed for phenolic composition by targeted metabolic profiling. Specifically, we will I) Investigate the effect of gain- and loss-of-function of a select group of R2R3-MYB transcription factors on the phenolic composition of maize plants and II) Identify the biosynthetic genes regulated by each of the selected R2R3-MYB factors. While a likely outcome of these studies are transgenic maize plants with altered phenolic composition, this research will significantly

  16. Exotic Annual Grasses in Western Rangelands: Predicting Resistance and Resilience of Native Ecosystems to Invasion (Draft)

    DTIC Science & Technology

    2007-11-02

    United States in the late 19th century and soon spread throughout the western states . Bromus now dominates millions of hectares of low and midelevation...as Bromus) is a non-native annual grass from the Mediterranean region that arrived in the United States in the late 19th century and soon spread...Bromus tectorum is an exotic annual grass that has invaded millions of acres in the western United States and is the dominant plant species in

  17. [Type B botulism in cattle, caused by feeding grass silage. Report of a case (author's transl)].

    PubMed

    Haagsma, J; ter Laak, E A

    1978-09-01

    An outbreak of type B botulism in cattle, caused by feeding grass silage, is reported. The clinical features were completely identical with those in cases of type B botulism, which occurred when abnormal brewers' grains were fed. 36.5 mouse LD50 type B toxin was found to be present in each gramme of grass silage, the bacterial count being 10(4) Cl. botulinum type B per gramme.

  18. Differential effects of plant diversity on functional trait variation of grass species

    PubMed Central

    Gubsch, Marlén; Buchmann, Nina; Schmid, Bernhard; Schulze, Ernst-Detlef; Lipowsky, Annett; Roscher, Christiane

    2011-01-01

    Background and Aims Functional trait differences and trait adjustment in response to influences of the biotic environment could reflect niche partitioning among species. In this study, we tested how variation in above-ground plant traits, chosen as indicators for light and nitrogen acquisition and use, differs among taxonomically closely related species (Poaceae) to assess their potential for niche segregation at increasing plant diversity. Methods Traits of 12 grass species were measured in experimental grasslands (Jena Experiment) of varying species richness (from 1 to 60) and presence of particular functional groups (grasses, legumes, tall herbs and small herbs). Key Results Grass species increased shoot and leaf length, investment into supporting tissue (stem mass fraction) and specific leaf area as well as reduced foliar δ13C values with increasing species richness, indicating higher efforts for light acquisition. These species-richness effects could in part be explained by a higher probability of legume presence in more diverse communities. Leaf nitrogen concentrations increased and biomas s : N ratios in shoots decreased when grasses grew with legumes, indicating an improved nitrogen nutrition. Foliar δ15N values of grasses decreased when growing with legumes suggesting the use of depleted legume-derived N, while decreasing δ15N values with increasing species richness indicated a shift in the uptake of different N sources. However, efforts to optimize light and nitrogen acquisition by plastic adjustment of traits in response to species richness and legume presence, varied significantly among grass species. It was possible to show further that trait adjustment of grass species increased niche segregation in more diverse plant communities but that complementarity through niche separation may differ between light and nutrient acquisition. Conclusions The results suggest that even among closely related species such as grasses different strategies are used to

  19. The effect of floodplain grass on the flow characteristics of meandering compound channels

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Shan, Yuqi; Liu, Xingnian; Yang, Kejun; Liao, Huasheng

    2016-11-01

    Laboratory experiments were conducted in a large-scale meandering compound channel to investigate the effect of floodplain grass on the main flow field in the channel. Three-dimensional velocity fields, turbulences, and Reynolds shear stresses were measured along half a meander. The experiments revealed that flexible artificial grass planted on a floodplain can significantly reduce the conveyance capability of the entire channel. Two parallel stage-discharge curves increased with increasing flow depth. The additional resistance of the floodplain grass increased the streamwise velocity and conveyance in the main channel along a meander. An analysis of the generation mechanism of secondary flows in the main channel indicated that the secondary current consisted of an enhanced original secondary cell that was strengthened by the centrifugal force and a component of the upstream floodplain flow. The relative dominance of these two components in the secondary flows was primarily determined by the angle between the floodplain flow and the main channel ridge, and also the floodplain roughness. At the same flow depth, the secondary flow in cases with grass on the floodplain was generally stronger than that in the case of a smooth meander bend, although it was weaker near the middle cross-over section. Floodplain grass enhanced the intensity of the lateral turbulence above the bankfull level and significantly modified the turbulence structure, although it had a negligible effect on the vertical turbulence except at the bend entrance. Floodplain grass also affected the Reynolds shear stresses in the main channel, generating stronger lateral shear stresses at a low flow depth. In contrast, at a high flow depth, the distribution of the interface shear stresses changed entirely while its magnitude remained the same. When the floodplains were grassed, the vertical shear stress that was induced by secondary flows was greater at the apexes but reduced at the cross-over sections

  20. Molecular evolution of hypoallergenic hybrid proteins for vaccination against grass pollen allergy.

    PubMed

    Linhart, Birgit; Focke-Tejkl, Margarete; Weber, Milena; Narayanan, Meena; Neubauer, Angela; Mayrhofer, Hannes; Blatt, Katharina; Lupinek, Christian; Valent, Peter; Valenta, Rudolf

    2015-04-15

    More than 10% of the population in Europe and North America suffer from IgE-associated allergy to grass pollen. In this article, we describe the development of a vaccine for grass pollen allergen-specific immunotherapy based on two recombinant hypoallergenic mosaic molecules, designated P and Q, which were constructed out of elements derived from the four major timothy grass pollen allergens: Phl p 1, Phl p 2, Phl p 5, and Phl p 6. Seventeen recombinant mosaic molecules were expressed and purified in Escherichia coli using synthetic genes, characterized regarding biochemical properties, structural fold, and IgE reactivity. We found that depending on the arrangement of allergen fragments, mosaic molecules with strongly varying IgE reactivity were obtained. Based on an extensive screening with sera and basophils from allergic patients, two hypoallergenic mosaic molecules, P and Q, incorporating the primary sequence elements of the four grass pollen allergens were identified. As shown by lymphoproliferation experiments, they contained allergen-specific T cell epitopes required for tolerance induction, and upon immunization of animals induced higher allergen-specific IgG Abs than the wild-type allergens and a registered monophosphoryl lipid A-adjuvanted vaccine based on natural grass pollen allergen extract. Moreover, IgG Abs induced by immunization with P and Q inhibited the binding of patients' IgE to natural allergens from five grasses better than IgG induced with the wild-type allergens or an extract-based vaccine. Our results suggest that vaccines based on the hypoallergenic grass pollen mosaics can be used for immunotherapy of grass pollen allergy.