Science.gov

Sample records for grass pennisetum clandestinum

  1. Phytoremediation of landfill leachate using Pennisetum clandestinum.

    PubMed

    Sögüt, Zerrin; Zaimoglu, B Zeynep; Erdogan, Reyhan; Sucu, M Yavuz

    2005-01-01

    Landfills are still the most widely used solid waste disposal method used across the world. Leachate generated from landfill areas exerts environmental risks mostly on surface and groundwater, with its high pollutant content, most notably metals, which cause an unbearable lower water quality. During dumping or after the capacity of the landfill has been reached, a decontamination and remediation program should be taken for the area. This study was conducted to assess the capacity and efficiency of Pennisetum clandestinum, a prostrate perennial plant, to accumulate chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), zinc (Zn) and lead (Pb). Leachate, taken from the Sofulu Landfill Site, was given to Pennisetum clandestinum for 180 days, in 3 dilution sets as 1/1, 1/2 and 1/4, in batch configuration. An additional control set was also installed for comparison. Results showed that, even though the metal content of soil had risen, plants accumulated 2 to 8.5 times higher concentrations than the control set. It is important to see, the plant showed almost no stress symptoms even if the set was fed by pure leachate. Pennisetum clandestinum was observed to accumulate metals mostly in the upper bodies, excluding Fe and Cu. 76% of accumulated Cr, 85% of Ni, 66% of Zn and 100% of Pb was observed to accumulate in above-ground parts, where only 20% of Cu and 4% of Fe was accumulated. Due to the high pollution tolerance of Pennisetum clandestinum, makes this plant suitable for decontamination and remediation of landfill sites.

  2. Fusarium species isolated from Pennisetum clandestinum collected during outbreaks of kikuyu poisoning in cattle in South Africa.

    PubMed

    Botha, Christo J; Truter, Mariëtte; Jacobs, Adriaana

    2014-11-20

    Kikuyu poisoning occurs sporadically in South Africa. It is of major economic importance, as valuable dairy cows are often poisoned by it, and once affected, the mortality rate is high. Pennisetum clandestinum samples were collected during eight outbreaks of kikuyu poisoning in cattle in the Eastern Cape Province of South Africa from 2008 to 2010. The kikuyu grass samples were submitted specifically for the isolation and molecular identification of Fusarium species, as it was recently suggested that mycotoxins synthesised by Fusarium torulosum could be the cause of this intoxication. Ninety-four Fusarium isolates were retrieved from the grass samples, of which 72 were members of the Fusarium incarnatum/Fusarium equiseti species complex based on morphology and phylogenetic analyses of the translation elongation factor 1α sequence data. The South African isolates from kikuyu identified as members of the F. incarnatum/F. equiseti species complex grouped together in six separate clades. The other isolates were Fusarium culmorum (n = 3), Fusarium redolens (n = 4) and Fusarium oxysporum (n = 15). Although F. torulosum could not be isolated from P. clandestinum collected during kikuyu poisoning outbreaks in South Africa, the mycotoxicosis theory is still highly plausible.

  3. Thiaminase activities and thiamine content of Pteridium aquilinum, Equisetum ramosissimum, Malva parviflora, Pennisetum clandestinum and Medicago sativa.

    PubMed

    Meyer, P

    1989-06-01

    Thiaminase type 1 and 2 activities and thiamine content of five plants were determined. Of these Pteridium aquilinum and Equisetum ramosissimum were found to have considerably more thiaminase activity and lower thiamine content than Malva parviflora, Pennisetum clandestinum and Medicago sativa.

  4. 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.

  5. 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.

  6. Use of elephant grass (Pennisetum purpureum) acid hydrolysate for microbial oil production by Trichosporon cutaneum.

    PubMed

    Chen, Xue-Fang; Huang, Chao; Xiong, Lian; Wang, Bo; Qi, Gao-Xiang; Lin, Xiao-Qing; Wang, Can; Chen, Xin-De

    2016-10-01

    Elephant grass (Pennisetum purpureum) dilute acid hydrolysate contains 34.6 g/L total sugars. The potential of lipid production by oleaginous yeast Trichosporon cutaneum grown on elephant grass acid hydrolysate was investigated for the first time. During the fermentation process on the elephant grass acid hydrolysate, glucose, xylose, and arabinose could be well utilized as carbon sources by T. cutaneum. Interestingly, xylose was almost no use before glucose was consumed completely. This illustrated that simultaneous saccharification of xylose and glucose by T. cutaneum did not occur on elephant grass acid hydrolysate. The highest biomass, lipid content, lipid yield, and lipid coefficient of T. cutaneum were measured after the sixth day of fermentation and were 22.76 g/L, 24.0%, 5.46 g/L, and 16.1%, respectively. Therefore, elephant grass is a promising raw material for microbial oil production by T. cutaneum.

  7. Tissue-specific genome instability in synthetic interspecific hybrids of Pennisetum purpureum (Napier grass) and Pennisetum glaucum (pearl millet) is caused by micronucleation.

    PubMed

    Dos Reis, Gabriela Barreto; Ishii, Takayoshi; Fuchs, Joerg; Houben, Andreas; Davide, Lisete Chamma

    2016-09-01

    Genome instability is observed in several species hybrids. We studied the mechanisms underlying the genome instability in hexaploid hybrids of Napier grass (Pennisetum purpureum R.) and pearl millet (Pennisetum glaucum L.) using a combination of different methods. Chromosomes of both parental genomes are lost by micronucleation. Our analysis suggests that genome instability occurs preferentially in meristematic root tissue of hexaploid hybrids, and chromosome elimination is not only caused by centromere inactivation. Likely, beside centromere dysfunction, unrepaired DNA double-strand breaks result in fragmented chromosomes in synthetic hybrids.

  8. 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.

  9. 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...

  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. Genetic diversity in Napier grass (Pennisetum purpureum) cultivars: implications for breeding and conservation.

    PubMed

    Wanjala, Bramwel W; Obonyo, Meshack; Wachira, Francis N; Muchugi, Alice; Mulaa, Margaret; Harvey, Jagger; Skilton, Robert A; Proud, Janice; Hanson, Jean

    2013-01-01

    Napier grass is an important forage crop for dairy production in the tropics; as such, its existing genetic diversity needs to be assessed for conservation. The current study assessed the genetic variation of Napier grass collections from selected regions in Eastern Africa and the International Livestock Research Institute Forage Germplasm-Ethiopia. The diversity of 281 cultivars was investigated using five selective amplified fragment length polymorphism (AFLP) markers and classical population genetic parameters analysed using various software. The number of bands generated was 216 with fragments per primer set ranging from 50 to 115. Mean percentage polymorphic loci was 63.40. Genetic diversity coefficients based on Nei's genetic diversity ranged from 0.0783 to 0.2142 and Shannon's information index ranged from 0.1293 to 0.3445. The Fst value obtained was moderately significant (Fst = 0.1688). Neighbour-joining analysis gave two distinct clusters which did not reflect geographical locations. Analysis of molecular variance showed all variance components to be highly significant (P < 0.001), indicating more variation within (91 %) than between populations (9 %). Results suggested moderate genetic differentiation among Napier grass populations sampled, which could imply a high germplasm exchange within the region. The AFLP markers used in this study efficiently discriminate among cultivars and could be useful in identification and germplasm conservation.

  12. Genetic diversity in Napier grass (Pennisetum purpureum) cultivars: implications for breeding and conservation

    PubMed Central

    Wanjala, Bramwel W.; Obonyo, Meshack; Wachira, Francis N.; Muchugi, Alice; Mulaa, Margaret; Harvey, Jagger; Skilton, Robert A.; Proud, Janice; Hanson, Jean

    2013-01-01

    Napier grass is an important forage crop for dairy production in the tropics; as such, its existing genetic diversity needs to be assessed for conservation. The current study assessed the genetic variation of Napier grass collections from selected regions in Eastern Africa and the International Livestock Research Institute Forage Germplasm-Ethiopia. The diversity of 281 cultivars was investigated using five selective amplified fragment length polymorphism (AFLP) markers and classical population genetic parameters analysed using various software. The number of bands generated was 216 with fragments per primer set ranging from 50 to 115. Mean percentage polymorphic loci was 63.40. Genetic diversity coefficients based on Nei's genetic diversity ranged from 0.0783 to 0.2142 and Shannon's information index ranged from 0.1293 to 0.3445. The Fst value obtained was moderately significant (Fst = 0.1688). Neighbour-joining analysis gave two distinct clusters which did not reflect geographical locations. Analysis of molecular variance showed all variance components to be highly significant (P < 0.001), indicating more variation within (91 %) than between populations (9 %). Results suggested moderate genetic differentiation among Napier grass populations sampled, which could imply a high germplasm exchange within the region. The AFLP markers used in this study efficiently discriminate among cultivars and could be useful in identification and germplasm conservation. PMID:23671788

  13. Genetic diversity in Napier grass (Pennisetum purpureum) cultivars: implications for breeding and conservation.

    PubMed

    Wanjala, Bramwel W; Obonyo, Meshack; Wachira, Francis N; Muchugi, Alice; Mulaa, Margaret; Harvey, Jagger; Skilton, Robert A; Proud, Janice; Hanson, Jean

    2013-01-01

    Napier grass is an important forage crop for dairy production in the tropics; as such, its existing genetic diversity needs to be assessed for conservation. The current study assessed the genetic variation of Napier grass collections from selected regions in Eastern Africa and the International Livestock Research Institute Forage Germplasm-Ethiopia. The diversity of 281 cultivars was investigated using five selective amplified fragment length polymorphism (AFLP) markers and classical population genetic parameters analysed using various software. The number of bands generated was 216 with fragments per primer set ranging from 50 to 115. Mean percentage polymorphic loci was 63.40. Genetic diversity coefficients based on Nei's genetic diversity ranged from 0.0783 to 0.2142 and Shannon's information index ranged from 0.1293 to 0.3445. The Fst value obtained was moderately significant (Fst = 0.1688). Neighbour-joining analysis gave two distinct clusters which did not reflect geographical locations. Analysis of molecular variance showed all variance components to be highly significant (P < 0.001), indicating more variation within (91 %) than between populations (9 %). Results suggested moderate genetic differentiation among Napier grass populations sampled, which could imply a high germplasm exchange within the region. The AFLP markers used in this study efficiently discriminate among cultivars and could be useful in identification and germplasm conservation. PMID:23671788

  14. 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.

  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. 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.

  17. [Coffee pulp and hulls. XI. Chemical characteristics of silaged coffee pulp with Napier grass (Pennisetum purpurem) and corn plant (Zea mays)].

    PubMed

    Murillo, B; Daqui, L; Cabezas, M T; Bressani, R

    1976-03-01

    Various physical and chemical changes that occur during the process of preparation of coffee pulp silage with the addition of molasses and forage, were identified and measured quantitatively. Three types of silage were prepared in duplicate in laboratory concrete silos, 45 cm wide and 50 cm high. The silages contained the following components: coffee pulp (EPC), pulp and Napier grass (EPCN), and pulp with corn fodder (EPCM). On a fresh basis, the last two contained equal proportions of coffee pulp and forage. Around 16% molasses were aded to all silages. Time of ensiling was 132 to 141 days. In order to determine the physical changes, the silage was weighed at the start and end of the ensiling period; the pH was determined at the end of same, and the drained liquids were measured during the experimental period. To determine the chemical changes, analyses were carried out on the various components used and on the mixtures ensiled at the start and at the end of the experimental period. The pH of the silage was 4.5, 4.3, and 3.8, and the losses of dry matter 10.6, 25.2, and 33.3% for the three types of silages, respectively. These percentages suggest that a better fermentation took place in those silages containing forages. The better fermentation of EPCN over EPC was due to the Napier grass which provided greater amounts of chemical components susceptible of fermentation than those found in coffee pulp. The quality of EPCM was superior due not only to the presence of corn fodder, which produced an effect similar to that of Napier grass, but also due to the fact that the coffee pulp used in this case contained the greater concentrations of soluble carbohydrates and lower levels of lignin than the coffee pulp used alone or with Napier grass. As a result of the fermentation process, in all three types of silage a decrease in dry matter content, of cellular contents and soluble carbohydrates was observed, as well as an increase in cellular walls and its components, and

  18. Genetic relationships among napiergrass (Pennisetum purpureum Schum.) nursery accessions using AFLP markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pennisetum purpureum Schum. (napier grass) is a perennial grass used for forage especially in South America and Africa. The species has large morphological variation and over the last thirty years a USDA-ARS nursery has been established in Tifton, GA. Accessions have been collected worldwide and thi...

  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. [Effects of different years of planting Pennisetum sp. on the plant- and insect diversity in Pennisetum sp. communities].

    PubMed

    Lin, Xing-Sheng; Lin, Zhan-Xi; Lin, Dong-Mei; Lin, Hui; Luo, Hai-Ling; Hu, Ying-Ping; Lin, Chun-Mei; Zhu, Chao-Zhi

    2012-10-01

    This paper studied the effects of 1-, 2- and 3 years of planting Pennisetum sp. on the plant- and insect diversity in the Pennisetum sp. communities, taking the barren mountain land without planting Pennisetum sp. as the control (CK). Compared with CK, the plant species richness in Pennisetum sp. communities with different years of planting was lower, but the coverage was higher. The coverage in the Pennisetum sp. community having been planted for 3 years was the highest, up to 91.6%, and 75.8% higher than the CK. The insect species richness in the Pennisetum sp. communities having been planted for 1, 2 and 3 years was 3.6, 5.3 and 5.6 times of the CK, respectively. The plant- and insect diversity indices, including Simpson index, Shannon index, evenness, Brillouin index, and McIntosh index for the Pennisetum sp. communities with different years of planting were significantly higher than the CK, which indicated that the growth of Pennisetum sp. could affect the plant- and insect diversity. With the increasing year of planting, the plant- and insect diversity in Pennisetum sp. communities tended to be stable.

  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

    2015-01-01

    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. PMID:26624644

  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. Microwave torrefaction of rice straw and Pennisetum.

    PubMed

    Huang, Y F; Chen, W R; Chiueh, P T; Kuan, W H; Lo, S L

    2012-11-01

    Microwave torrefaction of rice straw and pennisetum was researched in this article. Higher microwave power levels contributed to higher heating rate and reaction temperature, and thus produced the torrefied biomass with higher heating value and lower H/C and O/C ratios. Kinetic parameters were determined with good coefficients of determination, so the microwave torrefaction of biomass might be very close to first-order reaction. Only 150W microwave power levels and 10min processing time were needed to meet about 70% mass yield and 80% energy yield for torrefied biomass. The energy density of torrefied biomass was about 14% higher than that of raw biomass. The byproducts (liquid and gas) possessed about 30% mass and 20% energy of raw biomass, and they can be seen as energy sources for heat or electricity. Microwave torrefaction of biomass could be a competitive technology to employ the least energy and to retain the most bioenergy.

  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. Grass allergy

    MedlinePlus

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

  7. 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...

  8. 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

  9. 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.

  10. 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. PMID:27031857

  11. 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.

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

    PubMed

    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

  13. 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.

  14. 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. PMID:26233251

  15. Relationship of light quantity and anthocyanin production in Pennisetum setaceum Cvs. rubrum and red riding hood.

    PubMed

    Beckwith, Andrea G; Zhang, Yanjun; Seeram, Navindra P; Cameron, Arthur C; Nair, Muraleedharan G

    2004-02-11

    Pennisetum setaceum cvs. Rubrum and Red Riding Hood are purple-pigmented ornamental grasses when grown in high-light environments. In low-light environments, foliage appears light purple or green, and as a result, aesthetic appeal is reduced. The impact of light on anthocyanin pigmentation was compared for P. setaceum Rubrum foliage and flowers and Red Riding Hood foliage grown under different light intensities and light sources. Light environments included UV supplemental light in the greenhouse, high-pressure sodium supplemental light in the greenhouse, cool-white fluorescent light in a growth chamber, and full sun outside. Anthocyanins in two cultivars of P. setaceum were analyzed by HPLC and characterized by (1)H and (13)C NMR spectral experiments. Two anthocyanins, cyanidin 3-glucoside and cyanidin 3-rutinoside, were identified in the leaves and flowers of both cultivars and quantified by HPLC analysis. The major anthocyanin in both cultivars was cyanidin 3-glucoside and had highest concentration (0.199% fresh weight) in Rubrum leaves grown under fluorescent lights in the growth chamber with a photoperiod of 24 h and a daily light integral (DLI) of 13.3 mol m(-)(2) day(-)(1) and in Rubrum and Red Riding Hood leaves and flowers (0.097 and 0.12% fresh weight) from plants grown outside in full sun with a photoperiod ranging from 15 to 13.5 h and DLI of 42 mol m(-)(2) day(-)(1). The minor anthocyanin, cyanidin 3-rutinoside, had the highest quantity in plants grown in low-light-intensity greenhouse environments with a photoperiod ranging from 15 to 13.5 h and DLI of 2.3-7.0 mol m(-)(2) day(-)(1). The functional significance of anthocyanins in P. setaceum Rubrum is discussed.

  16. Characterization of modified pearl millet (Pennisetum typhoides) starch.

    PubMed

    Balasubramanian, S; Sharma, R; Kaur, J; Bhardwaj, N

    2014-02-01

    Pearl millet starch (Pennisetum typhoides) was isolated and subjected to hydrothermal, acidic and enzymatic modifications. Native and various modified starches were characterized in terms of yield, moisture, protein, ash, bulk density, swelling power, solubility, colour, sediment volume, gel consistency, water binding capacity, pasting properties, freeze thaw stability and paste clarity. Hydrothermal modification (HTMS) caused an increase in swelling power and solubility. L value was higher for acid and enzymatically modified starches (EMS). A significant reduction (p ≤ 0.05) in sediment volume and water binding capacity was observed for acid modified starch (AMS) and EMS. Peak viscosity values declined for all modifications. However, EMS and AMS showed an improved freeze-thaw stability and paste clarity. PMID:24493886

  17. Allergy to grass juice.

    PubMed

    Niinimäki, A

    1977-06-01

    Crushed, fresh grass did not produce positive skin reactions in 149 patients with grass pollen allergy, six of whom suffered from rhinitis and conjunctival discharge while cutting grass. An additional patient without an allergy to grass pollens but with clear-cut symptoms from newly cut grass showed a negative result in the scratch-chamber test and in the scrubbing test.

  18. Grass Lignocellulose

    NASA Astrophysics Data System (ADS)

    Akin, Danny E.

    Grass lignocelluloses are limited in bioconversion by aromatic constituents, which include both lignins and phenolic acids esters. Histochemistry, ultraviolet absorption microspectrophotometry, and response to microorganisms and specific enzymes have been used to determine the significance of aromatics toward recalcitrance. Coniferyl lignin appears to be the most effective limitation to biodegradation, existing in xylem cells of vascular tissues; cell walls with syringyl lignin, for example, leaf sclerenchyma, are less recalcitrant. Esterified phenolic acids, i.e., ferulic and p-coumaric acids, often constitute a major chemical limitation in nonlignified cell walls to biodegradation in grasses, especially warm-season species. Methods to improve biodegradability through modification of aromatics include: plant breeding, use of lignin-degrading white-rot fungi, and addition of esterases. Plant breeding for new cultivars has been especially effective for nutritionally improved forages, for example, bermudagrasses. In laboratory studies, selective white-rot fungi that lack cellulases delignified the lignocellulosic materials and improved fermentation of residual carbohydrates. Phenolic acid esterases released p-coumaric and ferulic acids for potential coproducts, improved the available sugars for fermentation, and improved biodegradation. The separation and removal of the aromatic components for coproducts, while enhancing the availability of sugars for bioconversion, could improve the economics of bioconversion.

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Endogenous Abscisic Acid and Indole-3-Acetic Acid and Somatic Embryogenesis in Cultured Leaf Explants of Pennisetum purpureum Schum. 1

    PubMed Central

    Rajasekaran, Kanniah; Hein, Mich B.; Vasil, Indra K.

    1987-01-01

    Effects of application in vivo of glyphosate, fluridone, and paclobutrazol to glasshouse-grown donor plants of Pennisetum purpureum Schum. on endogenous levels of abscisic acid (ABA) and indole-3-acetic acid (IAA) in young leaves and on somatic embryogenesis in cultured leaf explants were studied. Treatment of plants with glyphosate (100 milligrams per liter) resulted in elevated levels of endogenous ABA and IAA in young leaves. In contrast, paclobutrazol (50% active ingredient; 200 milligrams per liter) did not alter the endogenous levels of ABA and IAA. Fluridone (100 milligrams per liter) markedly inhibited synthesis of ABA and leaf explants from fluridone-treated plants lost the capacity for somatic embryogenesis. Explants from glyphosate- or paclobutrazol-treated plants did not show any reduction in embryogenic capacity when compared with untreated control plants. Glyphosate and fluridone were also incorporated into the culture media at various concentrations (0 to 20 milligrams per liter) to study their effects in vitro on somatic embryogenesis in leaf explants from untreated, field-grown plants. Glyphosate was inhibitory to somatic embryogenesis but only at concentrations above 5 milligrams per liter. Fluridone inhibited somatic embryogenesis at all concentrations tested. Inhibition of somatic embryogenesis by fluridone, by either in vivo or in vitro application, could be overcome partially by (±)-ABA added to the culture medium. Exogenous application of (±)-ABA enhanced somatic embryogenesis and reduced the formation of nonembryogenic callus. Application of IAA or gibberellic acid (GA3; >5 milligrams per liter) was inhibitory to somatic embryogenesis. These results indicate that endogenous ABA is one of the important factors controlling the embryogenic capacity of leaf explants in Napier grass. PMID:16665403

  5. 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

  6. 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...

  7. 7 CFR 319.41 - Notice of quarantine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...), grain sorghums (Andropogon sorghum), Sudan grass (Andropogon sorghum sudanensis), Johnson grass... (Pennisetum glaucum), napier grass (Pennisetum purpureum), teosinte (Euchlaena luxurians), and...

  8. 7 CFR 319.41 - Notice of quarantine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...), grain sorghums (Andropogon sorghum), Sudan grass (Andropogon sorghum sudanensis), Johnson grass... (Pennisetum glaucum), napier grass (Pennisetum purpureum), teosinte (Euchlaena luxurians), and...

  9. 7 CFR 319.41 - Notice of quarantine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...), grain sorghums (Andropogon sorghum), Sudan grass (Andropogon sorghum sudanensis), Johnson grass... (Pennisetum glaucum), napier grass (Pennisetum purpureum), teosinte (Euchlaena luxurians), and...

  10. 7 CFR 319.41 - Notice of quarantine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...), grain sorghums (Andropogon sorghum), Sudan grass (Andropogon sorghum sudanensis), Johnson grass... (Pennisetum glaucum), napier grass (Pennisetum purpureum), teosinte (Euchlaena luxurians), and...

  11. 7 CFR 319.41 - Notice of quarantine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...), grain sorghums (Andropogon sorghum), Sudan grass (Andropogon sorghum sudanensis), Johnson grass... (Pennisetum glaucum), napier grass (Pennisetum purpureum), teosinte (Euchlaena luxurians), and...

  12. 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.

  13. 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. PMID:27101877

  14. 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.

  15. 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

  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. 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. PMID:25727997

  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. 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.

  1. Orally administered grass pollen.

    PubMed

    Taudorf, E; Weeke, B

    1983-11-01

    In 1900 it was claimed that oral administration of ragweed could be used for the hyposensitization of hay fever patients. Several uncontrolled trials have been published, all showing an effect of oral hyposensitization. Only one study was controlled and showed no effect of oral hyposensitization. It was decided to undertake controlled clinical trials to determine the safety and effectiveness of orally administered enteric-coated grass pollen tablets in patients with hay fever. The actual grass pollen dose in the first trial was 30 times the dose that is normally recommended for preseasonal oral pollen hyposensitization using pollen aqueous solution or pollen powder. The safety study will be described here. Twelve young adults with a history of grass pollen hay fever positive skin prick test and positive nasal provocation test with extracts of timothy grass pollen were randomly allocated to one of the treatment groups with four patients in each group taking enteric-coated Conjuvac Timothy tablets or enteric-coated Whole Timothy pollen tablets or enteric-coated placebo tablets. The study was double blind. Preseasonally, the patients received 342,500 PNU and in total they received 4,500,000 PNU during 6 months. The patients receiving active treatment did not have any side effects. No significant changes were shown in the skin and nasal reactivity to grass pollen during the study. Neither were there any changes in timothy-specific IgE, IgG, total IgE nor histamine liberation from basophils.

  2. 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.

  3. 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.

  4. Combined bioremediation of atrazine-contaminated soil by Pennisetum and Arthrobacter sp. strain DNS10.

    PubMed

    Zhang, Ying; Ge, Shijie; Jiang, Mingyue; Jiang, Zhao; Wang, Zhigang; Ma, Bingbing

    2014-05-01

    Strain DNS10 was isolated from the black soil collected from the northeast of China which had been cultivated with atrazine as the sole nitrogen source. Pennisetum is a common plant in Heilongjiang Province of China. The main objective of this paper was to evaluate the efficiency of plant-microbe joint interactions (Arthrobacter sp. DNS10 + Pennisetum) in atrazine degradation compared with single-strain and single-plant effects. Plant-microbe joint interactions degraded 98.10 % of the atrazine, while single strain and single plant only degraded 87.38 and 66.71 % after a 30-day experimental period, respectively. The results indicated that plant-microbe joint interactions had a better degradation effect. Meanwhile, we found that plant-microbe joint interactions showed a higher microbial diversity. The results of microbial diversity illustrated that the positive effects of cropping could improve soil microbial growth and activity. In addition, we planted atrazine-sensitive plants (soybean) in the soil after repair. The results showed that soybean growth in soil previously treated with the plant-microbe joint interactions treatment was better compared with other treatments after 20 days of growth. This was further proved that the soil is more conducive for crop cultivation. Hence, plant-microbe joint interactions are considered to be a potential tool in the remediation of atrazine-contaminated soil.

  5. Production of napiergrass (Pennisetum purpureum Schum) for bioenergy under organic versus inorganic fertilization in the southeast USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Napiergrass (Pennisetum purpureum Schum.) is being considered for use as a feedstock for the emerging bioenergy industry in the Southeast USA. However, research is needed to determine the most efficient and sustainable means of producing this crop for bioenergy in this region. Poultry litter is a...

  6. 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 ...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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. PMID:22281146

  12. 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.

  13. 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…

  14. 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). PMID:26897473

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. The dynamics of LTR retrotransposon accumulation across 25 million years of panicoid grass evolution.

    PubMed

    Estep, M C; DeBarry, J D; Bennetzen, J L

    2013-02-01

    Sample sequence analysis was employed to investigate the repetitive DNAs that were most responsible for the evolved variation in genome content across seven panicoid grasses with >5-fold variation in genome size and different histories of polyploidy. In all cases, the most abundant repeats were LTR retrotransposons, but the particular families that had become dominant were found to be different in the Pennisetum, Saccharum, Sorghum and Zea lineages. One element family, Huck, has been very active in all of the studied species over the last few million years. This suggests the transmittal of an active or quiescent autonomous set of Huck elements to this lineage at the founding of the panicoids. Similarly, independent recent activity of Ji and Opie elements in Zea and of Leviathan elements in Sorghum and Saccharum species suggests that members of these families with exceptional activation potential were present in the genome(s) of the founders of these lineages. In a detailed analysis of the Zea lineage, the combined action of several families of LTR retrotransposons were observed to have approximately doubled the genome size of Zea luxurians relative to Zea mays and Zea diploperennis in just the last few million years. One of the LTR retrotransposon amplification bursts in Zea may have been initiated by polyploidy, but the great majority of transposable element activations are not. Instead, the results suggest random activation of a few or many LTR retrotransposons families in particular lineages over evolutionary time, with some families especially prone to future activation and hyper-amplification.

  1. The dynamics of LTR retrotransposon accumulation across 25 million years of panicoid grass evolution

    PubMed Central

    Estep, M C; DeBarry, J D; Bennetzen, J L

    2013-01-01

    Sample sequence analysis was employed to investigate the repetitive DNAs that were most responsible for the evolved variation in genome content across seven panicoid grasses with >5-fold variation in genome size and different histories of polyploidy. In all cases, the most abundant repeats were LTR retrotransposons, but the particular families that had become dominant were found to be different in the Pennisetum, Saccharum, Sorghum and Zea lineages. One element family, Huck, has been very active in all of the studied species over the last few million years. This suggests the transmittal of an active or quiescent autonomous set of Huck elements to this lineage at the founding of the panicoids. Similarly, independent recent activity of Ji and Opie elements in Zea and of Leviathan elements in Sorghum and Saccharum species suggests that members of these families with exceptional activation potential were present in the genome(s) of the founders of these lineages. In a detailed analysis of the Zea lineage, the combined action of several families of LTR retrotransposons were observed to have approximately doubled the genome size of Zea luxurians relative to Zea mays and Zea diploperennis in just the last few million years. One of the LTR retrotransposon amplification bursts in Zea may have been initiated by polyploidy, but the great majority of transposable element activations are not. Instead, the results suggest random activation of a few or many LTR retrotransposons families in particular lineages over evolutionary time, with some families especially prone to future activation and hyper-amplification. PMID:23321774

  2. 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

  3. 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

  4. Videographic enhancement of GRASS imagery: Recent advances

    SciTech Connect

    Sullivan, R.G.

    1992-06-01

    The Geographic Resource Analysis Support System (GRASS), a geographic information system, has been fielded at approximately 50 US Army training installations as a land-management decision-making tool. Use of the GRASS geographic information system involves the production of numerous digital maps of environmental parameters, such as elevation, soils, hydrography, etc. A recently emerging technology called computer videographics can be used to graphically enhance GRASS images, thereby creating new ways to visualize GRASS analysis results. The project described in this report explored the enhancement of GRASS images through the use of videographic technology. General image quality of videographically enhanced GRASS images was improved through the use of high-resolution imagery and improved software. Several new types of geographic data visualizations were developed, including three-dimensional shaded-relief maps of GRASS data, overlay of GRASS images with satellite images, and integration of computer-aided-design imagery with GRASS images. GRASS images were successfully enhanced using Macintosh hardware and software, rather than the DOS-based equipment used previously. Images scanned with a document scanner were incorporated into GRASS imagery, and enhanced images were output in an S-VHS high-resolution video format.

  5. Symbiotic grasses: A review of basic biology of forage grass fungal endophytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal endophytes associated with grasses are the fundamental reason for the basic successes of several pasture grasses, notable tall fescues, and perennial ryegrass. Tall fescue and perennial ryegrass fungal endophytes, Neotyphodium coenophialum and N. lolii, respectively, and their relatives ...

  6. 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.

  7. Simplified dynamic models of grass field ecosystem

    NASA Astrophysics Data System (ADS)

    Zeng, Qingcun; Zeng, Xiaodong; Lu, Peisheng

    1994-12-01

    Some simplified dynamic models of grass field ecosystem are developed and investigated. The maximum simplified one consists of two variables, living grass biomass and soil wetness. The analyses of such models show that there exists only desert regime without grasses if the precipitation p is less than a critical value p c ; the grass biomass continuously depends on p if the interaction between grass biomass and the soil wetness is weak, but the strong interaction results in the bifurcation of grass biomass in the vicinity of p c : the grass biomass is rich as p > p c , but it becomes desertification as p

    grass biomass x, the nonliving grass biomass accumulated on the ground surface y and the soil wetness z. The behaviours of such three variables model are more complicated. The initial values of y and z play a very important role.

  8. 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.

  9. 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. PMID:27226761

  10. 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

  11. 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.

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

    PubMed

    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

  13. 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.

  14. 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.

  15. Sequence analysis of bacterial artificial chromosome clones from the apospory-specific genomic region of Pennisetum and Cenchrus.

    PubMed

    Conner, Joann A; Goel, Shailendra; Gunawan, Gunawati; Cordonnier-Pratt, Marie-Michele; Johnson, Virgil Ed; Liang, Chun; Wang, Haiming; Pratt, Lee H; Mullet, John E; DeBarry, Jeremy; Yang, Lixing; Bennetzen, Jeffrey L; Klein, Patricia E; Ozias-Akins, Peggy

    2008-07-01

    Apomixis, asexual reproduction through seed, is widespread among angiosperm families. Gametophytic apomixis in Pennisetum squamulatum and Cenchrus ciliaris is controlled by the apospory-specific genomic region (ASGR), which is highly conserved and macrosyntenic between these species. Thirty-two ASGR bacterial artificial chromosomes (BACs) isolated from both species and one ASGR-recombining BAC from P. squamulatum, which together cover approximately 2.7 Mb of DNA, were used to investigate the genomic structure of this region. Phrap assembly of 4,521 high-quality reads generated 1,341 contiguous sequences (contigs; 730 from the ASGR and 30 from the ASGR-recombining BAC in P. squamulatum, plus 580 from the C. ciliaris ASGR). Contigs containing putative protein-coding regions unrelated to transposable elements were identified based on protein similarity after Basic Local Alignment Search Tool X analysis. These putative coding regions were further analyzed in silico with reference to the rice (Oryza sativa) and sorghum (Sorghum bicolor) genomes using the resources at Gramene (www.gramene.org) and Phytozome (www.phytozome.net) and by hybridization against sorghum BAC filters. The ASGR sequences reveal that the ASGR (1) contains both gene-rich and gene-poor segments, (2) contains several genes that may play a role in apomictic development, (3) has many classes of transposable elements, and (4) does not exhibit large-scale synteny with either rice or sorghum genomes but does contain multiple regions of microsynteny with these species. PMID:18508959

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

    PubMed

    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.

  17. 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

  18. 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…

  19. Enhancing GRASS data communication with videographic technology

    SciTech Connect

    Sullivan, R.G.; Gerdes, D.; Youngs, D.

    1992-07-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  20. Enhancing GRASS data communication with videographic technology

    SciTech Connect

    Sullivan, R.G. ); Gerdes, D.; Youngs, D. )

    1992-01-01

    Research at Argonne National Laboratory and the US Army Construction Engineering Research Laboratory has shown that computer videographic technology can be used to assist visualization and communication of GIS-generated geographic information. Videographic tools can be used to make results of GRASS analyses clear to decision-makers and to public interest groups, as well as to help GRASS users visualize geographic data more easily. Useful videographic visualization tools include graphic overlay of GRASS layers onto panchromatic images, allowing landscape features to be associated with GIS classifications; draping of GIS layers onto terrain models to create shaded relief maps; and incorporation of photographic imagery into GIS graphics. Useful videographic communications capabilities include convenient, direct interface to video formats, allowing incorporation of live video into GRASS graphics and output of GRASS graphics to video; convenient output of high-quality slides and prints; and enhanced labeling and editing of GRASS images. Conversion of GRASS imagery to standard videographic file formats also facilitates incorporation of GRASS images into other software programs, such as database and work-processing packages.

  1. 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. PMID:26254764

  2. 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.

  3. 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. PMID:26888207

  4. 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

  5. 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

  6. Influence of riparian vegetation on channel widening and subsequent contraction on a sand-bed stream since European settlement: Widden Brook, Australia

    NASA Astrophysics Data System (ADS)

    Erskine, Wayne; Keene, Annabelle; Bush, Richard; Cheetham, Michael; Chalmers, Anita

    2012-04-01

    Widden Brook in the Hunter Valley, Australia, was first settled by Europeans in 1831 and had widened substantially by the 1870s due to frequent floods during a flood-dominated regime impacting on highly disturbed banks whose riparian trees had been either ringbarked or cleared, and whose understorey had been grazed. Catastrophic floods in 1950 (many), two in August 1952 and one in February 1955 effected the final phase of channel widening at the onset of a second flood-dominated regime more than half a century after the initial widening. Contraction has been active since 1963 by a combination of five biogeomorphic processes. Firstly, rapid channel widening, migration and cutoffs totally reworked the pre-European floodplain and were followed by active floodplain formation. Initial bar formation was replaced by sand splay and overbank deposition which constructed a new floodplain and narrower channel. Secondly, overwidened channel segments that were produced by the catastrophic 1955 flood have contracted since 1963 by the formation of up to four bank-attached, discontinuous benches below the floodplain. Each bench has a bar nucleus of pebbly coarse sand overlain by stratified fine-medium sand and mud. Colonisation by River Sheoaks (Casuarina cunninghamiana subsp. cunninghamiana) or grasses (Cynodon dactylon, Paspalum distichum, Pennisetum clandestinum) is important in converting bars to benches. Thirdly, narrower segments which developed since 1963 have contracted by small-scale accretion on both banks. These deposits are steeply dipping, interbedded sand and mud trapped by stoloniferous and rhizomatous grasses (C. dactylon, P. distichum, P. clandestinum) which also rapidly stabilise the deposits. Fourthly, rare laterally migrating, small radius bends have contracted by recent point bar formation greatly exceeding cutbank recession rates. Point bar formation is controlled by secondary currents producing inclined stratified coarse sands without the influence of

  7. Bio-ethanol production through simultaneous saccharification and co-fermentation (SSCF) of a low-moisture anhydrous ammonia (LMAA)-pretreated napiegrass (Pennisetum purpureum Schumach).

    PubMed

    Yasuda, Masahide; Nagai, Hayato; Takeo, Keisuke; Ishii, Yasuyuki; Ohta, Kazuyoshi

    2014-01-01

    Efficient bio-ethanol production from napiegrass (Pennisetum purpureum Schumach) was investigated. A low-moisture anhydrous ammonia (LMAA)-pretreated napiegrass was subjected to simultaneous saccharification and co-fermentation (SSCF), which was performed at 36°C using Escherichia coli KO11, Saccharomyces cerevisiae, cellulase, and xylanase. It was found that use of xylanase as well as the LMAA-pretreatment was effective for the SSCF. After the SSCF for 96 h, the ethanol yield reached 74% of the theoretical yield based on the glucan (397 mg g(-1)) and xylan (214 mg g(-1)) occurring in dry powdered LMAA-pretreated napiergrass. PMID:26034662

  8. 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

  9. 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. PMID:23771285

  10. 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

  11. 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.

  12. 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

  13. 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)

  14. Temperate grass response to timing of grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing management has a significant impact on pasture growth. We determined how timing of grazing influences grass productivity, yield distribution, and persistence. Meadow fescue [Schedonorus pratensis (Huds.) P. Beauv.], orchardgrass (Dactylis glomerata L.), quackgrass [Elymus repens (L.) Gould...

  15. 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.

  16. 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. PMID:26791612

  17. 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.

  18. 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.

  19. 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

  20. 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. PMID:26241871

  1. 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.

  2. Phylogenetic niche conservatism in C4 grasses.

    PubMed

    Liu, Hui; Edwards, Erika J; Freckleton, Robert P; Osborne, Colin P

    2012-11-01

    Photosynthetic pathway is used widely to discriminate plant functional types in studies of global change. However, independent evolutionary lineages of C(4) grasses with different variants of C(4) photosynthesis show different biogeographical relationships with mean annual precipitation, suggesting phylogenetic niche conservatism (PNC). To investigate how phylogeny and photosynthetic type differentiate C(4) grasses, we compiled a dataset of morphological and habitat information of 185 genera belonging to two monophyletic subfamilies, Chloridoideae and Panicoideae, which together account for 90 % of the world's C(4) grass species. We evaluated evolutionary variance and covariance of morphological and habitat traits. Strong phylogenetic signals were found in both morphological and habitat traits, arising mainly from the divergence of the two subfamilies. Genera in Chloridoideae had significantly smaller culm heights, leaf widths, 1,000-seed weights and stomata; they also appeared more in dry, open or saline habitats than those of Panicoideae. Controlling for phylogenetic structure showed significant covariation among morphological traits, supporting the hypothesis of phylogenetically independent scaling effects. However, associations between morphological and habitat traits showed limited phylogenetic covariance. Subfamily was a better explanation than photosynthetic type for the variance in most morphological traits. Morphology, habitat water availability, shading, and productivity are therefore all involved in the PNC of C(4) grass lineages. This study emphasized the importance of phylogenetic history in the ecology and biogeography of C(4) grasses, suggesting that divergent lineages need to be considered to fully understand the impacts of global change on plant distributions. PMID:22569558

  3. Evolution of centromeric retrotransposons in grasses.

    PubMed

    Sharma, Anupma; Presting, Gernot G

    2014-06-01

    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

  4. 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

  5. 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.

  6. 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

  7. 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

  8. Molecular biomarkers for grass pollen immunotherapy.

    PubMed

    Popescu, Florin-Dan

    2014-03-26

    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.

  9. GRASSIUS: a platform for comparative regulatory genomics across the grasses.

    PubMed

    Yilmaz, Alper; Nishiyama, Milton Y; Fuentes, Bernardo Garcia; Souza, Glaucia Mendes; Janies, Daniel; Gray, John; Grotewold, Erich

    2009-01-01

    Transcription factors (TFs) are major players in gene regulatory networks and interactions between TFs and their target genes furnish spatiotemporal patterns of gene expression. Establishing the architecture of regulatory networks requires gathering information on TFs, their targets in the genome, and the corresponding binding sites. We have developed GRASSIUS (Grass Regulatory Information Services) as a knowledge-based Web resource that integrates information on TFs and gene promoters across the grasses. In its initial implementation, GRASSIUS consists of two separate, yet linked, databases. GrassTFDB holds information on TFs from maize (Zea mays), sorghum (Sorghum bicolor), sugarcane (Saccharum spp.), and rice (Oryza sativa). TFs are classified into families and phylogenetic relationships begin to uncover orthologous relationships among the participating species. This database also provides a centralized clearinghouse for TF synonyms in the grasses. GrassTFDB is linked to the grass TFome collection, which provides clones in recombination-based vectors corresponding to full-length open reading frames for a growing number of grass TFs. GrassPROMDB contains promoter and cis-regulatory element information for those grass species and genes for which enough data are available. The integration of GrassTFDB and GrassPROMDB will be accomplished through GrassRegNet as a first step in representing the architecture of grass regulatory networks. GRASSIUS can be accessed from www.grassius.org.

  10. 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...

  11. 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.

  12. 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...

  13. 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…

  14. 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…

  15. 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...

  16. 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

  17. 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.

  18. 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... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass... grasses listed in § 201.2(h). (a) Cereals: Agrotricum, barley, oat, rye, mountain rye, wheat,...

  19. 7 CFR 201.56-5 - Grass family, Poaceae (Gramineae).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Grass family, Poaceae (Gramineae). 201.56-5 Section... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass... grasses listed in § 201.2(h). (a) Cereals: Agrotricum, barley, oat, rye, mountain rye, wheat,...

  20. 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 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  1. 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 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  2. 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 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Grass family, Poaceae (Gramineae). 201.56-5 Section... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass... grasses listed in § 201.2(h). (a) Cereals: Agrotricum, barley, oat, rye, mountain rye, wheat,...

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Grass family, Poaceae (Gramineae). 201.56-5 Section... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass... grasses listed in § 201.2(h). (a) Cereals: Agrotricum, barley, oat, rye, mountain rye, wheat,...

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Grass family, Poaceae (Gramineae). 201.56-5 Section... ACT FEDERAL SEED ACT REGULATIONS Germination Tests in the Administration of the Act § 201.56-5 Grass... grasses listed in § 201.2(h). (a) Cereals: Agrotricum, barley, oat, rye, mountain rye, wheat,...

  6. 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 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT... Determining Coverage Using Value § 1437.310 Sea grass and sea oats. (a) Sea grass and sea oats are value...

  7. 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) ...

  8. 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.

  9. 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. PMID:9693274

  10. 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.

  11. 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

  12. Association of azospirillum with grass roots.

    PubMed

    Umali-Garcia, M; Hubbell, D H; Gaskins, M H; Dazzo, F B

    1980-01-01

    The association between grass roots and Azospirillum brasilense Sp 7 was investigated by the Fahraeus slide technique, using nitrogen-free medium. Young inoculated roots of pearl millet and guinea grass produced more mucilaginous sheath (mucigel), root hairs, and lateral roots than did uninoculated sterile controls. The bacteria were found within the mucigel that accumulated on the root cap and along the root axes. Adherent bacteria were associated with granular material on root hairs and fibrillar material on undifferentiated epidermal cells. Significantly fewer numbers of azospirilla attached to millet root hairs when the roots were grown in culture medium supplemented with 5 mM potassium nitrate. Under these growth conditions, bacterial attachment to undifferentiated epidermal cells was unaffected. Aseptically collected root exudate from pearl millet contained substances which bound to azospirilla and promoted their adsorption to the root hairs. This activity was associated with nondialyzable and proteasesensitive substances in root exudate. Millet root hairs adsorbed azospirilla in significantly higher numbers than cells of Rhizobium, Pseudomonas, Azotobacter, Klebsiella, or Escherichia. Pectolytic activities, including pectin transeliminase and endopolygalacturonase, were detected in pure cultures of A. brasilense when this species was grown in a medium containing pectin. These studies describe colonization of grass root surfaces by A. brasilense and provide a possible explanation for the limited colonization of intercellular spaces of the outer root cortex.

  13. Transfer of Cs-137 from grass and wilted grass silage to milk of dairy cows.

    PubMed

    Vreman, K; van der Struijs, T D; van den Hoek, J; Berende, P L; Goedhart, P W

    1989-09-01

    Deposition of radiocaesium from the Chernobyl reactor accident on the Netherlands made it possible to collect contaminated fresh grass and first cut wilted grass silage. These contaminated roughages were used in transfer experiments with lactating dairy cows to determine transfer coefficients and half-lives for Cs-137 in milk. The experimental design was based on three consecutive periods: a preliminary period to determine the background concentration of the isotope in milk, a contamination period to determine the magnitude of accumulation and finally a depletion period to measure the rate at which the activity concentration of Cs-137 in milk declined after continuous feeding. The average transfer coefficient (Fmilk) for cows fed on contaminated dried grass under steady-state conditions was 0.002 d/kg and for cows fed on slightly contaminated second cut fresh grass 0.006 d/kg. The highest transfer coefficients were obtained for cows fed on contaminated grass silage for 119 days, which also included the dry period of about two months. For the first five days after calving the Fmilk values varied from 0.0066 to 0.0091 d/kg. There were no significant differences in transfer coefficients between cows in early lactation (third month of lactation), cows in late lactation (the last month of the lactation period) and cows fed on both contaminated grass silage and uncontaminated maize silage simultaneously. Half-life values for the rate of decline of the isotope in milk during the depletion period were estimated on the basis of a mathematical model with two exponential components. These components were characterized by half-lives of 0.5 to 3.5 days and 10 to 46 days. PMID:2814441

  14. Transfer of Cs-137 from grass and wilted grass silage to milk of dairy cows.

    PubMed

    Vreman, K; van der Struijs, T D; van den Hoek, J; Berende, P L; Goedhart, P W

    1989-09-01

    Deposition of radiocaesium from the Chernobyl reactor accident on the Netherlands made it possible to collect contaminated fresh grass and first cut wilted grass silage. These contaminated roughages were used in transfer experiments with lactating dairy cows to determine transfer coefficients and half-lives for Cs-137 in milk. The experimental design was based on three consecutive periods: a preliminary period to determine the background concentration of the isotope in milk, a contamination period to determine the magnitude of accumulation and finally a depletion period to measure the rate at which the activity concentration of Cs-137 in milk declined after continuous feeding. The average transfer coefficient (Fmilk) for cows fed on contaminated dried grass under steady-state conditions was 0.002 d/kg and for cows fed on slightly contaminated second cut fresh grass 0.006 d/kg. The highest transfer coefficients were obtained for cows fed on contaminated grass silage for 119 days, which also included the dry period of about two months. For the first five days after calving the Fmilk values varied from 0.0066 to 0.0091 d/kg. There were no significant differences in transfer coefficients between cows in early lactation (third month of lactation), cows in late lactation (the last month of the lactation period) and cows fed on both contaminated grass silage and uncontaminated maize silage simultaneously. Half-life values for the rate of decline of the isotope in milk during the depletion period were estimated on the basis of a mathematical model with two exponential components. These components were characterized by half-lives of 0.5 to 3.5 days and 10 to 46 days.

  15. 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%.

  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. 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

  18. 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.

  19. Lactational performance of Jersey cows given Napier fodder (Pennisetum purpureum) with and without protein concentrates in the semi-humid tropics.

    PubMed

    Muinga, R W; Thorpe, W; Topps, J H

    1993-05-01

    Two experiments with 12 and 18 lactating Jersey cows respectively were carried out in the coastal semi-humid zone of Kenya to assess the performance arising from the feeding of chopped Napier fodder (Pennisetum purpureum) given ad libitum with and without one of three sources of protein; fishmeal, copra cake and freshly cut Leucaena (Leucaena leucocephala). Each source supplied approximately 300 g crude protein daily. Dry matter intakes of Napier fodder fed alone averaged 7.1 and 5.5 kg in Experiments 1 and 2 respectively. Additional protein did not affect Napier fodder intake, but total intakes of dry matter were higher for the cows receiving the protein supplements, differences which were significant (P < 0.05) in Experiment 2. Average daily milk production from cows fed Napier fodder alone was 6.4 and 4.2 kg in Experiments 1 and 2 respectively. The additional 300 g crude protein increased milk production by 1.0 to 1.6 kg/day, increases which, except that for fishmeal, were significant (P < 0.05). Weight losses of the cows were either reduced or changed to weight gains by the provision of protein. The results are assessed in relation to the energy and protein requirements for milk production.

  20. 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

  1. 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...

  2. 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...

  3. 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.

  4. 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...

  5. 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 ...

  6. Molecular understandings on 'the never thirsty' and apomictic Cenchrus grass.

    PubMed

    Syamaladevi, Divya P; Meena, S S; Nagar, R P

    2016-03-01

    The genus Cenchrus comprises around 25 species of 'bristle clade' grasses. Cenchrus ciliaris (buffel grass) is a hardy, perennial range grass that survives in poor sandy soils and limiting soil moisture conditions and, due to the very same reasons, this grass is one of the most prevalent fodder grasses of the arid and semi-arid regions. Most of the germplasms of Cenchrus produce seeds asexually through the process of apomeiosis. Therefore, the lack of sufficient sexual lines has hindered the crop improvement efforts in Cenchrus being confined to simple selection methods. Many attempts have been initiated in buffel grass to investigate the various molecular aspects such as genomic signatures of different species and genotypes, molecular basis of abiotic stress tolerance and reproductive performance. Even though it is an important fodder crop, molecular investigations in Cenchrus lack focus and the molecular information available on this grass is scanty. Cenchrus is a very good gene source for abiotic stress tolerance and apomixis studies. Biotechnological interventions in Cenchrus can help in crop improvement in Cenchrus as well as other crops through transgenic technology or marker assisted selection. To date no consolidated review on biotechnological interventions in Cenchrus grass has been published. Therefore we provide a thorough and in depth review on molecular research in Cenchrus focusing on molecular signatures of evolution, tolerance to abiotic stress and apomictic reproductive mechanism.

  7. 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...

  8. 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

  9. How Management of Grass Hedges Affects Their Erosion Reduction Potential

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grass hedges are specialized vegetative buffers effective in trapping sediment. Information is needed on how the effectiveness of grass hedges changes over time after planting, and in response to hedge clipping management. Erosion from natural rainfall was measured during thirteen years after establ...

  10. 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 ...

  11. 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...

  12. Molecular understandings on 'the never thirsty' and apomictic Cenchrus grass.

    PubMed

    Syamaladevi, Divya P; Meena, S S; Nagar, R P

    2016-03-01

    The genus Cenchrus comprises around 25 species of 'bristle clade' grasses. Cenchrus ciliaris (buffel grass) is a hardy, perennial range grass that survives in poor sandy soils and limiting soil moisture conditions and, due to the very same reasons, this grass is one of the most prevalent fodder grasses of the arid and semi-arid regions. Most of the germplasms of Cenchrus produce seeds asexually through the process of apomeiosis. Therefore, the lack of sufficient sexual lines has hindered the crop improvement efforts in Cenchrus being confined to simple selection methods. Many attempts have been initiated in buffel grass to investigate the various molecular aspects such as genomic signatures of different species and genotypes, molecular basis of abiotic stress tolerance and reproductive performance. Even though it is an important fodder crop, molecular investigations in Cenchrus lack focus and the molecular information available on this grass is scanty. Cenchrus is a very good gene source for abiotic stress tolerance and apomixis studies. Biotechnological interventions in Cenchrus can help in crop improvement in Cenchrus as well as other crops through transgenic technology or marker assisted selection. To date no consolidated review on biotechnological interventions in Cenchrus grass has been published. Therefore we provide a thorough and in depth review on molecular research in Cenchrus focusing on molecular signatures of evolution, tolerance to abiotic stress and apomictic reproductive mechanism. PMID:26601981

  13. 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.

  14. A comparative view of the evolution of grasses under domestication.

    PubMed

    Glémin, Sylvain; Bataillon, Thomas

    2009-01-01

    Crop grasses were among the first plants to be domesticated c. 12,000 yr ago, and they still represent the main staple crops for humans. During domestication, as did many other crops, grasses went through dramatic genetic and phenotypic changes. The recent massive increase in genomic data has provided new tools to investigate the genetic basis and consequences of domestication. Beyond the genetics of domestication, many aspects of grass biology, including their phylogeny and developmental biology, are also increasingly well studied, offering a unique opportunity to analyse the domestication process in a comparative way. Taking such a comparative point of view, we review the history of domesticated grasses and how domestication affected their phenotypic and genomic diversity. Considering recent theoretical developments and the accumulation of genetic data, we revisit more specifically the role of mating systems in the domestication process. We close by suggesting future directions for the study of domestication in grasses.

  15. 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.

  16. 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.

  17. Summer Dormancy in Perennial Temperate Grasses

    PubMed Central

    VOLAIRE, FLORENCE; NORTON, MARK

    2006-01-01

    • Background and Aims Dormancy has been extensively studied in plants which experience severe winter conditions but much less so in perennial herbaceous plants that must survive summer drought. This paper reviews the current knowledge on summer dormancy in both native and cultivated perennial temperate grasses originating from the Mediterranean Basin, and presents a unified terminology to describe this trait. • Scope Under severe drought, it is difficult to separate the responses by which plants avoid and tolerate dehydration from those associated with the expression of summer dormancy. Consequently, this type of endogenous (endo-) dormancy can be tested only in plants that are not subjected to moisture deficit. Summer dormancy can be defined by four criteria, one of which is considered optional: (1) reduction or cessation of leaf production and expansion; (2) senescence of mature foliage; (3) dehydration of surviving organs; and (4, optional) formation of resting organs. The proposed terminology recognizes two levels of summer dormancy: (a) complete dormancy, when cessation of growth is associated with full senescence of foliage and induced dehydration of leaf bases; and (b) incomplete dormancy, when leaf growth is partially inhibited and is associated with moderate levels of foliage senescence. Summer dormancy is expressed under increasing photoperiod and temperature. It is under hormonal control and usually associated with flowering and a reduction in metabolic activity in meristematic tissues. Dehydration tolerance and dormancy are independent phenomena and differ from the adaptations of resurrection plants. • Conclusions Summer dormancy has been correlated with superior survival after severe and repeated summer drought in a large range of perennial grasses. In the face of increasing aridity, this trait could be used in the development of cultivars that are able to meet agronomic and environmental goals. It is therefore important to have a better

  18. 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.

  19. 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.

  20. 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.

  1. Stability theory for the synchronized waving of marine grass

    NASA Astrophysics Data System (ADS)

    Singh, Ravi; Mahadevan, Amala; Mandre, Shreyas; Mahadevan, L. M.

    2014-11-01

    Synchronized waving of grass blades in the presence of fluid flow has been observed in cases such as wheat field in wind, marine grass in tidal currents. The synchronous motion can have important environmental and ecological impact via mixing of fluid due to waving. When the hydrodynamic and elastic time scales are well separated, this waving is thought to be due to Kelvin-Helmholtz instability resulting from an inflection point in the flow profile. We find that the inflection point is located near the tip of grass canopy. We extend the Orr-Sommerfeld equation for the stability of a shear flow to include a continuum mean-field approximation for the vegetation, thus capturing the essential ingredients for flow instability leading to coherent waving. Our linear stability analysis shows that the flow in presence of grass become unstable not only through a mechanism of Kelvin-Helmholtz instability but also through shear instability of flow above grass. We also find that flow with low submergence ratio of grass becomes unstable due to Kelvin-Helmholtz instability whereas flow high submergence ratio becomes unstable due to shear instability of flow above the grass. Numerical results demonstrating these instability mechanism will also be presented.

  2. Epichloë grass endophytes in sustainable agriculture.

    PubMed

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

    2016-01-01

    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. PMID:27249195

  3. 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

    2015-01-01

    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

  4. 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...

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Temperate Perennial Grass Response to Defoliation Height and Interval

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The frequency and extent to which temperate perennial grasses are defoliated influences their productivity and persistence. Field-grown tillers of meadow fescue (Festuca pratensis Huds.), orchardgrass (Dactylis glomerata L.), common quackgrass [Elymus repens (L.) Gould], and reed canarygrass (Phala...

  12. 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

  13. 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).

  14. Architectural Evolution and its Implications for Domestication in Grasses

    PubMed Central

    Doust, Andrew

    2007-01-01

    Background The cereal crops domesticated from grasses provide a large percentage of the calories consumed by humans. Domestication and breeding in individual cereals has historically occurred in isolation, although this is rapidly changing with comparative genomics of the sequenced or soon-to-be sequenced genomes of rice, sorghum, maize and Brachypodium. Genetic information transferred through genomic comparisons is helping our understanding of genetically less tractable crops such as the hexaploid wheats and polyploid sugarcane, as well as the approx. 10 000 species of wild grasses. In turn, phylogenetic analysis helps put our knowledge of the morphology of cereal crops into an evolutionary context. Grass Architecture Domestication often involves a change in the pattern and timing of branching, which affects both vegetative and inflorescence architecture, and ultimately yield. Cereal grasses exhibit two main forms of vegetative architecture: the pooid and erhartoid cereals such as wheat and rice have multiple basal tillers, while panicoid cereals such as maize, sorghum and the millets have few tillers or even only a single main stem. These differences are reflected in the differences between the wild species of pooid and some erhartoid grasses, which emphasize basal branching over axillary branching, and the panicoid grasses, where axillary branching is more frequently found. A combination of phylogenetic and genomic analysis is beginning to reveal the similarities and differences between different cereal crops, and relate these to the diversity of wild grasses to which they are related. Recent work on genes controlling branching emphasizes that developmental genetics needs to be viewed in both an evolutionary and ecological framework, if it is to be useful in understanding how morphology evolves. Increasingly, exploring the phylogenetic context of the crop grasses will suggest new ways to identify and create combinations of morphological traits that will best

  15. Female homogamety in grass carp (Ctenopharyngodon idella) determined by gynogenesis

    USGS Publications Warehouse

    Stanley, Jon G.

    1976-01-01

    Gynogenesis occurred in eggs of grass carp (Ctenopharyngodon idella) treated with X-irradiated milt from goldfish (Carassius auratus). Gynogenetic offspring were females, which indicates functional female homogamety in grass carp. Five of these gynogenetic fish were used as an egg source for a second generation of artificially gynogenetic fish. The percentage yield in this second generation was about the same as in the first, which suggests that the tendency to become diploid is not strongly heritable

  16. 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.

  17. Ellen R. Grass lecture: Back to the future: from grass roots to microchips.

    PubMed

    Drazkowski, Joseph F

    2011-06-01

    The study of the electroencephalogram (EEG) and other clinical neurophysiology (CNP) measurement tools has evolved over the last 70 years. In this evolutionary process, Ellen Grass and many professional technologists along the way have been instrumental in the translation of new developments in CNP technology to clinical utility. Technological developments in long-term EEG/video intensive care unit (ICU) monitoring, intraoperative monitoring, high frequency oscillation (HFO) recordings, automated signal analysis tools, seizure prediction devices, and the study of implanted intracranial recording and stimulation devices will improve our understanding of how the nervous system works. Improved understanding and translation of this evolving technology for improved patient care and outcomes remains the ultimate goal of such endeavors. Professional organizations such as the American Board of Registration of Electroencephalographic and Evoked Potential Technologists (ABRET) and the American Society of Electroneurodiagnostic Technologists (ASET) must continue to serve the CNP community and society to guide the application of this technology with an emphasis on providing information, guidelines on its use, and setting standards of professionalism. Any prior prediction of the demise of CNP technology has been greatly exaggerated. Quite the opposite has occurred, considering that the humble origins of vacuum tube powered Grass EEG machines will eventually yield to intracranial implanted microchip based recording and stimulation devices; the future appears bright for our profession.

  18. 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

  19. Mycorrhizal fungi affect root stele tissue in grasses.

    SciTech Connect

    Miller, R. M.; Hetrick, B. A. D.; Wilson, G. W. T.; Environmental Research; Northern Iowa Univ.; Kansas State Univ.

    1997-01-01

    Although arbuscular mycorrhizal symbiosis was initially believed to have little or no impact on root morphology, we now recognize that subtle changes do occur and that these changes may be of considerable consequence to host growth and nutrition, as well as functional growth strategy. In examining the stele and root diameters of C3 and C4 grasses, C4 grasses were demonstrated to have a significantly larger proportion of their fibrous roots occupied by stele tissue than do C3 grasses. In fact, functional growth strategy (C3 versus C4) was observed to be a relatively good predictor of stele area. Mycorrhizal fungi also influenced the amount of stele tissue, but the effect was not the same for both C3 and C4 grasses. The stele area of all C4 grasses except for Sorghastrum nutans was greater in the presence of mycorrhizal colonization. Among the C3 grasses, only Bromus inermis showed a significant increase, although Elymus cinereus and Lolium perenne displayed significant decreases in response to arbuscular mycorrhizal colonization. Changes in the stele area of the plant species were closely related to their responsiveness to mycorrhizal symbiosis and might in part explain both beneficial and detrimental responses of plants to mycorrhizae. An increase in stele circumference induced by mycorrhizae would allow for greater uptake and passage of water and nutrients to the vascular cylinder, and growth depressions could be a direct outcome of reduced stele circumference. Thus, differences in stele circumference represent a possible mechanism for mycorrhizal impacts on host plants. These findings indicate that structural differences among grasses are related to different functional capabilities and further emphasize the need for better integration of comparative anatomy and morphology procedures in the study of mycorrhizal symbiosis.

  20. [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

  1. [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

  2. 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

  3. Differences in grass pollen allergen exposure across Australia

    PubMed Central

    Beggs, Paul J.; Katelaris, Constance H.; Medek, Danielle; Johnston, Fay H.; Burton, Pamela K.; Campbell, Bradley; Jaggard, Alison K.; Vicendese, Don; Bowman, David M.J.S.; Godwin, Ian; Huete, Alfredo R.; Erbas, Bircan; Green, Brett J.; Newnham, Rewi M.; Newbigin, Ed; Haberle, Simon G.; Davies, Janet M.

    2015-01-01

    Objective Allergic rhinitis and allergic asthma are important chronic diseases posing serious public health issues in Australia with associated medical, economic, and societal burdens. Pollen are significant sources of clinically relevant outdoor aeroallergens, recognised as both a major trigger for, and cause of, allergic respiratory diseases. This study aimed to provide a national, and indeed international, perspective on the state of Australian pollen data using a large representative sample. Methods Atmospheric grass pollen concentration is examined over a number of years within the period 1995 to 2013 for Brisbane, Canberra, Darwin, Hobart, Melbourne, and Sydney, including determination of the ‘clinical’ grass pollen season and grass pollen peak. Results The results of this study describe, for the first time, a striking spatial and temporal variability in grass pollen seasons in Australia, with important implications for clinicians and public health professionals, and the Australian grass pollen-allergic community. Conclusions These results demonstrate that static pollen calendars are of limited utility and in some cases misleading. This study also highlights significant deficiencies and limitations in the existing Australian pollen monitoring and data. Implications Establishment of an Australian national pollen monitoring network would help facilitate advances in the clinical and public health management of the millions of Australians with asthma and allergic rhinitis. PMID:25648730

  4. 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

  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. PMID:26417095

  6. 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.

  7. [The textual research on the original plant of grass monkshood].

    PubMed

    Xie, Jin; Wang, De-Qun

    2012-05-01

    According to the literature review and field investigation, the traditional production areas of the herb grass monkshood are East China, Sichuan and its surroundings. The protophytes of grass monkshood in the east China area are mainly the Huangshan monkshood variant and truppelianum; but in the Sichuan area they are mainly aconite and aconitum hemsleyanum. The above belong to the aconitum of aconitum suby and tendril monkshood. They are the closest genetic relatives and the most evolutive groups as well as the most toxic groups. Local aconite was used as grass monkshood medicine in folk medicine but this happened only in part of the region and for a period of time. There were few records in literature in past dynasties and they would not have been able to be included in mainstream history. It is obviously different from the aconitum kusnezoffii which is stipulated in the pharmacopoeia in past ages. It is not in accordance with history to take kusnezoffii as certified quality grass monkshood and it also has some particular influence on the clinical use of grass monkshood. PMID:22883380

  8. 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.

  9. 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.

  10. 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.

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

    PubMed

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

    2014-01-01

    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.

  12. 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.

  13. 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.

  14. 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

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

    PubMed

    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

  16. 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.

  17. 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.

  18. An experimental study of flow around submerged grass vegetation

    NASA Astrophysics Data System (ADS)

    Lee, Julia; Mandre, Shreyas; Singh, Ravi

    2014-11-01

    Mixing of fluids through submerged vegetation caused by tidal currents facilitate various environmental and ecological transport processes. This fluid-vegetation interaction is believed to result from a Kelvin-Helmholtz instability from an inflection point in the flow profile. Recent studies suggest that flow in presence of grass can also become unstable due to shear instability of flow above the grass. We devise a two-dimensional lab scale analog of the fluid-vegetation interaction using ABS plastic filaments immersed in a soap film. We employ PIV of the surrounding flow to gain an understanding of the role of instabilities in the flow.

  19. Brachypodium distachyon: making hay with a wild grass.

    PubMed

    Opanowicz, Magdalena; Vain, Philippe; Draper, John; Parker, David; Doonan, John H

    2008-04-01

    Brachypodium distachyon is a wild grass with a short life cycle. Although it is related to small grain cereals such as wheat, its genome is only a fraction of the size. A draft genome sequence is currently available, and molecular and genetic tools have been developed for transformation, mutagenesis and gene mapping. Accessions collected from across its ancestral range show a surprising degree of phenotypic variation in many traits, including those implicated in domestication of the cereals. Thus, given its rapid cycling time and ease of cultivation, Brachypodium will be a useful model for investigating problems in grass biology. PMID:18343709

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

    DOE PAGESBeta

    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 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

  1. 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.

  2. 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...

  3. 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. ...

  4. Humidity critical for grass growth in warming climates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant growth responses to climate change might be confounded by multi-factor changes such as temperature and vapor pressure deficit (VPD). The growth and water loss of tall fescue (Festuca arundinaccea Schreb.), a cool season grass, was measured over 6 weeks with independent control of temperature a...

  5. 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.

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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…

  13. 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…

  14. 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.

  15. 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...

  16. 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)

  17. 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.

  18. Grass Roots Activism in the United States: Global Implications?

    ERIC Educational Resources Information Center

    Alger, Chadwick F.; Mendlovitz, Saul

    Interviews were conducted with 35 grass roots activists from middle-sized U.S. cities and small towns to learn about their perspectives and activities. No effort was made to obtain a representative sample of activists. The five main approaches to social change encountered were represented by members of the ideological and political left, by…

  19. 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...

  20. 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 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER ASSISTANCE...

  1. 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.

  2. 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, ...

  3. Fire Intensity and its Effects on Four Major Grass Species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fuel and fire conditions needed to cause grass mortality are largely unknown. Individual plants of Hesperostipa comata, Carex filifolia, Bouteloua gracilis, and Pascopyrum smithii were collected from rangeland, potted, and acclimated to greenhouse conditions. Plants were exposed to fire in 1-by-0...

  4. G.R.A.S.S. is Available

    ERIC Educational Resources Information Center

    Chapman, William Dan; Gambrell, C. B.

    1976-01-01

    Florida Technical University's approximately 11,000 students use its Generalized Registration and Sectioning System (GRASS), which provides on-line advanced and regular registration, on-line add/drop and late registration with instant invoice and class schedule printing. Description of system capabilities, notes on development, and samples of…

  5. Rainbows in the grass. II. Arbitrary diagonal incidence.

    PubMed

    Adler, Charles L; Lock, James A; Fleet, Richard W

    2008-12-01

    We consider external reflection rainbow caustics due to the reflection of light from a pendant droplet where the light rays are at an arbitrary angle with respect to the horizontal. We compare this theory to observation of glare spots from pendant drops on grass; we also consider the potential application of this theory to the determination of liquid surface tension. PMID:19037345

  6. 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 ...

  7. 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...

  8. 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...

  9. 26 CFR 56.4911-6 - Records of lobbying and grass roots expenditures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 17 2010-04-01 2010-04-01 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 26 CFR 56.4911-3 - Expenditures for direct and/or grass roots lobbying communications.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 17 2012-04-01 2012-04-01 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...

  15. 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...

  16. 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 ...

  17. 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.

  18. Characterization of grass carp spleen transcriptome during GCRV infection.

    PubMed

    Xu, B H; Zhong, L; Liu, Q L; Xiao, T Y; Su, J M; Chen, K J; Wang, H Q; Dai, Y J; Chen, J

    2016-01-01

    The aim of the study was to investigate the grass carp hemorrhagic infection pathway and its key-related genes. Grass carp reovirus (GCRV) might cause hemorrhagic disease in grass carps. Healthy grass carp fingerlings (N = 60) were divided into control and infected groups. Fish in the control group were intraperitoneally (ip) injected with 0.6% fish physiological saline; the infected group received 5,000,000 50% tissue culture infective doses of GCRV 873 standard strain, a double-stranded RNA (dsRNA) virus strain, ip, in 0.5 mL. Illumina HiSeqTM 2000 was used for transcriptome sequencing, and real-time polymerase chain reaction (PCR) used to detect complement factors II (C2), III (C3), and V (C5); profibrinolysin (PLG); and coagulation factor II (F2) expression. A total of 2,722,223 reads were detected in the control group, and 2,751,111 in the infected group. Among 11,023 unigenes obtained after transcriptome assembly, 10,021 unigenes were significantly differentially expressed. Gene ontology and KEGG analysis, a collection of databases dealing with genomes and biological pathways, were performed to classify unigenes into functional categories, to understand gene function and identify regulatory pathways. Real-time PCR analysis showed that C2, C3, C5, PLG, and F2 expression levels were down-regulated, confirming results of pathway-enrichment analysis. This is the first application of high-throughput sequencing technology to investigate the in vivo effects of GCRV, on genes and pathways involved in the immune response to infection in grass carp. PMID:27173223

  19. 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.

  20. 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.

  1. 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....

  2. 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....

  3. 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....

  4. 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....

  5. 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....

  6. 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 ...

  7. Emerging technologies advancing forage and turf grass genomics.

    PubMed

    Kopecký, David; Studer, Bruno

    2014-01-01

    Grassland is of major importance for agricultural production and provides valuable ecosystem services. Its impact is likely to rise in changing socio-economic and climatic environments. High yielding forage grass species are major components of sustainable grassland production. Understanding the genome structure and function of grassland species provides opportunities to accelerate crop improvement and thus to mitigate the future challenges of increased feed and food demand, scarcity of natural resources such as water and nutrients, and high product qualities. In this review, we will discuss a selection of technological developments that served as main drivers to generate new insights into the structure and function of nuclear genomes. Many of these technologies were originally developed in human or animal science and are now increasingly applied in plant genomics. Our main goal is to highlight the benefits of using these technologies for forage and turf grass genome research, to discuss their potentials and limitations as well as their relevance for future applications. PMID:24309540

  8. 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.

  9. Study of "napier grass" delignification for production of cellulosic derivatives.

    PubMed

    de Araújo Morandim-Giannetti, Andreia; Albuquerque, Tiago Santos; de Carvalho, Renata Kobal Campos; Araújo, Ramires Menezes Silva; Magnabosco, Rodrigo

    2013-01-30

    Recently, much research on the evaluation of new cellulose sources has been developed. In this context, a promising source is "napier grass", which contains 30.40% lignin, 36.34% cellulose, and 34.12% hemicellulose. In this work, conditions for the delignification of "napier grass" in the laboratory were studied by using calcium oxide (CaO) and hydrogen peroxide (H(2)O(2)). The best pulping conditions were 9.00% CaO for a period of 2.73 h, which resulted in 74.99% delignification and 66.58% cellulose. The best conditions for the bleaching process were pH 12 and hydrogen peroxide at concentration of 4.2% for 6h, at a temperature of 40 °C, which gave 90.98% delignification and 99.21% cellulose. The analyses were performed by using weight percent.

  10. 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.

  11. Emerging technologies advancing forage and turf grass genomics.

    PubMed

    Kopecký, David; Studer, Bruno

    2014-01-01

    Grassland is of major importance for agricultural production and provides valuable ecosystem services. Its impact is likely to rise in changing socio-economic and climatic environments. High yielding forage grass species are major components of sustainable grassland production. Understanding the genome structure and function of grassland species provides opportunities to accelerate crop improvement and thus to mitigate the future challenges of increased feed and food demand, scarcity of natural resources such as water and nutrients, and high product qualities. In this review, we will discuss a selection of technological developments that served as main drivers to generate new insights into the structure and function of nuclear genomes. Many of these technologies were originally developed in human or animal science and are now increasingly applied in plant genomics. Our main goal is to highlight the benefits of using these technologies for forage and turf grass genome research, to discuss their potentials and limitations as well as their relevance for future applications.

  12. 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.

  13. 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. PMID:27367811

  14. 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.

  15. Mozambican grass seed consumption during the Middle Stone Age.

    PubMed

    Mercader, Julio

    2009-12-18

    The role of starchy plants in early hominin diets and when the culinary processing of starches began have been difficult to track archaeologically. Seed collecting is conventionally perceived to have been an irrelevant activity among the Pleistocene foragers of southern Africa, on the grounds of both technological difficulty in the processing of grains and the belief that roots, fruits, and nuts, not cereals, were the basis for subsistence for the past 100,000 years and further back in time. A large assemblage of starch granules has been retrieved from the surfaces of Middle Stone Age stone tools from Mozambique, showing that early Homo sapiens relied on grass seeds starting at least 105,000 years ago, including those of sorghum grasses.

  16. 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

  17. 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.

  18. 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

  19. 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).

  20. 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.

  1. 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.

  2. 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 = / .

  3. Molecular phylogeny of the fungi of the Iceman's grass clothing.

    PubMed

    Rollo, F; Sassaroli, S; Ubaldi, M

    1995-08-01

    To investigate the origin of the fungal hyphae that cover the grass clothing (cloak, boots) found near the neolithic mummy known as the Tyrolean Iceman, two radiocarbon-dated samples of grass were submitted to DNA extraction. The DNA was then PCR amplified using, respectively, primers specific for the region containing the internal transcribed spacers and the 5.8s rDNA (ITS), and primers specific for an approximately 600-bp long fragment of the nuclear small-subunit ribosomal DNA (SSU rDNA) repeat units of eukaryotes. The amplification products were cloned and sequenced. Sequence analysis of 20 individual ITS clones and of ten SSU rDNA clones indicated that three types of fungal DNA can be extracted from the grass. Phylogenetic analyses, using 5.8s and SSU rDNA fungal reference sequences from EMBL and GenBank databases, suggest that the DNAs come, respectively, from a psychrophilic basidiomycetous yeast, phylogenetically close to Leucosporidium scottii, and from two ascomycetes, one of which is possibly related to the Eurotiales.

  4. Microwave backscattering and emission model for grass canopies

    SciTech Connect

    Saatchi, S.S. ); Le Vine, D.M. . Goddard Space Flight Center); Lang, R.H. . Dept. of Electrical and Computer Engineering)

    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.

  5. 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.

  6. 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.

  7. High-density grass carp stocking effects on a reservoir invasive plant and water quality

    USGS Publications Warehouse

    Garner, A. Brad; Kwak, Thomas J.; Manuel, Kenneth L.; Barwick, D. Hugh

    2013-01-01

    Stocking grass carp [Ctenopharyngodon idella (Valenciennes)] is a commonly applied technique to control nuisance aquatic vegetation in reservoirs. Factors that influence the degree of aquatic vegetation control are fish stocking density, regional climate, abundance and species composition of the aquatic plant community, and relative grass carp feeding preferences for plant species. We evaluated high-density grass carp stocking in a southeastern U.S. reservoir for control of parrot-feather [Myriophyllum aquaticum (Vell) Verdc.], an invasive aquatic plant that is not preferentially consumed by grass carp and the associated effects on water quality. Lookout Shoals Lake, a 528-ha piedmont North Carolina reservoir, was stocked with triploid grass carp at a density of 100 fish per vegetated hectare. Parrot-feather biomass in the lake was significantly reduced three months after grass carp stocking, compared to biomass in in-situ exclosures. During the second year after grass carp stocking, parrot-feather biomass in the lake compared to biomass in in-situ exclosures indicated continued control, but unexplained lack of growth within most experimental exclosures precluded biomass analyses. Increases in ambient water chlorophyll a, reactive phosphorus, and nitrate-nitrite concentrations were measured after grass carp stocking. The biological significance of observed changes in water chemistry and long-term effects on lake biota remain undetermined. Our results demonstrate that intensive grass carp stocking can control an invasive aquatic plant that is not preferentially consumed by grass carp and reveal associated changes in water quality.

  8. 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.

  9. Clinical and immunological effects of immunotherapy with alum-absorbed grass allergoid in grass-pollen-induced hay fever.

    PubMed

    Pastorello, E A; Pravettoni, V; Incorvaia, C; Mambretti, M; Franck, E; Wahl, R; Zanussi, C

    1992-08-01

    A double-blind, placebo-controlled study of immunotherapy was conducted in 19 patients with grass-pollen hay fever to evaluate the efficacy and safety of a formalinized depot grass allergoid. The patients were assessed before and during IT by clinical (symptom-medication scores during the grass- pollen season, specific nasal and skin reactivity) and immunological (specific IgE, IgG, IgG1 and IgG4 antibodies) parameters. High doses of grass allergoid, corresponding to a cumulative pre-seasonal dosage of 46,050 PNU, were administered, with only one systemic reaction. The actively treated patients had significantly lower symptom-medication scores than placebo (p less than 0.01) during the month of May and showed a significant decrease in specific skin (p less than 0.01) and nasal (p less than 0.05) reactivity, and a significant early increase in specific IgE (p less than 0.01), IgG (p less than 0.0005), IgG1 (p less than 0.001) and IgG4 (p less than 0.05), with a subsequent decrease of IgE and IgG1. No differences were detected in any of these parameters in the placebo group. A correlation was found between high IgG4/IgG1 ratio and the specific skin reactivity decrease (r = 0.691, p less than 0.05), whereas a high IgG4/IgG1 ratio was associated with higher symptom-medication scores (r = 0.654, p less than 0.05). Possible explanations of these apparent discrepancies are proposed.

  10. 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. PMID:26780256

  11. 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

  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. 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.

  14. 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.

  15. 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.

  16. 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

  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. PMID:27551380

  18. 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.

  19. 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.

  20. 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. PMID:27656171

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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).

  8. 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). PMID:26712135

  9. Dinosaur coprolites and the early evolution of grasses and grazers.

    PubMed

    Prasad, Vandana; Strömberg, Caroline A E; Alimohammadian, Habib; Sahni, Ashok

    2005-11-18

    Silicified plant tissues (phytoliths) preserved in Late Cretaceous coprolites from India show that at least five taxa from extant grass (Poaceae) subclades were present on the Indian subcontinent during the latest Cretaceous. This taxonomic diversity suggests that crown-group Poaceae had diversified and spread in Gondwana before India became geographically isolated. Other phytoliths extracted from the coprolites (from dicotyledons, conifers, and palms) suggest that the suspected dung producers (titanosaur sauropods) fed indiscriminately on a wide range of plants. These data also make plausible the hypothesis that gondwanatherian mammals with hypsodont cheek teeth were grazers. PMID:16293759

  10. 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.

  11. 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. PMID:18246856

  12. 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.

  13. 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. PMID:26972738

  14. 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

  15. 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. PMID:21279407

  16. Competition for water between deep- and shallow-rooted grasses

    SciTech Connect

    Healy, J.L.; Black, R.A. ); Link, S.O. )

    1994-06-01

    Competition between root systems of neighboring plants may be altered by seasonal variation in precipitation and soil moisture. Competitive effects of a deep-rooted, perennial grass, Pseudoroegneria spicata, on a shallow-rooted, perennial grass, Poa sandbergii, were monitored over two growing seasons by isolating the root system of P. sandbergii individuals within PVC tubes and comparing plant and soil characteristics to controls. When isolated for the entire growing season, P. sandbergii continued vegetative growth three weeks longer and later season soil water content was significantly greater than controls. Differences in soil water content were greatest between 30 and 50cm, below P. sandbergii's typical rooting depth. Flowering phenology was unchanged. When plants were isolated late in the season, treated plants showed more negative predown xylem pressure potential the morning after isolatron. Compared to controls, soil water content was reduced the day after tube insertion. These immediate effects on plant and soil water status may be due to removal of water supplied nightly by hydraulic lift.

  17. 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.

  18. 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.

  19. Melon sensitivity shares allergens with Plantago and grass pollens.

    PubMed

    García Ortiz, J C; Cosmes Martín, P; Lopez-Asunolo, A

    1995-03-01

    Possible associations between allergy to pollen and that to food allergens were studied in 262 patients sensitized to pollen. Forty-four patients (16.7%) showed some allergic symptoms after testing with fruits and vegetables, melon being the food most frequently involved (24 patients), followed by sunflower seed (12 patients). Skin testing was done by the prick method with natural fruit or vegetable, and also with commercial food extracts. We found in our region that the distribution of sensitivity to pollens in the group of patients with allergy to fruits or vegetables does not coincide with the prevalence in pollen-allergic subjects in general, since in the first group--subjects allergic to food--there was a major prevalence of allergy to Plantago (P < 0.01). In particular, in the group of subjects allergic to melon, the prevalence of sensitivity to grass and especially to Plantago was larger than in pollen-allergic subjects in general (P < 0.05 and P < 0.001, respectively). The use of fresh food produced better results than commercial extracts. A positive skin test to fresh melon closely correlated with positive CAP results. CAP inhibition experiments were carried out, and we found that Dactylis and Plantago extracts inhibited the binding of the melon-positive pool to solid-phase melon. The results suggest the existence of common antigenic epitopes in melon and Plantago pollen, and in melon and grass pollen.

  20. Biogas from grass silage - Measurements and modeling with ADM1.

    PubMed

    Koch, Konrad; Lübken, Manfred; Gehring, Tito; Wichern, Marc; Horn, Harald

    2010-11-01

    Mono fermentation of grass silage without the addition of manure was performed over a period of 345days under mesophilic conditions (38 degrees C). A simulation study based on the IWA Anaerobic Digestion Model No. 1 (ADM1) was done in order to show its applicability to lignocellulosic biomass. Therefore, the influent was fractioned by established fodder analysis (Weender analysis and van Soest method). ADM1 was modified with a separate compound of inert decay products similar to the approach of Activated Sludge Model No. 1 (ASM1). Furthermore, a function, which described the influence of solids on the process of hydrolysis, has been integrated to reproduce reliable ammonium concentrations. The model was calibrated by using the modified Nash-Sutcliffe coefficient to evaluate simulation quality. It was possible to fit observed data by changing only hydrogen inhibition constants and the maximum acetate uptake rate. The extended ADM1 model showed good agreement with measurements and was suitable for modeling anaerobic digestion of grass silage.

  1. Prairie grass establishment on calcareous reclaimed mine soil.

    PubMed

    Thorne, Mark; Cardina, John

    2011-01-01

    Reclaimed Appalachian surface mined lands have difficulty in sustaining native deciduous forest communities. Establishing prairie communities could increase ecosystem function; however, a native model system does not exist. We evaluated establishment of 15 North American prairie grasses as monocultures on reclaimed mine soil in southeast Ohio in four randomized complete blocks planted May 2005 and 2006. Population density was assessed 30 d after planting (30 DAP) and in October of the planting year (YR1) and second year following planting (YR2) and expressed as percentage of viable seeds sown (PVSS). Canopy cover of nonnative species reestablishing in the plots was measured in 2007. Eastern gamagrass ( L.) population was >50 PVSS in all censuses. Western wheatgrass [ (Rydb.) A. Löve] was initially 7 PVSS at 30 DAP, but increased to 154 PVSS by YR2 from rhizomes spreading into gaps. Big bluestem ( Vitman) was 7 PVSS at 30 DAP and 4 PVSS at YR2. Blue grama [ (Willd. ex Kunth) Lag. ex Griffiths] and sideoats grama [ (Michx.) Torr.] did not survive past YR1. Gaps left from poor stand establishment were primarily recolonized by nonnative Kentucky bluegrass ( L.) in the 2005 planting and birdsfoot trefoil ( L.) in the 2006 planting, but was least in eastern gamagrass and tall dropseed [ (P. Beauv.) Kunth]. This research demonstrates the potential for increasing diversity and species richness on mine soil habitats with regionally native grasses that could increase functional quality through ecological resilience.

  2. 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.

  3. 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

  4. 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...

  5. Image analysis of anatomical traits in stalk transections of maize and other grasses

    DOE PAGESBeta

    Heckwolf, Sven; Heckwolf, Marlies; Kaeppler, Shawn M.; de Leon, Natalia; Spalding, Edgar P

    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.

  6. Field drying rate differences amoung cool-season grasses harvested for hay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Making high-quality, cool-season grass hay is a challenge, due to the field drying time needed to reach the appropriate moisture content and the high probability of rain in the spring when hay is typically produced. This study was conducted to determine if cool-season grasses with different yield po...

  7. 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...

  8. Anti-Insect Properties of Grass Fungal Endophytes for Plant Resistance to Insects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many temperate grass species host Epichloë and Neotyphodium endophytic fungi that produce alkaloids with anti-mammalian and anti-insect properties. Ergot and lolitrem alkaloid production by endophyte-infected (E+) grasses can have deleterious effects on grazing livestock, whereas insecticidal alkal...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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.

  14. The eating quality of meat of steers fed grass and/or concentrates.

    PubMed

    French, P; O'Riordan, E G; Monahan, F J; Caffrey, P J; Mooney, M T; Troy, D J; Moloney, A P

    2001-04-01

    The objective was to determine, relative to animals expressing their full potential for carcass growth, the impact on meat quality of increasing carcass growth of grazing steers by supplementing with concentrates or by increasing grass supply. Sixty-six continental (Limousin and Charolais) crossbred steers (567 kg) were assigned to one of six diets: (1) 18 kg grass dry matter (DM); (2) 18 kg grass DM grass and 2.5 kg concentrate; (3) 18 kg grass DM and 5 kg concentrate; (4) 6 kg grass DM and 5 kg concentrate; (5) 12 kg grass DM and 2.5 kg concentrate; or (6) concentrates daily. Animals were slaughtered after an average of 95 days. Samples of the M. longissmus dorsi (LD) were collected at the 8-9th rib interface and subjected to sensory analysis and to other assessments of quality following 2, 7, or 14 days aging. Carcass weight gain averaged 360, 631, 727, 617, 551 and 809 g/day for treatments 1 to 6, respectively. There was no difference between diets for colour, Warner-Bratzler shear force (WBSF) or any sensory attribute of the LD. WBSF was negatively correlated with (P<0.05) carcass growth rate (-0.31) but only a small proportion of the variation in meat quality between animals could be attributed to diet pre-slaughter or carcass fatness. It is concluded that high carcass growth can be achieved on a grass-based diet without a deleterious effect on meat quality. PMID:22061710

  15. Grass Hosts Harbor More Diverse Isolates of Puccinia striiformis Than Cereal Crops.

    PubMed

    Cheng, P; Chen, X M; See, D R

    2016-04-01

    Puccinia striiformis causes stripe rust on cereal crops and many grass species. However, it is not clear whether the stripe rust populations on grasses are able to infect cereal crops and how closely they are related to each other. In this study, 103 isolates collected from wheat, barley, triticale, rye, and grasses in the United States were characterized by virulence tests and simple sequence repeat (SSR) markers. Of 69 pathotypes identified, 41 were virulent on some differentials of wheat only, 10 were virulent on some differentials of barley only, and 18 were virulent on some differentials of both wheat and barley. These pathotypes were clustered into three groups: group one containing isolates from wheat, triticale, rye, and grasses; group two isolates were from barley and grasses; and group three isolates were from grasses and wheat. SSR markers identified 44 multilocus genotypes (MLGs) and clustered them into three major molecular groups (MG) with MLGs in MG3 further classified into three subgroups. Isolates from cereal crops were present in one or more of the major or subgroups, but not all, whereas grass isolates were present in all of the major and subgroups. The results indicate that grasses harbor more diverse isolates of P. striiformis than the cereals.

  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. 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 ...

  18. 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...

  19. Soil sterilization alters interactions between the native grass Bouteloua gracilis and invasive Bromus tectorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The invasive grass Bromus tectorum negatively impacts grassland communities throughout the western U.S. We asked whether soil biota growing in association with a native grass (Bouteloua gracilis) increase growth and competitive ability of Bromus, and whether responses vary between soils collec...

  20. 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 ...

  1. Endogenous toxins and mycotoxins in forage grasses and their effects on livestock.

    PubMed

    Cheeke, P R

    1995-03-01

    Plant toxins are the chemical defenses of plants against herbivory. Grasses have relatively few intrinsic toxins, relying more on growth habit to survive defoliation and endophytic fungal toxins as chemical defenses. Forage grasses that contain intrinsic toxins include Phalaris spp. (tryptamine and carboline alkaloids), sorghums (cyanogenic glycosides), and tropical grasses containing oxalates and saponins. Toxic effects of these grasses include neurological damage (Phalaris staggers), hypoxia (sudangrass), saponin-induced photosensitization (Brachiaria and Panicum spp.), and bone demineralization (oxalate-containing grasses). Endophytic toxins in grasses include ergot alkaloids in tall fescue and tremorgens (e.g., lolitrem B) in perennial ryegrass. Lolitrems cause neurological effects, producing the ryegrass staggers syndrome. Annual ryegrass toxicosis is caused by corynetoxins, which are chemically similar to tunicamycin antibiotics. Corynetoxins are produced by Clavibacter bacteria that parasitize a nematode, Anguina agrostis, that may infect annual ryegrass. Corynetoxins inhibit glycoprotein synthesis, causing defective formation of various blood components of the reticulo-endothelial system. Another mycotoxin in ryegrass is sporidesmin, which causes liver damage and secondary photosensitization (facial eczema). Fusarium toxins such as zearalenone and trichothecenes also occur in forage grasses. Kikuyugrass poisoning results in severe damage to the ruminal epithelium and omasal mucosa, and neurological signs. The causative agent, which may be associated with army worm predation of the grass, has not been identified. The properties and significance of these toxins are reviewed.

  2. 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...

  3. 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...

  4. Grass Hosts Harbor More Diverse Isolates of Puccinia striiformis Than Cereal Crops.

    PubMed

    Cheng, P; Chen, X M; See, D R

    2016-04-01

    Puccinia striiformis causes stripe rust on cereal crops and many grass species. However, it is not clear whether the stripe rust populations on grasses are able to infect cereal crops and how closely they are related to each other. In this study, 103 isolates collected from wheat, barley, triticale, rye, and grasses in the United States were characterized by virulence tests and simple sequence repeat (SSR) markers. Of 69 pathotypes identified, 41 were virulent on some differentials of wheat only, 10 were virulent on some differentials of barley only, and 18 were virulent on some differentials of both wheat and barley. These pathotypes were clustered into three groups: group one containing isolates from wheat, triticale, rye, and grasses; group two isolates were from barley and grasses; and group three isolates were from grasses and wheat. SSR markers identified 44 multilocus genotypes (MLGs) and clustered them into three major molecular groups (MG) with MLGs in MG3 further classified into three subgroups. Isolates from cereal crops were present in one or more of the major or subgroups, but not all, whereas grass isolates were present in all of the major and subgroups. The results indicate that grasses harbor more diverse isolates of P. striiformis than the cereals. PMID:26667189

  5. 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 = 548, mean age = 53.5…

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. Relationship between heavy metal concentrations in soils and grasses of roadside farmland in Nepal.

    PubMed

    Yan, Xuedong; Zhang, Fan; Zeng, Chen; Zhang, Man; Devkota, Lochan Prasad; Yao, Tandong

    2012-09-04

    Transportation activities can contribute to accumulation of heavy metals in roadside soil and grass, which could potentially compromise public health and the environment if the roadways cross farmland areas. Particularly, heavy metals may enter the food chain as a result of their uptake by roadside edible grasses. This research was conducted to investigate heavy metal (Cu, Zn, Cd, and Pb) concentrations in roadside farmland soils and corresponding grasses around Kathmandu, Nepal. Four factors were considered for the experimental design, including sample type, sampling location, roadside distance, and tree protection. A total of 60 grass samples and 60 topsoil samples were collected under dry weather conditions. The Multivariate Analysis of Variance (MANOVA) results indicate that the concentrations of Cu, Zn, and Pb in the soil samples are significantly higher than those in the grass samples; the concentrations of Cu and Pb in the suburban roadside farmland are higher than those in the rural mountainous roadside farmland; and the concentrations of Cu and Zn at the sampling locations with roadside trees are significantly lower than those without tree protection. The analysis of transfer factor, which is calculated as the ratio of heavy-metal concentrations in grass to those in the corresponding soil, indicates that the uptake capabilities of heavy metals from soil to grass is in the order of Zn > Cu > Pb. Additionally, it is found that as the soils' heavy-metal concentrations increase, the capability of heavy-metal transfer to the grass decreases, and this relationship can be characterized by an exponential regression model.

  11. [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

  12. [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

  13. 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...

  14. An ecohydrological framework for grass displacement by woody plants in savannas

    NASA Astrophysics Data System (ADS)

    Yu, Kailiang; D'Odorico, Paolo

    2014-03-01

    During the past several decades, woody plants have been encroaching into grasslands around the world. This transition in plant dominance is often explained as a state shift in bistable ecosystem dynamics induced by fire-vegetation feedbacks. These feedbacks occur when woody plants are able to displace grasses because of their better access to soil water and light. On the other hand, grasses can displace woody plants because of their ability to increase fire frequency and of the higher susceptibility of woody plants to fire-induced mortality. In this study, we present an ecohydrological framework to investigate the displacement of grasses by woody plants. Considering the effect of lateral root spread and of soil water and light limitations, we found that woody plant encroachment can substantially suppress grass production even without the presence of grazers. Bistable dynamics emerge as a result of the grass-fire feedback for a wide range of rainfall conditions, fire susceptibility, and woody plant growth rates.

  15. Sweet grass protection against oxidative stress formation in the rat brain.

    PubMed

    Łuczaj, Wojciech; Jarocka-Karpowicz, Iwona; Bielawska, Katarzyna; Skrzydlewska, Elżbieta

    2015-02-01

    The aims of this study were to investigate the influences of sweet grass on chronic ethanol-induced oxidative stress in the rat brain. Chronic ethanol intoxication decreased activities and antioxidant levels resulting in enhanced lipid peroxidation. Administration of sweet grass solution to ethanol-intoxicated rats partially normalized the activity activities of Cu,Zn-superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, as well as levels of reduced glutathione and vitamins C, E, and A. Sweet grass also protected unsaturated fatty acids (arachidonic and docosahexaenoic) from oxidations and decreased levels of lipid peroxidation products: 4-hydroxynonenal, isoprostanes, and neuroprostanes. The present in vivo study confirms previous in vitro data demonstrating the bioactivity of sweet grass and suggests a possible role for sweet grass in human health protection from deleterious consequences associated with oxidative stress formation.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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

  4. A grass-fire cycle eliminates an obligate-seeding tree in a tropical savanna.

    PubMed

    Bowman, David M J S; MacDermott, Harry J; Nichols, Scott C; Murphy, Brett P

    2014-11-01

    A grass-fire cycle in Australian tropical savannas has been postulated as driving the regional decline of the obligate-seeding conifer Callitris intratropica and other fire-sensitive components of the regional flora and fauna, due to proliferation of flammable native grasses. We tested the hypothesis that a high-biomass invasive savanna grass drives a positive feedback process where intense fires destroy fire-sensitive trees, and the reduction in canopy cover facilitates further invasion by grass. We undertook an observational and experimental study using, as a model system, a plantation of C. intratropica that has been invaded by an African grass, gamba (Andropogon gayanus) in the Northern Territory, Australia. We found that high grass biomass was associated with reduced canopy cover and restriction of foliage to the upper canopy of surviving stems, and mortality of adult trees was very high (>50%) even in areas with low fuel loads (1 t·ha(-1)). Experimental fires, with fuel loads >10 t·ha(-1), typical of the grass-invasion front, caused significant mortality due to complete crown scorch. Lower fuel loads cause reduced canopy cover through defoliation of the lower canopy. These results help explain how increases in grass biomass are coupled with the decline of C. intratropica throughout northern Australia by causing a switch from litter and sparse perennial grass fuels, and hence low-intensity surface fires, to heavy annual grass fuel loads that sustain fires that burn into the midstorey. This study demonstrates that changes in fuel type can alter fire regimes with substantial knock-on effects on the biota. PMID:25505543

  5. 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.

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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

  12. 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

  13. Inter-sexual competition in a dioecious grass.

    PubMed

    Mercer, Charlene A; Eppley, Sarah M

    2010-11-01

    Spatial segregation of the sexes (SSS) occurs in many dioecious angiosperms, but little data are available on the fitness advantages, if any, for males and females. We examined whether reciprocally transplanted male and female seedlings of Distichlis spicata, a dioecious grass species that exhibits extreme SSS, differed in their responses to microhabitats and competition treatments. Plants grown without conspecific competitors grew equally well in both male- or female-majority habitats, suggesting that male and female plants do not have differential resource needs at the juvenile life-history stage. However, plants subject to intra-sexual competition were significantly larger than plants subject to inter-sexual competition, suggesting that niche partitioning may occur in D. spicata.

  14. 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.

  15. Ontogenetic development of adipose tissue in grass carp (Ctenopharyngodon idellus).

    PubMed

    Liu, Pin; Ji, Hong; Li, Chao; Tian, Jingjing; Wang, Yifei; Yu, Ping

    2015-08-01

    To investigate the adipose tissue development process during the early stages of grass carp (Ctenopharyngodon idellus) development, samples were collected from fertilized eggs to 30 days post-fertilization (dpf) of fish. Paraffin and frozen sections were taken to observe the characteristics of adipocytes in vivo by different staining methods, including hematoxylin and eosin (H&E), Oil red O, and BODIPY. The expression of lipogenesis-related genes of the samples at different time points was detected by real-time qPCR. In addition, protein expression level of peroxisome proliferator-activated receptors γ (PPAR γ) was detected by immunohistochemistry. The results showed that the neutral lipid droplets accumulated first in the hepatocytes of 14-dpf fish larvae, and visceral adipocytes appeared around the hepatopancreas on 16 dpf. As grass carp grew, the adipocytes increased in number and spread to other tissues. In 20-dpf fish larvae, the intestine was observed to be covered by adipose tissue. However, there was no significant change in the average size (30.40-40.01 μm) of adipocytes during this period. Accordingly, the gene expression level of PPAR γ and CCAAT/enhancer-binding proteins α (C/EBP α) was significantly elevated after fertilization for 12 days (p < 0.05), but C/EBP α declined at 20 dpf. Expression of lipoprotein lipase (LPL) increased from 2 to 16 dpf and then declined. In addition, immunoreaction of PPAR γ was positive on hepatocytes after fertilization for 15 days. These results implied that the early developmental stage of adipose tissue is caused by active recruitment of adipocytes as opposed to hypertrophy of the cell. In addition, our study indicated that lipogenesis-related genes might regulate the ongoing development of adipose tissue.

  16. 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. PMID:24467906

  17. 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.

  18. Is the Grass Always Greener? Comparing the Environmental Impact of Conventional, Natural and Grass-Fed Beef Production Systems

    PubMed Central

    Capper, Judith L.

    2012-01-01

    Simple Summary The environmental impact of three beef production systems was assessed using a deterministic model. Conventional beef production (finished in feedlots with growth-enhancing technology) required the fewest animals, and least land, water and fossil fuels to produce a set quantity of beef. The carbon footprint of conventional beef production was lower than that of either natural (feedlot finished with no growth-enhancing technology) or grass-fed (forage-fed, no growth-enhancing technology) systems. All beef production systems are potentially sustainable; yet the environmental impacts of differing systems should be communicated to consumers to allow a scientific basis for dietary choices. Abstract This study compared the environmental impact of conventional, natural and grass-fed beef production systems. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per 1.0 × 109 kg of hot carcass weight beef in conventional (CON), natural (NAT) and grass-fed (GFD) production systems. Production systems were modeled using characteristic management practices, population dynamics and production data from U.S. beef production systems. Increased productivity (slaughter weight and growth rate) in the CON system reduced the cattle population size required to produce 1.0 × 109 kg of beef compared to the NAT or GFD system. The CON system required 56.3% of the animals, 24.8% of the water, 55.3% of the land and 71.4% of the fossil fuel energy required to produce 1.0 × 109 kg of beef compared to the GFD system. The carbon footprint per 1.0 × 109 kg of beef was lowest in the CON system (15,989 × 103 t), intermediate in the NAT system (18,772 × 103 t) and highest in the GFD system (26,785 × 103 t). The challenge to the U.S beef industry is to communicate differences in system environmental impacts to facilitate informed dietary choice. PMID:26486913

  19. 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.

  20. Convergent and Contingent Community Responses to Grass Source and Dominance During Prairie Restoration Across a Longitudinal Gradient

    NASA Astrophysics Data System (ADS)

    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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Genome-wide analysis of syntenic gene deletion in the grasses.

    PubMed

    Schnable, James C; Freeling, Michael; Lyons, Eric

    2012-01-01

    The grasses, Poaceae, are one of the largest and most successful angiosperm families. Like many radiations of flowering plants, the divergence of the major grass lineages was preceded by a whole-genome duplication (WGD), although these events are not rare for flowering plants. By combining identification of syntenic gene blocks with measures of gene pair divergence and different frequencies of ancient gene loss, we have separated the two subgenomes present in modern grasses. Reciprocal loss of duplicated genes or genomic regions has been hypothesized to reproductively isolate populations and, thus, speciation. However, in contrast to previous studies in yeast and teleost fishes, we found very little evidence of reciprocal loss of homeologous genes between the grasses, suggesting that post-WGD gene loss may not be the cause of the grass radiation. The sets of homeologous and orthologous genes and predicted locations of deleted genes identified in this study, as well as links to the CoGe comparative genomics web platform for analyzing pan-grass syntenic regions, are provided along with this paper as a resource for the grass genetics community.

  11. Silicon, endophytes and secondary metabolites as grass defenses against mammalian herbivores

    PubMed Central

    Huitu, Otso; Forbes, Kristian M.; Helander, Marjo; Julkunen-Tiitto, Riitta; Lambin, Xavier; Saikkonen, Kari; Stuart, Peter; Sulkama, Sini; Hartley, Sue

    2014-01-01

    Grasses have been considered to primarily employ tolerance in lieu of defense in mitigating damage caused by herbivory. Yet a number of mechanisms have been identified in grasses, which may deter feeding by grazers. These include enhanced silicon uptake, hosting of toxin-producing endophytic fungi and induction of secondary metabolites. While these mechanisms have been individually studied, their synergistic responses to grazing, as well as their effects on grazers, are poorly known. A field experiment was carried out in 5 × 5 m outdoor enclosures to quantify phytochemical changes of either endophyte-infected (E+) or endophyte-free (E-) meadow fescue (Schedonorus pratensis) in response to medium intensity (corresponding with densities of ca. 1200 voles/ha for 5 weeks during 3 months) or heavy intensity (ca. 1200 voles/ha for 8 weeks during 3 months) grazing by a mammalian herbivore, the field vole (Microtus agrestis). A laboratory experiment was then conducted to evaluate the effects of endophyte infection status and grazing history of the grass diet on vole performance. As predicted, grazing increased foliar silicon content, by up to 13%. Grazing also increased foliar levels of phosphorous and several phenolic compounds, most notably those of the flavonols isorhamnetin-diglycoside and rhamnetin derivative. Silicon concentrations were consistently circa 16% higher in E+ grasses than in E-grasses, at all levels of grazing. Similarly, concentrations of chlorogenic acid derivative were found to be consistently higher in E+ than in E- grasses. Female voles maintained on heavily grazed grasses suffered higher mortality rates in the laboratory than female voles fed ungrazed grass, regardless of endophyte infection status. Our results conclusively demonstrate that, in addition to tolerance, grasses employ multi-tiered, effective defenses against mammalian grazers. PMID:25278951

  12. 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.

  13. 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

  14. GRASS: a server for the graphical representation and analysis of structures.

    PubMed Central

    Nayal, M.; Hitz, B. C.; Honig, B.

    1999-01-01

    GRASS (Graphical Representation and Analysis of Structures Server), a new web-based server, is described. GRASS exploits many of the features of the GRASP program and is designed to provide interactive molecular graphics and quantitative analysis tools with a simple interface over the World-Wide Web. Using GRASS, it is now possible to view many surface features of biological macromolecules on either standard workstations used in macromolecular analysis or personal computers. The result is a World-Wide Web-based, platform-independent, easily used tool for macromolecular visualization and structure analysis. PMID:10091670

  15. 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

  16. 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.

  17. 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

  18. 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

  19. Responses of plankton communities to the introduction of grass carp into some Georgia ponds

    USGS Publications Warehouse

    Terrell, T.T.

    1982-01-01

    Net plankton community structure and numbers were studied in soft-water, acidic ponds containing aquatic macrophytes, after introduction of the herbivorous grass carp (Ctenopharyngodon idella). The plankton communities in ponds with grass carp consisted of significantly fewer individuals, genera, and orders than did the communities in control ponds. Expected shifts from desirable to undesirable species of plankton did not occur. These results demonstrate that plankton blooms are not an inevitable result of stocking grass carp, and support the suggestion that macrophytes may be especially significant in nutrient cycling in soft-water, acidic systems.

  20. 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

  1. 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

  2. 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

  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. 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 ...

  5. History of introductions and governmental involvement in promoting the use of grass, silver, and bighead carps

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous natural resource agency and media reports have alleged that Asian carps were introduced into the wild through escapes from commercial fish farms. This presentation chronologically traces the introductions of Asian carps (grass carp Ctenopharyngodon idella, silver carp Hypophthalmichthys mol...

  6. Transcriptome profiling of grass carp (Ctenopharyngodon idellus) infected with Aeromonas hydrophila.

    PubMed

    Yang, Ying; Yu, Hui; Li, Hua; Wang, Anli

    2016-04-01

    Aeromonas hydrophila is the causative pathogen of intestinal hemorrhage which has caused great economic loss in grass carp aquaculture. In order to understand the immunological response of grass carp to infection by A. hydrophila, the transcriptomic profiles of the spleens from infected and non-infected grass carp groups were obtained using HiSeq™ 2500 (Illumina). An average of 63 million clean reads per library was obtained, and approximately 80% of these genes were successfully mapped to the reference genome. A total of 1591 up-regulated and 530 down-regulated genes were identified. Eight immune-related categories involving 105 differently expressed genes were scrutinized. 16 of the differently expressed genes involving immune response were further validated by qRT-PCR. Our results provide valuable information for further analysis of the mechanisms of grass carp defense against A. hydrophila invasion.

  7. 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

  8. 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.

  9. 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

  10. Hydraulic Lift As a Determinant of Tree-Grass Coexistence on Savannas

    NASA Astrophysics Data System (ADS)

    Yu, K.; D'Odorico, P.

    2014-12-01

    The coexistence of woody plants and grasses in savannas is determined by a complex set of interacting factors, including resource availability and disturbance. Existing theories explaining coexistence focus on competitive relations or disturbances preventing the system from attaining a state with complete grass or tree dominance. The effect of hydraulic lift on interactions between woody plants and grasses and the dynamics of savanna ecosystems remains poorly understood. Here, we develop a mechanistic model to investigate the role of hydraulic lift on the stability of savannas. The model accounts both for competition for soil water in the shallow soil layer and fire-induced disturbance. We find that hydraulic lift expands the parameter range in which savannas are stable at the expense of woodlands. Our study shows that hydraulic lift can be an important mechanism responsible for coexistence of woody plants and grasses in savannas.

  11. Nitrogen fertilizer management impact on dry matter yield of warm-season grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial warm-season grasses are being studied extensively as lignocellulosic herbaceous bioenergy feedstocks as they exhibit numerous ecosystem benefits. Nitrogen (N) fertilizer management and harvesting management are considered as critical management practices which effects on both the dry matte...

  12. The chemical control of Shorgum halepense (Johnson grass) in soybean culture in the Danube meadow.

    PubMed

    Poienaru, S; Sarpe, N; Sarpe, I

    2005-01-01

    Soybean cultures, especially those from the Danube Meadow, are very strongly infested with Johnson grass, which causes big damages, by the reduction of production with 40-85%, depending on the infestation degree. Before the synthesis of special herbicides for Johnson grass control, this species was controlled by practicing deep tilling, repeated operations with the disk, and, after the sprouting of soy plants, by mechanical and manual hoeings. In the Danube Waterside, the lack of labour force for the manual hoeing is very sharp. For this reason, it was generalized the enlarged use of herbicides for annual weed control (monocotyledonous and dicotyledonous), including Johnson grass. For the control of Johnson grass species, in the conditions of the Danube Meadow, the best results were obtained with the herbicides Fusilade Super, Targa Super, Agil and Select, and for the control of annual dicotyledonous species, with the herbicide Pivot 100LC.

  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. Contamination rates and antimicrobial resistance in bacteria isolated from "grass-fed" labeled beef products.

    PubMed

    Zhang, Jiayi; Wall, Samantha K; Xu, Li; Ebner, Paul D

    2010-11-01

    Grass-fed and organic beef products make up a growing share of the beef market in the United States. While processing, animal handling, and farm management play large roles in determining the safety of final beef products, grass-fed beef products are often marketed as safer alternatives to grain-finished beef products based on the potential effects of all-forage diets on host microbiota. We conducted a series of experiments examining bacterial contamination rates in 50 beef products labeled as "grass-fed" versus 50 conventionally raised retail beef products. Coliform concentrations did not differ between conventional and grass-fed beef (conventional: 2.6 log(10) CFU/mL rinsate; grass-fed: 2.7 log(10) CFU/mL rinsate). The percentages of Escherichia coli positive samples did not differ between the two groups (44% vs. 44%). Enterococcus spp. were frequently isolated from both grass-fed beef products (44%) and conventional beef products (62%; p = 0.07). No Salmonella or E. coli O157:H7 isolates were recovered from any of the meat samples. Enterococcus spp. isolates from conventional beef were more frequently resistant to daptomycin and linezolid (p < 0.05). Resistance to some antimicrobials (e.g., chloramphenicol, erythromycin, flavomycin, penicillin, and tetracyline) was high in Enterococcus spp. isolated from both conventional and grass-fed beef. There were no differences in the percentages of antimicrobial resistant E. coli isolates between the two groups. Taken together, these data indicate that there are no clear food safety advantages to grass-fed beef products over conventional beef products.

  16. Invasive Andropogon gayanus (gamba grass) is an ecosystem transformer of nitrogen relations in Australian savanna.

    PubMed

    Rossiter-Rachor, N A; Setterfield, S A; Douglas, M M; Hutley, L B; Cook, G D; Schmidt, S

    2009-09-01

    Invasion by the African grass Andropogon gayanus is drastically altering the understory structure of oligotrophic savannas in tropical Australia. We compared nitrogen (N) relations and phenology of A. gayanus and native grasses to examine the impact of invasion on N cycling and to determine possible reasons for invasiveness of A. gayanus. Andropogon gayanus produced up to 10 and four times more shoot phytomass and root biomass, with up to seven and 2.5 times greater shoot and root N pools than native grass understory. These pronounced differences in phytomass and N pools between A. gayanus and native grasses were associated with an altered N cycle. Most growth occurs in the wet season when, compared with native grasses, dominance of A. gayanus was associated with significantly lower total soil N pools, lower nitrification rates, up to three times lower soil nitrate availability, and up to three times higher soil ammonium availability. Uptake kinetics for different N sources were studied with excised roots of three grass species ex situ. Excised roots of A. gayanus had an over six times higher-uptake rate of ammonium than roots of native grasses, while native grass Eriachne triseta had a three times higher uptake rate of nitrate than A. gayanus. We hypothesize that A. gayanus stimulates ammonification but inhibits nitrification, as was shown to occur in its native range in Africa, and that this modification of the soil N cycle is linked to the species' preference for ammonium as an N source. This mechanism could result in altered soil N relations and could enhance the competitive superiority and persistence of A. gayanus in Australian savannas. PMID:19769102

  17. Relationship between Heavy Metal Concentrations in Soils and Grasses of Roadside Farmland in Nepal

    PubMed Central

    Yan, Xuedong; Zhang, Fan; Zeng, Chen; Zhang, Man; Devkota, Lochan Prasad; Yao, Tandong

    2012-01-01

    Transportation activities can contribute to accumulation of heavy metals in roadside soil and grass, which could potentially compromise public health and the environment if the roadways cross farmland areas. Particularly, heavy metals may enter the food chain as a result of their uptake by roadside edible grasses. This research was conducted to investigate heavy metal (Cu, Zn, Cd, and Pb) concentrations in roadside farmland soils and corresponding grasses around Kathmandu, Nepal. Four factors were considered for the experimental design, including sample type, sampling location, roadside distance, and tree protection. A total of 60 grass samples and 60 topsoil samples were collected under dry weather conditions. The Multivariate Analysis of Variance (MANOVA) results indicate that the concentrations of Cu, Zn, and Pb in the soil samples are significantly higher than those in the grass samples; the concentrations of Cu and Pb in the suburban roadside farmland are higher than those in the rural mountainous roadside farmland; and the concentrations of Cu and Zn at the sampling locations with roadside trees are significantly lower than those without tree protection. The analysis of transfer factor, which is calculated as the ratio of heavy-metal concentrations in grass to those in the corresponding soil, indicates that the uptake capabilities of heavy metals from soil to grass is in the order of Zn > Cu > Pb. Additionally, it is found that as the soils’ heavy-metal concentrations increase, the capability of heavy-metal transfer to the grass decreases, and this relationship can be characterized by an exponential regression model. PMID:23202679

  18. Stimulation of Spermiation by Human Chorionic Gonadotropin and Carp Pituitary Extract in Grass Puffer, Takifugu niphobles

    PubMed Central

    Goo, In Bon; Park, In-Seok; Gil, Hyun Woo; Im, Jae Hyun

    2015-01-01

    Spermiation was stimulated in the mature grass puffer, Takifugu niphobles, with an injection of human chorionic gonadotropin (HCG) or carp pituitary extract (CPE). Spermatocrit and sperm density were reduced, but milt production was increased in both the HCG and CPE treatment groups relative to those in the control group (P <0.05). These results should be useful for increasing the fertilization efficiency in grass puffer breeding programs. PMID:26973977

  19. 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.

  20. Molecular Evolution of Hypoallergenic Hybrid Proteins for Vaccination against Grass Pollen Allergy

    PubMed Central

    Linhart, Birgit; Focke-Tejkl, Margarete; Weber, Milena; Narayanan, Meena; Neubauer, Angela; Mayrhofer, Hannes; Blatt, Katharina; Lupinek, Christian; Valent, Peter

    2015-01-01

    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. PMID:25786690

  1. A molecular identification system for grasses: a novel technology for forensic botany.

    PubMed

    Ward, J; Peakall, R; Gilmore, S R; Robertson, J

    2005-09-10

    Our present inability to rapidly, accurately and cost-effectively identify trace botanical evidence remains the major impediment to the routine application of forensic botany. Grasses are amongst the most likely plant species encountered as forensic trace evidence and have the potential to provide links between crime scenes and individuals or other vital crime scene information. We are designing a molecular DNA-based identification system for grasses consisting of several PCR assays that, like a traditional morphological taxonomic key, provide criteria that progressively identify an unknown grass sample to a given taxonomic rank. In a prior study of DNA sequences across 20 phylogenetically representative grass species, we identified a series of potentially informative indels in the grass mitochondrial genome. In this study we designed and tested five PCR assays spanning these indels and assessed the feasibility of these assays to aid identification of unknown grass samples. We confirmed that for our control set of 20 samples, on which the design of the PCR assays was based, the five primer combinations produced the expected results. Using these PCR assays in a 'blind test', we were able to identify 25 unknown grass samples with some restrictions. Species belonging to genera represented in our control set were all correctly identified to genus with one exception. Similarly, genera belonging to tribes in the control set were correctly identified to the tribal level. Finally, for those samples for which neither the tribal or genus specific PCR assays were designed, we could confidently exclude these samples from belonging to certain tribes and genera. The results confirmed the utility of the PCR assays and the feasibility of developing a robust full-scale usable grass identification system for forensic purposes.

  2. Relationships among absorbents on the reduction of grass silage effluent and silage quality.

    PubMed

    Fransen, S C; Strubi, F J

    1998-10-01

    Effluent from grass silage is a threat to water quality and a loss of valuable forage nutrients from dairy farms. Absorbents potentially reduce effluent loss when weather conditions are not ideal for field wilting. The objective was to determine the effectiveness of various absorbents at reducing silage effluent. First-harvest, direct-cut, perennial grass forage was ensiled with and without absorbents in medium-sized experimental silos for 3 consecutive yr. Silos contained 4.54 kg of grass and one of the following feed quality absorbents: 10% rolled barley, 10% dried and pelleted beet pulp, or alfalfa cubes at 10, 20, or 30%. Nonfeed quality absorbents used were 1% starch grafter polymer, 1% bentonite clay, and 10% newspaper. Silage from direct-harvest control forage produced the highest effluent losses, but the wilting of grass prior to ensiling or the mixing of grass with 30% alfalfa cubes nearly eliminated effluent. Silage pH was lowest when rolled barley or beet pulp was used as the absorbent and was highest for wilted grass. Silage dry matter was increased by wilting and by the use of barley, beet pulp, newspapers, or alfalfa cubes as absorbents. The addition of 10% newspaper greatly reduced in vitro dry matter digestibility and crude protein. Increased water-soluble carbohydrate concentrations were found for silage from grass forage treated with rolled barley, beet pulp, or alfalfa cubes prior to ensiling. Although bentonite clay and newspapers reduced effluent losses, greater water-soluble carbohydrate losses were found for these treatments compared with the direct control. Alfalfa cubes were found to be effective absorbents and did not reduce grass silage quality.

  3. [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.

  4. Invasive Andropogon gayanus (gamba grass) is an ecosystem transformer of nitrogen relations in Australian savanna.

    PubMed

    Rossiter-Rachor, N A; Setterfield, S A; Douglas, M M; Hutley, L B; Cook, G D; Schmidt, S

    2009-09-01

    Invasion by the African grass Andropogon gayanus is drastically altering the understory structure of oligotrophic savannas in tropical Australia. We compared nitrogen (N) relations and phenology of A. gayanus and native grasses to examine the impact of invasion on N cycling and to determine possible reasons for invasiveness of A. gayanus. Andropogon gayanus produced up to 10 and four times more shoot phytomass and root biomass, with up to seven and 2.5 times greater shoot and root N pools than native grass understory. These pronounced differences in phytomass and N pools between A. gayanus and native grasses were associated with an altered N cycle. Most growth occurs in the wet season when, compared with native grasses, dominance of A. gayanus was associated with significantly lower total soil N pools, lower nitrification rates, up to three times lower soil nitrate availability, and up to three times higher soil ammonium availability. Uptake kinetics for different N sources were studied with excised roots of three grass species ex situ. Excised roots of A. gayanus had an over six times higher-uptake rate of ammonium than roots of native grasses, while native grass Eriachne triseta had a three times higher uptake rate of nitrate than A. gayanus. We hypothesize that A. gayanus stimulates ammonification but inhibits nitrification, as was shown to occur in its native range in Africa, and that this modification of the soil N cycle is linked to the species' preference for ammonium as an N source. This mechanism could result in altered soil N relations and could enhance the competitive superiority and persistence of A. gayanus in Australian savannas.

  5. 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. PMID:26003429

  6. 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

  7. Functional associations of floret and inflorescence traits among grass species.

    PubMed

    Friedman, Jannice; Harder, Lawrence D

    2005-11-01

    The aerodynamics of wind pollination selects for an intimate relation between form and function in anemophilous plants. Inflorescence architecture and floral morphology vary extensively within the Poaceae, but the functional implication of this variation remains largely unknown. Here we quantify associations between floret, culm, and inflorescence characteristics for 25 grass species in Kananaskis, Alberta, Canada, and consider whether different architectures may implement unique mechanisms to aid pollination. The species cluster into four categories defined by all combinations of floret size (small vs. large) and inflorescence architecture (compact vs. diffuse). Species differed significantly for all 18 traits that we measured, with 12 traits differing only between floret-size classes, three differing only between inflorescence types, and three differing among both (independently or by an interaction). Based on these morphological associations, we discuss the aerodynamic and functional consequences of each category for wind pollination. The independence of inflorescence and floral traits has probably allowed exploration of all possible combinations of inflorescence architecture and floret size during the evolution of the Poaceae. PMID:21646103

  8. Evolution of herbicide resistance mechanisms in grass weeds.

    PubMed

    Matzrafi, Maor; Gadri, Yaron; Frenkel, Eyal; Rubin, Baruch; Peleg, Zvi

    2014-12-01

    Herbicide resistant weeds are becoming increasingly common, threatening global food security. Here, we present BrIFAR: a new model system for the functional study of mechanisms of herbicide resistance in grass weeds. We have developed a large collection of Brachypodium accessions, the BrI collection, representing a wide range of habitats. Wide screening of the responses of the accessions to four major herbicide groups (PSII, ACCase, ALS/AHAS and EPSPS inhibitors) identified 28 herbicide-resistance candidate accessions. Target-site resistance to PSII inhibitors was found in accessions collected from habitats with a known history of herbicide applications. An amino acid substitution in the psbA gene (serine264 to glycine) conferred resistance and also significantly affected the flowering and shoot dry weight of the resistant accession, as compared to the sensitive accession. Non-target site resistance to ACCase inhibitors was found in accessions collected from habitats with a history of herbicide application and from a nature reserve. In-vitro enzyme activity tests and responses following pre-treatment with malathion (a cytochrome-P450 inhibitor) indicated sensitivity at the enzyme level, and give strong support to diclofop-methyl and pinoxaden enhanced detoxification as NTS resistance mechanism. BrIFAR can promote better understanding of the evolution of mechanisms of herbicide resistance and aid the implementation of integrative management approaches for sustainable agriculture.

  9. Evolution of herbicide resistance mechanisms in grass weeds.

    PubMed

    Matzrafi, Maor; Gadri, Yaron; Frenkel, Eyal; Rubin, Baruch; Peleg, Zvi

    2014-12-01

    Herbicide resistant weeds are becoming increasingly common, threatening global food security. Here, we present BrIFAR: a new model system for the functional study of mechanisms of herbicide resistance in grass weeds. We have developed a large collection of Brachypodium accessions, the BrI collection, representing a wide range of habitats. Wide screening of the responses of the accessions to four major herbicide groups (PSII, ACCase, ALS/AHAS and EPSPS inhibitors) identified 28 herbicide-resistance candidate accessions. Target-site resistance to PSII inhibitors was found in accessions collected from habitats with a known history of herbicide applications. An amino acid substitution in the psbA gene (serine264 to glycine) conferred resistance and also significantly affected the flowering and shoot dry weight of the resistant accession, as compared to the sensitive accession. Non-target site resistance to ACCase inhibitors was found in accessions collected from habitats with a history of herbicide application and from a nature reserve. In-vitro enzyme activity tests and responses following pre-treatment with malathion (a cytochrome-P450 inhibitor) indicated sensitivity at the enzyme level, and give strong support to diclofop-methyl and pinoxaden enhanced detoxification as NTS resistance mechanism. BrIFAR can promote better understanding of the evolution of mechanisms of herbicide resistance and aid the implementation of integrative management approaches for sustainable agriculture. PMID:25443832

  10. Mono fermentation of grass silage by means of loop reactors.

    PubMed

    Koch, Konrad; Wichern, Marc; Lübken, Manfred; Horn, Harald

    2009-12-01

    A loop reactor was operated for mono fermentation of grass silage without manure addition under mesophilic conditions (38 degrees C). An averaged specific biogas production of 0.50 m(N)(3) per kg volatile solids (VS) with a methane concentration of 52% at an organic loading rate of up to 3.5 kg(VS)/(m(3) d) was obtained. The retention time varied from 440 days at 1.0 kg(VS)/(m(3) d) to 50 days at 3.5 kg(VS)/(m(3) d). The degradation level was more than 60% based on VS and 75% based on COD. The first-order hydrolysis rate constant of the process was estimated to be 0.6 d(-1). Despite the relative high ammonium concentration of up to 4 g/l, the system worked stable for an operation period of 310 days. In particular the TS content in the fermenter was found to be a key parameter and should not exceed 12% in order to avoid instabilities.

  11. Infection of Brachypodium distachyon with selected grass rust pathogens.

    PubMed

    Ayliffe, Michael; Singh, Davinder; Park, Robert; Moscou, Matthew; Pryor, Tony

    2013-08-01

    The model temperate grass Brachypodium distachyon is considered a nonhost for wheat rust diseases caused by Puccinia graminis f. sp. tritici, P. triticina, and P. striiformis. Up to 140 Brachypodium accessions were infected with these three rust species, in addition to P. graminis ff. spp. avena and phalaridis. Related B. distachyon lines showed similar cytological nonhost resistance (NHR) phenotypes, and an inverse relationship between P. graminis f. sp. tritici and P. striiformis growth was observed in many lines, with accessions that allowed the most growth of P. graminis f. sp. tritici showing the least P. striiformis development and vice versa. Callose deposition patterns during infection by all three rust species showed similarity to the wheat basal defense response while cell death that resulted in autofluorescence did not appear to be a major component of the defense response. Infection of B. distachyon with P. graminis f. sp. avena and P. graminis f. sp. phalaridis produced much greater colonization, indicating that P. graminis rusts with Poeae hosts show greater ability to infect B. distachyon than those with Triticeae hosts. P. striiformis infection of progeny from two B. distachyon families demonstrated that these NHR phenotypes are highly heritable and appear to be under relatively simple genetic control, making this species a powerful tool for elucidating the molecular basis of NHR to cereal rust pathogens.

  12. Extreme genetic diversity in asexual grass thrips populations.

    PubMed

    Fontcuberta García-Cuenca, A; Dumas, Z; Schwander, T

    2016-05-01

    The continuous generation of genetic variation has been proposed as one of the main factors explaining the maintenance of sexual reproduction in nature. However, populations of asexual individuals may attain high levels of genetic diversity through within-lineage diversification, replicate transitions to asexuality from sexual ancestors and migration. How these mechanisms affect genetic variation in populations of closely related sexual and asexual taxa can therefore provide insights into the role of genetic diversity for the maintenance of sexual reproduction. Here, we evaluate patterns of intra- and interpopulation genetic diversity in sexual and asexual populations of Aptinothrips rufus grass thrips. Asexual A. rufus populations are found throughout the world, whereas sexual populations appear to be confined to few locations in the Mediterranean region. We found that asexual A. rufus populations are characterized by extremely high levels of genetic diversity, both in comparison with their sexual relatives and in comparison with other asexual species. Migration is extensive among asexual populations over large geographic distances, whereas close sexual populations are strongly isolated from each other. The combination of extensive migration with replicate evolution of asexual lineages, and a past demographic expansion in at least one of them, generated high local clone diversities in A. rufus. These high clone diversities in asexual populations may mimic certain benefits conferred by sex via genetic diversity and could help explain the extreme success of asexual A. rufus populations. PMID:26864612

  13. Intrapopulation sex ratio variation in the salt grass Distichlis spicata.

    PubMed

    Eppley, S M; Stanton, M L; Grosberg, R K

    1998-11-01

    ABSTRACT In many dioecious plant populations, males and females appear to be spatially segregated, a pattern that is difficult to explain given its potentially high costs. However, in asexually propagating species, spatial segregation of the sexes may be indistinguishable from superficially similar patterns generated by random establishment of a few genets followed by extensive clonal spread and by gender-specific differences in rates of clonal spread. In populations where a significant fraction of individuals are not flowering and gender cannot be assigned to this fraction, apparent spatial segregation of the sexes may be due to differential flowering between the sexes. We confirm reports that flowering ramets of the clonal, perennial grass Distichlis spicata are spatially segregated by sex. We extend these studies in two fundamental ways and demonstrate that this species exhibits true spatial segregation of the sexes. First, using RAPD markers, we estimated that at least 50% of ramets in patches with biased sex ratios represent distinct genotypes. Second, we identified a RAPD marker linked to female phenotype (eliminating the possibility that gender is environmentally determined) and used it to show that the majority of patches exhibit significantly biased sex ratios for both ramets and genets, regardless of flowering status.

  14. Grass plants bind, retain, uptake and transport infectious prions

    PubMed Central

    Pritzkow, Sandra; Morales, Rodrigo; Moda, Fabio; Khan, Uffaf; Telling, Glenn C.; Hoover, Edward; Soto, Claudio

    2015-01-01

    Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here we analyzed the binding and retention of infectious prion protein (PrPSc) to plants. Small quantities of PrPSc contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrPSc for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease. PMID:25981035

  15. How cereal grass shoots perceive and respond to gravity

    NASA Technical Reports Server (NTRS)

    Kaufman, P. B.; Brock, T. G.; Song, I.; Rho, Y. B.; Ghosheh, N. S.

    1987-01-01

    The leaf-sheath pulvinus of grasses presents a unique system for studying gravitropism, primarily because of its differences from other organs. The mature pulvinus is a discrete organ specialized for gravitropism: it is nongrowing in the absence of gravistimulation and capable of displaying a graviresponse independent of the rest of the plant. In this paper we present a model for gravitropism in pulvini based on recent findings from studies on the mechanisms of graviperception and graviresponse. According to this model, amyloplasts play an essential role in perceiving a change in the orientation of the pulvinus. The perception of this reorientation leads to the enhanced synthesis and release from conjugate of the auxin IAA, and the increased conjugation of gibberellin, on a localized basis. Because there is a graded growth promotion across the gravistimulated pulvinus, it is suggested that the observed hormonal asymmetry is actually an indication of a linear gradient of hormone concentration, as well as hormone response, across the pulvinus. It is further suggested that the linear gradient of hormone concentration may be predominantly the result of local changes in hormone level, rather than a product of hormonal movement into or across the pulvinus.

  16. Metabolite Profiles of Lactic Acid Bacteria in Grass Silage▿

    PubMed Central

    Broberg, Anders; Jacobsson, Karin; Ström, Katrin; Schnürer, Johan

    2007-01-01

    The metabolite production of lactic acid bacteria (LAB) on silage was investigated. The aim was to compare the production of antifungal metabolites in silage with the production in liquid cultures previously studied in our laboratory. The following metabolites were found to be present at elevated concentrations in silos inoculated with LAB strains: 3-hydroxydecanoic acid, 2-hydroxy-4-methylpentanoic acid, benzoic acid, catechol, hydrocinnamic acid, salicylic acid, 3-phenyllactic acid, 4-hydroxybenzoic acid, (trans, trans)-3,4-dihydroxycyclohexane-1-carboxylic acid, p-hydrocoumaric acid, vanillic acid, azelaic acid, hydroferulic acid, p-coumaric acid, hydrocaffeic acid, ferulic acid, and caffeic acid. Among these metabolites, the antifungal compounds 3-phenyllactic acid and 3-hydroxydecanoic acid were previously isolated in our laboratory from liquid cultures of the same LAB strains by bioassay-guided fractionation. It was concluded that other metabolites, e.g., p-hydrocoumaric acid, hydroferulic acid, and p-coumaric acid, were released from the grass by the added LAB strains. The antifungal activities of the identified metabolites in 100 mM lactic acid were investigated. The MICs against Pichia anomala, Penicillium roqueforti, and Aspergillus fumigatus were determined, and 3-hydroxydecanoic acid showed the lowest MIC (0.1 mg ml−1 for two of the three test organisms). PMID:17616609

  17. Cellulose nanofiber extraction from grass by a modified kitchen blender

    NASA Astrophysics Data System (ADS)

    Nakagaito, Antonio Norio; Ikenaga, Koh; Takagi, Hitoshi

    2015-03-01

    Cellulose nanofibers have been used to reinforce polymers, delivering composites with strength that in some cases can be superior to that of engineering plastics. The extraction of nanofibers from plant fibers can be achieved through specialized equipment that demands high energy input, despite delivering extremely low yields. The high extraction cost confines the use of cellulose nanofibers to the laboratory and not for industrial applications. This study aims to extract nanofibers from grass by using a kitchen blender. Earlier studies have demonstrated that paper sheets made of blender-extracted nanofibers (after 5 min to 10 min of blending) have strengths on par with paper sheets made from commercially available cellulose nanofibers. By optimizing the design of the blender bottle, nanofibrillation can be achieved in shorter treatment times, reducing the energy consumption (in the present case, to half) and the overall extraction cost. The raw materials used can be extended to the residue straw of agricultural crops, as an alternative to the usual pulp fibers obtained from wood.

  18. Water-soluble reaction products from ozonolysis of grasses

    SciTech Connect

    Morrison, W.H. III; Akin, D.E. )

    1990-03-01

    Ozone has been used to pretreat agricultural byproducts with the aim of increasing nutritive value for ruminants. However, not all treatments with ozone result in enhanced digestibility, suggesting reaction products from ozone treatment of plants might inhibit rumen microbial activity. Coastal Bermuda grass (Cynodon dactylon L. Pers.) (CBG) and Kentucky-31 tall fescue (Festuca arundinacea Schreb.) (K-31) were treated with ozone and the water-soluble products determined. The following acids were identified: caproic, levulinic, p-hydroxybenzoic, vinillic, azelaic, and malonic. In addition, vanillin and p-hydroxybenzaldehyde were also identified. Ozone treatment of the cell walls of CBG produced mainly p-hydroxybenzoic acid, vanillic acid, azelaic acid, p-hydroxybenzaldehyde, and vanillin. Ozone treatment of K-31 cell walls produced levulinic acid in addition to those products found from CBG cell walls. The production of vanillin and p-hydroxybenzaldehyde, which have been shown to be especially toxic to rumen microorganisms, offers an explanation for the negative affects of ozone treatment on forage.

  19. Assessing mesquite-grass vegetation condition from Landsat

    USGS Publications Warehouse

    McDaniel, Kirk C.; Haas, Robert H.

    1982-01-01

    Landsat multispectral scanner (MSS) band values, band ratios, and vegetation index models were compared with selected rangeland vegetation parameters collected at six test sites within the honey mesquitellotebushlmixed grass association in north-central Texas. The comparisons at four dates showed that two vegetation index models, TV16 and GVI, are highly correlated (P = 0.01) with green yield, green cover, and plant moisture content. The green vegetation index (GVZ) developed by Kauth and Thomas (1976), was highly correlated and superior to other models in relationship to wet green yield, dry green yield, and cured vegetation cover. TV16, developed by Rouse et al. (1974), was more highly correlated with green vegetation cover and vegetation moisture content. Both TV16 and GVI are superior to other models in their relationship with green cover. None of the Landsat MSS parameters tested was significantly correlated with dry total yield, percent bare ground, or moisture of the soil measured at the surface or at a 20 cm depth. I t is concluded that Landsat MSS data are sensitive to seasonal changes in vegetation growth conditions and inherent ecological differences within a relatively unqorm vegetationlsoil system.

  20. Grass plants bind, retain, uptake, and transport infectious prions.

    PubMed

    Pritzkow, Sandra; Morales, Rodrigo; Moda, Fabio; Khan, Uffaf; Telling, Glenn C; Hoover, Edward; Soto, Claudio

    2015-05-26

    Prions are the protein-based infectious agents responsible for prion diseases. Environmental prion contamination has been implicated in disease transmission. Here, we analyzed the binding and retention of infectious prion protein (PrP(Sc)) to plants. Small quantities of PrP(Sc) contained in diluted brain homogenate or in excretory materials (urine and feces) can bind to wheat grass roots and leaves. Wild-type hamsters were efficiently infected by ingestion of prion-contaminated plants. The prion-plant interaction occurs with prions from diverse origins, including chronic wasting disease. Furthermore, leaves contaminated by spraying with a prion-containing preparation retained PrP(Sc) for several weeks in the living plant. Finally, plants can uptake prions from contaminated soil and transport them to aerial parts of the plant (stem and leaves). These findings demonstrate that plants can efficiently bind infectious prions and act as carriers of infectivity, suggesting a possible role of environmental prion contamination in the horizontal transmission of the disease.

  1. Seed defensins of barnyard grass Echinochloa crusgalli (L.) Beauv.

    PubMed

    Odintsova, Tatyana I; Rogozhin, Eugene A; Baranov, Yurij; Musolyamov, Alexander Kh; Yalpani, Nasser; Egorov, Tsezi A; Grishin, Eugene V

    2008-01-01

    From the annual weed barnyard grass Echinochloa crusgalli (L.) Beauv., two novel defensins Ec-AMP-D1 and Ec-AMP-D2 that differ by a single amino acid substitution were isolated by a combination of different chromatographic procedures. Both defensins were active against several phytopathogenic fungi and the oomycete Phytophthora infestans at micromolar concentrations. The Ec-AMP-D1 showed higher activity against the oomycete than Ec-AMP-D2. The comparison of the amino acid sequences of the antifungal E. crusgalli defensins with those of earlier characterized T. kiharae defensins [T.I. Odintsova, Ts.A. Egorov, A.Kh. Musolyamov, M.S. Odintsova, V.A. Pukhalsky, E.V. Grishin, Seed defensins from T. kiharae and related species: genome localization of defensin-encoding genes, Biochimie, 89 (2007) 605-612.] that were devoid of substantial antifungal activity point to the C-terminal region of the molecule as the main determinant of the antifungal activity of E. crusgalli defensins.

  2. Duck nesting in fields of undisturbed grass-legume cover

    USGS Publications Warehouse

    Duebbert, H.F.; Lokemoen, J.T.

    1976-01-01

    A study of dabbling duck (Anatinae) nesting was conducted during 1971-73 on nine 12- to 54-ha Cropland Adjustment Program fields in the prairie pothole region of north-central South Dakota. The tall, dense vegetation was comprised of introduced cool-season grasses and legumes, primarily smooth bromegrass (Bromus inermis), intermediate wheatgrass (Agropyron intermedium), and alfalfa. Complexes of temporary, seasonal, and semipermanent wetlands surrounded the fields at densities of 1.5-8.1 basins/km2 and areas of 9.4-17.2 ha/km2. Of the 620 nests studied, 38 percent were of blue-winged teal (Anas discors), 24 percent were of mallards (A. platyrhynchos), and 24 percent were of gadwalls (A. strepera). Densities of nests of all species averaged 67, 114, and 47 nests/km2 (3-yr av 77/km2). Calculated hatching rates were 69, 58, and 32 percent (av 56) for the 3 years. Hatchability of eggs in successful nests averaged 97.1 percent. Averages of 4.0, 6.2, and 1.2 ducklings were hatched per hectare in 1971, 1972, and 1973, respectively (3-yr av 3.7/ha).

  3. Extreme genetic diversity in asexual grass thrips populations.

    PubMed

    Fontcuberta García-Cuenca, A; Dumas, Z; Schwander, T

    2016-05-01

    The continuous generation of genetic variation has been proposed as one of the main factors explaining the maintenance of sexual reproduction in nature. However, populations of asexual individuals may attain high levels of genetic diversity through within-lineage diversification, replicate transitions to asexuality from sexual ancestors and migration. How these mechanisms affect genetic variation in populations of closely related sexual and asexual taxa can therefore provide insights into the role of genetic diversity for the maintenance of sexual reproduction. Here, we evaluate patterns of intra- and interpopulation genetic diversity in sexual and asexual populations of Aptinothrips rufus grass thrips. Asexual A. rufus populations are found throughout the world, whereas sexual populations appear to be confined to few locations in the Mediterranean region. We found that asexual A. rufus populations are characterized by extremely high levels of genetic diversity, both in comparison with their sexual relatives and in comparison with other asexual species. Migration is extensive among asexual populations over large geographic distances, whereas close sexual populations are strongly isolated from each other. The combination of extensive migration with replicate evolution of asexual lineages, and a past demographic expansion in at least one of them, generated high local clone diversities in A. rufus. These high clone diversities in asexual populations may mimic certain benefits conferred by sex via genetic diversity and could help explain the extreme success of asexual A. rufus populations.

  4. Hydraulic lift as a determinant of tree-grass coexistence on savannas.

    PubMed

    Yu, Kailiang; D'Odorico, Paolo

    2015-09-01

    The coexistence of woody plants and grasses in savannas is determined by a complex set of interacting factors that determine access to resources and demographic dynamics, under the control of external drivers and vegetation feedbacks with the physical environment. Existing theories explain coexistence mainly as an effect of competitive relations and/or disturbances. However, theoretical studies on the way facilitative interactions resulting from hydraulic lift affect tree-grass coexistence and the range of environmental conditions in which savannas are stable are still lacking. We investigated the role of hydraulic lift in the stability of tree-grass coexistence in savannas. To that end, we developed a new mechanistic model that accounts for both competition for soil water in the shallow soil and fire-induced disturbance. We found that hydraulic lift favors grasses, which scavenge the water lifted by woody plants. Thus, hydraulic lift expands (at the expenses of woodlands) the range of environmental conditions in which savannas are stable. These results indicate that hydraulic lift can be an important mechanism responsible for the coexistence of woody plants and grasses in savannas. Grass facilitation by trees through the process of hydraulic lift could allow savannas to persist stably in mesic regions that would otherwise exhibit a forest cover. PMID:25925655

  5. Climate, CO2, and the history of North American grasses since the Last Glacial Maximum.

    PubMed

    Cotton, Jennifer M; Cerling, Thure E; Hoppe, Kathryn A; Mosier, Thomas M; Still, Christopher J

    2016-03-01

    The spread of C4 grasses in the late Neogene is one of the most important ecological transitions of the Cenozoic, but the primary driver of this global expansion is widely debated. We use the stable carbon isotopic composition (δ(13)C) of bison and mammoth tissues as a proxy for the relative abundance of C3 and C4 vegetation in their grazing habitat to determine climatic and atmospheric CO2 controls on C4 grass distributions from the Last Glacial Maximum (LGM) to the present. We predict the spatial variability of grass δ(13)C in North America using a mean of three different methods of classification and regression tree (CART) machine learning techniques and nine climatic variables. We show that growing season precipitation and temperature are the strongest predictors of all single climate variables. We apply this CART analysis to high-resolution gridded climate data and Coupled Model Intercomparison Project (CMIP5) mean paleoclimate model outputs to produce predictive isotope landscape models ("isoscapes") for the current, mid-Holocene, and LGM average δ(13)C of grass-dominated areas across North America. From the LGM to the present, C4 grass abundances substantially increased in the Great Plains despite concurrent increases in atmospheric CO2. These results suggest that changes in growing season precipitation rather than atmospheric CO2 were critically important in the Neogene expansion of C4 grasses. PMID:27051865

  6. Climate, CO2, and the history of North American grasses since the Last Glacial Maximum

    PubMed Central

    Cotton, Jennifer M.; Cerling, Thure E.; Hoppe, Kathryn A.; Mosier, Thomas M.; Still, Christopher J.

    2016-01-01

    The spread of C4 grasses in the late Neogene is one of the most important ecological transitions of the Cenozoic, but the primary driver of this global expansion is widely debated. We use the stable carbon isotopic composition (δ13C) of bison and mammoth tissues as a proxy for the relative abundance of C3 and C4 vegetation in their grazing habitat to determine climatic and atmospheric CO2 controls on C4 grass distributions from the Last Glacial Maximum (LGM) to the present. We predict the spatial variability of grass δ13C in North America using a mean of three different methods of classification and regression tree (CART) machine learning techniques and nine climatic variables. We show that growing season precipitation and temperature are the strongest predictors of all single climate variables. We apply this CART analysis to high-resolution gridded climate data and Coupled Model Intercomparison Project (CMIP5) mean paleoclimate model outputs to produce predictive isotope landscape models (“isoscapes”) for the current, mid-Holocene, and LGM average δ13C of grass-dominated areas across North America. From the LGM to the present, C4 grass abundances substantially increased in the Great Plains despite concurrent increases in atmospheric CO2. These results suggest that changes in growing season precipitation rather than atmospheric CO2 were critically important in the Neogene expansion of C4 grasses. PMID:27051865

  7. Spatial distributions of grass shrimp (Palaemonetes pugio) populations in southeastern estuarine ecosystems influenced by urbanization

    SciTech Connect

    Scott, G.; Daugomah, J.; Devane, J.; Porter, D.; Edwards, D.

    1995-12-31

    Urbanization of coastal regions has resulted in the increased discharge of polycyclic aromatic hydrocarbons trace metals and habitat changes/modifications in adjacent upland areas which may affect grass shrimp populations. A study was conducted comparing larval abundance and adult grass shrimp biomass, abundance, size structure and sex ratios in an urbanized estuary, Murrells Inlet with pristine North Inlet, a NOAA national estuarine research reserve and sanctuary site. A total of 60 sites were sampled during the peak of grass shrimp abundance and compared in terms of spatial distributions and other relevant ancillary information. Factors such as sediment contaminant levels, physico-chemical parameters and land-use habitat modification were statistically compared using a Geographical Information Processing (GIP) techniques and appropriate spatial statistical methods. GIP results indicated similar levels of larval abundance in both estuaries and identified specific nursery ground regions in both estuaries. Adult grass shrimp abundances were greatly reduced in urban areas and grass shrimp desert regions were identified. These areas were correlated with regions having high levels of chemical contaminants and greatest physical disturbances. The mortality rate between larval and adult stages was much higher in urban areas suggesting that urbanization had a profound impact on grass shrimp.

  8. The perennial ryegrass GenomeZipper: targeted use of genome resources for comparative grass genomics.

    PubMed

    Pfeifer, Matthias; Martis, Mihaela; Asp, Torben; Mayer, Klaus F X; Lübberstedt, Thomas; Byrne, Stephen; Frei, Ursula; Studer, Bruno

    2013-02-01

    Whole-genome sequences established for model and major crop species constitute a key resource for advanced genomic research. For outbreeding forage and turf grass species like ryegrasses (Lolium spp.), such resources have yet to be developed. Here, we present a model of the perennial ryegrass (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to establish the chromosomal arrangement of syntenic genes from model grass species. This scaffold revealed a high degree of synteny and macrocollinearity and was then utilized to anchor a collection of perennial ryegrass genes in silico to their predicted genome positions. This resulted in the unambiguous assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The perennial ryegrass GenomeZipper is an ordered, information-rich genome scaffold, facilitating map-based cloning and genome assembly in perennial ryegrass and closely related Poaceae species. It also represents a milestone in describing synteny between perennial ryegrass and fully sequenced model grass genomes, thereby increasing our understanding of genome organization and evolution in the most important temperate forage and turf grass species.

  9. Establishment and growth of experimental grass species mixtures on coal mine sites reclaimed with municipal biosolids

    SciTech Connect

    Halofsky, J.E.; McCormick, L.H.

    2005-05-01

    The Surface Mining Control and Reclamation Act of 1977 requires that coal mine sites in the United States be reclaimed to establish vegetative cover that is diverse, native, and capable of plant succession. However, there is a question as to whether vegetation established on coal mine sites reclaimed with biosolids is diverse and capable of plant succession. The influx of nutrients with the addition of biosolids leads to long-term dominance by early-successional species, most notably grasses, and consequently, a low establishment of woody and volunteer species. Additionally, many grass species commonly planted in reclamation have aggressive growth habits that lead to their dominance in coal mine plant communities. The establishment and growth of selected grass mixes was evaluated to determine whether alternative grass mixes would be less competitive with woody and volunteer species as compared to commonly used grass mixes. Percent vegetative cover, species richness, and the survival of direct-seeded woody species were assessed for each treatment grass mixture. It was found that Poa compress and a mixture of P. compress, Panicum virgatum, and Trifolium repens provided adequate coverage while still allowing the highest species richness and survival of woody species. Use of these species mixtures in coal mine reclamation with biosolids in the eastern United States would likely lead to establishment of a more species-rich plant community with a greater woody species component while still providing erosion control and site protection.

  10. Reclamation of abandoned shrimp pond soils in southern Thailand for cultivation of Mauritius grass (Brachiaria mutica).

    PubMed

    Towatana, P; Voradej, C; Leeraphante, N

    2003-09-01

    A study on soil reclamation for cultivation of Mauritius grass was conducted on soils obtained from abandoned shrimp ponds at Ranote District, Songkhla Province, southern Thailand. A glass house experiment on the reclamation of the soils included desalination by leaching soils using various amounts of deionised water, rice husk, plant nutrients and gypsum as well as an omission pot trial experiment. The result showed that Mauritius grass survived in the treatment with > or = 15 L of water, > or = 2% of rice husk with gypsum added or > or = 8% of rice husk without gypsum added. The yield of Mauritius grass increased with increases in the amounts of water for desalination and rice husk. Thus, the highest yield of grass with a height of 148.3 cm, 12.7 tillers/pot and dry weight of 46.43 g/pot was observed in the gypsum added treatment with the highest amount of water and rice husk (25 L of water and 8% by weight of rice husk). Therefore, salinity and unfavourable structure of the abandoned pond soils were major factors governing the survival ability and growth of the grass. The omission pot trial experiment revealed that growth of the grass responded to the application of P, Ca, Mg and S, though existing amounts of such plant nutrient elements in the soils were adequate for plant growth. The anomalous characteristics were probably explained by soil pH, salinity and imbalance of plant nutrient elements.

  11. Hydraulic lift as a determinant of tree-grass coexistence on savannas.

    PubMed

    Yu, Kailiang; D'Odorico, Paolo

    2015-09-01

    The coexistence of woody plants and grasses in savannas is determined by a complex set of interacting factors that determine access to resources and demographic dynamics, under the control of external drivers and vegetation feedbacks with the physical environment. Existing theories explain coexistence mainly as an effect of competitive relations and/or disturbances. However, theoretical studies on the way facilitative interactions resulting from hydraulic lift affect tree-grass coexistence and the range of environmental conditions in which savannas are stable are still lacking. We investigated the role of hydraulic lift in the stability of tree-grass coexistence in savannas. To that end, we developed a new mechanistic model that accounts for both competition for soil water in the shallow soil and fire-induced disturbance. We found that hydraulic lift favors grasses, which scavenge the water lifted by woody plants. Thus, hydraulic lift expands (at the expenses of woodlands) the range of environmental conditions in which savannas are stable. These results indicate that hydraulic lift can be an important mechanism responsible for the coexistence of woody plants and grasses in savannas. Grass facilitation by trees through the process of hydraulic lift could allow savannas to persist stably in mesic regions that would otherwise exhibit a forest cover.

  12. Establishment and growth of experimental grass species mixtures on coal mine sites reclaimed with municipal biosolids.

    PubMed

    Halofsky, Jessica E; McCormick, Larry H

    2005-05-01

    The Surface Mining Control and Reclamation Act of 1977 requires that coal mine sites in the United States be reclaimed to establish vegetative cover that is diverse, native, and capable of plant succession. However, there is a question as to whether vegetation established on coal mine sites reclaimed with biosolids is diverse and capable of plant succession. The influx of nutrients with the addition of biosolids leads to long-term dominance by early-successional species, most notably grasses, and consequently, a low establishment of woody and volunteer species. Additionally, many grass species commonly planted in reclamation have aggressive growth habits that lead to their dominance in coal mine plant communities. The establishment and growth of selected grass mixes was evaluated to determine whether alternative grass mixes would be less competitive with woody and volunteer species as compared to commonly used grass mixes. Percent vegetative cover, species richness, and the survival of direct-seeded woody species were assessed for each treatment grass mixture. It was found that Poa compressa and a mixture of P. compressa, Panicum virgatum, and Trifolium repens provided adequate coverage while still allowing the highest species richness and survival of woody species. Use of these species mixtures in coal mine reclamation with biosolids in the eastern United States would likely lead to establishment of a more species-rich plant community with a greater woody species component while still providing erosion control and site protection. PMID:15920668

  13. Does a tradeoff exist between morphological and physiological root plasticity? A comparison of grass growth forms

    NASA Astrophysics Data System (ADS)

    Derner, Justin D.; Briske, David D.

    1999-09-01

    A series of experiments were conducted to evaluate the potential tradeoff between morphological and physiological root plasticity in caespitose and rhizomatous grass growth forms in semi-arid and mesic communities. Morphological and physiological root plasticity were evaluated with in-growth cores and excised root assays, respectively. The rhizomatous grass in the semi-arid community was the only species to display significant physiological root plasticity, but all species possessed the capacity to proportionally increase 15N uptake with increasing concentrations of ( 15NH 4) 2SO 4 solution. Neither the caespitose nor the rhizomatous grass displayed morphological root plasticity in response to nitrogen addition in the mesic community. In contrast, significant morphological root plasticity occurred in species of both growth forms in the semi-arid community. These data suggest that the compact architecture and the ability to accumulate nutrients in soils directly beneath caespitose grasses did not increase selection pressure for physiological root plasticity at the expense of morphological root plasticity and that the coarse grained foraging strategy and low density of large diameter roots did not increase morphological root plasticity at the expense of physiological root plasticity in rhizomatous grasses. These preliminary data suggest that 1) a high maximum uptake rate for nitrogen in these perennial grasses may minimize the expression of physiological root plasticity, 2) morphological and physiological root plasticity may represent complimentary, rather than alternative, foraging strategies, and 3) the expression of root plasticity may be strongly influenced by abiotic variables within specific habitats.

  14. Seasonal infestations of two stem borers (Lepidoptera: Crambidae) in noncrop grasses of Gulf Coast rice agroecosystems.

    PubMed

    Beuzelin, J M; Mészáros, A; Reagan, T E; Wilson, L T; Way, M O; Blouin, D C; Showler, A T

    2011-10-01

    Infestations of two stem borers, Eoreuma loftini (Dyar) and Diatraea saccharalis (F.) (Lepidoptera: Crambidae), were compared in noncrop grasses adjacent to rice (Oryza sativa L.) fields. Three farms in the Texas rice Gulf Coast production area were surveyed every 6-8 wk between 2007 and 2009 using quadrat sampling along transects. Although D. saccharalis densities were relatively low, E. loftini average densities ranged from 0.3 to 5.7 immatures per m(2) throughout the 2-yr period. Early annual grasses including ryegrass, Lolium spp., and brome, Bromus spp., were infested during the spring, whereas the perennial johnsongrass, Sorghum halepense (L.) Pers., and Vasey's grass, Paspalum urvillei Steud., were infested throughout the year. Johnsongrass was the most prevalent host (41-78% relative abundance), but Vasey's grass (13-40% relative abundance) harbored as much as 62% of the recovered E. loftini immatures (during the winter). Young rice in newly planted fields did not host stem borers before June. April sampling in fallow rice fields showed that any available live grass material, volunteer rice or weed, can serve as a host during the spring. Our study suggests that noncrop grasses are year-round sources of E. loftini in Texas rice agroecosystems and may increase pest populations.

  15. Response of itchgrass and johnson grass to asulam/dalapon combinations

    SciTech Connect

    Hook, B.J.

    1986-01-01

    Activities of asumlam (methyl((4-aminophenyl)sulfonyl)carbamate), dalapon (2,2-dichloropropionic acid) and asulam/dalapon combinations on itchgrass (Rottboellia exaltata L.f.) and johnson grass (Sorghum halepense (L.) Pers.) were examined. When metabolism of /sup 14/C-asulam was monitored, seven days after application, 97-100% of recovered /sup 14/C co-chromatographed with /sup 14/C-asulam. Itchgrass exhibited rapid uptake of /sup 14/C-asulam within 8 hr after application. Asumlam concentrations remained constant in the plant between 8 and 72 hr. Johnson grass plants showed a differential response to asulam and asulam/dalapon treatments. Asulam-treated johnson grass absorbed 26-34% /sup 14/C within 2 hr with no future significant increase in absorption in absorption through 72 hr. Treatment of johnson grass with asulam/dalapon enhanced /sup 14/C absorption with time. At 24 and 72 hr /sup 14/C levels were double that absorbed from treatment of asulam alone. Movement of /sup 14/C-asulam in the apoplast and symplast of both itchgrass and johnson grass was noted. The highest radiolabel accumulated in the lower leaves of itchgrass and remained in the treated leaf of johnson grass.

  16. Effect of Two Oil Dispersants on Larval Grass Shrimp (Palaemonetes pugio) Development.

    NASA Astrophysics Data System (ADS)

    Betancourt, P.; Key, P. B.; Chung, K. W.; DeLorenzo, M. E.

    2015-12-01

    The study focused on the effects that two oil dispersants, Corexit® EC9500A and Finasol® OSR52, have on the development of larval grass shrimp, (Palaemonetes pugio). The hypothesis was that Finasol would have a greater effect on larval grass shrimp development than Corexit. The experiment was conducted using 300 grass shrimp larvae that were 24 hours old. Each larva was exposed individually. In total, five sub-lethal concentrations were tested for each dispersant (control, 1.25, 2.50, 5.0,10.0 mg/L). The larvae were exposed for five days then transferred to clean seawater until metamorphosis into the juvenile stage. Key data measurements recorded included number of days to become juveniles, number of instars, length, dry weight, and mortality. Data from exposed shrimp was compared to the results of the control for each dispersant concentration. Corexit and Finasol exposure treatments of 5 mg/L and 10 mg/L showed significantly higher values for number of days and number of instars to reach juvenile status than values obtained from unexposed, control shrimp. Overall, mortality was higher in the Finasol treatments but the two dispersants did not respond significantly different from one another. Future studies are needed to determine the long term effects of dispersant exposure on all grass shrimp life stages and how any dispersant exposure impacts grass shrimp populations. Grass shrimp serve as excellent toxicity indicators of estuaries, and further studies will help to develop better oil spill mitigation techniques.

  17. Monoclonal antibodies to the major Lolium perenne (rye grass) pollen allergen Lol p I (Rye I).

    PubMed

    Kahn, C R; Marsh, D G

    1986-12-01

    Thirteen monoclonal antibodies (MAbs) were produced against Lol p I (Rye I), the major Lolium perenne (rye grass) pollen allergen. Spleen cells from A/J and SJL mice immunized with highly purified Lol p I (Lol I) were allowed to fuse with cells from the non-secreting Sp2/0-Ag14 myeloma cell line. Each MAb was analyzed for antigenic specificity by radioimmunoassay (RIA) using 125I-Lol I. The epitope specificities of seven of the MAbs were examined by competitive binding against a labelled standard MAb for the Lol I antigen (Ag). The dissociation constant, Kd, of one MAb (No. 3.2) that was studied most extensively was determined by double Ab RIA to be 3.5 X 10(-6) L/M. This MAb recognized the related 27,000-30,000 Group I glycoproteins found in the pollens of nine other species of grass pollens tested, including weak binding to Bermuda grass Group I (Cyn d I), which by conventional analysis using polyclonal anti-Lol I serum shows no detectable binding. Monoclonal antibody No. 3.2 was coupled covalently to Sepharose 4B and used to prepare highly purified Lol I from a partially purified rye pollen extract. Finally, an RIA was developed which permitted the analysis of the Group I components in rye grass and nine other grass pollen species. The latter assay is likely to prove useful in the standardization of grass pollen extracts according to their Group I contents.

  18. Photosynthesis of C3, C3-C4, and C4 grasses at glacial CO2.

    PubMed

    Pinto, Harshini; Sharwood, Robert E; Tissue, David T; Ghannoum, Oula

    2014-07-01

    Most physiology comparisons of C3 and C4 plants are made under current or elevated concentrations of atmospheric CO2 which do not reflect the low CO2 environment under which C4 photosynthesis has evolved. Accordingly, photosynthetic nitrogen (PNUE) and water (PWUE) use efficiency, and the activity of the photosynthetic carboxylases [Rubisco and phosphoenolpyruvate carboxylase (PEPC)] and decarboxylases [NADP-malic enzyme (NADP-ME) and phosphoenolpyruvate carboxykinase (PEP-CK)] were compared in eight C4 grasses with NAD-ME, PCK, and NADP-ME subtypes, one C3 grass, and one C3-C4 grass grown under ambient (400 μl l(-1)) and glacial (180 μl l(-1)) CO2. Glacial CO2 caused a smaller reduction of photosynthesis and a greater increase of stomatal conductance in C4 relative to C3 and C3-C4 species. Panicum bisulcatum (C3) acclimated to glacial [CO2] by doubling Rubisco activity, while Rubisco was unchanged in Panicum milioides (C3-C4), possibly due to its high leaf N and Rubisco contents. Glacial CO2 up-regulated Rubisco and PEPC activities in concert for several C4 grasses, while NADP-ME and PEP-CK activities were unchanged, reflecting the high control exerted by the carboxylases relative to the decarboxylases on the efficiency of C4 metabolism. Despite having larger stomatal conductance at glacial CO2, C4 species maintained greater PWUE and PNUE relative to C3-C4 and C3 species due to higher photosynthetic rates. Relative to other C4 subtypes, NAD-ME and PEP-CK grasses had the highest PWUE and PNUE, respectively; relative to C3, the C3-C4 grass had higher PWUE and similar PNUE at glacial CO2. Biomass accumulation was reduced by glacial CO2 in the C3 grass relative to the C3-C4 grass, while biomass was less reduced in NAD-ME grasses compared with NADP-ME and PCK grasses. Under glacial CO2, high resource use efficiency offers a key evolutionary advantage for the transition from C3 to C4 photosynthesis in water- and nutrient-limited environments.

  19. Late Quaternary vegetation changes around Lake Rutundu, Mount Kenya, East Africa: evidence from grass cuticles, pollen and stable carbon isotopes

    NASA Astrophysics Data System (ADS)

    Wooller, M. J.; Swain, D. L.; Ficken, K. J.; Agnew, A. D. Q.; Street-Perrott, F. A.; Eglinton, G.

    2003-01-01

    Woody, subalpine shrubs and grasses currently surround Lake Rutundu, Mount Kenya. Multiple proxies, including carbon isotopes, pollen and grass cuticles, from a 755-cm-long core were used to reconstruct the vegetation over the past 38 300 calendar years. Stable carbon-isotope ratios of total organic carbon and terrestrial biomarkers from the lake sediments imply that the proportion of terrestrial plants using the C4 photosynthetic pathway was greater during the Late Pleistocene than in the Holocene. Pollen data show that grasses were a major constituent of the vegetation throughout the Late Pleistocene and Holocene. The proportion of grass pollen relative to the pollen from other plants was greatest at the last glacial maximum (LGM). Grass cuticles confirm evidence that C4 grass taxa were present at the LGM and that the majority followed the cold-tolerant NADP-MEC4 subpathway.

  20. Evaluating indigenous grass species as on-site sediment trapping measures, northwest Ethiopian highlands

    NASA Astrophysics Data System (ADS)

    Mekonnen, Mulatie; Keesstra, Saskia; Ritsema, Coen; Stroosnijder, Leo; Baartman, Jantiene

    2016-04-01

    Although many studies have been conducted to evaluate the sediment trapping efficacy (STE) of grass species as an on-site sediment trapping measure, still a lot of grass species are availab1e of which their STE is unknown. Lack of information on the STE of such grass species has a negative influence on their acceptance and practical application by the users. Therefore, this study was conducted at Debre Mewi watershed, northwestern Ethiopian highlands, to evaluate the STE of four locally dominant indigenous grass species (Desho, Senbelet, Akirma and Sebez) and one exotic species (Vetiver) using plot experiments. On average, the annual runoff produced was found to be 79; 64; 69; 71; 74; 75 l m-2, which resulted in 7; 1.7; 2.9; 3.6; 4.5 and 5.6 kg m-2 yr-1 of sediment yield on the Control, Desho, Vetiver, Senbelet, Akirma and Sebez plots, respectively. Desho had a trapping efficacy of 76 % because of its fast growth and lateral spreading nature. Vetiver and Senbelet reduced the transported sediment with 59 % and 49 % STE, respectively. Because of their slow growth nature, Akirma and Sebez showed low STEs, 36 % and 20 %, respectively. The grass species were found to be important sources of livestock feed in addition to trapping sediment and reducing soil loss. Desho, Senbelet, Akirma, Vetiver and Sebez provided 132, 106, 76, 69 and 51 t ha-1 yr-1 fresh biomass, respectively. The indigenous grass species provided a practical means to reduce sediment yield, therefore, it can be concluded that such indigenous grass species can be used as an on-site sediment trapping measure in the northwestern highlands of Ethiopia.

  1. Mineral concentration in selected native temperate grasses with potential use as biofuel feedstock.

    PubMed

    El-Nashaar, H M; Griffith, S M; Steiner, J J; Banowetz, G M

    2009-07-01

    Stands of native grasses along roadways, in buffer strips, riparian zones and grass prairies have potential utility as feedstock for bioenergy production. The sustainability of harvesting these stands is reliant, in part, on knowledge of the mineral concentration of the harvested grasses because removal of mineral nutrients such as phosphorus (P) and potassium (K) can impact subsequent biomass production and ecosystem services associated with these stands. Mineral content of biomass, particularly that of silicon (Si), chlorine (Cl), and sulfur (S) also impacts thermochemical conversion approaches that convert grasses into bioproducts. This study quantified Cl, S, Si, P and K in Bromus marginatus, Elymus glaucus, Poa secunda, Pseudoroegneria, Elymus lanceolatus, Elymus trachycaulus, Leymus cinereus, Leymus triticoides, and Pseudoroegneria spicata collected at three growth developmental stages from four plant introduction stations located in the western US. Differences (P< or =0.05) in mineral concentrations were associated with developmental stage, species, and location. Variability was greatest in Si concentrations which ranged from 1847 to 28620 mg kg(-1), similar to those recorded in other grasses. Variability in Cl and S concentrations also occurred, but at less magnitude than that of Si. Concentrations of P and K, two mineral fertilizer components, varied approximately threefold among these grasses. Differences in mineral concentrations among these grasses were not completely dependent upon soil mineral content. Long-term evaluations of available soil mineral concentrations under contrasting management practices are needed to quantify how local conditions impact mineral cycling, and in turn, the sustainability of harvesting these stands. The data presented here establish baselines for these species in locations subject to contrasting environmental and microbiological conditions that affect mineral cycling and availability.

  2. Satellite Phenology Observations Inform Peak Season of Allergenic Grass Pollen Aerobiology across Two Continents

    NASA Astrophysics Data System (ADS)

    Huete, A. R.; Devadas, R.; Davies, J.

    2015-12-01

    Pollen exposure and prevalence of allergenic diseases have increased in many parts of the world during the last 30 years, with exposure to aeroallergen grass pollen expected to intensify with climate change, raising increased concerns for allergic diseases. The primary contributing factors to higher allergenic plant species presence are thought to be climate change, land conversion, and biotic mixing of species. Conventional methods for monitoring airborne pollen are hampered by a lack of sampling sites and heavily rely on meteorology with less attention to land cover updates and monitoring of key allergenic species phenology stages. Satellite remote sensing offers an alternative method to overcome the restrictive coverage afforded by in situ pollen networks by virtue of its synoptic coverage and repeatability of measurements that enable timely updates of land cover and land use information and monitoring landscape dynamics and interactions with human activity and climate. In this study, we assessed the potential of satellite observations of urban/peri-urban environments to directly inform landscape conditions conducive to pollen emissions. We found satellite measurements of grass cover phenological evolution to be highly correlated with in situ aerobiological grass pollen concentrations in five urban centres located across two hemispheres (Australia and France). Satellite greenness data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were found to be strongly synchronous with grass pollen aerobiology in both temperate grass dominated sites (France and Melbourne), as well as in Sydney, where multiple pollen peaks coincided with the presence of subtropical grasses. Employing general additive models (GAM), the satellite phenology data provided strong predictive capabilities to inform airborne pollen levels and forecast periods of grass pollen emissions at all five sites. Satellite phenology offer promising opportunities of improving public health risk

  3. Long-term impacts of invasive grasses and subsequent fire in seasonally dry Hawaiian woodlands.

    PubMed

    D'Antonio, Carla M; Hughes, R F; Tunison, J T

    2011-07-01

    Invasive nonnative grasses have altered the composition of seasonally dry shrublands and woodlands throughout the world. In many areas they coexist with native woody species until fire occurs, after which they become dominant. Yet it is not clear how long their impacts persist in the absence of further fire. We evaluated the long-term impacts of grass invasions and subsequent fire in seasonally dry submontane habitats on Hawai'i, USA. We recensused transects in invaded unburned woodland and woodland that had burned in exotic grass-fueled fires in 1970 and 1987 and had last been censused in 1991. In the unburned woodlands, we found that the dominant understory grass invader, Schizachyrium condensatum, had declined by 40%, while native understory species were abundant and largely unchanged from measurements 17 years ago. In burned woodland, exotic grass cover also declined, but overall values remained high and recruitment of native species was poor. Sites that had converted to exotic grassland after a 1970 fire remained dominated by exotic grasses with no increase in native cover despite 37 years without fire. Grass-dominated sites that had burned twice also showed limited recovery despite 20 years of fire suppression. We found limited evidence for "invasional meltdown": Exotic richness remained low across burned sites, and the dominant species in 1991, Melinis minutiflora, is still dominant today. Twice-burned sites are, however, being invaded by the nitrogen-fixing tree Morella faya, an introduced species with the potential to greatly alter the successional trajectory on young volcanic soils. In summary, despite decades of fire suppression, native species show little recovery in burned Hawaiian woodlands. Thus, burned sites appear to be beyond a threshold for "natural recovery" (e.g., passive restoration). PMID:21830706

  4. Mineral concentration in selected native temperate grasses with potential use as biofuel feedstock.

    PubMed

    El-Nashaar, H M; Griffith, S M; Steiner, J J; Banowetz, G M

    2009-07-01

    Stands of native grasses along roadways, in buffer strips, riparian zones and grass prairies have potential utility as feedstock for bioenergy production. The sustainability of harvesting these stands is reliant, in part, on knowledge of the mineral concentration of the harvested grasses because removal of mineral nutrients such as phosphorus (P) and potassium (K) can impact subsequent biomass production and ecosystem services associated with these stands. Mineral content of biomass, particularly that of silicon (Si), chlorine (Cl), and sulfur (S) also impacts thermochemical conversion approaches that convert grasses into bioproducts. This study quantified Cl, S, Si, P and K in Bromus marginatus, Elymus glaucus, Poa secunda, Pseudoroegneria, Elymus lanceolatus, Elymus trachycaulus, Leymus cinereus, Leymus triticoides, and Pseudoroegneria spicata collected at three growth developmental stages from four plant introduction stations located in the western US. Differences (P< or =0.05) in mineral concentrations were associated with developmental stage, species, and location. Variability was greatest in Si concentrations which ranged from 1847 to 28620 mg kg(-1), similar to those recorded in other grasses. Variability in Cl and S concentrations also occurred, but at less magnitude than that of Si. Concentrations of P and K, two mineral fertilizer components, varied approximately threefold among these grasses. Differences in mineral concentrations among these grasses were not completely dependent upon soil mineral content. Long-term evaluations of available soil mineral concentrations under contrasting management practices are needed to quantify how local conditions impact mineral cycling, and in turn, the sustainability of harvesting these stands. The data presented here establish baselines for these species in locations subject to contrasting environmental and microbiological conditions that affect mineral cycling and availability. PMID:19329307

  5. Early grass seedling growth stage improves explanation of future stand success

    SciTech Connect

    Ries, R.E.

    1999-07-01

    Predicting future grass stand success shortly after seeding improves the author's understanding of the mechanism of seeding success and makes possible timely decisions on the potential productivity of new grass stands. A 3-year field study with 5 species and 11 seeding dates per year was conducted to evaluate grass development and success when grass was direct seeded into wheat stubble with a double disk come seeder with depth bands and packer wheels. The number of grass seedlings/m{sup 2}, the number of adventitious roots, Haun stage, leaf length, leaf area, and number of tillers were measured 45 days after emergence. Earlier results showed that grass stand success can be reasonably predicted from the relationship of seedlings/m{sup 2} at 45 days after emergence with grass stems or plants/m{sup 2} 2 years after seeding. However, the simple coefficient of determination (r{sup 2}) for these relationships was quite low. further multiple regression analysis has shown that the R{sup 2} values can be significantly improved by adding the appropriate seedling growth stage to the number of seedlings/m{sup 2} at 45 days. For smooth bromegrass, the r{sup 2} was improved to 0.75 with the addition of adventitious roots, leaf area, and leaf length. The R{sup 2} was increased to 0.58 for crested wheatgrass and improved to 0.38 for western wheatgrass with the addition of number of adventitious roots. The R{sup 2} for blue grama was increased to 0.65 with the addition of number of adventitious roots. These data show that the explanation of the number of stems or plants/m{sup 2} estimated 2 years into the future is improved by knowing something about the developmental stage of the seedlings/m{sup 2} at 45 days after emergence.

  6. Modelling Water Uptake Provides a New Perspective on Grass and Tree Coexistence.

    PubMed

    Mazzacavallo, Michael G; Kulmatiski, Andrew

    2015-01-01

    Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize a water movement model (Hydrus 1D). The model accounted for water availability and estimated grass and tree water uptake by depth over a growing season. Most root biomass was found in shallow soils (0-20 cm) and tracer data revealed that, within these shallow depths, half of active grass roots were in the top 12 cm while half of active tree roots were in the top 21 cm. However, because shallow soils provided roots with less water than deep soils (20-90 cm), the water movement model indicated that grass and tree water uptake was twice as deep as would be predicted from root biomass or tracer data alone: half of grass and tree water uptake occurred in the top 23 and 43 cm, respectively. Niche partitioning was also greater when estimated from water uptake rather than tracer uptake. Contrary to long-standing assumptions, shallow grass root distributions absorbed 32% less water than slightly deeper tree root distributions when grasses and trees were assumed to have equal water demands. Quantifying water uptake revealed deeper soil water uptake, greater niche partitioning and greater benefits of deep roots than would be estimated from root biomass or tracer uptake data alone.

  7. Overland flow resistances on varying slope gradients and partitioning on grassed slopes under simulated rainfall

    NASA Astrophysics Data System (ADS)

    Pan, Chengzhong; Ma, Lan; Wainwright, John; Shangguan, Zhouping

    2016-04-01

    It is still unclear how slope steepness (S) and revegetation affect resistance (f) to overland flow. A series of experiments on runoff hydraulics was conducted on granular surfaces (bare soil and sandpaper) and grassed surfaces, including grass plots (GP), GP with litter (GL), and GP without leaves (GS) under simulated rainfall and inflow (30grass plots. A greater f occurred at the gentle and steep slopes for the granular surfaces, while f decreased with increasing slopes for the grass treatments. The different f-S relations suggest that f is not a simple function of S. When Re≈1000, the sowing rye grass with level lines increased f by approximately 100 times and decreased bed shear stress to approximately 5%. The contribution of grass leaves, stems, litter, and grain surface to total resistance in the grass plots were averagely 52%, 32%, 16%, and 1%. The greater resistance from leaves may result from the leaves lying at the plot surface impacted by raindrop impact. These results are beneficial to understand the dynamics of runoff and erosion on hillslopes impacted by vegetation restoration.

  8. Modelling Water Uptake Provides a New Perspective on Grass and Tree Coexistence.

    PubMed

    Mazzacavallo, Michael G; Kulmatiski, Andrew

    2015-01-01

    Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize a water movement model (Hydrus 1D). The model accounted for water availability and estimated grass and tree water uptake by depth over a growing season. Most root biomass was found in shallow soils (0-20 cm) and tracer data revealed that, within these shallow depths, half of active grass roots were in the top 12 cm while half of active tree roots were in the top 21 cm. However, because shallow soils provided roots with less water than deep soils (20-90 cm), the water movement model indicated that grass and tree water uptake was twice as deep as would be predicted from root biomass or tracer data alone: half of grass and tree water uptake occurred in the top 23 and 43 cm, respectively. Niche partitioning was also greater when estimated from water uptake rather than tracer uptake. Contrary to long-standing assumptions, shallow grass root distributions absorbed 32% less water than slightly deeper tree root distributions when grasses and trees were assumed to have equal water demands. Quantifying water uptake revealed deeper soil water uptake, greater niche partitioning and greater benefits of deep roots than would be estimated from root biomass or tracer uptake data alone. PMID:26633177

  9. Review of the integrated process for the production of grass biomethane.

    PubMed

    Nizami, Abdul-Sattar; Korres, Nicholas E; Murphy, Jerry D

    2009-11-15

    Production of grass biomethane is an integrated process which involves numerous stages with numerous permutations. The grass grown can be of numerous species, and it can involve numerous cuts. The lignocellulosic content of grass increases with maturity of grass; the first cut offers more methane potential than the later cuts. Water-soluble carbohydrates (WSC) are higher (and as such methane potential is higher) for grass cut in the afternoon as opposed to that cut in the morning. The method of ensiling has a significant effect on the dry solids content of the grass silage. Pit or clamp silage in southern Germany and Austria has a solids content of about 40%; warm dry summers allow wilting of the grass before ensiling. In temperate oceanic climates like Ireland, pit silage has a solids content of about 21% while bale silage has a solids content of 32%. Biogas production is related to mass of volatile solids rather than mass of silage; typically one ton of volatile solid produces 300 m(3) of methane. The dry solids content of the silage has a significant impact on the biodigester configuration. Silage with a high solids content would lend itself to a two-stage process; a leach bed where volatile solids are converted to a leachate high in chemical oxygen demand (COD), followed by an upflow anaerobic sludge blanket where the COD can be converted efficiently to CH(4). Alternative configurations include wet continuous processes such as the ubiquitous continuously stirred tank reactor; this necessitates significant dilution of the feedstock to effect a solids content of 12%. Various pretreatment methods may be employed especially if the hydrolytic step is separated from the methanogenic step. Size reduction, thermal, and enzymatic methodologies are used. Good digester design is to seek to emulate the cow, thus rumen fluid offers great potential for hydrolysis.

  10. Modelling Water Uptake Provides a New Perspective on Grass and Tree Coexistence

    PubMed Central

    2015-01-01

    Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize a water movement model (Hydrus 1D). The model accounted for water availability and estimated grass and tree water uptake by depth over a growing season. Most root biomass was found in shallow soils (0–20 cm) and tracer data revealed that, within these shallow depths, half of active grass roots were in the top 12 cm while half of active tree roots were in the top 21 cm. However, because shallow soils provided roots with less water than deep soils (20–90 cm), the water movement model indicated that grass and tree water uptake was twice as deep as would be predicted from root biomass or tracer data alone: half of grass and tree water uptake occurred in the top 23 and 43 cm, respectively. Niche partitioning was also greater when estimated from water uptake rather than tracer uptake. Contrary to long-standing assumptions, shallow grass root distributions absorbed 32% less water than slightly deeper tree root distributions when grasses and trees were assumed to have equal water demands. Quantifying water uptake revealed deeper soil water uptake, greater niche partitioning and greater benefits of deep roots than would be estimated from root biomass or tracer uptake data alone. PMID:26633177

  11. Molecular and functional characterization of an IL-1β receptor antagonist in grass carp (Ctenopharyngodon idella).

    PubMed

    Yao, Fuli; Yang, Xiao; Wang, Xinyan; Wei, He; Zhang, Anying; Zhou, Hong

    2015-04-01

    In the present study, we discovered a novel IL-1 family member (nIL-1F) from grass carp that possessed the ability to bind with grass carp IL-1β receptor type 1 (gcIL-1R1) and attenuate grass carp IL-1β activity in head kidney leukocytes (HKLs), suggesting that it may function as an IL-1β receptor antagonist. Grass carp nIL-1F transcript was constitutively expressed with the highest levels in some lymphoid organs, including head kidney, spleen and intestine, implying its potential in grass carp immunity. In agreement with this notion, in vitro and in vivo studies showed that nIL-1F mRNA was inductively expressed in grass carp with a rapid kinetics, indicating that it may be an early response gene during immune challenges. In addition, recombinant grass carp IL-1β (rgcIL-1β) induced nIL-1F mRNA expression via NF-κB and MAPK (JNK, p38 and p42/44) signaling pathways in HKLs. Particularly, the orthologs of nIL-1F found in other fish species, including zebrafish, pufferfish and rainbow trout are not homologous to mammalian IL-1β receptor antagonist (IL-1Ra), indicating that fish nIL-1F and mammalian IL-1Ra may not share a common evolutionary ancestor. Taken together, our data suggest the existence of a naturally occurring fish nIL-1F, which may function like mammalian IL-1Ra, being beneficial to understand the auto-regulatory mechanism of IL-1β activity in fish immunity. PMID:25475961

  12. Positive Effects of Non-Native Grasses on the Growth of a Native Annual in a Southern California Ecosystem

    PubMed Central

    Pec, Gregory J.; Carlton, Gary C.

    2014-01-01

    Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern California. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern California ecosystem. PMID:25379790

  13. Selenium accumulation and selenium tolerance of salt grass from soils with elevated concentrations of Se and salinity.

    PubMed

    Wu, L; Huang, Z Z

    1991-12-01

    Biomass production, selenium accumulation, and the role of the bioextraction of selenium by salt grass (Distichlis spicata L.) in soils with elevated concentrations of Se and salinity at Kesterson, California, were studied. Salt grass contributed more than 80% vegetative coverage and 90% dry weight in the grassland communities where the soil Se concentrations were 100 times (1000 to 3000 micrograms kg-1) higher than the Se concentrations found in soils of the control sites. No evidence for evolution of Se tolerance was found in the salt grass populations. The successful colonization of salt grass in the soil with elevated Se and salinity is attributable to the presence of high concentrations of soil sulfate. Salt grass accumulated less Se than other salt-tolerant plant species existing in the same area, and no predation of animals and insects on salt grass has been noticed. Salt grass can transpire substantial amounts of volatile Se through its plant tissue. Under field conditions, a 1-m2 salt grass plot may produce 180 micrograms volatile selenium per day. However, no reduction of soil Se concentration in the salt grass habitat was detected over a period of 1 year. A long-term monitoring of Se status is needed in order to make predictions of the effectiveness of efforts to clean up Se-contaminated soils through the use of native plant species.

  14. Positive effects of non-native grasses on the growth of a native annual in a southern california ecosystem.

    PubMed

    Pec, Gregory J; Carlton, Gary C

    2014-01-01

    Fire disturbance is considered a major factor in the promotion of non-native plant species. Non-native grasses are adapted to fire and can alter environmental conditions and reduce resource availability in native coastal sage scrub and chaparral communities of southern California. In these communities persistence of non-native grasses following fire can inhibit establishment and growth of woody species. This may allow certain native herbaceous species to colonize and persist beneath gaps in the canopy. A field manipulative experiment with control, litter, and bare ground treatments was used to examine the impact of non-native grasses on growth and establishment of a native herbaceous species, Cryptantha muricata. C. muricata seedling survival, growth, and reproduction were greatest in the control treatment where non-native grasses were present. C. muricata plants growing in the presence of non-native grasses produced more than twice the number of flowers and more than twice the reproductive biomass of plants growing in the treatments where non-native grasses were removed. Total biomass and number of fruits were also greater in the plants growing in the presence of non-native grasses. Total biomass and reproductive biomass was also greater in late germinants than early germinants growing in the presence of non-native grasses. This study suggests a potential positive effect of non-native grasses on the performance of a particular native annual in a southern California ecosystem.

  15. Overlap in nitrogen sources and redistribution of nitrogen between trees and grasses in a semi-arid savanna.

    PubMed

    Priyadarshini, K V R; Prins, Herbert H T; de Bie, Steven; Heitkönig, Ignas M A; Woodborne, Stephan; Gort, Gerrit; Kirkman, Kevin; Fry, Brian; de Kroon, Hans

    2014-04-01

    A key question in savanna ecology is how trees and grasses coexist under N limitation. We used N stable isotopes and N content to study N source partitioning across seasons from trees and associated grasses in a semi-arid savanna. We also used (15)N tracer additions to investigate possible redistribution of N by trees to grasses. Foliar stable N isotope ratio (δ(15)N) values were consistent with trees and grasses using mycorrhiza-supplied N in all seasons except in the wet season when they switched to microbially fixed N. The dependence of trees and grasses on mineralized soil N seemed highly unlikely based on seasonal variation in mineralization rates in the Kruger Park region. Remarkably, foliar δ(15)N values were similar for all three tree species differing in the potential for N fixation through nodulation. The tracer experiment showed that N was redistributed by trees to understory grasses in all seasons. Our results suggest that the redistribution of N from trees to grasses and uptake of N was independent of water redistribution. Although there is overlap of N sources between trees and grasses, dependence on biological sources of N coupled with redistribution of subsoil N by trees may contribute to the coexistence of trees and grasses in semi-arid savannas.

  16. Turbulence and Dynamics of Wildland Grass Fires: The FireFlux Experiment.

    NASA Astrophysics Data System (ADS)

    Clements, C.; Zhong, S.; Li, J.; Goodrick, S.; Bian, X.; Heilman, W.; Charney, J.; Potter, B.; Aumann, G.

    2006-12-01

    Grass fires, although not as intense as forest fires, present a major threat to life and property in regions of drought in the Great Plains of the United States. Recently, major wildland grass fires in Texas burned nearly 5 million acres and destroyed over 400 homes since December. During the week of 16 March 2006, 11 people were killed and an estimated 10,000 head of livestock were lost, marking this the worst fire season to date for the state of Texas. As an aid to fire management, various models have been developed to describe fire behavior, but observational data in the immediate environment of grass fires are largely unavailable for validating these models. These models also emphasize fuels and fail to consider the role of convective dynamics in fire behavior. To fill this gap, an intensive field measurement campaign called FireFlux was conducted recently near Houston, Texas. The campaign used a variety of instrument platforms to collect mean and turbulence data at multiple levels within and immediately downwind of a 155 acre tall-grass prairie burn unit. The experimental burn was intended to replicate a natural wildland grass fire as closely as possible. Fire ignition occurred upwind, and the fire was allowed to spread through the instrumentation. Preliminary analyses show combustion-zone temperatures exceeding 920 °C and vertical velocities exceeding 5 m s-1. These data are being used to understand the dynamic behavior of grass fires and to validate fire-behavior models used by fire managers and fire fighters. The intended purpose of this proposed article is to report on the recent FireFlux experiment, including its experimental goals, design, instrumentation, and preliminary results. The results include new findings and first time observations of atmospheric turbulence structures and turbulent fluxes associated with intense grass fires. The article is timely because of the extreme grass fires that caused loss of life in Texas and Oklahoma during the 2005

  17. Feasibility of an implantable capsule for limiting lifespan of grass carp

    USGS Publications Warehouse

    Thomas, R.M.; Miranda, L.E.; Kirk, J.P.

    2006-01-01

    The grass carp (Ctenopharyngodon idella) is an herbivorous cyprinid stocked to control undesirable aquatic vegetation. However, stocking grass carp presents several problems including complete eradication of submersed aquatic vegetation, dispersal out of the target area, adverse effects on fish communities, and damage to waterfowl habitat and native vegetation. The purpose of this research was to consider the feasibility of an implantable capsule for limiting the lifespan of grass carp. Stainless steel dowel pins were inserted into 49 fish to identify the most appropriate site to implant the capsule. The throat region along the body's longitudinal axis was identified as the most suitable location because it resulted in minimal loss over an 8-month holding period. Rotenone solutions were injected into the ventral surface between the pelvic fins to determine the lethal dosage to 95% of the population (LD 95). The LD95 for grass carp increased curvilin-early with fish weight. Four polymers that merit further evaluation in constructing the capsule are poly[bis(p-carboxyphenoxy) propane anhydride], poly[bis(p- carboxyphenoxy) hexane anhydride], poly-1-lactide, and poly(??-caprolactone) . Implants are commonly used to deliver pharmaceutical products in medical and veterinarian applications, and have been used in fish. Developing a bioerodible capsule could increase the safety and flexibility of stocking grass carp for control of aquatic plants, and may also be applicable for management of other exotic species.

  18. Form and function of grass ring patterns in arid grasslands: the role of abiotic controls.

    PubMed

    Ravi, Sujith; D'Odorico, Paolo; Wang, Lixin; Collins, Scott

    2008-12-01

    Ring-shaped growth patterns commonly occur in resource-limited arid and semi-arid environments. The spatial distribution, geometry, and scale of vegetation growth patterns result from interactions between biotic and abiotic processes, and, in turn, affect the spatial patterns of soil moisture, sediment transport, and nutrient dynamics in aridland ecosystems. Even though grass ring patterns are observed worldwide, a comprehensive understanding of the biotic and abiotic processes that lead to the formation, growth and breakup of these rings is still lacking. Our studies on patterns of infiltration and soil properties of blue grama (Bouteloua gracilis) grass rings in the northern Chihuahuan desert indicate that ring patterns result from the interaction between clonal growth mechanisms and abiotic factors such as hydrological and aeolian processes. These processes result in a negative feedback between sediment deposition and vegetation growth inside the bunch grass, which leads to grass die back at the center of the grass clump. We summarize these interactions in a simple theoretical and conceptual model that integrates key biotic and abiotic processes in ring formation, growth and decline.

  19. Treatment of domestic wastewater by vertical flow constructed wetland planted with umbrella sedge and Vetiver grass.

    PubMed

    Kantawanichkul, Suwasa; Sattayapanich, Somsiri; van Dien, Frank

    2013-01-01

    The aim of this study was to investigate the efficiency of wastewater treatment by vertical flow constructed wetland systems under different hydraulic loading rates (HLR). The comparison of two types of plants, Cyperus alternifolius (Umbrella sedge) and Vetiveria zizanioides (Vetiver grass), was also conducted. In this study, six circular concrete tanks (diameter 0.8 m) were filled with fine sand and gravel to the depth of 1.23 m. Three tanks were planted with Umbrella sedge and the other three tanks were planted with Vetiver grass. Settled domestic wastewater from Chiang Mai University (chemical oxygen demand (COD), NH4(+)-N and suspended solids (SS) of 127.1, 27.4 and 29.5 mg/L on average, respectively) was intermittently applied for 45 min and rested for 3 h 15 min. The HLR of each tank was controlled at 20, 29 and 40 cm/d. It was found that the removal efficiency of the Umbrella sedge systems was higher than the Vetiver grass systems for every parameter, and the lowest HLR provided the maximum treatment efficiency. The removal efficiency of COD and nitrogen in terms of total Kjeldahl nitrogen (TKN) was 76 and 65% at 20 cm/d HLR for Umbrella sedge compared to only 67 and 56% for Vetiver grass. Nitrogen accumulation in plant biomass was also higher in Umbrella sedge than in Vetiver grass in every HLR. Umbrella sedge was thus proved to be a suitable constructed wetland plant in tropical climates.

  20. Endophytic Epichloë species and their grass hosts: from evolution to applications.

    PubMed

    Saikkonen, Kari; Young, Carolyn A; Helander, Marjo; Schardl, Christopher L

    2016-04-01

    The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.

  1. Adverse reactions to immunotherapy are associated with different patterns of sensitization to grass allergens.

    PubMed

    Sastre, J; Rodríguez, F; Campo, P; Laffond, E; Marín, A; Alonso, M D

    2015-05-01

    The aim of the study was to investigate whether adverse drug reactions (ADRs) during immunotherapy with a grass extract (AVANZ® Phleum, ALK-Abelló) are related to the different patterns of sensitization of patients to grass allergens. A total of 192 patients with rhinitis and/or asthma sensitized to grass pollen received a 4-week updosing with five injections. ADRs were evaluated following EAACI guidelines. A total of 432 ADRs in 133 (69%) patients were recorded, 64% local and 31% systemic. There was a significant association between the number of grass allergens that sensitized the patients and the total number of ADRs (P = 0.004) occurred locally (P = 0.003) and systemically (P = 0.01). Sensitization to Phl p1 + Phl p5 or Phl p1 + Phl p5 + Phl p12 was significantly associated with a higher frequency of local or systemic reactions (P = 0.001, both). Different patterns of sensitization to grass allergens may potentially be considered a risk marker to the development of ADRs to immunotherapy.

  2. Recovery of tall cotton-grass following real and simulated feeding by snow geese

    USGS Publications Warehouse

    Hupp, J.W.; Robertson, Donna G.; Schmutz, J.A.

    2000-01-01

    Lesser snow geese Anser caerulescens caerulescens from the western Canadian Arctic feed on underground parts of tall cotton-grass Eriophorum angustifolium during autumn staging on the coastal plain of the Beaufort Sea in Canada and Alaska. We studied revegetation of sites where cotton-grass had been removed either by human-imprinted snow geese or by hand to simulate snow goose feeding. Aerial cover of cotton-grass at sites (n = 4) exploited by human-imprinted snow geese averaged 60 and 39% lower than in undisturbed control plots during the first and second year after feeding, respectively. Underground biomass of cotton-grass stembases and rhizomes in hand-treated plots was 80 and 62% less than in control plots 2 and 4 yr after removal, respectively (n = 10 yr-1). Aerial cover and biomass of common non-forage species such as Carex aquatilis did not increase on treated areas. Removal of cotton-grass by geese likely reduces forage availability at exploited sites for at least 2-4 yr after feeding but probably does not affect long-term community composition. Temporal heterogeneity in forage abundance likely contributes to the large spatial requirement of snow geese during staging.

  3. Analogous reserve distribution and tissue characteristics in quinoa and grass seeds suggest convergent evolution.

    PubMed

    Burrieza, Hernán P; López-Fernández, María P; Maldonado, Sara

    2014-01-01

    Quinoa seeds are highly nutritious due to the quality of their proteins and lipids and the wide range of minerals and vitamins they store. Three compartments can be distinguished within the mature seed: embryo, endosperm, and perisperm. The distribution of main storage reserves is clearly different in those areas: the embryo and endosperm store proteins, lipids, and minerals, and the perisperm stores starch. Tissues equivalent (but not homologous) to those found in grasses can be identified in quinoa, suggesting the effectiveness of this seed reserve distribution strategy; as in cells of grass starchy endosperm, the cells of the quinoa perisperm endoreduplicate, increase in size, synthesize starch, and die during development. In addition, both systems present an extra-embryonic tissue that stores proteins, lipids and minerals: in gramineae, the aleurone layer(s) of the endosperm; in quinoa, the micropylar endosperm; in both cases, the tissues are living. Moreover, the quinoa micropylar endosperm and the coleorhiza in grasses play similar roles, protecting the root in the quiescent seed and controlling dormancy during germination. This investigation is just the beginning of a broader and comparative study of the development of quinoa and grass seeds. Several questions arise from this study, such as: how are synthesis and activation of seed proteins and enzymes regulated during development and germination, what are the genes involved in these processes, and lastly, what is the genetic foundation justifying the analogy to grasses. PMID:25360139

  4. Cyathostomin larvae: presence on Brachiaria humidicola grass during the rainy and dry seasons of Brazil.

    PubMed

    dos Santos, Claudia Navarro; de Souza, Luciene Soares; Vieira, Vivian Suane de Freitas; Pinheiro, Jairo; Rodrigues, Maria de Lurdes de Azevedo

    2012-01-01

    The presence of cyathostomin larvae is directly associated to climatic conditions of each region. This study aimed to evaluate the ecology of infective larvae on Brachiaria humidicola during the dry and rainy seasons from October 2007 to September 2008 in a tropical region, Rio de Janeiro state, southeastern Brazil. Stools were collected from the rectum of horses naturally infected with cyathostomins at the beginning of the rainy season (October to March) and dry season (April to September). They were divided into four samples of 500 g and deposited on a grass patch of B. humidicola. Seven days later and every 15 days thereafter samples of feces and grass were collected and processed by the Baermann technique. The mean number of larvae recovered from the grass varied according to the season, with greater recovery of larvae during the peak of the dry season (14,700 L3.kg-¹ DM). There was a statistically significant difference between L3 recovered from feces and grass, but not between L3 recovered from the grass base and apex. These results show that the region's climate favors the development and survival of infective cyathostomin larvae throughout the year, with a greater number of larvae during the dry season.

  5. The Interplay Between Bioenergy Grass Production and Water Resources in the United States of America.

    PubMed

    Song, Yang; Cervarich, Matthew; Jain, Atul K; Kheshgi, Haroon S; Landuyt, William; Cai, Ximing

    2016-03-15

    We apply a land surface model to evaluate the interplay between potential bioenergy grass (Miscanthus, Cave-in-Rock, and Alamo) production, water quantity, and nitrogen leaching (NL) in the Central and Eastern U.S. Water use intensity tends to be lower where grass yields are modeled to be high, for example in the Midwest for Miscanthus and Cave-in-Rock and the upper southeastern U.S. for Alamo. However, most of these regions are already occupied by crops and forests and substitution of these biome types for ethanol production implies trade-offs. In general, growing Miscanthus consumes more water, Alamo consumes less water, and Cave-in-Rock consumes approximately the same amount of water as existing vegetation. Bioenergy grasses can maintain high productivity over time, even in water limited regions, because their roots can grow deeper and extract the water from the deep, moist soil layers. However, this may not hold where there are frequent and intense drought events, particularly in regions with shallow soil depths. One advantage of bioenergy grasses is that they mitigate nitrogen leaching relative to row crops and herbaceous plants when grown without applying N fertilizer; and bioenergy grasses, especially Miscanthus, generally require less N fertilizer application than row crops and herbaceous plants.

  6. The Interplay Between Bioenergy Grass Production and Water Resources in the United States of America.

    PubMed

    Song, Yang; Cervarich, Matthew; Jain, Atul K; Kheshgi, Haroon S; Landuyt, William; Cai, Ximing

    2016-03-15

    We apply a land surface model to evaluate the interplay between potential bioenergy grass (Miscanthus, Cave-in-Rock, and Alamo) production, water quantity, and nitrogen leaching (NL) in the Central and Eastern U.S. Water use intensity tends to be lower where grass yields are modeled to be high, for example in the Midwest for Miscanthus and Cave-in-Rock and the upper southeastern U.S. for Alamo. However, most of these regions are already occupied by crops and forests and substitution of these biome types for ethanol production implies trade-offs. In general, growing Miscanthus consumes more water, Alamo consumes less water, and Cave-in-Rock consumes approximately the same amount of water as existing vegetation. Bioenergy grasses can maintain high productivity over time, even in water limited regions, because their roots can grow deeper and extract the water from the deep, moist soil layers. However, this may not hold where there are frequent and intense drought events, particularly in regions with shallow soil depths. One advantage of bioenergy grasses is that they mitigate nitrogen leaching relative to row crops and herbaceous plants when grown without applying N fertilizer; and bioenergy grasses, especially Miscanthus, generally require less N fertilizer application than row crops and herbaceous plants. PMID:26866460

  7. Effects of river flooding on polybrominated diphenyl ether (PBDE) levels in cows' milk, soil, and grass.

    PubMed

    Lake, Iain R; Foxall, Christopher D; Fernandes, Alwyn; Lewis, Mervyn; Rose, Martin; White, Oliver; Dowding, Alan

    2011-06-01

    The first investigation into PBDE levels in food produced from flood-prone land on industrial river catchments was conducted. In August 2008 samples of cows' milk, along with grass and soil were taken from 5 pairs of flood-prone and control farms on the River Trent (Central UK). The sum of 7 BDE congeners (28, 47, 99, 100, 153, 154, and 183) was calculated. Higher PBDE levels occurred in soil on flood-prone compared to control farms (median 770 vs 280 ng/kg dry weight). These higher levels were not reflected in the grass samples indicating that PBDE contamination on soils is not transferred efficiently to grass. This observation alongside the fact that cows on flood-prone farms spend time on non-flood-prone land and are fed substantial quantities of commercial feed are reasons why higher PBDE levels were not found in milk from flood-prone farms (median 300 vs 250 ng/kg fat weight). Similar BDE47/BDE99 ratios were observed in soil and grass samples compared to the PBDE product commonly used in the UK, indicating few differences in source-pathway transfer efficiencies between congeners. The BDE47/BDE99 ratio in the milk samples was greater than those in the grass and feed indicating differential food to milk transfer efficiencies between congeners. PMID:21548556

  8. Treatment of domestic wastewater by vertical flow constructed wetland planted with umbrella sedge and Vetiver grass.

    PubMed

    Kantawanichkul, Suwasa; Sattayapanich, Somsiri; van Dien, Frank

    2013-01-01

    The aim of this study was to investigate the efficiency of wastewater treatment by vertical flow constructed wetland systems under different hydraulic loading rates (HLR). The comparison of two types of plants, Cyperus alternifolius (Umbrella sedge) and Vetiveria zizanioides (Vetiver grass), was also conducted. In this study, six circular concrete tanks (diameter 0.8 m) were filled with fine sand and gravel to the depth of 1.23 m. Three tanks were planted with Umbrella sedge and the other three tanks were planted with Vetiver grass. Settled domestic wastewater from Chiang Mai University (chemical oxygen demand (COD), NH4(+)-N and suspended solids (SS) of 127.1, 27.4 and 29.5 mg/L on average, respectively) was intermittently applied for 45 min and rested for 3 h 15 min. The HLR of each tank was controlled at 20, 29 and 40 cm/d. It was found that the removal efficiency of the Umbrella sedge systems was higher than the Vetiver grass systems for every parameter, and the lowest HLR provided the maximum treatment efficiency. The removal efficiency of COD and nitrogen in terms of total Kjeldahl nitrogen (TKN) was 76 and 65% at 20 cm/d HLR for Umbrella sedge compared to only 67 and 56% for Vetiver grass. Nitrogen accumulation in plant biomass was also higher in Umbrella sedge than in Vetiver grass in every HLR. Umbrella sedge was thus proved to be a suitable constructed wetland plant in tropical climates. PMID:24056433

  9. Microsatellite genetic diversity and differentiation of native and introduced grass carp populations in three continents

    USGS Publications Warehouse

    Chapman, Duane C.; Chen, Qin; Wang, Chenghui; Zhao, Jinlian; Lu, Guoqing; Zsigmond, Jeney; Li, Sifa

    2012-01-01

    Grass carp (Ctenopharyngodon idella), a freshwater species native to China, has been introduced to about 100 countries/regions and poses both biological and environmental challenges to the receiving ecosystems. In this study, we analyzed genetic variation in grass carp from three introduced river systems (Mississippi River Basin in US, Danube River in Hungary, and Tone River in Japan) as well as its native ranges (Yangtze, Pearl, and Amur Rivers) in China using 21 novel microsatellite loci. The allelic richness, observed heterozygosity, and within-population gene diversity were found to be lower in the introduced populations than in the native populations, presumably due to the small founder population size of the former. Significant genetic differentiation was found between all pairwise populations from different rivers. Both principal component analysis and Bayesian clustering analysis revealed obvious genetic distinction between the native and introduced populations. Interestingly, genetic bottlenecks were detected in the Hungarian and Japanese grass carp populations, but not in the North American population, suggesting that the Mississippi River Basin grass carp has experienced rapid population expansion with potential genetic diversification during the half-century since its introduction. Consequently, the combined forces of the founder effect, introduction history, and rapid population expansion help explaining the observed patterns of genetic diversity within and among both native and introduced populations of the grass carp.

  10. Mapping grass communities based on multi-temporal Landsat TM imagery and environmental variables

    NASA Astrophysics Data System (ADS)

    Zeng, Yuandi; Liu, Yanfang; Liu, Yaolin; de Leeuw, Jan

    2007-06-01

    Information on the spatial distribution of grass communities in wetland is increasingly recognized as important for effective wetland management and biological conservation. Remote sensing techniques has been proved to be an effective alternative to intensive and costly ground surveys for mapping grass community. However, the mapping accuracy of grass communities in wetland is still not preferable. The aim of this paper is to develop an effective method to map grass communities in Poyang Lake Natural Reserve. Through statistic analysis, elevation is selected as an environmental variable for its high relationship with the distribution of grass communities; NDVI stacked from images of different months was used to generate Carex community map; the image in October was used to discriminate Miscanthus and Cynodon communities. Classifications were firstly performed with maximum likelihood classifier using single date satellite image with and without elevation; then layered classifications were performed using multi-temporal satellite imagery and elevation with maximum likelihood classifier, decision tree and artificial neural network separately. The results show that environmental variables can improve the mapping accuracy; and the classification with multitemporal imagery and elevation is significantly better than that with single date image and elevation (p=0.001). Besides, maximum likelihood (a=92.71%, k=0.90) and artificial neural network (a=94.79%, k=0.93) perform significantly better than decision tree (a=86.46%, k=0.83).

  11. Effects of river flooding on polybrominated diphenyl ether (PBDE) levels in cows' milk, soil, and grass.

    PubMed

    Lake, Iain R; Foxall, Christopher D; Fernandes, Alwyn; Lewis, Mervyn; Rose, Martin; White, Oliver; Dowding, Alan

    2011-06-01

    The first investigation into PBDE levels in food produced from flood-prone land on industrial river catchments was conducted. In August 2008 samples of cows' milk, along with grass and soil were taken from 5 pairs of flood-prone and control farms on the River Trent (Central UK). The sum of 7 BDE congeners (28, 47, 99, 100, 153, 154, and 183) was calculated. Higher PBDE levels occurred in soil on flood-prone compared to control farms (median 770 vs 280 ng/kg dry weight). These higher levels were not reflected in the grass samples indicating that PBDE contamination on soils is not transferred efficiently to grass. This observation alongside the fact that cows on flood-prone farms spend time on non-flood-prone land and are fed substantial quantities of commercial feed are reasons why higher PBDE levels were not found in milk from flood-prone farms (median 300 vs 250 ng/kg fat weight). Similar BDE47/BDE99 ratios were observed in soil and grass samples compared to the PBDE product commonly used in the UK, indicating few differences in source-pathway transfer efficiencies between congeners. The BDE47/BDE99 ratio in the milk samples was greater than those in the grass and feed indicating differential food to milk transfer efficiencies between congeners.

  12. An extract of Timothy-grass pollen used as sublingual immunotherapy for summer hay fever.

    PubMed

    Kay, A B

    2007-12-01

    Grazax is a lyophilisate of an extract of Timothy-grass pollen (Phleum pratense) administered by the sublingual route to induce desensitization (or hyposensitization) to grass pollen in subjects with hay fever. Since allergen avoidance measures are limited in hay fever sufferers, present treatment, at least in the United Kingdom, is almost always by symptomatic medication. The effectiveness of symptomatic treatment in hay fever is variable and depends on patient compliance and the judicious prescribing of antihistamines and anti-inflammatory preparations either alone or in combination. Desensitization (hyposensitization or specific immunotherapy) by subcutaneous injection has been shown to be very efficacious and is used for patients who do not adequately respond to drug treatment. A rare side effect of desensitizing injections is anaphylaxis, and so use is limited to specialized centers. For these reasons there has been considerable interest in specific immunotherapy by the sublingual route. Grazax has recently been approved in the United Kingdom. It is commenced at least four months prior to the expected start of the grass pollen season and in line with injection immunotherapy treatment will be recommended for a period of three years with annual reviews to assess patient outcomes. Grazax grass allergen tablets are well tolerated in patients with grass pollen allergy with most adverse events being mild local reactions. There have been no instances of anaphylaxis. In randomized double-blind placebo controlled trials Grazax reduces symptoms and medication scores in adults with hay fever. The long-term effects of Grazax are currently being investigated.

  13. Methods to assess factors that influence grass seed yield

    NASA Astrophysics Data System (ADS)

    Louhaichi, Mounir

    A greater than 10-fold increase in Canada goose (Branta canadensis ) populations over the past several years has resulted in concerns over grazing impacts on grass seed production in the mid-Willamette Valley, Oregon. This study was designed to develop methods to quantify and statistically analyze goose-grazing impacts on seed yields of tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.). Yield-mapping-system equipped combines, incorporating global positioning system (GPS) technology, were used to measure and map yields. Image processing of ground-level photography to estimate crop cover and other relevant observations were spatially located via GPS to establish spatial-temporal goose grazing patterns. We sampled each field semi-monthly from mid-winter through spring. Spatially located yield data, soils information, exclosure locations, and grazing patterns were integrated via geographical information system (GIS) technology. To avoid concerns about autocorrelation, a bootstrapping procedure for subsampling spatially contiguous seed yield data was used to organize the data for appropriate use of analysis of variance. The procedure was used to evaluate grazing impacts on seed yield for areas of fields with different soils and with differential timing and intensity of goose grazing activity. We also used a standard paired-plot procedure, involving exclosures and associated plots available for grazing. The combination of spatially explicit photography and yield mapping, integrated with GIS, proved effective in establishing cause-and-effect relationships between goose grazing and seed yield differences. Exclosures were essential for providing nongrazed controls. Both statistical approaches were effective in documenting goose-grazing impacts. Paired-plots were restricted by small size and few numbers and did not capture grazing impacts as effectively as comparison of larger areas to exclosures. Bootstrapping to subsample larger areas of

  14. Increased Gene Expression by the First Intron of Maize Shrunken-1 Locus in Grass Species 1

    PubMed Central

    Vasil, Vimla; Clancy, Maureen; Ferl, Robert J.; Vasil, Indra K.; Hannah, L. Curtis

    1989-01-01

    The first intron of the shrunken-1 (Sh1) locus of maize was incorporated into constructs containing the chloramphenicol acetyltransferase gene (CAT) coupled with the nopaline synthase 3′ polyadenylation signal. Transcription was driven with the 35S promoter of the cauliflower mosaic virus (CaMV) or the Sh1 promoter of maize. Transient gene expression was monitored following electroporation into protoplasts of Panicum maximum (guineagrass), Pennisetum purpureum (napiergrass), or Zea mays (maize). The 1028 base pair intron increased gene expression in cells of each species when transcription was driven with the 35S promoter. Eleven to 91-fold increases were observed. Expression levels observed in maize were two and eight times those observed in napiergrass and guineagrass, respectively. The 35S promoter gave CAT activity 10 to 100 times that observed with the Sh1 promoter. Whereas expression driven by the 35S promoter was reproducible, that observed with the Sh1 promoter proved quite variable. In similar constructs the first intron of the alcohol dehydrogenase-1 (Adh1) gene of maize led to increased gene expression of only 7 to 10% of that observed with the Sh1 first intron. The increased level of gene expression caused by the Sh1 first intron is approximately 10 times higher than that caused by any other plant introns that have been used. Thus, the Sh1 first intron may prove quite useful in increasing expression of foreign genes in monocots and possibly other plants. Images Figure 2 PMID:16667219

  15. Remote sensing of submerged aquatic vegetation in the lower Chesapeake Bay. [(sea grasses)

    NASA Technical Reports Server (NTRS)

    Orth, R. J.; Gordon, H. R.

    1975-01-01

    An experimental water penetration film and black and white near infrared film were used to study the distribution of submerged aquatic vegetation in the lower Chesapeake Bay. Detailed description of the grass beds was obtained by flying at an altitude of 5,000 feet, at low tide when wind conditions were minimal. Results show that there was a 36% reduction in the amount of submerged aquatic vegetation in the lower Chesapeake Bay from 1971 to 1974, the greatest losses occurring in the York, Piankatank and Rappahannock rivers (tabulated data is given). Recovery of some grass beds occurs primarily through seedling recruitment and subsequent vegetative growth. Cownose rays are suspected as a main factor for the decimation of some of the grass beds. Maps and photographs of the areas studied are given.

  16. Critical appraisal of Timothy grass pollen extract GRAZAX in the management of allergic rhinitis.

    PubMed

    Scaparrotta, Alessandra; Attanasi, Marina; Petrosino, Marianna I; Di Filippo, Paola; Di Pillo, Sabrina; Chiarelli, Francesco

    2015-01-01

    Allergic rhinitis is one of the most common diseases of adult and pediatric age, associated with grass pollen (GP) allergy in >50% cases, with a consistent impact on quality of life of affected patients. A grass allergen tablet, containing standardized extract derived from Timothy grass (Phleum pratense) pollen and ~15 μg major allergen P. pratense (rPhl p 5), may be the future of allergen-specific immunotherapy (IT) for GP allergy. The aim of this review was to critically evaluate the role of Timothy GP extract IT for the management of allergic rhinitis. For this purpose, we have tried to analyze potential mechanisms of action at the basis of Timothy GP extract, we have reviewed efficacy studies to establish potential benefits and clinical response, and we have also evaluated safety and tolerability profiles and patient focus perspective, such as quality of life, satisfaction and acceptability, and compliance to this IT.

  17. A grass molecular identification system for forensic botany: a critical evaluation of the strengths and limitations.

    PubMed

    Ward, Jodie; Gilmore, Simon R; Robertson, James; Peakall, Rod

    2009-11-01

    Plant material is frequently encountered in criminal investigations but often overlooked as potential evidence. We designed a DNA-based molecular identification system for 100 Australian grasses that consisted of a series of polymerase chain reaction assays that enabled the progressive identification of grasses to different taxonomic levels. The identification system was based on DNA sequence variation at four chloroplast and two mitochondrial loci. Seventeen informative indels and 68 single-nucleotide polymorphisms were utilized as molecular markers for subfamily to species-level identification. To identify an unknown sample to subfamily level required a minimum of four markers or nine markers for species identification. The accuracy of the system was confirmed by blind tests. We have demonstrated "proof of concept" of a molecular identification system for trace botanical samples. Our evaluation suggests that the adoption of a system that combines this approach with DNA sequencing could assist the morphological identification of grasses found as forensic evidence.

  18. CO2 and Er:YAG laser interaction with grass tissues

    NASA Astrophysics Data System (ADS)

    Kim, Jaehun; Ki, Hyungson

    2013-01-01

    Plant leaves are multi-component optical materials consisting of water, pigments, and dry matter, among which water is the predominant constituent. In this article, we investigate laser interaction with grass using CO2 and Er:YAG lasers theoretically and experimentally, especially targeting water in grass tissues. We have first studied the optical properties of light absorbing constituents of grass theoretically, and then have identified interaction regimes and constructed interaction maps through a systematic experiment. Using the interaction maps, we have studied how interaction regimes change as process parameters are varied. This study reveals some interesting findings concerning carbonization and ablation mechanisms, the effect of laser beam diameter, and the ablation efficiency and quality of CO2 and Er:YAG lasers.

  19. Nitrogen removal and water microbiota in grass carp culture following supplementation with Bacillus licheniformis BSK-4.

    PubMed

    Liang, Quan; Zhang, Xiaoping; Lee, Khui Hung; Wang, Yibing; Yu, Kan; Shen, Wenying; Fu, Luoqin; Shu, Miaoan; Li, Weifen

    2015-11-01

    This experiment was designed to study the effects of Bacillus licheniformis BSK-4 on nitrogen removal and microbial community structure in a grass carp (Ctenopharyngodon idellus) culture. The selected strain Bacillus licheniformis BSK-4 significantly decreased nitrite, nitrate and total nitrogen levels in water over an extended, whereas increased ammonia level. Pyrosequencing showed that Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes were dominant in grass carp culture water. Compared with the control group, the number of Proteobacteria and Firmicutes were increased, while Actinobacteria and Bacteroidetes decreased in treatment group. At the genus level, some genera, such as Bacillus, Prosthecobacter, Enterococcus, etc., appear only in the treatment, while many other genera exist only in the control group; Lactobacillus, Luteolibacter, Phenylobacterium, etc. were increased in treatment group compared to those in control group. As above, the results suggested that supplementation with B. licheniformis BSK-4 could remove some nitrogen and cause alterations of the microbial composition in grass carp water.

  20. Cytogenotoxicity of Cymbopogon citratus (DC) Stapf (lemon grass) aqueous extracts in vegetal test systems.

    PubMed

    Sousa, Saulo M; Silva, Pâmela S; Viccini, Lyderson F

    2010-06-01

    The lemon grass, Cymbopogon citratus (DC) Stapf, is an important species of Poaceae family commonly used in the folk medicine in many countries. The aim of this study was to investigate the cytotoxic and genotoxic effects of aqueous extracts from C. citratus leaves on Lactuca sativa (lettuce) root tip meristem cells by cytogenetic studies that have never been done before for lemon grass extracts. For this, lettuce seeds were treated for 72h with different concentrations of lemon grass aqueous extracts (5; 10; 20 and 30 mg/mL). The percentage of germination, root development and cellular behavior were analyzed, and the results showed that the highest concentration of aqueous extracts reduced the mitotic index, the seed germination and the root development of lettuce. The extracts have also induced chromosome aberrations and cellular death in the roots cells of L. sativa. PMID:20563411