WorldWideScience

Sample records for perennial ryegrass based

  1. Genomic prediction in families of perennial ryegrass based on genotyping-by-sequencing

    DEFF Research Database (Denmark)

    Ashraf, Bilal

    In this thesis we investigate the potential for genomic prediction in perennial ryegrass using genotyping-by-sequencing (GBS) data. Association method based on family-based breeding systems was developed, genomic heritabilities, genomic prediction accurancies and effects of some key factors wer...... explored. Results show that low sequencing depth caused underestimation of allele substitution effects in GWAS and overestimation of genomic heritability in prediction studies. Other factors susch as SNP marker density, population structure and size of training population influenced accuracy of genomic...... prediction. Overall, GBS allows for genomic prediction in breeding families of perennial ryegrass and holds good potential to expedite genetic gain and encourage the application of genomic prediction...

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

    Science.gov (United States)

    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.

  3. Genetic markers for flowering in perennial ryegrass

    DEFF Research Database (Denmark)

    Paina, Cristiana; Byrne, Stephen; Andersen, Jeppe Reitan

    2011-01-01

    Perennial ryegrass (Lolium perenne L.) is the principal forage grass utilized in Danish agriculture and underpins the beef and dairy sectors. It is characterized as having high digestibility, high nutritional value, and high productivity during vegetative growth. However, at the reproductive growth...... genes will be converted to molecular markers and mapped in an existing mapping population previously characterized for flowering time and vernalization response. References: Amasino, R.M., Michaels S.D. (2010). The Timing of Flowering. Plant Physiology 154: 516–520 Greenup, A., W. Peacock, W.J., Dennis...

  4. Determination of microbial protein in perennial ryegrass silage

    NARCIS (Netherlands)

    Driehuis, F.; Wikselaar, van P.G.

    2001-01-01

    The microbial matter fraction was determined in perennial ryegrass silages of different dry-matter (DM) contents, ensiled with or without Lactobacillus plantarum. 15N-Leucine and the bacterial cell wall constituent diaminopimelic acid (DAPA) were used as markers for microbial-N. Perennial ryegrass

  5. A transcriptome map of perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Studer Bruno

    2012-04-01

    strategies. Moreover, the high density genetic linkage map predominantly based on gene-associated DNA markers provides an important tool for the assignment of candidate genes to quantitative trait loci (QTL, functional genomics and the integration of genetic and physical maps in perennial ryegrass, one of the most important temperate grassland species.

  6. The Perennial Ryegrass GenomeZipper – Targeted Use of Genome Resources for Comparative Grass Genomics

    DEFF Research Database (Denmark)

    Pfeiffer, Matthias; Martis, Mihaela; Asp, Torben

    2013-01-01

    (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......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...... 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...

  7. The Perennial Ryegrass GenomeZipper: Targeted Use of Genome Resources for Comparative Grass Genomics1[C][W

    Science.gov (United States)

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

    2013-01-01

    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. PMID:23184232

  8. The genome and transcriptome of perennial ryegrass mitochondria

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul; Studer, Bruno; Byrne, Stephen

    2013-01-01

    Background: Perennial ryegrass (Lolium perenne L.) is one of the most important forage and turf grass species of temperate regions worldwide. Its mitochondrial genome is inherited maternally and contains genes that can influence traits of agricultural importance. Moreover, the DNA sequence...... and annotation of the complete mitochondrial genome from perennial ryegrass. Results: Intact mitochondria from perennial ryegrass leaves were isolated and used for mtDNA extraction. The mitochondrial genome was sequenced to a 167-fold coverage using the Roche 454 GS-FLX Titanium platform, and assembled...... of mitochondrial genomes has been established and compared for a large number of species in order to characterize evolutionary relationships.Therefore, it is crucial to understand the organization of the mitochondrial genome and how it varies between and within species. Here, we report the first de novo assembly...

  9. Genomics-Assisted Exploitation of Heterosis in Perennial Ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul

    ryegrass for the development of improved varieties. During his PhD studies, Mohammad Shofiqul Islam studied the feasibility of developing novel hybrid breeding schemes based on cytoplasmic male sterility (CMS) systems in perennial ryegrass. He successfully completed the assembly and annotation of a male......-fertile perennial ryegrass mitochondrial genome, and identified candidate genes responsible for the CMS phenotype by comparing male-fertile and male-sterile mitochondrial genomes. His findings constitute a good basis for continuing research to produce hybrid grass varieties to address the future needs......, breeding activities have been carried out to improve the population and develop synthetic varieties. This does not fully exploit the potential of heterosis, however. Hybrid breeding is an alternative strategy and provides opportunities to fully exploit the genetically available heterosis in perennial...

  10. Association of Candidate Genes With Submergence Response in Perennial Ryegrass

    Directory of Open Access Journals (Sweden)

    Xicheng Wang

    2017-05-01

    Full Text Available Perennial ryegrass is a popular cool-season grass species due to its high quality for forage and turf. The objective of this study was to identify associations of candidate genes with growth and physiological traits to submergence stress and recovery after de-submergence in a global collection of 94 perennial ryegrass accessions. Accessions varied largely in leaf color, plant height (HT, leaf fresh weight (LFW, leaf dry weight (LDW, and chlorophyll fluorescence (Fv/Fm at 7 days of submergence and in HT, LFW and LDW at 7 days of recovery in two experiments. Among 26 candidate genes tested by various models, single nucleotide polymorphisms (SNPs in 10 genes showed significant associations with traits including 16 associations for control, 10 for submergence, and 8 for recovery. Under submergence, Lp1-SST encoding sucrose:sucrose 1-fructosyltransferase and LpGA20ox encoding gibberellin 20-oxidase were associated with LFW and LDW, and LpACO1 encoding 1-aminocyclopropane-1-carboxylic acid oxidase was associated with LFW. Associations between Lp1-SST and HT, Lp6G-FFT encoding fructan:fructan 6G-fructosyltransferase and Fv/Fm, LpCAT encoding catalase and HT were also detected under submergence stress. Upon de-submergence, Lp1-SST, Lp6G-FFT, and LpPIP1 encoding plasma membrane intrinsic protein type 1 were associated with LFW or LDW, while LpCBF1b encoding C-repeat binding factor were associated with HT. Nine significant SNPs in Lp1-SST, Lp6G-FFT, LpCAT, and LpACO1 resulted in amino acid changes with five substitutions found in Lp1-SST under submergence or recovery. The results indicated that allelic diversity in genes involved in carbohydrate and antioxidant metabolism, ethylene and gibberellin biosynthesis, and transcript factor could contribute to growth variations in perennial ryegrass under submergence stress and recovery after de-submergence.

  11. Perennial ryegrass for dairy cows: effects of cultivar on herbage intake during grazing

    NARCIS (Netherlands)

    Smit, H.J.

    2005-01-01

    Keywords:Perennial ryegrass, Lolium perenne , sward morphology, sward cutting, n-alkanes, herbage intake, selection, preference.Perennial ryegrass ( Lolium perenne L.) is the most important species for feeding dairy cows. The majority of the farmers in the Netherlands graze their

  12. De novo assembly of the perennial ryegrass transcriptome using an RNA-Seq strategy.

    Directory of Open Access Journals (Sweden)

    Jacqueline D Farrell

    Full Text Available Perennial ryegrass is a highly heterozygous outbreeding grass species used for turf and forage production. Heterozygosity can affect de-Bruijn graph assembly making de novo transcriptome assembly of species such as perennial ryegrass challenging. Creating a reference transcriptome from a homozygous perennial ryegrass genotype can circumvent the challenge of heterozygosity. The goals of this study were to perform RNA-sequencing on multiple tissues from a highly inbred genotype to develop a reference transcriptome. This was complemented with RNA-sequencing of a highly heterozygous genotype for SNP calling.De novo transcriptome assembly of the inbred genotype created 185,833 transcripts with an average length of 830 base pairs. Within the inbred reference transcriptome 78,560 predicted open reading frames were found of which 24,434 were predicted as complete. Functional annotation found 50,890 transcripts with a BLASTp hit from the Swiss-Prot non-redundant database, 58,941 transcripts with a Pfam protein domain and 1,151 transcripts encoding putative secreted peptides. To evaluate the reference transcriptome we targeted the high-affinity K+ transporter gene family and found multiple orthologs. Using the longest unique open reading frames as the reference sequence, 64,242 single nucleotide polymorphisms were found. One thousand sixty one open reading frames from the inbred genotype contained heterozygous sites, confirming the high degree of homozygosity.Our study has developed an annotated, comprehensive transcriptome reference for perennial ryegrass that can aid in determining genetic variation, expression analysis, genome annotation, and gene mapping.

  13. Ergot alkaloid intoxication in perennial ryegrass (Lolium perenne): an emerging animal health concern in Ireland?

    Science.gov (United States)

    Canty, Mary J; Fogarty, Ursula; Sheridan, Michael K; Ensley, Steve M; Schrunk, Dwayne E; More, Simon J

    2014-01-01

    Four primary mycotoxicosis have been reported in livestock caused by fungal infections of grasses or cereals by members of the Clavicipitaceae family. Ergotism (generally associated with grasses, rye, triticale and other grains) and fescue toxicosis (associated with tall fescue grass, Festuca arundinacea) are both caused by ergot alkaloids, and referred to as 'ergot alkaloid intoxication'. Ryegrass staggers (associated with perennial ryegrass Lolium perenne) is due to intoxication with an indole-diperpene, Lolitrem B, and metabolites. Fescue-associated oedema, recently described in Australia, may be associated with a pyrrolizidine alkaloid, N-acetyl norloline. Ergotism, caused by the fungus Claviceps purpurea, is visible and infects the outside of the plant seed. Fescue toxicosis and ryegrass staggers are caused by Neotyphodium coenophalium and N. lolii, respectively. Fescue-associated oedema has been associated with tall fescue varieties infected with a specific strain of N. coenophialum (AR542, Max P or Max Q). The name Neotyphodium refers to asexual derivatives of Epichloë spp., which have collectively been termed the epichloë fungi. These fungi exist symbiotically within the grass and are invisible to the naked eye. The primary toxicological effect of ergot alkaloid involves vasoconstriction and/or hypoprolactinaemia. Ingestion of ergot alkaloid by livestock can cause a range of effects, including poor weight gain, reduced fertility, hyperthermia, convulsions, gangrene of the extremities, and death. To date there are no published reports, either internationally or nationally, reporting ergot alkaloid intoxication specifically associated with perennial ryegrass endophytes. However, unpublished reports from the Irish Equine Centre have identified a potential emerging problem of ergot alkaloid intoxication with respect to equines and bovines, on primarily perennial ryegrass-based diets. Ergovaline has been isolated in varying concentrations in the herbage of a

  14. Transcriptional Profiling and Identification of Heat-Responsive Genes in Perennial Ryegrass by RNA-Sequencing

    Directory of Open Access Journals (Sweden)

    Kehua Wang

    2017-06-01

    Full Text Available Perennial ryegrass (Lolium perenne is one of the most widely used forage and turf grasses in the world due to its desirable agronomic qualities. However, as a cool-season perennial grass species, high temperature is a major factor limiting its performance in warmer and transition regions. In this study, a de novo transcriptome was generated using a cDNA library constructed from perennial ryegrass leaves subjected to short-term heat stress treatment. Then the expression profiling and identification of perennial ryegrass heat response genes by digital gene expression analyses was performed. The goal of this work was to produce expression profiles of high temperature stress responsive genes in perennial ryegrass leaves and further identify the potentially important candidate genes with altered levels of transcript, such as those genes involved in transcriptional regulation, antioxidant responses, plant hormones and signal transduction, and cellular metabolism. The de novo assembly of perennial ryegrass transcriptome in this study obtained more total and annotated unigenes compared to previously published ones. Many DEGs identified were genes that are known to respond to heat stress in plants, including HSFs, HSPs, and antioxidant related genes. In the meanwhile, we also identified four gene candidates mainly involved in C4 carbon fixation, and one TOR gene. Their exact roles in plant heat stress response need to dissect further. This study would be important by providing the gene resources for improving heat stress tolerance in both perennial ryegrass and other cool-season perennial grass plants.

  15. Inter-simple sequence repeat (ISSR) loci mapping in the genome of perennial ryegrass

    DEFF Research Database (Denmark)

    Pivorienė, O; Pašakinskienė, I; Brazauskas, G

    2008-01-01

    The aim of this study was to identify and characterize new ISSR markers and their loci in the genome of perennial ryegrass. A subsample of the VrnA F2 mapping family of perennial ryegrass comprising 92 individuals was used to develop a linkage map including inter-simple sequence repeat markers...... demonstrated a 70% similarity to the Hordeum vulgare germin gene GerA. Inter-SSR mapping will provide useful information for gene targeting, quantitative trait loci mapping and marker-assisted selection in perennial ryegrass....

  16. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    DEFF Research Database (Denmark)

    Tomaszewski, Céline; Byrne, Stephen; Foito, Alexandra

    2012-01-01

    Perennial ryegrass is the principal forage grass species used in temperate agriculture. In recent years, significant efforts have been made to develop molecular marker strategies to allow cost-effective characterization of a large number of loci simultaneously. One such strategy involves using DAr......T markers, and a DArT array has recently been developed for the Lolium-Festuca complex. In this study, we report the first use of the DArTFest array to generate a genetic linkage map based on 326 markers in a Lolium perenne F2 population, consisting of 325 genotypes. For proof of concept, the map was used...

  17. Quantitative Trait Locus (QTL meta-analysis and comparative genomics for candidate gene prediction in perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Shinozuka Hiroshi

    2012-11-01

    Full Text Available Abstract Background In crop species, QTL analysis is commonly used for identification of factors contributing to variation of agronomically important traits. As an important pasture species, a large number of QTLs have been reported for perennial ryegrass based on analysis of biparental mapping populations. Further characterisation of those QTLs is, however, essential for utilisation in varietal improvement programs. Results A bibliographic survey of perennial ryegrass trait-dissection studies identified a total of 560 QTLs from previously published papers, of which 189, 270 and 101 were classified as morphology-, physiology- and resistance/tolerance-related loci, respectively. The collected dataset permitted a subsequent meta-QTL study and implementation of a cross-species candidate gene identification approach. A meta-QTL analysis based on use of the BioMercator software was performed to identify two consensus regions for pathogen resistance traits. Genes that are candidates for causal polymorphism underpinning perennial ryegrass QTLs were identified through in silico comparative mapping using rice databases, and 7 genes were assigned to the p150/112 reference map. Markers linked to the LpDGL1, LpPh1 and LpPIPK1 genes were located close to plant size, leaf extension time and heading date-related QTLs, respectively, suggesting that these genes may be functionally associated with important agronomic traits in perennial ryegrass. Conclusions Functional markers are valuable for QTL meta-analysis and comparative genomics. Enrichment of such genetic markers may permit further detailed characterisation of QTLs. The outcomes of QTL meta-analysis and comparative genomics studies may be useful for accelerated development of novel perennial ryegrass cultivars with desirable traits.

  18. Establishment techniques in under-sown perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Deleuran, Lise C; Boelt, Birte

    2009-01-01

    Establishment methods have proven to be of major importance for grass-seed production. The objective of this research was to test the effect of different sowing techniques on plant establishment and the subsequent seed yield. Perennial ryegrass (Lolium perenne L.) is used as the model grass due...... to its large importance in Danish agriculture. In a three-year trial six different methods of under-sowing of perennial ryegrass in a spring barley cover crop were employed. Perennial ryegrass was either sown directly at different depths within the spring barley (Hordeum vulgare L.) rows or placed 2, 6......, or 12 cm from the spring barley rows. Results of dry-matter yield indicate that the best establishment of the grass occurred when placing the grass 6 or 12 cm from the cover-crop row, and this is of importance in less vigorous grasses. Overall, no seed-yield difference has been observed for perennial...

  19. Effects of chicory/perennial ryegrass swards compared with perennial ryegrass swards on the performance and carcass quality of grazing beef steers.

    Directory of Open Access Journals (Sweden)

    Christina L Marley

    Full Text Available An experiment investigated whether the inclusion of chicory (Cichorium intybus in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne. Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36 were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011 in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass.

  20. Genetic variation, population structure, and linkage disequilibrium in European elite germplasm of perennial ryegrass

    DEFF Research Database (Denmark)

    Brazauskas, Gintaras; Lenk, Ingo; Pedersen, Morten Greve

    2011-01-01

    Perennial ryegrass (Lolium perenne L.) is a highly valued temperate climate grass species grown as forage crop and for amenity uses. Due to its outbreeding nature and recent domestication, a high degree of genetic diversity is expected among cultivars. The aim of this study was to assess the extent...... of linkage disequilibrium (LD) within European elite germplasm and to evaluate the appropriate methodology for genetic association mapping in perennial ryegrass. A high level of genetic diversity was observed in a set of 380 perennial ryegrass elite genotypes when genotyped with 40 SSRs and 2 STS markers...... and occurred within 0.4 cM across European varieties, when population structure was taken into consideration. However, an extended LD of up to 6.6 cM was detected within the variety Aberdart. High genetic diversity and rapid LD decay provide means for high resolution association mapping in elite materials...

  1. Cultivar by environment effects of perennial ryegrass cultivars selected for high water soluble carbohydrates managed under differing precipitation levels

    Science.gov (United States)

    Historic results of perennial ryegrass (Lolium perenne L.) breeding include improved disease resistance, biomass, and nutritional quality. Yet, lack of tolerance to water stress limits its wise use. Recent efforts to increase water soluble carbohydrate (WSC) content in perennial ryegrass may incre...

  2. Testing water-soluble carbohydrate QTL effects in perennial ryegrass (Lolium perenne L.) by marker selection

    NARCIS (Netherlands)

    Turner, L.B.; Farrell, M.; Humphreys, M.O.; Dolstra, O.

    2010-01-01

    Water-soluble carbohydrates (WSC) are an important factor determining the nutritional value of grass forage and development of genetic markers for selection of WSC traits in perennial ryegrass would benefit future breeding programmes. Quantitative trait loci (QTLs) for WSC have been published for an

  3. Cultivar effects of perennial ryegrass on herbage intake by grazing dairy cows

    NARCIS (Netherlands)

    Smit, H.J.

    2006-01-01

    Perennial ryegrass is the most abundant grass species in temperate climates. An increased herbage intake of dairy cows by breeding new cultivars could have a large potential impact on agriculture. The effects of cultivars on sward structure, nutritive value, physical characteristics and disease

  4. Towards in vitro fertilization, gametosomatic cybridization and DNA transfer in perennial ryegrass (Lolium perenne L.)

    NARCIS (Netherlands)

    Maas, van der H.M.

    1994-01-01

    In this thesis, research towards invitro fertilization, gametosomatic cybridization andDNAtransfer in perennial ryegrass ( Loliumperenne L.), the most important forage

  5. The effects of perennial ryegrass and alfalfa on microbial abundance and diversity in petroleum contaminated soil

    International Nuclear Information System (INIS)

    Kirk, Jennifer L.; Klironomos, John N.; Lee, Hung; Trevors, Jack T.

    2005-01-01

    Enhanced rhizosphere degradation uses plants to stimulate the rhizosphere microbial community to degrade organic contaminants. We measured changes in microbial communities caused by the addition of two species of plants in a soil contaminated with 31,000 ppm of total petroleum hydrocarbons. Perennial ryegrass and/or alfalfa increased the number of rhizosphere bacteria in the hydrocarbon-contaminated soil. These plants also increased the number of bacteria capable of petroleum degradation as estimated by the most probable number (MPN) method. Eco-Biolog plates did not detect changes in metabolic diversity between bulk and rhizosphere samples but denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified partial 16S rDNA sequences indicated a shift in the bacterial community in the rhizosphere samples. Dice coefficient matrices derived from DGGE profiles showed similarities between the rhizospheres of alfalfa and perennial ryegrass/alfalfa mixture in the contaminated soil at week seven. Perennial ryegrass and perennial ryegrass/alfalfa mixture caused the greatest change in the rhizosphere bacterial community as determined by DGGE analysis. We concluded that plants altered the microbial population; these changes were plant-specific and could contribute to degradation of petroleum hydrocarbons in contaminated soil. - Plant-specific changes in microbial populations on roots affect degradation of petroleum hydrocarbons in contaminated soil

  6. Genetic linkage mapping in an F2 perennial ryegrass population using DArT markers

    Czech Academy of Sciences Publication Activity Database

    Tomaszewski, C.; Byrne, S. L.; Foito, A.; Kildea, S.; Kopecký, David; Doležel, Jaroslav; Heslop-Harrison, J. S.; Stewart, D.; Barth, S.

    2012-01-01

    Roč. 131, č. 2 (2012), s. 345-349 ISSN 0179-9541 Institutional research plan: CEZ:AV0Z50380511 Keywords : Lolium perenne * perennial ryegrass * genetic map Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.175, year: 2012

  7. Perennial ryegrass for dairy cows: Intake, milk production and nitrogen utilization

    NARCIS (Netherlands)

    Tas, B.M.

    2005-01-01

    Keywords: perennial ryegrass, dairy cows, intake, digestibility milk production, nitrogen utilisation.In the Netherlands, grass is one of the main roughages in the diet of high productive dairy cows. Grass is associated with two main problems: the limited dry matter intake (DMI)

  8. Genetic characterisation of seed yield and fertility traits in perennial ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Studer, Bruno; Jensen, Louise Bach; Hentrup, Stephan

    2008-01-01

    A population. Path analysis partitioned the direct and indirect effects of seed yield components on seed yield per plant. Seed yield per panicle showed the highest effect on total seed yield. The adjusted mean values of each trait and a genetic linkage map consisting of 97 anonymous and 85 gene associated DNA......Seed yield is a trait of major interest for the key grassland species Lolium perenne L. An F2 mapping population of perennial ryegrass (VrnA), recently characterised for vernalisation response, was assessed in a glasshouse for traits related to seed yield based on a lattice design with four...... replications over 2 years. The traits heading date, plant height, length of panicles, number of panicles per plant, seed yield per panicle, flag leaf length, flag leaf width and seed yield per plant revealed repeatabilities ranging from 41 to 76% and a considerable amount of genetic variation in the Vrn...

  9. Fructan metabolism and changes in fructan composition during cold acclimation in perennial ryegrass

    DEFF Research Database (Denmark)

    Abeynayake, Shamila; Etzerodt, Thomas; Jonavičienė, Kristina

    2015-01-01

    . The ecotype ‘Falster’, adapted to cold climates, increased total fructan content and produced more fructans (DP˃7) in the roots than the variety ‘Veyo’, adapted to warmer climates suggesting that accumulation of fructans in roots, especially the high-DP fructans as an adaptive trait for plant recovery after......Perennial ryegrass (Lolium perenne L.) produces high levels of fructans as a mixture of oligomers with different degrees of polymerization (DP). The present study describes the analysis of the compositional changes in the full spectrum of fructan oligomers, fructan distribution between above ground...... biomass (top) and the roots, and the transcription of candidate genes involved in fructan metabolism during cold acclimation in perennial ryegrass variety ‘Veyo’ and ecotype ‘Falster’ from distinct geographical origins. We observed changes in fructan composition and induction of low-DP fructans...

  10. Path and correlation analysis of perennial ryegrass (Lolium perenne L.) seed yield components

    DEFF Research Database (Denmark)

    Abel, Simon; Gislum, René; Boelt, Birte

    2017-01-01

    Maximum perennial ryegrass seed production potential is substantially greater than harvested yields with harvested yields representing only 20% of calculated potential. Similar to wheat, maize and other agriculturally important crops, seed yield is highly dependent on a number of interacting seed...... yield components. This research was performed to apply and describe path analysis of perennial ryegrass seed yield components in relation to harvested seed yields. Utilising extensive yield components which included subdividing reproductive inflorescences into five size categories, path analysis...... was undertaken assuming a unidirectional causal-admissible relationship between seed yield components and harvested seed yield in six commercial seed production fields. Both spikelets per inflorescence and florets per spikelet had a significant (p seed yield; however, total...

  11. Delayed chlorophyll a fluorescence, MR 820, and gas exchange changes in perennial ryegrass under salt stress

    Energy Technology Data Exchange (ETDEWEB)

    Dąbrowski, P., E-mail: piotr_dabrowski@sggw.pl [Department of Environmental Improvement, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Kalaji, M.H., E-mail: hazem@kalaji.pl [Department of Plant Physiology, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); SI TECHNOLOGY Sp. z o. o., Górczewska 226C/26, 01-460 Warsaw (Poland); Baczewska, A.H., E-mail: a.baczewska@obpan.pl [Polish Academy of Sciences Botanical Garden-Center for Biological Diversity Conservation in Powsin, 2 Prawdziwka St., 02-973 Warsaw (Poland); Pawluśkiewicz, B. [Department of Environmental Improvement, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Mastalerczuk, G., E-mail: grazyna_mastalerczuk@sggw.pl [Department of Agronomy, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Borawska-Jarmułowicz, B., E-mail: barbara_borawska_jarmulowicz@sggw.pl [Department of Agronomy, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw (Poland); Paunov, M. [Department Biophysics and Radiobiology, St. Kl. Ohridski Sofia University, 8 Dragan Tsankov Blvd., 1164 Sofia (Bulgaria); Goltsev, V., E-mail: goltsev@biofac.uni-sofia.bg [Department Biophysics and Radiobiology, St. Kl. Ohridski Sofia University, 8 Dragan Tsankov Blvd., 1164 Sofia (Bulgaria)

    2017-03-15

    Perennial ryegrass (Lolium perenne L.) is one of the more popular grass species in Europe. It is commonly used for starting lawns in urban areas, where plant growth is limited by many environmental conditions. The contamination of soils by salt is one of the major problems in urban green areas, as well as in natural areas. The basic aim of this study is to provide a detailed in vivo analysis of the changes in the delayed chlorophyll fluorescence and MR 820 signals (induced by salt stress) of two lawn varieties of perennial ryegrass, and to find out if there are correlations between these parameters and gas exchange. Two lawn varieties of Lolium perenne L. were used: Nira and Roadrunner. Salinization was performed at 8 weeks after sowing by adding NaCl in water solution (0, 0.15, and 0.30 M). There were 8 terms of measurement: 0 h, 24 h, 48 h, 96 h, 144 h, 192 h, 240 h, and 288 h after salinization. Our results showed that delayed fluorescence is a tool that can bring completely new opportunities for detecting stress in plants caused by salt. Our work allowed us to identify various limitation patterns in the photosynthetic efficiency of perennial ryegrass lawn varieties grown under salt stress conditions. Significant differences between the two tested varieties in response to salt stress were confirmed.

  12. Genetic Loci Governing Androgenic Capacity in Perennial Ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Rachel F. Begheyn

    2018-06-01

    Full Text Available Immature pollen can be induced to switch developmental pathways from gametogenesis to embryogenesis and subsequently regenerate into homozygous, diploid plants. Such androgenic production of doubled haploids is particularly useful for species where inbreeding is hampered by effective self-incompatibility systems. Therefore, increasing the generally low androgenic capacity of perennial ryegrass (Lolium perenne L. germplasm would enable the efficient production of homozygous plant material, so that a more effective exploitation of heterosis through hybrid breeding schemes can be realized. Here, we present the results of a genome-wide association study in a heterozygous, multiparental population of perennial ryegrass (n = 391 segregating for androgenic capacity. Genotyping-by-sequencing was used to interrogate gene- dense genomic regions and revealed over 1,100 polymorphic sites. Between one and 10 quantitative trait loci (QTL were identified for anther response, embryo and total plant production, green and albino plant production and regeneration. Most traits were under polygenic control, although a major QTL on linkage group 5 was associated with green plant regeneration. Distinct genetic factors seem to affect green and albino plant recovery. Two intriguing candidate genes, encoding chromatin binding domains of the developmental phase transition regulator, Polycomb Repressive Complex 2, were identified. Our results shed the first light on the molecular mechanisms behind perennial ryegrass microspore embryogenesis and enable marker-assisted introgression of androgenic capacity into recalcitrant germplasm of this forage crop of global significance.

  13. Population structure, genetic variation and linkage disequilibrium in perennial ryegrass populations divergently selected for freezing tolerance

    Directory of Open Access Journals (Sweden)

    Mallikarjuna Rao eKovi

    2015-11-01

    Full Text Available Low temperature is one of the abiotic stresses seriously affecting the growth of perennial ryegrass (Lolium perenne L. Understanding the genetic control of freezing tolerance would aid in the development of cultivars of perennial ryegrass with improved adaptation to frost. A total number of 80 individuals (24 of High frost [HF]; 29 of Low frost [LF] and 27 of Unselected [US] from the second generation of the two divergently selected populations and an unselected control population were genotyped using 278 genome-wide SNPs derived from Lolium perenne L. transcriptome sequence. Our studies showed that the HF and LF populations are very divergent after selection for freezing tolerance, whereas the HF and US populations are more similar. Linkage disequilibrium (LD decay varied across the seven chromosomes and the conspicuous pattern of LD between the HF and LF population confirmed their divergence in freezing tolerance. Furthermore, two Fst outlier methods; finite island model (fdist by LOSITAN and hierarchical structure model using ARLEQUIN detected six loci under directional selection. These outlier loci are most probably linked to genes involved in freezing tolerance, cold adaptation and abiotic stress and might be the potential marker resources for breeding perennial ryegrass cultivars with improved freezing tolerance.

  14. Delayed chlorophyll a fluorescence, MR 820, and gas exchange changes in perennial ryegrass under salt stress

    International Nuclear Information System (INIS)

    Dąbrowski, P.; Kalaji, M.H.; Baczewska, A.H.; Pawluśkiewicz, B.; Mastalerczuk, G.; Borawska-Jarmułowicz, B.; Paunov, M.; Goltsev, V.

    2017-01-01

    Perennial ryegrass (Lolium perenne L.) is one of the more popular grass species in Europe. It is commonly used for starting lawns in urban areas, where plant growth is limited by many environmental conditions. The contamination of soils by salt is one of the major problems in urban green areas, as well as in natural areas. The basic aim of this study is to provide a detailed in vivo analysis of the changes in the delayed chlorophyll fluorescence and MR 820 signals (induced by salt stress) of two lawn varieties of perennial ryegrass, and to find out if there are correlations between these parameters and gas exchange. Two lawn varieties of Lolium perenne L. were used: Nira and Roadrunner. Salinization was performed at 8 weeks after sowing by adding NaCl in water solution (0, 0.15, and 0.30 M). There were 8 terms of measurement: 0 h, 24 h, 48 h, 96 h, 144 h, 192 h, 240 h, and 288 h after salinization. Our results showed that delayed fluorescence is a tool that can bring completely new opportunities for detecting stress in plants caused by salt. Our work allowed us to identify various limitation patterns in the photosynthetic efficiency of perennial ryegrass lawn varieties grown under salt stress conditions. Significant differences between the two tested varieties in response to salt stress were confirmed.

  15. The transfer of radionuclides from contaminated groundwater into perennial ryegrass and winter wheat

    International Nuclear Information System (INIS)

    Wadey, P.; Shaw, G.; Butler, A. P.; Tompkins, J. A.; Wheater, H. S.

    1996-01-01

    Lysimeter studies of the migration of radionuclides from a contaminated water table and their subsequent uptake by plant roots have been undertaken using two distinct soil types and varying crop regimes. An eight year multi-disciplinary research project (funded by Nirex) has concentrated on the upward migration of contaminants from near-surface water tables, and their uptake by winter wheat and perennial ryegrass crops. Experimental data are presented for the movement and uptake of radiocaesium 137 Cs. These data show significant movement in the unsaturated zone during the first year of dosing, followed by progressively reduced availability in subsequent years. A suite of physically based hydrological and solute transport models has been developed to model radionuclide transport in the unsaturated zone. Model simulations, based on a conventional advection-dispersion representation incorporating linear sorption processes, were unable to describe adequately the distribution of radiocaesium within the soil profile. However, the introduction of root storage and translocation processes provided significantly improved results. (author)

  16. Sheep numbers required for dry matter digestibility evaluations when fed fresh perennial ryegrass or forage rape.

    Science.gov (United States)

    Sun, Xuezhao; Krijgsman, Linda; Waghorn, Garry C; Kjestrup, Holly; Koolaard, John; Pacheco, David

    2017-03-01

    Research trials with fresh forages often require accurate and precise measurement of digestibility and variation in digestion between individuals, and the duration of measurement periods needs to be established to ensure reliable data are obtained. The variation is likely to be greater when freshly harvested feeds are given, such as perennial ryegrass ( Lolium perenne L.) and forage rape ( Brassica napus L.), because the nutrient composition changes over time and in response to weather conditions. Daily feed intake and faeces output data from a digestibility trial with these forages were used to calculate the effects of differing lengths of the measurement period and differing numbers of sheep, on the precision of digestibility, with a view towards development of a protocol. Sixteen lambs aged 8 months and weighing 33 kg at the commencement of the trial were fed either perennial ryegrass or forage rape (8/treatment group) over 2 periods with 35 d between measurements. They had been acclimatised to the diets, having grazed them for 42 d prior to 11 days of indoor measurements. The sheep numbers required for a digestibility trial with different combinations of acclimatisation and measurement period lengths were subsequently calculated for 3 levels of imposed precision upon the estimate of mean dry matter (DM) digestibility. It is recommended that if the standard error of the mean for digestibility is equal to or higher than 5 g/kg DM, and if sheep are already used to a fresh perennial ryegrass or forage rape diet, then a minimum of 6 animals are needed and 4 acclimatisation days being fed individually in metabolic crates followed by 7 days of measurement.

  17. Photoperiodic regulation of flowering in perennial ryegrass involving a CONSTANS-like homolog

    DEFF Research Database (Denmark)

    Martin, J.; Storgaard, M.; Andersen, C.H.

    2004-01-01

    Photoperiod and vernalization are the two key environmental factors of the. oral induction of perennial ryegrass (Lolium perenne L.). Transition from vegetative to reproductive growth will only occur after an extended vernalization period, followed by an increase in day length and temperature. Here...... we report on the isolation and characterization of a L. perenne gene (LpCO) that is homologous to CONSTANS, and which is tightly coupled to the. oral inductive long day signal. Like other monocot CO-like proteins, the LpCO contains a zinc finger domain with a non-conserved B-Box2. Although the B-Box2...

  18. Induction of salicylic acid-mediated defense response in perennial ryegrass against infection by Magnaporthe oryzae.

    Science.gov (United States)

    Rahman, Alamgir; Kuldau, Gretchen A; Uddin, Wakar

    2014-06-01

    Incorporation of plant defense activators is an innovative approach to development of an integrated strategy for the management of turfgrass diseases. The effects of salicylic acid (SA), benzothiadiazole (BTH, chemical analog of SA), jasmonic acid (JA), and ethephon (ET, an ethylene-releasing compound) on development of gray leaf spot in perennial ryegrass (Lolium perenne L.) caused by Magnaporthe oryzae were evaluated. Gray leaf spot disease incidence and severity were significantly decreased when plants were treated prior to inoculation with SA, BTH, and partially by ET but not by JA. Accumulation of endogenous SA and elevated expression of pathogenesis-related (PR)-1, PR-3.1, and PR-5 genes were associated with inoculation of plants by M. oryzae. Treatment of plants with SA enhanced expression levels of PR-3.1 and PR-5 but did not affect the PR-1 level, whereas BTH treatment enhanced relative expression levels of all three PR genes. Microscopic observations of leaves inoculated with M. oryzae revealed higher frequencies of callose deposition at the penetration sites in SA- and BTH-treated plants compared with the control plants (treated with water). These results suggest that early and higher induction of these genes by systemic resistance inducers may provide perennial ryegrass with a substantial advantage to defend against infection by M. oryzae.

  19. Fructan metabolism and changes in fructan composition during cold acclimation in perennial ryegrass

    Science.gov (United States)

    Abeynayake, Shamila W.; Etzerodt, Thomas P.; Jonavičienė, Kristina; Byrne, Stephen; Asp, Torben; Boelt, Birte

    2015-01-01

    Perennial ryegrass (Lolium perenne L.) produces high levels of fructans as a mixture of oligosaccharides and polysaccharides with different degrees of polymerization (DP). The present study describes the analysis of the compositional changes in the full spectrum of fructans, fructan distribution between above ground biomass (top) and the roots, and the transcription of candidate genes involved in fructan metabolism during cold acclimation in perennial ryegrass variety “Veyo” and ecotype “Falster” from distinct geographical origins. We observed changes in fructan composition and induction of low-DP fructans, especially DP = 4, in both the top and the roots of “Veyo” and “Falster” in response to low-temperature stress. The accumulation of DP > 50 fructans was only apparent in the top tissues where the Lp1-FFT expression is higher compared to the roots in both “Veyo” and “Falster.” Our results also show the accumulation and depolymerization of fructans with different DP, together with the induction of genes encoding fructosyltransferases and fructan exohydrolases in both “Veyo” and “Falster” during cold acclimation, supporting the hypothesis that fructan synthesis and depolymerization occurring simultaneously. The ecotype “Falster,” adapted to cold climates, increased total fructan content and produced more DP > 7 fructans in the roots than the variety “Veyo,” adapted to warmer climates. This indicates that high-DP fructan accumulation in roots may be an adaptive trait for plant recovery after abiotic stresses. PMID:26029229

  20. Accuracy of Genomic Prediction in a Commercial Perennial Ryegrass Breeding Program

    Directory of Open Access Journals (Sweden)

    Dario Fè

    2016-11-01

    Full Text Available The implementation of genomic selection (GS in plant breeding, so far, has been mainly evaluated in crops farmed as homogeneous varieties, and the results have been generally positive. Fewer results are available for species, such as forage grasses, that are grown as heterogenous families (developed from multiparent crosses in which the control of the genetic variation is far more complex. Here we test the potential for implementing GS in the breeding of perennial ryegrass ( L. using empirical data from a commercial forage breeding program. Biparental F and multiparental synthetic (SYN families of diploid perennial ryegrass were genotyped using genotyping-by-sequencing, and phenotypes for five different traits were analyzed. Genotypes were expressed as family allele frequencies, and phenotypes were recorded as family means. Different models for genomic prediction were compared by using practically relevant cross-validation strategies. All traits showed a highly significant level of genetic variance, which could be traced using the genotyping assay. While there was significant genotype × environment (G × E interaction for some traits, accuracies were high among F families and between biparental F and multiparental SYN families. We have demonstrated that the implementation of GS in grass breeding is now possible and presents an opportunity to make significant gains for various traits.

  1. Biomonitoring of airborne mercury with perennial ryegrass cultures

    International Nuclear Information System (INIS)

    Temmerman, Ludwig de; Claeys, Natacha; Roekens, Edward; Guns, Marc

    2007-01-01

    A biomonitoring network with grass cultures was established near a chlor-alkali plant and the mercury concentration in the cultures were compared with the average atmospheric total gaseous mercury (TGM). Biomonitoring techniques based on different exposure periods were carried out. When comparing the mercury concentration in the grass cultures, both the average atmospheric TGM concentration during exposure and the exposure time determined to a large extent the accumulation rate of TGM. The maximum tolerable level of mercury in grass (≅110 μg kg -1 DM) corresponds with an average TGM concentration of 11 ng m -3 for 28 days exposure. The background concentrations in grass were on an average 15 μg kg -1 DM and the effect detection limit (EDL) was 30 μg kg -1 DM. This value corresponds with an average TGM concentration of 3.2 and 4.2 ng m -3 for 28 and 14 days exposure, respectively, which is in turn the biological detection limit (BDL) of ambient TGM. Exposures for 7 days were less appropriate for biomonitoring. - Grass accumulates TGM as a function of the atmospheric concentration and exposure time

  2. A 3-D Model of a Perennial Ryegrass Primary Cell Wall and Its Enzymatic Degradation

    Directory of Open Access Journals (Sweden)

    Indrakumar Vetharaniam

    2014-05-01

    Full Text Available We have developed a novel 3-D, agent-based model of cell-wall digestion to improve our understanding of ruminal cell-wall digestion. It offers a capability to study cell walls and their enzymatic modification, by providing a representation of cellulose microfibrils and non-cellulosic polysaccharides and by simulating their spatial and catalytic interactions with enzymes. One can vary cell-wall composition and the types and numbers of enzyme molecules, allowing the model to be applied to a range of systems where cell walls are degraded and to the modification of cell walls by endogenous enzymes. As a proof of principle, we have modelled the wall of a mesophyll cell from the leaf of perennial ryegrass and then simulated its enzymatic degradation. This is a primary, non-lignified cell wall and the model includes cellulose, hemicelluloses (glucuronoarabinoxylans, 1,3;1,4-β-glucans, and xyloglucans and pectin. These polymers are represented at the level of constituent monosaccharides, and assembled to form a 3-D, meso-scale representation of the molecular structure of the cell wall. The composition of the cell wall can be parameterised to represent different walls in different cell types and taxa. The model can contain arbitrary combinations of different enzymes. It simulates their random diffusion through the polymer networks taking collisions into account, allowing steric hindrance from cell-wall polymers to be modelled. Steric considerations are included when target bonds are encountered, and breakdown products resulting from enzymatic activity are predicted.

  3. Genetic Gain and Inbreeding from Genomic Selection in a Simulated Commercial Breeding Program for Perennial Ryegrass

    Directory of Open Access Journals (Sweden)

    Zibei Lin

    2016-03-01

    Full Text Available Genomic selection (GS provides an attractive option for accelerating genetic gain in perennial ryegrass ( improvement given the long cycle times of most current breeding programs. The present study used simulation to investigate the level of genetic gain and inbreeding obtained from GS breeding strategies compared with traditional breeding strategies for key traits (persistency, yield, and flowering time. Base population genomes were simulated through random mating for 60,000 generations at an effective population size of 10,000. The degree of linkage disequilibrium (LD in the resulting population was compared with that obtained from empirical studies. Initial parental varieties were simulated to match diversity of current commercial cultivars. Genomic selection was designed to fit into a company breeding program at two selection points in the breeding cycle (spaced plants and miniplot. Genomic estimated breeding values (GEBVs for productivity traits were trained with phenotypes and genotypes from plots. Accuracy of GEBVs was 0.24 for persistency and 0.36 for yield for single plants, while for plots it was lower (0.17 and 0.19, respectively. Higher accuracy of GEBVs was obtained for flowering time (up to 0.7, partially as a result of the larger reference population size that was available from the clonal row stage. The availability of GEBVs permit a 4-yr reduction in cycle time, which led to at least a doubling and trebling genetic gain for persistency and yield, respectively, than the traditional program. However, a higher rate of inbreeding per cycle among varieties was also observed for the GS strategy.

  4. Genetic Gain and Inbreeding from Genomic Selection in a Simulated Commercial Breeding Program for Perennial Ryegrass.

    Science.gov (United States)

    Lin, Zibei; Cogan, Noel O I; Pembleton, Luke W; Spangenberg, German C; Forster, John W; Hayes, Ben J; Daetwyler, Hans D

    2016-03-01

    Genomic selection (GS) provides an attractive option for accelerating genetic gain in perennial ryegrass () improvement given the long cycle times of most current breeding programs. The present study used simulation to investigate the level of genetic gain and inbreeding obtained from GS breeding strategies compared with traditional breeding strategies for key traits (persistency, yield, and flowering time). Base population genomes were simulated through random mating for 60,000 generations at an effective population size of 10,000. The degree of linkage disequilibrium (LD) in the resulting population was compared with that obtained from empirical studies. Initial parental varieties were simulated to match diversity of current commercial cultivars. Genomic selection was designed to fit into a company breeding program at two selection points in the breeding cycle (spaced plants and miniplot). Genomic estimated breeding values (GEBVs) for productivity traits were trained with phenotypes and genotypes from plots. Accuracy of GEBVs was 0.24 for persistency and 0.36 for yield for single plants, while for plots it was lower (0.17 and 0.19, respectively). Higher accuracy of GEBVs was obtained for flowering time (up to 0.7), partially as a result of the larger reference population size that was available from the clonal row stage. The availability of GEBVs permit a 4-yr reduction in cycle time, which led to at least a doubling and trebling genetic gain for persistency and yield, respectively, than the traditional program. However, a higher rate of inbreeding per cycle among varieties was also observed for the GS strategy. Copyright © 2016 Crop Science Society of America.

  5. A comparative study of molecular and morphological methods of describing relationships between perennial ryegrass (Lolium perenne L.) varieties

    NARCIS (Netherlands)

    Roldán-Ruiz, I.; Eeuwijk, van F.A.; Gilliland, T.J.; Dubreuil, P.; Dillmann, C.; Lallemand, J.; Loose, De M.; Baril, C.P.

    2001-01-01

    A sample set of registered perennial ryegrass varieties was used to compare how morphological characterisation and AFLP® (AFLP® is a registered trademark of Keygene N.V.) and STS molecular markers described variety relationships. All the varieties were confirmed as morphologically distinct, and both

  6. Exogenous Classic Phytohormones Have Limited Regulatory Effects on Fructan and Primary Carbohydrate Metabolism in Perennial Ryegrass (Lolium perenne L.)

    Czech Academy of Sciences Publication Activity Database

    Gasperl, A.; Morvan-Bertrand, A.; Prud'homme, M. P.; van der Graaff, E.; Roitsch, Thomas

    2016-01-01

    Roč. 6, jan (2016), s. 1251 ISSN 1664-462X R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : enzymatic activity * fructan exohydrolase * fructan metabolism * fructosyltransferase * perennial ryegrass * phytohormones * primary carbohydrate metabolism Subject RIV: ED - Physiology Impact factor: 4.298, year: 2016

  7. Inheritance patterns of the response to in vitro doubled haploid induction in perennial ryegrass (Lolium perenne L.)

    Czech Academy of Sciences Publication Activity Database

    Begheyn, R. F.; Roulund, N.; Vangsgaard, K.; Kopecký, David; Studer, B.

    2017-01-01

    Roč. 130, č. 3 (2017), s. 667-679 ISSN 0167-6857 Institutional support: RVO:61389030 Keywords : Androgenesis * Androgenic capacity * Anther culture * Doubled haploid (DH) * Perennial ryegrass (Lolium perenne L.) Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 2.002, year: 2016

  8. A Simple and Fast Kinetic Assay for the Determination of Fructan Exohydrolase Activity in Perennial Ryegrass (Lolium perenne L.)

    Czech Academy of Sciences Publication Activity Database

    Gasperl, A.; Morvan-Bertrand, A.; Prud'homme, M. P.; van der Graaff, E.; Roitsch, Thomas

    2015-01-01

    Roč. 6, dec (2015), s. 1154 ISSN 1664-462X R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : 1-FEH * enzymaticactivity * fructanexohydrolase * fructandegradation * kinetic assay * perennial ryegrass Subject RIV: EH - Ecology, Behaviour Impact factor: 4.495, year: 2015

  9. Expressed sequence tag-derived microsatellite markers of perennial ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Studer, Bruno; Asp, Torben; Frei, Ursula

    2008-01-01

    An expressed sequence tag (EST) library of the key grassland species perennial ryegrass (Lolium perenne L.) has been exploited as a resource for microsatellite marker development. Out of 955 simple sequence repeat (SSR) containing ESTs, 744 were used for primer design. Primer amplification was te...

  10. Genomic Selection Using Genotyping-By-Sequencing Data with Different Coverage Depth in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Cericola, Fabio; Fé, Dario; Janss, Luc

    2015-01-01

    the diagonal elements by estimating the amount of genetic variance caused by the reduction of the coverage depth. Secondly we developed a method to scale the relationship matrix by taking into account the overall amount of pairwise non-missing loci between all families. Rust resistance and heading date were......Genotyping by sequencing (GBS) allows generating up to millions of molecular markers with a cost per sample which is proportional to the level of multiplexing. Increasing the sample multiplexing decreases the genotyping price but also reduces the numbers of reads per marker. In this work we...... investigated how this reduction of the coverage depth affects the genomic relationship matrices used to estimated breeding value of F2 family pools in perennial ryegrass. A total of 995 families were genotyped via GBS providing more than 1.8M allele frequency estimates for each family with an average coverage...

  11. Seasonal Variation of Provitamin D2 and Vitamin D2 in Perennial Ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Jäpelt, Rie Bak; Didion, Thomas; Smedsgaard, Jørn

    2011-01-01

    Ergosterol (provitamin D(2)) is converted to vitamin D(2) in grass by exposure to UV light. Six varieties of perennial ryegrass (Lolium perenne L.) were harvested four times during the season, and the contents of vitamin D(2) and ergosterol were analyzed by a sensitive and selective liquid...... chromatography tandem mass spectrometry method. Weather factors were recorded, and a principal component analysis was performed to study which factors were important for the formation of vitamin D(2). The results suggest that a combination of weather factors is involved and that the contents of ergosterol...... and vitamin D(2) change more than a factor of 10 during the season. These results demonstrate that grass potentially can be a significant source of vitamin D for grazing animals and animals fed on silage and hay....

  12. Predicting seed yield in perennial ryegrass using repeated canopy reflectance measurements and PLSR

    DEFF Research Database (Denmark)

    Gislum, René; Deleuran, Lise Christina; Boelt, Birte

    2009-01-01

    with first year seed crops using three sowing rates and three spring nitrogen (N) application rates. PLSR models were developed for each year and showed correlation coefficients of 0.71, 0.76, and 0.92, respectively. Regression coefficients showed in these experiments that the optimum time for canopy...... reflectance measurements was from approximately 600 cumulative growing degree-days (CGDD) to approximately 900 CGDD. This is the period just before and at heading of the seed crop. Furthermore, regression coefficients showed that information about N and water is important. The results support the development......Repeated canopy reflectance measurements together with partial least-squares regression (PLSR) were used to predict seed yield in perennial ryegrass (Lolium perenne L.). The measurements were performed during the spring and summer growing seasons of 2001 to 2003 in three field experiments...

  13. Physiological Mechanism of Enhancing Salt Stress Tolerance of Perennial Ryegrass by 24-Epibrassinolide

    Directory of Open Access Journals (Sweden)

    Wenli Wu

    2017-06-01

    Full Text Available Brassinosteroids (BR regulate plant tolerance to salt stress but the mechanisms underlying are not fully understood. This study was to investigate physiological mechanisms of 24-epibrassinolide (EBR's impact on salt stress tolerance in perennial ryegrass (Lolium perenne L. The grass seedlings were treated with EBR at 0, 10, and 100 nM, and subjected to salt stress (250 mM NaCl. The grass irrigated with regular water without EBR served as the control. Salt stress increased leaf electrolyte leakage (EL, malondialdehyde (MDA, and reduced photosynthetic rate (Pn. Exogenous EBR reduced EL and MDA, increased Pn, chlorophyll content, and stomatal conductance (gs. The EBR applications also alleviated decline of superoxide dismutase (SOD and catalase (CAT and ascorbate peroxidase (APX activity when compared to salt treatment alone. Salt stress increased leaf abscisic acid (ABA and gibberellin A4 (GA4 content but reduced indole-3-acetic acid (IAA, zeatin riboside (ZR, isopentenyl adenosine (iPA, and salicylic acid (SA. Exogenous EBR at 10 nm and 100 nM increased ABA, and iPA content under salt stress. The EBR treatment at 100 nM also increased leaf IAA, ZR, JA, and SA. In addition, EBR treatments increased leaf proline and ions (K+, Mg2+, and Ca2+ content, and reduced Na+/K+ in leaf tissues. The results of this study suggest that EBR treatment may improve salt stress tolerance by increasing the level of selected hormones and antioxidant enzyme (SOD and CAT activity, promoting accumulation of proline and ions (K+, Ca2+, and Mg2+ in perennial ryegrass.

  14. B chromosomes are associated with redistribution of genetic recombination towards lower recombination chromosomal regions in perennial ryegrass.

    Science.gov (United States)

    Harper, John; Phillips, Dylan; Thomas, Ann; Gasior, Dagmara; Evans, Caron; Powell, Wayne; King, Julie; King, Ian; Jenkins, Glyn; Armstead, Ian

    2018-04-09

    Supernumerary 'B' chromosomes are non-essential components of the genome present in a range of plant and animal species-including many grasses. Within diploid and polyploid ryegrass and fescue species, including the forage grass perennial ryegrass (Lolium perenne L.), the presence of B chromosomes has been reported as influencing both chromosome pairing and chiasma frequencies. In this study, the effects of the presence/absence of B chromosomes on genetic recombination has been investigated through generating DArT (Diversity Arrays Technology) marker genetic maps for six perennial ryegrass diploid populations, the pollen parents of which contained either two B or zero B chromosomes. Through genetic and cytological analyses of these progeny and their parents, we have identified that, while overall cytological estimates of chiasma frequencies were significantly lower in pollen mother cells with two B chromosomes as compared with zero B chromosomes, the recombination frequencies within some marker intervals were actually increased, particularly for marker intervals in lower recombination regions of chromosomes, namely pericentromeric regions. Thus, in perennial ryegrass, the presence of two B chromosomes redistributed patterns of meiotic recombination in pollen mother cells in ways which could increase the range of allelic variation available to plant breeders.

  15. Temporal metagenomic and metabolomic characterisation of fresh perennial ryegrass degradation by rumen bacteria

    Directory of Open Access Journals (Sweden)

    Olga Mayorga

    2016-11-01

    Full Text Available Understanding the relationship between ingested plant material and the attached microbiome is essential for developing methodologies to improve ruminant nutrient use efficiency. We have previously shown that perennial ryegrass (PRG rumen bacterial colonisation events follow a primary (up to 4 h and secondary (after 4 h pattern based on the differences in diversity of the attached bacteria. In this study we investigated temporal niche specialisation of primary and secondary populations of attached rumen microbiota using metagenomic shotgun sequencing as well as monitoring changes in the plant chemistry using mid-infrared spectroscopy (FT-IR. Metagenomic Rapid Annotation using Subsystem Technology (MG-RAST taxonomical analysis of shotgun metagenomic sequences showed that the genera Butyrivibrio, Clostridium, Eubacterium, Prevotella and Selenomonas dominated the attached microbiome irrespective of time. MG-RAST also showed that Acidaminococcus, Bacillus, Butyrivibrio and Prevotella rDNA increased in read abundance during secondary colonisation, whilst Blautia decreased in read abundance. MG-RAST Clusters of Orthologous Groups (COG functional analysis also showed that the primary function of the attached microbiome was categorised broadly within ‘metabolism’; predominantly amino acid, carbohydrate, and lipid metabolism and transport. Most sequence read abundances (51.6, 43.8, and 50.0% of COG families pertaining to amino acid, carbohydrate and lipid metabolism, respectively within these categories were higher in abundance during secondary colonisation. Kyoto encyclopedia of genes and genomes (KEGG pathways analysis confirmed that the PRG- attached microbiota present at 1 and 4 h of rumen incubation possess a similar functional capacity, with only a few pathways being uniquely found in only one incubation time point only. FT-IR data for the plant residues also showed that the main changes in plant chemistry between primary and secondary

  16. Variation in the expression of ergot alkaloids between individual tillers of perennial ryegrass

    Science.gov (United States)

    Mace, Wade; Lunn, Kristy; Lloyd-West, Catherine

    2014-11-01

    Epichloë fungal endophytes of cool season grasses are well known to produce a range of alkaloids of benefit to the host. Some of these compounds are advantageous to agriculture due to qualities that promote pasture persistence (e.g. the loline class of alkaloids confer insect protection) while others are detrimental to the wellbeing of grazing livestock. The ergot alkaloids (e.g. ergovaline), produced in ryegrass and tall fescue associations, causes poor animal health in farming regions in many countries around the world and further study is required to improve our knowledge on this class of compounds. Here we present the application of a quantitative LC-MS/MS (liquid chromatography coupled to mass spectrometry) method measuring eight ergot alkaloids (chanoclavine, agroclavine, elymoclavine, lysergol, lysergic acid, ergine, lysergyl alanine, ergovaline) produced by endophyte infected grasses, to monitor levels in individual tillers from multiple plants of a single cultivar of perennial ryegrass (Lolium perenne cv. ‘Grasslands Samson’) infected with a common toxic endophyte strain (Epichloë festucae var. lolii). Monitoring the expression in individual tillers allows an estimation of the variability within a plant (between tillers) as well as between plants. The study showed that there is significant variation in the concentration of the ergot alkaloids between tillers of a single plant, at or exceeding the level of variation observed between individual plants of a population. This result emphasizes the fundamental importance of robust experimental design and sampling procedures when alkaloid expression assessment is required and these need to be rigorously tailored to the hypothesis being tested.

  17. Variation in the expression of ergot alkaloids between individual tillers of perennial ryegrass

    Directory of Open Access Journals (Sweden)

    Wade Jeffray Mace

    2014-11-01

    Full Text Available Epichloë fungal endophytes of cool season grasses are well known to produce a range of alkaloids of benefit to the host. Some of these compounds are advantageous to agriculture due to qualities that promote pasture persistence (e.g. the loline class of alkaloids confer insect protection while others are detrimental to the wellbeing of grazing livestock. The ergot alkaloids (e.g. ergovaline, produced in ryegrass and tall fescue associations, causes poor animal health in farming regions in many countries around the world and further study is required to improve our knowledge on this class of compounds. Here we present the application of a quantitative LC-MS/MS (liquid chromatography coupled to mass spectrometry method measuring eight ergot alkaloids (chanoclavine, agroclavine, elymoclavine, lysergol, lysergic acid, ergine, lysergyl alanine, ergovaline produced by endophyte infected grasses, to monitor levels in individual tillers from multiple plants of a single cultivar of perennial ryegrass (Lolium perenne cv. ‘Grasslands Samson’ infected with a common toxic endophyte strain (Epichloë festucae var. lolii. Monitoring the expression in individual tillers allows an estimation of the variability within a plant (between tillers as well as between plants.The study showed that there is significant variation in the concentration of the ergot alkaloids between tillers of a single plant, at or exceeding the level of variation observed between individual plants of a population. This result emphasizes the fundamental importance of robust experimental design and sampling procedures when alkaloid expression assessment is required and these need to be rigorously tailored to the hypothesis being tested.

  18. Analysis of DNA methylation of perennial ryegrass under drought using the methylation-sensitive amplification polymorphism (MSAP) technique.

    Science.gov (United States)

    Tang, Xiao-Mei; Tao, Xiang; Wang, Yan; Ma, Dong-Wei; Li, Dan; Yang, Hong; Ma, Xin-Rong

    2014-12-01

    Perennial ryegrass (Lolium perenne), an excellent grass for forage and turf, is widespread in temperate regions. Drought is an important factor that limits its growth, distribution, and yield. DNA methylation affects gene expression and plays an important role in adaptation to adverse environments. In this study, the DNA methylation changes in perennial ryegrass under drought stress were assessed using methylation-sensitive amplified polymorphism (MSAP). After 15 days of drought stress treatment, the plant height was less than half of the control, and the leaves were smaller and darker. Genome-wide, a total of 652 CCGG sites were detected by MSAP. The total methylation level was 57.67 and 47.39 % in the control and drought treatment, respectively, indicating a decrease of 10.28 % due to drought exposure. Fifteen differentially displayed DNA fragments in MSAP profiles were cloned for sequencing analysis. The results showed that most of the genes involved in stress responses. The relative expression levels revealed that three demethylated fragments were up-regulated. The expression of a predicted retrotransposon increased significantly, changing from hypermethylation to non-methylation. Although the extent of methylation in two other genes decreased, the sites of methylation remained, and the expression increased only slightly. All of these results suggested that drought stress decreased the total DNA methylation level in perennial ryegrass and demethylation up-regulated related gene expressions and that the extent of methylation was negatively correlated with expression. Overall, the induced epigenetic changes in genome probably are an important regulatory mechanism for acclimating perennial ryegrass to drought and possibly other environmental stresses.

  19. Complete chloroplast genome sequence of a major allogamous forage species, perennial ryegrass (Lolium perenne L.).

    Science.gov (United States)

    Diekmann, Kerstin; Hodkinson, Trevor R; Wolfe, Kenneth H; van den Bekerom, Rob; Dix, Philip J; Barth, Susanne

    2009-06-01

    Lolium perenne L. (perennial ryegrass) is globally one of the most important forage and grassland crops. We sequenced the chloroplast (cp) genome of Lolium perenne cultivar Cashel. The L. perenne cp genome is 135 282 bp with a typical quadripartite structure. It contains genes for 76 unique proteins, 30 tRNAs and four rRNAs. As in other grasses, the genes accD, ycf1 and ycf2 are absent. The genome is of average size within its subfamily Pooideae and of medium size within the Poaceae. Genome size differences are mainly due to length variations in non-coding regions. However, considerable length differences of 1-27 codons in comparison of L. perenne to other Poaceae and 1-68 codons among all Poaceae were also detected. Within the cp genome of this outcrossing cultivar, 10 insertion/deletion polymorphisms and 40 single nucleotide polymorphisms were detected. Two of the polymorphisms involve tiny inversions within hairpin structures. By comparing the genome sequence with RT-PCR products of transcripts for 33 genes, 31 mRNA editing sites were identified, five of them unique to Lolium. The cp genome sequence of L. perenne is available under Accession number AM777385 at the European Molecular Biology Laboratory, National Center for Biotechnology Information and DNA DataBank of Japan.

  20. Dynamics of initial colonization of nonconserved perennial ryegrass by anaerobic fungi in the bovine rumen.

    Science.gov (United States)

    Edwards, Joan E; Kingston-Smith, Alison H; Jimenez, Hugo R; Huws, Sharon A; Skøt, Kirsten P; Griffith, Gareth W; McEwan, Neil R; Theodorou, Michael K

    2008-12-01

    Anaerobic fungi (Neocallimastigales) are active degraders of fibrous plant material in the rumen. However, only limited information is available relating to how quickly they colonize ingested feed particles. The aim of this study was to determine the dynamics of initial colonization of forage by anaerobic fungi in the rumen and the impact of different postsampling wash procedures used to remove loosely associated microorganisms. Neocallimastigales-specific molecular techniques were optimized to ensure maximal coverage before application to assess the population size (quantitative PCR) and composition (automated ribosomal intergenic spacer analysis) of the colonizing anaerobic fungi. Colonization of perennial ryegrass (PRG) was evident within 5 min, with no consistent effect of time or wash procedure on fungal population composition. Wash procedure had no effect on population size unlike time, which had a significant effect. Colonizing fungal population size continued to increase over the incubation period after an initial lag of c. 4 min. This dynamic differs from that reported previously for rumen bacteria, where substantial colonization of PRG occurred within 5 min. The observed delay in colonization of plant material by anaerobic fungi is suggested to be primarily mediated by the time taken for fungal zoospores to locate, attach and encyst on plant material.

  1. Lambs Fed Fresh Winter Forage Rape (Brassica napus L.) Emit Less Methane than Those Fed Perennial Ryegrass (Lolium perenne L.), and Possible Mechanisms behind the Difference

    Science.gov (United States)

    Sun, Xuezhao; Henderson, Gemma; Cox, Faith; Molano, German; Harrison, Scott J.; Luo, Dongwen; Janssen, Peter H.; Pacheco, David

    2015-01-01

    The objectives of this study were to examine long-term effects of feeding forage rape (Brassica napus L.) on methane yields (g methane per kg of feed dry matter intake), and to propose mechanisms that may be responsible for lower emissions from lambs fed forage rape compared to perennial ryegrass (Lolium perenne L.). The lambs were fed fresh winter forage rape or ryegrass as their sole diet for 15 weeks. Methane yields were measured using open circuit respiration chambers, and were 22-30% smaller from forage rape than from ryegrass (averages of 13.6 g versus 19.5 g after 7 weeks, and 17.8 g versus 22.9 g after 15 weeks). The difference therefore persisted consistently for at least 3 months. The smaller methane yields from forage rape were not related to nitrate or sulfate in the feed, which might act as alternative electron acceptors, or to the levels of the potential inhibitors glucosinolates and S-methyl L-cysteine sulfoxide. Ruminal microbial communities in forage rape-fed lambs were different from those in ryegrass-fed lambs, with greater proportions of potentially propionate-forming bacteria, and were consistent with less hydrogen and hence less methane being produced during fermentation. The molar proportions of ruminal acetate were smaller and those of propionate were greater in forage rape-fed lambs, consistent with the larger propionate-forming populations and less hydrogen production. Forage rape contained more readily fermentable carbohydrates and less structural carbohydrates than ryegrass, and was more rapidly degraded in the rumen, which might favour this fermentation profile. The ruminal pH was lower in forage rape-fed lambs, which might inhibit methanogenic activity, shifting the rumen fermentation to more propionate and less hydrogen and methane. The significance of these two mechanisms remains to be investigated. The results suggest that forage rape is a potential methane mitigation tool in pastoral-based sheep production systems. PMID:25803688

  2. Life cycle inventory and risk assessment of genetic modified perennial ryegrass in a technology foresight perspective

    DEFF Research Database (Denmark)

    Borch, K.; Rasmussen, B.; Schleisner, L.

    2000-01-01

    important and uncertain fac-tors for the future direction of GM crops: 1) publicparticipation in regulation, 2) utility value for the consumers, 3) being first to market GM-ryegrass, and 4) an efficient professional network. Based on the identified drivers several scenar-ios were constructed, of which two......, a methodological approach is suggested to analyse the uncertainties that the biotech industry and the authorities face when implementing genetically modified (GM) crops. These uncertainties embracescientific rationality regarding technological development and risk assessments, as well as ethic political and social...

  3. Physiological effects of magnetite (Fe3O4) nanoparticles on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta) plants.

    Science.gov (United States)

    Wang, Huanhua; Kou, Xiaoming; Pei, Zhiguo; Xiao, John Q; Shan, Xiaoquan; Xing, Baoshan

    2011-03-01

    To date, knowledge gaps and associated uncertainties remain unaddressed on the effects of nanoparticles (NPs) on plants. This study was focused on revealing some of the physiological effects of magnetite (Fe(3)O(4)) NPs on perennial ryegrass (Lolium perenne L.) and pumpkin (Cucurbita mixta cv. white cushaw) plants under hydroponic conditions. This study for the first time reports that Fe(3)O(4) NPs often induced more oxidative stress than Fe(3)O(4) bulk particles in the ryegrass and pumpkin roots and shoots as indicated by significantly increased: (i) superoxide dismutase and catalase enzyme activities, and (ii) lipid peroxidation. However, tested Fe(3)O(4) NPs appear unable to be translocated in the ryegrass and pumpkin plants. This was supported by the following data: (i) No magnetization was detected in the shoots of either plant treated with 30, 100 and 500 mg l(-1) Fe(3)O(4) NPs; (ii) Fe K-edge X-ray absorption spectroscopic study confirmed that the coordination environment of Fe in these plant shoots was similar to that of Fe-citrate complexes, but not to that of Fe(3)O(4) NPs; and (iii) total Fe content in the ryegrass and pumpkin shoots treated with Fe(3)O(4) NPs was not significantly increased compared to that in the control shoots.

  4. Validation of reference genes for quantitative RT-PCR studies of gene expression in perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Thrush Anthony

    2010-01-01

    Full Text Available Abstract Background Perennial ryegrass (Lolium perenne L. is an important pasture and turf crop. Biotechniques such as gene expression studies are being employed to improve traits in this temperate grass. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR is among the best methods available for determining changes in gene expression. Before analysis of target gene expression, it is essential to select an appropriate normalisation strategy to control for non-specific variation between samples. Reference genes that have stable expression at different biological and physiological states can be effectively used for normalisation; however, their expression stability must be validated before use. Results Existing Serial Analysis of Gene Expression data were queried to identify six moderately expressed genes that had relatively stable gene expression throughout the year. These six candidate reference genes (eukaryotic elongation factor 1 alpha, eEF1A; TAT-binding protein homolog 1, TBP-1; eukaryotic translation initiation factor 4 alpha, eIF4A; YT521-B-like protein family protein, YT521-B; histone 3, H3; ubiquitin-conjugating enzyme, E2 were validated for qRT-PCR normalisation in 442 diverse perennial ryegrass (Lolium perenne L. samples sourced from field- and laboratory-grown plants under a wide range of experimental conditions. Eukaryotic EF1A is encoded by members of a multigene family exhibiting differential expression and necessitated the expression analysis of different eEF1A encoding genes; a highly expressed eEF1A (h, a moderately, but stably expressed eEF1A (s, and combined expression of multigene eEF1A (m. NormFinder identified eEF1A (s and YT521-B as the best combination of two genes for normalisation of gene expression data in perennial ryegrass following different defoliation management in the field. Conclusions This study is unique in the magnitude of samples tested with the inclusion of numerous field-grown samples

  5. Improved fructan accumulation in perennial ryegrass transformed with the onion fructosyltransferase genes 1-SST and 6G-FFT

    DEFF Research Database (Denmark)

    Gadegaard, Gitte; Didion, Thomas; Foiling, Marianne

    2008-01-01

    Carbohydrate limitation has been identified as a main cause of inefficient nitrogen use in ruminant animals, which feed mainly on fresh forage, hay and silage. This inefficiency results in suboptimal meat and milk productivity. One important molecular breeding strategy is to improve the nutritional...... value of ryegrass (Lolium perenne) by increasing the fructan content through expression of heterologous fructan biosynthetic genes. We developed perennial ryegrass Lines expressing sucrose:sucrose 1-fructosyltransferase and fructan:fructan 6G-fructosyltransferase genes from onion (Allium cepa) which...... exhibited up to a 3-fold increased fructan content. Further, the high fructan content was stable during the growth period, whereas the fructan content in an elite variety, marketed as a high sugar variety, dropped rapidly after reaching its maximum and subsequently remained low. (c) 2007 Elsevier GmbH. ALL...

  6. Genetic and Environmental Variance Among F2 Families in a Commercial Breeding Program for Perennial Ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Fé, Dario; Greve-Pedersen, Morten; Jensen, Christian Sig

    2013-01-01

    In the joint project “FORAGESELECT”, we aim to implement Genome Wide Selection (GWS) in breeding of perennial ryegrass (Lolium perenne L.), in order to increase genetic response in important agronomic traits such as yield, seed production, stress tolerance and disease resistance, while decreasing...... of this study was to estimate the genetic and environmental variance in the training set composed of F2 families selected from a ten year breeding period. Variance components were estimated on 1193 of those families, sown in 2001, 2003 and 2005 in five locations around Europe. Families were tested together...

  7. Interannual variation in nitrous oxide emissions from perennial ryegrass/white clover grassland used for dairy production.

    Science.gov (United States)

    Burchill, William; Li, Dejun; Lanigan, Gary J; Williams, Micheal; Humphreys, James

    2014-10-01

    Nitrous oxide (N2 O) emissions are subject to intra- and interannual variation due to changes in weather and management. This creates significant uncertainties when quantifying estimates of annual N2 O emissions from grazed grasslands. Despite these uncertainties, the majority of studies are short-term in nature (Nitrous oxide emissions were measured from fertilized and grazed perennial ryegrass/white clover grassland (WC) and from perennial ryegrass plots that were not grazed and did not receive N input (GB), over 4 years from 2008 to 2012 in Ireland (52°51'N, 08°21'W). The annual N2 O-N emissions (kg ha(-1); mean ± SE) ranged from 4.4 ± 0.2 to 34.4 ± 5.5 from WC and from 1.7 ± 0.8 to 6.3 ± 1.2 from GB. Interannual variation in N2 O emissions was attributed to differences in annual rainfall, monthly (December) soil temperatures and variation in N input. Such substantial interannual variation in N2 O emissions highlights the need for long-term studies of emissions from managed pastoral systems. © 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  8. A DArT marker genetic map of perennial ryegrass (Lolium perenne L.) integrated with detailed comparative mapping information; comparison with existing DArT marker genetic maps of Lolium perenne, L. multiflorum and Festuca pratensis.

    Science.gov (United States)

    King, Julie; Thomas, Ann; James, Caron; King, Ian; Armstead, Ian

    2013-07-03

    Ryegrasses and fescues (genera, Lolium and Festuca) are species of forage and turf grasses which are used widely in agricultural and amenity situations. They are classified within the sub-family Pooideae and so are closely related to Brachypodium distachyon, wheat, barley, rye and oats. Recently, a DArT array has been developed which can be used in generating marker and mapping information for ryegrasses and fescues. This represents a potential common marker set for ryegrass and fescue researchers which can be linked through to comparative genomic information for the grasses. A F2 perennial ryegrass genetic map was developed consisting of 7 linkage groups defined by 1316 markers and deriving a total map length of 683 cM. The marker set included 866 DArT and 315 gene sequence-based markers. Comparison with previous DArT mapping studies in perennial and Italian ryegrass (L. multiflorum) identified 87 and 105 DArT markers in common, respectively, of which 94% and 87% mapped to homoeologous linkage groups. A similar comparison with meadow fescue (F. pratensis) identified only 28 DArT markers in common, of which c. 50% mapped to non-homoelogous linkage groups. In L. perenne, the genetic distance spanned by the DArT markers encompassed the majority of the regions that could be described in terms of comparative genomic relationships with rice, Brachypodium distachyon, and Sorghum bicolor. DArT markers are likely to be a useful common marker resource for ryegrasses and fescues, though the success in aligning different populations through the mapping of common markers will be influenced by degrees of population interrelatedness. The detailed mapping of DArT and gene-based markers in this study potentially allows comparative relationships to be derived in future mapping populations characterised using solely DArT markers.

  9. Comparison of the fatty acid composition of fresh and ensiled perennial ryegrass (Lolium perenne L.), affected by cultivar and regrowth interval

    NARCIS (Netherlands)

    Elgersma, A.; Ellen, G.; Horst, van der H.; Muuse, B.G.; Boer, H.; Tamminga, S.

    2003-01-01

    Two experiments were conducted to evaluate the effects of grass cultivar and regrowth stage on the fatty acid (FA) profile in fresh and ensiled perennial ryegrass (Lolium perenne L.). The Experiment 1 compared the composition of fresh grass with that of pre-wilted ensiled material of six cultivars,

  10. Short-term effects of a dung pat on N2 fixation and total N uptake in a perennial ryegrass/white clover mixture

    DEFF Research Database (Denmark)

    Jørgensen, F.V.; Jensen, E.S.

    1997-01-01

    The short-term effects of a simulated cattle dung pat on N-2 fixation and total uptake of N in a perennial ryegrass/white clover mixture was studied in a container experiment using sheep faeces mixed with water to a DM content of 13%. We used a new N-15 cross-labelling technique to determine...

  11. A statistical mixture model for estimating the proportion of unreduced pollen grains in perennial ryegrass (Lolium perenne L.) via the size of pollen grains

    NARCIS (Netherlands)

    Jansen, R.C.; Nijs, A.P.M. den

    1993-01-01

    The size of pollen grains is commonly used to indicate the ploidy level of pollen grains. In this paper observations of the diameter of pollen grains are evaluated from one diploid accession of perennial ryegrass (Lolium perenne L.), which was expected to produce diploid (unreduced) pollen grains in

  12. Improving the quality of perennial ryegrass (Lolium perenne L.) for dairy cows by selecting for fast clearing and/or degradable neutral detergent fiber

    NARCIS (Netherlands)

    Taweel, H.Z.; Tas, B.M.; Smit, H.J.; Elgersma, A.; Dijkstra, J.; Tamminga, S.

    2005-01-01

    Neutral detergent fiber (NDF) fractional clearance rate (Kcl) and fractional degradation rate (kd) of six varieties of perennial ryegrass were measured to examine the possibility of selecting for varieties with fast degradable NDF. The experiment was conducted in 2000 and repeated in 2001. In each

  13. De novo assembly of the perennial ryegrass transcriptome using an RNA-seq strategy

    DEFF Research Database (Denmark)

    Farrell, Jacqueline Danielle; Byrne, Stephen; Paina, Cristiana

    2014-01-01

    a homozygous perennial ryegrass genotype can circumvent the challenge of heterozygosity. The goals of this study were to perform RNA-sequencing on multiple tissues from a highly inbred genotype to develop a reference transcriptome. This was complemented with RNA-sequencing of a highly heterozygous genotype...... for SNP calling. Result De novo transcriptome assembly of the inbred genotype created 185,833 transcripts with an average length of 830 base pairs. Within the inbred reference transcriptome 78,560 predicted open reading frames were found of which 24,434 were predicted as complete. Functional annotation...... multiple orthologs. Using the longest unique open reading frames as the reference sequence, 64,242 single nucleotide polymorphisms were found. One thousand sixty one open reading frames from the inbred genotype contained heterozygous sites, confirming the high degree of homozygosity. Conclusion Our study...

  14. Synergistic Effects of Bacillus amyloliquefaciens (GB03) and Water Retaining Agent on Drought Tolerance of Perennial Ryegrass.

    Science.gov (United States)

    Su, An-Yu; Niu, Shu-Qi; Liu, Yuan-Zheng; He, Ao-Lei; Zhao, Qi; Paré, Paul W; Li, Meng-Fei; Han, Qing-Qing; Ali Khan, Sardar; Zhang, Jin-Lin

    2017-12-11

    Water retaining agent (WRA) is widely used for soil erosion control and agricultural water saving. Here, we evaluated the effects of the combination of beneficial soil bacterium Bacillus amyloliquefaciens strain GB03 and WRA (the compound is super absorbent hydrogels) on drought tolerance of perennial ryegrass ( Lolium perenne L.). Seedlings were subjected to natural drought for maximum 20 days by stopping watering and then rewatered for seven days. Plant survival rate, biomass, photosynthesis, water status and leaf cell membrane integrity were measured. The results showed that under severe drought stress (20-day natural drought), compared to control, GB03, WRA and GB03+WRA all significantly improved shoot fresh weight, dry weight, relative water content (RWC) and chlorophyll content and decreased leaf relative electric conductivity (REC) and leaf malondialdehyde (MDA) content; GB03+WRA significantly enhanced chlorophyll content compared to control and other two treatments. Seven days after rewatering, GB03, WRA and GB03+WRA all significantly enhanced plant survival rate, biomass, RWC and maintained chlorophyll content compared to control; GB03+WRA significantly enhanced plant survival rate, biomass and chlorophyll content compared to control and other two treatments. The results established that GB03 together with water retaining agent promotes ryegrass growth under drought conditions by improving survival rate and maintaining chlorophyll content.

  15. Synergistic Effects of Bacillus amyloliquefaciens (GB03 and Water Retaining Agent on Drought Tolerance of Perennial Ryegrass

    Directory of Open Access Journals (Sweden)

    An-Yu Su

    2017-12-01

    Full Text Available Water retaining agent (WRA is widely used for soil erosion control and agricultural water saving. Here, we evaluated the effects of the combination of beneficial soil bacterium Bacillus amyloliquefaciens strain GB03 and WRA (the compound is super absorbent hydrogels on drought tolerance of perennial ryegrass (Lolium perenne L.. Seedlings were subjected to natural drought for maximum 20 days by stopping watering and then rewatered for seven days. Plant survival rate, biomass, photosynthesis, water status and leaf cell membrane integrity were measured. The results showed that under severe drought stress (20-day natural drought, compared to control, GB03, WRA and GB03+WRA all significantly improved shoot fresh weight, dry weight, relative water content (RWC and chlorophyll content and decreased leaf relative electric conductivity (REC and leaf malondialdehyde (MDA content; GB03+WRA significantly enhanced chlorophyll content compared to control and other two treatments. Seven days after rewatering, GB03, WRA and GB03+WRA all significantly enhanced plant survival rate, biomass, RWC and maintained chlorophyll content compared to control; GB03+WRA significantly enhanced plant survival rate, biomass and chlorophyll content compared to control and other two treatments. The results established that GB03 together with water retaining agent promotes ryegrass growth under drought conditions by improving survival rate and maintaining chlorophyll content.

  16. Validity of accessible critical nitrogen dilution curves in perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Gislum, René; Boelt, Birte

    2009-01-01

    The objectives were to test if accessible critical nitrogen dilution curves (NDCs) in rapeseed, pea, alfalfa, tall fescue, wheat, annual ryegrass and linseed could be used in grass species for seed production and to develop a critical NDC especially in grass species for seed production. The criti......The objectives were to test if accessible critical nitrogen dilution curves (NDCs) in rapeseed, pea, alfalfa, tall fescue, wheat, annual ryegrass and linseed could be used in grass species for seed production and to develop a critical NDC especially in grass species for seed production...... the NDCs in tall fescue, alfalfa, pea and rapeseed. These findings should be used to continue the interesting and necessary work on developing a NDC in grass species for seed production....

  17. Association of candidate genes with drought tolerance traits in diverse perennial ryegrass accessions

    Science.gov (United States)

    Xiaoqing Yu; Guihua Bai; Shuwei Liu; Na Luo; Ying Wang; Douglas S. Richmond; Paula M. Pijut; Scott A. Jackson; Jianming Yu; Yiwei. Jiang

    2013-01-01

    Drought is a major environmental stress limiting growth of perennial grasses in temperate regions. Plant drought tolerance is a complex trait that is controlled by multiple genes. Candidate gene association mapping provides a powerful tool for dissection of complex traits. Candidate gene association mapping of drought tolerance traits was conducted in 192 diverse...

  18. An arbuscular mycorrhizal fungus and Epichloë festucae var. lolii reduce Bipolaris sorokiniana disease incidence and improve perennial ryegrass growth.

    Science.gov (United States)

    Li, Fang; Guo, Yan'e; Christensen, Michael J; Gao, Ping; Li, Yanzhong; Duan, Tingyu

    2018-02-01

    Leaf spot of perennial ryegrass (Lolium perenne) caused by Bipolaris sorokiniana is an important disease in temperate regions of the world. We designed this experiment to test for the combined effects of the arbuscular mycorrhizal (AM) fungus Claroideoglomus etunicatum and the grass endophyte fungus Epichloë festucae var. lolii on growth and disease occurrence in perennial ryegrass. The results show that C. etunicatum increased plant P uptake and total dry weight and that this beneficial effect was slightly enhanced when in association with the grass endophyte. The presence in plants of both the endophyte and B. sorokiniana decreased AM fungal colonization. Plants inoculated with B. sorokiniana showed the typical leaf spot symptoms 2 weeks after inoculation and the lowest disease incidence was with plants that were host to both C. etunicatum and E. festucae var. lolii. Plants with these two fungi had much higher activity of peroxidases (POD), superoxide dismutase (SOD) and catalase (CAT) and lower values of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ). The AM fungus C. etunicatum and the grass endophyte fungus E. festucae var. lolii have the potential to promote perennial ryegrass growth and resistance to B. sorokiniana leaf spot.

  19. Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

    Science.gov (United States)

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

  20. Lead uptake from soils by perennial ryegrass and its relation to the supply of an essential element (sulfur)

    Energy Technology Data Exchange (ETDEWEB)

    Jones, L.H.P.; Jarvis, S.C.; Cowling, D.W.

    1973-06-01

    The lead status of 16 soils of England and Wales was studied by pot-culture and soil chemical procedures. Perennial ryegrass was grown on the soils, with and without added sulfur, in a controlled environment cabinet with carbon-filtered air. Plant-available lead comprised uptake in 4 successive harvests of tops plus that in roots at the final harvest. The concentration of lead in the tops of healthy plants, those with adequate sulfur, was lower than in the roots, e.g., at harvest 4 the means were 5.0 and 12.9 ppm, respectively. However, with sulfur-deficient plants the concentration of lead in the tops was often higher than in the roots, the means at harvest 4 being 16.3 and 13.0 ppm respectively. The marked increases in the concentration of lead in the tops of sulfur-deficient plants coincided with decreases in dry-matter yield, but for any one soil the tops of such plants contained similar amounts of lead to those of healthy plants. The led content of the tops was poorly correlated with soil lead whereas that of the roots, in terms of both concentration and total amount, was highly correlated. The amount of lead extracted by 0.5 M BaCl/sub 2/ or 0.05 M EDTA provided a slightly better assessment of availability than total content or the amount extracted by 2.5 percent acetic acid. The solutions of acetic acid, BaCl/sub 2/ and EDTA extracted, on average, 1.0, 16.3 and 32.7 per cent respectively of the total lead in the soils. The greater replacement of lead by the Ba ion than by the H ion (acetic acid) is ascribed to valence and the similar radii of Pb/sup 2 +/ and Ba/sup 2 +/. It is concluded that in soil-grown ryegrass the roots restrict the movement of lead into the tops of high-yielding plants, but when growth is limited by sulfur deficiency the concentration in the tops increases markedly.

  1. Effect of substituting fresh-cut perennial ryegrass with fresh-cut white clover on bovine milk fatty acid profile.

    Science.gov (United States)

    Stergiadis, Sokratis; Hynes, Deborah N; Thomson, Anna L; Kliem, Kirsty E; Berlitz, Carolina Gb; Günal, Mevlüt; Yan, Tianhai

    2018-03-06

    Including forage legumes in dairy systems can help address increasing environmental/economic concerns about perennial ryegrass monoculture pastures. This work investigated the effect of substituting fresh-cut grass with increasing quantities of fresh-cut white clover (WC) on milk fatty acid (FA) profile and transfer efficiency of dietary linoleic (LA) and α-linolenic (ALNA) acids to milk fat. Three groups of three crossbred dairy cows were used in a 3 × 3 crossover design. Dietary treatments were 0 g kg -1 WC + 600 g kg -1 grass, 200 g kg -1 WC + 400 g kg -1 grass, and 400 g kg -1 WC + 200 g kg -1 grass. All treatments were supplemented with 400 g kg -1 concentrates on a dry matter basis. Cows had a 19-day adaptation period to the experimental diet before a 6-day measurement period in individual tie stalls. Increasing dietary WC did not affect dry matter intake, milk yield or milk concentrations of fat, protein or lactose. Milk polyunsaturated FA concentrations (total n-3, total n-6, LA and ALNA) and transfer efficiency of LA and ALNA were increased with increasing dietary WC supply. Inclusion of WC in pastures may increase concentrations of nutritionally beneficial FA, without influencing milk yield and basic composition, but any implications on human health cannot be drawn. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

  2. Growth and Metal Accumulation of an Alyssum murale Nickel Hyperaccumulator Ecotype Co-cropped with Alyssum montanum and Perennial Ryegrass in Serpentine Soil

    Directory of Open Access Journals (Sweden)

    Catherine Leigh Broadhurst

    2016-04-01

    Full Text Available The genus Alyssum (Brassicaceae contains Ni hyperaccumulators (50, many of which can achieve 30 g kg-1 Ni in dry leaf. Some Alyssum hyperaccumulators are viable candidates for commercial Ni phytoremediation and phytomining technologies. It is not known whether these species secrete organic and/or amino acids into the rhizosphere to solubilize Ni, or can make use of such acids within the soil to facilitate uptake. It has been hypothesized that in fields with mixed plant species, mobilization of metals by phytosiderophores secreted by Graminaceae plants could affect Alyssum Ni, Fe, Cu and Mn uptake.We co-cropped the Ni hyperaccumulator Alyssum murale, non-hyperaccumulator A. montanum and perennial ryegrass in a natural serpentine soil. All treatments had standard inorganic fertilization required for ryegrass growth and one treatment was compost amended. After 4 months A. murale leaves and stems contained 3600 mg kg-1 Ni which did not differ significantly with co-cropping. Overall Ni and Mn concentrations were significantly higher in A. murale than in A. montanum or L. perenne. Copper was not accumulated by either Alyssum species, but L. perenne accumulated up to 10 mg kg-1. A. montanum could not compete with either A. murale or ryegrass, and neither Alyssum species survived in the compost-amended soil. Co-cropping with ryegrass reduced Fe and Mn concentrations in A. murale but not to the extent of either increasing Ni uptake or affecting plant nutrition. The hypothesized Alyssum Ni accumulation in response to phytosiderophores secreted by co-cropped grass did not occur. Our data do not support increased mobilization of Mn by a phytosiderophore mechanism either, but the converse: mobilization of Mn by the Alyssum hyperaccumulator species significantly increased Mn levels in L. perenne. Tilling soil to maximize root penetration, adequate inorganic fertilization and appropriate plant densities are more important for developing efficient

  3. Effect of pre-grazing herbage mass on dairy cow performance, grass dry matter production and output from perennial ryegrass (Lolium perenne L.) pastures.

    Science.gov (United States)

    Wims, C M; Delaby, L; Boland, T M; O'Donovan, M

    2014-01-01

    A grazing study was undertaken to examine the effect of maintaining three levels of pre-grazing herbage mass (HM) on dairy cow performance, grass dry matter (DM) production and output from perennial ryegrass (Lolium perenne L.) pastures. Cows were randomly assigned to one of three pre-grazing HM treatments: 1150 - Low HM (L), 1400 - Medium HM (M) or 2000 kg DM/ha - High HM (H). Herbage accumulation under grazing was lowest (Ppastures required more grass silage supplementation during the grazing season (+73 kg DM/cow) to overcome pasture deficits due to lower pasture growth rates (Ppasture intake, although cows grazing the L pastures had to graze a greater daily area (Ppasture reduces pasture DM production and at a system level may increase the requirement for imported feed.

  4. Structure-Function Analyses of a Caffeic Acid O-Methyltransferase from Perennial Ryegrass Reveal the Molecular Basis for Substrate Preference[W][OA

    Science.gov (United States)

    Louie, Gordon V.; Bowman, Marianne E.; Tu, Yi; Mouradov, Aidyn; Spangenberg, German; Noel, Joseph P.

    2010-01-01

    Lignin forms from the polymerization of phenylpropanoid-derived building blocks (the monolignols), whose modification through hydroxylation and O-methylation modulates the chemical and physical properties of the lignin polymer. The enzyme caffeic acid O-methyltransferase (COMT) is central to lignin biosynthesis. It is often targeted in attempts to engineer the lignin composition of transgenic plants for improved forage digestibility, pulping efficiency, or utility in biofuel production. Despite intensive investigation, the structural determinants of the regiospecificity and substrate selectivity of COMT remain poorly defined. Reported here are x-ray crystallographic structures of perennial ryegrass (Lolium perenne) COMT (Lp OMT1) in open conformational state, apo- and holoenzyme forms and, most significantly, in a closed conformational state complexed with the products S-adenosyl-l-homocysteine and sinapaldehyde. The product-bound complex reveals the post-methyl-transfer organization of COMT’s catalytic groups with reactant molecules and the fully formed phenolic-ligand binding site. The core scaffold of the phenolic ligand forges a hydrogen-bonding network involving the 4-hydroxy group that anchors the aromatic ring and thereby permits only metahydroxyl groups to be positioned for transmethylation. While distal from the site of transmethylation, the propanoid tail substituent governs the kinetic preference of ryegrass COMT for aldehydes over alcohols and acids due to a single hydrogen bond donor for the C9 oxygenated moiety dictating the preference for an aldehyde. PMID:21177481

  5. Structure-function analyses of a caffeic acid O-methyltransferase from perennial ryegrass reveal the molecular basis for substrate preference.

    Science.gov (United States)

    Louie, Gordon V; Bowman, Marianne E; Tu, Yi; Mouradov, Aidyn; Spangenberg, German; Noel, Joseph P

    2010-12-01

    Lignin forms from the polymerization of phenylpropanoid-derived building blocks (the monolignols), whose modification through hydroxylation and O-methylation modulates the chemical and physical properties of the lignin polymer. The enzyme caffeic acid O-methyltransferase (COMT) is central to lignin biosynthesis. It is often targeted in attempts to engineer the lignin composition of transgenic plants for improved forage digestibility, pulping efficiency, or utility in biofuel production. Despite intensive investigation, the structural determinants of the regiospecificity and substrate selectivity of COMT remain poorly defined. Reported here are x-ray crystallographic structures of perennial ryegrass (Lolium perenne) COMT (Lp OMT1) in open conformational state, apo- and holoenzyme forms and, most significantly, in a closed conformational state complexed with the products S-adenosyl-L-homocysteine and sinapaldehyde. The product-bound complex reveals the post-methyl-transfer organization of COMT's catalytic groups with reactant molecules and the fully formed phenolic-ligand binding site. The core scaffold of the phenolic ligand forges a hydrogen-bonding network involving the 4-hydroxy group that anchors the aromatic ring and thereby permits only metahydroxyl groups to be positioned for transmethylation. While distal from the site of transmethylation, the propanoid tail substituent governs the kinetic preference of ryegrass COMT for aldehydes over alcohols and acids due to a single hydrogen bond donor for the C9 oxygenated moiety dictating the preference for an aldehyde.

  6. Exploring the potential of phyllosilicate minerals as potassium fertilizers using sodium tetraphenylboron and intensive cropping with perennial ryegrass

    Science.gov (United States)

    Li, Ting; Wang, Huoyan; Wang, Jing; Zhou, Zijun; Zhou, Jianmin

    2015-01-01

    In response to addressing potassium (K) deficiency in soil and decreasing agricultural production costs, the potential of K-bearing phyllosilicate minerals that can be directly used as an alternative K source has been investigated using sodium tetraphenylboron (NaTPB) extraction and an intensive cropping experiment. The results showed that the critical value of K-release rate and leaf K concentration was 3.30 g kg−1 h−1 and 30.64 g (kg dry matter)−1, respectively under the experimental conditions. According to this critical value, the maximum amount of released K that could be utilized by a plant with no K deficiency symptoms was from biotite (27.80 g kg−1) and vermiculite (5.58 g kg−1), followed by illite, smectite and muscovite with 2.76, 0.88 and 0.49 g kg−1, respectively. Ryegrass grown on phlogopite showed K deficiency symptoms during the overall growth period. It is concluded that biotite and vermiculite can be directly applied as a promising and sustainable alternative to the use of classical K fertilizers, illite can be utilized in combination with soluble K fertilizers, whereas muscovite, phlogopite and smectite may not be suitable for plant growth. Further field experiments are needed to assess the use of these phyllosilicate minerals as sources of K fertilizer. PMID:25782771

  7. Immunological cross-reactivity of the major allergen from perennial ryegrass (Lolium perenne), Lol p I, and the cysteine proteinase, bromelain.

    Science.gov (United States)

    Pike, R N; Bagarozzi, D; Travis, J

    1997-04-01

    Antibodies prepared in rabbits against the major allergen from ryegrass (Lolium perenne), Lol p I, cross-reacted with the cysteine proteinase bromelain from pineapple and vice versa. Deglycosylation of the proteins showed that the cross-reaction was based on recognition of the carbohydrate moiety of the allergen, but for bromelain the cross-reaction was most likely due to a combination of factors. The results indicate that the carbohydrate residues from these allergens play an important role in cross-reactions found between them and possibly those from other species.

  8. Arbuscular mycorrhizal fungi enhance both absorption and stabilization of Cd by Alfred stonecrop (Sedum alfredii Hance) and perennial ryegrass (Lolium perenne L.) in a Cd-contaminated acidic soil.

    Science.gov (United States)

    Hu, Junli; Wu, Shengchun; Wu, Fuyong; Leung, Ho Man; Lin, Xiangui; Wong, Ming Hung

    2013-10-01

    A greenhouse pot experiment was conducted to compare the phytoextraction efficiencies of Cd by hyper-accumulating Alfred stonecrop (Sedum alfredii Hance) and fast-growing perennial ryegrass (Lolium perenne L.) from a Cd-contaminated (1.6 mg kg(-1)) acidic soil, and their responses to the inoculations of two arbuscular mycorrhizal (AM) fungal strains, Glomus caledonium 90036 (Gc) and Glomus mosseae M47V (Gm). Ryegrass and stonecrop were harvested after growing for 9 and 27 wk, respectively. Without AM fungal inoculation, the weekly Cd extraction by stonecrop (8.0 μg pot(-1)) was 4.3 times higher than that by ryegrass (1.5 μg pot(-1)). Both Gc and Gm significantly increased (P soil acid phosphatase activities, and available P concentrations, and thereby plant P absorptions (except for Gm-inoculated ryegrass), shoot biomasses, and Cd absorptions (except for Gm-inoculated stonecrop), while only Gc-inoculated stonecrop significantly accelerated (P soil pH. The results suggested the potential application of hyper-accumulating Alfred stonecrop associated with AM fungi (notably Gc) for both extraction and stabilization of Cd in the in situ treatment of Cd-contaminated acidic soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Acidification of pig slurry effects on ammonia and nitrous oxide emissions, nitrate leaching, and perennial ryegrass regrowth as estimated by N-urea flux

    Directory of Open Access Journals (Sweden)

    Sang Hyun Park

    2018-03-01

    Full Text Available Objective The present study aimed to assess the nitrogen (N use efficiency of acidified pig slurry for regrowth yield and its environmental impacts on perennial ryegrass swards. Methods The pH of digested pig slurry was adjusted to 5.0 or 7.0 by the addition of sulfuric acid and untreated as a control. The pig slurry urea of each treatment was labeled with 15N urea and applied at a rate of 200 kg N/ha immediately after cutting. Soil and herbage samples were collected at 7, 14, and 56 d of regrowth. The flux of pig slurry-N to regrowth yield and soil N mineralization were analyzed, and N losses via NH3, N2O emission and NO3− leaching were also estimated. Results The pH level of the applied slurry did not have a significant effect on herbage yield or N content of herbage at the end of regrowth, whereas the amount of N derived from pig slurry urea (NdfSU was higher in both herbage and soils in pH-controlled plots. The NH4+-N content and the amount of N derived from slurry urea into soil NH4+ fraction (NdfSU-NH4+ was significantly higher in in the pH 5 plot, whereas NO3− and NdfSU-NO3− were lower than in control plots over the entire regrowth period. Nitrification of NH4+-N was delayed in soil amended with acidified slurry. Compared to non-pH-controlled pig slurry (i.e. control plots, application of acidified slurry reduced NH3 emissions by 78.1%, N2O emissions by 78.9% and NO3− leaching by 17.81% over the course of the experiment. Conclusion Our results suggest that pig slurry acidification may represent an effective means of minimizing hazardous environmental impacts without depressing regrowth yield.

  10. A ¤Terminal Flower-1¤-like gene from perennial ryegrass involved in floral transition and axillary meristem identity

    DEFF Research Database (Denmark)

    Jensen, C.S.; Salchert, K.; Nielsen, K.K.

    2001-01-01

    12 weeks to induce flowering. During this period a decrease in LpTFL1 message was detected in the ryegrass apex. However, upon subsequent induction with elevated temperatures and long-day photoperiods, LpTFL1 message levels increased and reached a maximum M:hen the ryegrass apex has formed visible...

  11. Optimized Use of Low-Depth Genotyping-by-Sequencing for Genomic Prediction Among Multi-Parental Family Pools and Single Plants in Perennial Ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Fabio Cericola

    2018-03-01

    Full Text Available Ryegrass single plants, bi-parental family pools, and multi-parental family pools are often genotyped, based on allele-frequencies using genotyping-by-sequencing (GBS assays. GBS assays can be performed at low-coverage depth to reduce costs. However, reducing the coverage depth leads to a higher proportion of missing data, and leads to a reduction in accuracy when identifying the allele-frequency at each locus. As a consequence of the latter, genomic relationship matrices (GRMs will be biased. This bias in GRMs affects variance estimates and the accuracy of GBLUP for genomic prediction (GBLUP-GP. We derived equations that describe the bias from low-coverage sequencing as an effect of binomial sampling of sequence reads, and allowed for any ploidy level of the sample considered. This allowed us to combine individual and pool genotypes in one GRM, treating pool-genotypes as a polyploid genotype, equal to the total ploidy-level of the parents of the pool. Using simulated data, we verified the magnitude of the GRM bias at different coverage depths for three different kinds of ryegrass breeding material: individual genotypes from single plants, pool-genotypes from F2 families, and pool-genotypes from synthetic varieties. To better handle missing data, we also tested imputation procedures, which are suited for analyzing allele-frequency genomic data. The relative advantages of the bias-correction and the imputation of missing data were evaluated using real data. We examined a large dataset, including single plants, F2 families, and synthetic varieties genotyped in three GBS assays, each with a different coverage depth, and evaluated them for heading date, crown rust resistance, and seed yield. Cross validations were used to test the accuracy using GBLUP approaches, demonstrating the feasibility of predicting among different breeding material. Bias-corrected GRMs proved to increase predictive accuracies when compared with standard approaches to

  12. Identification of genes involved in a water stress response in timothy and mapping of orthologous loci in perennial ryegrass

    DEFF Research Database (Denmark)

    Jonavičienė, Kristina; Studer, Bruno; Asp, Torben

    2012-01-01

    In order to characterize the response of selected grasses to water stress, relative water content (RWC) in leaves and quantum efficiency of photosystem 2 (Fv/Fm) were measured in Phleum pratense L., P. bertolonii DC. and P. phleoides H. Karst. during 6 d of water stress. The results indicated...... differential responses to water stress among the three Phleum species with higher water deficit sensitivity of P. pratense and P. bertolonii than that of P. phleoides. The cDNA-amplified fragment length polymorphism (cDNA-AFLP) technique was applied to identify differentially expressed genes responding...... to water stress in P. pratense. Cloned and sequenced differentially expressed fragments (DEFs) were used for primer design in order to identify orthologous genes in Lolium perenne L. Twelve genes orthologous to P. pratense DEFs were mapped in the L. perenne mapping population VrnA based on a high...

  13. A simple and fast kinetic assay for the determination of fructan exohydrolase activity in perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Anna eGasperl

    2015-12-01

    Full Text Available Despite the fact that fructans are the main constituent of water-soluble carbohydrates in forage grasses and cereal crops of temperate climates, little knowledge is available on the regulation of the enzymes involved in fructan metabolism. The analysis of enzyme activities involved in this process has been hampered by the low affinity of the fructan enzymes for sucrose and fructans used as fructosyl donor. Further, the analysis of fructan composition and enzyme activities is restricted to specialized labs with access to suited HPLC equipment and appropriate fructan standards. The degradation of fructan polymers with high degree of polymerization (DP by fructan exohydrolases (FEHs to fructosyloligomers is important to liberate energy in the form of fructan, but also under conditions where the generation of low DP polymers is required. Based on published protocols employing enzyme coupled endpoint reactions in single cuvettes, we developed a simple and fast kinetic 1-FEH assay. This assay can be performed in multi-well plate format using plate readers to determine the activity of 1-FEH against 1-kestotriose, resulting in a significant time reduction. Kinetic assays allow an optimal and more precise determination of enzyme activities compared to endpoint assays, and enable to check the quality of any reaction with respect to linearity of the assay. The enzyme coupled kinetic 1-FEH assay was validated in a case study showing the expected increase in 1-FEH activity during cold treatment. This assay is cost effective and could be performed by any lab with access to a plate reader suited for kinetic measurements and readings at 340 nm, and is highly suited to assess temporal changes and relative differences in 1-FEH activities. Thus, this enzyme coupled kinetic 1-FEH assay is of high importance both to the field of basic fructan research and plant breeding.

  14. heat shock factor genes of tall fescue and perennial ryegrass in response to temperature stress by RNA-Seq analysis

    Directory of Open Access Journals (Sweden)

    Yan eWang

    2016-01-01

    Full Text Available Heat shock factors (Hsfs are important regulators of stress-response in plants. However, our understanding of Hsf genes and their responses to temperature stresses in two Pooideae cool-season grasses, Festuca arundinacea and Lolium perenne, is limited. Here we conducted comparative transcriptome analyses of plant leaves exposed to heat or cold stress for 10 h. Approximately, 30% and 25% of the genes expressed in the two species showed significant changes under heat and cold stress respectively, including subsets of Hsfs and their target genes. We uncovered 74 Hsfs in F. arundinacea and 52 Hsfs in L. perenne, and categorized these genes into three subfamilies, HsfA, HsfB, and HsfC based on protein sequence homology to known Hsf members in model organisms. The Hsfs showed a strong response to heat and/or cold stress. The expression of HsfAs was elevated under heat stress, especially in class HsfA2, which exhibited the most dramatic responses. HsfBs were upregulated by the both temperature conditions, and HsfCs mainly showed an increase in expression under cold stress. The target genes of Hsfs, such as heat shock protein (HSP, ascorbate peroxidase (APX, inositol-3-phosphate synthase (IPS, and galactinol synthase (GOLS1, showed strong and unique responses to different stressors. We comprehensively detected Hsfs and their target genes in F. arundinacea and L. perenne, providing a foundation for future gene function studies and genetic engineering to improve stress tolerance in grasses and other crops.

  15. Exogenous melatonin suppresses dark-induced leaf senescence by activating the superoxide dismutase-catalase antioxidant pathway and down-regulating chlorophyll degradation in excised leaves of perennial ryegrass (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2016-10-01

    Full Text Available Leaf senescence is a typical symptom in plants exposed to dark and may be regulated by plant growth regulators. The objective of this study was to determine whether exogenous application of melatonin (N-acetyl-5-methoxytryptamine suppresses dark-induced leaf senescence and the effects of melatonin on reactive oxygen species (ROS scavenging system and chlorophyll degradation pathway in perennial grass species. Mature perennial ryegrass (Lolium perenne L. cv. ‘Pinnacle’ leaves were excised and incubated in 3 mM 2-(N-morpholino ethanesulfonic buffer (pH 5.8 supplemented with melatonin or water (control and exposed to dark treatment for 8 d. Leaves treated with melatonin maintained significantly higher endogenous melatonin level, chlorophyll content, photochemical efficiency, and cell membrane stability expressed by lower electrolyte leakage and malondialdehyde (MDA content compared to the control. Exogenous melatonin treatment also reduced the transcript level of chlorophyll degradation-associated genes and senescence marker genes (LpSAG12.1, Lph36, and Lpl69 during the dark treatment. The endogenous O2- production rate and H2O2 content were significantly lower in these excised leaves treated with melatonin compared to the water control. Exogenous melatonin treatment caused increases in enzymatic activity and transcript levels of superoxide dismutase and catalase but had no significant effects on ascorbate peroxidase, glutathione reductase, dehydroascorbate reductase, and monohydroascorbate reductase. The content of non-enzymatic antioxidants, such as ascorbate and dehydroascorbate, were decreased by melatonin treatment, while the content of glutathione and oxidized glutathione was not affected by melatonin. These results suggest that the suppression of dark-induced leaf senescence by exogenous melatonin may be associated with its roles in regulating ROS scavenging through activating the superoxide dismutase-catalase enzymatic antioxidant

  16. Allelic Variation in the Perennial Ryegrass FLOWERING LOCUS T Gene is Associated with Changes in Flowering Time across a Range of Populations

    DEFF Research Database (Denmark)

    Skøt, Leif; Sanderson, Ruth; Thomas, Ann

    2011-01-01

    The Arabidopsis (Arabidopsis thaliana) FLOWERING LOCUS T (FT) gene and its orthologs in other plant species (e.g. rice [Oryza sativa] OsFTL2/Hd3a) have an established role in the photoperiodic induction of flowering response. The genomic and phenotypic variations associated with the perennial...

  17. Genomic Variance Estimation Based on Genotyping-by-Sequencing with Different Coverage in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Ashraf, Bilal; Fé, Dario; Jensen, Just

    2014-01-01

    at each SNP in family pools or polyploids. There are, however, several statistical challenges associated with this method, including low sequencing depth and missing values. Low sequencing depth results in inaccuracies in estimates of allele frequencies for each SNP. In this work we have focused...

  18. Bale Location Effects on Nutritive Value and Fermentation Characteristics of Annual Ryegrass Bale Stored in In-line Wrapping Silage

    Directory of Open Access Journals (Sweden)

    K. J. Han

    2014-09-01

    Full Text Available In southeastern regions of the US, herbage systems are primarily based on grazing or hay feeding with low nutritive value warm-season perennial grasses. Nutritious herbage such as annual ryegrass (Lolium multiflorum Lam. may be more suitable for preserving as baleage for winter feeding even with more intensive production inputs. Emerging in-line wrapped baleage storage systems featuring rapid wrapping and low polyethylene film requirements need to be tested for consistency of storing nutritive value of a range of annual ryegrass herbage. A ryegrass storage trial was conducted with 24-h wilted ‘Marshall’ annual ryegrass harvested at booting, heading and anthesis stages using three replicated in-line wrapped tubes containing ten round bales per tube. After a six-month storage period, nutritive value changes and fermentation end products differed significantly by harvest stage but not by bale location. Although wilted annual ryegrass exhibited a restricted fermentation across harvest stages characterized by high pH and low fermentation end product concentrations, butyric acid concentrations were less than 1 g/kg dry matter, and lactic acid was the major organic acid in the bales. Mold coverage and bale aroma did not differ substantially with harvest stage or bale location. Booting and heading stage-harvested ryegrass baleage were superior in nutritive value to anthesis stage-harvested herbage. Based on the investigated nutritive value and fermentation characteristics, individual bale location within in-line tubes did not significantly affect preservation quality of ryegrass round bale silages.

  19. Fatty acid oxidation products ('green odour') released from perennial ryegrass following biotic and abiotic stress, potentially have antimicrobial properties against the rumen microbiota resulting in decreased biohydrogenation.

    Science.gov (United States)

    Huws, S A; Scott, M B; Tweed, J K S; Lee, M R F

    2013-11-01

    In this experiment, we investigated the effect of 'green odour' products typical of those released from fresh forage postabiotic and biotic stresses on the rumen microbiota and lipid metabolism. Hydroperoxyoctadecatrienoic acid (HP), a combination of salicylic and jasmonic acid (T), and a combination of both (HPT) were incubated in vitro in the presence of freeze-dried ground silage and rumen fluid, under rumen-like conditions. 16S rRNA (16S cDNA) HaeIII-based terminal restriction fragment length polymorphism-based (T-RFLP) dendrograms, canonical analysis of principal coordinates graphs, peak number and Shanon-Weiner diversity indices show that HP, T and HPT likely had antimicrobial effects on the microbiota compared to control incubations. Following 6 h of in vitro incubation, 15.3% of 18:3n-3 and 4.4% of 18:2n-6 was biohydrogenated in control incubations, compared with 1.3, 9.4 and 8.3% of 18:3n-3 for HP, T and HPT treatments, respectively, with negligible 18:2n-6 biohydrogenation seen. T-RFLP peaks lost due to application of HP, T and HPT likely belonged to as yet uncultured bacteria within numerous genera. Hydroperoxyoctadecatrienoic acid, T and HPT released due to plant stress potentially have an antimicrobial effect on the rumen microbiota, which may explain the decreased biohydrogenation in vitro. These data suggest that these volatile chemicals may be responsible for the higher summer n-3 content of bovine milk. © 2013 The Society for Applied Microbiology.

  20. Modelling critical NDVI curves in perennial ryegrass

    DEFF Research Database (Denmark)

    Gislum, R; Boelt, B

    2010-01-01

      The use of optical sensors to measure canopy reflectance and calculate crop index as e.g. normalized difference vegetation index (NDVI) is widely used in agricultural crops, but has so far not been implemented in herbage seed production. The present study has the purpose to develop a critical...... NDVI curve where the critical NDVI, defined as the minimum NDVI obtained to achieve a high seed yield, will be modelled during the growing season. NDVI measurements were made at different growing degree days (GDD) in a three year field experiment where different N application rates were applied....... There was a clear maximum in the correlation coefficient between seed yield and NDVI in the period from approximately 700 to 900 GDD. At this time there was an exponential relationship between NDVI and seed yield where highest seed yield were at NDVI ~0.9. Theoretically the farmers should aim for an NDVI of 0...

  1. Herbage Production, Nutritive Value and Grazing Preference of Diploid and Tetraploid Perennial Ryegrass Cultivars (Lolium perenne L. Producción de Fitomasa, Calidad Nutritiva y Preferencia de Pastoreo de Cultivares Diploides y Tetraploides de Ballica Perenne (Lolium perenne L.

    Directory of Open Access Journals (Sweden)

    Oscar A Balocchi

    2009-09-01

    Full Text Available The objective of this study was to determine, under the soil and climatic conditions of Southern Chile, the effect of the ploidy of perennial ryegrass (Lolium perenne L. cultivars on herbage production, nutritive value, grazing preference and utilization of pasture produced. This study was conducted in southern Chile, Valdivia Province, and was evaluated for 3 years. The tetraploid cultivars used were Quartet (4n, Gwendal (4n, Pastoral (4n and Napoleon (4n. The diploid cultivars were Anita (2n, Jumbo (2n, Aries (2n, and Yatsyn 1 (2n.When the average sward height reached 20 cm, all plots were simultaneously grazed by dairy cows for a period of 24 h. Before and after grazing, sward height, dry matter availability and nutritive value were evaluated. Grazing preference was visually assessed every 5 min for a period of 2.5 h after the afternoon milking. During the 3-year period 20 grazing events were evaluated. A randomized complete block design, with eight cultivars and three replicates, was used. Diploid cultivars showed greater herbage mass accumulation than tetraploid cultivars (P ≤ 0.05. No significant differences were obtained in the annual average crude protein content. Nevertheless, tetraploid cultivars showed a greater D value than diploid cultivars, except during the third year when the difference was not statistically significant. Dairy cows grazed more time on tetraploid cultivars. Considering, additionally, the residual herbage mass after grazing and the percentage of pasture utilization, diploid cultivars were less intensively grazed, suggesting a lower consumption by the cows.El objetivo de este estudio fue determinar, bajo las condiciones edafoclimáticas del sur de Chile, el efecto de la ploidía de cultivares de ballica perenne (Lolium perenne L. sobre el rendimiento de fitomasa, calidad nutricional, preferencia de pastoreo y porcentaje de utilización del forraje producido. El ensayo se realizó en el sur de Chile, provincia de

  2. Comparison of herbage yield, nutritive value and ensilability traits of three ryegrass species evaluated for the Irish Recommended List

    Directory of Open Access Journals (Sweden)

    Burns G. A.

    2015-06-01

    Full Text Available This study examined 169 of the newest varieties of three ryegrass species, perennial (Lolium perenne L., Italian (Lolium multiflorum Lam. and hybrid (Lolium boucheanum Kunth, from Recommended List trials in Ireland. The traits examined were yield, dry matter concentration, three nutritive value traits (in vitro dry matter digestibility, water-soluble carbohydrate on a dry matter basis and crude protein concentration and two ensilability traits (buffering capacity and water soluble carbohydrate concentration on an aqueous phase basis. Varietal monocultures of each species underwent a six cut combined simulated grazing and silage management in each of two years following sowing. Perennial ryegrass yielded less than both other species in one-year-old swards, but less than only Italian ryegrass in two-year-old swards, but generally had the higher in vitro dry matter digestibility and crude protein values. Italian ryegrass displayed the most favourable ensilability characteristics of the three species with perennial ryegrass less favourable and hybrid ryegrass intermediate. Overall, despite the high yields and favourable nutritive value and ensilability traits recorded, the general differences between the three ryegrass species studied were in line with industry expectations. These findings justify assessing the nutritive value and ensilability of ryegrass species, in addition to yield, to allow farmers select species that match farming enterprise requirements.

  3. Impacts of endophyte infection of ryegrass on rhizosphere metabolome and microbial community

    DEFF Research Database (Denmark)

    Wakelin, S.; Harrison, Scott James; Mander, C.

    2015-01-01

    37, within a genetically uniform breeding line of perennial ryegrass (Lolium perenne cv. Samson 11104) on the rhizosphere metabolome and the composition of the fungal, bacterial, and Pseudomonas communities. There were strong differences in the rhizosphere metabolomes between infested and non......-infested ryegrass strains (P=0.06). These were attributed to shifts in various n-alkane hydrocarbon compounds. The endophyte-associated alteration in rhizosphere metabolome was linked to changes in the total bacterial (P

  4. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Science.gov (United States)

    Talukder, Shyamal K.; Saha, Malay C.

    2017-01-01

    Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS) are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs). Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder. PMID:28798766

  5. Toward Genomics-Based Breeding in C3 Cool-Season Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Shyamal K. Talukder

    2017-07-01

    Full Text Available Most important food and feed crops in the world belong to the C3 grass family. The future of food security is highly reliant on achieving genetic gains of those grasses. Conventional breeding methods have already reached a plateau for improving major crops. Genomics tools and resources have opened an avenue to explore genome-wide variability and make use of the variation for enhancing genetic gains in breeding programs. Major C3 annual cereal breeding programs are well equipped with genomic tools; however, genomic research of C3 cool-season perennial grasses is lagging behind. In this review, we discuss the currently available genomics tools and approaches useful for C3 cool-season perennial grass breeding. Along with a general review, we emphasize the discussion focusing on forage grasses that were considered orphan and have little or no genetic information available. Transcriptome sequencing and genotype-by-sequencing technology for genome-wide marker detection using next-generation sequencing (NGS are very promising as genomics tools. Most C3 cool-season perennial grass members have no prior genetic information; thus NGS technology will enhance collinear study with other C3 model grasses like Brachypodium and rice. Transcriptomics data can be used for identification of functional genes and molecular markers, i.e., polymorphism markers and simple sequence repeats (SSRs. Genome-wide association study with NGS-based markers will facilitate marker identification for marker-assisted selection. With limited genetic information, genomic selection holds great promise to breeders for attaining maximum genetic gain of the cool-season C3 perennial grasses. Application of all these tools can ensure better genetic gains, reduce length of selection cycles, and facilitate cultivar development to meet the future demand for food and fodder.

  6. Nitrogen removal and nitrate leaching for two perennial, sod-based forage systems receiving dairy effluent.

    Science.gov (United States)

    Woodard, Kenneth R; French, Edwin C; Sweat, Lewin A; Graetz, Donald A; Sollenberger, Lynn E; Macoon, Bisoondat; Portier, Kenneth M; Rymph, Stuart J; Wade, Brett L; Prine, Gordon M; Van Horn, Harold H

    2003-01-01

    In northern Florida, year-round forage systems are used in dairy effluent sprayfields to reduce nitrate leaching. Our purpose was to quantify forage N removal and monitor nitrate N (NO3(-)-N) concentration below the rooting zone for two perennial, sod-based, triple-cropping systems over four 12-mo cycles (1996-2000). The soil is an excessively drained Kershaw sand (thermic, uncoated Typic Quartzip-samment). Effluent N rates were 500, 690, and 910 kg ha(-1) per cycle. Differences in N removal between a corn (Zea mays L.)-bermudagrass (Cynodon spp.)-rye (Secale cereale L.) system (CBR) and corn-perennial peanut (Arachis glabrata Benth.)-rye system (CPR) were primarily related to the performance of the perennial forages. Nitrogen removal of corn (125-170 kg ha(-1)) and rye (62-90 kg ha(-1)) was relatively stable between systems and among cycles. The greatest N removal was measured for CBR in the first cycle (408 kg ha(-1)), with the bermudagrass removing an average of 191 kg N ha(-1). In later cycles, N removal for bermudagrass declined because dry matter (DM) yield declined. Yield and N removal of perennial peanut increased over the four cycles. Nitrate N concentrations below the rooting zone were lower for CBR than CPR in the first two cycles, but differences were inconsistent in the latter two. The CBR system maintained low NO3(-)-N leaching in the first cycle when the bermudagrass was the most productive; however, it was not a sustainable system for long-term prevention of NO3(-)-N leaching due to declining bermudagrass yield in subsequent cycles. For CPR, effluent N rates > or = 500 kg ha(-1) yr(-1) have the potential to negatively affect ground water quality.

  7. Transcriptional responses of Italian ryegrass during interaction with Xanthomonas translucens pv. graminis reveal novel candidate genes for bacterial wilt resistance

    DEFF Research Database (Denmark)

    Wichmann, Fabienne; Asp, Torben; Widmer, Franko

    2011-01-01

    Xanthomonas translucens pv. graminis (Xtg) causes bacterial wilt, a severe disease of forage grasses such as Italian ryegrass (Lolium multiflorum Lam.). In order to gain a more detailed understanding of the genetic control of resistance mechanisms and to provide prerequisites for marker assisted...... selection, the partial transcriptomes of two Italian ryegrass genotypes, one resistant and one susceptible to bacterial wilt were compared at four time points after Xtg infection. A cDNA microarray developed from a perennial ryegrass (Lolium perenne) expressed sequence tag set consisting of 9,990 unique...

  8. Reconsidering the generation time hypothesis based on nuclear ribosomal ITS sequence comparisons in annual and perennial angiosperms

    Directory of Open Access Journals (Sweden)

    Fiz-Palacios Omar

    2008-12-01

    in many comparisons, in cases of significant rate heterogeneity annuals frequently exhibited faster substitution rates. Our results suggest that annual taxa may exhibit a less than 2-fold rate acceleration at ITS. Since the rate difference is small and ITS lacks statistical power to reject rate homogeneity, further studies with greater power will be required to adequately test the hypothesis that annual and perennial plants have heterogeneous substitution rates. Arabidopsis sequence data suggest that relative rate tests based on multiple loci may be able to distinguish a weak acceleration in annual plants. The failure to detect rate heterogeneity with ITS in past studies may be largely a product of low statistical power.

  9. Genomic prediction in a breeding program of perennial ryegrass

    DEFF Research Database (Denmark)

    Fé, Dario; Ashraf, Bilal; Greve-Pedersen, Morten

    2015-01-01

    We present a genomic selection study performed on 1918 rye grass families (Lolium perenne L.), which were derived from a commercial breeding program at DLF-Trifolium, Denmark. Phenotypes were recorded on standard plots, across 13 years and in 6 different countries. Variants were identified...... this set. Estimated Breeding Value and prediction accuracies were calculated trough two different cross-validation schemes: (i) k-fold (k=10); (ii) leaving out one parent combination at the time, in order to test for accuracy of predicting new families. Accuracies ranged between 0.56 and 0.97 for scheme (i....... A larger set of 1791 F2s were used as training set to predict EBVs of 127 synthetic families (originated from poly-crosses between 5-11 single plants) for heading date and crown rust resistance. Prediction accuracies were 0.93 and 0.57 respectively. Results clearly demonstrate considerable potential...

  10. Assessing genetic diversity of perennial ryegrass ( Lolium perenne L ...

    African Journals Online (AJOL)

    In this study, inter-simple sequence repeat (ISSR) markers were used to compare genetic diversity between commercial cultivars and natural germplasm which were obtained from Europe, Africa, Asia, and North America. There was a relatively high genetic variation in the whole collection judged by the polymorphism rate ...

  11. Establishing the basis for Genomic Prediction in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Fé, Dario

    2015-01-01

    Genomic Selection (GS) is a relatively new technology, which has already revolutionized animal breeding and which is expected to have a high impact on plant breeding. In contrast to traditional marker assisted breeding, which only focuses on specific genes. GS estimates the genetic value...

  12. A synteny-based draft genome sequence of the forage grass Lolium perenne

    DEFF Research Database (Denmark)

    Byrne, Stephen; Nagy, Istvan; Pfeifer, Matthias

    2015-01-01

    -family of the grass family (Poaceae). Transcriptome data was used to identify 28 455 gene models, and we utilized macro-co-linearity between perennial ryegrass and barley, and synteny within the grass family, to establish a synteny-based linear gene order. The gametophytic self-incompatibility mechanism enables...

  13. Ergovaline does not alter the severity of ryegrass staggers induced by lolitrem B.

    Science.gov (United States)

    Finch, S C; Vlaming, J B; Sutherland, B L; van Koten, C; Mace, W J; Fletcher, L R

    2018-03-01

    To investigate a possible interaction between lolitrem B and ergovaline by comparing the incidence and severity of ryegrass staggers in sheep grazing ryegrass (Lolium perenne) containing lolitrem B or ryegrass containing both lolitrem B and ergovaline. Ninety lambs, aged approximately 6 months, were grazed on plots of perennial ryegrass infected with either AR98 endophyte (containing lolitrem B), standard endophyte (containing lolitrem B and ergovaline) or no endophyte, for up to 42 days from 2 February 2010. Ten lambs were grazed on three replicate plots per cultivar. Herbage samples were collected for alkaloid analysis and lambs were scored for ryegrass staggers (scores from 0-5) weekly during the study. Any animal which was scored ≥4 was removed from the study. Concentrations of lolitrem B did not differ between AR98 and standard endophyte-infected pastures during the study period (p=0.26), and ergovaline was present only in standard endophyte pastures. Ryegrass staggers was observed in sheep grazing both the AR98 and standard endophyte plots, with median scores increasing in the third week of the study. Prior to the end of the 42-day grazing period, 22 and 17 animals were removed from the standard endophyte and AR98 plots, respectively, because their staggers scores were ≥4. The cumulative probability of lambs having scores ≥4 did not differ between animals grazing the two pasture types (p=0.41). There was no evidence for ergovaline increasing the severity of ryegrass staggers induced by lolitrem B. In situations where the severity of ryegrass staggers appears to be greater than that predicted on the basis of concentrations of lolitrem B, the presence of other tremorgenic alkaloids should be investigated.

  14. Cultivar identification by means of isoenzymes 2. Genetic variation at 4 enzyme loci in diploid ryegrass lolium-spp

    DEFF Research Database (Denmark)

    Nielsen, G.; Østergaard, H.; Johansen, Henrik

    1985-01-01

    gel electrophoresis. Cultivars were pairwise compared by means of allelic frequencies assuming Hardy-Weinberg proportions. At first, the comparisons were carried out for each locus separately. The 2 loci Pgi-2 and Got-3 distinguished perennial ryegrass cultivars fairly well, but the discrimination...

  15. Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne

    International Nuclear Information System (INIS)

    Rocheleau, Sylvie; Lachance, Bernard; Kuperman, Roman G.; Hawari, Jalal; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I.

    2008-01-01

    Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain. - Cyclic nitramine explosives accumulate in perennial ryegrass and exhibit distinct uptake patterns

  16. Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne

    Energy Technology Data Exchange (ETDEWEB)

    Rocheleau, Sylvie; Lachance, Bernard [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Kuperman, Roman G. [Edgewood Chemical Biological Center, 5183 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5424 (United States); Hawari, Jalal [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Thiboutot, Sonia; Ampleman, Guy [Defense Research and Development Canada, 2459 Pie IX Boulevard, Val Belair, Quebec G3J 1X5 (Canada); Sunahara, Geoffrey I. [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada)], E-mail: geoffrey.sunahara@cnrc-nrc.gc.ca

    2008-11-15

    Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain. - Cyclic nitramine explosives accumulate in perennial ryegrass and exhibit distinct uptake patterns.

  17. Dinitrogen fixation in white clover grown in pure stand and mixture with ryegrass estimated by the immobilized 15N isotope dilution method

    DEFF Research Database (Denmark)

    Jørgensen, F.V.; Jensen, E.S.; Schjørring, J.K.

    1999-01-01

    Dinitrogen fixation in white clover (Trifolium repens L.) grown in pure stand and mixture with perennial ryegrass (Lolium perenne L.) was determined in the field using N-15 isotope dilution and harvest of the shoots. The apparent transfer of clover N to perennial ryegrass was simultaneously...... assessed. The soil was labelled either by immobilizing N-15 in organic matter prior to establishment of the sward or by using the conventional labelling procedure in which N-15 fertilizer is added after sward establishment. Immobilization of N-15 in the soil organic matter has not previously been used...

  18. Co-fermentation of sewage sludge with ryegrass for enhancing hydrogen production: Performance evaluation and kinetic analysis.

    Science.gov (United States)

    Yang, Guang; Wang, Jianlong

    2017-11-01

    The low C/N ratio and low carbohydrate content of sewage sludge limit its application for fermentative hydrogen production. In this study, perennial ryegrass was added as the co-substrate into sludge hydrogen fermentation with different mixing ratios for enhancing hydrogen production. The results showed that the highest hydrogen yield of 60mL/g-volatile solids (VS) added was achieved when sludge/perennial ryegrass ratio was 30:70, which was 5 times higher than that from sole sludge. The highest VS removal of 21.8% was also achieved when sludge/perennial ryegrass ratio was 30:70, whereas VS removal from sole sludge was only 0.7%. Meanwhile, the co-fermentation system simultaneously improved hydrogen production efficiency and organics utilization of ryegrass. Kinetic analysis showed that the Cone model fitted hydrogen evolution better than the modified Gompertz model. Furthermore, hydrogen yield and VS removal increased with the increase of dehydrogenase activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Effect of rhamnolipids on the uptake of PAHs by ryegrass

    International Nuclear Information System (INIS)

    Zhu Lizhong; Zhang Ming

    2008-01-01

    A hydroponic experiment was conducted to investigate the effect of rhamnolipids, a biosurfactant, on the uptake of polycyclic aromatic hydrocarbons (PAHs) by ryegrass. Results showed that rhamnolipids could enhance the uptake of PAHs by ryegrass roots. With increasing concentration of rhamnolipids, the PAH content in ryegrass roots initially increased and then decreased, while the PAH content in ryegrass shoots did not change. Batch studies also showed that the sorption of phenanthrene by fresh ryegrass roots was dependent on rhamnolipid concentration and showed the same trends as the uptake experiment. The increase of permeability of ryegrass root cells with the increase of rhamnolipid concentration may lead to the initial enhancement of PAH content in ryegrass roots, and the decrease of PAH adsorption onto the root surface with further increase of rhamnolipids led to the decrease of PAH content in ryegrass roots. - Rhamnolipids, a biosurfactant, can promote the uptake of PAHs by ryegrass, which indicates a potential application of surfactant-enhanced phytoremediation

  20. Effect of rhamnolipids on the uptake of PAHs by ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Lizhong [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China); Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, Zhejiang University, Hangzhou, Zhejiang 310029 (China)], E-mail: zlz@zju.edu.cn; Zhang Ming [Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang 310028 (China)], E-mail: zhangming@zju.edu.cn

    2008-11-15

    A hydroponic experiment was conducted to investigate the effect of rhamnolipids, a biosurfactant, on the uptake of polycyclic aromatic hydrocarbons (PAHs) by ryegrass. Results showed that rhamnolipids could enhance the uptake of PAHs by ryegrass roots. With increasing concentration of rhamnolipids, the PAH content in ryegrass roots initially increased and then decreased, while the PAH content in ryegrass shoots did not change. Batch studies also showed that the sorption of phenanthrene by fresh ryegrass roots was dependent on rhamnolipid concentration and showed the same trends as the uptake experiment. The increase of permeability of ryegrass root cells with the increase of rhamnolipid concentration may lead to the initial enhancement of PAH content in ryegrass roots, and the decrease of PAH adsorption onto the root surface with further increase of rhamnolipids led to the decrease of PAH content in ryegrass roots. - Rhamnolipids, a biosurfactant, can promote the uptake of PAHs by ryegrass, which indicates a potential application of surfactant-enhanced phytoremediation.

  1. Annual maize and perennial grass-clover strip cropping for increased resource use efficiency and productivity using organic farming practice as a model

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Johansen, Anders; Carter, Mette Sustmann

    2013-01-01

    A cropping system was designed to fulfill the increasing demand for biomass for food and energy without decreasing long term soil fertility. A field experiment was carried out including alternating strips of annual maize (Zea mays L.) and perennial ryegrass (Lolium perenne L.) – clover (Trifolium...

  2. Remediation of anthracene in mycorrhizospheric soil using ryegrass ...

    African Journals Online (AJOL)

    ... such as polycyclic aromatic hydrocarbons (PAHs), pesticides and radionuclides. ... In the present study, biodegradation of anthracene was studied using ryegrass in ... bioremediation, Lolium multiflorum, arbuscular mycorrhizal fungi, PAHs.

  3. Manejo da palha de azevém, da adubação de base e da água de drenagem na produção de arroz irrigado Management of ryegrass straw, fertilizer and drainage water, on flooded rice prodution

    Directory of Open Access Journals (Sweden)

    Alexandre Swarowsky

    2004-04-01

    Full Text Available Sistemas com mínimo revolvimento do solo são favoráveis ao controle de plantas daninhas, à utilização mais intensiva dos solos de várzea e à rentabilidade do orizicultor, mas apresentam algumas limitações, como a produção de substâncias que podem ser tóxicas ao arroz, bem como alterações na disponibilidade de nutrientes em ambientes alagados. O trabalho teve como objetivo comparar diferentes sistemas de manejo da palha de azevém, da adubação de base, e da drenagem, no rendimento de grãos de arroz e nos componentes da produção. O experimento foi conduzido na Universidade Federal de Santa Maria. Foram avaliados três níveis de manejo da resteva de azevém (planta de azevém em pé, planta de azevém incorporada e sem a planta de azevém, três condições de adubação (sem adubação, adubação do arroz 100% aplicada na semeadura do azevém e adubação do arroz 100% aplicada na semeadura do arroz e dois manejos da água de drenagem (inundação convencional em condições de campo e inundação sem drenagem. Os resultados obtidos permitem concluir que, na cultura do arroz irrigado por inundação, a incorporação da palha de azevém e a aplicação da adubação para o arroz na semeadura do azevém não afetam o rendimento de grãos e os componentes da produção. Entretanto, a ausência de drenagem interna no solo reduz o rendimento de grãos de arroz, o número de panículas e o número de grãos por panícula.Cultivation systems with minimum tillage are used to minimize red rice incidence, improving crop yield and the agricultural exploration of lowland soils. However, some limitations are present such as toxic substances due to anaerobic straw decomposition (prejudicial to rice plant establishment, as well as alterations on some available nutrients under flooded soil water conditions. The objective of this work was to compare different drainage systems; ryegrass straw management and time of fertilizer application on

  4. First Case of Glufosinate-Resistant Rigid Ryegrass (Lolium rigidum Gaud. in Greece

    Directory of Open Access Journals (Sweden)

    Ilias S. Travlos

    2018-03-01

    Full Text Available Repeated applications of the same herbicide(s, which are characterized by the same mode of action, increase selection pressure, which in turn favours the evolution of herbicide-resistant weeds. Glufosinate is a broad-spectrum non-selective herbicide being used for weed control for many years around the world. Rigid ryegrass (Lolium rigidum Gaud. is an economically important grass weed in Greece. Recent complaints by growers about control failure of rigid ryegrass with glufosinate require further investigation and have been the basis of this study. The objectives of this study were to confirm the existence of glufosinate-resistant L. rigidum in Greece and evaluate the effect of L. rigidum growth stage on glufosinate efficacy. Twenty populations of rigid ryegrass from Greece were sampled from five regions, and whole plant dose–response studies were conducted for five populations under controlled conditions with eight rates of glufosinate (0.0, 0.098, 0.187, 0.375, 0.75, 1.5, 3.0, and 6.0 kg a.i. ha−1. Glufosinate resistance was confirmed in three out of five populations with the level of resistance ranging from three-to seven-fold compared with the susceptible populations based on above-ground biomass reduction. Results also revealed that the level of glufosinate-resistance of rigid ryegrass was dependent on the growth stage at which it was applied.

  5. Nitrogen utilization and transformation in red soil fertilized with urea and ryegrass

    International Nuclear Information System (INIS)

    Wu Gang; Zhang Qinzheng; Ye Qingfu; Zhu Zhujun; Xi Haifu; He Zhenli

    1998-01-01

    The influence of fertilization with urea and ryegrass on nitrogen utilization and transformation in red soil has been studied by using 15 N tracer method. When urea and ryegrass were applied alone or in combination, the percentage of N uptaken by ryegrass for labelled urea was 3 and 1.7 times that from labelled ryegrass for the application rate of 200 mgN·kg -1 and 100 mgN·kg -1 , respectively; combining application of ryegrass and urea reduced uptake of urea N and increased uptake of ryegrass N by ryegrass plant, but the percentage of N residue in soil increased for urea and decreased for ryegrass; when urea and ryegrass were applied alone, the percentage of N residue in soil from labelled ryegrass was more than 69% while that from labelled urea was less than 25%, and much more ryegrass N was incorporated into humus than urea N

  6. Genetic and environmental variation in a commercial breeding program of perennial ryegrass

    DEFF Research Database (Denmark)

    Fé, Dario; Pedersen, Morten Greve; Jensen, Christian S

    2015-01-01

    on forage yield (green and dry matter) and six traits scored by visual inspection (i.e., rust resistance, aftermath heading, spring growth, density, winter hardiness, and heading date). Data were analyzed with linear mixed models, including fixed effects (trial and control varieties, within year...... for future GSbased breeding programs. Forage yield showed family heritabilities of up to 0.30 across locations and up to 0.60 within a location. Similar or moderately lower values were found for the other traits. In particular, the heritabilities of rust resistance and aftermath heading were very promising...

  7. Perennial Environment Observatory

    International Nuclear Information System (INIS)

    Plas, Frederic

    2014-07-01

    The Perennial Environment Observatory [Observatoire Perenne de l'Environnement - OPE] is a unique approach and infrastructure developed and implemented by ANDRA, the French National Radioactive Waste Management Agency, as part of its overall project of deep geological disposal for radioactive waste. Its current mission is to assess the initial state of the rural (forest, pasture, open-field and aquatic) environment, prior to repository construction. This will be followed in 2017 (pending construction authorizations) and for a period exceeding a century, by monitoring of any impact the repository may have on the environment. In addition to serving its own industrial purpose of environmental monitoring, ANDRA also opens the OPE approach, infrastructure and acquired knowledge (database...) to the scientific community to support further research on long term evolution of the environment subjected to natural and anthropogenic stresses, and to contribute to a better understanding of the interaction between the various compartments of the environment

  8. Milk production potential of two ryegrass cultivars with different total ...

    African Journals Online (AJOL)

    The aim of the study was to compare a new Italian ryegrass (Lolium multiflorum) cultivar (Enhancer), bred to contain a high total non-structural carbohydrate content, with the cultivar, Dargle, in terms of dry matter (DM) production, nutritional value, carrying capacity and milk production. The ryegrass cultivars were sown (25 ...

  9. Alcohol consumption and the risk of self-reported perennial and seasonal allergic rhinitis in young adult women in a population-based cohort study

    DEFF Research Database (Denmark)

    Bendtsen, P; Grønbæk, M; Kjær, S. K.

    2008-01-01

    Background Alcohol consumption has been suggested to be associated with the development of allergic rhinitis (AR), but there is limited data on the topic. Objectives The objective of this study was to investigate the association between alcohol consumption and the risk of developing AR among young...... women. Methods Five thousand eight hundred and seventy Danish women aged 20-29 years participated in a prospective cohort study, and were free of seasonal and perennial AR at baseline (1991-1993). Alcohol consumption was assessed by a food frequency questionnaire. The main outcome measures were self......-reported information on seasonal and perennial AR debuting during a mean follow-up period of 7.8 years. Results During follow-up, 831 women developed seasonal AR and 523 women developed perennial AR, corresponding to 14% and 9%. Alcohol consumption was positively associated with the risk of developing perennial AR...

  10. Effect of in situ soil amendments on arsenic uptake in successive harvests of ryegrass (Lolium perenne cv Elka) grown in amended As-polluted soils

    International Nuclear Information System (INIS)

    Hartley, William; Lepp, Nicholas W.

    2008-01-01

    Several iron-bearing additives, selected for their potential ability to adsorb anions, were evaluated for their effectiveness in attenuation of arsenic (As) in three soils with different sources of contamination. Amendments used were lime, goethite (α-FeOOH) (crystallised iron oxide) and three iron-bearing additives, iron grit, Fe II and Fe III sulphates plus lime, applied at 1% w/w. Sequential extraction schemes conducted on amended soils determined As, Cu, Zn and Ni fractionation. Plant growth trials using perennial ryegrass (Lolium perenne var. Elka) assessed shoot As uptake. This was grown in the contaminated soils for 4 months, during which time grass shoots were successively harvested every 3 weeks. Goethite increased biomass yields, but clear differences were observed in As transfer rates with the various iron oxides. In conclusion, whilst Fe-oxides may be effective in situ amendments, reducing As bioavailability, their effects on plant growth require careful consideration. Soil-plant transfer of As was not completely halted by any amendment. - Arsenic attenuation is illustrated using Fe-based amendments, their efficacy providing different indicators of success

  11. Development of Perennial Grain Sorghum

    Directory of Open Access Journals (Sweden)

    Stan Cox

    2018-01-01

    Full Text Available Perennial germplasm derived from crosses between Sorghum bicolor and either S. halepense or S. propinquum is being developed with the goal of preventing and reversing soil degradation in the world’s grain sorghum-growing regions. Perennial grain sorghum plants produce subterranean stems known as rhizomes that sprout to form the next season’s crop. In Kansas, breeding perennial sorghum involves crossing S. bicolor cultivars or breeding lines to S. halepense or perennial S. bicolorn × S. halepense breeding lines, selecting perennial plants from F2 or subsequent populations, crossing those plants with S. bicolor, and repeating the cycle. A retrospective field trial in Kansas showed that selection and backcrossing during 2002–2009 had improved grain yields and seed weights of breeding lines. Second-season grain yields of sorghum lines regrowing from rhizomes were similar to yields in the first season. Further selection cycles have been completed since 2009. Many rhizomatous lines that cannot survive winters in Kansas are perennial at subtropical or tropical locations in North America and Africa. Grain yield in Kansas was not correlated with rhizomatousness in either Kansas or Uganda. Genomic regions affecting rhizome growth and development have been mapped, providing new breeding tools. The S. halepense gene pool may harbor many alleles useful for improving sorghum for a broad range of traits in addition to perenniality.

  12. Using Massive Multivariate NIRS Data in Ryegrass

    DEFF Research Database (Denmark)

    Edriss, Vahid; Greve-Pedersen, Morten; Jensen, Christian S

    2015-01-01

    Near infrared spectroscopy (NIRS) analytical techniques is a simple, fast and low cost method of high dimensional phenotyping compared to usual chemical techniques. To use this method there is no need for special sample preparation. The aim of this study is to use NIRS data to predict plant traits...... (e.g. dry matter, protein content, etc.) for the next generation. In total 1984 NIRS data from 995 ryegrass families (first cut) were used. The Absorption of radiation in the region of 960 – 1690 nm in every 2 nm distance produced 366 bins to represent the NIRS spectrum. The amount of genetic...

  13. Herbicide Safeners Decrease Sensitivity to Herbicides Inhibiting Acetolactate-Synthase and Likely Activate Non-Target-Site-Based Resistance Pathways in the Major Grass Weed Lolium sp. (Rye-Grass

    Directory of Open Access Journals (Sweden)

    Arnaud Duhoux

    2017-08-01

    Full Text Available Herbicides are currently pivotal to control weeds and sustain food security. Herbicides must efficiently kill weeds while being as harmless as possible for crops, even crops taxonomically close to weeds. To increase their selectivity toward crops, some herbicides are sprayed in association with safeners that are bioactive compounds exacerbating herbicide-degrading pathways reputedly specifically in crops. However, exacerbated herbicide metabolism is also a key mechanism underlying evolved non-target-site-based resistance to herbicides (NTSR in weeds. This raised the issue of a possible role of safeners on NTSR evolution in weeds. We investigated a possible effect of the respective field rates of the two broadly used safeners cloquintocet-mexyl and mefenpyr-diethyl on the sensitivity of the troublesome global weed Lolium sp. (rye-grass to the major herbicides inhibiting acetolactate-synthase (ALS pyroxsulam and iodosulfuron + mesosulfuron, respectively. Three Lolium sp. populations were studied in three series of experiments. The first experiment series compared the frequencies of plants surviving application of each herbicide alone or in association with its safener. Safener co-application caused a net increase ranging from 5.0 to 46.5% in the frequency of plants surviving the field rate of their associated herbicide. In a second series of experiments, safener effect was assessed on individual plant sensitivity using vegetative propagation. A reduction in sensitivity to pyroxsulam and to iodosulfuron + mesosulfuron was observed for 44.4 and 11.1% of the plants in co-treatment with cloquintocet-mexyl and mefenpyr-diethyl, respectively. A third series of experiments investigated safener effect on the expression level of 19 Lolium sp. NTSR marker genes. Safeners showed an enhancing effect on the expression level of 10 genes. Overall, we demonstrated that cloquintocet-mexyl and mefenpyr-diethyl both reduced the sensitivity of Lolium sp. to their

  14. Herbicide Safeners Decrease Sensitivity to Herbicides Inhibiting Acetolactate-Synthase and Likely Activate Non-Target-Site-Based Resistance Pathways in the Major Grass Weed Lolium sp. (Rye-Grass).

    Science.gov (United States)

    Duhoux, Arnaud; Pernin, Fanny; Desserre, Diane; Délye, Christophe

    2017-01-01

    Herbicides are currently pivotal to control weeds and sustain food security. Herbicides must efficiently kill weeds while being as harmless as possible for crops, even crops taxonomically close to weeds. To increase their selectivity toward crops, some herbicides are sprayed in association with safeners that are bioactive compounds exacerbating herbicide-degrading pathways reputedly specifically in crops. However, exacerbated herbicide metabolism is also a key mechanism underlying evolved non-target-site-based resistance to herbicides (NTSR) in weeds. This raised the issue of a possible role of safeners on NTSR evolution in weeds. We investigated a possible effect of the respective field rates of the two broadly used safeners cloquintocet-mexyl and mefenpyr-diethyl on the sensitivity of the troublesome global weed Lolium sp. (rye-grass) to the major herbicides inhibiting acetolactate-synthase (ALS) pyroxsulam and iodosulfuron + mesosulfuron, respectively. Three Lolium sp. populations were studied in three series of experiments. The first experiment series compared the frequencies of plants surviving application of each herbicide alone or in association with its safener. Safener co-application caused a net increase ranging from 5.0 to 46.5% in the frequency of plants surviving the field rate of their associated herbicide. In a second series of experiments, safener effect was assessed on individual plant sensitivity using vegetative propagation. A reduction in sensitivity to pyroxsulam and to iodosulfuron + mesosulfuron was observed for 44.4 and 11.1% of the plants in co-treatment with cloquintocet-mexyl and mefenpyr-diethyl, respectively. A third series of experiments investigated safener effect on the expression level of 19 Lolium sp. NTSR marker genes. Safeners showed an enhancing effect on the expression level of 10 genes. Overall, we demonstrated that cloquintocet-mexyl and mefenpyr-diethyl both reduced the sensitivity of Lolium sp. to their associated ALS

  15. Development of SSR Markers Based on Transcriptome Sequencing and Association Analysis with Drought Tolerance in Perennial Grass Miscanthus from China

    Directory of Open Access Journals (Sweden)

    Gang Nie

    2017-05-01

    Full Text Available Drought has become a critical environmental stress affecting on plant in temperate area. As one of the promising bio-energy crops to sustainable biomass production, the genus Miscanthus has been widely studied around the world. However, the most widely used hybrid cultivar among this genus, Miscanthus × giganteus is proved poor drought tolerance compared to some parental species. Here we mainly focused on Miscanthus sinensis, which is one of the progenitors of M. × giganteus providing a comparable yield and well abiotic stress tolerance in some places. The main objectives were to characterize the physiological and photosynthetic respond to drought stress and to develop simple sequence repeats (SSRs markers associated with drought tolerance by transcriptome sequencing within an originally collection of 44 Miscanthus genotypes from southwest China. Significant phenotypic differences were observed among genotypes, and the average of leaf relative water content (RWC were severely affected by drought stress decreasing from 88.27 to 43.21%, which could well contribute to separating the drought resistant and drought sensitive genotype of Miscanthus. Furthermore, a total of 16,566 gene-associated SSRs markers were identified based on Illumina RNA sequencing under drought conditions, and 93 of them were randomly selected to validate. In total, 70 (75.3% SSRs were successfully amplified and the generated loci from 30 polymorphic SSRs were used to estimate the genetic differentiation and population structure. Finally, two optimum subgroups of the population were determined by structure analysis and based on association analysis, seven significant associations were identified including two markers with leaf RWC and five markers with photosynthetic traits. With the rich sequencing resources annotation, such associations would serve an efficient tool for Miscanthus drought response mechanism study and facilitate genetic improvement of drought resistant for

  16. Bicarbonate as tracer for plant assimilated C and homogeneity of 14C and 15N distribution in ryegrass and white clover tissue by alternative labeling approaches

    DEFF Research Database (Denmark)

    Rasmussen, Jim; Kusliene, Gedrime; Jacobsen, Ole Stig

    2013-01-01

    that 15N also had a heterogeneous distribution (up to two orders of magnitude). Conclusion Bicarbonate can efficiently be used to introduce 14C or 13C into plant via the leaf-labeling method. Both 14C and 15N showed heterogeneous distribution in the plant, although the distribution of 15N was more even......Aims: Application of carbon (C) and nitrogen (N) isotopes is an essential tool to study C and N flows in plant-soil-microorganisms systems. When targeting single plants in a community the tracers need to be added via e.g., leaf-labeling or stem-feeding approaches. In this study we: (i) investigated...... if bicarbonate can be used to introduce 14C (or 13C) into white clover and ryegrass, and (ii) compared the patterns of 14C and 15N allocation in white clover and ryegrass to evaluate the homogeneity of tracer distribution after two alternative labeling approaches. Methods Perennial ryegrass and white clover were...

  17. Native herbaceous perennials as ornamentals

    DEFF Research Database (Denmark)

    Larsen, Bjarne; Ørgaard, Marian

    2013-01-01

    Gardening with native perennials is a way to bring nature closer to urban citizens and bring up reflections on nature in a busy world. During three seasons of trialing Salvia pratensis, Dianthus deltoides, Campanula trachelium, Vincetoxicum hirundinaria, Saxifraga granulata, Plantago media and P...

  18. Managing for Multifunctionality in Perennial Grain Crops

    Science.gov (United States)

    Ryan, Matthew R; Crews, Timothy E; Culman, Steven W; DeHaan, Lee R; Hayes, Richard C; Jungers, Jacob M; Bakker, Matthew G

    2018-01-01

    Abstract Plant breeders are increasing yields and improving agronomic traits in several perennial grain crops, the first of which is now being incorporated into commercial food products. Integration strategies and management guidelines are needed to optimize production of these new crops, which differ substantially from both annual grain crops and perennial forages. To offset relatively low grain yields, perennial grain cropping systems should be multifunctional. Growing perennial grains for several years to regenerate soil health before rotating to annual crops and growing perennial grains on sloped land and ecologically sensitive areas to reduce soil erosion and nutrient losses are two strategies that can provide ecosystem services and support multifunctionality. Several perennial cereals can be used to produce both grain and forage, and these dual-purpose crops can be intercropped with legumes for additional benefits. Highly diverse perennial grain polycultures can further enhance ecosystem services, but increased management complexity might limit their adoption. PMID:29662249

  19. Cross-resistance to herbicides in annual ryegrass (lolium rigidum)

    International Nuclear Information System (INIS)

    Christopher, J.T.; Powles, S.B.; Liljegren, D.R.; Holtum, J.A.M.

    1991-01-01

    Lolium rigidum Gaud. biotype SLR31 is resistant to the herbicide diclofop-methyl and cross-resistant to several sulfonylurea herbicides. Wheat and the cross-resistant ryegrass exhibit similar patterns of resistance to sulfonylurea herbicides, suggesting that the mechanism of resistance may be similar. Cross-resistant ryegrass is also resistant to the wheat-selective imidazolinone herbicide imazamethabenz. The cross-resistant biotype SLR31 metabolized [phenyl-U- 14 C]chlorsulfuron at a faster rate than a biotype which is susceptible to both diclofop-methyl and chlorsulfuron. A third biotype which is resistant to diclofop-methyl but not to chlorsulfuron metabolized chlorsulfuron at the same rate as the susceptible biotype. The increased metabolism of chlorsulfuron observed in the cross-resistant biotype is, therefore, correlated with the patterns of resistance observed in these L. rigidum biotypes. During high performance liquid chromatography analysis the major metabolite of chlorsulfuron in both susceptible and cross-resistant ryegrass coeluted with the major metabolite produced in wheat. The major product is clearly different from the major product in the tolerant dicot species, flax (Linium usitatissimum). The elution pattern of metabolites of chlorsulfuron was the same for both the susceptible and cross-resistant ryegrass but the cross-resistant ryegrass metabolized chlorsulfuron more rapidly. The investigation of the dose response to sulfonylurea herbicides at the whole plant level and the study of the metabolism of chlorsulfuron provide two independent sets of data which both suggest that the resistance to chlorsulfuron in cross-resistant ryegrass biotype SLR31 involves a wheat-like detoxification system

  20. Identification of companion small grains for Midmar Italian ryegrass ...

    African Journals Online (AJOL)

    Rye was the most successful small grain in being able to fill the winter gap in the fodder flow of Midmar ryegrass. The small grains on average contributed about 25% towards the total DM production in the small grain-Midmar mixtures. Oats, although initially slow, had significantly (P < 0, 05) higher yields than any of the ...

  1. Rumen degradation characteristics of ryegrass herbage and ryegrass silage are affected by interactions between stage of maturity and nitrogen fertilisation rate

    NARCIS (Netherlands)

    Heeren, J.A.H.; Podesta, S.C.; Hatew, B.; Klop, G.; Laar, van H.; Bannink, A.; Warner, D.; Jonge, de L.H.; Dijkstra, J.

    2014-01-01

    The objective of this experiment was to evaluate interaction effects between stage of maturity and N fertilization rate on rumen degradation characteristics determined with nylon bag incubations of ryegrass herbages and ryegrass silage. Grass herbage (n = 4) was cut after 3 or 5 weeks of regrowth

  2. Allelopathic effect of ryegrass (lolium persicum) and wild mustard (sinapis arvensis) on barley

    International Nuclear Information System (INIS)

    Baziar, M.R.; Farahvash, F.; Mirshekari, B.; Rashidi, V.

    2014-01-01

    Most crop plants and weeds have allelopathic effects and analysis of these effects on plants in crop alteration and successive planting is very important. In this research the allelopathic ability of different parts and concentrations of two weeds, Lolium Persicum (Ryegrass) and Sinapis arvensis (wild mustered), on growth characteristics of two barley varieties was studied in the greenhouse using a completely randomized design with four replications. Test factors consisted of two barley varieties (Valfajr and Rehane), three weed organs (root, stalk, leaf) and four concentrations of extracts of weed organs (25, 50, 75 and control or distilled water). After the preparation of extracts of different weed organs with different concentrations, their effect on growth characteristics of barley plant was evaluated. Finally, seedling length, rootlet length caulicle length, wet weight of seedling, dry weight of seedling were measured. Also, the above two seeds had significant effects on the two strains of barley and could influence growth characteristics of barley. Based on the results of present study, one can argue that Ryegrass (Lolium Persicum) and wild mustard (Sinapis arvensis) can strongly affect germination, growth and performance of barley through production of chemical materials with allelopathic properties, leading unfavorable growth and product yield. (author)

  3. Estimated Perennial Streams of Idaho and Related Geospatial Datasets

    Science.gov (United States)

    Rea, Alan; Skinner, Kenneth D.

    2009-01-01

    The perennial or intermittent status of a stream has bearing on many regulatory requirements. Because of changing technologies over time, cartographic representation of perennial/intermittent status of streams on U.S. Geological Survey (USGS) topographic maps is not always accurate and (or) consistent from one map sheet to another. Idaho Administrative Code defines an intermittent stream as one having a 7-day, 2-year low flow (7Q2) less than 0.1 cubic feet per second. To establish consistency with the Idaho Administrative Code, the USGS developed regional regression equations for Idaho streams for several low-flow statistics, including 7Q2. Using these regression equations, the 7Q2 streamflow may be estimated for naturally flowing streams anywhere in Idaho to help determine perennial/intermittent status of streams. Using these equations in conjunction with a Geographic Information System (GIS) technique known as weighted flow accumulation allows for an automated and continuous estimation of 7Q2 streamflow at all points along a stream, which in turn can be used to determine if a stream is intermittent or perennial according to the Idaho Administrative Code operational definition. The selected regression equations were applied to create continuous grids of 7Q2 estimates for the eight low-flow regression regions of Idaho. By applying the 0.1 ft3/s criterion, the perennial streams have been estimated in each low-flow region. Uncertainty in the estimates is shown by identifying a 'transitional' zone, corresponding to flow estimates of 0.1 ft3/s plus and minus one standard error. Considerable additional uncertainty exists in the model of perennial streams presented in this report. The regression models provide overall estimates based on general trends within each regression region. These models do not include local factors such as a large spring or a losing reach that may greatly affect flows at any given point. Site-specific flow data, assuming a sufficient period of

  4. Effects of Nitrogen Rate and Regrowth Interval on Perennial Ryegrass Fatty Acid Content during the Growing Season

    NARCIS (Netherlands)

    Witkowska, I.M.; Wever, C.J.G.; Gort, G.; Elgersma, A.

    2008-01-01

    The content of fatty acids (FA) in herbage is important for forage quality and animal-source foods, but there is a lack of knowledge on effects of agronomic practices, and on environmental factors related to seasonal variation in FA concentrations and FA composition. This research investigated the

  5. The effect of elevated ambient CO2 and temperature increase on rhizosphere of perennial ryegrass (Lolium perenne L.)

    Czech Academy of Sciences Publication Activity Database

    Šantrůčková, Hana; Elhottová, Dana; Loiseau, P.; Soussana, F.

    2000-01-01

    Roč. 46, č. 9 (2000), s. 397-403 ISSN 0370-663X R&D Projects: GA ČR GA206/99/1410 Grant - others:-(EV) EV5V-CT92-0169 Institutional research plan: CEZ:AV0Z6066911; CEZ:MSM 123100004 Subject RIV: EF - Botanics Impact factor: 0.256, year: 2000

  6. Variation in effective pollination rates in relation to the spatial and temporal distribution of pollen release in rejuvenated perennial ryegrass

    NARCIS (Netherlands)

    Treuren, van R.; Goossens, P.J.; Sevcikova, M.

    2006-01-01

    Genebank accessions stored as seed populations require periodic rejuvenation in order to maintain sufficient numbers of viable seeds. During rejuvenation the genetic composition of accessions may be altered for a variety of reasons, of which variation in pollination rates between plants is the least

  7. Predicting anthesis date of perennial ryegrass (Lolium perenne L.) with growing degree-days at heading

    DEFF Research Database (Denmark)

    Abel, Simon; Byrne, Stephen; Asp, Torben

    2018-01-01

    The agronomic significance of heading date in crop species is well documented; however, the date of anthesis is often less emphasized even though it has important applications for seed quality and yield. Moreover, the relationship between heading and anthesis is not well defined. We propose that ...

  8. Diurnal variation in ruminal pH on the digestibility of highly digestible perennial ryegrass during continuous culture fermentation.

    Science.gov (United States)

    Wales, W J; Kolver, E S; Thorne, P L; Egan, A R

    2004-06-01

    Dairy cows grazing high-digestibility pastures exhibit pronounced diurnal variation in ruminal pH, with pH being below values considered optimal for digestion. Using a dual-flow continuous culture system, the hypothesis that minimizing diurnal variation in pH would improve digestion of pasture when pH was low, but not at a higher pH, was tested. Four treatments were imposed, with pH either allowed to exhibit normal diurnal variation around an average pH of 6.1 or 5.6, or maintained at constant pH. Digesta samples were collected during the last 3 d of each of four, 9-d experimental periods. A constant pH at 5.6 compared with a constant pH of 6.1 reduced the digestibility of organic matter (OM), neutral detergent (NDF), and acid detergent fiber (ADF) by 7, 14, and 21%, respectively. When pH was allowed to vary (averaging 5.6), digestion of OM, NDF, and ADF were reduced by 15,30, and 36%, respectively, compared with pH varying at 6.1. There was little difference in digestion parameters when pH was either constant or varied with an average pH of 6.1. However, when average pH was 5.6, maintaining a constant pH significantly increased digestion of OM, NDF, and ADF by 5, 25, and 24% compared with a pH that exhibited normal diurnal variation. These in vitro results show that gains in digestibility and potential milk production can be made by minimizing diurnal variation in ruminal pH, but only when ruminal pH is low (5.6). However, larger gains in productivity can be achieved by increasing average daily ruminal pH from 5.6 to 6.1.

  9. Molecular characterization of cytoplasmic male sterility (CMS) in perennial ryegrass ( Lolium perenne L.)

    DEFF Research Database (Denmark)

    Islam, Md. Shofiqul; Møller, Ian Max; Studer, Bruno

    2011-01-01

    to increase biomass yield, improve nutritional value and tolerance towards abiotic and biotic stress. Cytoplasmic male sterility (CMS) is an efficient tool to control pollination for hybrid seed production. In order to identify the causative polymorphism of the CMS phenotype, a cytoplasmic male sterile plant...

  10. Evaluation of Turf-type Interspecific Hybrids of Meadow Fescue with Perennial Ryegrass for Improved Stress Tolerance

    Czech Academy of Sciences Publication Activity Database

    Barnes, B.D.; Kopecký, David; Lukaszewski, A.J.; Baird, J. H.

    2014-01-01

    Roč. 54, č. 1 (2014), s. 355-365 ISSN 0011-183X R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : LOLIUM-FESTUCA COMPLEX * TALL FESCUE * INTERGENERIC HYBRIDS Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.575, year: 2014

  11. Effect of silage from ryegrass intercropped with winter or common vetch for grazing dairy cows in small-scale dairy systems in Mexico.

    Science.gov (United States)

    Hernández-Ortega, Martha; Heredia-Nava, Darwin; Espinoza-Ortega, Angelica; Sánchez-Vera, Ernesto; Arriaga-Jordán, Carlos M

    2011-06-01

    The objective was to determine the effect of including silages of annual ryegrass (Lolium multiflorum) intercropped with winter vetch (Vicia villosa) (ARG-VV) or with common vetch (Vicia sativa) (ARG-VS) compared with maize silage (MS) on milk yield and milk composition of dairy cows grazing cultivated perennial ryegrass-white clover pastures with supplemented concentrate during the dry season. Six Holstein dairy cows with a mean yield of 19.0 kg/cow/day at the beginning of the experiment were randomly assigned to a 3 × 3 repeated Latin square. Treatments were: 8 h/day intensive grazing, 3.6 kg of dry matter (DM) per cow per day of concentrate plus MS, and ARG-VV or ARG-VS ad libitum at a stocking rate of 3.0 cows/ha for three experimental periods of 3 weeks each. Milk yield (MY) and milk composition, live weight and body condition score as well as silage and concentrate intakes were recorded during the third week of each experimental period, and pasture intake was estimated indirectly from utilised metabolisable energy. Economic analysis was obtained by preparing partial budgets. There were no statistical differences (P > 0.10) in MY, milk fat or protein content nor for live weight, but there was significant difference (P dairy production systems in the dry season as it is comparable to MS in animal performance and slightly better in economic terms.

  12. EST-derived SSR markers used as anchor loci for the construction of a consensus linkage map in ryegrass (Lolium spp.

    Directory of Open Access Journals (Sweden)

    Studer Bruno

    2010-08-01

    Full Text Available Abstract Background Genetic markers and linkage mapping are basic prerequisites for marker-assisted selection and map-based cloning. In the case of the key grassland species Lolium spp., numerous mapping populations have been developed and characterised for various traits. Although some genetic linkage maps of these populations have been aligned with each other using publicly available DNA markers, the number of common markers among genetic maps is still low, limiting the ability to compare candidate gene and QTL locations across germplasm. Results A set of 204 expressed sequence tag (EST-derived simple sequence repeat (SSR markers has been assigned to map positions using eight different ryegrass mapping populations. Marker properties of a subset of 64 EST-SSRs were assessed in six to eight individuals of each mapping population and revealed 83% of the markers to be polymorphic in at least one population and an average number of alleles of 4.88. EST-SSR markers polymorphic in multiple populations served as anchor markers and allowed the construction of the first comprehensive consensus map for ryegrass. The integrated map was complemented with 97 SSRs from previously published linkage maps and finally contained 284 EST-derived and genomic SSR markers. The total map length was 742 centiMorgan (cM, ranging for individual chromosomes from 70 cM of linkage group (LG 6 to 171 cM of LG 2. Conclusions The consensus linkage map for ryegrass based on eight mapping populations and constructed using a large set of publicly available Lolium EST-SSRs mapped for the first time together with previously mapped SSR markers will allow for consolidating existing mapping and QTL information in ryegrass. Map and markers presented here will prove to be an asset in the development for both molecular breeding of ryegrass as well as comparative genetics and genomics within grass species.

  13. Considerations for Managing Agricultural Co-Existence between Transgenic and Non-Transgenic Cultivars of Outcrossing Perennial Forage Plants in Dairy Pastures

    Directory of Open Access Journals (Sweden)

    Kevin F. Smith

    2016-11-01

    Full Text Available Many of the major forage species used in agriculture are outcrossing and rely on the exchange of pollen between individuals for reproduction; this includes the major species used for dairy production in grazing systems: perennial ryegrass (Lolium perenne L. and white clover (Trifolium repens L.. Cultivars of these species have been co-existing since contrasting cultivars were developed using plant breeding, but the consequences and need for strategies to manage co-existence have been made more prominent with the advent of genetic modification. Recent technological developments have seen the experimental evaluation of genetically modified (GM white clover and perennial ryegrass, although there is no current commercial growing of GM cultivars of these species. Co-existence frameworks already exist for two major cross-pollinated grain crops (canola and maize in Europe, and for alfalfa (Medicago sativa L. in the US, so many of the principles that the industry has developed for co-existence in these crops such as detection techniques, segregation, and agronomic management provide lessons and guidelines for outcrossing forage species, that are discussed in this paper.

  14. Recent Progress in Perennial Buckwheat Development

    Directory of Open Access Journals (Sweden)

    Qing-Fu Chen

    2018-02-01

    Full Text Available Grains in the genus Fagopyrum have benefits to human health and are an excellent gluten-free raw material. Of all cereal foods, this genus has the highest total content of amino-acid nutrients necessary for humans; nutrients that are resistant to digestion (protein and starch resulting in their sustained release; higher dietary fiber content than key cereals, and is rich in a special healthy ingredient (flavonoids. Fagopyrum includes 24 species of which five are perennial. Among them, golden buckwheat (F.cymosum complex is the most important perennial buckwheat, which is not only used in Chinese medicine, but also has great potential in healthy food crop. In order to provide some clues for perennial crop studies and their industry development, this paper presents the state of perennial buckwheat research in terms of taxonomy; natural chemical products and pharmacological and health functions; genetics and evolution; breeding; and product development and utilization. The great advances such as successful interspecific crossing and its subsequent new perennial buckwheat varieties will speed up the development of the perennial buckwheat industry.

  15. Cumulative drought and land-use impacts on perennial vegetation across a North American dryland region

    Science.gov (United States)

    Munson, Seth M.; Long, A. Lexine; Wallace, Cynthia; Webb, Robert H.

    2016-01-01

    Question The decline and loss of perennial vegetation in dryland ecosystems due to global change pressures can alter ecosystem properties and initiate land degradation processes. We tracked changes of perennial vegetation using remote sensing to address the question of how prolonged drought and land-use intensification have affected perennial vegetation cover across a desert region in the early 21st century? Location Mojave Desert, southeastern California, southern Nevada, southwestern Utah and northwestern Arizona, USA. Methods We coupled the Moderate-Resolution Imaging Spectroradiometer Enhanced Vegetation Index (MODIS-EVI) with ground-based measurements of perennial vegetation cover taken in about 2000 and about 2010. Using the difference between these years, we determined perennial vegetation changes in the early 21st century and related these shifts to climate, soil and landscape properties, and patterns of land use. Results We found a good fit between MODIS-EVI and perennial vegetation cover (2000: R2 = 0.83 and 2010: R2 = 0.74). The southwestern, far southeastern and central Mojave Desert had large declines in perennial vegetation cover in the early 21st century, while the northeastern and southeastern portions of the desert had increases. These changes were explained by 10-yr precipitation anomalies, particularly in the cool season and during extreme dry or wet years. Areas heavily impacted by visitor use or wildfire lost perennial vegetation cover, and vegetation in protected areas increased to a greater degree than in unprotected areas. Conclusions We find that we can extrapolate previously documented declines of perennial plant cover to an entire desert, and demonstrate that prolonged water shortages coupled with land-use intensification create identifiable patterns of vegetation change in dryland regions.

  16. Investigating the Sustainability of Perennial Agriculture

    Science.gov (United States)

    Sutherlin, C. E.; Brunsell, N. A.; De Oliveira, G.; Crews, T.; Vico, G.

    2017-12-01

    The changing climate leads to uncertainties concerning the sustainability of certain agricultural resources, and with the additional stresses of an increasing global population, uncertainty in food security will greatly increase. To adhere to future food demands in the face of this changing climate, perennial agriculture has been a proposed solution. However, it is equally important to assure that perennial agriculture is not negatively affecting the climate in exchange for this proposed more robust food source. We chose to examine the interactions between perennial and annual agricultural crops by focusing on the efficiency of exchanges with the atmosphere. This is done using the omega decoupling factor for 4 different sites as a way of quantifying the contributions of radiation and stomatal conductance over the resulting water and carbon cycles. This gives us an indication of how the plant canopy is interacting with, and influencing the local microclimate. Ultimately, this should give us an indication of the ability of perennial crops to aid in the climate mitigation process. We hypothesized that the perennial site chosen would have omega values more similar to the omega values of a natural grassland rather than an annual crop site. Using AmeriFlux towers to determine the canopy values needed to calculate the omega decoupling factor, we focused on the Kernza perennial crops being grown at the Land Institute in Salina, Kansas (KLS), in comparison to a natural grassland in Manhattan, Kansas (KON), a typical land cover model in Lawrence, Kansas (KFS), and an annual crop site in Lamont, Oklahoma (ARM). These results will allow us to move forward in the investigation of perennial crops as a sustainable food source.

  17. Mapping the temporary and perennial character of whole river networks

    Science.gov (United States)

    González-Ferreras, A. M.; Barquín, J.

    2017-08-01

    Knowledge of the spatial distribution of temporary and perennial river channels in a whole catchment is important for effective integrated basin management and river biodiversity conservation. However, this information is usually not available or is incomplete. In this study, we present a statistically based methodology to classify river segments from a whole river network (Deva-Cares catchment, Northern Spain) as temporary or perennial. This method is based on an a priori classification of a subset of river segments as temporary or perennial, using field surveys and aerial images, and then running Random Forest models to predict classification membership for the rest of the river network. The independent variables and the river network were derived following a computer-based geospatial simulation of riverine landscapes. The model results show high values of overall accuracy, sensitivity, and specificity for the evaluation of the fitted model to the training and testing data set (≥0.9). The most important independent variables were catchment area, area occupied by broadleaf forest, minimum monthly precipitation in August, and average catchment elevation. The final map shows 7525 temporary river segments (1012.5 km) and 3731 perennial river segments (662.5 km). A subsequent validation of the mapping results using River Habitat Survey data and expert knowledge supported the validity of the proposed maps. We conclude that the proposed methodology is a valid method for mapping the limits of flow permanence that could substantially increase our understanding of the spatial links between terrestrial and aquatic interfaces, improving the research, management, and conservation of river biodiversity and functioning.

  18. Distribution of polycyclic aromatic hydrocarbons in subcellular root tissues of ryegrass (Lolium multiflorum Lam.)

    Science.gov (United States)

    2010-01-01

    Background Because of the increasing quantity and high toxicity to humans of polycyclic aromatic hydrocarbons (PAHs) in the environment, several bioremediation mechanisms and protocols have been investigated to restore PAH-contaminated sites. The transport of organic contaminants among plant cells via tissues and their partition in roots, stalks, and leaves resulting from transpiration and lipid content have been extensively investigated. However, information about PAH distributions in intracellular tissues is lacking, thus limiting the further development of a mechanism-based phytoremediation strategy to improve treatment efficiency. Results Pyrene exhibited higher uptake and was more recalcitrant to metabolism in ryegrass roots than was phenanthrene. The kinetic processes of uptake from ryegrass culture medium revealed that these two PAHs were first adsorbed onto root cell walls, and they then penetrated cell membranes and were distributed in intracellular organelle fractions. At the beginning of uptake (< 50 h), adsorption to cell walls dominated the subcellular partitioning of the PAHs. After 96 h of uptake, the subcellular partition of PAHs approached a stable state in the plant water system, with the proportion of PAH distributed in subcellular fractions being controlled by the lipid contents of each component. Phenanthrene and pyrene primarily accumulated in plant root cell walls and organelles, with about 45% of PAHs in each of these two fractions, and the remainder was retained in the dissolved fraction of the cells. Because of its higher lipophilicity, pyrene displayed greater accumulation factors in subcellular walls and organelle fractions than did phenanthrene. Conclusions Transpiration and the lipid content of root cell fractions are the main drivers of the subcellular partition of PAHs in roots. Initially, PAHs adsorb to plant cell walls, and they then gradually diffuse into subcellular fractions of tissues. The lipid content of intracellular

  19. Effect of application of fertilizer nitrogen, zinc and selenium on zinc nutrition of ryegrass

    International Nuclear Information System (INIS)

    Wei Dongpu; Bai Lingyu; Yao Yunyin; Hua Luo

    2001-01-01

    A pot experiment was carried out to study the effect of zinc or selenium fertilizer applied alone, combined application of nitrogen, zinc and selenium fertilizer on zinc nutrition of ryegrass in mono culture or in mixed culture in mountain yellow-brown earth of Hubei province. The results showed that: 1) Zn content was enhanced by mixed culture (white clover: ryegrass = 1:4), at the same time, Zn content of ryegrass in mixed culture was increased with increasing of Zn fertilizer. 2) The main reason of Zn content of ryegrass decreased in mixed culture was dilution effect due to the increase of dry weight. 3) In mono-Se treatment, Zn content of ryegrass in mixed culture was decreased with increasing of Se fertilizer. 4) In 9 treatment of combined applications of N, Zn and Se fertilizer, treatment of the highest Zn content of ryegrass in mixed culture was N46Zn25Se1; treatment of the highest Zn content of ryegrass in mono culture was N30Zn25Se5

  20. Annual ryegrass toxicity in Thoroughbred horses in Ceres in the Western Cape Province, South Africa

    Directory of Open Access Journals (Sweden)

    J.D. Grewar

    2009-05-01

    Full Text Available An outbreak of annual ryegrass toxicity occurred on a Thoroughbred stud in Ceres in the Western Cape Province of South Africa. This is the 1st report of annual ryegrass toxicity in horses in South Africa, although the condition has been reported in cattle and sheep populations in the past. Annual ryegrass toxicity is characterised by a variety of neurological signs including tremors, convulsions, recumbency and in many cases death. The description of the outbreak includes the history, clinical presentation and treatment protocol administered during the outbreak. Various epidemiological variables and their influence in the outbreak are also considered.

  1. Multiple resistance to glyphosate, paraquat and ACCase-inhibiting herbicides in Italian ryegrass populations from California: confirmation and mechanisms of resistance.

    Science.gov (United States)

    Tehranchian, Parsa; Nandula, Vijay; Jugulam, Mithila; Putta, Karthik; Jasieniuk, Marie

    2018-04-01

    Glyphosate, paraquat and acetyl CoA carboxylase (ACCase)-inhibiting herbicides are widely used in California annual and perennial cropping systems. Recently, glyphosate, paraquat, and ACCase- and acetolactate synthase (ALS)-inhibitor resistance was confirmed in several Italian ryegrass populations from the Central Valley of California. This research characterized the possible mechanisms of resistance. Multiple-resistant populations (MR1, MR2) are resistant to several herbicides from at least three modes of action. Dose-response experiments revealed that the MR1 population was 45.9-, 122.7- and 20.5-fold, and the MR2 population was 24.8-, 93.9- and 4.0-fold less susceptible to glyphosate, sethoxydim and paraquat, respectively, than the susceptible (Sus) population. Accumulation of shikimate in Sus plants was significantly greater than in MR plants 32 h after light pretreatments. Glyphosate resistance in MR plants was at least partially due to Pro106-to-Ala and Pro106-to-Thr substitutions at site 106 of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). EPSPS gene copy number and expression level were similar in plants from the Sus and MR populations. An Ile1781-to-Leu substitution in ACCase gene of MR plants conferred a high level of resistance to sethoxydim and cross-resistance to other ACCase-inhibitors. Radiolabeled herbicide studies and phosphorimaging indicated that MR plants had restricted translocation of 14 C-paraquat to untreated leaves compared to Sus plants. This study shows that multiple herbicide resistance in Italian ryegrass populations in California, USA, is due to both target-site and non-target-site resistance mechanisms. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. A generic model for estimating biomass accumulation and greenhouse gas emissions from perennial crops

    Science.gov (United States)

    Ledo, Alicia; Heathcote, Richard; Hastings, Astley; Smith, Pete; Hillier, Jonathan

    2017-04-01

    Agriculture is essential to maintain humankind but is, at the same time, a substantial emitter of greenhouse gas (GHG) emissions. With a rising global population, the need for agriculture to provide secure food and energy supply is one of the main human challenges. At the same time, it is the only sector which has significant potential for negative emissions through the sequestration of carbon and offsetting via supply of feedstock for energy production. Perennial crops accumulate carbon during their lifetime and enhance organic soil carbon increase via root senescence and decomposition. However, inconsistency in accounting for this stored biomass undermines efforts to assess the benefits of such cropping systems when applied at scale. A consequence of this exclusion is that efforts to manage this important carbon stock are neglected. Detailed information on carbon balance is crucial to identify the main processes responsible for greenhouse gas emissions in order to develop strategic mitigation programs. Perennial crops systems represent 30% in area of total global crop systems, a considerable amount to be ignored. Furthermore, they have a major standing both in the bioenergy and global food industries. In this study, we first present a generic model to calculate the carbon balance and GHGs emissions from perennial crops, covering both food and bioenergy crops. The model is composed of two simple process-based sub-models, to cover perennial grasses and other perennial woody plants. The first is a generic individual based sub-model (IBM) covering crops in which the yield is the fruit and the plant biomass is an unharvested residue. Trees, shrubs and climbers fall into this category. The second model is a generic area based sub-model (ABM) covering perennial grasses, in which the harvested part includes some of the plant parts in which the carbon storage is accounted. Most second generation perennial bioenergy crops fall into this category. Both generic sub

  3. Olivine weathering in soil, and its effects on growth and nutrient uptake in Ryegrass (Lolium perenne L.: a pot experiment.

    Directory of Open Access Journals (Sweden)

    Hein F M ten Berge

    Full Text Available Mineral carbonation of basic silicate minerals regulates atmospheric CO(2 on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO(2 sequestration ('enhanced weathering'. While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L., weathering during 32 weeks was inferred from bioavailability of magnesium (Mg in soil and plant. Olivine doses were equivalent to 1630 (OLIV1, 8150, 40700 and 204000 (OLIV4 kg ha(-1. Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6% and plant K concentration (+16.5% in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha(-1 (14.8% of dose, OLIV1 to 2240 kg ha(-1 (1.1%, OLIV4. This corresponds to gross CO(2 sequestration of 290 to 2690 kg ha(-1 (29 10(3 to 269 10(3 kg km(-2. Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the 'enhanced weathering' concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop.

  4. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input.

    Science.gov (United States)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman; Ambus, Per; Boelt, Birte; Gislum, René

    2016-01-15

    A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N fertilizer, the forage legume pure stand, especially red clover, was able to produce about 15 t above ground dry matter ha(-1) year(-1) saving around 325 kg mineral Nfertilizer ha(-1) compared to the cocksfoot and tall fescue grass treatments. The pure stand ryegrass yielded around 3t DM more than red clover in the high fertilizer treatment. Nitrous oxide emissions were highest in the treatments containing legumes. The LCA showed that the low input N systems had markedly lower carbon footprint values than crops from the high N input system with the pure stand legumes without N fertilization having the lowest carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground production across the three-season rotation, the pure stand red clover without N application and pure stand ryegrass treatments with the highest N input equalled. The present study illustrate how leguminous biological nitrogen fixation (BNF) represents an important low impact renewable N source without reducing crop yields and thereby farmers earnings. Copyright © 2015. Published by Elsevier B.V.

  5. Biosolids effectiveness to yield ryegrass based on their nitrogen content Eficiência de biossólidos na produção de azevém baseado no conteúdo de nitrogênio

    Directory of Open Access Journals (Sweden)

    Rodrigo Studart Corrêa

    2005-06-01

    Full Text Available Biosolids have been reported to increase yields and supply plant nutrients. However, complying with health and environmental standards is necessary before applying biosolids to land. Thus, sludge stabilization is required to make biosolids safe enough for their agricultural use. Side effects of stabilization processes on agronomic features of sewage sludge are not quite known, although their understanding is essential for biosolids management. Based on a model equivalent to the Mitscherlich equation, effects of the most common processes for sludge stabilization were evaluated (composting, liming, heat-drying and solar irradiation in relation to the agronomic effectiveness of biosolids to yield Lolium perenne L. on two tropical soils, with NH4H2PO4 as a reference. Sewage stabilization processes have affected the ability of biosolids to promote plant growth. Their effectiveness was usually higher than fertilizer in a Spodosol and lower in an Oxisol. Solar-irradiated sludge presented the highest effectiveness among the biosolids and reached peak yields at the lowest application rate independent on soil type. Biosolids could efficiently substitute fertilizers and even yield more plant dry matter than the NH4H2PO4 reference, depending on the biosolid and soil type.Biossólidos têm sido citados como capazes de aumentar a produção de culturas e suprir nutrientes para plantas. Questões sanitárias e ambientais demandam que eles sejam estabilizados para que sejam usados na agricultura. Os efeitos dos processos de estabilização sobre as propriedades agronômicas de biossólidos não são completamente conhecidos, apesar de essenciais para o seu manejo. Baseado em um modelo equivalente à equação de Mitscherlich, este trabalho avaliou os efeitos dos processos mais comuns para a estabilização de lodos de esgotos (compostagem, caleação, secagem térmica e irradiação solar sobre a eficiência agronômica de biossólidos na produção de Lolium

  6. Effect of aflatoxin B1 on in vitro ruminal fermentation of rations high in alfalfa hay or ryegrass hay

    DEFF Research Database (Denmark)

    Jiang, Y H; Yang, H J; Lund, Peter

    2012-01-01

    A 2 × 4 factorial experiment was conducted to determine the effect of aflatoxin B1 (AFB1) at dose rates of 0, 320, 640, 960 ng/ml on ruminal fermentation of substrates high in alfalfa hay (HA, alfalfa hay: maize meal = 4:1) and ryegrass hay (HR, ryegrass hay: maize meal = 4:1). In vitro dry matter...

  7. Direct control of perennial weeds between crops - Implication for organic farming

    DEFF Research Database (Denmark)

    Melander, Bo; Holst, Niels; Rasmussen, Ilse Ankjær

    2012-01-01

    and ending the strategy with mouldboard ploughing in the succeeding spring. Grain yields did not differ among the treatments in the two experiments as a result of the generally high effectiveness exerted by the control strategies. Especially post-harvest control strategies based on rotating weed devices...... and mouldboard ploughing appear to be effective solutions against mixed stands of perennials on sandy soils but they do not comply with optimal nutrient management in organic cropping. Therefore, intensive autumn cultivation is only relevant where a perennial weed problem is uncontrollable by other means.......Perennial weeds can be a major constraint to organic crop production and direct control actions applied between crops can then be necessary to reduce the problems. We conducted two experiments, one on a sandy loam and one on a sandy soil in Denmark, with the aim of studying the efficacy...

  8. Effects of soil microorganisms on uptake of 89Sr by ryegrass and bahia grass

    International Nuclear Information System (INIS)

    Zhong Weiliang; Liu Kexing

    2006-01-01

    In present study, 60 Co γ-rays was used to irradiate soil with doses of 3.0 kGy and 25.0 kGy, respectively, to discriminate between arbuscular mycorrhizal (AM) fungi and other soil microorganisms, while soil without irradiation was used as control to study the effects of soil microorganisms on uptake of 89 Sr by ryegrass and bahia grass. The results showed that the AM infection rates in ryegrass and bahia grass were 48.0% and 28.0% in the control soil, respectively which indicated that both grass species were prone to forming AM symbiosis with AM fungi. Although AM fungi and other soil microorganisms had no significant effect on above ground biomass in ryegrass and bahia grass, both AM fungi and other soil microorganisms decreased the uptake of 89 Sr in the two grass species, though to a more or less extant. (authors)

  9. Perennial Pepperweed Patches - San Francisco Estuary [ds295

    Data.gov (United States)

    California Natural Resource Agency — This layer contains polygon data for the perennial pepperweed (Lepidium latifolium) database. This database represents distribution data collected within the areas...

  10. Genomics: a potential panacea for the perennial problem.

    Science.gov (United States)

    McClure, Kendra A; Sawler, Jason; Gardner, Kyle M; Money, Daniel; Myles, Sean

    2014-10-01

    Perennial crops represent important fresh and processed food sources worldwide, but advancements in breeding perennials are often impeded due to their very nature. The perennial crops we rely on most for food take several years to reach production maturity and require large spaces to grow, which make breeding new cultivars costly compared with most annual crops. Because breeding perennials is inefficient and expensive, they are often grown in monocultures consisting of small numbers of elite cultivars that are vegetatively propagated for decades or even centuries. This practice puts many perennial crops at risk for calamity since they remain stationary in the face of evolving pest and disease pressures. Although there is tremendous genetic diversity available to them, perennial crop breeders often struggle to generate commercially successful cultivars in a timely and cost-effective manner because of the high costs of breeding. Moreover, consumers often expect the same cultivars to be available indefinitely, and there is often little or no incentive for growers and retailers to take the risk of adopting new cultivars. While genomics studies linking DNA variants to commercially important traits have been performed in diverse perennial crops, the translation of these studies into accelerated breeding of improved cultivars has been limited. Here we explain the "perennial problem" in detail and demonstrate how modern genomics tools can significantly improve the cost effectiveness of breeding perennial crops and thereby prevent crucial food sources from succumbing to the perils of perpetual propagation. © 2014 Botanical Society of America, Inc.

  11. Effect of soil parameters on uranium availability to ryegrass

    International Nuclear Information System (INIS)

    Vandenhove, H.; Van Hees, M.; Wannijn, J.; Wang, L.

    2004-01-01

    When wishing to assess the impact of radioactive contamination on biota or on an ecosystem, knowledge on the physico-chemical conditions governing the radionuclide availability and speciation in the exposure medium and hence its bioavailability and incorporation is indispensable. The present study explores the dominant soil factors (18 soils collected under pasture) ruling uranium mobility and availability to ryegrass and intents to define and assess the extent of the effect. The soils were selected such that they covered a wide range for those parameters hypothesized as being potentially important in determining U-availability (pH, clay content, Fe and Al oxide and hydroxide content, CaCO 3 , organic carbon). Statistical analysis showed that there were no single soil parameters significantly explaining the uranium concentration in the soil solution, nor the uranium concentration in the plants. Soil pH and iron-oxi-hydroxides explained for 60 % the uranium concentration found in the soil solution (which varied with factor 100). Plant U-concentration was mostly affected by the concentration of U in the soil solution, pH and total inorganic carbon content (R 2 =0.71). Observed U-uptake was highest when pH was below 5.3 or around 7 or higher. The next step was to assess the uranium speciation in the soil solution with a Geochemical Speciation Model. Uranium speciation was found important in explaining the U-uptake observed: apparently, uranyl, UO 2 CO 3 -2 and (UO 2 ) 2 CO 3 (OH) 3 - were the U-species being preferentially transported. (author)

  12. Anaerobic co-digestion of perennials: Methane potential and digestate nitrogen fertilizer value

    DEFF Research Database (Denmark)

    Muller-Stover, Dorette Sophie; Sun, Guotao; Kroff, Pablo

    2016-01-01

    Co-digestion of crop biomass improves the traditional manure-based biogas yield due to an increased content of easily degradable carbon compounds. In this study, the methane potential of three perennials (grass, legumes, and grass+legume) was determined using various amounts together with animal ...

  13. Teaching Writing: Some Perennial Questions and Some Possible Answers. Occasional Paper No. 85.

    Science.gov (United States)

    Florio-Ruane, Susan; Dunn, Saundra

    Based on the premise that writing research will be useful to educators only to the extent that it offers them conceptual tools to use in framing and solving their own problems, this paper reviews studies that address educators' perennial concerns about writing instruction. Among the questions addressed in the paper are those concerning (1) the…

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

    Science.gov (United States)

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

  15. Molecular basis of IgE-recognition of Lol p 5, a major allergen of rye-grass pollen.

    Science.gov (United States)

    Suphioglu, C; Blaher, B; Rolland, J M; McCluskey, J; Schäppi, G; Kenrick, J; Singh, M B; Knox, R B

    1998-04-01

    Grass pollen, especially of rye-grass (Lolium perenne). represents an important cause of type I allergy. Identification of IgE-binding (allergenic) epitopes of major grass pollen allergens is essential for understanding the molecular basis of interaction between allergens and human IgE antibodies and therefore facilitates the devising of safer and more effective diagnostic and immunotherapy reagents. The aim of this study was to identify the allergenic epitopes of Lol p 5, a major allergen of rye-grass pollen, immunodissect these epitopes further so that the amino acid residues critical for antibody binding can be determined and investigate the conservation and nature of these epitopes within the context of the natural grass pollen allergens. Peptides, 12-13 amino acid residues long and overlapping each other by 4 amino acid residues, based on the entire deduced amino acid sequence of the coding region of Lol p 5, were synthesised and assayed for IgE-binding. Two strong IgE-binding epitopes (Lol p 5 (49-60) and (265-276), referred to as peptides 7 and 34, respectively) were identified. These epitopes were further resolved by truncated peptides and amino acid replacement studies and the amino acid residues critical for IgE-binding determined (Lol p 5 (49-60) residue Lys57 and (265-276) residue Lys275). Sequences of these epitopes were conserved in related allergens and may form the conserved allergenic domains responsible for the cross-reactivity observed between pollen allergens of taxonomically related grasses. Furthermore, due to its strong IgE-reactivity, synthetic peptide Lol p 5 (265-276) was used to affinity-purify specific IgE antibodies which recognised proteins of other clinically important grass pollens. further indicating presence of allergenic cross-reactivity at the level of allergenic epitope. Moreover, Lol p 5 (265 276) demonstrated a strong capacity to inhibit IgE-binding to natural rye-grass pollen proteins highlighting the antibody accessibility

  16. Forage-based dairying in a water-limited future: use of models to investigate farming system adaptation in southern Australia.

    Science.gov (United States)

    Chapman, D F; Dassanayake, K; Hill, J O; Cullen, B R; Lane, N

    2012-07-01

    The irrigated dairy industry in southern Australia has experienced significant restrictions in irrigation water allocations since 2005, consistent with climate change impact predictions for the region. Simulation models of pasture growth (DairyMod), crop yield (Agricultural Production Systems Simulator, APSIM), and dairy system management and production (UDDER) were used in combination to investigate a range of forage options that may be capable of sustaining dairy business profitability under restricted water-allocation scenarios in northern Victoria, Australia. A total of 23 scenarios were simulated and compared with a base farm system (100% of historical water allocations, grazed perennial ryegrass pasture with supplements; estimated operating surplus $A2,615/ha at a milk price of $A4.14/kg of milk solids). Nine simulations explored the response of the base farm to changes in stocking rate or the implementation of a double cropping rotation on 30% of farm area, or both. Five simulations explored the extreme scenario of dairying without any irrigation water. Two general responses to water restrictions were investigated in a further 9 simulations. Annual ryegrass grazed pasture, complemented by a double cropping rotation (maize grown in summer for silage, followed by either brassica forage crop and annual ryegrass for silage in winter and spring) on 30% of farm area, led to an estimated operating surplus of $A1746/ha at the same stocking rate as the base farm when calving was moved to autumn (instead of late winter, as in the base system). Estimated total irrigation water use was 2.7ML/ha compared with 5.4ML/ha for the base system. Summer-dormant perennial grass plus double cropping (30% of farm area) lifted operating surplus by a further $A100/ha if associated with autumn calving (estimated total irrigation water use 3.1ML/ha). Large shifts in the forage base of dairy farms could sustain profitability in the face of lower, and fluctuating, water allocations

  17. Perennial Grass Bioenergy Cropping on Wet Marginal Land

    NARCIS (Netherlands)

    Das, Srabani; Teuffer, Karin; Stoof, Cathelijne R.; Walter, Michael F.; Walter, M.T.; Steenhuis, Tammo S.; Richards, Brian K.

    2018-01-01

    The control of soil moisture, vegetation type, and prior land use on soil health parameters of perennial grass cropping systems on marginal lands is not well known. A fallow wetness-prone marginal site in New York (USA) was converted to perennial grass bioenergy feedstock production. Quadruplicate

  18. Agroecology of Novel Annual and Perennial Crops for Biomass Production

    DEFF Research Database (Denmark)

    Manevski, Kiril; Jørgensen, Uffe; Lærke, Poul Erik

    The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production.......The agroecological potential of many crops under sustainable intensification has not been investigated. This study investigates such potential for novel annual and perennial crops grown for biomass production....

  19. Study on Effect of alfalfa, ryegrass and wheat middlings contents in ...

    African Journals Online (AJOL)

    微软用户

    2013-03-13

    Mar 13, 2013 ... 3Poultry Institute, Chinese Academy of Agricultural Sciences, Yangzhou, People's Republic of China. Accepted 16 ... The body weight (BW) of Group 3 geese was the biggest ... of alfalfa, ryegrass and wheat bran in diet in geese was 18%. .... images of tissues were taken using a Nikon Optiphot microscope.

  20. Anaerobic Digestion of Saline Creeping Wild Ryegrass for Biogas Production and Pretreatment of Particleboard Material

    Science.gov (United States)

    The objective of this research was to develop an integrated process to produce biogas and high-quality particleboard using saline creeping wild ryegrass (CWR), Leymus triticoides through anaerobic digestion (AD). Besides producing biogas, AD also serves as a pretreatment method to remove the wax la...

  1. Phytoremediation of high phosphorus soil by annual ryegrass and common bermudagrass harvest

    Science.gov (United States)

    Removal of soil phosphorus (P) in crop harvest is a remediation option for soils high in P. This four-year field-plot study determined P uptake by annual ryegrass (ARG, Lolium multiflorum Lam.) and common bermudagrass (CB, Cynodon dactylon (L.) Pers.) from Ruston soil (fine-loamy, siliceous, thermic...

  2. Arbuscular mycorrhizal fungi mediated uptake of 137Cs in leek and ryegrass

    International Nuclear Information System (INIS)

    Rosen, Klas; Weiliang, Zhong; Maertensson, Anna

    2005-01-01

    In a first experiment of soil contaminated with 137 Cs, inoculation with a mixture of arbuscular mycorrhizae enhanced the uptake of 137 Cs by leek under greenhouse conditions, while no effect on the uptake by ryegrass was observed. The mycorrhizal infection frequency in leek was independent of whether the 137 Cs-contaminated soil was inoculated with mycorrhizal spores or not. The lack of mycorrhizae-mediated uptake of 137 Cs in ryegrass could be due to the high root density, which was about four times that of leek, or due to a less well functioning mycorrhizal symbiosis than of leek. In a second experiment, ryegrass was grown for a period of four cuts. Additions of fungi enhanced 137 Cs uptake of all harvests, improved dry weight production in the first cut, and also improved the mycorrhizal infection frequencies in the roots. No differences were obtained between the two fungal inoculums investigated with respect to biomass production or 137 Cs uptake, but root colonization differed. We conclude that, under certain circumstances, mycorrhizae affect plant uptake of 137 Cs. There may be a potential for selecting fungal strains that stimulate 137 Cs accumulation in crops. The use of ryegrass seems to be rather ineffective for remediation of 137 Cs-contaminated soil

  3. Allelopathic interference of alfalfa (Medicago sativa L.) genotypes to annual ryegrass (Lolium rigidum).

    Science.gov (United States)

    Zubair, Hasan Muhammad; Pratley, James E; Sandral, G A; Humphries, A

    2017-07-01

    Alfalfa (Medicago sativa L.) genotypes at varying densities were investigated for allelopathic impact using annual ryegrass (Lolium rigidum) as the target species in a laboratory bioassay. Three densities (15, 30, and 50 seedlings/beaker) and 40 alfalfa genotypes were evaluated by the equal compartment agar method (ECAM). Alfalfa genotypes displayed a range of allelopathic interference in ryegrass seedlings, reducing root length from 5 to 65%. The growth of ryegrass decreased in response to increasing density of alfalfa seedlings. At the lowest density, Q75 and Titan9 were the least allelopathic genotypes. An overall inhibition index was calculated to rank each alfalfa genotype. Reduction in seed germination of annual ryegrass occurred in the presence of several alfalfa genotypes including Force 10, Haymaster7 and SARDI Five. A comprehensive metabolomic analysis using Quadruple Time of Flight (Q-TOF), was conducted to compare six alfalfa genotypes. Variation in chemical compounds was found between alfalfa root extracts and exudates and also between genotypes. Further individual compound assessments and quantitative study at greater chemical concentrations are needed to clarify the allelopathic activity. Considerable genetic variation exists among alfalfa genotypes for allelopathic activity creating the opportunity for its use in weed suppression through selection.

  4. Spring nitrogen fertilization of ryegrass-bermudagrass for phytoremediation of phosphorus-enriched soils

    Science.gov (United States)

    Nitrogen fertilization of forage grasses is critical for optimizing biomass and utilization of manure soil nutrients. Field studies were conducted in 2007-09 to determine the effects of spring N fertilization on amelioration of high soil P when cool-season, annual ryegrass (Lolium multiflorum L.) is...

  5. Plant growth-promoting Burkholderia species isolated from annual ryegrass in Portuguese soils.

    Science.gov (United States)

    Castanheira, N; Dourado, A C; Kruz, S; Alves, P I L; Delgado-Rodríguez, A I; Pais, I; Semedo, J; Scotti-Campos, P; Sánchez, C; Borges, N; Carvalho, G; Barreto Crespo, M T; Fareleira, P

    2016-03-01

    To search for culturable Burkholderia species associated with annual ryegrass in soils from natural pastures in Portugal, with plant growth-promoting effects. Annual ryegrass seedlings were used to trap Burkholderia from two different soils in laboratory conditions. A combined approach using genomic fingerprinting and sequencing of 16S rRNA and recA genes resulted in the identification of Burkholderia strains belonging to the species Burkholderia graminis, Burkholderia fungorum and the Burkholderia cepacia complex. Most strains were able to solubilize mineral phosphate and to synthesize indole acetic acid; some of them could produce siderophores and antagonize the phytopathogenic oomycete, Phytophthora cinnamomi. A strain (G2Bd5) of B. graminis was selected for gnotobiotic plant inoculation experiments. The main effects were the stimulation of root growth and enhancement of leaf lipid synthesis and turnover. Fluorescence in situ hybridization and confocal laser microscopy evidenced that strain G2Bd5 is a rhizospheric and endophytic colonizer of annual ryegrass. This work revealed that annual ryegrass can naturally associate with members of the genus Burkholderia. A novel plant growth promoting strain of B. graminis was obtained. The novel strain belongs to the plant-associated Burkholderia cluster and is a promising candidate for exploitation as plant inoculant in field conditions. © 2015 The Society for Applied Microbiology.

  6. Arbuscular mycorrhizal fungi mediated uptake of {sup 137}Cs in leek and ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, Klas; Weiliang, Zhong; Maertensson, Anna [Department of Soil Sciences, Swedish University of Agricultural Sciences P.O. Box 7014, SE-750 07 Uppsala (Sweden)

    2005-02-15

    In a first experiment of soil contaminated with {sup 137}Cs, inoculation with a mixture of arbuscular mycorrhizae enhanced the uptake of {sup 137}Cs by leek under greenhouse conditions, while no effect on the uptake by ryegrass was observed. The mycorrhizal infection frequency in leek was independent of whether the {sup 137}Cs-contaminated soil was inoculated with mycorrhizal spores or not. The lack of mycorrhizae-mediated uptake of {sup 137}Cs in ryegrass could be due to the high root density, which was about four times that of leek, or due to a less well functioning mycorrhizal symbiosis than of leek. In a second experiment, ryegrass was grown for a period of four cuts. Additions of fungi enhanced {sup 137}Cs uptake of all harvests, improved dry weight production in the first cut, and also improved the mycorrhizal infection frequencies in the roots. No differences were obtained between the two fungal inoculums investigated with respect to biomass production or {sup 137}Cs uptake, but root colonization differed. We conclude that, under certain circumstances, mycorrhizae affect plant uptake of {sup 137}Cs. There may be a potential for selecting fungal strains that stimulate {sup 137}Cs accumulation in crops. The use of ryegrass seems to be rather ineffective for remediation of {sup 137}Cs-contaminated soil.

  7. Bioenergy production from perennial energy crops: a consequential LCA of 12 bioenergy scenarios including land use changes.

    Science.gov (United States)

    Tonini, Davide; Hamelin, Lorie; Wenzel, Henrik; Astrup, Thomas

    2012-12-18

    In the endeavor of optimizing the sustainability of bioenergy production in Denmark, this consequential life cycle assessment (LCA) evaluated the environmental impacts associated with the production of heat and electricity from one hectare of Danish arable land cultivated with three perennial crops: ryegrass (Lolium perenne), willow (Salix viminalis) and Miscanthus giganteus. For each, four conversion pathways were assessed against a fossil fuel reference: (I) anaerobic co-digestion with manure, (II) gasification, (III) combustion in small-to-medium scale biomass combined heat and power (CHP) plants and IV) co-firing in large scale coal-fired CHP plants. Soil carbon changes, direct and indirect land use changes as well as uncertainty analysis (sensitivity, MonteCarlo) were included in the LCA. Results showed that global warming was the bottleneck impact, where only two scenarios, namely willow and Miscanthus co-firing, allowed for an improvement as compared with the reference (-82 and -45 t CO₂-eq. ha⁻¹, respectively). The indirect land use changes impact was quantified as 310 ± 170 t CO₂-eq. ha⁻¹, representing a paramount average of 41% of the induced greenhouse gas emissions. The uncertainty analysis confirmed the results robustness and highlighted the indirect land use changes uncertainty as the only uncertainty that can significantly change the outcome of the LCA results.

  8. Evaporite deposition in a shallow perennial lake, Qaidam basin, western China

    Energy Technology Data Exchange (ETDEWEB)

    Schubel, K.A.; Lowenstein, T.K. (SUNY, Binghampton, NY (United States)); Spencer, R.J. (Univ. of Calgary, Alberta (Canada)); Pengxi, Z. (Institute of Salt Lakes, Xining (China))

    1991-03-01

    Evaporites accumulate in ephemeral saline-pans, shallow perennial lakes or lagoons, and deep perennial systems. Continuous brine trench exposures of Holocene evaporites from the Qaidam basin provide criteria for the recognition of shallow perennial lake sediments. Based on Landsat photographs, lateral extent of beds (at least 7 km), and sequence thicknesses (maximum 2.5 m), the paleolake is interpreted to have been less than 2.5 m deep and at least 120 km{sup 2} in area. Sediments consist of laminated siliciclastic mud overlain by mud-halite couplets (mm- to cm-scale layers), which represent one vertical shallowing- and concentrating-upwards sequence. The basal laminite marks the onset of deposition in this shallow perennial paleolake. Syndepositional halite textures and fabrics in the overlying mud-halite couplets include cumulates, rafts, and chevrons, draped by mud laminae, and halite layers truncated by horizontal dissolution surfaces (increasing in frequency upwards). Paleolake brines, determined from fluid inclusion melting temperatures, are Na-Mg-Cl-rich and evolve from 0.84 m Mg{sup 2} to 1.52 m Mg{sup 2+} (near the surface). Combinations of the following criteria may be used for the recognition of shallow, nonstratified, perennial lake sediments: lateral continuity of layers; muds undisrupted by subaerial exposure; vertical bottom-growth of halite; halite layers conformably overlain by mud; halite layers truncated by nonuniformly spaced horizontal dissolution surfaces; erosional scours and channels filled with cross-laminated gypsum, halite, and siliciclastic sand and mud; and salinity fluctuations over small stratigraphic intervals within an overall concentrating-upwards sequence.

  9. Recycling of uranium by a perennial vegetation

    International Nuclear Information System (INIS)

    Thiry, Y.

    2005-01-01

    At sites of large scale mining and processing of uranium ore, tailings and waste rock piles are today the most visible relics of the uranium extractive industry. These mining relics are constantly subjected to weathering and leaching processes causing the dissemination of radioactive and toxic elements and sometimes requiring remedial operations. The in situ remediation of waste rock piles usually includes their revegetation for minimizing the water infiltration and for increasing surface soil stability. Thanks to its biomass density and longevity, the perennial vegetation plays an important role in stabilisation of the water cycling. The buffer role of forest vegetation can reduce water export from watersheds as well as erosion and hydrological losses of chemicals including radionuclides from contaminated sites. If long term reduction of contaminant dispersion at revegetated uranium mining sites is to be fully appreciated, then the extent of radioactive contaminant availability to forest vegetation and ecosystem cycling as well as the possible economic valorisation of the woody products must be considered. Concerned study focused on a Scots pine plantation established 35 years ago on a uranium waste rock pile (Wismuth GmbH) situated near Schlema (Germany). This investigation aimed at quantifying the mobility of uranium in the mining debris and its transport to the different tree compartments with emphasis on the processes involved. The influence of pine vegetation on uranium cycling dynamics was further assessed in terms of annual fluxes)

  10. A Gene Encoding a DUF247 Domain Protein Cosegregates with the S Self-Incompatibility Locus in Perennial Ryegrass

    DEFF Research Database (Denmark)

    Manzanares, Chloe; Barth, Susanne; Thorogood, Daniel

    2016-01-01

    genes cosegregating with the S-locus, a highly polymorphic gene encoding for a protein containing a DUF247 was fully predictive of known S-locus genotypes at the amino acid level in the seven mapping populations. Strikingly, this gene showed a frameshift mutation in self-compatible darnel (Lolium...

  11. The use of linear mixed models for analysis of repeated measurements applied to water-soluble carbohydrates in perennial ryegrass for seed production

    DEFF Research Database (Denmark)

    Gislum, René; Boelt, Birte; Zhang, Xia

    2009-01-01

    .) receiving different doses of growth regulators at different times. The objectives were to examine and compare three covariance structures and illustrate their effect on significance levels, the estimates, and standard error of estimates. The three covariance structures tested were unstructured, compound...

  12. Effect of timing and type of supplementary grain on herbage intake, nitrogen utilization and milk production in dairy cows grazed on perennial ryegrass pasture from evening to morning.

    Science.gov (United States)

    Ueda, Koichiro; Mitani, Tomohiro; Kondo, Seiji

    2017-01-01

    The present study aimed to clarify the effect of timing and type of supplementary grain in grazing dairy cows on herbage dry matter intake (HDMI), nitrogen utilization and milk production. Eight lactating cows were allowed to graze from evening to morning during three seasonal periods (spring, summer, autumn). They were randomly allocated to four treatments (timing: pre- (Pre) or post-grazing (Post), for large grain allotments consisting of 75% of daily grain offered; grain type: barley or corn) in 4 × 4 Latin square designs in each period. In the spring period, HDMI was greater for cows fed corn than those fed barley (P = 0.005), whereas cows in the Pre treatment had a similar HDMI, higher (P = 0.049) urinary purine derivative concentration and greater (P = 0.004) milk yield compared with cows in the Post treatment. In the summer and autumn periods, timing treatments did not affect HDMI, nitrogen utilization or milk production, but cows supplemented with barley had higher urinary purine derivatives concentration (P production without reducing HDMI regardless of grain type. © 2016 Japanese Society of Animal Science.

  13. Allium hookeri , Thw. Enum. A lesser known terrestrial perennial ...

    African Journals Online (AJOL)

    A lesser known terrestrial perennial herb used as food and its ethnobotanical ... from the wilderness, for consumption and traditional healing of various ailments. ... plants, the lifestyles of the people are changed and they prefer 'junk foods'.

  14. The Forecasting of Adaptation Potential of Herbaceous Perennials

    Directory of Open Access Journals (Sweden)

    Belykh, O. A.

    2013-04-01

    Full Text Available This work investigates the problem of the ecobiomorph productive features formation of perennial herbs Ranunculaceae family forecasting on the basis of quantitative connections of species parameters with the leading geomorphological factors of South Siberia environment.

  15. Bacterial endophytes of perennial crops for management of plant disease

    OpenAIRE

    Melnick, Rachel L.; Bailey, B.A.; Backman, Paul A.

    2013-01-01

    Metadata only record Bacterial endophytes, microorganisms which inhabit the internal tissues of plants, can suppress disease and are often used as a biological control in annual crops. Less research, however, has been applied to the use of bacterial endophytes to prevent disease in perennial crops, which presents a more complex challenge. However, exploration of their potential as a biological control in perennial crops has been limited. This chapter assembles current knowledge on the subj...

  16. Seed yield response to N fertilization and potential of proximal sensing in Italian ryegrass seed crops

    DEFF Research Database (Denmark)

    Vleugels, Tim; Rijckaert, Georges; Gislum, René

    2017-01-01

    Italian ryegrass (Lolium multiflorum L.) seed crops are often routinely fertilized with a predetermined amount of nitrogen (N) fertilizer in spring. However, nitrate leaching and increasing N fertilizer prices require rationalized fertilizer applications without compromises in seed yield....... The objectives of this study were (1) to determine the seed yield response to N fertilization, and (2) to evaluate if NDVI values can reliably predict the N status in Italian ryegrass seed crops. During eight years, field trials were conducted with two cultivars ‘Melclips’ and ‘Melquatro’, and seven N strategies...... applied after the forage cut as single or split application: 0, 60, 60 + 30, 90, 90 + 30, 120 and 150 kg N ha−1. NDVI values were obtained with a ‘GreenSeeker’ optical sensor. Maximum seed yield was attained at 141 kg N ha−1 total available N (92 kg N ha−1 fertilized). Higher fertilizations only increased...

  17. Distribution of copper and other elements in ryegrass roots, determined with a scanning proton microprobe

    International Nuclear Information System (INIS)

    Mazzolini, A.P.; Legge, G.J.F.

    1982-01-01

    A scanning proton microprobe has been used to determine the distribution of Cu and other elements in Wimmera ryegrass roots grown in solution cultures. Cu was found to be localized on or near the surface of the roots in randomly distributed discrete zones. The distribution of Cu was partially correlated with those of Fe, P and Ca and possibly indicates some form of association; co-precipitation in a precipitate of ferric phosphate or hydroxy-oxide is favoured

  18. Arbuscular mycorrhiza enhanced arsenic resistance of both white clover (Trifolium repens Linn.) and ryegrass (Lolium perenne L.) plants in an arsenic-contaminated soil

    International Nuclear Information System (INIS)

    Dong Yan; Zhu Yongguan; Smith, F. Andrew; Wang Youshan; Chen Baodong

    2008-01-01

    In a compartmented cultivation system, white clover (Trifolium repens Linn.) and ryegrass (Lolium perenne L.), with their roots freely intermingled, or separated by 37 μm nylon mesh or plastic board, were grown together in an arsenic (As) contaminated soil. The influence of AM inoculation on plant growth, As uptake, phosphorus (P) nutrition, and plant competitions were investigated. Results showed that both plant species highly depended on mycorrhizas for surviving the As contamination. Mycorrhizal inoculation substantially improved plant P nutrition, and in contrast markedly decreased root to shoot As translocation and shoot As concentrations. It also showed that mycorrhizas affected the competition between the two co-existing plant species, preferentially benefiting the clover plants in term of nutrient acquisition and biomass production. Based on the present study, the role of AM fungi in plant adaptation to As contamination, and their potential use for ecological restoration of As contaminated soils are discussed. - Both white clover and ryegrass highly depend on the mycorrhizal associations for surviving heavy arsenic contamination

  19. Arbuscular mycorrhiza enhanced arsenic resistance of both white clover (Trifolium repens Linn.) and ryegrass (Lolium perenne L.) plants in an arsenic-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Dong Yan; Zhu Yongguan [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Smith, F. Andrew [Soil and Land Systems, School of Earth and Environmental Sciences, Waite Campus, University of Adelaide, Adelaide, SA 5005 (Australia); Wang Youshan [Institute of Plant Nutrition and Resources, Beijing Academy of Agriculture and Forestry, Beijing 100089 (China); Chen Baodong [Department of Soil Environmental Science, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)], E-mail: bdchen@rcees.ac.cn

    2008-09-15

    In a compartmented cultivation system, white clover (Trifolium repens Linn.) and ryegrass (Lolium perenne L.), with their roots freely intermingled, or separated by 37 {mu}m nylon mesh or plastic board, were grown together in an arsenic (As) contaminated soil. The influence of AM inoculation on plant growth, As uptake, phosphorus (P) nutrition, and plant competitions were investigated. Results showed that both plant species highly depended on mycorrhizas for surviving the As contamination. Mycorrhizal inoculation substantially improved plant P nutrition, and in contrast markedly decreased root to shoot As translocation and shoot As concentrations. It also showed that mycorrhizas affected the competition between the two co-existing plant species, preferentially benefiting the clover plants in term of nutrient acquisition and biomass production. Based on the present study, the role of AM fungi in plant adaptation to As contamination, and their potential use for ecological restoration of As contaminated soils are discussed. - Both white clover and ryegrass highly depend on the mycorrhizal associations for surviving heavy arsenic contamination.

  20. In situ carbon and nitrogen dynamics in ryegrass-clover mixtures

    DEFF Research Database (Denmark)

    Rasmussen, J.; Eriksen, J.; Jensen, Erik Steen

    2007-01-01

    =9). 15N-enriched compounds were not detected in percolating pore water, which may be caused by either dilution from irrigation or low availability of leachable N compounds. 14C was found solely as 14CO2 in the pore water indicating that dissolved organic carbon (DOC) did not originate from fresh......Carbon (C) and nitrogen (N) dynamics in a third production year ryegrass–clover mixture were investigated in the field. Cylinders (diameter 29.7 cm) were installed to depths of 20, 40 and 60 cm and equipped with suction cups to collect percolating pore water. Ryegrass and clover leaves were cross......-labelled with 14C- and 15N-enriched urea and the fate of the two tracers was studied for 3 months during summer. Transfer of 14C occurred mainly from ryegrass to clover, whereas the largest transfer of 15N was in the opposite direction. The average transfer of N from clover was 40% (SE±3.1, n=9) of N in ryegrass...

  1. Concentrate supplementation strategies in ryegrass pasture for productive performance in lambs

    International Nuclear Information System (INIS)

    Santos, S.K.; Falbo, M.K.; Sandini, I.E.; Pacentchuk, F.; Neumann, M.; Garbossa, G.

    2018-01-01

    This study evaluated the effect of two concentrate supplementation strategies on performance, metabolic profile and economic evaluation of suckling lambs and ewes in ryegrass (Lolium multiflorum) pasture. Twenty-seven ewes and 45 lambs were divided into three groups: (1) ryegrass pasture without supplementation - control (CON); (2) CON plus supplemented ewes and lambs at 1% of live weight (SEL), and (3) CON plus creep feeding supplemented lambs at 1% of live weight (CSL). Concentrate use increased (p<0.05) average daily gain (ADG) by 19.95% over CON (21.6 and 18.3% for SEL and CSL, respectively). Concentrate use contributed to minimizing forage quality fluctuation and provided greater ADG stability, mainly when ryegrass nutritional content and digestibility decreased. Blood metabolites profiles did not differ between groups, with exception of phosphorus which was higher for CON than SEL, and calcium which was higher for CSL than CON (p<0.05). Compared to CON, stoking rate values were greater to SEL (p<0.05). Compared to CSL, ewe and total stocking rate were greater (p<0.05) to SEL. Considering the control group as break even feed investment, SEL strategy had a positive economic return, while CSL showed economic losses. Concentrate use increased ADG of lambs and decrease the impact of nutrient quality changes of forage on daily gains, but must be considered that supplemental strategy used could affect negatively economic return.

  2. Seasonal versus perennial immunotherapy: evaluation after three years of treatment.

    Science.gov (United States)

    Muñoz Lejarazu, D; Bernaola, G; Fernández, E; Audícana, M; Ventas, P; Martín, S; Fernández de Corres, L

    1993-01-01

    We have performed a comparative study to evaluate seasonal and perennial schedules after 3 years of immunotherapy. Sixty patients suffering from rhinitis and/or asthma due to grass pollen sensitization were randomly allocated to receive a semi-depot extract of Phleum pratense according to a perennial or seasonal schedule. The last year of the study, 14 patients were recruited as a control group without immunotherapy. The cumulative dose was 602 BU in the perennial group and 372 BU in the seasonal group. The frequency and severity of side-effects were similar and very low in both treated groups. The IgE level was significantly lower after perennial immunotherapy at the end of the first 2 years. A seasonal decrease in specific IgG levels was observed in patients who interrupted immunotherapy, while this was not observed in patients under the perennial schedule. Symptoms and medication scores did not show differences between groups. Nevertheless, we found a significant difference between treated patients and the control group.

  3. Totally impermeable film (TIF reduces emissions in perennial crop fumigation

    Directory of Open Access Journals (Sweden)

    Suduan Gao

    2013-10-01

    Full Text Available Many perennial nursery fields and replanted orchards and vineyards in California are treated with preplant soil fumigants to control soilborne pests. In annual crops, such as strawberry, covering fumigated fields with totally impermeable film (TIF has shown promise in controlling emissions and improving fumigant distribution in soil. The objective of this research was to optimize the use of TIF for perennial crops via three field trials. TIF reduced peak emission flux and cumulative emissions by > 90% relative to polyethylene tarp during a 2-week covering period. After the TIF was cut, emissions were greatly reduced compared to when tarps were cut after 6 days. TIF maintained higher fumigant concentrations under tarp and in the soil than polyethylene film. The results indicate that TIF can increase fumigation efficiency for perennial crop growers.

  4. Assessing Water-use Relationships in a Perennial Kernza Field

    Science.gov (United States)

    De Oliveira, G.; Brunsell, N. A.; Sutherlin, C. E.; Crews, T.; Vico, G.

    2017-12-01

    Perennial grain/forage crops can sustain high yields without replanting for 3-10 years or more, resulting in potentially important environmental benefits. Although previous research has been conducted in perennial food crops, the coupling between these ecosystems and the atmosphere is not well understood. The objective of this study was to evaluate the magnitude and temporal variability of the water-use relationships in a perennial Kernza wheatgrass crop in Salina, north-central region of Kansas (KS), USA. The study period comprised approximately 4.5 years (May 2012-October 2016) of eddy covariance observations collected at the US-KLS AmeriFlux tower. In particular, we examine the water-use efficiency, carbon and water fluxes in relation to the local environmental factors, such as vapor pressure deficit, soil moisture, air temperature, etc. An analysis of the correspondence between accumulated precipitation (PPT) and ET in the perennial crop indicated a most likely low surface runoff and that there were other sources of water for plant intake in addition to the annual PPT, i.e., deep water. In this sense, we highlight that the long roots observed in perennial crops may facilitate the water uptake in the deeper soil layers, providing extra resources for the plant growth especially when the rainfall indices are low. The results obtained in this work are important in order to better understand the hydrologic cycle of perennial agroecosystems as well as to understand the benefits and disadvantages in relation to annual crops particularly under changing climatic conditions.

  5. Identifying ephemeral and perennial stream reaches using apparent thermal inertia for an ungauged basin: The Rio Salado, Central New Mexico

    Science.gov (United States)

    Night and day temperature images from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) remote sensing images are used to identify ephemeral and perennial stream reaches for use in the calibration of an integrated hydrologic model of an ungauged basin. The concept is based on a...

  6. Comparative proteomic analyses reveal the proteome response to short-term drought in Italian ryegrass (Lolium multiflorum.

    Directory of Open Access Journals (Sweden)

    Ling Pan

    Full Text Available Drought is a major abiotic stress that impairs growth and productivity of Italian ryegrass. Comparative analysis of drought responsive proteins will provide insight into molecular mechanism in Lolium multiflorum drought tolerance. Using the iTRAQ-based approach, proteomic changes in tolerant and susceptible lines were examined in response to drought condition. A total of 950 differentially accumulated proteins was found to be involved in carbohydrate metabolism, amino acid metabolism, biosynthesis of secondary metabolites, and signal transduction pathway, such as β-D-xylosidase, β-D-glucan glucohydrolase, glycerate dehydrogenase, Cobalamin-independent methionine synthase, glutamine synthetase 1a, Farnesyl pyrophosphate synthase, diacylglycerol, and inositol 1, 4, 5-trisphosphate, which might contributed to enhance drought tolerance or adaption in Lolium multiflorum. Interestingly, the two specific metabolic pathways, arachidonic acid and inositol phosphate metabolism including differentially accumulated proteins, were observed only in the tolerant lines. Cysteine protease cathepsin B, Cysteine proteinase, lipid transfer protein and Aquaporin were observed as drought-regulated proteins participating in hydrolysis and transmembrane transport. The activities of phospholipid hydroperoxide glutathione peroxidase, peroxiredoxin, dehydroascorbate reductase, peroxisomal ascorbate peroxidase and monodehydroascorbate reductase associated with alleviating the accumulation of reactive oxygen species in stress inducing environments. Our results showed that drought-responsive proteins were closely related to metabolic processes including signal transduction, antioxidant defenses, hydrolysis, and transmembrane transport.

  7. Feasibility of Pb phytoextraction using nano-materials assisted ryegrass: Results of a one-year field-scale experiment.

    Science.gov (United States)

    Liang, Shu-Xuan; Jin, Yu; Liu, Wei; Li, Xiliang; Shen, Shi-Gang; Ding, Ling

    2017-04-01

    The effect of the combined application of nano-hydroxyapatite (NHAP) or nano-carbon black (NCB) on the phytoextraction of Pb by ryegrass was investigated as an enhanced remediation technique for soils by field-scale experiment. After the addition of 0.2% NHAP or NCB to the soil, temporal variation of the uptake of Pb in aboveground parts and roots were observed. Ryegrass shoot concentrations of Pb were lower with nano-materials application than without nano-materials for the first month. However, the shoot concentrations of Pb were significantly increased with nano-materials application, in particular NHAP groups. The ryegrass root concentrations of Pb were lower with nano-materials application for the first month. These results indicated that nano-materials had significant effects on stabilization of lead, especially at the beginning of the experiment. Along with the experimental proceeding, phytotoxicity was alleviated after the incorporation of nano-materials. The ryegrass biomass was significantly higher with nano-materials application. Consequently, the Pb phytoextraction potential of ryegrass significantly increased with nano-materials application compared to the gounps without nano-materials application. The total removal rates of soil Pb were higher after combined application of NHAP than NCB. NHAP is more suitable than NCB for in-situ remediation of Pb-contaminated soils. The ryegrass translocation factor exhibited a marked increase with time. It was thought that the major role of NHP and NBA might be to alleviate the Pb phytotoxicity and increase biomass of plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Defoliation effects of perennial grasses – continuing confusion | DL ...

    African Journals Online (AJOL)

    Although an adequate knowledge of growth patterns and defoliation effects in perennial grasses is a prerequisite for the rational use of veld and pastures for animal production, our knowledge of this subject is far from adequate. The results of various physiological and clipping studies on tropical and sub-tropical grasses are ...

  9. Rhetorical Transcendence Revisited: The "Thin Red Line" as Perennial Philosophy.

    Science.gov (United States)

    Stroud, Scott R.

    Fifteen years ago, J. H. Rushing published a seminal article addressing the fragmentation within contemporary society and the ways in which myths (films) may address this exigence. The exigence of fragmentation is relieved, according to her analysis, by mediated recourse to the perennial philosophy of monistic holism that is found across the…

  10. The occurrence of large branchiopod crustaceans in perennial pans ...

    African Journals Online (AJOL)

    Pans are isolated, shallow depressions that are endorheic in nature. Because of the natural hydrological functioning of pans, these systems are usually restricted to arid regions and complete desiccation occurs seasonally. In the eastern provinces of South Africa many pans are perennial in nature often remaining inundated ...

  11. Transgenic perennial biofuel feedstocks and strategies for bioconfinement

    Science.gov (United States)

    The use of transgenic tools for the improvement of plant feedstocks will be required to realize the full economic and environmental benefits of cellulosic and other biofuels, particularly from perennial plants. Traits that are targets for improvement of biofuels crops include he...

  12. Ionomics: Genes and QTLs controlling heavy metal uptake in perennial grasses grown on phytoxic soil

    Science.gov (United States)

    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...

  13. Diagnostics, taxonomy, nomenclature and distribution of perennial Sesuvium (Aizoaceae) in Africa

    Science.gov (United States)

    Sukhorukov, Alexander P.; Nilova, Maya V.; Erst, Andrey S.; Kushunina, Maria; Baider, Cláudia; Verloove, Filip; Salas-Pascual, Marcos; Belyaeva, Irina V.; Krinitsina, Anastasiya A.; Bruyns, Peter V.; Klak, Cornelia

    2018-01-01

    Abstract The taxonomy of perennial Sesuvium species in Africa has been poorly investigated until now. Previously five perennial species of Sesuvium were recognised in Africa (S. congense, S. crithmoides, S. mesembryanthemoides, S. portulacastrum, and S. sesuvioides). Based on the differing number of stamens, S. ayresii is accepted here as being distinct from S. portulacastrum. Field observations in Angola also led the authors to conclude that S. crystallinum and S. mesembryanthemoides are conspecific with S. crithmoides. A new subspecies, Sesuvium portulacastrum subsp. persoonii, is described from West Africa (Cape Verde, Gambia, Guinea-Bissau, Mauritania, Senegal). The molecular phylogeny indicates the position of S. portulacastrum subsp. persoonii within the “American lineage” as a part of the Sesuvium portulacastrum complex which needs further studies. A diagnostic key and taxonomic notes are provided for the six perennial species of Sesuvium found in Africa and recognised by the authors (S. ayresii, S. congense, S. crithmoides, S. portulacastrum subsp. portulacastrum, S. portulacastrum subsp. persoonii, S. verrucosum and the facultatively short-lived S. sesuvioides). The distribution of S. crithmoides, previously considered to be endemic to Angola, is now confirmed for the seashores of Republic of Congo and DR Congo. The American species S. verrucosum is reported for the first time for Africa (the Macaronesian islands: Cape Verde and the Canaries). It is locally naturalised in Gran Canaria, being a potentially invasive species. These findings as well as new records of S. verrucosum from Asia and the Pacific Islands confirm its proneness to transcontinental introduction. Lectotypes of S. brevifolium, S. crithmoides, S. crystallinum and S. mesembryanthemoides are selected. The seed micromorphology and anatomy of the perennial African species is studied. Compared to the seeds of some annual African Sesuvium investigated earlier, those of perennial species are

  14. Agronomic behavior of annual ryegrass (Lolium multiflorum lam. in Rio Grande do Sul State

    Directory of Open Access Journals (Sweden)

    I. F. Conterato

    2016-09-01

    Full Text Available The objective of this study was to evaluate forage production and number of days to flowering in 15 common ryegrass populations, one population of the KLM 138 (Uruguay and Fepagro São Gabriel cultivars, and one local population in order to select germplasm with production potential. A randomized block design consisting of three replicates and repeated measures over time (cuts was adopted. Forage production was evaluated by cutting samples of 2 linear meters per plot. The forage samples of each plot were dried and weighed for the determination of total dry matter. A total dry matter subsample of each plot, in each cut, was used to estimate leaf percentage. The data were submitted to analysis of variance using mixed models and means were compared by the Tukey test (P0.05, indicating little variability for this trait in the populations studied during the growth cycle. The populations differed significantly in terms of leaf dry matter percentage (P=0.0002. The highest leaf percentages during the growth cycle were observed for cultivar KLM 138. However, populations of the common Uruguayan, Dom Pedrito and Vacaria cultivars also exhibited good leaf production and may be used for initial selection of new promising materials, considering that a higher percentage of leaves promotes better quality feed offered to animals. The variation in the number of days to flowering permits selection for different maturation cycles of common ryegrass.

  15. Investigation the Kinetic Models of Biological Removal of Petroleum Contaminated Soil Around Oil Pipeline Using Ryegrass

    Directory of Open Access Journals (Sweden)

    Elham Ghaheri

    2014-04-01

    Full Text Available The industrial revolution of the past century has resulted in significant damage to environmental resources such as air, water and soil. Petroleum contamination of soil is a serious problem throughout the oil producer countries. Remediation of petroleum contamination of soils is generally a slow and expensive process. Phytoremediation is a potentially less-damaging, cost-effective, but needs longer-term for remediation of contaminated land compared to the alternative methods. In this study the kinetics of petroleum hydrocarbon contaminated soils in Khozestan were investigated. For this paper Ryegrass (Lolium perenne plant selected and the decline of total petroleum hydrocarbon (TPH was analyzed after growth stage, every 10 days up to 90 days. The results of TPH concentration was fitted with zero-order kinetic, first-order kinetic and Higuchi model. The result indicated that degradation of TPH with presence of plants as a function of time was well fitted with the first-order kinetic model. The first-order rate constants (K and half-lives (T1/2 for TPH degradation were 0.0098 1/day and 71 day; respectively. The results of phytoremediation showed that there were 65% decreases in TPH concentration with Ryegrass during the 17 weeks.

  16. Tritium forms discrimination in ryegrass under constant tritium exposure: From seed germination to seedling autotrophy.

    Science.gov (United States)

    Renard, H; Maro, D; Le Dizès, S; Escobar-Gutiérrez, A; Voiseux, C; Solier, L; Hébert, D; Rozet, M; Cossonnet, C; Barillot, R

    2017-10-01

    Uncertainties remain regarding the fate of atmospheric tritium after it has been assimilated in grasslands (ryegrass) in the form of TFWT (Tissue Free Water Tritium) or OBT (Organically Bound Tritium). One such uncertainty relates to the tritium forms discrimination during transfer from TFWT to OBT resulting from photosynthesis (OBT photo ), corresponding to the OBT photo /TFWT ratio. In this study, the OBT/TFWT ratio is determined by experiments in the laboratory using a ryegrass model and hydroponic cultures, with constant activity of tritium in the form of tritiated water (denoted as HTO) in the "water" compartment (liquid HTO) and "air" compartment (HTO vapour in the air). The OBT photo /TFWT ratio and the exchangeable OBT fraction are measured for three parts of the plant: the leaf, seed and root. Plant growth is modelled using dehydrated biomass measurements taken over time in the laboratory and integrating physiological functions of the plant during the first ten days after germination. The results suggest that there is no measurable discrimination of tritium in the plant organic matter produced by photosynthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. A Simulation Model of Mesophytic Perennial Grasslands Un Modelo de Simulación de Pradera Perenne Mesofítica

    Directory of Open Access Journals (Sweden)

    Giorgio Castellaro G

    2012-09-01

    Full Text Available Grasslands are complex ecosystems and their processes are affected by soil, meteorological, and management variables. In this context, dynamic simulation models are useful to understand these processes and to design grassland use strategies. The aim of this study was to develop and validate a simulation model of perennial pasture growth based on soil and climate variables. A first approach considered that soil fertility levels were adequate; therefore, soil water availability and phytomass level were the main variables affecting pasture growth. The subroutines considered were water balance, pasture growth, and root biomass dynamics. The hypotheses regarding the functioning of the system were formulated as a group of equations which were solved numerically with a program written in Visual Basic®. Model validation was performed by statistical comparison between simulated DM and DM obtained from experiments conducted in Valdivia (39°47' S., 73°15' W; 9 m a.s.l.. In these experiments we measured DM accumulation on naturalized grassland and ryegrass (Lolium perenne L.-white clover (Trifolium repens L. pastures under frequent defoliation. Soil data, temperature, solar radiation, and rainfall were obtained from a meteorological station located in Valdivia. The coefficient of determination between simulated values and those measured in the experiments were higher in the DM accumulation (R² = 98% simulations. When pasture was subjected to frequent defoliation, the degree of fit of the model was lower (R² = 60%; however, the model was able to predict the trend in the data.Los pastizales son ecosistemas complejos y sus procesos se ven afectados por variables edáficas, meteorológicas y de manejo. En este contexto, los modelos dinámicos de simulación son utiles para la comprensión de estos procesos y disenar estrategias de utilización de las praderas. El objetivo de este trabajo fue elaborar y validar un modelo de simulación de crecimiento de

  18. A study of the wet deposit and foliar uptake of iodine and strontium on rye-grass and clover

    International Nuclear Information System (INIS)

    Angeletti, Livio; Levi, Emilio; Commission of the European Communities, Ispra

    1977-12-01

    Foliar uptake of iodine and strontium by rye-grass and clover was studied as a function of aspersion intensities. At the same time, the contribution of root sorption to foliar uptake was measured. The effective half-lives of radionuclides of standing and harvested grass were also determined together with their uptake under the action of demineralized water aspersion [fr

  19. Preliminary studies on allelopatic effect of some woody plants on seed germination of rye-grass and tall fescue.

    Science.gov (United States)

    Arouiee, H; Nazdar, T; Mousavi, A

    2010-11-01

    In order to investigation of allelopathic effects of some ornamental trees on seed germination of rye-grass (Lolium prenne) and tall fescue (Festuca arundinaceae), this experiment was conducted in a randomized complete block design with 3 replicates at the laboratory of Horticultural Sciences Department of Ferdowsi University of Mashhad, during 2008. In this research, we studied the effect of aqueous and hydro-alcoholic extracts of Afghanistan pine (Pinus eldarica), arizona cypress (Cupressus arizonica), black locust (Robinia psedue acacia) and box elder (Acer negundo) leaves that prepared in 1:5 ratio on seed germination percent and rate for two grasses. The results showed that all extracts decreased statistically seed germination in compared to control treatment. The highest germination percentage and germination rate of tested grass detected in control treatment. Hydro-alcoholic extracts of all woody plants (15, 30%) were completely inhibited seed germination of rye-grass and tall fescue. Also aqueous extract of arizona cypress was completely inhibited seed germination of tall fescue and had more inhibitory activity than other aqueous extracts on rye-grass. Between aqueous extracts, the highest and lowest seed germination of rye-grass was found in Afghanistan pine and arizona cypress, respectively.

  20. Environmental life cycle assessments of producing maize, grass-clover, ryegrass and winter wheat straw for biorefinery

    DEFF Research Database (Denmark)

    Parajuli, Ranjan; Kristensen, Ib Sillebak; Knudsen, Marie Trydeman

    2017-01-01

    The aim of this study is to assess the potential environmental impacts of producing maize, grass-clover, ryegrass, and straw from winter wheat as biomass feedstocks for biorefinery. The Life Cycle Assessment (LCA) method included the following impact categories: Global Warming Potential (GWP100),...

  1. A comparative study of transfer factors of water, iodine and strontium on rye-grass and clover. Development of a model of evaluation of the limits of foliar contamination by wet deposit

    International Nuclear Information System (INIS)

    Angeletti, Livio; Levi, Emilio.

    1977-07-01

    Transfer factors of water, iodine ( 131 I) and strontium ( 85 Sr) on above-ground parts of rye-grass and clover were determined as a function of aspersion intensities. An analysis of the results showed the effect of aspersion intensities, nature of the chemical element and plant species on the values of transfer factors of iodine and strontium. It also made it possible to propose a simple method of evaluation of contamination limits of the aerial parts of plants by wet deposit, based on transfer values of water on plants only [fr

  2. Review of literature on perennial peanut (Arachis pintoi) as potential cover crop in the tropics

    OpenAIRE

    Kartika, J.G.; Reyes, Manuel R.; Susila, Anas D.

    2007-01-01

    The use of living mulch as a substitute for plastic mulch is increasing in the tropics as researchers have gradually shifted their attention to organic farming systems. Arachis pintoi is a perennial plant and a member of the leguminosae family. A. pintoi has good potential for use as a living mulch in association with vegetables, trees, or grass (as a pasture) because of its ability to fix nitrogen from the atmosphere and to grow in heavy shade. This work, based on fact sheets, journals and t...

  3. Dinosaur demise in light of their alleged perennial polar residency

    Science.gov (United States)

    Lewy, Zeev

    2017-10-01

    The end-Cretaceous biological crisis is represented by the demise of the non-avian dinosaurs. However, most crucial biologically was the elimination of the photosynthesizing marine phyto- and zooplankton forming the base of the marine food chain. Their abrupt demise attests to sunlight screening darkening the atmosphere for a few years. Alvarez et al. (Science 208:1095-1108, 1980. doi: 10.1126/science.208.44) noticed in deep marine end-Cretaceous sediments an anomalous rise in the chemical element iridium (Ir), which is rare on planet Earth and thus suggests an extraterrestrial origin through an impact of a large asteroid. This impact would have ejected enormous quantities of particles and aerosols, shading the solar illumination as attested to by the elimination of the marine photosynthesizing plankton. Such a dark period must have affected life on land. The apparent cold-blooded non-avian dinosaurs, which were used to living in open terrains to absorb the solar illumination, became inactive during the dark period and were incapable of withstanding predators. This was in contrast to cold-blooded crocodilians, turtles and lizards that could hide in refuge sites on land and in the water. Dinosaur relics discovered in Cretaceous Polar Regions were attributed to perennial residents, surviving the nearly half-year-long dark winter despite their ability to leave. The polar concentrations of disarticulated dinosaur bones were suggested as having resulted from a catastrophic burial of a population by floods. However, this should have fossilized complete skeletons. Alternatively, herds of dinosaurs living in high latitudes might have been sexually driven to spend the half year of continuously illuminated polar summer for mating rather than for nourishment, in which the lower latitudes provided as well. The aggressive mating competitions would have left victims among the rivals and of young ones incidentally trampled over, all being consumed and their skeletons

  4. Medium-term response of microbial community to rhizodeposits of white clover and ryegrass and tracing of active processes induced by 13C and 15N labelled exudates

    DEFF Research Database (Denmark)

    Kusliene, Gedrime; Rasmussen, Jim; Kuzyakov, Yakov

    2014-01-01

    and actinomycetes was unaffected by plant species, but pool of Gram-negative and Gram-positive bacteria was greater under white clover at the 10 percent significance level. In the short term, microorganisms more actively utilised fresh exudates (13C-labelled) of ryegrass than of white clover. We expected ryegrass...... microbial groups in soil under white clover (Trifolium repens L.) and ryegrass (Lolium perenne L.) following leaf-labelling with 13C-bicarbonate and 15N-urea. In this way microbial N and 15N and the composition of PLFAs reflect the medium-term (two months) response of microorganisms to rhizodeposits......, whereas the 13C-label of the PLFAs reflects the short-term (one week) utilisation of root exudates following labelling of shoots. In the medium term, microbial biomass N and 15N were greater under the ryegrass, whereas total PLFA was higher under white clover. The relative abundance of fungi...

  5. Effects of biochars on the availability of heavy metals to ryegrass in an alkaline contaminated soil.

    Science.gov (United States)

    Zhang, Guixiang; Guo, Xiaofang; Zhao, Zhihua; He, Qiusheng; Wang, Shuifeng; Zhu, Yuen; Yan, Yulong; Liu, Xitao; Sun, Ke; Zhao, Ye; Qian, Tianwei

    2016-11-01

    A pot experiment was conducted to investigate the effects of biochars on the availability of heavy metals (Cd, Cu, Mn, Ni, Pb, and Zn) to ryegrass in an alkaline contaminated soil. Biochars only slightly decreased or even increased the availability of heavy metals assesses by chemical extractant (a mixture of 0.05 mol L -1 ethylenediaminetetraacetic acid disodium, 0.01 mol L -1 CaCl 2 , and 0.1 mol L -1 triethanolamine). The significantly positive correlation between most chemical-extractable heavy metals and the ash content in biochars indicated the positive role of ash in this extraction. Biochars significantly reduced the plant uptake of heavy metals, excluding Mn. The absence of a positive correlation between the chemical-extractable heavy metals and the plant uptake counterparts (except for Mn) indicates that chemical extractability is probably not a reliable indicator to predict the phytoavailability of most heavy metals in alkaline soils treated with biochars. The obviously negative correlation between the plant uptake of heavy metals (except for Mn) and the (O + N)/C and H/C indicates that biochars with more polar groups, which were produced at lower temperatures, had higher efficiency for reducing the phytoavailability of heavy metals. The significantly negative correlations between the plant uptake of Mn and ryegrass biomass indicated the "dilution effect" caused by the improvement of biomass. These observations will be helpful for designing biochars as soil amendments to reduce the availability of heavy metals to plants in soils, especially in alkaline soils. Copyright © 2016. Published by Elsevier Ltd.

  6. Allergenic fragments of ryegrass (Lolium perenne) pollen allergen Lol p IV.

    Science.gov (United States)

    Jaggi, K S; Ekramoddoullah, A K; Kisil, F T

    1989-01-01

    To facilitate studies on establishing the nature of structure/function relationships of allergens, ryegrass pollen allergen, Lol p IV, was cleaved into smaller fragments by cyanogen bromide (CNBr) and the resulting peptides were further digested with trypsin. The resulting peptides were then fractionated by high performance liquid chromatography (HPLC) on a C-18 reverse phase column. The allergenic activity of the HPLC fractions was evaluated in terms of their ability to inhibit the binding of 125I-Lol p IV to serum IgE antibodies of a grass-allergic patient. Many of these fractions inhibited the binding between the native allergen and IgE antibodies in a dose-dependent manner. The inhibitions were specific, i.e., the fractions did not inhibit the binding between 125I-Lol p I (a group-I ryegrass pollen allergen) and the IgE antibodies present in the allergic human serum. The possibility that the allergenic peptide fractions were contaminated by the native undegraded allergen, which might have accounted for the observed inhibition, was ruled out by the fact that the native allergen could not be detected by SDS-PAGE and the elution profiles of allergenically active peptides did not coincide with that of native allergen. One of the allergenic sites recognized by monoclonal antibody (Mab) 90, i.e., site A, was located in HPLC fractions 90-100 while another allergenic site B (recognized by Mab 12) appeared to be lost following the sequential digestion of Lol p IV with CNBr and trypsin.

  7. Behavior pattern of beef heifers supplemented with different energy sources on oat and ryegrass pasture

    Directory of Open Access Journals (Sweden)

    Luiz Angelo Damian Pizzuti

    2012-08-01

    Full Text Available The objective of this study was to evaluate behavior patterns of heifers grazing on black oat (Avena strigosa Schreb. and ryegrass (Lolium multiflorum Lam., fed supplementation with brown rice meal and/or protected fat. A total of 28 Charolais × Nellore crossbred heifers at average initial age of 18 months and with initial live weight of 274.9±4.97 kg were used in the experiment. Animals were kept in oat + ryegrass pastures and distributed in the following treatments: no supplementation; Megalac (MEG: protected fat supplementation; supplementation with brown rice meal (BRM; and supplementation with BRM + MEG. The neutral detergent fiber (NDF intake of pasture either in kg or in percentage of live weight was not changed by supply of supplement, but increased linearly (0.045 kg per day over grazing periods. Supplementation with BRM and BRM + MEG reduced grazing time, 49.63%, in relation to non-supplemented animals and animals supplemented with MEG, 63.13%. Feeding seasons per minute increased over the experimental period with reduction in time spent in each feeding station. The number of bites per feeding station decreased linearly, with a variation of 34.48% in the late grazing period. Heifers supplemented with BRM and BRM + MEG require less time for grazing and increase their idle time, with no modification in displacement patterns within the paddocks and pasture ingestion. Grazing and idle time does not change in the distinct periods of pasture use, but rumination time increases with days of pasture use and with increase in NDF intake.

  8. Phytoextraction of metals and rhizoremediation of PAHs in co-contaminated soil by co-planting of Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis).

    Science.gov (United States)

    Wang, Kai; Huang, Huagang; Zhu, Zhiqiang; Li, Tingqiang; He, Zhenli; Yang, Xiaoe; Alva, Ashok

    2013-01-01

    A pot experiment was conducted to investigate the potential for phytoextraction of heavy metals and rhizoremediation of polycyclic aromatic hydrocarbons (PAHs) in co-contaminated soil by co-planting a cadmium/zinc (Cd/Zn) hyperaccumulator and lead (Pb) accumulator Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis). Co-planting with castor decreased the shoot biomass of S. alfredii as compared to that in monoculture. Cadmium concentration in S. alfredii shoot significantly decreased when grown with ryegrass or castor as compared to that in monoculture. However, no reduction of Zn or Pb concentration in S. alfredii shoot was detected in co-planting treatments. Total removal of either Cd, Zn, or Pb by plants was similar across S. alfredii monoculture or co-planting with ryegrass or castor, except enhanced Pb removal in S. alfredii and ryegrass co-planting treatment. Co-planting of S. alfredii with ryegrass or castor significantly enhanced the pyrene and anthracene dissipation as compared to that in the bare soil or S. alfredii monoculture. This appears to be due to the increased soil microbial population and activities in both co-planting treatments. Co-planting of S. alfredii with ryegrass or castor provides a promising strategy to mitigate both metal and PAH contaminants from co-contaminated soils.

  9. Energizing marginal soils: A perennial cropping system for Sida hermaphrodita

    Science.gov (United States)

    Nabel, Moritz; Poorter, Hendrik; Temperton, Vicky; Schrey, Silvia D.; Koller, Robert; Schurr, Ulrich; Jablonowski, Nicolai D.

    2017-04-01

    As a way to avoid land use conflicts, the use of marginal soils for the production of plant biomass can be a sustainable alternative to conventional biomass production (e.g. maize). However, new cropping strategies have to be found that meet the challenge of crop production under marginal soil conditions. We aim for increased soil fertility by the use of the perennial crop Sida hermaphrodita in combination with organic fertilization and legume intercropping to produce substantial biomass yield. We present results of a three-year outdoor mesocosm experiment testing the perennial energy crop Sida hermaphrodita grown on a marginal model substrate (sand) with four kinds of fertilization (Digestate broadcast, Digestate Depot, mineral NPK and unfertilized control) in combination with legume intercropping. After three years, organic fertilization (via biogas digestate) compared to mineral fertilization (NPK), reduced the nitrate concentration in leachate and increased the soil carbon content. Biomass yields of Sida were 25% higher when fertilized organically, compared to mineral fertilizer. In general, digestate broadcast application reduced root growth and the wettability of the sandy substrate. However, when digestate was applied locally as depot to the rhizosphere, root growth increased and the wettability of the sandy substrate was preserved. Depot fertilization increased biomass yield by 10% compared to digestate broadcast fertilization. We intercropped Sida with various legumes (Trifolium repens, Trifolium pratense, Melilotus spp. and Medicago sativa) to enable biological nitrogen fixation and make the cropping system independent from synthetically produced fertilizers. We could show that Medicago sativa grown on marginal substrate fixed large amounts of N, especially when fertilized organically, whereas mineral fertilization suppressed biological nitrogen fixation. We conclude that the perennial energy crop Sida in combination with organic fertilization has great

  10. Reproduction and recruitment in perennial colonies of the introduced wasp Vespula germanica.

    Science.gov (United States)

    Goodisman, M A; Matthews, R W; Spradbery, J P; Carew, M E; Crozier, R H

    2001-01-01

    We investigated the genetic structure of perennial colonies of the yellowjacket wasp (Vespula germanica) in its introduced range in Australia and New Zealand. The nuclear genotypes of 712 gynes from 21 colonies, 147 workers from 5 colonies, and 81 males from 4 colonies were assayed at three polymorphic microsatellite loci. The mitochondrial haplotypes of all wasps also were determined for a 450-bp region of the mtDNA using double-stranded conformational polymorphism (DSCP) analysis. We found that multiple reproductives were needed to explain the genotypes of gynes, workers, and males in 7 of 21, 2 of 5, and 2 of 4 colonies, respectively, and that nestmate relatedness of these three castes equaled 0.42, 0.16, and 0.22, respectively. The mitochondrial data revealed that all individuals shared the same mtDNA haplotype in 20 of the 21 colonies. However, in one colony, gynes and workers displayed multiple mtDNA haplotypes, indicating that nonnestmate recruitment had occurred. Overall the genetic structure within the majority of perennial colonies conformed to expectations based on the biology of V. germanica and kin selection theory for polygyne colonies; multiple reproductives successfully produced offspring and were recruited into their natal nests, thereby maintaining relatively high relatedness between interacting individuals.

  11. Seasonal variations of cadmium and zinc in Arrhenatherum elatius, a perennial grass species from highly contaminated soils

    International Nuclear Information System (INIS)

    Deram, Annabelle; Denayer, Franck-Olivier; Petit, Daniel; Van Haluwyn, Chantal

    2006-01-01

    There is interest in studying bioaccumulation in plants because they form the base of the food chain as well as their potential use in phytoextraction. From this viewpoint, our study deals with the seasonal variation, from January to July, of Cd and Zn bioaccumulation in three metallicolous populations of Arrhenatherum elatius, a perennial grass with a high biomass production. In heavily polluted soils, while Zn bioaccumulation is weak, A. elatius accumulates more Cd than reported gramineous plants, with concentration of up to 100 μg g -1 . Our results also showed seasonal variations of bioaccumulation, underlying the necessity for in situ studies to specify the date of sampling and also the phenology of the collected plant sample. In our experimental conditions, accumulation is lower in June, leading us to the hypothesis of restriction in heavy metals translocation from roots to aerial parts during seed production. - Cd and Zn bioaccumulation varies seasonally in a perennial grass

  12. Seasonal variations of cadmium and zinc in Arrhenatherum elatius, a perennial grass species from highly contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Deram, Annabelle [Institut Lillois d' Ingenierie de la Sante, Universite Droit et Sante de Lille, EA 2690, 42 rue Ambroise Pare, 59120 Loos (France)]. E-mail: aderam@ilis.univ-lille2.fr; Denayer, Franck-Olivier [Institut Lillois d' Ingenierie de la Sante, Universite Droit et Sante de Lille, EA 2690, 42 rue Ambroise Pare, 59120 Loos (France); Petit, Daniel [Laboratoire de Genetique et Evolution des Populations Vegetales, UPRESA-CNRS 8016, Bat SN2, Universite des Sciences et Techniques de Lille, 59655 Villeneuve d' Ascq, F59655 France (France); Van Haluwyn, Chantal [Faculte des Sciences Pharmaceutiques et Biologiques, Departement de Botanique, Universite Droit et Sante de Lille, EA 2690, B.P. 83, 59006 Lille Cedex (France)

    2006-03-15

    There is interest in studying bioaccumulation in plants because they form the base of the food chain as well as their potential use in phytoextraction. From this viewpoint, our study deals with the seasonal variation, from January to July, of Cd and Zn bioaccumulation in three metallicolous populations of Arrhenatherum elatius, a perennial grass with a high biomass production. In heavily polluted soils, while Zn bioaccumulation is weak, A. elatius accumulates more Cd than reported gramineous plants, with concentration of up to 100 {mu}g g{sup -1}. Our results also showed seasonal variations of bioaccumulation, underlying the necessity for in situ studies to specify the date of sampling and also the phenology of the collected plant sample. In our experimental conditions, accumulation is lower in June, leading us to the hypothesis of restriction in heavy metals translocation from roots to aerial parts during seed production. - Cd and Zn bioaccumulation varies seasonally in a perennial grass.

  13. Enzymatic production of wheat and ryegrass derived xylooligosaccharides and evaluation of their in vitro effect on pig gut microbiota

    DEFF Research Database (Denmark)

    Dotsenko, Gleb; Meyer, Anne S.; Canibe, Nuria

    2017-01-01

    This study examines enzymatic production of linear xylooligosaccharides (XOS) and branched arabinoxylooligosaccharides (AXOS) from monocotyledonous biomass, wheat straw and ryegrass, and compares the in vitro effects of these XOS and AXOS on pig gut microbiota. XOS and AXOS were obtained from...... the biomass by treatment with different endo-1,4-β-xylanases. XOS of DP2-6 from wheat straw, obtained after treatment with Aspergillus niger endo GH11, suppressed growth of Clostridium perfringens and resulted in a high level of lactic acid production when fermented in vitro by pig fecal microbiota...... (GH11). These results indicate that wheat straw as well as green grass biomass such as ryegrass have potential as new sources of putative prebiotics for pig feed....

  14. Tradeoffs between water requirements and yield stability in annual vs. perennial crops

    Science.gov (United States)

    Vico, Giulia; Brunsell, Nathaniel A.

    2018-02-01

    Population growth and changes in climate and diets will likely further increase the pressure on agriculture and water resources globally. Currently, staple crops are obtained from annuals plants. A shift towards perennial crops may enhance many ecosystem services, but at the cost of higher water requirements and lower yields. It is still unclear when the advantages of perennial crops overcome their disadvantages and perennial crops are thus a sustainable solution. Here we combine a probabilistic description of the soil water balance and crop development with an extensive dataset of traits of congeneric annuals and perennials to identify the conditions for which perennial crops are more viable than annual ones with reference to yield, yield stability, and effective use of water. We show that the larger and more developed roots of perennial crops allow a better exploitation of soil water resources and a reduction of yield variability with respect to annual species, but their yields remain lower when considering grain crops. Furthermore, perennial crops have higher and more variable irrigation requirements and lower water productivity. These results are important to understand the potential consequences for yield, its stability, and water resource use of a shift from annual to perennial crops and, more generally, if perennial crops may be more resilient than annual crops in the face of climatic fluctuations.

  15. Behavior of decabromodiphenyl ether (BDE-209) in soil: Effects of rhizosphere and mycorrhizal colonization of ryegrass roots

    Energy Technology Data Exchange (ETDEWEB)

    Wang Sen [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Zhang Shuzhen, E-mail: szzhang@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Huang, Honglin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Christie, Peter [Agri-Environment Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom)

    2011-03-15

    A rhizobox experiment was conducted to investigate degradation of decabromodiphenyl ether (BDE-209) in the rhizosphere of ryegrass and the influence of root colonization with an arbuscular mycorrhizal (AM) fungus. BDE-209 dissipation in soil varied with its proximity to the roots and was enhanced by AM inoculation. A negative correlation (P < 0.001, R{sup 2} = 0.66) was found between the residual BDE-209 concentration in soil and soil microbial biomass estimated as the total phospholipid fatty acids, suggesting a contribution of microbial degradation to BDE-209 dissipation. Twelve and twenty-four lower brominated PBDEs were detected in soil and plant samples, respectively, with a higher proportion of di- through hepta-BDE congeners in the plant tissues than in the soils, indicating the occurrence of BDE-209 debromination in the soil-plant system. AM inoculation increased the levels of lower brominated PBDEs in ryegrass. These results provide important information about the behavior of BDE-209 in the soil-plant system. - Research highlights: > BDE-209 dissipation in soil was affected by the proximity to the roots. > Microbial degradation contributes greatly to BDE-209 dissipation in the soil. > Twelve and twenty-four lower brominated PBDEs were detected in soil and plant samples. > AM inoculation increased root uptake and accumulation of BDE-209. - BDE-209 dissipation and degradation in soil were affected by both its proximity to ryegrass roots and inoculation with an AM fungus.

  16. Effects of seeding ryegrass (Lolium multiflorum) on vegetation recovery following fire in a ponderosa pine (Pinus ponderosa) forest

    Science.gov (United States)

    Barclay, Angela D.; Betancourt, Julio L.; Allen, Craig D.

    2004-01-01

    Forty-nine vegetation transects were measured in 1997 and 1998 to determine the impact of grass seeding after the 1996 Dome Fire, which burned almost 6900 ha of ponderosa pine (Pinus ponderosa Lawson) forest in the Jemez Mountains of north-central New Mexico. High- and moderate-burned areas in Santa Fe National Forest were seeded with a mixture that included the exotic ryegrass (Lolium multiflorum Lam.). Adjacent burned areas of Bandelier National Monument were not seeded, and were used as a control in the post-seeding study. On the seeded plots, foliar cover of ryegrass declined from 1997 to 1998 due to self-inhibition and/or reduced precipitation from 1997 to 1998. Foliar cover and diversity of native forbs were greater in 1997 than 1998, probably due to a wet growing season in 1997. Cover, species richness, and diversity of native forbs were highest in non-seeded areas of moderate- and high-burn intensities. Regeneration and survivorship of conifer seedlings decreased as ryegrass cover increased, particularly in areas of high-burn intensity. Exotic plant cover, mostly horseweed [Conyza canadensis (L.) Cronq.], increased from 1997 to 1998 in non-seeded areas of moderate- and high-burn intensity. Both the initial success of seeding and the eventual impacts on native vegetation were strongly modulated by climate variability.

  17. Arsenic extractability and uptake by velvetgrass Holcus lanatus and ryegrass Lolium perenne in variously treated soils polluted by tailing spills.

    Science.gov (United States)

    Karczewska, Anna; Lewińska, Karolina; Gałka, Bernard

    2013-11-15

    Phytostabilization should be considered as an appropriate phytoremediation technique to restore the area affected by tailing spills in Zloty Stok, where arsenic ores were mined and processed for several centuries. The study aimed to compare the suitability of velvetgrass (Holcus lanatus L.) and ryegrass (Lolium perenne L.) for development of plant cover in that area. Various treatments commonly applied to support phytostabilization were examined. A pot experiment was carried out to assess the effects of soil amendment with phosphate (P), sewage sludge (SS) and iron salts (Fe) on arsenic extractability and its uptake by grass. Four kinds of soil material, containing 356-5350 mg kg(-1) As, were examined. Velvetgrass proved to be more resistant than ryegrass to the toxicity of soil arsenic. Ammonium sulphate extractability of As in soils correlated well with As concentrations in the biomass of both grass species. In three of four tested soils, application of Fe failed to decrease As extractability and to reduce its concentrations in the aboveground parts of grasses. Application of P and SS resulted in increased As solubility in soils, but their effects on plant biomass and As uptake were ambiguous. SS had a strong beneficial influence on the growth of velvetgrass, while such an effect was not observed for ryegrass. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Comparative mapping of the wild perennial Glycine latifolia and soybean (G. max reveals extensive chromosome rearrangements in the genus Glycine.

    Directory of Open Access Journals (Sweden)

    Sungyul Chang

    Full Text Available Soybean (Glycine max L. Mer., like many cultivated crops, has a relatively narrow genetic base and lacks diversity for some economically important traits. Glycine latifolia (Benth. Newell & Hymowitz, one of the 26 perennial wild Glycine species related to soybean in the subgenus Glycine Willd., shows high levels of resistance to multiple soybean pathogens and pests including Alfalfa mosaic virus, Heterodera glycines Ichinohe and Sclerotinia sclerotiorum (Lib. de Bary. However, limited information is available on the genomes of these perennial Glycine species. To generate molecular resources for gene mapping and identification, high-density linkage maps were constructed for G. latifolia using single nucleotide polymorphism (SNP markers generated by genotyping by sequencing and evaluated in an F2 population and confirmed in an F5 population. In each population, greater than 2,300 SNP markers were selected for analysis and segregated to form 20 large linkage groups. Marker orders were similar in the F2 and F5 populations. The relationships between G. latifolia linkage groups and G. max and common bean (Phaseolus vulgaris L. chromosomes were examined by aligning SNP-containing sequences from G. latifolia to the genome sequences of G. max and P. vulgaris. Twelve of the 20 G. latifolia linkage groups were nearly collinear with G. max chromosomes. The remaining eight G. latifolia linkage groups appeared to be products of multiple interchromosomal translocations relative to G. max. Large syntenic blocks also were observed between G. latifolia and P. vulgaris. These experiments are the first to compare genome organizations among annual and perennial Glycine species and common bean. The development of molecular resources for species closely related to G. max provides information into the evolution of genomes within the genus Glycine and tools to identify genes within perennial wild relatives of cultivated soybean that could be beneficial to soybean

  19. Efeito de métodos e intensidades de pastejo sobre a ressemeadura natural de azevém anual = Effect of grazing methods and intensities on annual ryegrass under natural reseedling

    Directory of Open Access Journals (Sweden)

    Cristina Maria Pacheco Barbosa

    2008-10-01

    summer season. Ryegrass tillers from natural reseedling were counted after the soybean harvest. There was no interaction (p > 0.05 betweengrazing intensities and methods, and the effects for each treatment were independently analyzed. While the grazing methods did not affect natural ryegrass reseedling (p = 0.4636, there were significant effects under different grazing intensities (p = 0.0003. The numberof ryegrass tillers established by natural reseedling under low grazing intensity (6,776 tillers m-2 was much higher than under moderate grazing intensity (211 tillers m-2. Grazing intensity is a key factor to maintain ryegrass production in systems based on naturalreseedling.

  20. Perennial wheat lines have highly admixed population structure and elevated rates of outcrossing.

    Science.gov (United States)

    Perennial wheat has been proposed to alleviate long standing issues with soil erosion in annual cropping systems, while supporting rural communities and providing grain farmers with a marketable climate-resilient crop. The Washington State University perennial wheat breeding program has created sev...

  1. Adaptive management of perennial pepperweed for endangered specias and tidal marsh recovery

    Science.gov (United States)

    Perennial pepperweed has invaded a wide range of habitat types in the far west. In the San Francisco Estuary, dense infestations have impacted sensitive tidal wetlands and compromised endangered species recovery efforts. An adaptive management effort to reduce perennial pepperweed was initiated by...

  2. Control of perennial weeds by mechanical methods and anaerobic soil disinfection

    NARCIS (Netherlands)

    Huiting, H.F.; Bleeker, P.O.; Riemens, M.M.

    2011-01-01

    Perennial weeds are difficult to control and ask for a specific approach. During the most recent years it has even become a great challenge to control these weeds in conventional farming systems, although in comparison effective perennial weed control in organic farming systems remains more

  3. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  4. Fusarium-induced diseases of tropical, perennial crops.

    Science.gov (United States)

    Ploetz, Randy C

    2006-06-01

    ABSTRACT The world's oldest ecosystems are found in the tropics. They are diverse, highly evolved, but barely understood. This and subsequent papers describe diseases of tropical, perennial plants that are caused by Fusarium spp. Many of these are economically significant, difficult to manage, and of scientific interest. Some represent coevolved patho-systems (e.g., Panama disease, tracheomycosis of coffee, fusariosis of pineapple, and Fusarium wilt of oil palm), whereas others may be new-encounter diseases or are caused by generalist pathogens (cushion gall of cacao). New vector relationships are evident in other pathosystems (e.g., mango malformation), and two or more pathogens have been shown to cause some of the diseases (Panama disease and tracheomycosis of coffee). More work on these pathosystems is warranted as they could reveal much about the evolution of plant pathogens and the important diseases they cause.

  5. Airborne trace element pollution in 11 European cities assessed by exposure of standardised ryegrass cultures

    Science.gov (United States)

    Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Breuer, Jörn; Vergne, Philippe; Sanz, María José; Rasmussen, Stine; Ro-Poulsen, Helge; Ribas Artola, Àngela; Peñuelas, Josep; He, Shang; Garrec, Jean Pierre; Calatayud, Vicent

    Within a European biomonitoring programme, Italian ryegrass ( Lolium multiflorum Lam.) was employed as accumulative bioindicator of airborne trace elements (As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, V, Zn) in urban agglomerations. Applying a highly standardised method, grass cultures were exposed for consecutive periods of four weeks each to ambient air at up to 100 sites in 11 cities during 2000-2002. Results of the 2001 exposure experiments revealed a clear differentiation of trace element pollution within and among local monitoring networks. Pollution was influenced particularly by traffic emissions. Especially Sb, Pb, Cr, Fe, and Cu exhibited a very uneven distribution within the municipal areas with strong accumulation in plants from traffic-exposed sites in the city centres and close to major roads, and moderate to low levels in plants exposed at suburban or rural sites. Accumulation of Ni and V was influenced by other emission sources. The biomonitoring sites located in Spanish city centres featured a much higher pollution load by trace elements than those in other cities of the network, confirming previously reported findings obtained by chemical analyses of dust deposition and aerosols. At some heavily-trafficked sites, legal thresholds for Cu, Pb, and V contents in foodstuff and animal feed were reached or even surpassed. The study confirmed that the standardised grass exposure is a useful and reliable tool to monitor and to assess environmental levels of potentially toxic compounds of particulate matter.

  6. Identification of two distinct allergenic sites on ryegrass-pollen allergen, Lol p IV.

    Science.gov (United States)

    Jaggi, K S; Ekramoddoullah, A K; Kisil, F T; Dzuba-Fischer, J M; Rector, E S; Sehon, A H

    1989-04-01

    Lol p IV is an important allergen of ryegrass pollen. For the immunochemical identification of antigenic and/or allergenic site(s), murine monoclonal antibodies (MAbs) were prepared against Lol p IV. The hybridoma cell-culture supernatants were screened for anti-Lol p IV antibodies by a combination of ELISA and Western immunoblot analyses. The MAbs were finally purified from ascites on a Mono Q ion-exchange column. In a competitive radioimmunoassay with Lol p IV as the solid phase and 125I-labeled MAbs, it was established that MAbs 90, 91, 92, 93, and 94, although they differed in their relative affinities, recognized in common with one another an epitope designated as antigenic site A, whereas MAb 12 recognized a different epitope referred to as site B. Sites A and B were also demonstrated to constitute allergenic determinants of Lol p IV. Differences in the repertoire of specificities of the human IgE antibodies directed to Lol p IV were also demonstrated. Interestingly, it was found that sera from both allergic as well as from nonatopic individuals had IgG antibodies to sites A and/or B.

  7. Relationship between metal speciation in soil solution and metal adsorption at the root surface of ryegrass.

    Science.gov (United States)

    Kalis, Erwin J J; Temminghoff, Erwin J M; Town, Raewyn M; Unsworth, Emily R; van Riemsdijk, Willem H

    2008-01-01

    The total metal content of the soil or total metal concentration in the soil solution is not always a good indicator for metal availability to plants. Therefore, several speciation techniques have been developed that measure a defined fraction of the total metal concentration in the soil solution. In this study the Donnan Membrane Technique (DMT) was used to measure free metal ion concentrations in CaCl(2) extractions (to mimic the soil solution, and to work under standardized conditions) of 10 different soils, whereas diffusive gradients in thin-films (DGT) and scanning chronopotentiometry (SCP) were used to measure the sum of free and labile metal concentrations in the CaCl(2) extracts. The DGT device was also exposed directly to the (wetted) soil (soil-DGT). The metal concentrations measured with the speciation techniques are related to the metal adsorption at the root surface of ryegrass (Lolium perenne L.), to be able to subsequently predict metal uptake. In most cases the metal adsorption related pH-dependently to the metal concentrations measured by DMT, SCP, and DGT in the CaCl(2) extract. However, the relationship between metal adsorption at the root surface and the metal concentrations measured by the soil-DGT was not-or only slightly-pH dependent. The correlations between metal adsorption at the root surface and metal speciation detected by different speciation techniques allow discussion about rate limiting steps in biouptake and the contribution of metal complexes to metal bioavailability.

  8. The influence of nitrilotriacetate on heavy metal uptake of lettuce and ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Kulli, B.; Balmer, M.; Krebs, R.; Lothenbach, B.; Geiger, G.; Schulin, R.

    1999-12-01

    Metal uptake and removal from the soil by plants may be a useful measure to remediate contaminated soils. These processes can be enhanced by adding metal chelators to soil. The authors investigated the effect of nitrolotriacetate (NTA) and urea on the uptake of Cd, Cu, and Zn by lettuce (Lactuca sativa L. ev. Orion) and Italian ryegrass (Lolium perenne L. ev. Bastion) in pot experiments. Nitric acid-extractable heavy metal concentrations in the contaminated soil were 2 mg Cd, 530 mg Cu, and 700 mg Zn/kg. Three NTA treatments were compared with two urea treatments, and a control. Nitrilotriacetate and urea increased the NaNO{sub 3}-extractable soil concentrations of the three metals. At the highest NTA dose, metal concentrations in the aboveground plant biomass was 4 to 24 times greater than in the control plants. While NTA increased plant metal concentrations, it reduced plant matter production. At lower doses, this effect was small. At the highest NTA dose, plant growth was almost completely inhibited. Severe visual symptoms indicated metal toxicity as the likely cause. The urea treatments generally increased the plant matter production. Total metal uptake was in general larger at the lowest or at the intermediate NTA dose than at the highest doses. Little additional total metal uptake was achieved with NTA treatments than with urea. Compared with the controls, neither NTA nor urea enhanced total uptake under the given conditions by more than threefold.

  9. Complementary effects of red clover inclusion in ryegrass-white clover swards for grazing and cutting

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Askegaard, Margrethe; Søegaard, Karen

    2014-01-01

    Increasing plant species diversity in grasslands may improve productivity and stability of yields. In a field experiment, we investigated the herbage dry-matter (DM) yield and crude protein content of two-species swards of perennial ryegrass–white clover (Lolium perenne L.–Trifolium repens L...... clover in sown swards are discussed. These may include higher nitrogen-use efficiency in ruminants, increased soil fertility and improved sward flexibility to cope with changing managements. The findings also suggest positive yield effects of alternating between cutting and grazing within the season...

  10. Bud Dormancy in Perennial Fruit Tree Species: A Pivotal Role for Oxidative Cues

    Directory of Open Access Journals (Sweden)

    Rémi Beauvieux

    2018-05-01

    Full Text Available For perennial plants, bud dormancy is a crucial step as its progression over winter determines the quality of bud break, flowering, and fruiting. In the past decades, many studies, based on metabolic, physiological, subcellular, genetic, and genomic analyses, have unraveled mechanisms underlying bud dormancy progression. Overall, all the pathways identified are interconnected in a very complex manner. Here, we review early and recent findings on the dormancy processes in buds of temperate fruit trees species including hormonal signaling, the role of plasma membrane, carbohydrate metabolism, mitochondrial respiration and oxidative stress, with an effort to link them together and emphasize the central role of reactive oxygen species accumulation in the control of dormancy progression.

  11. Understanding the Strategies to Overcome Phosphorus–Deficiency and Aluminum–Toxicity by Ryegrass Endophytic and Rhizosphere Phosphobacteria

    Directory of Open Access Journals (Sweden)

    Patricio J. Barra

    2018-06-01

    Full Text Available Phosphobacteria, secreting organic acids and phosphatases, usually favor plant performance in acidic soils by increasing phosphorus (P availability and aluminum (Al complexing. However, it is not well-known how P-deficiency and Al-toxicity affect the phosphobacteria physiology. Since P and Al problems often co-occur in acidic soils, we have therefore proposed the evaluation of the single and combined effects of P-deficiency and Al-toxicity on growth, organic acids secretion, malate dehydrogenase (mdh gene expression, and phosphatase activity of five Al-tolerant phosphobacteria previously isolated from ryegrass. These phosphobacteria were identified as Klebsiella sp. RC3, Stenotrophomona sp. RC5, Klebsiella sp. RCJ4, Serratia sp. RCJ6, and Enterobacter sp. RJAL6. The strains were cultivated in mineral media modified to obtain (i high P in absence of Al–toxicity, (ii high P in presence of Al–toxicity, (iii low P in absence of Al–toxicity, and (iv low P in presence of Al–toxicity. High and low P were obtained by adding KH2PO4 at final concentration of 1.4 and 0.05 mM, respectively. To avoid Al precipitation, AlCl3 × 6H2O was previously complexed to citric acid (sole carbon source in concentrations of 10 mM. The secreted organic acids were identified and quantified by HPLC, relative mdh gene expression was determined by qRT-PCR and phosphatase activity was colorimetrically determined using p-nitrophenyl phosphate as substrate. Our results revealed that although a higher secretion of all organic acids was achieved under P–deficiency, the patterns of organic acids secretion were variable and dependent on treatment and strain. The organic acid secretion is exacerbated when Al was added into media, particularly in the form of malic and citric acid. The mdh gene expression was significantly up–regulated by the strains RC3, RC5, and RCJ6 under P–deficiency and Al–toxicity. In general, Al–tolerant phosphobacteria under P deficiency

  12. Efficacy of montelukast for treating perennial allergic rhinitis.

    Science.gov (United States)

    Philip, George; Williams-Herman, Debora; Patel, Piyush; Weinstein, Steven F; Alon, Achilles; Gilles, Leen; Tozzi, Carol A; Dass, S Balachandra; Reiss, Theodore F

    2007-01-01

    Perennial allergic rhinitis (PAR) is a chronic inflammatory nasal condition in individuals exposed year-round to allergens. This was a double-blind study of 15- to 85-year-old patients randomly allocated to montelukast, 10 mg (n=630), placebo (n=613), or the positive control cetirizine, 10 mg (n=122) for 6 weeks. The primary efficacy end point was change from baseline in Daytime Nasal Symptoms Score (DNSS; mean of congestion, rhinorrhea, sneezing, and itching scores, rated daily by patients [scale: 0=none to 3=severe]) averaged during the initial 4 weeks (primary analysis) or entire 6 weeks of treatment. Also assessed were combined post hoc results of primary end point data from this study and another similarly designed study (Patel P, et al. Randomized, double-blind, placebo-controlled study of montelukast for treating perennial allergic rhinitis, Ann Allergy Asthma Immunol 95:551, 2005). Over 4 weeks, montelukast showed numerical improvement over placebo in DNSS (least-squares mean difference of -0.04 [95% confidence interval (CI}, -0.09, 0.01]); the difference between cetirizine and placebo was significant: -0.10 (95% CI, -0.19, -0.01). However, when averaged over 6 weeks, neither active treatment was significantly different from placebo. The Rhinoconjunctivitis Quality-of-Life score was significantly improved by montelukast (p < 0.05), but not by cetirizine, during 4 and 6 weeks. The treatment effect of montelukast, but not cetirizine, generally remained consistent through the 6 weeks of treatment. In pooled data, montelukast consistently improved DNSS versus placebo during all 6 weeks of treatment (-0.07 [95% CI, -0.10, -0.041). In conclusion, montelukast produced numerical improvement in daytime nasal symptoms and significant improvement in quality of life. In a pooled post hoc analysis, montelukast provided consistent improvement in daytime nasal symptoms over 6 weeks, supportive of an overall benefit in PAR.

  13. Persistence of Overseeded Cool-Season Grasses in Bermudagrass Turf

    OpenAIRE

    Thomas Serensits; Matthew Cutulle; Jeffrey F. Derr

    2011-01-01

    Cool-season grass species are commonly overseeded into bermudagrass turf for winter color. When the overseeded grass persists beyond the spring; however, it becomes a weed. The ability of perennial ryegrass, Italian (annual) ryegrass, intermediate ryegrass, and hybrid bluegrass to persist in bermudagrass one year after seeding was determined. Perennial ryegrass, intermediate ryegrass, and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass di...

  14. Dry matter production of perennial pasture Tifton 85 (Cynodon spp under different doses of fertilization

    Directory of Open Access Journals (Sweden)

    Karlize Prigol

    2012-12-01

    Full Text Available Dairy farming is an activity that provides the small rural farmer the opportunity to earn income in small areas of land. The perennial pastures represent a source for a cheap and nutritious diet for the animals. The correct management of perennial pastures can be the key to sustainability in the dairy business, resulting in the preservation or recovery of the balance of a pasture system, starting with the pursuit of production with low costs and good pasture production per unit area. The correct choice of fertilizer is of great importance to ensure the continuous production of pasture both in quantity and in quality. The aim of this study was to evaluate the dry matter production of perennial pasture consisting of Tifton 85 (Cynodon spp under different nutrient sources on a typical dystrophic Red Latosol, presents in a region where the climate is characterized as humid-mesothermic with a hot summer, Cfa according to Köppen, with an average annual rainfall of 2039 mm, well distributed throughout the year and average annual temperatures around 18 º C, varying monthly from 14.1 to 23 º C. The treatments consisted of three nutrient sources: 1 organic manure, a base of chicken bedding (average values of reference NPK (02/03/02, 2 organic manure + mineral - organic mineral, with application of 606 kg ha-1 (04/10/10 Formula, aiming to adjust the same amounts of NPK supplied by mineral fertilizer and, 3 Mineral. The experimental design was a randomized blocks with nine replications. We collected five samples of each pasture treatment for determination of the average. After cutting the pasture of Tifton 85, the samples were subjected to weighing for determination of wet weight and then taken to the drying oven (temperature 65 ° C for 72 hours to determine dry matter production. The statistical analysis was performed with SAS for Windows computer system (SAS and the results submitted to the Tukey test at 5%. The highest dry matter yield (kg ha-1 was

  15. Does introduction of clover in an agricultural grassland affect the food base and functional diversity of Collembola?

    DEFF Research Database (Denmark)

    D'Annibale, Alessandra; Sechi, Valentina; Larsen, Thomas

    2017-01-01

    plots with either perennial ryegrass (Lolium perenne L.), whiteclover (Trifolium repens L.) or a mixture of both in a Danish agricultural grassland 6 and 14 months after establishing the leys (September and May, respectively). Diet preferences were investigated via stable isotope analyses (SIA...... in the white clover than ryegrass plots. Changes in taxa specific density and traits distribution as a response to the C:N ratio of plant material, suggest that plant material quality was the main factor affecting the collembolan community,especially when comparing the two sampling occasions. Functional...... richness decreased under conditions of low quality material. In contrast to our hypothesis, population densities did not increase under mixture treatment and functional richness decreased. Our results suggest that habitat changes, via different plant composition, can affect some functional groups, having...

  16. Temperature Effects on the Seed Germination of Some Perennial and Annual Species of Asteraceae Family

    Directory of Open Access Journals (Sweden)

    Zarghani Hadi

    2014-12-01

    Full Text Available Temperature is the most critical factor determining success or failure of plant establishment. Seed germination response of five medicinal species include three seed-propagated perennial species, Cichorium intybus, cynara scolymus and Echinacea purpurea and vegetative-reproduction perennial species, Achillea millefolium and annual species, Matricaria aurea were assessed at constant temperatures. The seeds were exposed to constant temperatures of 5, 10, 15, 20, 25, 30, 35, 40 and 45°C under total darkness. Germination percentage of all the species were significantly affected by various temperatures (p ≤ 0.001. A. millefolium did not germinate at 5-10 and 35-45°C, but showed noticeable germination percentage (73.3-100% at temperatures ranged from 15-30° C. The highest total germination percentage was observed within the range of 15-35 °C for other species. Also, we calculated cardinal temperatures (the minimum, optimum and maximum temperature for seed germination of species. The highest value for minimum temperature was 10.07ºC in A. millefolium followed by C. scolymus and M. aurea (5ºC while the lowest was for E. purpurea and C. intybus (2.68 and 2.90ºC respectively. The lowest value for optimum temperature was detected in A. millefolium (22.72ºC and M. aurea (23.88°C while the maximum values were observed in E. purpurea and C. intybus (30.40ºC and 29.90ºC respectively. Based on results of present study we concluded that species with both vegetative and seed-propagated reproduction forms like A. millefolium had smaller temperature range rather those with just one way of reproduction (seed production.

  17. The Effect of Heavy Metal Contaminated Soil on Growth and Development of Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Żurek G.

    2013-04-01

    Full Text Available Contamination of agricultural land in Poland by heavy metals is not a general problem but is limited to industrial areas. In regions of long history of industrial emission, of elevated levels of lead, cadmium, zinc and other ions during coal and ore mining and processing, as for example in Silesia, about 10 % of agricultural land may be characterized by exceeded maximum residue limits for Cd, Pb, Cu, Ni and Zn ions. Since the maintenance of agricultural areas in those regions is important from an ecological standpoint, the alternative farming activities are needed. Perennial grass biomass production for energy purposes is currently the best solution for majority of agricultural areas not suitable for food production in Poland. Along with increasing knowledge on separation and utilization of heavy metals (HM during and after biomass processing, phytoremediation of polluted soils will become important and valuable. To detect the effect of soil HM ions concentration on growth and development of selected, tall growing and high biomass yielding perennial grass cultivars, the chlorophyll fluorescence parameters were registered. The elevated content of Pb, Cd and Zn ions in soil influenced on decrease of: minimal (Fo, maximal (Fm and variable (Fv fluorescence level as well as on total complementary area on a diagram of chlorophyll a fluorescence induction curve (Area. Based on detected parameters it was concluded, that the high level of HM ions in soils negatively affected the efficiency of photosynthesis. Therefore, plant growth, as well as development of generative shoots and finally the biomass yield were reduced in some cultivars. Among tested cultivars different reaction for HM ions in polluted soil were noted: from only slightly modified parameters of photosynthesis and unreduced yield (Elytrigia elongata cv. Bamar and Arrhenatherum elatius cv. Wiwena to significantly reduced Fo, Fv, Fm and biomass yield (Bromus carinathus cv. Broma and Bromus

  18. Mutants of the major ryegrass pollen allergen, Lol p 5, with reduced IgE-binding capacity: candidates for grass pollen-specific immunotherapy.

    Science.gov (United States)

    Swoboda, Ines; De Weerd, Nicole; Bhalla, Prem L; Niederberger, Verena; Sperr, W R; Valent, Peter; Kahlert, Helga; Fiebig, Helmut; Verdino, Petra; Keller, Walter; Ebner, Christof; Spitzauer, Susanne; Valenta, Rudolf; Singh, Mohan B

    2002-01-01

    More than 400 million individuals are sensitized to grass pollen allergens. Group 5 allergens represent the most potent grass pollen allergens recognized by more than 80 % of grass pollen allergic patients. The aim of our study was to reduce the allergenic activity of group 5 allergens for specific immunotherapy of grass pollen allergy. Based on B- and T-cell epitope mapping studies and on sequence comparison of group 5 allergens from different grasses, point mutations were introduced by site-directed mutagenesis in highly conserved sequence domains of Lol p 5, the group 5 allergen from ryegrass. We obtained Lol p 5 mutants with low IgE-binding capacity and reduced allergenic activity as determined by basophil histamine release and by skin prick testing in allergic patients. Circular dichroism analysis showed that these mutants exhibited an overall structural fold similar to the recombinant Lol p 5 wild-type allergen. In addition, Lol p 5 mutants retained the ability to induce proliferation of group 5 allergen-specific T cell lines and clones. Our results demonstrate that a few point mutations in the Lol p 5 sequence yield mutants with reduced allergenic activity that represent potential vaccine candidates for immunotherapy of grass pollen allergy.

  19. Using the Model Perennial Grass Brachypodium sylvaticum to Engineer Resistance to Multiple Abiotic Stresses

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Sean; Reguera, Maria; Sade, Nir; Cartwright, Amy; Tobias, Christian; Thilmony, Roger; Blumwald, Eduardo; Vogel, John

    2015-03-20

    We are using the perennial model grass Brachypodium sylvaticum to identify combinations of transgenes that enhance tolerance to multiple, simultaneous abiotic stresses. The most successful transgene combinations will ultimately be used to create improved switchgrass (Panicum virgatum L.) cultivars. To further develop B. sylvaticum as a perennial model grass, and facilitate our planned transcriptional profiling, we are sequencing and annotating the genome. We have generated ~40x genome coverage using PacBio sequencing of the largest possible size selected libraries (18, 22, 25 kb). Our initial assembly using only long-read sequence contained 320 Mb of sequence with an N50 contig length of 315 kb and an N95 contig length of 40 kb. This assembly consists of 2,430 contigs, the largest of which was 1.6 Mb. The estimated genome size based on c-values is 340 Mb indicating that about 20 Mb of presumably repetitive DNA remains yet unassembled. Significantly, this assembly is far superior to an assembly created from paired-end short-read sequence, ~100x genome coverage. The short-read-only assembly contained only 226 Mb of sequence in 19k contigs. To aid the assembly of the scaffolds into chromosome-scale assemblies we produced an F2 mapping population and have genotyped 480 individuals using a genotype by sequence approach. One of the reasons for using B. sylvaticum as a model system is to determine if the transgenes adversely affect perenniality and winter hardiness. Toward this goal, we examined the freezing tolerance of wild type B. sylvaticum lines to determine the optimal conditions for testing the freezing tolerance of the transgenics. A survey of seven accessions noted significant natural variation in freezing tolerance. Seedling or adult Ain-1 plants, the line used for transformation, survived an 8 hour challenge down to -6 oC and 50% survived a challenge down to -9 oC. Thus, we will be able to easily determine if the transgenes compromise freezing tolerance. In the

  20. [Effect of Ryegrass and Arbuscular Mycorrhizal on Cd Absorption by Varieties of Tomatoes and Cadmium Forms in Soil].

    Science.gov (United States)

    Chen, Yong-qin; Jiang, Ling; Xu, Wei-hong; Chi, Sun-lin; Chen, Xu-gen; Xie, Wen-wen; Xiong, Shi- juan; Zhang, Jin-zhong; Xiong, Zhi-ting

    2015-12-01

    Field trial was carried out to investigate the effects of ryegrass and arbuscular mycorrhizal single or compound treatment to two varieties of tomato ("Defu mm-8" and "Luobeiqi") on the plant growth, concentrations and accumulations of Cd as well as the impact on microorganisms, enzyme activities, pH and Cd forms in soil when exposed to Cd (5.943 mg · kg⁻¹). The results showed that dry weights of fruit, root, stem, leaf and plant significantly increased by single or compound treatment of ryegrass and arbuscular mycorrhizal by 14.1%-38.4% and 4.2%-18.3%, 20.9%-31.5% and 8.4%-10.3%, 13.0%-16.8% and 3.0%-9.5%, 10.7%- 16.8% and 2.7%-7.6%, 14.3%-36.6% and 4.5%-16.8%, respectively. The amounts of bacteria, fungi, actinomycetes of soil and the activities of urease, invertase, acid phosphatase, catalase in soil were increased by single or compound treatment of ryegrass and arbuscular mycorrhizal, and the soil microorganism amounts and enzyme activities significantly differed between the two varieties of tomato and treatments (P arbuscular mycorrhizal, while the concentrations of EXC-Cd, CAB-Cd, Fe-Mn-Cd and total Cd in soil were decreased, and the total Cd content was decreased by 16.9%-27.8%. Cadmium concentrations in fruit, leaf, stem and root of both varieties were significantly decreased by 6.9%-40.9%, 5.7%-40.1%, 4.6%-34.7% and 9.8%-42.4%, respectively. Cadmium accumulations in tomato were in order of leaf > stem > root > fruit. Comparing the two tomato varieties, Cd concentrations and Cd accumulations in fruit and plant were in order of "Luobeiqi" arbuscular mycorrhizal.

  1. Effect of four acidifying materials added to a calcareous soil on the availability of phosphorus to ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Sen Gupta, M B; Cornfield, A H

    1964-12-01

    Ryegrass was grown in a pot test using a calcareous soil (0.36% calcium carbonate) treated with sulfur, ammonium sulfate, ferrous sulfate, and aluminium sulfate at 0.1% sulfur-equivalent, with potassium nitrate added where necessary, including the control, to equalize nitrogen supply. The sulfur treatment was the only one which significantly increased dry matter yields, total phosphorus uptake and top/root ratios in dry matter yields and total phosphorus. The ammonium sulfate, ferrous sulfate, and aluminium sulfate treatments significantly reduced top/root ratios in dry-matter yields and total phosphorus. 6 references, 1 table.

  2. The potential of perennial cave ice in isotope palaeoclimatology

    International Nuclear Information System (INIS)

    Yonge, Charles J.; MacDonald, William D.

    1999-01-01

    Perennial ice from caves on and to the east of the Canadian Great Divide yield delta O 18 and delta D values which are usually high measurements where compared with the average precipitation for the region. Furthermore, these ice data fall below and along lines of lower slope than the Global Meteoric Water Line. To explain the observed relationships, we propose the following process. a vapour-ice isotopic fractionation mechanism operates on warm season vapour when it precipitates as hoar ice on entering the caves. The subsequent fall of hoar to the cave floor through mechanical overloading along with ice derived from ground-water seepage (with a mean annual isotopic composition), results in massive ice formation of a mixed composition. This mixed composition is what is observed in the characteristic relationships found here. Such findings suggest that a warm versus cold climate interpretation for ancient cave ice may be the opposite of that found in the more familiar polar and glacial ice caves. (Author) 3 figs., 1 tab., 12 refs

  3. Root proliferation in native perennial grasses of arid Patagonia, Argentina

    Institute of Scientific and Technical Information of China (English)

    Yanina A. TORRES; Mara M. MUJICA; Sandra S. BAIONI; Jos ENTO; Mara N. FIORETTI; Guillermo TUCAT; Carlos A. BUSSO; Oscar A. MONTENEGRO; Leticia ITHURRART; Hugo D. GIORGETTI; Gustavo RODRGUEZ; Diego BENTIVEGNA; Roberto E. BREVEDAN; Osvaldo A. FERNNDEZ

    2014-01-01

    Pappophorum vaginatum is the most abundant C4 perennial grass desirable to livestock in rangelands of northeastern Patagonia, Argentina. We hypothesized that (1) defoliation reduce net primary productivity, and root length density and weight in the native species, and (2) root net primary productivity, and root length density and weight, are greater in P. vaginatum than in the other, less desirable, native species (i.e., Aristida spegazzinii, A. subulata and Sporobolus cryptandrus). Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons. Root proliferation was measured using the cylinder method. Cylindrical, iron structures, wrapped up using nylon mesh, were buried diagonally from the periphery to the center on individual plants. These structures, initially filled with soil without any organic residue, were dug up from the soil on 25 April 2008, after two successive defoliations in mid-spring 2007. During the second growing season (2008-2009), cylinders were destructively harvested on 4 April 2009, after one or two defoliations in mid-and/or late-spring, respectively. Roots grown into the cylinders were obtained after washing the soil manually. Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice, which supported the first hypothesis. The greater root net primary productivity, root length den-sity and weight in P. vaginatum than in the other native species, in support of the second hypothesis, could help to explain its greater abundance in rangelands of Argentina.

  4. Modelling farmer uptake of perennial energy crops in the UK

    International Nuclear Information System (INIS)

    Sherrington, Chris; Moran, Dominic

    2010-01-01

    The UK Biomass Strategy suggests that to reach the technical potential of perennial energy crops such as short rotation coppice (SRC) willow and miscanthus by 2020 requires 350,000 hectares of land. This represents a more than 20-fold increase on the current 15,546 hectares. Previous research has identified several barriers to adoption, including concerns over security of income from contracts. In addition, farmers perceive returns from these crops to be lower than for conventional crops. This paper uses a farm-level linear programming model to investigate theoretical uptake of energy crops at different gross margins under the assumption of a profit-maximising decision maker, and in the absence of known barriers to adoption. The findings suggest that while SRC willow, at current prices, remains less competitive, returns to miscanthus should have encouraged adoption on a wider scale than at present. This highlights the importance of the barriers to adoption. Recently announced contracts for miscanthus appear to offer a significant premium to farmers in order to encourage them to grow the crops. This raises the question of whether a more cost-effective approach would be for government to provide guarantees addressing farmers concerns including security of income from the contracts. Such an approach should encourage adoption at lower gross margins. (author)

  5. BETA DIVERSITY AND COMMUNITY DIFFERENTIATION IN DRY PERENNIAL SAND GRASSLANDS

    Directory of Open Access Journals (Sweden)

    E. KOVACS-LANG

    2011-01-01

    Full Text Available The spatial variability of species composition was studied in perennial sand grasslands in Hungary at multiple scales. Three sites were compared along an aridity gradient. Existing differences in climate along this ca. 200 km gradient correspond to regional climate changes predicted for the next 20-30 years. Six stands of Festucetum vaginatae grasslands were selected at each site within 400 x 1200 m areas for representing the coarse-scale within-site heterogeneity. Fine-scale compositional heterogeneity of vegetation within stands was sampled by recording the presence of species along 52 m long circular belt transects of 1040 units of 5 cm x 5 cm contiguous microquadrats. This sampling design enabled us to study the patterns of species combinations at a wide range of scales. The highest variability of plant species combinations appeared at very fine scales, between 10 cm and 25 cm. Differences in beta diversity along the gradient were scale-dependent. We found a decreasing trend of beta diversity with increasing aridity at fine scale, and on the contrary, an increasing trend at landscape scale. We conclude that the major trend of the vegetation differentiation due to aridity is the decrease of compositional variability at fine-scale accompanied by a coarse-scale diversification.

  6. Potential impacts to perennial springs from tar sand mining, processing, and disposal on the Tavaputs Plateau, Utah, USA

    International Nuclear Information System (INIS)

    Johnson, William P.; Frederick, Logan E.; Millington, Mallory R.; Vala, David; Reese, Barbara K.; Freedman, Dina R.; Stenten, Christina J.; Trauscht, Jacob S.; Tingey, Christopher E.; Kip Solomon, D.; Fernandez, Diego P.; Bowen, Gabriel J.

    2015-01-01

    Similar to fracking, the development of tar sand mining in the U.S. has moved faster than understanding of potential water quality impacts. Potential water quality impacts of tar sand mining, processing, and disposal to springs in canyons incised approximately 200 m into the Tavaputs Plateau, at the Uinta Basin southern rim, Utah, USA, were evaluated by hydrogeochemical sampling to determine potential sources of recharge, and chemical thermodynamic estimations to determine potential changes in transfer of bitumen compounds to water. Because the ridgetops in an area of the Tavaputs Plateau named PR Spring are starting to be developed for their tar sand resource, there is concern for potential hydrologic connection between these ridgetops and perennial springs in adjacent canyons on which depend ranching families, livestock, wildlife and recreationalists. Samples were collected from perennial springs to examine possible progression with elevation of parameters such as temperature, specific conductance, pH, dissolved oxygen, isotopic tracers of phase change, water-rock interaction, and age since recharge. The groundwater age dates indicate that the springs are recharged locally. The progression of hydrogeochemical parameters with elevation, in combination with the relatively short groundwater residence times, indicate that the recharge zone for these springs includes the surrounding ridges, and thereby suggests a hydrologic connection between the mining, processing, disposal area and the springs. Estimations based on chemical thermodynamic approaches indicate that bitumen compounds will have greatly enhanced solubility in water that comes into contact with the residual bitumen–solvent mixture in disposed tailings relative to water that currently comes into contact with natural tar. - Highlights: • The potential water quality impacts of the first US tar sand development are considered. • Analyses of perennial springs in adjacent canyons indicate hydrologic

  7. Potential impacts to perennial springs from tar sand mining, processing, and disposal on the Tavaputs Plateau, Utah, USA

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, William P.; Frederick, Logan E.; Millington, Mallory R. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States); Vala, David [Murray High School, Murray, UT 84107 (United States); Reese, Barbara K. [Butler Middle School, Cottonwood Heights, UT 84121 (United States); Freedman, Dina R. [Hillside Middle School, Salt Lake City, UT 84108 (United States); Stenten, Christina J. [Draper Park Middle School, Draper, UT 84020 (United States); Trauscht, Jacob S.; Tingey, Christopher E.; Kip Solomon, D.; Fernandez, Diego P.; Bowen, Gabriel J. [University of Utah, Department of Geology & Geophysics, Salt lake City, UT 84112 (United States)

    2015-11-01

    Similar to fracking, the development of tar sand mining in the U.S. has moved faster than understanding of potential water quality impacts. Potential water quality impacts of tar sand mining, processing, and disposal to springs in canyons incised approximately 200 m into the Tavaputs Plateau, at the Uinta Basin southern rim, Utah, USA, were evaluated by hydrogeochemical sampling to determine potential sources of recharge, and chemical thermodynamic estimations to determine potential changes in transfer of bitumen compounds to water. Because the ridgetops in an area of the Tavaputs Plateau named PR Spring are starting to be developed for their tar sand resource, there is concern for potential hydrologic connection between these ridgetops and perennial springs in adjacent canyons on which depend ranching families, livestock, wildlife and recreationalists. Samples were collected from perennial springs to examine possible progression with elevation of parameters such as temperature, specific conductance, pH, dissolved oxygen, isotopic tracers of phase change, water-rock interaction, and age since recharge. The groundwater age dates indicate that the springs are recharged locally. The progression of hydrogeochemical parameters with elevation, in combination with the relatively short groundwater residence times, indicate that the recharge zone for these springs includes the surrounding ridges, and thereby suggests a hydrologic connection between the mining, processing, disposal area and the springs. Estimations based on chemical thermodynamic approaches indicate that bitumen compounds will have greatly enhanced solubility in water that comes into contact with the residual bitumen–solvent mixture in disposed tailings relative to water that currently comes into contact with natural tar. - Highlights: • The potential water quality impacts of the first US tar sand development are considered. • Analyses of perennial springs in adjacent canyons indicate hydrologic

  8. Identification of T-cell epitopes of Lol p 9, a major allergen of ryegrass (Lolium perenne) pollen.

    Science.gov (United States)

    Blaher, B; Suphioglu, C; Knox, R B; Singh, M B; McCluskey, J; Rolland, J M

    1996-07-01

    T-cell recognition of Lol p 9, a major allergen of ryegrass pollen, was investigated by using a T-cell line and T-cell clones generated from the peripheral blood of an atopic donor. The T-cell line reacted with purified Lol p 9, as well as with crude ryegrass pollen extract, but failed to cross-react with Bermuda grass pollen extract. All of six T-cell clones generated from this line proliferated in response to Lol p 9. Epitope mapping was carried out with a panel of 34 overlapping synthetic peptides, which spanned the entire sequence of the Lol p 9 12R isoform. The T-cell line responded to two of the peptides, Lol p 9 (105-116) and Lol p 9 (193-204), whereas reactivity with one or other of these peptides was shown by five T-cell clones. These two peptides contained sequences consistent with motifs previously reported for major histocompatibility complex class II-restricted peptides. HLA antibody blocking studies showed that presentation of peptide Lol p 9 (105-116) to one T-cell clone was HLA-DR-restricted; this clone expressed a T helper cell phenotype (CD3+, CD4+) and the T-cell receptor alpha beta. The identification of immunodominant T-cell epitope(s) on allergens is essential for devising safer and more effective immunotherapy strategies, which can interrupt the chain of events leading to allergic disease.

  9. Enhanced phytoextraction of uranium and selected heavy metals by Indian mustard and ryegrass using biodegradable soil amendments

    Energy Technology Data Exchange (ETDEWEB)

    Duquene, L. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium); Vandenhove, H. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium)], E-mail: hvandenh@sckcen.be; Tack, F.; Meers, E. [Ghent University, Laboratory for Analytical Chemistry and Applied Ecochemistry, Coupure Links 653, B-9000 Gent (Belgium); Baeten, J. [Katholieke Hogeschool Kempen, Department of Health-Care and Chemistry, Kleinhoefstraat 4, B-2440 Geel (Belgium); Wannijn, J. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium)

    2009-02-15

    The applicability of biodegradable amendments in phytoremediation to increase the uptake of uranium (U), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn) by Indian mustard (Brassica juncea) and ryegrass (Lolium perenne) was tested in a greenhouse experiment. Plants were cultivated during one month on two soils with naturally or industrially increased contaminant levels of U. Treatments with citric acid, NH{sub 4}-citrate/citric acid, oxalic acid, S,S-ethylenediamine disuccinic acid (EDDS) or nitrilotriacetic acid (NTA) at a rate of 5 mmol kg{sup -1} dry soil caused increases in soil solution concentrations that were up to 18 times higher for U and up to 1570 times higher for other heavy metals, compared to the controls. Shoot concentrations increased to a much smaller extent. With EDDS, 19-, 34-, and 37-fold increases were achieved in shoots of Indian mustard for U, Pb and Cu, respectively. The increases in plant uptake of Cd, Cr and Zn were limited to a factor of four at most. Ryegrass generally extracted less U and metals than Indian mustard. Despite a marked increase of U and metal concentrations in shoots after addition of amendments, the estimated time required to obtain an acceptable reduction in soil contaminant concentrations was impractically long. Only for Cu and Zn in one of the studied soils, could the Flemish standards for clean soil theoretically be attained in less than 100 years.

  10. Enhanced phytoextraction of uranium and selected heavy metals by Indian mustard and ryegrass using biodegradable soil amendments

    International Nuclear Information System (INIS)

    Duquene, L.; Vandenhove, H.; Tack, F.; Meers, E.; Baeten, J.; Wannijn, J.

    2009-01-01

    The applicability of biodegradable amendments in phytoremediation to increase the uptake of uranium (U), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn) by Indian mustard (Brassica juncea) and ryegrass (Lolium perenne) was tested in a greenhouse experiment. Plants were cultivated during one month on two soils with naturally or industrially increased contaminant levels of U. Treatments with citric acid, NH 4 -citrate/citric acid, oxalic acid, S,S-ethylenediamine disuccinic acid (EDDS) or nitrilotriacetic acid (NTA) at a rate of 5 mmol kg -1 dry soil caused increases in soil solution concentrations that were up to 18 times higher for U and up to 1570 times higher for other heavy metals, compared to the controls. Shoot concentrations increased to a much smaller extent. With EDDS, 19-, 34-, and 37-fold increases were achieved in shoots of Indian mustard for U, Pb and Cu, respectively. The increases in plant uptake of Cd, Cr and Zn were limited to a factor of four at most. Ryegrass generally extracted less U and metals than Indian mustard. Despite a marked increase of U and metal concentrations in shoots after addition of amendments, the estimated time required to obtain an acceptable reduction in soil contaminant concentrations was impractically long. Only for Cu and Zn in one of the studied soils, could the Flemish standards for clean soil theoretically be attained in less than 100 years

  11. Phenanthrene and Pyrene Modify the Composition and Structure of the Cultivable Endophytic Bacterial Community in Ryegrass (Lolium multiflorum Lam

    Directory of Open Access Journals (Sweden)

    Xuezhu Zhu

    2016-11-01

    Full Text Available This study provides new insights into the dynamics of bacterial community structure during phytoremediation. The communities of cultivable autochthonous endophytic bacteria in ryegrass exposed to polycyclic aromatic hydrocarbons (PAHs were investigated with regard to their potential to biodegrade PAHs. Bacterial counts and 16S rRNA gene sequence were used in the microbiological evaluation. A total of 33 endophytic bacterial strains were isolated from ryegrass plants, which represented 15 different genera and eight different classes, respectively. Moreover, PAH contamination modified the composition and structure of the endophytic bacterial community in the plants. Bacillus sp., Pantoea sp., Pseudomonas sp., Arthrobacter sp., Pedobacter sp. and Delftia sp. were only isolated from the seedlings exposed to PAHs. Furthermore, the dominant genera in roots shifted from Enterobacter sp. to Serratia sp., Bacillus sp., Pantoea sp., and Stenotrophomonas sp., which could highly biodegrade phenanthrene (PHE. However, the diversity of endophytic bacterial community was decreased by exposure to the mixture of PAHs, and increased by respective exposure to PHE and pyrene (PYR, while the abundance was increased by PAH exposure. The results clearly indicated that the exposure of plants to PAHs would be beneficial for improving the effectiveness of phytoremediation of PAHs.

  12. Enhanced phytoextraction of uranium and selected heavy metals by Indian mustard and ryegrass using biodegradable soil amendments.

    Science.gov (United States)

    Duquène, L; Vandenhove, H; Tack, F; Meers, E; Baeten, J; Wannijn, J

    2009-02-15

    The applicability of biodegradable amendments in phytoremediation to increase the uptake of uranium (U), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn) by Indian mustard (Brassica juncea) and ryegrass (Lolium perenne) was tested in a greenhouse experiment. Plants were cultivated during one month on two soils with naturally or industrially increased contaminant levels of U. Treatments with citric acid, NH4-citrate/citric acid, oxalic acid, S,S-ethylenediamine disuccinic acid (EDDS) or nitrilotriacetic acid (NTA) at a rate of 5 mmol kg(-1) dry soil caused increases in soil solution concentrations that were up to 18 times higher for U and up to 1570 times higher for other heavy metals, compared to the controls. Shoot concentrations increased to a much smaller extent. With EDDS, 19-, 34-, and 37-fold increases were achieved in shoots of Indian mustard for U, Pb and Cu, respectively. The increases in plant uptake of Cd, Cr and Zn were limited to a factor of four at most. Ryegrass generally extracted less U and metals than Indian mustard. Despite a marked increase of U and metal concentrations in shoots after addition of amendments, the estimated time required to obtain an acceptable reduction in soil contaminant concentrations was impractically long. Only for Cu and Zn in one of the studied soils, could the Flemish standards for clean soil theoretically be attained in less than 100 years.

  13. Integrated assessment of air pollution by metals and source apportionment using ryegrass (Lolium multiflorum Lam.) in southern Brazil.

    Science.gov (United States)

    Illi, Júlia Carolina; Vancetta, Tafael; Alves, Darlan Daniel; Osório, Daniela Montanari Migliavacca; Bianchin, Liane; de Quevedo, Daniela Müller; Juchem, Fernando

    2017-01-01

    One of the biggest environmental problems existing today is air pollution, which is characterized by the presence of toxic gases and metal pollutants, the latter of which is generally associated with emissions of particulate matter (PM) from industries or automotive vehicles. Biomonitoring is a method that can be used to assess air pollution levels because it makes it possible to determine what effects these air pollutants cause in living organisms and their responses. The species Lolium multiflorum Lam., known as ryegrass, is considered a good bioindicator of metals, since it accumulates these substances during exposure. This study proposes to conduct an integrated assessment of air quality using two different monitoring methodologies: biomonitoring with L. multiflorum and active monitoring in areas with different levels of urbanization and industrialization. Concentrations found in ryegrass plants revealed high levels of Pb, Cr, Zn, and Cu, indicating that vehicular and industrial emissions were the main sources of pollution. Analysis of PM also revealed soot and biogenic particles, which can transport metals. Therefore, with the proposed method, the anthropogenic impact on air pollution in the investigated area could be clearly demonstrated.

  14. The Performance of Early-Generation Perennial Winter Cereals at 21 Sites across Four Continents

    Directory of Open Access Journals (Sweden)

    Richard C. Hayes

    2018-04-01

    Full Text Available A network of 21 experiments was established across nine countries on four continents and spanning both hemispheres, to evaluate the relative performance of early generation perennial cereal material derived from wheat, rye, and barley and to inform future breeding strategies. The experimental lines were grown in replicated single rows, and first year production and phenology characteristics as well as yield and persistence for up to three years were monitored. The study showed that the existing experimental material is all relatively short-lived (≤3 years, with environments that are milder in summer and winter generally conferring greater longevity. No pedigree was superior across this diverse network of sites although better performing lines at the higher latitude sites were generally derived from Thinopyrum intermedium. By contrast, at lower latitudes the superior lines were generally derived from Th. ponticum and Th. elongatum parentage. The study observed a poor relationship between year 1 performance and productivity in later years, highlighting the need for perennial cereal material with greater longevity to underpin future experimental evaluation, and the importance for breeding programs to emphasize post-year 1 performance in their selections. Hybrid lines derived from the tetraploid durum wheat generally showed greater longevity than derivatives of hexaploid wheat, highlighting potential for greater use of Triticum turgidum in perennial wheat breeding. We advocate a model in future breeding initiatives that develops perennial cereal genotypes for specific target environments rather than a generic product for one global market. These products may include a diversity of cultivars derived from locally adapted annual and perennial parents. In this scenario the breeding program may have access to only a limited range of adapted perennial grass parents. In other situations, such as at very high latitude environments, perennial crops derived

  15. Supporting Agricultural Ecosystem Services through the Integration of Perennial Polycultures into Crop Rotations

    Directory of Open Access Journals (Sweden)

    Peter Weißhuhn

    2017-12-01

    Full Text Available This review analyzes the potential role and long-term effects of field perennial polycultures (mixtures in agricultural systems, with the aim of reducing the trade-offs between provisioning and regulating ecosystem services. First, crop rotations are identified as a suitable tool for the assessment of the long-term effects of perennial polycultures on ecosystem services, which are not visible at the single-crop level. Second, the ability of perennial polycultures to support ecosystem services when used in crop rotations is quantified through eight agricultural ecosystem services. Legume–grass mixtures and wildflower mixtures are used as examples of perennial polycultures, and compared with silage maize as a typical crop for biomass production. Perennial polycultures enhance soil fertility, soil protection, climate regulation, pollination, pest and weed control, and landscape aesthetics compared with maize. They also score lower for biomass production compared with maize, which confirms the trade-off between provisioning and regulating ecosystem services. However, the additional positive factors provided by perennial polycultures, such as reduced costs for mineral fertilizer, pesticides, and soil tillage, and a significant preceding crop effect that increases the yields of subsequent crops, should be taken into account. However, a full assessment of agricultural ecosystem services requires a more holistic analysis that is beyond the capabilities of current frameworks.

  16. Soil water status under perennial and annual pastures on an acid duplex soil

    International Nuclear Information System (INIS)

    Heng, L.K.; White, R.E.; Chen, D.

    2000-01-01

    A comprehensive field study of soil water balance, nitrogen (N) cycling, pasture management and animal production was carried out on an acid duplex soil at Book Book near Wagga Wagga in southern New South Wales. The experiment, carried out over a 3-year period, tested the hypothesis that sown perennial grass pastures improve the sustainability of a grazing system through better use of water and N. The treatments were: annual pastures without lime (AP-), annual pastures with lime (AP+), perennial pastures without lime (PP-) and perennial pastures with lime (PP+). Soil water measurement was made using a neutron probe on one set of the treatments comprising four adjacent paddocks. Over three winter and spring periods, the results showed that perennial grass pastures, especially PP+, consistently extracted about 40 mm more soil water each year than did the annual grass pastures. As a result, surface runoff, sub-surface flow and deep drainage (percolation below 180 cm depth) were about 40 mm less from the perennial pastures. The soil water status of the four pasture treatments was simulated reasonably well using a simple soil water model. Together with the long-term simulation of deep drainage, using past meteorological records, it is shown that proper management of perennial pastures can reduce recharge to groundwater and make pastoral systems more sustainable in the high rainfall zone. However, to completely reduce recharge, more-deeply rooted plants or trees are needed. (author)

  17. Controle químico de azevém (Lolium multiflorum L. na cultura do trigo Chemical control of ryegrass (Lolium multiflorum L. in wheat

    Directory of Open Access Journals (Sweden)

    N.G. Fleck

    1978-09-01

    relativa seletividade ao trigo, exerceram inadequada atividade de pós-emergência sobre o azevém. O tratamento diuron mostrou comportamento insuficiente tanto em relação ao controle do azevém, quanto ao rendimento do trigo. Os herbicidas cianazina e terbutrina proporcionaram adequado controle do azevém; contudo, suas seletividades à cultura do trigo foram muito reduzidas, além de terem causado diminuição no poder germinativo das sementes de trigo colhidas das parcelas tratadas com estes herbicidas.A field experiment was conducted during 1977 in the Central Depression region of Rio Grande do Sul to evaluate herbicide treatments to selectively control ryegrass (Lolium multif lorum L. in wheat (line E-7414, as well as to establish the competition levels between both grasses. The herbicides chlorbromuron, chlortoluron, cyanazine, diclofop, diuron, metoxuron, and terbutryn were compared with the control treatments: wheat without ryegrass, wheat competing with ryegrass, and ryegrass alone. All the herbicides were applied in postemergence, when wheat plants in the stage of 3-4 leaves, and ryegrass presented 1-3 leaves. It was found that, when ryegrass infestation was not controled by any means, an average reduction of 52% occurred in wheat seed yield. On the other hand, the wheat population which competed with ryegrass plants, caused a decrease in the order of 42% on ryegrass dry matter production. It was observed that all the herbicides presented phytotoxicity, causing from light to very severe injuries to wheat plants, depending on the product used; and that seed yields resulting from the chemical treatments were lower than that of the check plot free of ryegrass. However, all the compounds tested presented significant post-emergence activity, showing potential for ryegrass control. As well as ryegrass dry matter production, also visual evaluation of ryegrass control were appropriate methods to measure the herbicide effect. Among the herbicides evaluated, diclofop was

  18. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes

    Science.gov (United States)

    Two field trials were conducted in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop in a no-till soybean (Glycine max) planting to 1) reduce populations of plant-parasitic nematodes (i.e., the soybean cyst nematode, Heterodera glycines and lesion nematodes...

  19. Applying carbon dioxide, plant growth-promoting rhizobacterium and EDTA can enhance the phytoremediation efficiency of ryegrass in a soil polluted with zinc, arsenic, cadmium and lead.

    Science.gov (United States)

    Guo, Junkang; Feng, Renwei; Ding, Yongzhen; Wang, Ruigang

    2014-08-01

    This study was conducted to investigate the use of elevated carbon dioxide (CO2), plant growth-promoting rhizobacterium Burkholderia sp. D54 (PGPR) and ethylenediaminetetraacetic acid (EDTA) to enhance the phytoextraction efficiency of ryegrass in response to multiple heavy metal (or metalloid)-polluted soil containing zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb). All of the single or combined CO2, PGPR and EDTA treatments promoted ryegrass growth. The stimulation of ryegrass growth by CO2 and PGPR could primarily be attributed to the regulation of photosynthesis rather than decreased levels of Zn, As and Cd in the shoots. Most treatments seemed to reduce the Zn, As and Cd contents in the shoots, which might be associated with enhanced shoot biomass, thus causing a "dilution effect" regarding their levels. The combined treatments seemed to perform better than single treatments in removing Zn, As, Cd and Pb from soil, judging from the larger biomass and relatively higher total amounts (TAs) of Zn, As, Cd and Pb in both the shoots and roots. Therefore, we suggest that the CO2 plus PGPR treatment will be suitable for removing Zn, As, Cd and Pb from heavy metal (or metalloid)-polluted soils using ryegrass as a phytoremediation material. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Nutrients Can Enhance the Abundance and Expression of Alkane Hydroxylase CYP153 Gene in the Rhizosphere of Ryegrass Planted in Hydrocarbon-Polluted Soil

    Science.gov (United States)

    Arslan, Muhammad; Afzal, Muhammad; Amin, Imran; Iqbal, Samina; Khan, Qaiser M.

    2014-01-01

    Plant-bacteria partnership is a promising strategy for the remediation of soil and water polluted with hydrocarbons. However, the limitation of major nutrients (N, P and K) in soil affects the survival and metabolic activity of plant associated bacteria. The objective of this study was to explore the effects of nutrients on survival and metabolic activity of an alkane degrading rhizo-bacterium. Annual ryegrass (Lolium multiflorum) was grown in diesel-contaminated soil and inoculated with an alkane degrading bacterium, Pantoea sp. strain BTRH79, in greenhouse experiments. Two levels of nutrients were applied and plant growth, hydrocarbon removal, and gene abundance and expression were determined after 100 days of sowing of ryegrass. Results obtained from these experiments showed that the bacterial inoculation improved plant growth and hydrocarbon degradation and these were further enhanced by nutrients application. Maximum plant biomass production and hydrocarbon mineralization was observed by the combined use of inoculum and higher level of nutrients. The presence of nutrients in soil enhanced the colonization and metabolic activity of the inoculated bacterium in the rhizosphere. The abundance and expression of CYP153 gene in the rhizosphere of ryegrass was found to be directly associated with the level of applied nutrients. Enhanced hydrocarbon degradation was associated with the population of the inoculum bacterium, the abundance and expression of CYP153 gene in the rhizosphere of ryegrass. It is thus concluded that the combination between vegetation, inoculation with pollutant-degrading bacteria and nutrients amendment was an efficient approach to reduce hydrocarbon contamination. PMID:25360680

  1. Sheep Excreta as Source of Nitrous Oxide in Ryegrass Pasture in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Michely Tomazi

    2015-10-01

    Full Text Available ABSTRACT Livestock urine and dung are important components of the N cycle in pastures, but little information on its effect on soil nitrous oxide (N2O emissions is available. We conducted a short-term (39-day trial to quantify the direct N2O-N emissions from sheep excreta on an experimental area of ryegrass pasture growing on a Typic Paleudult in southern Brazil. Four rates of urine-N (161, 242, 323, and 403 kg ha-1 N and one of dung-N (13 kg ha-1 N were applied, as well as a control plot receiving no excreta. The N2O-N emission factor (EF = % of added N released as N2O-N for urine and dung was calculated, taking into account the N2O fluxes in the field, over a period of 39 days. The EF value of the urine and dung was used to estimate the emissions of N2O-N over a 90-day period of pasture in the winter under two grazing intensities (2.5 or 5.0 times the herbage intake potential of grazing lambs. The soil N2O-N fluxes ranged from 4 to 353 µg m-2h-1. The highest N2O-N fluxes occurred 16 days after application of urine and dung, when the highest soil nitrate content was also recorded and the water-filled pore space exceeded 60 %. The mean EF for urine was 0.25 % of applied N, much higher than that for dung (0.06 %. We found that N2O-N emissions for the 90-day winter pasture period were 0.54 kg ha-1 for low grazing intensity and 0.62 kg ha-1 for moderate grazing intensity. Comparison of the two forms of excreta show that urine was the main contributor to N2O-N emissions (mean of 36 %, whereas dung was responsible for less than 0.1 % of total soil N2O-N emissions.

  2. Seasonal Variations in Sugar Contents and Microbial Community Behavior in a Ryegrass Soil

    Science.gov (United States)

    Medeiros, P. M.; Fernandes, M. F.; Dick, R. P.; Simoneit, B. R.

    2004-12-01

    Soil is a complex mixture of numerous inorganic and organic constituents that vary in size, shape, chemical constitution and reactivity, and hosts numerous organisms. Total sugars have been estimated to constitute 10% (average) of soil organic matter, occurring in living and decaying organisms, as well as in extracellular materials. The role of sugars in soils is attributed to their influence on soil structure, chemical processes, plant nutrition and microbial activity. The sources of sugars in soils are: a) plants (the primary source); b) animals (the minor source), and c) microorganisms (fungi, bacteria, algae), which decompose the primary plant and animal material, and synthesize the major part of soil carbohydrates. A particular soil sample provides a momentary glimpse into a dynamic system (continuous addition, degradation and synthesis) that might, except for seasonal variations, be in equilibrium. The purpose of this study is to identify and quantify the major sugars in a grass soil and characterize the relationship between their concentration variations and soil microbial behavior over an annual cycle. Soil samples were collected monthly in a ryegrass field close to Corvallis, Oregon, and analyzed by gas chromatography-mass spectrometry as total silylated extracts for sugar composition, and by gas chromatography-flame ionization as fatty acid methyl esters derived from phospholipids and neutral lipids (PLFA and NLFA, respectively). The preliminary results of the first six-month experiment (from January to June, 2004) show that as the ambient temperatures increase the sugar concentrations (glucose, fructose, sucrose and trehalose) also tend to increase in the soil. A decrease is observed in March when precipitation was low during the whole month. The same trend is observed for the active biomass of fungi and bacteria estimated by their fatty acids derived from phospholipids. Fatty acids 18:2ω 6c and 18:3ω 6c are used as fungal biomarkers. Branched (15:0i

  3. Long-term nitrous oxide fluxes in annual and perennial agricultural and unmanaged ecosystems in the upper Midwest USA.

    Science.gov (United States)

    Gelfand, Ilya; Shcherbak, Iurii; Millar, Neville; Kravchenko, Alexandra N; Robertson, G Philip

    2016-11-01

    Differences in soil nitrous oxide (N 2 O) fluxes among ecosystems are often difficult to evaluate and predict due to high spatial and temporal variabilities and few direct experimental comparisons. For 20 years, we measured N 2 O fluxes in 11 ecosystems in southwest Michigan USA: four annual grain crops (corn-soybean-wheat rotations) managed with conventional, no-till, reduced input, or biologically based/organic inputs; three perennial crops (alfalfa, poplar, and conifers); and four unmanaged ecosystems of different successional age including mature forest. Average N 2 O emissions were higher from annual grain and N-fixing cropping systems than from nonleguminous perennial cropping systems and were low across unmanaged ecosystems. Among annual cropping systems full-rotation fluxes were indistinguishable from one another but rotation phase mattered. For example, those systems with cover crops and reduced fertilizer N emitted more N 2 O during the corn and soybean phases, but during the wheat phase fluxes were ~40% lower. Likewise, no-till did not differ from conventional tillage over the entire rotation but reduced emissions ~20% in the wheat phase and increased emissions 30-80% in the corn and soybean phases. Greenhouse gas intensity for the annual crops (flux per unit yield) was lowest for soybeans produced under conventional management, while for the 11 other crop × management combinations intensities were similar to one another. Among the fertilized systems, emissions ranged from 0.30 to 1.33 kg N 2 O-N ha -1  yr -1 and were best predicted by IPCC Tier 1 and ΔEF emission factor approaches. Annual cumulative fluxes from perennial systems were best explained by soil NO3- pools (r 2  = 0.72) but not so for annual crops, where management differences overrode simple correlations. Daily soil N 2 O emissions were poorly predicted by any measured variables. Overall, long-term measurements reveal lower fluxes in nonlegume perennial vegetation and, for

  4. Phosphorus status and microbial community of paddy soil with the growth of annual ryegrass (Lolium multiflorum Lam.) under different phosphorus fertilizer treatments*

    Science.gov (United States)

    Guo, Hai-chao; Wang, Guang-huo

    2009-01-01

    Annual ryegrass (Lolium multiflorum Lam.) was grown in paddy soil in pots under different phosphorus (P) fertilizer treatments to investigate changes of P fractions and microbial community of the soil. The treatments included Kunyang phosphate rock (KPR) applications at 50 mg P/kg (KPR50) and 250 mg P/kg (KPR250), mono-calcium phosphate (MCP) application at 50 mg P/kg (MCP50), and the control without P application. The results showed that KPR50, KPR250, and MCP50 applications significantly increased the dry weight of the ryegrass by 13%, 38%, and 55%, and increased P uptake by 19%, 135%, and 324%, respectively. Compared with MCP50, the relative effectiveness of KPR50 and KPR250 treatments in ryegrass production was about 23% and 68%, respectively. After one season of ryegrass growth, the KPR50, KPR250, and MCP50 applications increased soil-available P by 13.4%, 26.8%, and 55.2%, respectively. More than 80% of the applied KPR-P remained as HCl-P fraction in the soil. Phospholipid fatty acid (PLFA) analysis showed that the total and bacterial PLFAs were significantly higher in the soils with KPR250 and MCP50 treatments compared with KPR50 and control. The latter had no significant difference in the total or bacterial PLFAs. The KPR50, KPR250, and MCP50 treatments increased fungal PLFA by 69%, 103%, and 69%, respectively. Both the principal component analysis and the cluster analysis of the PLFA data suggest that P treatments altered the microbial community composition of the soils, and that P availability might be an important contributor to the changes in the microbial community structure during the ryegrass growth in the paddy soils. PMID:19817001

  5. A Guide to Ordinary High Water Mark (OHWM) Delineation for Non-Perennial Streams in the Western Mountains, Valleys, and Coast Region of the United States

    Science.gov (United States)

    2014-08-01

    38 15 Remotely sensed images acquired from Google Earth and ground-based images from 2011 of a non-perennial stream in Teton County, WY...less confined. Debris flows and landslides are common in the region, accounting for much, if not most, of the sediment flux from headwater streams in...information is becoming in- creasingly available and easy to analyze via free, open-access resources such as Google Earth (www.earth.google.com). Where

  6. A Systematic Review of Perennial Staple Crops Literature Using Topic Modeling and Bibliometric Analysis

    Science.gov (United States)

    2016-01-01

    Research on perennial staple crops has increased in the past ten years due to their potential to improve ecosystem services in agricultural systems. However, multiple past breeding efforts as well as research on traditional ratoon systems mean there is already a broad body of literature on perennial crops. In this review, we compare the development of research on perennial staple crops, including wheat, rice, rye, sorghum, and pigeon pea. We utilized the advanced search capabilities of Web of Science, Scopus, ScienceDirect, and Agricola to gather a library of 914 articles published from 1930 to the present. We analyzed the metadata in the entire library and in collections of literature on each crop to understand trends in research and publishing. In addition, we applied topic modeling to the article abstracts, a type of text analysis that identifies frequently co-occurring terms and latent topics. We found: 1.) Research on perennials is increasing overall, but individual crops have each seen periods of heightened interest and research activity; 2.) Specialist journals play an important role in supporting early research efforts. Research often begins within communities of specialists or breeders for the individual crop before transitioning to a more general scientific audience; 3.) Existing perennial agricultural systems and their domesticated crop material, such as ratoon rice systems, can provide a useful foundation for breeding efforts, accelerating the development of truly perennial crops and farming systems; 4.) Primary research is lacking for crops that are produced on a smaller scale globally, such as pigeon pea and sorghum, and on the ecosystem service benefits of perennial agricultural systems. PMID:27213283

  7. Phosphorus availability to ryegrass from urban sewage sludges assessed by isotopic labeling and dilution technique, effect of irradiation

    International Nuclear Information System (INIS)

    El-Motaium, R.A.; Morel, C.

    2007-01-01

    Urban sewage sludge are widely used as alternative P input because of their high P content. Irradiation of sewage sludge is developed in Egypt to make safe spreading of sludge on agricultural fields. Five sludges were sampled from representative urban wastewater treatment plants located in Cairo, Egypt. Sub samples were irradiated using gamma radiation at 6 KGy dose. A pot experiment was conducted under plastic greenhouse using sandy P-deficient soil. The soil was homogeneously labelled with a radioactive solution of carrier-free 32 PO 4 (about 3 MBq kg / soil) to determine the contribution of the different sources of P in plant nutrition. Sludges were applied at 50 mg P/ kg soil. In addition, a control treatment was also carried out to analyze sludge P availability in comparison to a water soluble mineral fertilizer, i.e. 50 mg P/kg soil was applied as commercial monocalcium phosphate (SSP). A reference treatment was included without any P application but the radioactive solution was added. One gram of ryegrass seeds (Lolium multiflorium) was sown in each pot. The aerial parts of the ryegrass were harvested four times, every 3 weeks. Analysis of all harvests included 32 P and total P content was used to determine the respective contribution of soil and sludge to plant P nutrition and the plant available P (L value) using the isotopic dilution principle. The ratio of radioactive P to non-radioactive P, i.e. isotopic composition, was calculated. The total P content in the different urban sewage sludge was ranged from 6.2 to 13.8 g P/ kg and affected by irradiation. Because the soil was extremely P deficient (L value=0.3 mg P/ kg soil), P derived from seeds represented 99% of the P taken up when no P was applied and 87% when applying 50 mg P-SSP/ kg. After correcting the contribution of ryegrass seeds, sludge P contributed by 98% to plant nutrition and 7.2% of the applied P was recovered. The sludge type and irradiation factors did not significantly affect sludge P

  8. Energy balance and cost-benefit analysis of biogas production from perennial energy crops pretreated by wet oxidation

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Wang, Guangtao; Møller, Henrik B.

    2008-01-01

    Perennial crops need far less energy to plant, require less fertilizer and pesticides, and show a lower negative environmental impact compared with annual crops like for example corn. This makes the cultivation of perennial crops as energy crops more sustainable than the use of annual crops....... The conversion into biogas in anaerobic digestion plants shows however much lower specific methane yields for the raw perennial crops like miscanthus and willow due to their lignocellulosic structure. Without pretreatment the net energy gain is therefore lower for the perennials than for corn. When applying wet...... oxidation to the perennial crops, however, the specific methane yield increases significantly and the ratio of energy output to input and of costs to benefit for the whole chain of biomass supply and conversion into biogas becomes higher than for corn. This will make the use of perennial crops as energy...

  9. Environmental impact of converting Conservation Reserve Program land to perennial bioenergy crops in Illinois.

    Science.gov (United States)

    Blanc-Betes, E.; Hudiburg, T. W.; Khanna, M.; DeLucia, E. H.

    2017-12-01

    Reducing dependence on fossil fuels by the 20% by 2022 mandated by the Energy Independence and Security Act would require 35 billion Ga of ethanol and the loss of 9 to 12 Mha of food producing land to biofuel production, challenging our ability to develop a sustainable bioenergy source while meeting the food demands of a growing population. There are currently 8.5 Mha of land enrolled in the Conservation Reserve Program (CRP), a US government funded program to incentivize the retirement of environmentally sensitive cropland out of conventional crop production. About 63% of CRP land area could potentially be converted to energy crops, contributing to biofuel targets without displacing food. With high yields and low fertilization and irrigation requirements, perennial cellulosic crops (e.g. switchgrass and Miscanthus) not only would reduce land requirements by up to 15% compared to prairies or corn-based biofuel, but also serve other conservation goals such as C sequestration in soils, and water and air quality improvement. Here, we use the DayCent biogeochemical model to assess the potential of CRP land conversion to switchgrass or Miscanthus to provide a sustainable source of biofuel, reduce GHG emissions and increase soil organic carbon (SOC) storage in the area of Illinois, which at present contributes to 10% of the biofuel production in the US. Model simulations indicate that the replacement of traditional corn-soy rotation with CRP reduces GHG emissions by 3.3 Mg CO2-eq ha-1 y-1 and increases SOC storage at a rate of 0.5 Mg C ha-1 y-1. Conversion of CRP land to cellulosic perennials would further reduce GHG emissions by 1.1 Mg CO2-eq ha-1 y-1 for switchgrass and 6.2 Mg CO2-eq ha-1 y-1 for Miscanthus, and increase C sequestration in soils (1.7 Tg C for switchgrass and 7.7 Tg C for Miscanthus in 30 years). Cellulosic energy crops would increase average annual yields by approximately 5.6 Mg ha-1 for switchgrass and 13.6 Mg ha-1 for Miscanthus, potentially

  10. Bidirectional recovery patterns of Mojave Desert vegetation in an aqueduct pipeline corridor after 36 years: I. Perennial shrubs and grasses

    Science.gov (United States)

    Berry, Kristin H.; Weigand, James F.; Gowan, Timothy A.; Mack, Jeremy S.

    2015-01-01

    We studied recovery of 21 perennial plant species along a severely disturbed aqueduct corridor in a Larrea tridentata-Ambrosia dumosa plant alliance in the Mojave Desert 36 years after construction. The 97-m wide corridor contained a central dirt road and buried aqueduct pipeline. We established transects at 0 m (road verge), 20 m and 40 m into the disturbance corridor, and at 100 m in undisturbed habitat (the control). Although total numbers of shrubs per transect did not vary significantly with distance from the verge, canopy cover of shrubs, species richness, and species diversity were higher in the control than at the verge and other distances. Canopy cover of common shrubs (Ericameria nauseosa, Ambrosia salsola, A. dumosa, L. tridentata, Grayia spinosa) and perennial grasses (Elymus elymoides, Poa secunda) also varied significantly by location. Discriminant analysis clearly separated the four distances based on plant composition. Patterns of recovery were bidirectional: secondary succession from the control into the disturbance corridor and inhibition from the verge in the direction of the control. Time estimated for species composition to resemble the control is dependent on location within the disturbance corridor and could be centuries at the road verge. Our findings have applications to other deserts.

  11. A comparative study of AMF diversity in annual and perennial plant species from semiarid gypsum soils.

    Science.gov (United States)

    Alguacil, M. M.; Torrecillas, E.; Roldán, A.; Díaz, G.; Torres, P.

    2012-04-01

    The arbuscular mycorrhizal fungi (AMF) communities composition regulate plant interactions and determine the structure of plant communities. In this study we analysed the diversity of AMF in the roots of two perennial gypsophyte plant species, Herniaria fruticosa and Senecio auricula, and an annual herbaceous species, Bromus rubens, growing in a gypsum soil from a semiarid area. The objective was to determine whether perennial and annual host plants support different AMF communities in their roots and whether there are AMF species that might be indicators of specific functional plant roles in these ecosystems. The roots were analysed by nested PCR, cloning, sequencing of the ribosomal DNA small subunit region and phylogenetic analysis. Twenty AMF sequence types, belonging to the Glomus group A, Glomus group B, Diversisporaceae, Acaulosporaceae, Archaeosporaceae and Paraglomeraceae, were identified. Both gypsophyte perennial species had differing compositions of the AMF community and higher diversity when compared with the annual species, showing preferential selection by specific AMF sequences types. B. rubens did not show host specificity, sharing the full composition of its AMF community with both perennial plant species. Seasonal variations in the competitiveness of AM fungi could explain the observed differences in AMF community composition, but this is still a working hypothesis that requires the analysis of further data obtained from a higher number of both annual and perennial plant species in order to be fully tested.

  12. Cloning and sequencing of Lol pI, the major allergenic protein of rye-grass pollen.

    Science.gov (United States)

    Griffith, I J; Smith, P M; Pollock, J; Theerakulpisut, P; Avjioglu, A; Davies, S; Hough, T; Singh, M B; Simpson, R J; Ward, L D

    1991-02-25

    We have isolated a full length cDNA clone encoding the major glycoprotein allergen Lol pI. The clone was selected using a combination of immunological screening of a cDNA expression library and PCR amplification of Lol pI-specific transcripts. Lol pI expressed in bacteria as a fusion protein shows recognition by specific IgE antibodies present in sera of grass pollen-allergic subjects. Northern analysis has shown that the Lol pI transcripts are expressed only in pollen of rye-grass. Molecular cloning of Lol pI provides a molecular genetic approach to study the structure-function relationship of allergens.

  13. Diffusive gradient in thin FILMS (DGT) compared with soil solution and labile uranium fraction for predicting uranium bioavailability to ryegrass.

    Science.gov (United States)

    Duquène, L; Vandenhove, H; Tack, F; Van Hees, M; Wannijn, J

    2010-02-01

    The usefulness of uranium concentration in soil solution or recovered by selective extraction as unequivocal bioavailability indices for uranium uptake by plants is still unclear. The aim of the present study was to test if the uranium concentration measured by the diffusive gradient in thin films (DGT) technique is a relevant substitute for plant uranium availability in comparison to uranium concentration in the soil solution or uranium recovered by ammonium acetate. Ryegrass (Lolium perenne L. var. Melvina) is grown in greenhouse on a range of uranium spiked soils. The DGT-recovered uranium concentration (C(DGT)) was correlated with uranium concentration in the soil solution or with uranium recovered by ammonium acetate extraction. Plant uptake was better predicted by the summed soil solution concentrations of UO(2)(2+), uranyl carbonate complexes and UO(2)PO(4)(-). The DGT technique did not provide significant advantages over conventional methods to predict uranium uptake by plants. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Diffusive gradient in thin FILMS (DGT) compared with soil solution and labile uranium fraction for predicting uranium bioavailability to ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Duquene, L. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium); Vandenhove, H., E-mail: hvandenh@sckcen.b [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium); Tack, F. [Ghent University, Laboratory for Analytical Chemistry and Applied Ecochemistry, Coupure Links 653, B-9000 Gent (Belgium); Van Hees, M.; Wannijn, J. [SCK-CEN, Biosphere Impact Studies, Boeretang 200, B-2400 Mol (Belgium)

    2010-02-15

    The usefulness of uranium concentration in soil solution or recovered by selective extraction as unequivocal bioavailability indices for uranium uptake by plants is still unclear. The aim of the present study was to test if the uranium concentration measured by the diffusive gradient in thin films (DGT) technique is a relevant substitute for plant uranium availability in comparison to uranium concentration in the soil solution or uranium recovered by ammonium acetate. Ryegrass (Lolium perenne L. var. Melvina) is grown in greenhouse on a range of uranium spiked soils. The DGT-recovered uranium concentration (C{sub DGT}) was correlated with uranium concentration in the soil solution or with uranium recovered by ammonium acetate extraction. Plant uptake was better predicted by the summed soil solution concentrations of UO{sub 2}{sup 2+}, uranyl carbonate complexes and UO{sub 2}PO{sub 4}{sup -}. The DGT technique did not provide significant advantages over conventional methods to predict uranium uptake by plants.

  15. Diffusive gradient in thin FILMS (DGT) compared with soil solution and labile uranium fraction for predicting uranium bioavailability to ryegrass

    International Nuclear Information System (INIS)

    Duquene, L.; Vandenhove, H.; Tack, F.; Van Hees, M.; Wannijn, J.

    2010-01-01

    The usefulness of uranium concentration in soil solution or recovered by selective extraction as unequivocal bioavailability indices for uranium uptake by plants is still unclear. The aim of the present study was to test if the uranium concentration measured by the diffusive gradient in thin films (DGT) technique is a relevant substitute for plant uranium availability in comparison to uranium concentration in the soil solution or uranium recovered by ammonium acetate. Ryegrass (Lolium perenne L. var. Melvina) is grown in greenhouse on a range of uranium spiked soils. The DGT-recovered uranium concentration (C DGT ) was correlated with uranium concentration in the soil solution or with uranium recovered by ammonium acetate extraction. Plant uptake was better predicted by the summed soil solution concentrations of UO 2 2+ , uranyl carbonate complexes and UO 2 PO 4 - . The DGT technique did not provide significant advantages over conventional methods to predict uranium uptake by plants.

  16. Phenotypic plasticity despite source-sink population dynamics in a long-lived perennial plant.

    Science.gov (United States)

    Anderson, Jill T; Sparks, Jed P; Geber, Monica A

    2010-11-01

    • Species that exhibit adaptive plasticity alter their phenotypes in response to environmental conditions, thereby maximizing fitness in heterogeneous landscapes. However, under demographic source-sink dynamics, selection should favor traits that enhance fitness in the source habitat at the expense of fitness in the marginal habitat. Consistent with source-sink dynamics, the perennial blueberry, Vaccinium elliottii (Ericaceae), shows substantially higher fitness and population sizes in dry upland forests than in flood-prone bottomland forests, and asymmetrical gene flow occurs from upland populations into bottomland populations. Here, we examined whether this species expresses plasticity to these distinct environments despite source-sink dynamics. • We assessed phenotypic responses to a complex environmental gradient in the field and to water stress in the glasshouse. • Contrary to expectations, V. elliottii exhibited a high degree of plasticity in foliar and root traits (specific leaf area, carbon isotope ratios, foliar nitrogen content, root : shoot ratio, root porosity and root architecture). • We propose that plasticity can be maintained in source-sink systems if it is favored within the source habitat and/or a phylogenetic artifact that is not costly. Additionally, plasticity could be advantageous if habitat-based differences in fitness result from incipient niche expansion. Our results illuminate the importance of evaluating phenotypic traits and fitness components across heterogeneous landscapes. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

  17. Transcriptome resources for the perennial sunflower Helianthus maximiliani obtained from ecologically divergent populations.

    Science.gov (United States)

    Kawakami, Takeshi; Darby, Brian J; Ungerer, Mark C

    2014-07-01

    Next-generation sequencing (NGS) technologies provide a rapid means to generate genomic resources for species exhibiting interesting ecological and evolutionary variation but for which such resources are scant or nonexistent. In the current report, we utilize 454 pyrosequencing to obtain transcriptome information for multiple individuals and tissue types from geographically disparate and ecologically differentiated populations of the perennial sunflower species Helianthus maximiliani. A total of 850 275 raw reads were obtained averaging 355 bp in length. Reads were assembled, postprocessing, into 16 681 unique contigs with an N50 of 898 bp and a total length of 13.6 Mb. A majority (67%) of these contigs were annotated based on comparison with the Arabidopsis thaliana genome (TAIR10). Contigs were identified that exhibit high similarity to genes associated with natural variation in flowering time and freezing tolerance in other plant species and will facilitate future studies aimed at elucidating the molecular basis of clinal life history variation and adaptive differentiation in H. maximiliani. Large numbers of gene-associated simple sequence repeats (SSRs) and single-nucleotide polymorphisms (SNPs) also were identified that can be deployed in mapping and population genomic analyses. © 2014 John Wiley & Sons Ltd.

  18. The Perennial Debate: Nature, Nurture, or Choice? Black and White Americans' Explanations for Individual Differences

    Science.gov (United States)

    Jayaratne, Toby Epstein; Gelman, Susan A.; Feldbaum, Merle; Sheldon, Jane P.; Petty, Elizabeth M.; Kardia, Sharon L.R.

    2009-01-01

    This paper examines three common explanations for human characteristics: genes, the environment, and choice. Based on data from a representative sample of White and Black Americans, respondents indicated how much they believed each factor influenced individual differences in athleticism, nurturance, drive, math ability, violence, intelligence, and sexual orientation. Results show that across traits: 1) Black respondents generally favor choice and reject genetic explanations, whereas White respondents indicate less causal consistency; 2) although a sizeable subset of respondents endorse just one factor, most report multiple factors as at least partly influential; and 3) among White respondents greater endorsement of genetic explanations is associated with less acceptance of choice and the environment, although among Black respondents a negative relationship holds only between genes and choice. The social relevance of these findings is discussed within the context of the attribution, essentialism and lay theory literature. The results underscore the need to consider more complex and nuanced issues than are implied by the simplistic, unidimensional character of the nature/nurture and determinism/free will debates — perennial controversies that have significance in the current genomic era. PMID:20072661

  19. Effect of decabromodiphenyl ether (BDE-209) on a soil-biota system: Role of earthworms and ryegrass.

    Science.gov (United States)

    Feng, Mingbao; He, Qun; Shi, Jiaqi; Qin, Li; Zhang, Xuesheng; Sun, Ping; Wang, Zunyao

    2016-06-01

    In the present study, the toxic effect of decabromodiphenyl ether (BDE-209), an important brominated fire retardant, on soil was evaluated by amending with different concentrations (0 mg/kg, 1 mg/kg, 10 mg/kg, and 500 mg/kg dry wt) for 40 d. The activities of 3 soil enzymes (urease, catalase, and alkaline phosphatase) were measured as the principal assessment endpoints. Meanwhile, the effects of natural environmental factors, such as light conditions and soil biota, on BDE-209 intoxication were studied. For the latter, 30 earthworms (Metaphire guillelmi) with fully matured clitella or ryegrass (Lolium perenne) with fully matured leaves were exposed in soil amended with BDE-209. The activities of the soil enzymes were adversely affected by BDE-209, especially for the high-concentration treatments, with greater adverse effects in the dark than in the light. The presence of earthworms reduced toxicity to BDE-209, whereas ryegrass did not. The calculated integrated biomarker response index, which provides a general indicator of the health status of test species by combining different biomarker signals, further validated these findings. Moreover, the antioxidant status (oxidant-antioxidant balance) of these 2 biota was assessed. Results indicated that BDE-209 significantly affected the activities of antioxidant enzymes (superoxide dismutase and catalase) and enhanced the levels of malondialdehyde in both species. The present study may facilitate a better understanding of the toxicity of BDE-209 toward the soil environment. Environ Toxicol Chem 2016;35:1349-1357. © 2015 SETAC. © 2015 SETAC.

  20. Introducing perennial biomass crops into agricultural landscapes to address water quality challenges and provide other environmental services: Integrating perennial bioenergy crops into agricultural landscapes

    Energy Technology Data Exchange (ETDEWEB)

    Cacho, J. F. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Negri, M. C. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Zumpf, C. R. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA; Campbell, P. [Environmental Science Division, Argonne National Laboratory, Lemont IL USA

    2017-11-29

    The world is faced with a difficult multiple challenge of meeting nutritional, energy, and other basic needs, under a limited land and water budget, of between 9 and 10 billion people in the next three decades, mitigating impacts of climate change, and making agricultural production resilient. More productivity is expected from agricultural lands, but intensification of production could further impact the integrity of our finite surface water and groundwater resources. Integrating perennial bioenergy crops in agricultural lands could provide biomass for biofuel and potential improvements on the sustainability of commodity crop production. This article provides an overview of ways in which research has shown that perennial bioenergy grasses and short rotation woody crops can be incorporated into agricultural production systems with reduced indirect land use change, while increasing water quality benefits. Current challenges and opportunities as well as future directions are also highlighted.

  1. Comparison of Mometasone Furoate Monohydrate (Nasonex and Fluticasone Propionate (Flixonase Nasal Sprays in the Treatment of Dust Mite-sensitive Children with Perennial Allergic Rhinitis

    Directory of Open Access Journals (Sweden)

    Ka-Kit Mak

    2013-08-01

    Conclusion: Following the 4-week therapy, MFM provided greater improvement compared to FP for symptoms of childhood perennial-allergic rhinitis. Based on their TSSs, the MFM group experienced more effective relief of nasal symptoms, whereas the FP group experienced more effective relief of non-nasal symptoms.

  2. Perennial peanut (Arachis glabrata Benth.) contains polyphenol oxidase (PPO) and PPO substrates that can reduce post-harvest proteolysis.

    Science.gov (United States)

    Sullivan, Michael L; Foster, Jamie L

    2013-08-15

    Studies of perennial peanut (Arachis glabrata Benth.) suggest its hay and haylage have greater levels of rumen undegraded protein (RUP) than other legume forages such as alfalfa (Medicago sativa L.). Greater RUP can result in more efficient nitrogen utilization by ruminant animals with positive economic and environmental effects. We sought to determine whether, like red clover (Trifolium pretense L.), perennial peanut contains polyphenol oxidase (PPO) and PPO substrates that might be responsible for increased RUP. Perennial peanut extracts contain immunologically detectible PPO protein and high levels of PPO activity (>100 nkatal mg(-1) protein). Addition of caffeic acid (PPO substrate) to perennial peanut extracts depleted of endogenous substrates reduced proteolysis by 90%. Addition of phenolics prepared from perennial peanut leaves to extracts of either transgenic PPO-expressing or control (non-expressing) alfalfa showed peanut phenolics could reduce proteolysis >70% in a PPO-dependent manner. Two abundant likely PPO substrates are present in perennial peanut leaves including caftaric acid. Perennial peanut contains PPO and PPO substrates that together are capable of inhibiting post-harvest proteolysis, suggesting a possible mechanism for increased RUP in this forage. Research related to optimizing the PPO system in other forage crops will likely be applicable to perennial peanut. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  3. Energy balance and cost-benefit analysis of biogas production from perennial energy crops pretreated by wet oxidation

    DEFF Research Database (Denmark)

    Uellendahl, Hinrich; Wang, Guangtao; Møller, H.B.

    2008-01-01

    . The conversion into biogas in anaerobic digestion plants shows however much lower specific methane yields for the raw perennial crops like miscanthus and willow due to their lignocellulosic structure. Without pretreatment the net energy gain is therefore lower for the perennials than for corn. When applying wet...

  4. Nutrients can enhance the abundance and expression of alkane hydroxylase CYP153 gene in the rhizosphere of ryegrass planted in hydrocarbon-polluted soil.

    Directory of Open Access Journals (Sweden)

    Muhammad Arslan

    Full Text Available Plant-bacteria partnership is a promising strategy for the remediation of soil and water polluted with hydrocarbons. However, the limitation of major nutrients (N, P and K in soil affects the survival and metabolic activity of plant associated bacteria. The objective of this study was to explore the effects of nutrients on survival and metabolic activity of an alkane degrading rhizo-bacterium. Annual ryegrass (Lolium multiflorum was grown in diesel-contaminated soil and inoculated with an alkane degrading bacterium, Pantoea sp. strain BTRH79, in greenhouse experiments. Two levels of nutrients were applied and plant growth, hydrocarbon removal, and gene abundance and expression were determined after 100 days of sowing of ryegrass. Results obtained from these experiments showed that the bacterial inoculation improved plant growth and hydrocarbon degradation and these were further enhanced by nutrients application. Maximum plant biomass production and hydrocarbon mineralization was observed by the combined use of inoculum and higher level of nutrients. The presence of nutrients in soil enhanced the colonization and metabolic activity of the inoculated bacterium in the rhizosphere. The abundance and expression of CYP153 gene in the rhizosphere of ryegrass was found to be directly associated with the level of applied nutrients. Enhanced hydrocarbon degradation was associated with the population of the inoculum bacterium, the abundance and expression of CYP153 gene in the rhizosphere of ryegrass. It is thus concluded that the combination between vegetation, inoculation with pollutant-degrading bacteria and nutrients amendment was an efficient approach to reduce hydrocarbon contamination.

  5. Selenium bioavailability and uptake as affected by four different plants in a loamy clay soil with particular attention to mycorrhizae inoculated ryegrass

    International Nuclear Information System (INIS)

    Munier-Lamy, C.; Deneux-Mustin, S.; Mustin, C.; Merlet, D.; Berthelin, J.; Leyval, C.

    2007-01-01

    The aim of this study was to investigate the influence of plant species, especially of their rhizosphere soil, and of inoculation with an arbuscular mycorrhizal (AM) fungus on the bioavailability of selenium and its transfer in soil-plant systems. A pot experiment was performed with a loamy clay soil and four plant species: maize, lettuce, radish and ryegrass, the last one being inoculated or not with an arbuscular mycorrhizal fungus (Glomus mosseae). Plant biomass and Se concentration in shoots and roots were estimated at harvest. Se bioavailability in rhizosphere and unplanted soil was evaluated using sequential extractions. Plant biomass and selenium uptake varied with plant species. The quantity of rhizosphere soil also differed between plants and was not proportional to plant biomass. The highest plant biomass, Se concentration in plants, and soil to plant transfer factor were obtained with radish. The lowest Se transfer factors were obtained with ryegrass. For the latter, mycorrhizal inoculation did not significantly affect plant growth, but reduced selenium transfer from soil to plant by 30%. In unplanted soil after 65 days aging, more than 90% of added Se was water-extractable. On the contrary, Se concentration in water extracts of rhizosphere soil represented less than 1% and 20% of added Se for ryegrass and maize, respectively. No correlation was found between the water-extractable fraction and Se concentration in plants. The speciation of selenium in the water extracts indicated that selenate was reduced, may be under organic forms, in the rhizosphere soil

  6. Accurate Determination of Platinum, Palladium, and Rhodium in Ryegrass using Collision Cell Inductively Coupled Plasma Mass Spectrometry with Xenon as Collision Gas

    International Nuclear Information System (INIS)

    Amr, M.A.

    2011-01-01

    Inductively coupled plasma mass spectrometry with an octupole collision cell was used for determination of Pt, Pd and Rh in ryegrass (Lolium multiflorum) which was grown hydroponically. Xenon was used as a collision gas to reduce serious polyatomic interferences formed by combination of matrix elements such as CI, Cu, Hf, Sr, Zn, Zr, Y and REE with O, N, C, and Ar. The detection limits for Pt, Pd and Rh in spiked ryegrass are 1.8, 4.2, and 0.8 ppt, respectively. The results for Pt, Pd and Rh in reference materials (NIST SRM 2557, recycled monolith auto catalyst) are in agreement with the certified values. The bioaccumulation of Pt, Pd and Rh by ryegrass grown hydroponically with nutrient solutions containing Pt, Pd and Rh was studied. The obtained results showed that most of the studied metals were accumulated in roots, and only a small fraction was metabolized and transported to leaves. The highest bioaccumulation factors were obtained for Pd and Rh in roots and for Pt in leaves

  7. Comparison of signaling interactions determining annual and perennial plant growth in response to low temperature

    Directory of Open Access Journals (Sweden)

    Astrid eWingler

    2015-01-01

    Full Text Available Low temperature inhibits plant growth despite the fact that considerable rates of photosynthetic activity can be maintained. Instead of lower rates of photosynthesis, active inhibition of cell division and expansion is primarily responsible for reduced growth. This results in sink limitation and enables plants to accumulate carbohydrates that act as compatible solutes or are stored throughout the winter to enable re-growth in spring. Regulation of growth in response to temperature therefore requires coordination with carbon metabolism, e.g. via the signaling metabolite trehalose-6-phosphate. The phytohormones gibberellins (GA and jasmonate (JA play an important role in regulating growth in response to temperature. Growth restriction at low temperature is mainly mediated by DELLA proteins, whose degradation is promoted by GA. For annual plants, it has been shown that the GA/DELLA pathway interacts with JA signaling and C-repeat binding factor (CBF dependent cold acclimation, but these interactions have not been explored in detail for perennials. Growth regulation in response to seasonal factors is, however, particularly important in perennials, especially at high latitudes. In autumn, growth cessation in trees is caused by shortening of the daylength in interaction with phytohormone signaling. In perennial grasses seasonal differences in the sensitivity to GA may enable enhanced growth in spring. This review provides an overview of the signaling interactions that determine plant growth at low temperature and highlights gaps in our knowledge, especially concerning the seasonality of signaling responses in perennial plants.

  8. Returning succession to downy brome dominated rangelands: roadblocks to perennial grass establishment

    Science.gov (United States)

    The most common cause of successional retrogression in the Great Basin is wildfires fueled by downy brome (Bromus tectorum). Downy brome invasion has reduced fire intervals from an estimated 60-100 years down to 5-10 years. Our previous research found that establishment of long-lived perennial grass...

  9. Optimal prescribed burn frequency to manage foundation California perennial grass species and enhance native flora

    Science.gov (United States)

    Grasslands can be diverse assemblages of grasses and forbs but not much is known how perennial grass species management affects native plant diversity except for in a few instances. We studied the use of late spring prescribed burns over a span of eleven years on experimental plots in which the pere...

  10. Next steps in determining the overall sustainability of perennial bioenergy crops

    Science.gov (United States)

    Perennial bioenergy crops are being developed and evaluated in the United States to partially offset petroleum transport fuels. Accurate accounting of upstream and downstream greenhouse gas (GHG) emissions is necessary to measure the overall carbon intensity of new biofuel feedstocks. For example, c...

  11. Theoretical implications for the estimation of dinitrogen fixation by large perennial plant species using isotope dilution

    Science.gov (United States)

    Dwight D. Baker; Maurice Fried; John A. Parrotta

    1995-01-01

    Estimation of symbiotic N2 fixation associated with large perennial plant species, especially trees, poses special problems because the process must be followed over a potentially long period of time to integrate the total amount of fixation. Estimations using isotope dilution methodology have begun to be used for trees in field studies. Because...

  12. Perennial soybean seeds coated with high doses of boron and zinc ...

    African Journals Online (AJOL)

    The objective of this work was to study combinations of high doses of boron (B) and zinc (Zn) in the recoating of perennial soybean seeds, in order to provide these nutrients to the future plants. The physical, physiological and nutritional characteristics of the coated seeds and initial development of plants in a greenhouse ...

  13. Perennial forbs for wildlife habitat restoration on mined lands in the northern Great Plains

    Science.gov (United States)

    Ardell J. Bjugstad; Warren C. Whitman

    1982-01-01

    Research was designed to assess the establishment and growth potential of 30 perennial forbs by seeding and/or transplanting them on coal mine spoil materials over a 2-year period. Five species showed exceptional emergence and vigorous growth from direct seeding. Six species showed vigorous growth with the use of transplanted plants. Seeding resulted in successful...

  14. Energy-conserving perennial agriculture for marginal land in southern Appalachia. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G.

    1982-01-30

    USDA economists predict the end of surplus farm production in the US within this decade. More and more marginal land will be cropped to provide feed for the growing world population and to produce energy. Much of this potential cropland in Southern Appalachia is poorly suited to annual crops, such as corn. Perennial crops are much better suited to steep, rocky, and wet sites. Research was undertaken on the theoretical potentials of perennial species with high predicted yields of protein, carbohydrates, or oils. Several candidate staple perennial crops for marginal land in Southern Appalachia were identified, and estimates were made of their yields, energy input requirements, and general suitabilities. Cropping systems incorporating honeylocust, persimmon, mulberry, jujube, and beech were compared with corn cropping systems. It appears that these candidate staple perennials show distinct advantages for energy conservation and environmental preservation. Detailed economic analyses must await actual demonstration trials, but preliminary indications for ethanol conversion systems with honeylocust are encouraging. It is suggested that short-term loans to farmers undertaking this new type of agriculture would be appropriate to solve cash-flow problems.

  15. Molecular mechanisms responsive to dehydration may impact the invasiveness of perennial weeds under global climate change

    Science.gov (United States)

    Leafy spurge is an invasive perennial weed in the great plains of the US and Canada. The ability of this herbaceous weed to regenerate new shoot growth from an abundance of crown and root buds after severe abiotic stress is critical for survival. Due to its adaptable and aggressive nature, global cl...

  16. Gene Flow in Genetically Engineered Perennial Grasses: Lessons for Modification of Dedicated Bioenergy Crops

    Science.gov (United States)

    Genetic modification of dedicated bioenergy crops, such as switchgrass, will play a major role in crop improvement for a wide range of beneficial traits specific to biofuels. One obstacle that arises regarding transgenic improvement of perennials used for biofuels is the propensity of these plants t...

  17. Changes of biomass in some perennial grass species. | M.C. ...

    African Journals Online (AJOL)

    Patterns of seasonal herbaceous biomass change in a burned, ungrazed savanna woodland are reported. A standard clipping technique was used and material farmed in the current season was separated from that formed in the previous season for three perennial grass species: Brachiaria nigropedata, Andropogon ...

  18. Nitrogen cycling in summer active perennial grass systems in South Australia: Non-symbiotic nitrogen fixation

    NARCIS (Netherlands)

    Gupta, V.V.S.R.; Kroker, S.J.; Hicks, M.; Davoren, W.; Descheemaeker, K.K.E.; Llewellyn, R.

    2014-01-01

    Non-symbiotic nitrogen (N2) fixation by diazotrophic bacteria is a potential source for biological N inputs in non-leguminous crops and pastures. Perennial grasses generally add larger quantities of above- and belowground plant residues to soil, and so can support higher levels of soil biological

  19. Extending the shelf life of flower bulbs and perennials in consumer packages by modiefied atmosphere packaging

    NARCIS (Netherlands)

    Gude, H.; Dijkema, M.H.G.E.; Miller, C.T.

    2011-01-01

    The quality of flower bulbs and herbaceous perennials in consumer packages declines rapidly due to sprouting and drying out. The present study was undertaken to develop Modified Atmosphere Packages (MAP) with suitable filling materials for a prolonged shelf life of different species of flower bulbs

  20. Defining perennial, intermittent and ephemeral channels in eastern Kentucky: application to forestry best management practices

    Science.gov (United States)

    J. R. Svec; R. K. Kolka; J. W. Stringer

    2003-01-01

    In Kentucky stream classification is used to determine which forestry best management practice (BMP) to apply in riparian zones. Kentucky defines stream classes as follows (Stringer and others 1998): a) perennial streams that hold water throughout the year, b) intermittent streams that hold water during wet portions of the year, and c) ephemeral channels that hold...

  1. The central and eastern Arabian Sea as a perennial source of atmospheric carbon dioxide

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; DileepKumar, M.; George, M.D.

    circulation and biological production. In all seasons, the pCO sub(2) is higher in surface waters of the Arabian Sea, except along the Indian coast in the southwest monsoon, than that in atmosphere, and thus this region appears to be a perennial source...

  2. Nitrous oxide emission and soil carbon sequestration from herbaceous perennial biofuel feedstocks

    Science.gov (United States)

    Greenhouse gas (GHG) mitigation and renewable, domestic fuels are needed in the United States. Switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman) are potential bioenergy feedstocks that may meet this need. However, managing perennial grasses for feedstock requires nitro...

  3. Evaluating winter/spring seeding of a native perennial bunchgrass in the sagebrush steppe

    Science.gov (United States)

    Sagebrush (Artemisia tridentata Nutt.) plant communities in the US Great Basin region are being severely impacted by increasingly frequent wildfires in association with the expansion of exotic annual grasses. Maintenance of native perennial bunchgrasses is key to controlling annual grass expansion,...

  4. Patterns of chasmogamy and cleistogamy, a mixed-mating strategy in an endangered perennial.

    Science.gov (United States)

    Koontz, Stephanie M; Weekley, Carl W; Haller Crate, Sarah J; Menges, Eric S

    2017-11-01

    Cleistogamy (CL) in angiosperms historically has been understudied; however, its co-occurrence with chasmogamy (CH) across many plant species suggests a fitness advantage to maintaining this mixed-mating strategy. Maintenance of mixed-mating has been attributed to reproductive assurance, resource allocation or genetic trade-offs. Our goals were to explore patterns of CH and CL, quantify reproductive contributions measured by fruit production and determine how CL is maintained in the endangered perennial Polygala lewtonii. This species exhibits CH and both above-ground cleistogamy (CL-AG) and below-ground cleistogamy (CL-BG). In monthly censuses from 2008 to 2012, we documented flowering patterns by counting CH flowering stems, CL-AG fruits and CL-BG rhizomes per plant. Monitoring of buds on CH flowering stems in 2004 provided an estimate of CH fruits per plant. Plant excavations in 2005 of CL-BG rhizomes provided an estimate of CL-BG fruits per plant. Floral morphs were temporally separated with CH flowers observed from January to May and CL flowers from June to February. Overall, 17.5 % of plants flowered; most plants expressed CH first in spring months (63.4 %) and the rest initiated CL-AG in fall months. Reproductive output was dominated by CH (median 26 fruits) compared to combined CL (median 3.5 fruits). Annual reproductive effort of CL-AG was positively correlated with plant age while CH had no relation. Our research shows CH as the dominant form of reproductive effort with most individuals expressing CH and through greater reproductive contributions. CL appears limited by plant size or resources based on the positive relationship with plant age. CL dependency on resource availability is common in other species found in dry or low-quality habitats; however, CL contributions in this species are comparatively low. This raises more questions related to energy requirements of both floral morphs, how this affects the production of viable progeny and why CL

  5. Genetic resources of perennial forage grasses in Serbia: Current state, broadening and evaluation

    Directory of Open Access Journals (Sweden)

    Sokolović Dejan

    2017-01-01

    Full Text Available Due to historical background of vegetation development, geographical position, climate and relief, Serbia represents one of the 158 world biodiversity centres, based upon the number of plant species and territory size (biodiversity index 0.72. Large areas in Serbia are under natural grasslands and pastures, composed of forage grass species, and important as source of natural plant genetic diversity and germplasm for breeding. These eco-systems represent basic prerequisites for sustainable forage production, but very low potential of them is utilized and genetic resources are not protected. Family Poaceae is present in Serbia flora with 70 genera and among them from the aspect of forage production and quality, the most important are perennial Festuca, Lolium, Dactylis, Phleum, Bromus, Arrhenatherum, Poa and Agrostis species. Most of these grasses have been bred in Serbia and lot of cultivars were released. These cultivars contain autochthonous Serbian material and represent great and important resource of genetic variability. Therefore, collecting of new samples which are acclimatised to local eco-geographical conditions and including them in plant ex situ gene bank is of exceptional importance for further utilization in different plant breeding programmes as well as genetic resources protection. These autochthonous populations have natural variability and very often have satisfactory yielding performance in comparison with introduced cultivars, which referred them for direct phenotypic selection for cultivars release. Broadening of forage grasses genotypes collection is permanent objective of Serbian scientists. Collected accessions are being characterized and evaluated for important phenological, morphological and agronomical traits. In this paper genetic resources of forage grass species, their diversity and potentials, state of the grasses gene banks, as well as possibility for breeding of new cultivars has been analysed.

  6. Potential phytoextraction and phytostabilization of perennial peanut on copper-contaminated vineyard soils and copper mining waste.

    Science.gov (United States)

    Andreazza, Robson; Bortolon, Leandro; Pieniz, Simone; Giacometti, Marcelo; Roehrs, Dione D; Lambais, Mácio R; Camargo, Flávio A O

    2011-12-01

    This study sought to evaluate the potential of perennial peanut (Arachis pintoi) for copper phytoremediation in vineyard soils (Inceptisol and Mollisol) contaminated with copper and copper mining waste. Our results showed high phytomass production of perennial peanut in both vineyard soils. Macronutrient uptakes were not negatively affected by perennial peanut cultivated in all contaminated soils. Plants cultivated in Mollisol showed high copper concentrations in the roots and shoots of 475 and 52 mg kg(-1), respectively. Perennial peanut plants showed low translocation factor values for Cu, although these plants showed high bioaccumulation factor (BCF) for both vineyard soils, Inceptisol and Mollisol, with BCF values of 3.83 and 3.24, respectively, being characterized as a copper hyperaccumulator plant in these soils. Copper phytoextraction from Inceptisol soil was the highest for both roots and entire plant biomass, with more than 800 mg kg(-1) of copper in whole plant. The highest potential copper phytoextraction by perennial peanut was in Inceptisol soil with copper removal of 2,500 g ha(-1). Also, perennial peanut showed high potential for copper phytoremoval in copper mining waste and Mollisol with 1,700 and 1,500 g of copper per hectare, respectively. In addition, perennial peanuts characterized high potential for phytoextraction and phytostabilization of copper in vineyard soils and copper mining waste.

  7. Classification of images of wheat, ryegrass and brome grass species at early growth stages using principal component analysis

    Directory of Open Access Journals (Sweden)

    Golzarian Mahmood R

    2011-09-01

    Full Text Available Abstract Wheat is one of the most important crops in Australia, and the identification of young plants is an important step towards developing an automated system for monitoring crop establishment and also for differentiating crop from weeds. In this paper, a framework to differentiate early narrow-leaf wheat from two common weeds from their digital images is developed. A combination of colour, texture and shape features is used. These features are reduced to three descriptors using Principal Component Analysis. The three components provide an effective and significant means for distinguishing the three grasses. Further analysis enables threshold levels to be set for the discrimination of the plant species. The PCA model was evaluated on an independent data set of plants and the results show accuracy of 88% and 85% in the differentiation of ryegrass and brome grass from wheat, respectively. The outcomes of this study can be integrated into new knowledge in developing computer vision systems used in automated weed management.

  8. Estimating the energy requirements and CO{sub 2} emissions from production of the perennial grasses miscanthus, switchgrass and reed canary grass

    Energy Technology Data Exchange (ETDEWEB)

    Bullard, M.; Metcalfe, P.

    2001-07-01

    The perennial grasses miscanthus, reed canary and swithchgrass have attractions as energy crops in the United Kingdom: all have low demand for fertilizer and pesticide, and are harvested annually. Research on energy ratios and carbon ratios of the grasses is reported. A Microsoft Excel-based model was developed (from an ADAS database) and the input calculations and assumptions are explained. The study demonstrated the attractions of theses grasses as a source of fuel. The results agreed with those from a model developed for the SRC.

  9. A Proteomics Sample Preparation Method for Mature, Recalcitrant Leaves of Perennial Plants

    Science.gov (United States)

    Na, Zhang; Chengying, Lao; Bo, Wang; Dingxiang, Peng; Lijun, Liu

    2014-01-01

    Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie). An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants. PMID:25028960

  10. A proteomics sample preparation method for mature, recalcitrant leaves of perennial plants.

    Directory of Open Access Journals (Sweden)

    Deng Gang

    Full Text Available Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie. An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants.

  11. Belowground Water Dynamics Under Contrasting Annual and Perennial Plant Communities in an Agriculturally-Dominated Landscape

    Science.gov (United States)

    Mora, G.; Asbjornsen, H.; Helmers, M. J.; Shepherd, G. W.

    2005-12-01

    The conversion from grasslands and forests to row-crops in the Midwest has affected soil water cycling because plant characteristics are one of the main parameters determining soil storage capacity, infiltration rates, and surface runoff. Little is known, however, about the extent of modification of soil water dynamics under different plant communities. To address this important issue, we are documenting soil water dynamics under contrasting perennial and annual plant communities in an agriculturally-dominated landscape. Measurements of soil moisture and depths of uptake of source water were obtained for six vegetative cover types (corn and soybean field, brome pasture, degraded savanna, restored savanna, and restored prairie) at the Neal Smith National Wildlife Refuge in Prairie City, Iowa. The depths of uptake of soil water were determined on the basis of oxygen isotope composition of soil water and stem water. Measurements were performed once a month during an entire growing season. Preliminary results indicate that soil water present under the different vegetation types show similar profiles with depth during the dry months. Soil water in the upper 5 cm is enriched in oxygen-18 by about 5 per mil relative to soil water at 100 cm. Our preliminary results also indicate that the isotopic composition of stem water from annual plants is typically higher by about 2 per mil relative to that of stem water from perennial plants during the dry period. Whereas the oxygen isotopic composition for corn stem water is -5.49 per mil, that for elm and oak stem water is -7.62 and -7.51 per mil, respectively. The higher isotope values for corn suggest that annual crop plants are withdrawing water from shallower soil horizons relative to perennial plants. Moreover, our preliminary data suggest lower moisture content in soil under annual plant cover. We propose that the presence of deeper roots in the perennial vegetation allows these plants to tap into deeper water sources when

  12. Noncorrelated effects of seed predation and pollination on the perennial herb Ruellia nudiflora remain spatially consistent

    OpenAIRE

    Abdala-Roberts, Luis; Parra-Tabla, Víctor; Salinas-Peba, Luis; Herrera, Carlos M.

    2009-01-01

    By simultaneously manipulating both seed predator and pollinator effects on the perennial herb Ruellia nudiflora at two sites in Yucatan (Mexico), the present study evaluated (1) whether a correlation (interaction) existed between seed predator and pollinator effects on R. nudiflora seed production and (2) whether such an interaction varied geographically. We used three populations per site, and a total of 20 plants per population (N = 120). Groups of five plants wer...

  13. Soil carbon under perennial pastures; benchmarking the influence of pasture age and management

    Science.gov (United States)

    Orgill, Susan E.; Spoljaric, Nancy; Kelly, Georgina

    2015-07-01

    This paper reports baseline soil carbon stocks from a field survey of 19 sites; 8 pairs/triplet in the Monaro region of New South Wales. Site comparisons were selected by the Monaro Farming Systems group to demonstrate the influence of land management on soil carbon, and included: nutrient management, liming, pasture age and cropping history. Soil carbon stocks varied with parent material and with land management. The fertilised (phosphorus) native perennial pasture had a greater stock of soil carbon compared with the unfertilised site; 46.8 vs 40.4 Mg.C.ha to 0.50 m. However, the introduced perennial pasture which had been limed had a lower stock of soil carbon compared with the unlimed site; 62.8 vs 66.7 Mg.C.ha to 0.50 m. There was a greater stock of soil carbon under two of the three younger (35 yr old) pastures. Cropped sites did not have lower soil carbon stocks at all sites; however, this survey was conducted after three years of above average annual rainfall and most sites had been cropped for less than three years. At all sites more than 20% of the total carbon stock to 0.50 m was in the 0.30 to 0.50 m soil layer highlighting the importance of considering this soil layer when investigating the implications of land management on soil carbon. Our baseline data indicates that nutrient management may increase soil carbon under perennial pastures and highlights the importance of perennial pastures for soil carbon sequestration regardless of age.

  14. Energy from biomass: Results of two-years trials on annual and perennial Herba ceous species

    International Nuclear Information System (INIS)

    Angelini, L.; Ceccarini, L.; Oggiano, N.; Bonari, E.

    1994-01-01

    In the framework of the PRisCa Project (Alternative Crops Research Project) a number of germ plasm collections were set up at the Department of Agronomy of the University of Pisa in order to identify annual and perennial herbaceous species utilizable for electric energy production. The first results deriving from trials carried out in 1992-93 are reported. The following species were used: 1) Annual: Sorghum bicolor, Hibiscus cannabinus, Pennisetum americanum, Kochia scoparia. 2) Perennial: Cynara cardunculus, Helianthus tuberosus, Miscantus sinensis, Arundo donax. Almost all species tested were represented by several genotypes. The total amount of species and genotype tested was 16. On all species, main phenological, biometric and productive determinations were performed. The hypothesized final use was intended to be electric power production by direct combustion and/or gasification. In addition, specific calorific value was also determined by adiabatic calorimeter as well as chemical composition of dry matter and ash composition. Species showing high yield potential, both from the quantitative and qualitative point of view, were Sorghum bicolor and Kochia scoparia (among annuals), as well as Miscanthus sinensis and Arundo donax (among perennials). Total dry matter yield ranged from about 23 tha -1 in the annual species to about 56 tha -1 in the perennials. The highest total calorific power obtainable from dry epigeic biomass was measured in Sorghum bicolor and Arundo donax - 4023 Kcal Kg -1 and 4166 Kcal Kg -1 respectively. The preliminary results suggest that vegetable biomass is environmentally-friendly and could contribute significantly to the world energy needs. (author)

  15. PERPHECLIM ACCAF Project - Perennial fruit crops and forest phenology evolution facing climatic changes

    Science.gov (United States)

    Garcia de Cortazar-Atauri, Iñaki; Audergon, Jean Marc; Bertuzzi, Patrick; Anger, Christel; Bonhomme, Marc; Chuine, Isabelle; Davi, Hendrik; Delzon, Sylvain; Duchêne, Eric; Legave, Jean Michel; Raynal, Hélène; Pichot, Christian; Van Leeuwen, Cornelis; Perpheclim Team

    2015-04-01

    Phenology is a bio-indicator of climate evolutions. Measurements of phenological stages on perennial species provide actually significant illustrations and assessments of the impact of climate change. Phenology is also one of the main key characteristics of the capacity of adaptation of perennial species, generating questions about their consequences on plant growth and development or on fruit quality. Predicting phenology evolution and adaptative capacities of perennial species need to override three main methodological limitations: 1) existing observations and associated databases are scattered and sometimes incomplete, rendering difficult implementation of multi-site study of genotype-environment interaction analyses; 2) there are not common protocols to observe phenological stages; 3) access to generic phenological models platforms is still very limited. In this context, the PERPHECLIM project, which is funded by the Adapting Agriculture and Forestry to Climate Change Meta-Program (ACCAF) from INRA (French National Institute of Agronomic Research), has the objective to develop the necessary infrastructure at INRA level (observatories, information system, modeling tools) to enable partners to study the phenology of various perennial species (grapevine, fruit trees and forest trees). Currently the PERPHECLIM project involves 27 research units in France. The main activities currently developed are: define protocols and observation forms to observe phenology for various species of interest for the project; organizing observation training; develop generic modeling solutions to simulate phenology (Phenological Modelling Platform and modelling platform solutions); support in building research projects at national and international level; develop environment/genotype observation networks for fruit trees species; develop an information system managing data and documentation concerning phenology. Finally, PERPHECLIM project aims to build strong collaborations with public

  16. Nasal budesonide offers superior symptom relief in perennial allergic rhinitis in comparison to nasal azelastine.

    Science.gov (United States)

    Stern, M A; Wade, A G; Ridout, S M; Cambell, L M

    1998-10-01

    Allergic rhinitis is usually treated with oral antihistamines or nasal steroids. Topically active nasal antihistamine is a new treatment modality for allergic rhinitis. The efficacy in comparison to well established topical treatment alternatives is not fully known. To compare the efficacy of intranasally administered azelastine to budesonide, at their respectively recommended dosage, on the symptoms of perennial rhinitis patients. A placebo-controlled, randomized, parallel group study was conducted to compare the efficacy and tolerability of intranasal budesonide aqueous suspension (256 microg once daily) with azelastine hydrochloride nasal spray (280 microg twice daily (560 microg/day)) and with placebo in the treatment of perennial allergic rhinitis. The 195 patients (with at least a 2-year history of perennial allergic rhinitis) recorded individual nasal symptom scores, the degree of symptom control achieved and any adverse events experienced over a 2-week baseline period and a 6-week treatment period. Following treatment, the reductions in mean combined and individual nasal symptom scores from baseline values were significantly greater in the budesonide group compared with the placebo group (P < .0001 for all variables except runny nose P = .01). In patients treated with budesonide, there were also significantly larger reductions from baseline values in combined nasal symptom scores (P < .01) and in scores for all individual nasal symptoms (P < or = .05) compared with those treated with azelastine. The reductions from baseline in both combined and individual nasal symptom scores did not differ between azelastine and placebo. The study medications were well tolerated, producing no unexpected or serious treatment-related adverse events. A once-daily dose of 256 microg of intranasal budesonide aqueous suspension is significantly more effective at relieving the symptoms of perennial allergic rhinitis compared with a twice daily dose of 280 microg of azelastine

  17. Use of Plant Growth Regulators to Improve Branching of Herbaceous Perennial Liners

    OpenAIRE

    Grossman, Mara Celeste

    2012-01-01

    The objective of this study is to evaluate the efficacy of PGRs to improve branching during production of herbaceous perennial liners and finished plants. The effects of benzyladenine (BA) on the branching and root and shoot growth of Agastache Clayt. Ex Gronov. 'Purple Hazeâ , Gaura lindheimeri Engelm. & A. Gray 'Siskiyou Pink', Lavandula à intermedia Emeric ex Loisel. 'Provence', Leucanthemum à superbum (Bergmans ex J.W. Ingram) Bergmans ex Kent. 'Snowcap', and Salvia à sylv...

  18. Genetic variation facilitates seedling establishment but not population growth rate of a perennial invader.

    Science.gov (United States)

    Li, Shou-Li; Vasemägi, Anti; Ramula, Satu

    2016-01-01

    Assessing the demographic consequences of genetic variation is fundamental to invasion biology. However, genetic and demographic approaches are rarely combined to explore the effects of genetic variation on invasive populations in natural environments. This study combined population genetics, demographic data and a greenhouse experiment to investigate the consequences of genetic variation for the population fitness of the perennial, invasive herb Lupinus polyphyllus. Genetic and demographic data were collected from 37 L. polyphyllus populations representing different latitudes in Finland, and genetic variation was characterized based on 13 microsatellite loci. Associations between genetic variation and population size, population density, latitude and habitat were investigated. Genetic variation was then explored in relation to four fitness components (establishment, survival, growth, fecundity) measured at the population level, and the long-term population growth rate (λ). For a subset of populations genetic variation was also examined in relation to the temporal variability of λ. A further assessment was made of the role of natural selection in the observed variation of certain fitness components among populations under greenhouse conditions. It was found that genetic variation correlated positively with population size, particularly at higher latitudes, and differed among habitat types. Average seedling establishment per population increased with genetic variation in the field, but not under greenhouse conditions. Quantitative genetic divergence (Q(ST)) based on seedling establishment in the greenhouse was smaller than allelic genetic divergence (F'(ST)), indicating that unifying selection has a prominent role in this fitness component. Genetic variation was not associated with average survival, growth or fecundity measured at the population level, λ or its variability. The study suggests that although genetic variation may facilitate plant invasions by

  19. The role of changing climate in driving the shift from perennial grasses to annual succulents in a Mediterranean saltmarsh

    NARCIS (Netherlands)

    Strain, E.M.A.; van Belzen, J.; Comandini, P.; Wong, J.; Bouma, T.J.; Airoldi, L.

    2017-01-01

    Changing climate threatens the structure and function of saltmarshes, which are often severely degraded by other human perturbations. Along the Mediterranean coastline, increasing temperature and decreasing rainfall have been hypothesised to trigger habitat shifts from perennial grasses to annual

  20. Interference between perennial grassland and Lavandula stoechas subsp. pedunculata seedlings: a case of spatial segregation cause by competition

    Science.gov (United States)

    Sánchez, Ana M.; Peco, Begoña

    2004-07-01

    This paper analyses the relationship between Lavandula stoechas subsp. pedunculata, a common Mediterranean scrub species in central Iberia, and perennial grasslands. While Lavandula gives rise to almost monospecific formations in intermediate and upper hill zones, perennial grasses occupy the low areas. The proposed explanatory hypothesis for this spatial distribution is that the scrub is unable to establish itself in grasslands with heavy spatial occupation. We designed two experiments to test this hypothesis, one which analysed the effect of perennial grass cover on Lavandula establishment, and another which focused on its influence on previously implanted seedling survival and growth, distinguishing the effect of shoot and root interference. The results show negative interference during establishment and later in the use of light and nutrients. This results in a very low overall survival probability, with only 1.4% of seedlings surviving the first growth period. This low success rate explains the existence of a clear spatial segregation between scrub patches and perennial-dominated grasslands.

  1. Persistence of Overseeded Cool-Season Grasses in Bermudagrass Turf

    Directory of Open Access Journals (Sweden)

    Thomas Serensits

    2011-01-01

    Full Text Available Cool-season grass species are commonly overseeded into bermudagrass turf for winter color. When the overseeded grass persists beyond the spring; however, it becomes a weed. The ability of perennial ryegrass, Italian (annual ryegrass, intermediate ryegrass, and hybrid bluegrass to persist in bermudagrass one year after seeding was determined. Perennial ryegrass, intermediate ryegrass, and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally persisted the most one year after seeding, either because of summer survival of plants or because of new germination the following fall. Plant counts one year after seeding were greater in the higher seeding rate treatment compared to the lower seeding treatment rate of perennial ryegrass, suggesting new germination had occurred. Plant counts one year after seeding plots with intermediate ryegrass or Italian ryegrass were attributed primarily to latent germination and not summer survival. Applications of foramsulfuron generally did not prevent overseeded species stand one year after seeding, supporting the conclusion of new germination. Although quality is less with intermediate ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year later.

  2. Prevalence of quinolone resistance genes, copper resistance genes, and the bacterial communities in a soil-ryegrass system co-polluted with copper and ciprofloxacin.

    Science.gov (United States)

    Tuo, Xiaxia; Gu, Jie; Wang, Xiaojuan; Sun, YiXin; Duan, Manli; Sun, Wei; Yin, Yanan; Guo, Aiyun; Zhang, Li

    2018-04-01

    The presence of high concentrations of residual antibiotics and antibiotic resistance genes (ARGs) in soil may pose potential health and environmental risks. This study investigated the prevalence of plasmid-mediated quinolone resistance (PMQR) genes, copper resistance genes (CRGs), and the bacterial communities in a soil-ryegrass pot system co-polluted with copper and ciprofloxacin (CIP; 0, 20, or 80 mg kg -1 dry soil). Compared with the samples on day 0, the total relative abundances of the PMQR genes and mobile genetic elements (MGEs) were reduced significantly by 80-89% in the ryegrass and soil by the cutting stage (after 75 days). The abundances of PMQR genes and MGEs were reduced by 63-81% in soil treated with 20 mg kg -1 CIP compared with the other treatments, but the abundances of CRGs increased by 18-42%. The presence of 80 mg kg -1 CIP affected the microbial community structure in the soil by increasing the abundances of Acidobacteria and Thaumarchaeota, but decreasing those of Firmicutes. Redundancy analysis indicated that the pH and microbial composition were the main factors that affected the variations in PMQR genes, MGEs, and CRGs, where they could explain 42.2% and 33.3% of the variation, respectively. Furthermore, intI2 may play an important role in the transfer of ARGs. We found that 80 mg kg -1 CIP could increase the abundances of ARGs and CRGs in a soil-ryegrass pot system. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Effects of ewes grazing sulla or ryegrass pasture for different daily durations on forage intake, milk production and fatty acid composition of cheese.

    Science.gov (United States)

    Bonanno, A; Di Grigoli, A; Mazza, F; De Pasquale, C; Giosuè, C; Vitale, F; Alabiso, M

    2016-12-01

    Sulla (Sulla coronarium L.) forage is valued for its positive impact on ruminant production, in part due to its moderate content of condensed tannin (CT). The duration of daily grazing is a factor affecting the feed intake and milk production of ewes. In this study, the effects of grazing sulla pasture compared with annual ryegrass, and the extension of grazing from 8 to 22 h/day, were evaluated with regard to ewe forage intake and milk production, as well as the physicochemical properties and fatty acid (FA) composition of cheese. During 42 days in the spring, 28 ewes of the Comisana breed were divided into four groups (S8, S22, R8 and R22) that grazed sulla (S) or ryegrass (R) for 8 (0800 to 1600 h) or 22 h/day, and received no feeding supplement. In six cheese-making sessions, cheeses were manufactured from the 48 h bulk milk of each group. Compared with ewes grazing ryegrass, those grazing sulla had higher dry matter (DM) intake, intake rate and milk yield, and produced milk that was lower in fat and higher in casein. Ewes grazing for 22 h spent more time eating, which reduced the intake rate, increased DM and nutrient intake and milk yield, and reduced milk fat. Due to the ability of CT to inhibit the complete ruminal biohydrogenation of polyunsaturated fatty acids (PUFA), the FA composition of sulla cheese was more beneficial for consumer health compared with ryegrass cheese, having lower levels of saturated fatty acids and higher levels of PUFA and n-3 FA. The FA profile of S8 cheese was better than that of S22 cheese, as it was higher in branched-chain FA, monounsaturated FA, PUFA, rumenic acid (c9,t11-C18:2), and had a greater health-promoting index. The effect of short grazing time on sulla was attributed to major inhibition of PUFA biohydrogenating ruminal bacteria, presumably stimulated by the higher accumulation of sulla CT in the rumen, which is related to a higher intake rate over a shorter eating time. Thus, grazing sulla improved the performance of

  4. Non-ionic Surfactants and Non-Catalytic Protein Treatment on Enzymatic Hydrolysis of Pretreated Creeping Wild Ryegrass

    Science.gov (United States)

    Zheng, Yi; Pan, Zhongli; Zhang, Ruihong; Wang, Donghai; Jenkins, Bryan

    Our previous research has shown that saline Creeping Wild Ryegrass (CWR), Leymus triticoides, has a great potential to be used for bioethanol production because of its high fermentable sugar yield, up to 85% cellulose conversion of pretreated CWR. However, the high cost of enzyme is still one of the obstacles making large-scale lignocellulosic bioethanol production economically difficult. It is desirable to use reduced enzyme loading to produce fermentable sugars with high yield and low cost. To reduce the enzyme loading, the effect of addition of non-ionic surfactants and non-catalytic protein on the enzymatic hydrolysis of pretreated CWR was investigated in this study. Tween 20, Tween 80, and bovine serum albumin (BSA) were used as additives to improve the enzymatic hydrolysis of dilute sulfuric-acid-pretreated CWR. Under the loading of 0.1 g additives/g dry solid, Tween 20 was the most effective additive, followed by Tween 80 and BSA. With the addition of Tween 20 mixed with cellulase loading of 15 FPU/g cellulose, the cellulose conversion increased 14% (from 75 to 89%), which was similar to that with cellulase loading of 30 FPU/g cellulose and without additive addition. The results of cellulase and BSA adsorption on the Avicel PH101, pretreated CWR, and lignaceous residue of pretreated CWR support the theory that the primary mechanism behind the additives is prevention of non-productive adsorption of enzymes on lignaceous material of pretreated CWR. The addition of additives could be a promising technology to improve the enzymatic hydrolysis by reducing the enzyme activity loss caused by non-productive adsorption.

  5. Bacterial and fungal communities of wilted Italian ryegrass silage inoculated with and without Lactobacillus rhamnosus or Lactobacillus buchneri.

    Science.gov (United States)

    Li, Y; Nishino, N

    2011-04-01

    To understand the effects of lactic acid bacteria (LAB) inoculation on fermentation products, aerobic stability and microbial communities of silage. Wilted Italian ryegrass was stored in laboratory silos with and without inoculation of Lactobacillus rhamnosus and Lactobacillus buchneri. The silos were opened after 14, 56 and 120 days and then subjected to aerobic deterioration for 7 days. Intensive alcoholic fermentation was found in untreated silage; the sum of ethanol and 2,3-butanediol content at day 14 was about 7 times higher than that of lactic and volatile fatty acids. Alcoholic fermentation was suppressed by L. rhamnosus and L. buchneri inoculation and lactic acid and acetic acid became the dominant fermentation products, respectively. Silages were deteriorated in untreated and L. rhamnosus-inoculated silages, whereas no spoilage was found in L. buchneri-inoculated silage. Enterobacteria such as Erwinia persicina, Pantoea agglomerans and Rahnella aquatilis were detected in untreated silage, whereas some of these bacteria disappeared or became faint with L. rhamnosus treatment. When silage was deteriorated, Lactobacillus brevis and Bacillus pumilus were observed in untreated and L. rhamnosus-inoculated communities, respectively. The inoculated LAB species was detectable in addition to untreated bacterial communities. Saccharomyces cerevisiae and Pichia anomala were the main fungi in untreated and L. rhamnosus-inoculated silages; however, P. anomala was not visibly seen in L. buchneri-inoculated silage either at silo opening or after exposure to air. Inoculation with L. rhamnosus can suppress alcoholic fermentation of wilted grass silage with elimination of enterobacteria at the beginning of fermentation. Addition of L. buchneri may improve aerobic stability, with distinct inhibitory effect observed on P. anomala after silo opening. Bacterial and fungal community analyses help us to understand how inoculated LAB can function to improve the fermentation and

  6. SEASONALITY OF ANNUAL PLANT ESTABLISHMENT INFLUENCES THE INTERACTIONBETWEEN THE NON-NATIVE ANNUAL GRASS BROMUS MADRITENSIS SSP. RUBENS AND MOJAVE DESERT PERENNIALS

    Energy Technology Data Exchange (ETDEWEB)

    L A. DEFALCO; G. C. FERNANDEZ; R. S. NOWAK

    2004-01-01

    Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts

  7. Effect of ryegrass (Lolium perenne L.) roots inoculation using different arbuscular mycorrhizal fungi (AMF) species on sorption of iron-cyanide (Fe-CN) complexes

    Science.gov (United States)

    Sut, Magdalena; Boldt-Burisch, Katja; Raab, Thomas

    2016-04-01

    Soils and groundwater on sites of the former Manufactured Gas Plants (MGPs) are contaminated with various complex iron-cyanides (Fe-CN). Phytoremediation is a promising tool in stabilization and remediation of Fe-CN affected soils, however, it can be a challenging task due to extreme adverse and toxic conditions. Phytoremediation may be enhanced via rhizosphere microbial activity, which can cooperate on the degradation, transformation and uptake of the contaminants. Recently, increasing number of scientist reports improved plants performance in the removal of toxic compounds with the support of arbuscular mycorrhizae fungi (AMF). Series of batch experiments using potassium hexacyanoferrate (II) solutions, in varying concentrations, were used to study the effect of ryegrass roots (Lolium perenne L.) inoculation with Rhizophagus irregularis and a mixture of Rhizophagus irregularis, Funneliformis mosseae, Rhizophagus aggregatus, and Claroideoglomus etunicatum on Fe-CN sorption. Results indicated significantly higher colonization of R. irregularis than for the mixture of AMF species on ryegrass roots. Sorption experiments revealed significantly higher reduction of total CN and free CN content in the mycorrhizal roots, indicating greater cyanide decrease in the treatment inoculated with R. irregularis. Our study indicates contribution of AM fungi in phytoremediation of Fe-CN contaminated soil.

  8. Impact of No-till Cover Cropping of Italian Ryegrass on Above and Below Ground Faunal Communities Inhabiting a Soybean Field with Emphasis on Soybean Cyst Nematodes.

    Science.gov (United States)

    Hooks, Cerruti R R; Wang, Koon-Hui; Meyer, Susan L F; Lekveishvili, Mariam; Hinds, Jermaine; Zobel, Emily; Rosario-Lebron, Armando; Lee-Bullock, Mason

    2011-09-01

    Two field trials were conducted between 2008 and 2010 in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop to reduce populations of plant-parasitic nematodes while enhancing beneficial nematodes, soil mites and arthropods in the foliage of a no-till soybean (Glycine max) planting. Preplant treatments were: 1) previous year soybean stubble (SBS); and 2) herbicide-killed IR cover crop + previous year soybean stubble (referred to as IR). Heterodera glycines population densities were very low and no significant difference in population densities of H. glycines or Pratylenchus spp. were observed between IR and SBS. Planting of IR increased abundance of bacterivorous nematodes in 2009. A reverse trend was observed in 2010 where SBS had higher abundance of bacterivorous nematodes and nematode richness at the end of the cover cropping period. Italian ryegrass also did not affect insect pests on soybean foliage. However, greater populations of spiders were found on soybean foliage in IR treatments during both field trials. Potential causes of these findings are discussed.

  9. Hydrocarbon degradation and plant colonization of selected bacterial strains isolated from the rhizsophere and plant interior of Italian ryegrass and Birdsfoot trefoil

    Science.gov (United States)

    Sohail, Y.; Andria, V.; Reichenauer, T. G.; Sessitsch, A.

    2009-04-01

    Hydrocarbon-degrading strains were isolated from the rhizosphere, root and shoot interior of Italian ryegrass (Lolium multiflorum var. Taurus), Birdsfoot trefoil (Lotus corniculatus var. Leo) grown in a soil contaminated with petroleum oil. Strains were tested regarding their phylogeny and their degradation efficiency. The most efficient strains were tested regarding their suitability to be applied for phytoremediation of diesel oils. Sterilized and non-sterilized agricultural soil, with and with out compost, were spiked with diesel and used for planting Italian ryegrass and birdsfoot trefoil. Four selected strains with high degradation activities, derived from the rhizosphere and plant interior, were selected for individual inoculation. Plants were harvested at flowering stage and plant biomass and hydrocarbon degradation was determined. Furthermore, it was investigated to which extent the inoculant strains were able to survive and colonize plants. Microbial community structures were analysed by 16S rRNA and alkB gene analysis. Results showed efficient colonization by the inoculant strains and improved degradation by the application of compost combined with inoculation as well as on microbial community structures will be presented.

  10. Comparing soil organic carbon dynamics in perennial grasses and shrubs in a saline-alkaline arid region, northwestern China.

    Science.gov (United States)

    Zhou, Yong; Pei, Zhiqin; Su, Jiaqi; Zhang, Jingli; Zheng, Yuanrun; Ni, Jian; Xiao, Chunwang; Wang, Renzhong

    2012-01-01

    Although semi-arid and arid regions account for about 40% of terrestrial surface of the Earth and contain approximately 10% of the global soil organic carbon stock, our understanding of soil organic carbon dynamics in these regions is limited. A field experiment was conducted to compare soil organic carbon dynamics between a perennial grass community dominated by Cleistogenes squarrosa and an adjacent shrub community co-dominated by Reaumuria soongorica and Haloxylon ammodendron, two typical plant life forms in arid ecosystems of saline-alkaline arid regions in northwestern China during the growing season 2010. We found that both fine root biomass and necromass in two life forms varied greatly during the growing season. Annual fine root production in the perennial grasses was 45.6% significantly higher than in the shrubs, and fine root turnover rates were 2.52 and 2.17 yr(-1) for the perennial grasses and the shrubs, respectively. Floor mass was significantly higher in the perennial grasses than in the shrubs due to the decomposition rate of leaf litter in the perennial grasses was 61.8% lower than in the shrubs even though no significance was detected in litterfall production. Soil microbial biomass and activity demonstrated a strong seasonal variation with larger values in May and September and minimum values in the dry month of July. Observed higher soil organic carbon stocks in the perennial grasses (1.32 Kg C m(-2)) than in the shrubs (1.12 Kg C m(-2)) might be attributed to both greater inputs of poor quality litter that is relatively resistant to decay and the lower ability of microorganism to decompose these organic matter. Our results suggest that the perennial grasses might accumulate more soil organic carbon with time than the shrubs because of larger amounts of inputs from litter and slower return of carbon through decomposition.

  11. Selecting native perennial plants for ecological intensification in Mediterranean greenhouse horticulture.

    Science.gov (United States)

    Rodríguez, E; González, M; Paredes, D; Campos, M; Benítez, E

    2017-12-04

    Natural control by predators and parasitoids provides an important and often unnoticed ecosystem service to agricultural landscapes by reducing pest populations in crops. The current model of horticultural intensification in south-eastern Spain produces high yields but has also resulted in a landscape almost completely covered by plastic. Promoting natural areas among greenhouses could enhance biodiversity, by being beneficial insects, and reduce pest pressure outdoors. The first step is to ascertain how pests and their natural enemies (NEs) use Mediterranean vegetation for selecting the best plants for pest suppression outdoors. The abundance of the two major horticultural pests, the tobacco whitefly, Bemisia tabaci, and the western flower thrips, Frankliniella occidentalis, together with their NEs, were assayed in 22 flowering perennial plants, which were newly planted in an experimental field surrounded by greenhouses. Eight plant species were identified as the most critical species for sustaining pest populations outdoors. A set of five plant species supported a medium level of pests, and another set of ten plant species supported the lowest level of both pests. Tobacco whitefly occurred in a few plants species, whereas western flower thrips occurred on almost all the plant species studied, and was favoured by the presence of flowers in perennial plants. The results suggest that plant diversity may provide relatively few acceptable host plants for tobacco whitefly than for western flower thrips. NEs were generally collected in plants that also supported abundance of pests, indicating that host/prey availability, more than food resources from flowers, was a stronger predictor of NE abundance in perennial plants. Field trials using the plants with the lowest host acceptance by pests are needed in order to ascertain whether pest abundance outdoors is reduced.

  12. Horticultural markets promote alien species invasions: an Estonian case study of herbaceous perennials

    Directory of Open Access Journals (Sweden)

    Merle Ööpik

    2013-06-01

    Full Text Available Gardening is a popular pastime, but commercial horticulture is responsible for the introduction of alien species and contributes to invasions in a variety of ways. Although an extensive international literature is available on plant invasions, it is still important at the national level to examine the influence of local factors. Accordingly, 17 nurseries in Estonia that cultivated and sold perennial alien species were selected, and a list of species and prices was compiled. The relationships between species status, and factors such as their abundance in the wild were examined statistically. A qualitative list of the nationally problematic species among herbaceous perennials was also completed. A total of 880 taxa were recorded, of which 10.3% were native and 89.7% alien. In all, 87.3% of the alien species were still confined to cultivated areas. The ecological and socio-economic characteristics of the taxa were described, and lists of the families of casual, naturalised and invasive aliens were provided. Both native and increasing wild alien species have a very similar profile on the market. Alien species that are less expensive, widely available and have more cultivars per species on the market are also more likely to escape. The invasive status and abundance of escaped aliens in an area increases with residence time. In general, socio-economic factors create new and reflect previous propagule pressures from commercial horticulture, which continuously increase the likelihood of alien species surviving and invading new areas. Our findings suggest that these national socio-economic market-related factors explain much of the invasiveness of various perennial ornamental species, and therefore regional and national authorities urgently need to regulate and control the ornamental plant trade to diminish the risk of new invasions.

  13. Immunomodulatory and antioxidant protective effect of Sarcocornia perennis L. (swampfire) in lead intoxicated rat.

    Science.gov (United States)

    Gargouri, Manel; Hamed, Houda; Akrouti, Amel; Christian, Magné; Ksouri, Riadh; El Feki, Abdelfattah

    2017-11-01

    Lead (Pb) is a very toxic metal present in the environment, causing disturbances of several functions. Preventive or curative effects of halophytic plants against these disorders may be a promising and safe therapeutic strategy. Thus, this study was designed to evaluate in vivo immunomodulatory and antioxidant effects of Sarcocornia perennis extract (Sp) against lead toxicity in rats. Groups of six animals each were treated with plant extract (via food), 6 g/L lead acetate (via drinking water) or a combination of both. At the end of the three-week period, rat exposure to lead caused reduction of liver weight but an increase of that of kidney. Moreover, lead intoxication-induced oxidative stress manifested by significant increases of inflammatory cytokines (except IL-10) and lipid peroxidation (TBARS), compared with the control group. Meanwhile, interleukin-10 (IL-10) and glutathione levels (GSH), as well as antioxidant activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), were decreased. Considering liver and renal markers, lead treatment induced a significant increase in the activities of aminotransferases (AST, ALT), and in the levels of urea, creatinine and phosphorous, whereas total plasma protein, albumin and calcium levels were significantly decreased. S. perennis extract alone did not induce any significant changes in hepatic or renal markers, whereas the antioxidant markers were significantly increased. S. perennis supplementation significantly reduced the lead-induced elevation of serum IL-1ß, IL-6, TNF-α, IFN-γ and TBARS but increased the IL-10 and antioxidant enzyme activities. Overall, plant components ameliorated hepatorenal damages caused by lead.

  14. A Decade of Carbon Flux Measurements with Annual and Perennial Crop Rotations on the Canadian Prairies

    Science.gov (United States)

    Amiro, B. D.; Tenuta, M.; Gao, X.; Gervais, M.

    2016-12-01

    The Fluxnet database has over 100 cropland sites, some of which have long-term (over a decade) measurements. Carbon neutrality is one goal of sustainable agriculture, although measurements over many annual cropping systems have indicated that soil carbon is often lost. Croplands are complex systems because the CO2 exchange depends on the type of crop, soil, weather, and management decisions such as planting date, nutrient fertilization and pest management strategy. Crop rotations are often used to decrease pest pressure, and can range from a simple 2-crop system, to have 4 or more crops in series. Carbon dioxide exchange has been measured using the flux-gradient technique since 2006 in agricultural systems in Manitoba, Canada. Two cropping systems are being followed: one that is a rotation of annual crops (corn, faba bean, spring wheat, rapeseed, barley, spring wheat, corn, soybean, spring wheat, soybean); and the other with a perennial phase of alfalfa/grass in years 3 to 6. Net ecosystem production ranged from a gain of 330 g C m-2 y-1 in corn to a loss of 75 g C m-2 y-1 in a poor spring-wheat crop. Over a decade, net ecosystem production for the annual cropping system was not significantly different from zero (carbon neutral), but the addition of the perennial phase increased the sink to 130 g C m-2 y-1. Once harvest removals were included, there was a net loss of carbon ranging from 77 g C m-2 y-1 in the annual system to 52 g C m-2 y-1 in the annual-perennial system; but neither of these were significantly different from zero. Termination of the perennial phase of the rotation only caused short-term increases in respiration. We conclude that both these systems were close to carbon-neutral over a decade even though they were tilled with a short growing season (90 to 130 days). We discuss the need for more datasets on agricultural systems to inform management options to increase the soil carbon sink.

  15. Life cycle analysis of multi-crop lignocellulosic material (perennial grasses) for bioethanol production in western Canada : a review.

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, A. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural and Bioresource Engineering; Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK (Canada). Bioproducts and Bioprocessing; Panigrahi, S. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Agricultural and Bioresource Engineering; Mupondwa, E.K. [Agriculture and Agri-Food Canada, Saskatoon Research Centre, Saskatoon, SK (Canada). Bioproducts and Bioprocessing

    2009-07-01

    This paper presented a life cycle assessment of multi-crop lignocellulosic biomass to determine the environmental performance of a bioethanol biorefinery in western Canada. The study investigated the economic aspects of the ethanol fuel system such as biorefinery operating costs and possible improvements in biorefinery economics resulting from pretreatment, hydrolysis, and fermentation processes. The eco-efficiency was determined by comparing economic parameters with selected environmental parameters. The study also compared the efficiency of the lignoce lulosic biorefinery with grain-based dry milling ethanol plants that produce ethanol as well as dried grains and solubles used as animal feed. The study showed that the choice of feedstock and location of the biorefinery is very important. The location should be carefully chosen where there is no water shortage. Various low valued lignocellulosic energy crops such as switch grass, alfalfa, and other perennial grasses can grow in marginal or pasture land and can decrease production costs considerably, thus improving the economic viability of biorefineries. The use of co-products can also add value to the process and can decrease the cost of ethanol production. tabs., figs.

  16. Effect of seed rate and row spacing in seed production of Festulolium

    OpenAIRE

    Deleuran, L.C.; Gislum, R.; Boelt, B.

    2010-01-01

    Establishment methods have proven to be of major importance for grass seed production. The objective of this research was to test the effect of different sowing techniques on plant establishment and the subsequent seed yield. Perennial ryegrass (Lolium perenne L.) is used as the model grass due to its large importance in Danish agriculture. In a three-year trial six different methods of under-sowing of perennial ryegrass in a spring barley cover crop were employed. Perennial ryegrass was e...

  17. Application of molecular markers for variety protection of ryegrass (Lolium perenne L.)

    DEFF Research Database (Denmark)

    Jensen, Louise Bach; Deneken, Gerhard; Roulund, N

    2008-01-01

    registration systems. Although DUS testing currently employs mostly visually observable characteristics that are expressions of the phenotype of a variety, there is much interest in the use of molecular markers. The overall objective of this project is to examine the potential use of molecular markers...... with 140 alleles gives the same level of information. Furthermore, number of genotypes per variety can be reduced to 20 compared to the original dataset containing 60 genotypes when using all 18 SSR markers but not when using only six SSR markers. Significant association was found between the molecular...... on the morphological characterization from the DUS trial. 18 SSR markers were selected based on their genome distribution, reproducibility, level of information and ease of scoring. It was found, that for variety discrimination, reducing the number of SSR markers from 18 SSR markers with 262 alleles to six SSR markers...

  18. Application of perennial legume green manures to improve growth and yield of organic lowland rice

    Directory of Open Access Journals (Sweden)

    M Winarni

    2016-10-01

    Full Text Available A pot experiment in green house was done to study the effect of the dosage and speciesof perennial legume green manures to the physiological traits, growth and yield of organic lowland rice (Oryza sativaL., and to obtain the optimal dosage as well.  The research was arranged in a factorial randomized block design consistedof two factors with three replications.The first factor was the species of perennial legume thatconsisted of threespecies: Turi (Sesbaniagrandiflora, Glirisidia (Gliricidiasepium, and Lamtoro (Leucaenaleucocephala and cow manure as control treatment. The second factor was the dosage of green manure thatconsisted of four levels: 5, 10, 20 and 40 t/ha.  The results showed that application ofperennial legumesinto the soil significantly improved the growth and yield of rice.  The application of  20 t Glirisidia leaves/haproduced the highest grain yield, followed by 20 t Lamtoro leaves/ha and 20 t Turi leaves/ha.  The optimal dosages of S. grandiflora, G. sepium and L. leucochepala leaves that could yield 58.03 g/hill (equivalent to14.51 t/ha, 53.67 g/hill (equivalent to 13.42 t/ha, and 49.67 g/hill (equivalent to 12.42 t/ha were 28.05, 25.46 and 26.41 t/ha, respectively.

  19. Progress and Bottlenecks in the Early Domestication of the Perennial Oilseed Silphium integrifolium, a Sunflower Substitute

    Directory of Open Access Journals (Sweden)

    Alejandra Vilela

    2018-02-01

    Full Text Available Silflower (Silphium integrifolium Michx. is in the early stages of domestication as a perennial version of oilseed sunflower, its close relative. Grain crops with deep perennial root systems will provide farmers with new alternatives for managing soil moisture and limiting or remediating soil erosion, fertilizer leaching, and loss of soil biota. Several cycles of selection for increased seed production potential following initial germplasm evaluation in 2002 have provided opportunities to document the botany and ecology of this relatively obscure species, to compare agronomic practices for improving its propagation and management, and to evaluate the differences between semi-domesticated and wild accessions that have accrued over this time through intentional and unintentional genetic processes. Key findings include: domestication has increased aboveground biomass at seedling and adult stages; seed yield has increased more, achieving modest improvement in harvest index. Harvest index decreases with nitrogen fertilization. Silflower acquires nitrogen and water from greater depth than typical crops. In agricultural silflower stands within its native range, we found that Puccinia silphii (rust and Eucosma giganteana (moth populations build up to unacceptable levels, but we also found genetic variation for traits contributing to resistance or tolerance. Breeding or management for reduced height and vegetative plasticity should be top priorities for future silflower research outside its native range.

  20. Root Characteristics of Perennial Warm-Season Grasslands Managed for Grazing and Biomass Production

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2013-07-01

    Full Text Available Minirhizotrons were used to study root growth characteristics in recently established fields dominated by perennial C4-grasses that were managed either for cattle grazing or biomass production for bioenergy in Virginia, USA. Measurements over a 13-month period showed that grazing resulted in smaller total root volumes and root diameters. Under biomass management, root volume was 40% higher (49 vs. 35 mm3 and diameters were 20% larger (0.29 vs. 0.24 mm compared to grazing. While total root length did not differ between grazed and biomass treatments, root distribution was shallower under grazed areas, with 50% of total root length in the top 7 cm of soil, compared to 41% in ungrazed exclosures. These changes (i.e., longer roots and greater root volume in the top 10 cm of soil under grazing but the reverse at 17–28 cm soil depths were likely caused by a shift in plant species composition as grazing reduced C4 grass biomass and allowed invasion of annual unsown species. The data suggest that management of perennial C4 grasslands for either grazing or biomass production can affect root growth in different ways and this, in turn, may have implications for the subsequent carbon sequestration potential of these grasslands.

  1. Impact of perennial energy crops income variability on the crop selection of risk averse farmers

    International Nuclear Information System (INIS)

    Alexander, Peter; Moran, Dominic

    2013-01-01

    The UK Government policy is for the area of perennial energy crops in the UK to expand significantly. Farmers need to choose these crops in preference to conventional rotations for this to be achievable. This paper looks at the potential level and variability of perennial energy crop incomes and the relation to incomes from conventional arable crops. Assuming energy crop prices are correlated to oil prices the results suggests that incomes from them are not well correlated to conventional arable crop incomes. A farm scale mathematical programming model is then used to attempt to understand the affect on risk averse farmers crop selection. The inclusion of risk reduces the energy crop price required for the selection of these crops. However yields towards the highest of those predicted in the UK are still required to make them an optimal choice, suggesting only a small area of energy crops within the UK would be expected to be chosen to be grown. This must be regarded as a tentative conclusion, primarily due to high sensitivity found to crop yields, resulting in the proposal for further work to apply the model using spatially disaggregated data. - Highlights: ► Energy crop and conventional crop incomes suggested as uncorrelated. ► Diversification effect of energy crops investigated for a risk averse farmer. ► Energy crops indicated as optimal selection only on highest yielding UK sites. ► Large establishment grant rates to substantially alter crop selections.

  2. Syngas Production from Pyrolysis of Nine Composts Obtained from Nonhybrid and Hybrid Perennial Grasses

    Directory of Open Access Journals (Sweden)

    Adéla Hlavsová

    2014-01-01

    Full Text Available A pyrolysis of compost for the production of syngas with an explicit H2/CO = 2 or H2/CO = 3 was investigated in this study. The composts were obtained from nonhybrid (perennial grasses (NHG and hybrid (perennial grasses (HG. Discrepancies in H2 evolution profiles were found between NHG and HG composts. In addition, positive correlations for NHG composts were obtained between (i H2 yield and lignin content, (ii H2 yield and potassium content, and (iii CO yield and cellulose content. All composts resulted in H2/CO = 2 and five of the nine composts resulted in H2/CO = 3. Exceptionally large higher heating values (HHVs of pyrolysis gas, very close to HHVs of feedstock, were obtained for composts made from mountain brome (MB, 16.23 MJ/kg, hybrid Becva (FB, 16.45 MJ/kg, and tall fescue (TF, 17.43 MJ/kg. The MB and FB composts resulted in the highest syngas formation with H2/CO = 2, whereas TF compost resulted in the highest syngas formation with H2/CO = 3.

  3. IQ Score of Children with Persistent or Perennial Allergic Rhinitis: A Comparison with Healthy Children.

    Science.gov (United States)

    Ghaffari, Javad; Abbaskhanian, Ali; Jalili, Masumeh; Yazdani Charati, Jamshid

    2014-01-01

    Prevalence of allergies is different around the world. Allergic rhinitis is a common chronic disease in children. Intelligence quotient (IQ) is an indicator of efficacy and many factors including chronic diseases may affect it. This study compares the IQs of children diagnosed with persistent or perennial allergic rhinitis with healthy children. This was a comparative study that was conducted from June 2011-May 2013 in an academic referral clinic. In this study, 90 patients aged 6- to 14-yearsold who were diagnosed with persistent or perennial allergic rhinitis and were compared to 90 age and gender match healthy patients from their respective families. The Wechsler Intelligence Scale for Children was used to divide and calculate overall IQ, verbal IQ, and practical IQ. The t-test and chi square were used to analyze quantitative variables and qualitative variables, respectively. In this study, out of total 180 children, 90 (50%) in the case group and 90 children (50%), the control group participated for IQ comparison. One hundred (57%) were male and 80 (43%) were female. The overall IQ for allergic rhinitis patients and healthy patients was 109.2 and 107.5, respectively. This difference was not considered significant. Furthermore, there was no significant difference between the IQ scores of males and females. Although allergic rhinitis is a chronic disease and effects quality of life, there were no identifiable negative effects on IQ.

  4. Does a decade of elevated [CO2] affect a desert perennial plant community?

    Science.gov (United States)

    Newingham, Beth A; Vanier, Cheryl H; Kelly, Lauren J; Charlet, Therese N; Smith, Stanley D

    2014-01-01

    Understanding the effects of elevated [CO2 ] on plant community structure is crucial to predicting ecosystem responses to global change. Early predictions suggested that productivity in deserts would increase via enhanced water-use efficiency under elevated [CO2], but the response of intact arid plant communities to elevated [CO2 ] is largely unknown. We measured changes in perennial plant community characteristics (cover, species richness and diversity) after 10 yr of elevated [CO2] exposure in an intact Mojave Desert community at the Nevada Desert Free-Air CO2 Enrichment (FACE) Facility. Contrary to expectations, total cover, species richness, and diversity were not affected by elevated [CO2]. Over the course of the experiment, elevated [CO2] had no effect on changes in cover of the evergreen C3 shrub, Larrea tridentata; alleviated decreases in cover of the C4 bunchgrass, Pleuraphis rigida; and slightly reduced the cover of C3 drought-deciduous shrubs. Thus, we generally found no effect of elevated [CO2] on plant communities in this arid ecosystem. Extended drought, slow plant growth rates, and highly episodic germination and recruitment of new individuals explain the lack of strong perennial plant community shifts after a decade of elevated [CO2]. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  5. PERENNIAL HELIANTHUS TAXA IN TÂRGU-MURES CITY AND ITS SURROUNDINGS

    Directory of Open Access Journals (Sweden)

    FILEP RITA

    2010-12-01

    Full Text Available Although in the neighbouring countries several perennial Helianthus taxa have been recorded in the last decade, in Romania only three have been identified so far. The literature and herbaria data of Târgu-Mures date back to the end of the XIXth century, and only refer to H. × multiflorus and H. tuberosus. The aim of this study was to identify the perennial Helianthus taxa in this region and to prepare their current distribution map. The survey was conducted in Târgu Mures city and the neighbouring villages: Livezeni, Sântana de Mures, Sâncraiu de Mures, Sângeorgiu de Mures, and Corunca. Four taxa were identified: H. pauciflorus Nutt., H. × laetiflorus Pers., H. tuberosus L. s.str., and Helianthus tuberosus L. s.l. The first two taxa are cultivated as ornamental plants, H. tuberosus s. str. is cultivated in a few farms, whereas H. tuberosus s. l. is an invasive species that spreads along the rivers.

  6. Modeling plant interspecific interactions from experiments with perennial crop mixtures to predict optimal combinations.

    Science.gov (United States)

    Halty, Virginia; Valdés, Matías; Tejera, Mauricio; Picasso, Valentín; Fort, Hugo

    2017-12-01

    The contribution of plant species richness to productivity and ecosystem functioning is a longstanding issue in ecology, with relevant implications for both conservation and agriculture. Both experiments and quantitative modeling are fundamental to the design of sustainable agroecosystems and the optimization of crop production. We modeled communities of perennial crop mixtures by using a generalized Lotka-Volterra model, i.e., a model such that the interspecific interactions are more general than purely competitive. We estimated model parameters -carrying capacities and interaction coefficients- from, respectively, the observed biomass of monocultures and bicultures measured in a large diversity experiment of seven perennial forage species in Iowa, United States. The sign and absolute value of the interaction coefficients showed that the biological interactions between species pairs included amensalism, competition, and parasitism (asymmetric positive-negative interaction), with various degrees of intensity. We tested the model fit by simulating the combinations of more than two species and comparing them with the polycultures experimental data. Overall, theoretical predictions are in good agreement with the experiments. Using this model, we also simulated species combinations that were not sown. From all possible mixtures (sown and not sown) we identified which are the most productive species combinations. Our results demonstrate that a combination of experiments and modeling can contribute to the design of sustainable agricultural systems in general and to the optimization of crop production in particular. © 2017 by the Ecological Society of America.

  7. Drought mitigation in perennial crops by fertilization and adjustments of regional yield models for future climate variability

    Science.gov (United States)

    Kantola, I. B.; Blanc-Betes, E.; Gomez-Casanovas, N.; Masters, M. D.; Bernacchi, C.; DeLucia, E. H.

    2017-12-01

    Increased variability and intensity of precipitation in the Midwest agricultural belt due to climate change is a major concern. The success of perennial bioenergy crops in replacing maize for bioethanol production is dependent on sustained yields that exceed maize, and the marketing of perennial crops often emphasizes the resilience of perennial agriculture to climate stressors. Land conversion from maize for bioethanol to Miscanthus x giganteus (miscanthus) increases yields and annual evapotranspiration rates (ET). However, establishment of miscanthus also increases biome water use efficiency (the ratio between net ecosystem productivity after harvest and ET), due to greater belowground biomass in miscanthus than in maize or soybean. In 2012, a widespread drought reduced the yield of 5-year-old miscanthus plots in central Illinois by 36% compared to the previous two years. Eddy covariance data indicated continued soil water deficit during the hydrologically-normal growing season in 2013 and miscanthus yield failed to rebound as expected, lagging behind pre-drought yields by an average of 53% over the next three years. In early 2014, nitrogen fertilizer was applied to half of mature (7-year-old) miscanthus plots in an effort to improve yields. In plots with annual post-emergence application of 60 kg ha-1 of urea, peak biomass was 29% greater than unfertilized miscanthus in 2014, and 113% greater in 2015, achieving statistically similar yields to the pre-drought average. Regional-scale models of perennial crop productivity use 30-year climate averages that are inadequate for predicting long-term effects of short-term extremes on perennial crops. Modeled predictions of perennial crop productivity incorporating repeated extreme weather events, observed crop response, and the use of management practices to mitigate water deficit demonstrate divergent effects on predicted yields.

  8. Isolation of cDNA encoding a newly identified major allergenic protein of rye-grass pollen: intracellular targeting to the amyloplast.

    Science.gov (United States)

    Singh, M B; Hough, T; Theerakulpisut, P; Avjioglu, A; Davies, S; Smith, P M; Taylor, P; Simpson, R J; Ward, L D; McCluskey, J

    1991-01-01

    We have identified a major allergenic protein from rye-grass pollen, tentatively designated Lol pIb of 31kDa and with pI 9.0. A cDNA clone encoding Lol pIb has been isolated, sequenced, and characterized. Lol pIb is located mainly in the starch granules. This is a distinct allergen from Lol pI, which is located in the cytosol. Lol pIb is synthesized in pollen as a pre-allergen with a transit peptide targeting the allergen to amyloplasts. Epitope mapping of the fusion protein localized the IgE binding determinant in the C-terminal domain. Images PMID:1671715

  9. Linking resilience theory and diffusion of innovations theory to understand the potential for perennials in the U.S. Corn Belt

    Science.gov (United States)

    Ryan C. Atwell; Lisa A. Schulte; Lynne M. Westphal

    2009-01-01

    In the last 200 yr, more than 80% of the land in the U.S. Corn Belt agro-ecosystem has been converted from natural perennial vegetation to intensive agricultural production of row crops. Despite research showing how re-integration of perennial vegetation, e.g., cover crops, pasture, riparian buffers, and restored wetlands, at strategic landscape positions can bolster...

  10. Impacts of managing perennial grasses in the northern Midwest United States for bioenergy on soil organic C and nitrous oxide emission

    Science.gov (United States)

    In the USA perennial grasses [e.g., switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerdardii Vitman)] are proposed as cellulosic feedstock. Perennial grasses are often touted as being low input and as having a C-neutral foot print, but managing them as bioenergy feedstock means addin...

  11. Study on absorption and translocation amounts of 2,4-D on perennial weed( Glycyrrhiza glabra) by 19 C- labelled herbicides tracer technique

    International Nuclear Information System (INIS)

    Ahari Mostafavi, H.; Fatholahi, H.; Naserian, B.

    2004-01-01

    Glycyrrhiza glabra a perennial broad leaf weed, is very difficult to control due to it's powerful root system. The best chemical treatment to perennial weeds control is the application of systemic herbicides and their effect is related to amount of permeability and mobility

  12. EFECTO DEL PICADO SOBRE LAS CARACTERÍSTICAS NUTRICIONALES Y FERMENTATIVAS DE ENSILAJES DE PASTOS KIKUYO, RYEGRASS PERENNE Y ALPISTE FORRAJERO

    Directory of Open Access Journals (Sweden)

    Luis Villalobos

    2016-01-01

    Full Text Available Se evaluó el efecto del picado sobre las características nutricionales y fermentativas de ensilajes elaborados con 3 pastos (kikuyo, rye-grass perenne y alpiste forrajero. Se elaboraron 2 microsilos de cada pasto en bolsas de polieti-leno con capacidad para 1 kg, aplicando 2 trata-mientos (picado y sin picar; se adicionó a cada microsilo 3% de melaza y 0,1% de un inóculo artesanal (hecho de leche agria, suero de queso y melaza. La especie de pasto tuvo el mayor impacto sobre las características nutricionales y fermentativas de los microsilos, mientras que el picado no mostró tendencia clara sobre los parámetros evaluados. El contenido de PC (14,40 a 19,35%, FDN (46,25 a 63,16% y la DIVMS (46,15 a 65,55% en los ensilados es indicador de su potencial para llenar gran parte de los requerimientos nutricionales del ganado lechero. El pasto ryegrass ensilado alcanzó los niveles de pH (4,41 a 4,83 menores y el pasto kikuyo los valores menores de capacidad amor-tiguadora (79,12 a 81,17 mEq NaOH 100 g-1 MS y de nitrógeno amoniacal (1,03 a 1,33%. Los ensilajes elaborados con pastos pueden uti-lizarse como suplementos con valor nutricional superior a los henos utilizados en las raciones de ganado lechero en zonas altas.

  13. Teste de envelhecimento precoce para sementes de azevém, aveia preta e milheto Accelerated aging test for ryegrass black oat grass and pearl millet seeds

    Directory of Open Access Journals (Sweden)

    Danton Camacho Garcia

    1999-06-01

    Full Text Available A viabilidade da aplicação e da padronização do teste de envelhecimento precoce em sementes de azevém, aveia preta e milheto foi verificada em três lotes, para cada espécie, com valores iniciais de germinação semelhantes. As sementes de cada lote foram submetidas ao teste por períodos de 24, 48, 72, 96 e 120 horas, à temperatura de 41°C e 100% de umidade relativa do ar. Em aveia preta, o período de 24 horas estratifica lotes de sementes pelo vigor. Para milheto e azevém, o período de envelhecimento para estratificar lotes de sementes pelo vigor pode ser de 24 a 48 horas. Períodos de 72 a 120 horas são muito drásticos para as três espécies e impedem a estratificação de lotes de sementes pelo vigor.Accelerated aging test standardization for seeds of ryegrass, black oat grass and pearl millet was cheked in three lots, of each specie, with similar initial values of germination. The seeds of each lot were submited to periods of 24, 48, 96 and 120 hours of temperature of 41°C and air relative humidity of 100%. In black oat grass the 24h period stratifies seed vigor among lots. However, for pearl millet and ryegrass the period can be of 24 to 48h. Periods of 72 to 120 hours are very severe to the three species and prevent the seed vigor lots stratification.

  14. Nasal inhalation of budesonide from a spacer in children with perennial rhinitis and asthma

    DEFF Research Database (Denmark)

    Pedersen, W; Hjuler, Inga Merete; Bisgaard, H

    1998-01-01

    and asthma inhaled budesonide through the nose from a pressurized aerosol, attached to a spacer device, in a double-blind, placebo-controlled, crossover study. Compared with placebo, budesonide treatment resulted in a significant reduction of nasal symptoms (Pasthma symptoms (P...The standard treatment of allergic rhinitis and asthma consists of topical corticosteroids administered intranasally and inhaled through the mouth. Although this therapy is highly effective, and side-effects are few and mild, it may be possible further to improve the therapeutic index and patient...... compliance with the treatment. In the present study, we evaluated a nasal inhalation system used for the simultaneous treatment of rhinitis and asthma. In principle, it results in an airway deposition of the corticosteroid similar to that of inhaled allergens. Twenty-four children with perennial rhinitis...

  15. Phytochemical Profile and Qualification of Biological Activity of an Isolated Fraction of Bellis perennis

    Directory of Open Access Journals (Sweden)

    Thiago H Costa Marques

    2013-01-01

    Full Text Available This study describes the isolation and identification of apigenin-7-O-ghicopyranoside, a flavonoid isolated from the flowers of Bellis perennis L., Asteraceae, an species with a broad spectrum of biological activities. The in vitro antioxidant activity and the inhibition of the enzyme acetylcholinesterase were evaluated. The flavonoid showed strong in vitro antioxidant potential, because of the capacity of removal of hydroxyl radicals and nitric oxide, and also prevented the formation of thiobarbituric acid-reactive substances. These parameters were inhibited at the highest concentration of ApG at rates of 77.7%, 72% and 73.4%, respectively, in addition to inhibiting acetylcholinesterase, suggesting potential use in the treatment of neurodegenerative diseases.

  16. Root growth of perennials in vertical growing media for use in green walls

    DEFF Research Database (Denmark)

    Jørgensen, Lars; Dresbøll, Dorte Bodin; Thorup-Kristensen, Kristian

    2014-01-01

    The vertical orientation of green walls causes a risk of uneven water distribution within the growing medium, and thereby stress on the plant roots. Therefore it was studied how the root and top growth of different species were affected by the water holding characteristics of the growing media....... Five species of hardy perennials (Campanula poscharskyana ‘Stella’, Fragaria vesca ‘Småland’, Geranium sanguineum ‘Max Frei’, Sesleria heufleriana and Veronica officinalis ‘Allgrün’) were grown in 3 types of growing media (coir and 2 of rockwool) in vertical boxes under greenhouse conditions. Root...... distribution was registered over 52 days and the activity of individual root systems was studied via 15N uptake and plant parameters were measured. The water holding characteristics of the growing media was determined on a sandbox. From day 21 and throughout the experiment, the plants growing in the coir...

  17. High quality reference genome of drumstick tree (Moringa oleifera Lam.), a potential perennial crop.

    Science.gov (United States)

    Tian, Yang; Zeng, Yan; Zhang, Jing; Yang, ChengGuang; Yan, Liang; Wang, XuanJun; Shi, ChongYing; Xie, Jing; Dai, TianYi; Peng, Lei; Zeng Huan, Yu; Xu, AnNi; Huang, YeWei; Zhang, JiaJin; Ma, Xiao; Dong, Yang; Hao, ShuMei; Sheng, Jun

    2015-07-01

    The drumstick tree (Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera. This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera's high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera, and may further promote applying genomics to enhanced breeding and improvement of M. oleifera.

  18. White grubs (Cyclocephala flavipennis damaging perennial winter pastures in the South Region of Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Gonçalves Duchini

    Full Text Available ABSTRACT: Cyclocephala flavipennis Arrow, 1914 (Coleoptera: Melolonthidae, popularly known as white grub, is an insect widely disseminated in the South Region of Brazil. Despite the frequent occurrence of this white grub in areas cultivated with winter cereals, it is generally not considered a pest, since it feeds on straw and dead plant material. However, in 2015 and 2016, this insect has been identified as the damage-causing agent in the perennial winter pastures in Lages, Santa Catarina, Brazil. Damage was observed in patches and caused reduction in root depth and mass, resulting in loss of vigor, accelerated senescence in aerial parts, and death of tillers in Festuca arundinacea Schreb. and Dactylis glomerata L. plants.

  19. Distribution of photosynthetically fixed 14C in perennial plant species of the northern Mojave Desert

    International Nuclear Information System (INIS)

    Wallace, A.; Cha, J.W.; Romney, E.M.

    1980-01-01

    The distribution of photosynthate among plant parts subsequent to its production is needed to fully understand behavior of vegetation in any ecosystem. The present study, undertaken primarily to obtain information on transport of assimilates into roots of desert vegetation, was conducted in the northern Mojave Desert, where the mean annual rainfall is about 10 cm. Shoots of Ambrosia dumosa (A. Gray) Payne plants were exposed to 14 CO 2 in 1971, and the distribution of 14 C in roots, stems, and leaves was subsequently measured at 1 week, 2 months, and 5 months. Only about 12 percent of the 14 C photosynthate was stored in the root. Much of that stored in stems was available for new leaf growth. Photosynthate was labeled with 14 C for 24 plants representing eight species in 1972. Results showed that after 127 days the mean percentage of 14 C in roots as compared with the estimate of that originally fixed was 11.8; the percentage in stems was 43.8. To check the validity of the 14 C data, root growth of eight perennial desert plants grown in the glasshouse was followed as plants increased in size. The mean percent of the whole plant that was root for eight species was 17.7 percent. The mean proportion of the increase in plant weights that went below ground for the eight species was 19.5 percent. This value is higher than the fraction of 14 C found below ground, and therefore the 14 C technique underestimates the movement of C to roots. Results of an experiment designed to test the value of the 14 C-pulse technique for determining current root growth for some perennial species from the desert indicated that the transition part of roots where root growth continued after exposure to 14 C was highly labeled. Old growth contained less 14 C than new growth

  20. Holocene climate variability and anthropogenic impacts from Lago Paixban, a perennial wetland in Peten, Guatemala

    Science.gov (United States)

    Wahl, David B.; Hansen, Richard D.; Byrne, Roger; Anderson, Lysanna; Schreiner, T.

    2016-01-01

    Analyses of an ~ 6 m sediment core from Lago Paixban in Peten, Guatemala, document the complex evolution of a perennial wetland over the last 10,300 years. The basal sediment is comprised of alluvial/colluvial fill deposited in the early Holocene. The absence of pollen and gastropods in the basal sediments suggests intermittently dry conditions until ~ 9000 cal yr. BP (henceforth BP) when the basin began to hold water perennially. Lowland tropical forest taxa dominated the local vegetation at this time. A distinct band of carbonate dating to ~ 8200 BP suggests regionally dry conditions, possibly associated with the 8.2 ka event. Wetter conditions during the Holocene Thermal Maximum are indicated by evidence of a raised water level and an open water lake. The timing of this interval coincides with strengthening of the Central American Monsoon. An abrupt change at 5500 BP involved the development of a sawgrass marsh and onset of peat deposition. The lowest recorded water levels date to 5500–4500 BP. Pollen, isotope, geochemical, and sedimentological data indicate that the coring site was near the edge of the marsh during this period. A rise in the water table after 4500 BP persisted until around 3500 BP. Clay marl deposition from 3500 to 210 BP corresponds to the period of Maya settlement. An increase in δ13C, the presence of Zea pollen, and a reduction in the percentage of forest taxa pollen indicate agricultural activity at this time. In contrast to several nearby paleoenvironmental studies, proxy evidence from Lago Paixban indicates human presence through the Classic/Postclassic period transition (~ 1000 BP) and persisting until the arrival of Europeans. Cessation of human activity around 210 BP resulted in local afforestation and the re-establishment of the current sawgrass marsh at Lago Paixban.

  1. Characterization of gene expression associated with drought avoidance and tolerance traits in a perennial grass species.

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    Full Text Available To understand molecular mechanisms of perennial grass adaptation to drought stress, genes associated with drought avoidance or tolerance traits were identified and their expression patterns were characterized in C4 hybrid bermudagrass [Cynodon dactylon (L. Pers.×C. transvaalensis Burtt Davy, cv. Tifway] and common bermudagrass (C. dactylon, cv. C299. Plants of drought-tolerant 'Tifway' and drought-sensitive 'C299' were exposed to drought for 5 d (mild stress and 10 d (severe stress by withholding irrigation in a growth chamber. 'Tifway' maintained significantly lower electrolyte leakage and higher relative water content than 'C299' at both 5 and 10 d of drought stress. Four cDNA libraries via suppression subtractive hybridization analysis were constructed and identified 277 drought-responsive genes in the two genotypes at 5 and 10 d of drought stress, which were mainly classified into the functional categories of stress defense, metabolism, osmoregulation, membrane system, signal and regulator, structural protein, protein synthesis and degradation, and energy metabolism. Quantitative-PCR analysis confirmed the expression of 36 drought up-regulated genes that were more highly expressed in drought-tolerant 'Tifway' than drought-sensitive 'C299', including those for drought avoidance traits, such as cuticle wax formation (CER1 and sterol desaturase, for drought tolerance traits, such as dehydration-protective proteins (dehydrins, HVA-22-like protein and oxidative stress defense (superoxide dismutase, dehydroascorbate reductase, 2-Cys peroxiredoxins, and for stress signaling (EREBP-4 like protein and WRKY transcription factor. The results suggest that the expression of genes for stress signaling, cuticle wax accumulation, antioxidant defense, and dehydration-protective protein accumulation could be critically important for warm-season perennial grass adaptation to long-term drought stress.

  2. Holocene climate variability and anthropogenic impacts from Lago Paixban, a perennial wetland in Peten, Guatemala

    Science.gov (United States)

    Wahl, David; Hansen, Richard D.; Byrne, Roger; Anderson, Lysanna; Schreiner, Thomas

    2016-03-01

    Analyses of an 6 m sediment core from Lago Paixban in Peten, Guatemala, document the complex evolution of a perennial wetland over the last 10,300 years. The basal sediment is comprised of alluvial/colluvial fill deposited in the early Holocene. The absence of pollen and gastropods in the basal sediments suggests intermittently dry conditions until 9000 cal yr. BP (henceforth BP) when the basin began to hold water perennially. Lowland tropical forest taxa dominated the local vegetation at this time. A distinct band of carbonate dating to 8200 BP suggests regionally dry conditions, possibly associated with the 8.2 ka event. Wetter conditions during the Holocene Thermal Maximum are indicated by evidence of a raised water level and an open water lake. The timing of this interval coincides with strengthening of the Central American Monsoon. An abrupt change at 5500 BP involved the development of a sawgrass marsh and onset of peat deposition. The lowest recorded water levels date to 5500-4500 BP. Pollen, isotope, geochemical, and sedimentological data indicate that the coring site was near the edge of the marsh during this period. A rise in the water table after 4500 BP persisted until around 3500 BP. Clay marl deposition from 3500 to 210 BP corresponds to the period of Maya settlement. An increase in δ13C, the presence of Zea pollen, and a reduction in the percentage of forest taxa pollen indicate agricultural activity at this time. In contrast to several nearby paleoenvironmental studies, proxy evidence from Lago Paixban indicates human presence through the Classic/Postclassic period transition ( 1000 BP) and persisting until the arrival of Europeans. Cessation of human activity around 210 BP resulted in local afforestation and the re-establishment of the current sawgrass marsh at Lago Paixban.

  3. Water deficit mechanisms in perennial shrubs Cerasus humilis leaves revealed by physiological and proteomic analyses.

    Science.gov (United States)

    Yin, Zepeng; Ren, Jing; Zhou, Lijuan; Sun, Lina; Wang, Jiewan; Liu, Yulong; Song, Xingshun

    2016-01-01

    Drought (Water deficit, WD) poses a serious threat to extensively economic losses of trees throughout the world. Chinese dwarf cherry ( Cerasus humilis ) is a good perennial plant for studying the physiological and sophisticated molecular network under WD. The aim of this study is to identify the effect of WD on C. humilis through physiological and global proteomics analysis and improve understanding of the WD resistance of plants. Currently, physiological parameters were applied to investigate C. humilis response to WD. Moreover, we used two-dimensional gel electrophoresis (2DE) to identify differentially expressed proteins in C. humilis leaves subjected to WD (24 d). Furthermore, we also examined the correlation between protein and transcript levels. Several physiological parameters, including relative water content and Pn were reduced by WD. In addition, the malondialdehyde (MDA), relative electrolyte leakage (REL), total soluble sugar, and proline were increased in WD-treated C. humilis . Comparative proteomic analysis revealed 46 protein spots (representing 43 unique proteins) differentially expressed in C. humilis leaves under WD. These proteins were mainly involved in photosynthesis, ROS scavenging, carbohydrate metabolism, transcription, protein synthesis, protein processing, and nitrogen and amino acid metabolisms, respectively. WD promoted the CO 2 assimilation by increase light reaction and Calvin cycle, leading to the reprogramming of carbon metabolism. Moreover, the accumulation of osmolytes (i.e., proline and total soluble sugar) and enhancement of ascorbate-glutathione cycle and glutathione peroxidase/glutathione s-transferase pathway in leaves could minimize oxidative damage of membrane and other molecules under WD. Importantly, the regulation role of carbohydrate metabolisms (e. g. glycolysis, pentose phosphate pathways, and TCA) was enhanced. These findings provide key candidate proteins for genetic improvement of perennial plants metabolism under

  4. Carbon Sequestration by Perennial Energy Crops: Is the Jury Still Out?

    Science.gov (United States)

    Agostini, Francesco; Gregory, Andrew S; Richter, Goetz M

    Soil organic carbon (SOC) changes associated with land conversion to energy crops are central to the debate on bioenergy and their potential carbon neutrality. Here, the experimental evidence on SOC under perennial energy crops (PECs) is synthesised to parameterise a whole systems model and to identify uncertainties and knowledge gaps determining PECs being a sink or source of greenhouse gas (GHG). For Miscanthus and willow ( Salix spp.) and their analogues (switchgrass, poplar), we examine carbon (C) allocation to above- and belowground residue inputs, turnover rates and retention in the soil. A meta-analysis showed that studies on dry matter partitioning and C inputs to soils are plentiful, whilst data on turnover are rare and rely on few isotopic C tracer studies. Comprehensive studies on SOC dynamics and GHG emissions under PECs are limited and subsoil processes and C losses through leaching remain unknown. Data showed dynamic changes of gross C inputs and SOC stocks depending on stand age. C inputs and turnover can now be specifically parameterised in whole PEC system models, whilst dependencies on soil texture, moisture and temperature remain empirical. In conclusion, the annual net SOC storage change exceeds the minimum mitigation requirement (0.25 Mg C ha -1 year -1 ) under herbaceous and woody perennials by far (1.14 to 1.88 and 0.63 to 0.72 Mg C ha -1 year -1 , respectively). However, long-term time series of field data are needed to verify sustainable SOC enrichment, as the physical and chemical stabilities of SOC pools remain uncertain, although they are essential in defining the sustainability of C sequestration (half-life >25 years).

  5. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion

    Science.gov (United States)

    Xiaobo Zhou; Matthew J. Helmers; Heidi Asbjornsen; Randy Kolka; Mark D. Tomer

    2010-01-01

    Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to...

  6. Effects of native perennial vegetation buffer strips on dissolved organic carbon in surface runoff from an agricultural landscape

    Science.gov (United States)

    Tomorra E. Smith; Randall K. Kolka; Xiaobo Zhou; Matthew J. Helmers; Richard M. Cruse; Mark D. Tomer

    2014-01-01

    Dissolved organic carbon (DOC) constitutes a small yet important part of a watershed's carbon budget because it is mobile and biologically active. Agricultural conservation practices such as native perennial vegetation (NPV) strips will influence carbon cycling of an upland agroecosystem, and could affect how much DOC enters streams in runoff, potentially...

  7. Landscape control of nitrous oxide emissions during the transition from conservation reserve program to perennial grasses for bioenergy

    Science.gov (United States)

    Debasish Saha; Benjamin M. Rau; Jason P. Kaye; Felipe Montes; Paul R. Adler; Armen R. Kemanian

    2016-01-01

    Future liquid fuel demand from renewable sources may, in part, be met by converting the seasonally wet portions of the landscape currently managed for soil and water conservation to perennial energy crops. However, this shift may increase nitrous oxide (N2O) emissions, thus limiting the carbon (C) benefits of energy crops. Particularly high emissions may occur during...

  8. Established native perennial grasses out-compete an invasive annual grass regardless of soil water and nutrient availability

    Science.gov (United States)

    Christopher M. McGlone; Carolyn Hull Sieg; Thomas E. Kolb; Ty Nietupsky

    2012-01-01

    Competition and resource availability influence invasions into native perennial grasslands by nonnative annual grasses such as Bromus tectorum. In two greenhouse experiments we examined the influence of competition, water availability, and elevated nitrogen (N) and phosphorus (P) availability on growth and reproduction of the invasive annual grass B. tectorum and two...

  9. Whole-stream metabolism of a perennial spring-fed aufeis field in Alaska, with coincident surface and subsurface flow

    Science.gov (United States)

    Hendrickson, P. J.; Gooseff, M. N.; Huryn, A. D.

    2017-12-01

    Aufeis (icings or naleds) are seasonal arctic and sub-arctic features that accumulate through repeated overflow and freeze events of river or spring discharge. Aufeis fields, defined as the substrate on which aufeis form and the overlaying ice, have been studied to mitigate impacts on engineering structures; however, ecological characteristics and functions of aufeis fields are poorly understood. The perennial springs that supply warm water to aufeis fields create unique fluvial habitats, and are thought to act as winter and summer oases for biota. To investigate ecosystem function, we measured whole-stream metabolism at the Kuparuk River Aufeis (North Slope, AK), a large ( 5 km2) field composed of cobble substrate and predominately subsurface flow dynamics. The single-station open channel diel oxygen method was utilized at several dissolved oxygen (DO) stations located within and downstream of the aufeis field. DO loggers were installed in August 2016, and data downloaded summer 2017. Daily ecosystem respiration (ER), gross primary production (GPP) and reaeration rates were modeled using BASE, a package freely available in the open-source software R. Preliminary results support net heterotrophy during a two-week period of DO measurements in the fall season when minimum ice extent is observed. GPP, ER, and net metabolism are greater at the upstream reach near the spring source (P/R = 0.53), and decrease as flow moves downstream. As flow exits the aufeis field, surface and subsurface flow are incorporated into the metabolism model, and indicate the stream system becomes dependent on autochthonous production (P/R = 0.91). Current work is directed towards spring and summer discharge and metabolic parameter estimation, which is associated with maximum ice extent and rapid melting of the aufeis feature.

  10. Establishing perennial seed-based energy crops on reclaimed surface mine soils in the central Appalachians

    Science.gov (United States)

    Jamie L. Schuler; Shawn Grushecky; Jingxin. Wang

    2014-01-01

    Renewable energy has been at the forefront of the United States' energy policies. Cellulosic feedstocks have received considerable interest in the Appalachian region because of their abundance and availability, but cost competition from other energy sectors has limited their use in the region. Some other bioenergy feedstocks, such as corn and soybeans, are not a...

  11. African Journal of Range and Forage Science - Vol 11, No 1 (1976)

    African Journals Online (AJOL)

    African Journal of Range and Forage Science. ... Changes of biomass in some perennial grass species. ... The use of shoot dimensions to estimate the leaf mass or shoot area of certain indigenous ... Italian ryegrass as a perennial fodder crop.

  12. Phenotypic Plasticity in Reproductive Traits of the Perennial Shrub Ulex europaeus in Response to Shading: A Multi-Year Monitoring of Cultivated Clones.

    Directory of Open Access Journals (Sweden)

    Anne Atlan

    Full Text Available Phenotypic plasticity may be advantageous for plants to be able to rapidly cope with new and changing environments associated with climate change or during biological invasions. This is especially true for perennial plants, as they may need a longer period to respond genetically to selective pressures than annuals, and also because they are more likely to experience environmental changes during their lifespan. However, few studies have explored the plasticity of the reproductive life history traits of woody perennial species. This study focuses on a woody shrub, Ulex europaeus (common gorse, and on the response of its reproductive traits to one important environmental factor, shading. The study was performed on clones originating from western France (within the native range of this invasive species and grown for seven years. We compared traits of plants grown in a shade treatment (with two successive shade levels vs. full natural light. The traits monitored included flowering onset, pod production and seed predation. All traits studied responded to shading, exhibiting various levels of plasticity. In particular, dense shade induced a radical but reversible decrease in flower and pod production, while moderate shade had little effect on reproductive traits. The magnitude of the response to dense shade depended on the genotype, showing a genetically based polymorphism of plasticity. The level of plasticity also showed substantial variations between years, and the effect of environmental variations was cumulative over time. This suggests that plasticity can influence the lifetime fitness of U. Europaeus and is involved in the capacity of the species to grow under contrasting environmental conditions.

  13. Phenotypic Plasticity in Reproductive Traits of the Perennial Shrub Ulex europaeus in Response to Shading: A Multi-Year Monitoring of Cultivated Clones.

    Science.gov (United States)

    Atlan, Anne; Hornoy, Benjamin; Delerue, Florian; Gonzalez, Maya; Pierre, Jean-Sébastien; Tarayre, Michèle

    2015-01-01

    Phenotypic plasticity may be advantageous for plants to be able to rapidly cope with new and changing environments associated with climate change or during biological invasions. This is especially true for perennial plants, as they may need a longer period to respond genetically to selective pressures than annuals, and also because they are more likely to experience environmental changes during their lifespan. However, few studies have explored the plasticity of the reproductive life history traits of woody perennial species. This study focuses on a woody shrub, Ulex europaeus (common gorse), and on the response of its reproductive traits to one important environmental factor, shading. The study was performed on clones originating from western France (within the native range of this invasive species) and grown for seven years. We compared traits of plants grown in a shade treatment (with two successive shade levels) vs. full natural light. The traits monitored included flowering onset, pod production and seed predation. All traits studied responded to shading, exhibiting various levels of plasticity. In particular, dense shade induced a radical but reversible decrease in flower and pod production, while moderate shade had little effect on reproductive traits. The magnitude of the response to dense shade depended on the genotype, showing a genetically based polymorphism of plasticity. The level of plasticity also showed substantial variations between years, and the effect of environmental variations was cumulative over time. This suggests that plasticity can influence the lifetime fitness of U. Europaeus and is involved in the capacity of the species to grow under contrasting environmental conditions.

  14. Morphological characterization and gene expression profiling during bud development in a tropical perennial, Litchi chinensis Sonn.

    Directory of Open Access Journals (Sweden)

    Huifeng Zhang

    2016-10-01

    Full Text Available Tropical evergreen perennials undergo recurrent flush growth, and their terminal buds alternate between growth and dormancy. In sharp contrast to intensive studies on bud development in temperate deciduous trees, there is little information about bud development regulation in tropical trees. In this study, litchi (Litchi chinensis Sonn. was used as a model tropical perennial for morphological characterization and transcriptomic analysis of bud development. Litchi buds are naked with apical meristem embraced by rudimentary leaves, which are brown at dormant stage (Stage I. They swell and turn greenish as buds break (Stage II, and as growth accelerates, the rudimentary leaves elongate and open exposing the inner leaf primodia. With the outgrowth of the needle-like leaflets, bud growth reaches a maximum (Stage III. When leaflets expand, bud growth cease with the abortion of the rudimentary leaves at upper positions (Stage IV. Then buds turn brown and reenter dormant status. Budbreak occurs again when new leaves become hard green. Buds at four stages (Stage I to IV were collected for respiration measurements and in-depth RNA sequencing. Respiration rate was lowest at Stage I and highest at Stage II, decreasing towards growth cessation. RNA sequencing obtained over 5 Gb data from each of the bud samples and de novo assembly generated a total of 59999 unigenes, 40119 of which were annotated. Pair-wise comparison of gene expression between stages, gene profiling across stages, GO/KEGG enrichment analysis, and the expression patterns of 17 major genes highlighted by principal component (PC analysis displayed significant changes in stress resistance, hormone signal pathways, circadian rhythm, photosynthesis, cell division, carbohydrate metabolism, programmed cell death during bud development, which might be under epigenetic control involving chromatin methylation. The qPCR results of 8 selected unigenes with high PC scores agreed with the RPKM values

  15. Homeopathy for Perennial Asthma in Adolescents: Pilot Feasibility Study Testing a Randomised Withdrawal Design.

    Science.gov (United States)

    Mitchiguian Hotta, Livia; Cardinalli Adler, Ubiratan; de Toledo Cesar, Amarilys; Martinez, Edson Zangiacomi; Demarzo, Marcelo Marcos Piva

    2018-05-01

     Previous findings from a pragmatic trial suggest that usual care compared with usual care plus individualised homeopathy is not a feasible design to address homeopathic interventions for asthma.  The main purpose of this article was to investigate the feasibility of the randomised withdrawal design as a strategy to assess the effectiveness of a standardised clinical-pharmaceutical homeopathic protocol ( Organon.modus ) on perennial asthma in adolescents.  Randomised withdrawal, double-blind, parallel, placebo-controlled, 12-week study. 12 to 17 years old adolescents, with the diagnosis of perennial asthma, using inhalatory beclomethasone (plus fenoterol for wheezing episodes), who achieved 3 months of well-controlled asthma, after a variable period of individualised homeopathic treatment according to Organon.modus protocol. a secondary care medical specialist centre. continuation with the individualised homeopathic medicine or with indistinguishable placebo during 12 weeks of beclomethasone step-down. number of days of well-controlled asthma. Secondary measures: number of days of fenoterol use, number of visits to an emergency service (without hospitalisation) and percentage of patients excluded due to an exacerbation characterising a partly controlled asthma. Tolerability was assessed by Adverse Events, registered at every visit.  Nineteen patients were randomised to continue treatment with homeopathy and 21 with placebo. Effectiveness measures for the homeopathy and placebo groups respectively were median number of days of good clinical control: 84 versus 30 ( p  = 0.18); median number of days of fenoterol use per patient: 3 versus 5 ( p  = 0.41); visits to an emergency room: 1 versus 6 ( p  = 0.35); percentage of exclusion due to partly controlled asthma: 36.8% versus 71.4% ( p  = 0.05). Few Adverse Events were reported.  This pilot study supports the feasibility of the double-blind randomised withdrawal design in studies investigating

  16. Water Use and Water-Use Efficiency of Three Perennial Bioenergy Grass Crops in Florida

    Directory of Open Access Journals (Sweden)

    Jerry M. Bennett

    2012-10-01

    Full Text Available Over two-thirds of human water withdrawals are estimated to be used for agricultural production, which is expected to increase as demand for renewable liquid fuels from agricultural crops intensifies. Despite the potential implications of bioenergy crop production on water resources, few data are available on water use of perennial bioenergy grass crops. Therefore, the objective of this study was to compare dry matter yield, water use, and water-use efficiency (WUE of elephantgrass, energycane, and giant reed, grown under field conditions for two growing seasons in North Central Florida. Using scaled sap flow sensor data, water use ranged from about 850 to 1150 mm during the growing season, and was generally greater for giant reed and less for elephantgrass. Despite similar or greater water use by giant reed, dry biomass yields of 35 to 40 Mg ha−1 were significantly greater for energycane and elephantgrass, resulting in greater WUE. Overall, water use by the bioenergy crops was greater than the rainfall received during the study, indicating that irrigation will be needed in the region to achieve optimal yields. Species differ in water use and WUE and species selection can play an important role with regard to potential consequences for water resources.

  17. Epigenetic differentiation persists after male gametogenesis in natural populations of the perennial herb Helleborus foetidus (Ranunculaceae).

    Science.gov (United States)

    Herrera, Carlos M; Medrano, Mónica; Bazaga, Pilar

    2013-01-01

    Despite the importance of assessing the stability of epigenetic variation in non-model organisms living in real-world scenarios, no studies have been conducted on the transgenerational persistence of epigenetic structure in wild plant populations. This gap in knowledge is hindering progress in the interpretation of natural epigenetic variation. By applying the methylation-sensitive amplified fragment length polymorphism (MSAP) technique to paired plant-pollen (i.e., sporophyte-male gametophyte) DNA samples, and then comparing methylation patterns and epigenetic population differentiation in sporophytes and their descendant gametophytes, we investigated transgenerational constancy of epigenetic structure in three populations of the perennial herb Helleborus foetidus (Ranunculaceae). Single-locus and multilocus analyses revealed extensive epigenetic differentiation between sporophyte populations. Locus-by-locus comparisons of methylation status in individual sporophytes and descendant gametophytes showed that ~75% of epigenetic markers persisted unchanged through gametogenesis. In spite of some epigenetic reorganization taking place during gametogenesis, multilocus epigenetic differentiation between sporophyte populations was preserved in the subsequent gametophyte stage. In addition to illustrating the efficacy of applying the MSAP technique to paired plant-pollen DNA samples to investigate epigenetic gametic inheritance in wild plants, this paper suggests that epigenetic differentiation between adult plant populations of H. foetidus is likely to persist across generations.

  18. Epigenetic differentiation persists after male gametogenesis in natural populations of the perennial herb Helleborus foetidus (Ranunculaceae.

    Directory of Open Access Journals (Sweden)

    Carlos M Herrera

    Full Text Available Despite the importance of assessing the stability of epigenetic variation in non-model organisms living in real-world scenarios, no studies have been conducted on the transgenerational persistence of epigenetic structure in wild plant populations. This gap in knowledge is hindering progress in the interpretation of natural epigenetic variation. By applying the methylation-sensitive amplified fragment length polymorphism (MSAP technique to paired plant-pollen (i.e., sporophyte-male gametophyte DNA samples, and then comparing methylation patterns and epigenetic population differentiation in sporophytes and their descendant gametophytes, we investigated transgenerational constancy of epigenetic structure in three populations of the perennial herb Helleborus foetidus (Ranunculaceae. Single-locus and multilocus analyses revealed extensive epigenetic differentiation between sporophyte populations. Locus-by-locus comparisons of methylation status in individual sporophytes and descendant gametophytes showed that ~75% of epigenetic markers persisted unchanged through gametogenesis. In spite of some epigenetic reorganization taking place during gametogenesis, multilocus epigenetic differentiation between sporophyte populations was preserved in the subsequent gametophyte stage. In addition to illustrating the efficacy of applying the MSAP technique to paired plant-pollen DNA samples to investigate epigenetic gametic inheritance in wild plants, this paper suggests that epigenetic differentiation between adult plant populations of H. foetidus is likely to persist across generations.

  19. Perennial pastures for marginal farming country in southern Queensland. 2. Potential new grass cultivar evaluation

    Directory of Open Access Journals (Sweden)

    Richard G. Silcock

    2015-01-01

    Full Text Available Trials in the Condamine-Balonne basin, Australia, compared 11 promising perennial pasture grass accessions (4 Bothriochloa, 2 Cenchrus, 2 Urochloa and 1 each of Digitaria, Eragrostis and Panicum species against the best similar commercial cultivars on the basis of ease of establishment from seed, persistence once established, forage yield and ease of seed production.  Accessions sown at a site were determined by prior experience with them on a range of soils.  High quality seed was relatively easy to produce for both Urochloa species and for Eragrostis curvula CPI 30374 but problematic for the Bothriochloa spp.  Once established, all accessions persisted for 3–5 years and most were well grazed, but adequate establishment was sometimes a problem with Panicum stapfianum and Bothriochloa ewartiana.  The dry matter yield ratings of the non-commercial lines were similar to those of the commercial equivalents of the same species.  While agronomically valuable, none of the promising new grasses was considered worthy of commercialization at this point because their strengths did not warrant the setting up of a seed-production business in competition with current commercial enterprises.  Long-standing cultivars such as Gayndah buffel and Nixon sabi grass continued to exhibit their superior pasture qualities.Keywords: Herbicide tolerance, persistence, forage yield, establishment ease, commercialization, seed production.DOI: 10.17138/TGFT(315-26

  20. Gibberellin Promotes Shoot Branching in the Perennial Woody Plant Jatropha curcas.

    Science.gov (United States)

    Ni, Jun; Gao, Congcong; Chen, Mao-Sheng; Pan, Bang-Zhen; Ye, Kaiqin; Xu, Zeng-Fu

    2015-08-01

    Strigolactone (SL), auxin and cytokinin (CK) interact to regulate shoot branching. CK has long been considered to be the only key phytohormone to promote lateral bud outgrowth. Here we report that gibberellin also acts as a positive regulator in the control of shoot branching in the woody plant Jatropha curcas. We show that gibberellin and CK synergistically promote lateral bud outgrowth, and that both hormones influence the expression of putative branching regulators, J. curcas BRANCHED1 and BRANCHED2, which are key transcription factors maintaining bud dormancy. Moreover, treatment with paclobutrazol, an inhibitor of de novo gibberellin biosynthesis, significantly reduced the promotion of bud outgrowth by CK, suggesting that gibberellin is required for CK-mediated axillary bud outgrowth. In addition, SL, a plant hormone involved in the repression of shoot branching, acted antagonistically to both gibberellin and CK in the control of lateral bud outgrowth. Consistent with this, the expression of JcMAX2, a J. curcas homolog of Arabidopsis MORE AXILLARY GROWTH 2 encoding an F-box protein in the SL signaling pathway, was repressed by gibberellin and CK treatment. We also provide physiological evidence that gibberellin also induces shoot branching in many other trees, such as papaya, indicating that a more complicated regulatory network occurs in the control of shoot branching in some perennial woody plants. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  1. Manipulation of Auxin Response Factor 19 affects seed size in the woody perennial Jatropha curcas

    Science.gov (United States)

    Sun, Yanwei; Wang, Chunming; Wang, Ning; Jiang, Xiyuan; Mao, Huizhu; Zhu, Changxiang; Wen, Fujiang; Wang, Xianghua; Lu, Zhijun; Yue, Genhua; Xu, Zengfu; Ye, Jian

    2017-01-01

    Seed size is a major determinant of seed yield but few is known about the genetics controlling of seed size in plants. Phytohormones cytokinin and brassinosteroid were known to be involved in the regulation of herbaceous plant seed development. Here we identified a homolog of Auxin Response Factor 19 (JcARF19) from a woody plant Jatropha curcas and genetically demonstrated its functions in controlling seed size and seed yield. Through Virus Induced Gene Silencing (VIGS), we found that JcARF19 was a positive upstream modulator in auxin signaling and may control plant organ size in J. curcas. Importantly, transgenic overexpression of JcARF19 significantly increased seed size and seed yield in plants Arabidopsis thaliana and J. curcas, indicating the importance of auxin pathway in seed yield controlling in dicot plants. Transcripts analysis indicated that ectopic expression of JcARF19 in J. curcas upregulated auxin responsive genes encoding essential regulators in cell differentiation and cytoskeletal dynamics of seed development. Our data suggested the potential of improving seed traits by precisely engineering auxin signaling in woody perennial plants. PMID:28102350

  2. Growing C4 perennial grass for bioenergy using a new Agro-BGC ecosystem model

    Science.gov (United States)

    di Vittorio, A. V.; Anderson, R. S.; Miller, N. L.; Running, S. W.

    2009-12-01

    Accurate, spatially gridded estimates of bioenergy crop yields require 1) biophysically accurate crop growth models and 2) careful parameterization of unavailable inputs to these models. To meet the first requirement we have added the capacity to simulate C4 perennial grass as a bioenergy crop to the Biome-BGC ecosystem model. This new model, hereafter referred to as Agro-BGC, includes enzyme driven C4 photosynthesis, individual live and dead leaf, stem, and root carbon/nitrogen pools, separate senescence and litter fall processes, fruit growth, optional annual seeding, flood irrigation, a growing degree day phenology with a killing frost option, and a disturbance handler that effectively simulates fertilization, harvest, fire, and incremental irrigation. There are four Agro-BGC vegetation parameters that are unavailable for Panicum virgatum (switchgrass), and to meet the second requirement we have optimized the model across multiple calibration sites to obtain representative values for these parameters. We have verified simulated switchgrass yields against observations at three non-calibration sites in IL. Agro-BGC simulates switchgrass growth and yield at harvest very well at a single site. Our results suggest that a multi-site optimization scheme would be adequate for producing regional-scale estimates of bioenergy crop yields on high spatial resolution grids.

  3. Effects on Environmental and Socioeconomic Sustainability of Producing Ethanol from Perennial Grasses

    Science.gov (United States)

    Dale, V. H.; Parish, E. S.

    2016-12-01

    Using perennial grasses to produce ethanol can enhance progress toward sustainability. A suite of 35 environmental and socioeconomic sustainability indicators was considered in a holistic sustainability assessment of a five-year switchgrass-to-ethanol production experiment centered on a demonstration-scale biorefinery in Vonore, Tennessee. By combining field measurements, literature review and expert opinion, the team was able to rate 28 of the 35 recommended sustainability indicators. The team combined these ratings within a multi-attribute decision support system tool and used this information to compare the sustainability of producing 2118 hectares of no-till switchgrass relative to two alternative business-as-usual scenarios of unmanaged pasture and tilled corn production. The results suggest that East Tennessee switchgrass production improves environmental quality overall and can be beneficial to the counties surrounding the biorefinery in terms of dollars earned and jobs created. The timing of switchgrass production also provides an opportunity to use inactive equipment and laborers. By incorporating a landscape design approach, the opportunities, constraints and most reasonable paths forward for growing bioenergy feedstock in specific context can be assessed in a way that adapts and improves local practices. Lessons learned from this case study are being incorporated into sustainability assessments of corn stover in Iowa and a variety of bioenergy feedstocks in diverse settings. The overall goal is to develop sound management practices that can address the multiple and sometimes competing demands of stakeholders.

  4. Modeling the Thickness of Perennial Ice Covers on Stratified Lakes of the Taylor Valley, Antarctica

    Science.gov (United States)

    Obryk, M. K.; Doran, P. T.; Hicks, J. A.; McKay, C. P.; Priscu, J. C.

    2016-01-01

    A one-dimensional ice cover model was developed to predict and constrain drivers of long term ice thickness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface radiative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 years (between 1996 and 2012) of ice thickness changes for west lobe of Lake Bonney (average ice thickness = 3.53 m; RMSE = 0.09 m, n = 118) and Lake Fryxell (average ice thickness = 4.22 m; RMSE = 0.21 m, n = 128). Long-term ice thickness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or facilitate ice thickness change depending on the predominant climatic trend (temperature cooling or warming). As such, shallow (< 20 m deep water columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation.

  5. Effect of Inhalation of Aromatherapy Oil on Patients with Perennial Allergic Rhinitis: A Randomized Controlled Trial

    Science.gov (United States)

    Choi, Seo Yeon

    2016-01-01

    This study aimed to investigate the effects of aromatherapy oil inhalation on symptoms, quality of life, sleep quality, and fatigue level among adults with perennial allergic rhinitis (PAR). Fifty-four men and women aged between 20 and 60 were randomized to inhale aromatherapy oil containing essential oil from sandalwood, geranium, and Ravensara or almond oil (the placebo) for 5 minutes twice daily for 7 days. PAR symptoms determined by Total Nasal Symptom Score (TNSS), the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), sleep quality by Verran Synder-Halpern (VSH) scale, and fatigue level by Chalder Fatigue Scale (CFS) were assessed before and after intervention period. Compared with the placebo, the experimental group showed significant improvement in TNSS, especially in nasal obstruction. The aromatherapy group also showed significantly higher improvements in total score of RQLQ and CFS. These findings indicate that inhalation of certain aromatherapy oil helps relieve PAR symptoms, improve rhinitis-specific quality of life, and reduce fatigue in patients with PAR. In conclusion, inhalation of aromatherapy essential oil may have potential as an effective intervention to alleviate PAR. PMID:27034695

  6. Facilitation influences patterns of perennial species abundance and richness in a subtropical dune system.

    Science.gov (United States)

    Dalotto, Cecilia E S; Sühs, Rafael B; Dechoum, Michele S; Pugnaire, Francisco I; Peroni, Nivaldo; Castellani, Tânia T

    2018-04-01

    Positive interactions in plant communities are under-reported in subtropical systems most likely because they are not identified as stressful environments. However, environmental factors or disturbance can limit plant growth in any system and lead to stressful conditions. For instance, salinity and low nutrient and water availability generate a gradient of stressful conditions in coastal systems depending on distance to shore. In a tropical coastal system in SE Brazil, we aimed to assess whether Guapira opposita , a shrub common in restinga environments, acted as nurse involved in ecological succession and which factors influenced its facilitation process. We sampled perennial species above 10 cm in height under the canopy of 35 G. opposita individuals and in neighbouring open areas. Shrub height, canopy area and distance to freshwater bodies were measured in the field, and distance to the ocean was obtained from aerial images. In addition, we measured the distance to the closest forest patch as a potential source of seeds. Plant abundance and species richness were higher under the canopy of G. opposita than in open areas. Facilitation by G. opposita was mainly determined by shrub height, which had a positive relationship with woody and bromeliads abundance and species richness while there was no relationship with the other factors. Overall, our data evidence that tropical environments may be highly stressful for plants and that nurse species play a key role in the regeneration of restinga environments, where their presence is critical to maintain ecosystem diversity and function.

  7. Beclomethasone Dipropionate Nasal Aerosol in Patients with Perennial Allergic Rhinitis (BALANCE) study: 6-month results.

    Science.gov (United States)

    Bukstein, Donald; Parikh, Ruchir; Eid, Sherrine; Ferro, Thomas; Morello, Jean-Pierre

    2016-01-01

    Perennial allergic rhinitis (PAR) exerts significant quality-of-life and economic burdens on society. Beclomethasone dipropionate (BDP) nasal aerosol is the first nonaqueous, hydrofluoroalkane-propelled intranasal corticosteroid approved for patients in the United States to treat PAR and seasonal allergic rhinitis. To evaluate real-world effectiveness of BDP nasal aerosol from the patient's perspective by using a postmarketing observational registry. Patients (N = 824) from 43 U.S. study sites completed monthly patient-reported outcome instruments, including the Rhinitis Control Assessment Test (primary outcome variable), Treatment Satisfaction Questionnaire for Medication, Work Productivity and Activity Impairment Questionnaire plus Classroom Impairment Questions: Allergy-Specific, Pittsburgh Sleep Quality Index, and Mini Rhinoconjunctivitis Quality of Life Questionnaire for 6 months. The primary outcome assessment (Rhinitis Control Assessment Test score) (N = 527) indicated significant symptomatic improvement over baseline beginning at month 1 (p 78.8% of respondents who achieved clinically meaningful improvement over 6 months. Secondary outcome measures Mini Rhinoconjunctivitis Quality of Life Questionnaire (p Work Productivity and Activity Impairment Questionnaire plus Classroom Impairment Questions: Allergy-Specific, with the exception of work time missed and class time missed, were significantly (p life, work, and school-related activities, and is associated with high patient satisfaction, reduced productivity loss and activity impairment, and improvement in sleep quality.

  8. Determinants of health disparities: The perennial struggle against polio in Nigeria

    Directory of Open Access Journals (Sweden)

    Nosayaba Osazuwa-Peters

    2011-01-01

    Full Text Available Polio remains a global public health issue, and even though it has been eradicated from most countries of the world, countries like Nigeria, the largest black nation on earth, threatens the dream of total eradication of polio from the surface of the earth. Transmission of wild polio virus has never been eliminated in Nigeria, but even worse is the number of countries, both in Sub-Saharan Africa and all over the world that has become re-infected by polio virus strains from Northern Nigeria in recent past. Although a lot has been documented about the Nigerian polio struggle, one aspect that has received little attention on this issue is ethnic and geographic disparities between the Southern and the Northern parts of Nigeria. Understanding these disparities involved in polio virus transmission in Nigeria, as well as the social determinants of health prevalent in Northern Nigeria will help government and other stakeholders and policy makers to synergize their efforts in the fight against this perennial scourge.

  9. Does polyembryony confer a competitive advantage to the invasive perennial vine Vincetoxicum rossicum (Apocynaceae)?

    Science.gov (United States)

    Blanchard, Megan L; Barney, Jacob N; Averill, Kristine M; Mohler, Charles L; Ditommaso, Antonio

    2010-02-01

    Determining which traits may allow some introduced plant species to become invasive in their new environment continues to be a key question in invasion biology. Vincetoxicum rossicum is an invasive, perennial vine colonizing natural and seminatural habitats primarily in the northeastern United States and southeastern Canada. More than half its seeds exhibit polyembryony, a relatively uncommon condition in which a single seed produces multiple seedlings. For evaluating the potential consequences of polyembryony on invasiveness, V. rossicum plants derived from seeds of three embryonic classes-singlets, doublets, and triplets (one, two, and three seedlings per seed, respectively)-were paired in all combinations intraspecifically and with the co-occurring native herbs Solidago canadensis and Asclepias syriaca in a greenhouse study. Vincetoxicum rossicum biomass was 25-55% greater and follicle production 55-100% greater under intraspecific competition compared with interspecific competition. However, within a competitive environment, follicle production varied little. Regardless of competitive environment, V. rossicum originating from seeds with a greater number of embryos typically performed no better than plants arising from seed with fewer embryos (singlets = doublets = triplets)-except intraspecifically where doublets outperformed singlets, and with S. canadensis where triplets outperformed singlets. Our findings suggest that overall performance and fitness of V. rossicum is higher in monocultures than in mixed stands and that its ability to invade new habitats may not be attributable to the production of polyembryonic seeds.

  10. Internal iron biomineralization in Imperata cylindrica, a perennial grass: chemical composition, speciation and plant localization.

    Science.gov (United States)

    Rodríguez, N; Menéndez, N; Tornero, J; Amils, R; de la Fuente, V

    2005-03-01

    * The analysis of metal distribution in Imperata cylindrica, a perennial grass isolated from the banks of Tinto River (Iberian Pyritic Belt), an extreme acidic environment with high content in metals, has shown a remarkable accumulation of iron. This property has been used to study iron speciation and its distribution among different tissues and structures of the plant. * Mossbauer (MS) and X-ray diffraction (XRD) were used to determine the iron species, scanning electron microscopy (SEM) to locate iron biominerals among plant tissue structures, and energy-dispersive X-ray microanalysis (EDAX), X-ray fluorescence (TXRF) and inductively coupled plasma emission spectroscopy (ICP-MS) to confirm their elemental composition. * The MS spectral analysis indicated that iron accumulated in this plant mainly as jarosite and ferritin. The presence of jarosite was confirmed by XRD and the distribution of both minerals in structures of different tissues was ascertained by SEM-EDAX analysis. * The convergent results obtained by complementary techniques suggest a complex iron management system in I. cylindrica, probably as a consequence of the environmental conditions of its habitat.

  11. Intraspecific competition facilitates the evolution of tolerance to insect damage in the perennial plant Solanum carolinense.

    Science.gov (United States)

    McNutt, David W; Halpern, Stacey L; Barrows, Kahaili; Underwood, Nora

    2012-12-01

    Tolerance to herbivory (the degree to which plants maintain fitness after damage) is a key component of plant defense, so understanding how natural selection and evolutionary constraints act on tolerance traits is important to general theories of plant-herbivore interactions. These factors may be affected by plant competition, which often interacts with damage to influence trait expression and fitness. However, few studies have manipulated competitor density to examine the evolutionary effects of competition on tolerance. In this study, we tested whether intraspecific competition affects four aspects of the evolution of tolerance to herbivory in the perennial plant Solanum carolinense: phenotypic expression, expression of genetic variation, the adaptive value of tolerance, and costs of tolerance. We manipulated insect damage and intraspecific competition for clonal lines of S. carolinense in a greenhouse experiment, and measured tolerance in terms of sexual and asexual fitness components. Compared to plants growing at low density, plants growing at high density had greater expression of and genetic variation in tolerance, and experienced greater fitness benefits from tolerance when damaged. Tolerance was not costly for plants growing at either density, and only plants growing at low density benefited from tolerance when undamaged, perhaps due to greater intrinsic growth rates of more tolerant genotypes. These results suggest that competition is likely to facilitate the evolution of tolerance in S. carolinense, and perhaps in other plants that regularly experience competition, while spatio-temporal variation in density may maintain genetic variation in tolerance.

  12. Effect of Inhalation of Aromatherapy Oil on Patients with Perennial Allergic Rhinitis: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    Seo Yeon Choi

    2016-01-01

    Full Text Available This study aimed to investigate the effects of aromatherapy oil inhalation on symptoms, quality of life, sleep quality, and fatigue level among adults with perennial allergic rhinitis (PAR. Fifty-four men and women aged between 20 and 60 were randomized to inhale aromatherapy oil containing essential oil from sandalwood, geranium, and Ravensara or almond oil (the placebo for 5 minutes twice daily for 7 days. PAR symptoms determined by Total Nasal Symptom Score (TNSS, the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ, sleep quality by Verran Synder-Halpern (VSH scale, and fatigue level by Chalder Fatigue Scale (CFS were assessed before and after intervention period. Compared with the placebo, the experimental group showed significant improvement in TNSS, especially in nasal obstruction. The aromatherapy group also showed significantly higher improvements in total score of RQLQ and CFS. These findings indicate that inhalation of certain aromatherapy oil helps relieve PAR symptoms, improve rhinitis-specific quality of life, and reduce fatigue in patients with PAR. In conclusion, inhalation of aromatherapy essential oil may have potential as an effective intervention to alleviate PAR.

  13. Differential Essential Oil Composition and Morphology between Perennial Satureja species Growing in Spain

    Directory of Open Access Journals (Sweden)

    David García-Rellán

    2015-06-01

    Full Text Available Chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of thirty six samples of perennial Spanish savouries (Satureja montana L., Satureja innota (Pau G. López, Satureja cuneifolia Ten. and Satureja intricata Lange, was investigated by GC and GC-MS. A total of 72 compounds accounting between 98.25-99.55% of the total oil were identified. High content of carvacrol (59.72±1.50% followed by g -terpinene (17.40±1.11% were found in S.montana essential oils. S. cuneifolia yielded an oil rich in camphor (45.04±1.67% and camphene (12.42±1.71% whereas S. innota produces an essential oil with linalool (23.94±7.58% or geraniol (8.62±3.45% according to the locality of collection and S. intricata showed chemical polymorphism with camphor (16.02±1.75%, as the main compound followed with populations with myrcene (8.46±1.46% and populations with g -terpinene (8.22±1.33%. Although the morphological affinity between S. innota, S.cuneifolia and S. intricata could lead to consider the subspecies level, the phytochemical discriminant analysis support the taxonomic classification of Flora Iberica which ranks these taxa into species.

  14. Facilitation influences patterns of perennial species abundance and richness in a subtropical dune system

    Science.gov (United States)

    Dalotto, Cecilia E S; Sühs, Rafael B; Dechoum, Michele S; Pugnaire, Francisco I; Peroni, Nivaldo; Castellani, Tânia T

    2018-01-01

    Abstract Positive interactions in plant communities are under-reported in subtropical systems most likely because they are not identified as stressful environments. However, environmental factors or disturbance can limit plant growth in any system and lead to stressful conditions. For instance, salinity and low nutrient and water availability generate a gradient of stressful conditions in coastal systems depending on distance to shore. In a tropical coastal system in SE Brazil, we aimed to assess whether Guapira opposita, a shrub common in restinga environments, acted as nurse involved in ecological succession and which factors influenced its facilitation process. We sampled perennial species above 10 cm in height under the canopy of 35 G. opposita individuals and in neighbouring open areas. Shrub height, canopy area and distance to freshwater bodies were measured in the field, and distance to the ocean was obtained from aerial images. In addition, we measured the distance to the closest forest patch as a potential source of seeds. Plant abundance and species richness were higher under the canopy of G. opposita than in open areas. Facilitation by G. opposita was mainly determined by shrub height, which had a positive relationship with woody and bromeliads abundance and species richness while there was no relationship with the other factors. Overall, our data evidence that tropical environments may be highly stressful for plants and that nurse species play a key role in the regeneration of restinga environments, where their presence is critical to maintain ecosystem diversity and function. PMID:29644027

  15. Floristic analysis of perennial species on flowerbeds in Belgrade with special attention on invasiveness of the recorded species

    Directory of Open Access Journals (Sweden)

    Popović Marija

    2012-01-01

    Full Text Available Urban areas are among the most important centres of invasive plant species distribution due to their richness in alien species. Because of that, a detailed floristic analysis of perennial flowerbeds was conducted in the central parks of Belgrade. A total of 53 perennial species were found, of which 55% were the alien species planted on 75% of the research area. Among them, two species (Aster novi belgii and Solidago canadensis are invasive and six species are potentially invasive in Serbia. These are planted on 5% and 20% of the flowerbeds, respectively. We can conclude that both the experts and institutions should be informed about the invasive species and potential damages. In the meantime, planting of native decorative species should be encouraged, since they will not pose a threat to natural habitats. Also, detailed research should be conducted in order to eradicate invasive and potentially invasive species from the surfaces around the research area.

  16. Composição botânica e estrutural e valor nutricional de pastagens de azevém consorciadas Botanic and structural composition and nutritional value on intercropped ryegrass pastures

    Directory of Open Access Journals (Sweden)

    Fernando Reimann Skonieski

    2011-03-01

    Full Text Available Neste trabalho objetivou-se avaliar a influência de espécies em consórcio com azevém sobre a composição botânica e estrutural e o valor nutritivo dos pastos em um sistema de transição agroecológica. Foi avaliada a cultura do azevém (Lolium multiflorum Lam. consorciada com aveia-preta (Avena strigosa Schreb., trevo-branco (Trifolium repens L. e amendoim-forrageiro (Arachis pintoi Krapov. & Gregory. O delineamento experimental foi o inteiramente casualizado, com três tratamentos e três repetições. O primeiro pastejo foi realizado 21 dias após a emergência das plantas nas pastagens de azevém + aveia-preta e azevém + amendoim-forrageiro e 28 dias após a emergência na pastagem de azevém + trevo-branco. O segundo pastejo na pastagem de azevém + aveia-preta ocorreu 30 dias após o primeiro pastejo, enquanto nas demais pastagens ocorreu 37 dias depois. As taxas de acúmulo de matéria seca (MS do início do período de exclusão até o pico de produção de MS foram de 77,7; 75,0 e 71,3 kg/ha/dia de MS para as pastagens consorciadas com trevo-branco, amendoim-forrageiro e aveia-preta, respectivamente. A razão folha/colmo até o segundo pastejo foi elevada em todas as pastagens. A redução dos teores de PB conforme os dias de exclusão no pasto de azevém + aveia-preta é menor que nos pastos de azevém consorciado com trevo-branco ou amendoim-forrageiro.The objective of this work was to evaluate the influence of species intercropped with ryegrass on the botanical and structural composition and the nutritional values of pastures in an agroecological transition system. It was evaluated ryegrass (Lolium multiflorum Lam. intercropped with black oats (Avena strigosa Schreb., white clover (Trifolium repens L. and forage peanut (Arachis pintoi Krapov. & Gregory. It was used a complete random design with three treatments and three repetitions. The first grazing was done 21 days after emergence of the plants on the pastures with ryegrass

  17. Seasonal/Interannual Variations of Carbon Sequestration and Carbon Emission in a Warm-Season Perennial Grassland

    OpenAIRE

    Deepa Dhital; Tomoharu Inoue; Hiroshi Koizumi

    2014-01-01

    Carbon sequestration and carbon emission are processes of ecosystem carbon cycling that can be affected while land area converted to grassland resulting in increased soil carbon storage and below-ground respiration. Discerning the importance of carbon cycle in grassland, we aimed to estimate carbon sequestration in photosynthesis and carbon emission in respiration from soil, root, and microbes, for four consecutive years (2007–2010) in a warm-season perennial grassland, Japan. Soil carbon emi...

  18. Seedbed preparation influence on morphometric characteristics of perennial grasses of a semi-arid rangeland in Kenya

    OpenAIRE

    Opiyo, Francis EO; Ekaya, Wellington N; Nyariki, Dickson M; Mureithi, Stephen Mwangi

    2011-01-01

    Semi-arid rangelands in Kenya are an important source of forage for both domestic and wild animals. However, indigenous perennial grasses notably Cenchrus ciliaris (African foxtail grass), Eragrostis superba (Maasai love grass) and Enteropogon macrostachyus (Bush rye grass) are disappearing at an alarming rate. Efforts to re-introduce them through restoration programs have often yielded little success. This can partly be attributed to failure of topsoil to capture and store scarce water to me...

  19. Ecosystem-service tradeoffs associated with switching from annual to perennial energy crops in riparian zones of the US Midwest.

    Directory of Open Access Journals (Sweden)

    Timothy D Meehan

    Full Text Available Integration of energy crops into agricultural landscapes could promote sustainability if they are placed in ways that foster multiple ecosystem services and mitigate ecosystem disservices from existing crops. We conducted a modeling study to investigate how replacing annual energy crops with perennial energy crops along Wisconsin waterways could affect a variety of provisioning and regulating ecosystem services. We found that a switch from continuous corn production to perennial-grass production decreased annual income provisioning by 75%, although it increased annual energy provisioning by 33%, decreased annual phosphorous loading to surface water by 29%, increased below-ground carbon sequestration by 30%, decreased annual nitrous oxide emissions by 84%, increased an index of pollinator abundance by an average of 11%, and increased an index of biocontrol potential by an average of 6%. We expressed the tradeoffs between income provisioning and other ecosystem services as benefit-cost ratios. Benefit-cost ratios averaged 12.06 GJ of additional net energy, 0.84 kg of avoided phosphorus pollution, 18.97 Mg of sequestered carbon, and 1.99 kg of avoided nitrous oxide emissions for every $1,000 reduction in income. These ratios varied spatially, from 2- to 70-fold depending on the ecosystem service. Benefit-cost ratios for different ecosystem services were generally correlated within watersheds, suggesting the presence of hotspots--watersheds where increases in multiple ecosystem services would come at lower-than-average opportunity costs. When assessing the monetary value of ecosystem services relative to existing conservation programs and environmental markets, the overall value of enhanced services associated with adoption of perennial energy crops was far lower than the opportunity cost. However, when we monitized services using estimates for the social costs of pollution, the value of enhanced services far exceeded the opportunity cost. This

  20. DIMENSIONS OF CARCASS AND INTERNAL ORGANS IN YOUNG SHEEP, UNDER CONDITIONS OF GRAZING ON ASSOCIATIONS OF PERENNIAL GRAMINACEOUS AND LEGUME

    Directory of Open Access Journals (Sweden)

    N. DRAGOMIR

    2009-05-01

    Full Text Available The temporary pastures’ floristic structure influences directly the growth and development of young sheep during grazing. The associations, beside the graminaceous and perennial legume species (white clover and birdsfoot trefoil, contribute mostly to the increase of carcass dimension and organ weight. The quality of the forage from such a pasture, better balanced in terms of energy and protein, influences all growth and development parameters in young sheep.

  1. Study of Potential and Real Seed Producing Capacity in Some Romanian Varieties of Legumes and Perennial Gramineae

    Directory of Open Access Journals (Sweden)

    Neculai Dragomir

    2010-10-01

    Full Text Available This work presents the potential and real seed producing capacity in some Romanian varieties of legumes and perennial gramineae: Trifolium repens, Lotus corniculatus, Lolium perenne, Festuca pratensis, Festuca arundinacea and Dactylis glomerata. To calculate the potential production, we performed determinations and analyses on each variety, regarding floral apparatus’ morphological and anatomic structure (number of inflorescences, number of flowers, number of ovules/ovary, and the real production was determined „in situ”.

  2. Environmental Performance of Miscanthus, Switchgrass and Maize: Can C4 Perennials Increase the Sustainability of Biogas Production?

    Directory of Open Access Journals (Sweden)

    Andreas Kiesel

    2016-12-01

    Full Text Available Biogas is considered a promising option for complementing the fluctuating energy supply from other renewable sources. Maize is currently the dominant biogas crop, but its environmental performance is questionable. Through its replacement with high-yielding and nutrient-efficient perennial C4 grasses, the environmental impact of biogas could be considerably improved. The objective of this paper is to assess and compare the environmental performance of the biogas production and utilization of perennial miscanthus and switchgrass and annual maize. An LCA was performed using data from field trials, assessing the impact in the five categories: climate change (CC, fossil fuel depletion (FFD, terrestrial acidification (TA, freshwater eutrophication (FE and marine eutrophication (ME. A system expansion approach was adopted to include a fossil reference. All three crops showed significantly lower CC and FFD potentials than the fossil reference, but higher TA and FE potentials, with nitrogen fertilizer production and fertilizer-induced emissions identified as hot spots. Miscanthus performed best and changing the input substrate from maize to miscanthus led to average reductions of −66% CC; −74% FFD; −63% FE; −60% ME and −21% TA. These results show that perennial C4 grasses and miscanthus in particular have the potential to improve the sustainability of the biogas sector.

  3. Effect of Repeated Application of Manure on Herbage Yield, Quality and Wintering Ability during Cropping of Dwarf Napiergrass with Italian Ryegrass in Hilly Southern Kyushu, Japan

    Directory of Open Access Journals (Sweden)

    Renny Fatmyah Utamy

    2018-03-01

    Full Text Available The effects of two levels of manure application (184 and 275 kg N ha−1 year−1 on herbage yield, quality, and wintering ability during the cropping of a dwarf genotype of late-heading (DL Napiergrass (Pennisetum purpureum Schumach oversown with Italian ryegrass (IR; Lolium multiflorum Lam. were examined and compared with chemical fertilizer application (234 kg N ha−1 year−1 for 4 years to determine a sustainable and environmentally harmonized herbage production in a hilly area (340 m above sea level. No significant (p > 0.05 differences in growth attributes of plant height, tiller density, percentage of leaf blade, or dry matter yield appeared in either DL Napiergrass or IR among moderate levels (184–275 kg N ha−1 year−1 of manure and chemical fertilizer treatments. IR exhibited no significant detrimental effect on spring regrowth of DL Napiergrass, which showed a high wintering ability in all treatments. In vitro dry matter digestibility of DL Napiergrass tended to increase with increasing manure application, especially at the first defoliation in the first three years. Manure application improved soil chemical properties and total nitrogen and carbon content. The results suggested that the lower rate of manure application of 184 kg nitrogen ha−1 year−1 would be suitable, which would be a good substitute for chemical fertilizer application with an equilibrium nitrogen budget for sustainable DL Napiergrass and IR cropping in the hilly region of southern Kyushu.

  4. In-vitro assessment of the probiotic potential of Lactobacillus plantarum KCC-24 isolated from Italian rye-grass (Lolium multiflorum) forage.

    Science.gov (United States)

    Vijayakumar, Mayakrishnan; Ilavenil, Soundharrajan; Kim, Da Hye; Arasu, Mariadhas Valan; Priya, Kannappan; Choi, Ki Choon

    2015-04-01

    The aim of the present study was to determine the probiotic potential of the lactic acid bacteria Lactobacillus plantarum KCC-24 (L. plantarum KCC-24), that was isolated and characterized from Italian ryegrass (Lolium multiflorum) forage. The following experiments were performed to assess the probiotic characteristics such as antifungal activity, antibiotic susceptibility, resistance to low pH, stimulated gastric juice and bile salts, proteolytic activity, auto-aggregation, cell surface hydrophobicity, and in vitro antioxidant property. The isolated L. plantarum KCC-24 exhibited significant antifungal activity against the various fungal strains of Aspergillus fumigatus (73.43%), Penicillium chrysogenum (59.04%), Penicillium roqueforti (56.67%), Botrytis elliptica (40.23%), Fusarium oxysporum (52.47%) and it was susceptible to numerous antibiotics, survived in low pH, was resistant to stimulated gastric juices and bile salts (0.3% w/v). Moreover, L. plantarum KCC-24 exhibited good proteolytic activity. In addition L. plantarum KCC-24 showed potent antioxidant and hydrogen peroxide resistant property. In conclusion, the isolated L. plantarum KCC-24 exhibited several characteristics to prove it's excellent as a potential probiotic candidate for developing quality food for ruminant animals and human. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Forage yield and nutritive value of Elephant grass, Italian ryegrass and spontaneous growing species mixed with forage peanut or red clover

    Directory of Open Access Journals (Sweden)

    Michelle Schalemberg Diehl

    2014-10-01

    Full Text Available The objective of this research was to evaluate of three grazing systems (GS with elephant grass (EG, Italian ryegrass (IR + spontaneous growing species (SGS; EG + IR + SGS + forage peanut (FP; and EG + IR + SGS + red clover (RC, during the winter and summer periods in rotational grazing with dairy cattle. Experimental design was completely randomized with three treatments, two replicates with repeated measures. Lactating Holstein cows receiving 1% BW-daily feed supplement with concentrate were used in the evaluation. Eight grazing cycles were performed during the experimental period. The values of pre forage mass and stocking rate were 2.52, 2.60 and 2.99 t ha-1 and 2.64, 2.77 and 3.14 animal unit ha-1, respectively for GS. Samples of forage were collected by hand-plucking technique to analyze the crude protein (CP, neutral detergent fiber (NDF, in situ dry matter digestibility (ISDMD, in situ organic matter digestibility (ISOMD of forage present between rows of elephant grass, in the rows of elephant grass and the legumes. Higher value of CP, ISOMD and lower of NDF were observed for the grazing systems mixed with legumes forage.

  6. Epigenetic variation predicts regional and local intraspecific functional diversity in a perennial herb.

    Science.gov (United States)

    Medrano, Mónica; Herrera, Carlos M; Bazaga, Pilar

    2014-10-01

    The ecological significance of epigenetic variation has been generally inferred from studies on model plants under artificial conditions, but the importance of epigenetic differences between individuals as a source of intraspecific diversity in natural plant populations remains essentially unknown. This study investigates the relationship between epigenetic variation and functional plant diversity by conducting epigenetic (methylation-sensitive amplified fragment length polymorphisms, MSAP) and genetic (amplified fragment length polymorphisms, AFLP) marker-trait association analyses for 20 whole-plant, leaf and regenerative functional traits in a large sample of wild-growing plants of the perennial herb Helleborus foetidus from ten sampling sites in south-eastern Spain. Plants differed widely in functional characteristics, and exhibited greater epigenetic than genetic diversity, as shown by per cent polymorphism of MSAP fragments (92%) or markers (69%) greatly exceeding that for AFLP ones (41%). After controlling for genetic structuring and possible cryptic relatedness, every functional trait considered exhibited a significant association with at least one AFLP or MSAP marker. A total of 27 MSAP (13.0% of total) and 12 AFLP (4.4%) markers were involved in significant associations, which explained on average 8.2% and 8.0% of trait variance, respectively. Individual MSAP markers were more likely to be associated with functional traits than AFLP markers. Between-site differences in multivariate functional diversity were directly related to variation in multilocus epigenetic diversity after multilocus genetic diversity was statistically accounted for. Results suggest that epigenetic variation can be an important source of intraspecific functional diversity in H. foetidus, possibly endowing this species with the capacity to exploit a broad range of ecological conditions despite its modest genetic diversity. © 2014 John Wiley & Sons Ltd.

  7. Genomic selection prediction accuracy in a perennial crop: case study of oil palm (Elaeis guineensis Jacq.).

    Science.gov (United States)

    Cros, David; Denis, Marie; Sánchez, Leopoldo; Cochard, Benoit; Flori, Albert; Durand-Gasselin, Tristan; Nouy, Bruno; Omoré, Alphonse; Pomiès, Virginie; Riou, Virginie; Suryana, Edyana; Bouvet, Jean-Marc

    2015-03-01

    Genomic selection empirically appeared valuable for reciprocal recurrent selection in oil palm as it could account for family effects and Mendelian sampling terms, despite small populations and low marker density. Genomic selection (GS) can increase the genetic gain in plants. In perennial crops, this is expected mainly through shortened breeding cycles and increased selection intensity, which requires sufficient GS accuracy in selection candidates, despite often small training populations. Our objective was to obtain the first empirical estimate of GS accuracy in oil palm (Elaeis guineensis), the major world oil crop. We used two parental populations involved in conventional reciprocal recurrent selection (Deli and Group B) with 131 individuals each, genotyped with 265 SSR. We estimated within-population GS accuracies when predicting breeding values of non-progeny-tested individuals for eight yield traits. We used three methods to sample training sets and five statistical methods to estimate genomic breeding values. The results showed that GS could account for family effects and Mendelian sampling terms in Group B but only for family effects in Deli. Presumably, this difference between populations originated from their contrasting breeding history. The GS accuracy ranged from -0.41 to 0.94 and was positively correlated with the relationship between training and test sets. Training sets optimized with the so-called CDmean criterion gave the highest accuracies, ranging from 0.49 (pulp to fruit ratio in Group B) to 0.94 (fruit weight in Group B). The statistical methods did not affect the accuracy. Finally, Group B could be preselected for progeny tests by applying GS to key yield traits, therefore increasing the selection intensity. Our results should be valuable for breeding programs with small populations, long breeding cycles, or reduced effective size.

  8. Transcriptome Analysis in Sheepgrass (Leymus chinensis). A Dominant Perennial Grass of the Eurasian Steppe

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuangyan [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing; Huang, Xin [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing; Yang, Xiaohan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Liu, Gongshe [Chinese Academy of Sciences (CAS), Institute of Botany (IB), Beijing

    2013-07-04

    BACKGROUND: Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. RESULTS: The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. CONCLUSIONS: This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

  9. Soil Compressibility under Irrigated Perennial and Annual Crops in a Semi-Arid Environment

    Directory of Open Access Journals (Sweden)

    Rafaela Watanabe

    Full Text Available ABSTRACT In irrigated soils, a continuous state of high moisture reduces resistance of the soil to applied external forces, favouring compaction. The aim of this study was to evaluate the susceptibility to compaction of developed calcareous soils in irrigated annual and perennial cropping systems of the Apodi Plateau, located in the Brazilian semi-arid region. Four areas of irrigated crops were evaluated: banana after two (B2 and 15 (B15 years cultivation, pasture (P, and a corn and beans succession (MB, as well as the reference areas for soil quality and corresponding natural vegetation (NVB2, NVB15, NVP and NVMB. Samples were collected at layers of 0.00-0.10 and 0.20-0.30 m; and for B2 and B15, samples were collected in the row and inter-row spaces. The following properties were determined: degree of compactness (DC, preconsolidation pressure (σp, compression index (Cc, maximum density (ρmax, critical water content (WCcrit, total organic carbon (TOC and carbon of light organic matter (Clom. Mean values were compared by the t-test at 5, 10, 15 and 20 % probability. An increase was seen in DC at a layer of 0.20-0.30 m in MB (p<0.15, showing the deleterious effects of preparing the soil by ploughing and chiselling, together with the cumulative traffic of heavy machinery. The TOC had a greater influence on ρmax than the stocks of Clom. Irrigation caused a reduction in Cc, and there was no effect on σp at field capacity. The planting rows showed different behaviour for Cc, ρmax, and WCcrit,, and in general the physical properties displayed better conditions than the inter-row spaces. Values for σp and Cc showed that agricultural soils display greater load-bearing capacity and are less susceptible to compaction in relation to soils under natural vegetation.

  10. One hundred and six years of population and community dynamics of Sonoran Desert Laboratory perennials

    Science.gov (United States)

    Rodriguez-Buritica, Susana; Raichle, Helen; Webb, Robert H.; Turner, Raymond M.; Venable, Larry

    2013-01-01

    This data set constitutes all information associated with the Spalding-Shreve permanent vegetation plots from 1906 through 2012, which is the longest-running plant monitoring program in the world. The program consists of detailed maps of all Sonoran Desert perennial plants in 30 permanent plots located on Tumamoc Hill, near Tucson, Arizona, USA. Most of these plots are 10 m × 10 m quadrats that were established by Volney Spalding and Forrest Shreve between 1906 and 1928. Analyses derived from these data have been pivotal in testing early theories on plant community succession, plant life history traits, plant longevity, and population dynamics. One of the major contributions of this data set is the species-specific demographic traits that derived from estimating individual plant trajectories for more than 106 years. Further use of these data might shed light on spatially explicit population and community dynamics, as well as long-term changes attributable to global change. Data presented here consist of digital versions of original maps created between 1906 and 1984 and digital data from recent censuses between 1993 and 2012. Attributes associated with these maps include location and coverage of all shrubs, and in some cases, plant height. In addition, we present plot-specific summaries of plant cover and density for each census year and all other information collected, including seedling counts, grass coverage, and annual species enumerations. We reference the repeat photography of these plots, which began in 1906; these images are stored at the Desert Laboratory Collection of Repeat Photography in Tucson. Initial data collection consisted of grid-mapping the plots manually on graph paper; starting in 1993, Total Stations (which allow a direct digitalization, and more accurate mapping) were used to survey root crowns and canopies.

  11. Plant-Herbivore and Plant-Pollinator Interactions of the Developing Perennial Oilseed Crop, Silphium integrifolium.

    Science.gov (United States)

    Prasifka, J R; Mallinger, R E; Hulke, B S; Larson, S R; Van Tassel, D

    2017-12-08

    Sampling in Kansas and North Dakota documented the plant-herbivore and plant-pollinator interactions of the developing perennial oilseed crop, Silphium integrifolium Michx. The larva of the tortricid moth, Eucosma giganteana (Riley), was the most damaging floret- and seed-feeding pest in Kansas, with infested heads producing ≈85% (2015) or ≈45% (2016) fewer seeds than apparently undamaged heads. Necrosis of apical meristems caused stunting and delayed bloom in Kansas; though the source of the necrosis is not known, observations of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois; Hemiptera: Miridae), in S. integrifolium terminals suggest a possible cause. In North Dakota, E. giganteana larvae were not found, but pupae of Neotephritis finalis (Loew; Diptera: Tephritidae), a minor pest of cultivated sunflower, were common in the heads of S. integrifolium. Bees appeared highly attracted to S. integrifolium, and in all but one observation, bees were seen actively collecting pollen. The most common bees included large apids (Apis mellifera L., Svastra obliqua [Say], Melissodes spp.) and small-bodied halictids (Lasioglossum [Dialictus] spp.). Controlled pollination experiments demonstrated that S. integrifolium is pollinator dependent, due to both mechanical barriers (imperfect florets and protogyny) and genetic self-incompatibility. Subsequent greenhouse tests and AFLP confirmation of putative self-progeny show that a low (<1%) level of self-pollination is possible. If genetic self-incompatibility is eventually reduced through breeding, mechanical barriers would maintain a reliance on bees to move pollen between male and female florets. Collectively, observations on S. integrifolium show that both herbivore and pollinator management are important to maximize seed production. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  12. Targeted mutagenesis using zinc-finger nucleases in perennial fruit trees.

    Science.gov (United States)

    Peer, Reut; Rivlin, Gil; Golobovitch, Sara; Lapidot, Moshe; Gal-On, Amit; Vainstein, Alexander; Tzfira, Tzvi; Flaishman, Moshe A

    2015-04-01

    Targeting a gene in apple or fig with ZFN, introduced by transient or stable transformation, should allow genome editing with high precision to advance basic science and breeding programs. Genome editing is a powerful tool for precise gene manipulation in any organism; it has recently been shown to be of great value for annual plants. Classical breeding strategies using conventional cross-breeding and induced mutations have played an important role in the development of new cultivars in fruit trees. However, fruit-tree breeding is a lengthy process with many limitations. Efficient and widely applied methods for targeted modification of fruit-tree genomes are not yet available. In this study, transgenic apple and fig lines carrying a zinc-finger nuclease (ZFNs) under the control of a heat-shock promoter were developed. Editing of a mutated uidA gene, following expression of the ZFN genes by heat shock, was confirmed by GUS staining and PCR product sequencing. Finally, whole plants with a repaired uidA gene due to deletion of a stop codon were regenerated. The ZFN-mediated gene modifications were stable and passed onto regenerants from ZFN-treated tissue cultures. This is the first demonstration of efficient and precise genome editing, using ZFN at a specific genomic locus, in two different perennial fruit trees-apple and fig. We conclude that targeting a gene in apple or fig with a ZFN introduced by transient or stable transformation should allow knockout of a gene of interest. Using this technology for genome editing allows for marker gene-independent and antibiotic selection-free genome engineering with high precision in fruit trees to advance basic science as well as nontransgenic breeding programs.

  13. Transcriptome analysis in sheepgrass (Leymus chinensis): a dominant perennial grass of the Eurasian Steppe.

    Science.gov (United States)

    Chen, Shuangyan; Huang, Xin; Yan, Xueqing; Liang, Ye; Wang, Yuezhu; Li, Xiaofeng; Peng, Xianjun; Ma, Xingyong; Zhang, Lexin; Cai, Yueyue; Ma, Tian; Cheng, Liqin; Qi, Dongmei; Zheng, Huajun; Yang, Xiaohan; Li, Xiaoxia; Liu, Gongshe

    2013-01-01

    Sheepgrass [Leymus chinensis (Trin.) Tzvel.] is an important perennial forage grass across the Eurasian Steppe and is known for its adaptability to various environmental conditions. However, insufficient data resources in public databases for sheepgrass limited our understanding of the mechanism of environmental adaptations, gene discovery and molecular marker development. The transcriptome of sheepgrass was sequenced using Roche 454 pyrosequencing technology. We assembled 952,328 high-quality reads into 87,214 unigenes, including 32,416 contigs and 54,798 singletons. There were 15,450 contigs over 500 bp in length. BLAST searches of our database against Swiss-Prot and NCBI non-redundant protein sequences (nr) databases resulted in the annotation of 54,584 (62.6%) of the unigenes. Gene Ontology (GO) analysis assigned 89,129 GO term annotations for 17,463 unigenes. We identified 11,675 core Poaceae-specific and 12,811 putative sheepgrass-specific unigenes by BLAST searches against all plant genome and transcriptome databases. A total of 2,979 specific freezing-responsive unigenes were found from this RNAseq dataset. We identified 3,818 EST-SSRs in 3,597 unigenes, and some SSRs contained unigenes that were also candidates for freezing-response genes. Characterizations of nucleotide repeats and dominant motifs of SSRs in sheepgrass were also performed. Similarity and phylogenetic analysis indicated that sheepgrass is closely related to barley and wheat. This research has greatly enriched sheepgrass transcriptome resources. The identified stress-related genes will help us to decipher the genetic basis of the environmental and ecological adaptations of this species and will be used to improve wheat and barley crops through hybridization or genetic transformation. The EST-SSRs reported here will be a valuable resource for future gene-phenotype studies and for the molecular breeding of sheepgrass and other Poaceae species.

  14. Contrasts in Sea Ice Formation and Production in the Arctic Seasonal and Perennial Ice Zones

    Science.gov (United States)

    Kwok, R.

    2006-01-01

    Four years (1997-2000) of RADARSAT Geophysical Processor System (RGPS) data are used to contrast the sea ice deformation and production regionally, and in the seasonal (SIZ) and perennial (PIZ) ice zones. Ice production is of seasonal ice in openings during the winter. 3-day estimates of these quantities are provided within Lagrangian elements initially 10 km on a side. A distinct seasonal cycle is seen in both zones with these estimates highest in the late fall and with seasonal minimums in the mid-winter. Regional divergence over the winter could be up to 30%. Spatially, the highest deformation is in the SIZ north of coastal Alaska. Both ice deformation and production are higher in the SIZ: deformation-related ice production in the SIZ (approx.0.5 m) is 1.5-2.3 times that of the PIZ (approx.0.3 m) - this is connected to ice strength and thickness. Atmospheric forcing and boundary layer structure contribute to only the seasonal and interannual variability. Seasonal ice growth in ice fractures accounts for approx.25-40% of the total ice production of the Arctic Ocean. By itself, this deformation-ice production relationship could be considered a negative feedback when thickness is perturbed. However, the overall effect on ice production in the face of increasing seasonal and thinner/weaker ice coverage could be modified by: local destabilization of the water column promoting overturning of warmer water due to increased brine rejection; and, the upwelling of the pynocline associated with increased occurrence of large shear motion in sea ice.

  15. A feasibility study of perennial/annual plant species to restore soils contaminated with heavy metals

    Science.gov (United States)

    Zacarías, Montserrat; Beltrán, Margarita; Gilberto Torres, Luis; González, Abelardo

    A feasibility study was carried out to evaluate the application of perennial/annual plant species in a phytoextraction process of a previously washed industrial urban soil contaminated by nickel, arsenic and cupper. The plant species selected for this study were Ipomea (Ipomea variada); grass (Poa pratensis); grass mixture (Festuca rubra, Cynodon dactylon, Lolium multiforum, Pennisetum sp.); Monks Cress (Tropaeolum majus); ficus (Ficus benajamina) and fern (Pteris cretica). Soil was characterized and it presented the following heavy metals concentrations (dry weight): 80 mg of Ni/kg, 456-656 mg of As/kg and 1684-3166 mg of Cu/kg. Germination and survival in contaminated soil tests were conducted, from these, P. pratensis was discarded and the rest of plant species tested were used for the phytoextraction selection test. After 4 months of growth, biomass production was determined, and content of Ni, As and Cu was analyzed in plant’s tissue. Metal biological absorption coefficient (BAC), bio-concentration factor (BCF) and translocation factor (TF), were calculated. Regarding to biomass generation it was observed, in every case, an inhibition of the plant growth compared with blanks sown in a non contaminated soil; inhibition ranged from 22.5% for the Monk cress to 98% for Ipomea. Even though the later presented high BAC, BCF and TF, its growth was severely inhibited, and therefore, due its low biomass generation, it is not recommended for phytoextraction under conditions for this study. Heavy metals concentrations in plant’s tissue (dry weight) were as high as 866 mg Cu/kg and 602 mg As/kg for grass mixture; and 825 mg As/kg was observed for Monks cress. Grass mixture and monks cress had high BAC, BCF and TF, also they had high metal concentrations in its plants tissues and the lowest growth inhibition rates; hence the application in phytoextraction processes of these plants is advisable.

  16. Non-perennial Mediterranean rivers in Europe: Status, pressures, and challenges for research and management.

    Science.gov (United States)

    Skoulikidis, Nikolaos T; Sabater, Sergi; Datry, Thibault; Morais, Manuela M; Buffagni, Andrea; Dörflinger, Gerald; Zogaris, Stamatis; Del Mar Sánchez-Montoya, Maria; Bonada, Nuria; Kalogianni, Eleni; Rosado, Joana; Vardakas, Leonidas; De Girolamo, Anna Maria; Tockner, Klement

    2017-01-15

    Non-perennial rivers and streams (NPRS) cover >50% of the global river network. They are particularly predominant in Mediterranean Europe as a result of dry climate conditions, climate change and land use development. Historically, both scientists and policy makers underestimated the importance of NRPS for nature and humans alike, mainly because they have been considered as systems of low ecological and economic value. During the past decades, diminishing water resources have increased the spatial and temporal extent of artificial NPRS as well as their exposure to multiple stressors, which threatening their ecological integrity, biodiversity and ecosystem services. In this paper, we provide a comprehensive overview of the structural and functional characteristics of NPRS in the European Mediterranean, and discuss gaps and problems in their management, concerning their typology, ecological assessment, legislative and policy protection, and incorporation in River Basin Management Plans. Because NPRS comprise highly unstable ecosystems, with strong and often unpredictable temporal and spatial variability - at least as far as it is possible to assess - we outline the future research needs required to better understand, manage and conserve them as highly valuable and sensitive ecosystems. Efficient collaborative activities among multidisciplinary research groups aiming to create innovative knowledge, water managers and policy makers are urgently needed in order to establish an appropriate methodological and legislative background. The incorporation of NPRS in EU-Med River Basin Management Plans in combination with the application of ecological flows is a first step towards enhancing NPRS management and conservation in order to effectively safeguard these highly valuable albeit threatened ecosystems. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Soil denitrifier community size changes with land use change to perennial bioenergy cropping systems

    Science.gov (United States)

    Thompson, Karen A.; Deen, Bill; Dunfield, Kari E.

    2016-10-01

    Dedicated biomass crops are required for future bioenergy production. However, the effects of large-scale land use change (LUC) from traditional annual crops, such as corn-soybean rotations to the perennial grasses (PGs) switchgrass and miscanthus, on soil microbial community functioning is largely unknown. Specifically, ecologically significant denitrifying communities, which regulate N2O production and consumption in soils, may respond differently to LUC due to differences in carbon (C) and nitrogen (N) inputs between crop types and management systems. Our objective was to quantify bacterial denitrifying gene abundances as influenced by corn-soybean crop production compared to PG biomass production. A field trial was established in 2008 at the Elora Research Station in Ontario, Canada (n  =  30), with miscanthus and switchgrass grown alongside corn-soybean rotations at different N rates (0 and 160 kg N ha-1) and biomass harvest dates within PG plots. Soil was collected on four dates from 2011 to 2012 and quantitative PCR was used to enumerate the total bacterial community (16S rRNA) and communities of bacterial denitrifiers by targeting nitrite reductase (nirS) and N2O reductase (nosZ) genes. Miscanthus produced significantly larger yields and supported larger nosZ denitrifying communities than corn-soybean rotations regardless of management, indicating large-scale LUC from corn-soybean to miscanthus may be suitable in variable Ontario climatic conditions and under varied management, while potentially mitigating soil N2O emissions. Harvesting switchgrass in the spring decreased yields in N-fertilized plots, but did not affect gene abundances. Standing miscanthus overwinter resulted in higher 16S rRNA and nirS gene copies than in fall-harvested crops. However, the size of the total (16S rRNA) and denitrifying bacterial communities changed differently over time and in response to LUC, indicating varying controls on these communities.

  18. INGESTIVE BEHAVIOR OF GOATS IN RYEGRASS AND BLACK OAT PASTURES IN PURE OR MIXTURE CULTURE COMPORTAMENTO INGESTIVO DE CAPRINOS EM PASTAGEM DE AZEVÉM E AVEIA PRETA EM CULTIVO PURO E CONSORCIADO

    Directory of Open Access Journals (Sweden)

    Alda Lúcia Gomes Monteiro

    2009-07-01

    Full Text Available The experiment was realized in Campo Largo, PR, where the ingestive behavior of goats was evaluated under ryegrass (Lolium multiflorum Lam. and black oat (Avena strigosa Schreb pastures in pure or mixture culture, in the period of 04/07/2004 to 05/08/2004. The grasses were applied in poles of 630 m² each, and the experimental design was placed in randomized blocks with three treatments and three repetitions. Twelve female goats were distributed in three experimental poles with four goats each for grazing evaluations. Previously to the evaluations of the animals the measurements of the pasture were obtained, which included height, total mass of forage and of the compounds leaf and steam. The goats were evaluated by preference and ingestion rate. The averages of pastures height was higher (p>0.05 in ryegrass and mixture, and in other pastures evaluations ryegrass was superior (p<0.05 to the others treatments. The grazing time of goats in ryegrass and black oat was superior (p<0.05 to the mixture. The bite rate per minute was higher (p<0.05 in black oat. The goats demonstrated preference for ryegrass and black oat in pure culture.
     
    KEY WORDS: Avena strigosa Schreb, bite, goats, Lolium multiflorum Lam, preference. The experiment was realized in Campo Largo – PR, where the ingestive behavior of goats was evaluated under ryegrass (Lolium multiflorum Lam. and black oat (Avena strigosa Schreb pastures in pure or mixture culture, in the period of 04/07/2004 to 05/08/2004. The grasses were applied in poles of 630 m² each, and the experimental design was placed in randomized blocks with three treatments and three repetitions. Twelve female goats were distributed in three experimental poles with four goats each for grazing evaluations. Previously to the evaluations of the animals the measurements of the pasture were obtained, which included height, total mass of forage and of the compounds leaf and steam. The goats were evaluated by

  19. More milk from forage: Milk production, blood metabolites, and forage intake of dairy cows grazing pasture mixtures and spatially adjacent monocultures.

    Science.gov (United States)

    Pembleton, Keith G; Hills, James L; Freeman, Mark J; McLaren, David K; French, Marion; Rawnsley, Richard P

    2016-05-01

    There is interest in the reincorporation of legumes and forbs into pasture-based dairy production systems as a means of increasing milk production through addressing the nutritive value limitations of grass pastures. The experiments reported in this paper were undertaken to evaluate milk production, blood metabolite concentrations, and forage intake levels of cows grazing either pasture mixtures or spatially adjacent monocultures containing perennial ryegrass (Lolium perenne), white clover (Trifolium repens), and plantain (Plantago lanceolata) compared with cows grazing monocultures of perennial ryegrass. Four replicate herds, each containing 4 spring-calving, cross-bred dairy cows, grazed 4 different forage treatments over the periods of early, mid, and late lactation. Forage treatments were perennial ryegrass monoculture (PRG), a mixture of white clover and plantain (CPM), a mixture of perennial ryegrass, white clover, and plantain (RCPM), and spatially adjacent monocultures (SAM) of perennial ryegrass, white clover, and plantain. Milk volume, milk composition, blood fatty acids, blood β-hydroxybutyrate, blood urea N concentrations, live weight change, and estimated forage intake were monitored over a 5-d response period occurring after acclimation to each of the forage treatments. The acclimation period for the early, mid, and late lactation experiments were 13, 13, and 10 d, respectively. Milk yield (volume and milk protein) increased for cows grazing the RCPM and SAM in the early lactation experiment compared with cows grazing the PRG, whereas in the mid lactation experiment, milk fat increased for the cows grazing the RCPM and SAM when compared with the PRG treatments. Improvements in milk production from grazing the RCPM and SAM treatments are attributed to improved nutritive value (particularly lower neutral detergent fiber concentrations) and a potential increase in forage intake. Pasture mixtures or SAM containing plantain and white clover could be a

  20. Bioestadística en cultivos Perennes Biostatistics in Perennial crops

    Directory of Open Access Journals (Sweden)

    Martínez B. Ricardo

    1989-12-01

    varios períodos de tiempo sobre las mismas plantas. El análisis estadístico debe tener en cuenta esto y por lo tanto se sugieren algunos métodos de trabajo.Perennial crops live longer than annual crops, and since they are likely to be larger, experiments with them face special problems. The experiments often taken several years, so the plants are at risk longer, increasing the likelihood of mishap and thus unbalanced data, so greater caution is needed in making plants about them. The experimental design must be able to tolerate the inevitable missing data. Whatever design is used, it must be throughly practicable, for it is no use producing a scheme on paper that will give endless trouble in the field. Experimental objetives may change over time, requiring modification of the original study plan. It is better simple experimental design than complex ones, these are inflexible and are seriously undermined by missing data in both computation and interpretation. Since perennials are in general larger than annuals are of greater interest as individuals, and will probably use single.plant or several
    plant plots, and environmental variation in rarely of sole importance. With perennials the experimenter should not assume de error variation as positional, Le envirenmental,
    some of it may well derive from the plants themselves.
    Attempting to reduce error variance by merely increasing replicationwithin a standar design may not be satisfactory, The analysis of covariance has proven to be very effective
    alternative in many cases, after reducing de error variance by 25.50%. The data will probably include several observations collected over time on the same plant. The statistical analysis must take this into account, and several possible methods
    are suggested.

  1. Targeted genotyping-by-sequencing permits cost-effective identification and discrimination of pasture grass species and cultivars.

    Science.gov (United States)

    Pembleton, Luke W; Drayton, Michelle C; Bain, Melissa; Baillie, Rebecca C; Inch, Courtney; Spangenberg, German C; Wang, Junping; Forster, John W; Cogan, Noel O I

    2016-05-01

    A targeted amplicon-based genotyping-by-sequencing approach has permitted cost-effective and accurate discrimination between ryegrass species (perennial, Italian and inter-species hybrid), and identification of cultivars based on bulked samples. Perennial ryegrass and Italian ryegrass are the most important temperate forage species for global agriculture, and are represented in the commercial pasture seed market by numerous cultivars each composed of multiple highly heterozygous individuals. Previous studies have identified difficulties in the use of morphophysiological criteria to discriminate between these two closely related taxa. Recently, a highly multiplexed single nucleotide polymorphism (SNP)-based genotyping assay has been developed that permits accurate differentiation between both species and cultivars of ryegrasses at the genetic level. This assay has since been further developed into an amplicon-based genotyping-by-sequencing (GBS) approach implemented on a second-generation sequencing platform, allowing accelerated throughput and ca. sixfold reduction in cost. Using the GBS approach, 63 cultivars of perennial, Italian and interspecific hybrid ryegrasses, as well as intergeneric Festulolium hybrids, were genotyped. The genetic relationships between cultivars were interpreted in terms of known breeding histories and indistinct species boundaries within the Lolium genus, as well as suitability of current cultivar registration methodologies. An example of applicability to quality assurance and control (QA/QC) of seed purity is also described. Rapid, low-cost genotypic assays provide new opportunities for breeders to more fully explore genetic diversity within breeding programs, allowing the combination of novel unique genetic backgrounds. Such tools also offer the potential to more accurately define cultivar identities, allowing protection of varieties in the commercial market and supporting processes of cultivar accreditation and quality assurance.

  2. Evaluación agronómica y nutricional del pasto Ryegrass perenne tetraploide (Lolium perenne producido en lecherías de las zonas altas de Costa Rica. II. Valor nutricional

    Directory of Open Access Journals (Sweden)

    Luis Villalobos

    2010-01-01

    Full Text Available Se determinó el valor nutricional del pasto ryegrass perenne tetraploide (Lolium perenne en 4 fincas comerciales de ganado lechero ubicadas en Chicuá de Oreamuno (latitud 09°59', longitud 83°52', altitud 3090 msnm, provincia de Cartago. Las muestras se tomaron cada 2 meses a una altura de cosecha de 10 cm sobre el suelo, simulando el pastoreo que realizan los animales durante un período de un año. La composición nutricional promedio anual fue de 25,21% PC, 46,26% FDN, 25,57% FDA, 3,29% lignina, 15,40% CNF y 77,95% DIVMS y su contenido energético, expresado como TND, ED, EM, ENL (3X y ENG, fue 61,95%, 2,92, 2,45, 1,53 y 0,92 Mcal.kg-1 de MS, respectivamente. El valor nutricional del pasto ryegrass perenne varió (p¿0,05 según la época del año y el manejo en finca, especialmente en lo referente al período de recuperación de las pasturas. Este pasto tiene un contenido alto de PC y CNF, que permite a nivel ruminal la producción de proteína microbial, la cual es la mejor proteína que puede consumir un rumiante. En general, el valor nutricional del pasto Ryegrass perenne producido a altitudes superiores a los 2500 msnm en Costa Rica es similar, al producido en zonas de clima templado de donde es originario.

  3. Precipitation and runoff simulations of select perennial and ephemeral watersheds in the middle Carson River basin, Eagle, Dayton, and Churchill Valleys, west-central Nevada

    Science.gov (United States)

    Jeton, Anne E.; Maurer, Douglas K.

    2011-01-01

    The effect that land use may have on streamflow in the Carson River, and ultimately its impact on downstream users can be evaluated by simulating precipitation-runoff processes and estimating groundwater inflow in the middle Carson River in west-central Nevada. To address these concerns, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation, began a study in 2008 to evaluate groundwater flow in the Carson River basin extending from Eagle Valley to Churchill Valley, called the middle Carson River basin in this report. This report documents the development and calibration of 12 watershed models and presents model results and the estimated mean annual water budgets for the modeled watersheds. This part of the larger middle Carson River study will provide estimates of runoff tributary to the Carson River and the potential for groundwater inflow (defined here as that component of recharge derived from percolation of excess water from the soil zone to the groundwater reservoir). The model used for the study was the U.S. Geological Survey's Precipitation-Runoff Modeling System, a physically based, distributed-parameter model designed to simulate precipitation and snowmelt runoff as well as snowpack accumulation and snowmelt processes. Models were developed for 2 perennial watersheds in Eagle Valley having gaged daily mean runoff, Ash Canyon Creek and Clear Creek, and for 10 ephemeral watersheds in the Dayton Valley and Churchill Valley hydrologic areas. Model calibration was constrained by daily mean runoff for the 2 perennial watersheds and for the 10 ephemeral watersheds by limited indirect runoff estimates and by mean annual runoff estimates derived from empirical methods. The models were further constrained by limited climate data adjusted for altitude differences using annual precipitation volumes estimated in a previous study. The calibration periods were water years 1980-2007 for Ash Canyon Creek, and water years 1991-2007 for Clear Creek. To

  4. Effect of biochar on the presence of nutrients and ryegrass growth in the soil from an abandoned indigenous coking site: The potential role of biochar in the revegetation of contaminated site.

    Science.gov (United States)

    Zhang, Guixiang; Guo, Xiaofang; Zhu, Yuen; Han, Zhiwang; He, Qiusheng; Zhang, Fengsong

    2017-12-01

    Little is known regarding how biochars' feedstock and pyrolysis temperature affect soil function and plant growth. To address this gap in knowledge, 12 biochars (walnut shells, corn cobs, corn straws, and rice straws were separately pyrolyzed at 250, 400, and 600°C for 4h) were applied to soil from an indigenous coking site with application rate of 2.5% (w/w) in a pot experiment to determine the impact of biochar types on macro-nutrients (total and available N, P, and K) and ryegrass growth in the soil from an indigenous coking site. Generally, the total N, P, and K in the soil was not significantly different from that of the control group. However, biochars decreased the available N from 21.76mg·kg -1 for the control to 14.96mg·kg -1 . Corn straw and rice straw biochars increased the available P from 2.14mg·kg -1 for the control to 28.35mg·kg -1 , specifically at higher pyrolysis temperature, while walnut shell and corn cob biochars had little influence on it regardless of pyrolysis temperature. Biochars increased the available K from 173.58mg·kg -1 for the control to 355.64mg·kg -1 , varying as their feedstocks of corn cob>rice straw>corn straw>walnut shell and increasing with the increase of pyrolysis temperature. Correlation analysis suggests that it is responsible for the competition of soluble cations from biochars with K for adsorption sites on the soil surface. Biochars increased the ryegrass biomass from 0.07g·pot -1 for the control to 0.16g·pot -1 , with the generally most effective stimulation by biochars produced at 400°C. Ryegrass biomass had obviously positive correlation with available K, indicating its essential role in the growth of ryegrass in the studied soil. Copyright © 2017. Published by Elsevier B.V.

  5. Production of Enterocins L50A, L50B, and IT, a New Enterocin, by Enterococcus faecium IT62, a Strain Isolated from Italian Ryegrass in Japan▿

    Science.gov (United States)

    Izquierdo, Esther; Bednarczyk, Audrey; Schaeffer, Christine; Cai, Yimin; Marchioni, Eric; Van Dorsselaer, Alain; Ennahar, Saïd

    2008-01-01

    Enterococcus faecium IT62, isolated from ryegrass in Japan, was shown to produce three different bacteriocins, two of which had molecular masses and amino acid sequences that corresponded to those of enterocin L50A and enterocin L50B. These peptides existed, however, as chemically modified forms that were either N formylated or N formylated and oxidized at Met24. The third bacteriocin, named enterocin IT, had a molecular mass of 6,390 Da, was made up of 54 amino acids, and did not correspond to any known bacteriocin. However, enterocin IT was identical to the C-terminal part of the 16-amino-acid-longer bacteriocin 32 (T. Inoue, H. Tomita, and Y. Ike, Antimicrob. Agents Chemother., 50:1202-1212, 2006). For the first time, the antimicrobial activity spectra for enterocins L50A and L50B were determined separately and included a wide range of gram-positive bacteria but also a few gram-negative strains that were weakly sensitive. Slight differences in the activities of enterocins L50A and L50B were observed, as gram-positive bacteria showed an overall higher level of sensitivity to L50A than to L50B, as opposed to gram-negative ones. Conversely, enterocin IT showed a very narrow antimicrobial spectrum that was limited to E. faecium strains, one strain of Bacillus subtilis, and one strain of Lactococcus lactis. This study showed that E. faecium IT62, a grass-borne strain, produces bacteriocins with very different activity features and structures that may be found in strains associated with food or those of clinical origin, which demonstrates that a particular enterocin structure may be widespread and not related to the producer's origin. PMID:18391036

  6. Production of enterocins L50A, L50B, and IT, a new enterocin, by Enterococcus faecium IT62, a strain isolated from Italian ryegrass in Japan.

    Science.gov (United States)

    Izquierdo, Esther; Bednarczyk, Audrey; Schaeffer, Christine; Cai, Yimin; Marchioni, Eric; Van Dorsselaer, Alain; Ennahar, Saïd

    2008-06-01

    Enterococcus faecium IT62, isolated from ryegrass in Japan, was shown to produce three different bacteriocins, two of which had molecular masses and amino acid sequences that corresponded to those of enterocin L50A and enterocin L50B. These peptides existed, however, as chemically modified forms that were either N formylated or N formylated and oxidized at Met(24). The third bacteriocin, named enterocin IT, had a molecular mass of 6,390 Da, was made up of 54 amino acids, and did not correspond to any known bacteriocin. However, enterocin IT was identical to the C-terminal part of the 16-amino-acid-longer bacteriocin 32 (T. Inoue, H. Tomita, and Y. Ike, Antimicrob. Agents Chemother., 50:1202-1212, 2006). For the first time, the antimicrobial activity spectra for enterocins L50A and L50B were determined separately and included a wide range of gram-positive bacteria but also a few gram-negative strains that were weakly sensitive. Slight differences in the activities of enterocins L50A and L50B were observed, as gram-positive bacteria showed an overall higher level of sensitivity to L50A than to L50B, as opposed to gram-negative ones. Conversely, enterocin IT showed a very narrow antimicrobial spectrum that was limited to E. faecium strains, one strain of Bacillus subtilis, and one strain of Lactococcus lactis. This study showed that E. faecium IT62, a grass-borne strain, produces bacteriocins with very different activity features and structures that may be found in strains associated with food or those of clinical origin, which demonstrates that a particular enterocin structure may be widespread and not related to the producer's origin.

  7. Regulation of levels of serum antibodies to ryegrass pollen allergen Lol pIV by an internal image anti-idiotypic monoclonal antibody.

    Science.gov (United States)

    Zhou, E M; Kisil, F T

    1995-03-01

    A murine monoclonal anti-idiotypic antibody (anti-Id), designated B1/1, was produced against an idiotope of a murine antibody (mAb91), which recognizes the epitope, site A, of allergen Lol pIV, one of the major groups of allergens in ryegrass (Lolium perenne) pollen. The ability of B1/1 to modulate the antibody responses to Lol pIV was investigated in murine model systems. In the first system, B1/1-keyhole limpet haemocyanin (KLH) conjugate was administered to treat three different strains of mice (C57BL/6, BALB/c and C3H). In the second and third model systems, a solution of B1/1 in phosphate-buffered saline (PBS) was used to treat syngeneic BALB/c mice at various doses and time intervals, respectively. The treatment with either form of B1/1, administered at doses ranging from 100 ng to 100 micrograms mouse, resulted in a reduction of the levels of the antibodies to Lol pIV. In particular, the level of IgE antibodies to Lol pIV was greatly reduced. The administration of a single intravenous (i.v.) injection of a solution of B1/1 8 weeks prior to the challenge with Lol pIV was still effective in reducing the level of antibodies to the allergen. Moreover, the level of antibodies to Lol pIV that expressed the idiotope mAb91 was also markedly decreased. By contrast, it was observed that the level of antibodies to Lol pIV in mice pretreated with B1/1 in PBS at a dose of 10 ng/mouse increased (albeit slightly) compared to that in mice treated with control mAb. These experimental models lend themselves for investigating the mechanism(s) by which an anti-Id modulates antibody responses to a grass pollen allergen.

  8. Developing biosafety risk hypotheses for invertebrates exposed to GM plants using conceptual food webs: a case study with elevated triacylglyceride levels in ryegrass.

    Science.gov (United States)

    Barratt, Barbara I P; Todd, Jacqui H; Burgess, Elisabeth P J; Malone, Louise A

    2010-01-01

    Regulators are acutely aware of the need for meaningful risk assessments to support decisions on the safety of GM crops to non-target invertebrates in determining their suitability for field release. We describe a process for developing appropriate, testable risk hypotheses for invertebrates in agroecosystems that might be exposed to plants developed by GM and future novel technologies. An existing model (PRONTI) generates a ranked list of invertebrate species for biosafety testing by accessing a database of biological, ecological and food web information about species which occur in cropping environments and their potential interactions with a particular stressor (Eco Invertebase). Our objective in this contribution is to explore and further utilise these resources to assist in the process of problem formulation by identifying potentially significant effects of the stressor on the invertebrate community and the ecosystem services they provide. We propose that for high ranking species, a conceptual food web using information in Eco Invertebase is constructed, and using an accepted regulatory risk analysis framework, the likelihood of risk, and magnitude of impact for each link in the food web is evaluated. Using as filters only those risks evaluated as likely to extremely likely, and the magnitude of an effect being considered as moderate to massive, the most significant potential effects can be identified. A stepwise approach is suggested to develop a sequence of appropriate tests. The GM ryegrass plant used as the "stressor" in this study has been modified to increase triacylglyceride levels in foliage by 100% to increase the metabolisable energy content of forage for grazing animals. The high-ranking "test" species chosen to illustrate the concept are New Zealand native species Wiseana cervinata (Walker) (Lepidoptera: Hepialidae), Persectania aversa (Walker) (Lepidoptera: Noctuidae), and the self-introduced grey field slug, Deroceras reticulatum (Müller).

  9. Comparative assessment of the phytomeliorative efficiency of perennial grasses on chernozems in the transural part of Bashkortostan

    Science.gov (United States)

    Khasanova, R. F.; Suyundukov, Ya. T.; Suyundukova, M. B.

    2010-01-01

    The phytomeliorative efficiency of different groups of perennial herbs was studied. The agrophysical properties of soils under natural grasses (the feather grasses Stipa pennata, S. zalesskii, and S. Lessingiana; the fescue grass Festuca pseudovina; and quack grass), sawn herbs (awnless brome, crested wheat grass, purple alfalfa, the holy clover Onobrychis sibirica, the galega Galega orientalis, and yellow sweet clover), and cereal crops (winter rye and spring wheat) were compared. The formation of the aboveground and underground phytomass and the influence of phytomeliorative herbs on the aggregate state of leached, ordinary, and southern chernozems in the Transural part of Bashkortostan were analyzed.

  10. Performance, Economics and Potential Impact of Perennial Rice PR23 Relative to Annual Rice Cultivars at Multiple Locations in Yunnan Province of China

    Directory of Open Access Journals (Sweden)

    Guangfu Huang

    2018-04-01

    Full Text Available Perennial grain crops hold the promise of stabilizing fragile lands, while contributing grain and grazing in mixed farming systems. Recently, perennial rice was reported to successfully survive, regrow, and yield across a diverse range of environments in Southern China and Laos, with perennial rice PR23 being identified as a prime candidate for release to farmers. This paper reports the evaluation of PR23 for release, by (1 comparing its survival, regrowth, performance, and adaptation with preferred annual rices across nine ecological regions in southern Yunnan Province of China; (2 examining the economic costs and benefits of perennial versus annual rice there; and (3 discussing the evidence for the release of PR23 as a broadly adapted and acceptable cultivar for farmers. Overall, the grain yield of PR23 was similar to those of the preferred annual rice cultivars RD23 and HXR7, but the economic analysis indicated substantial labour savings for farmers by growing the perennial instead of the annual. PR23 was comparable to the annuals in phenology, plant height, grain yield, and grain size, and was acceptable in grain and cooking quality. Farmers were keen to grow it because of reduced costs and especially savings in labour. PR23 is proposed for release to farmers because of its comparable grain yields to annual rices, its acceptable grain and milling quality, its cost and labour savings, and the likely benefits to soil stability and ecological sustainability, along with more flexible farming systems.

  11. Pyrolysis and kinetic analyses of a perennial grass (Saccharum ravannae L.) from north-east India: Optimization through response surface methodology and product characterization.

    Science.gov (United States)

    Saikia, Ruprekha; Baruah, Bhargav; Kalita, Dipankar; Pant, Kamal K; Gogoi, Nirmali; Kataki, Rupam

    2018-04-01

    The objective of the present investigation was to optimize the pyrolysis condition of an abundantly available and low cost perennial grass of north-east India Saccharum ravannae L. (S. ravannae) using response surface methodology based on central composite design. Kinetic study of the biomass was conducted at four different heating rates of 10, 20, 40 and 60 °C min -1 and results were interpreted by Friedman, Kissinger Akira Sunnose and Flynn-Wall-Ozawa methods. Average activation energy 151.45 kJ mol -1 was used for evaluation of reaction mechanism following Criado master plot. Maximum bio-oil yield of 38.1 wt% was obtained at pyrolysis temperature of 550 °C, heating rate of 20 °C min -1 and nitrogen flow rate of 226 mL min -1 . Study on bio-oil quality revealed higher content of hydrocarbon, antioxidant property, total phenolic content and metal chelating capacity. These opened up probable applications of S. ravannae bio-oil in different fields including fuel, food industry and biomedical domain. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Prospects for Hybrid Breeding in Bioenergy Grasses

    DEFF Research Database (Denmark)

    Aguirre, Andrea Arias; Studer, Bruno; Frei, Ursula

    2012-01-01

    , we address crucial topics to implement hybrid breeding, such as the availability and development of heterotic groups, as well as biological mechanisms for hybridization control such as self-incompatibility (SI) and male sterility (MS). Finally, we present potential hybrid breeding schemes based on SI...... of different hybrid breeding schemes to optimally exploit heterosis for biomass yield in perennial ryegrass (Lolium perenne L.) and switchgrass (Panicum virgatum), two perennial model grass species for bioenergy production. Starting with a careful evaluation of current population and synthetic breeding methods...

  13. Trophic strategy of Atlantirivulus riograndensis (Cyprinodontiformes: Rivulidae, a non-annual rivulid threatened by extinction, in a perennial environment, Brazil

    Directory of Open Access Journals (Sweden)

    Laísa Wociechoski Cavalheiro

    Full Text Available ABSTRACT Rivulidae includes non-annual fish of perennial habitats and annual fish of temporary wetlands. The objective of this research was to investigate the trophic strategy of Atlantirivulus riograndensis in a perennial environment. Sampling occurred in an environmental conservation unit in the Pampa biome, Brazil. Quantification of the diet followed the volumetric method. Consumption of autochthonous material as the main food source of the species followed the pattern of Rivulidae. Species is zooplanktonic when young. Food spectrum is broadened and insectivorousness increases with ontogeny, revealing a specialist trend in the feeding strategy of A. riograndensis. The most diverse feeding occurs in the spring and summer seasons in which the presence of larger fish was more frequent than in other seasons. The increased consumption of microcrustaceans in the fall was related to smaller individuals, captured in greater quantities in this post-reproductive period. The lowest diversity of dietary items occurs during the winter and may reflect the lower diversity of food resources available in this season or the transition from juvenile to adult diet, with consumption of autochthonous Diptera by medium sized fish.

  14. Acclimation of bloom-forming and perennial seaweeds to elevated pCO2 conserved across levels of environmental complexity.

    Science.gov (United States)

    Xu, Dong; Schaum, Charlotte-Elisa; Lin, Fan; Sun, Ke; Munroe, James R; Zhang, Xiao W; Fan, Xiao; Teng, Lin H; Wang, Yi T; Zhuang, Zhi M; Ye, Naihao

    2017-11-01

    Macroalgae contribute approximately 15% of the primary productivity in coastal marine ecosystems, fix up to 27.4 Tg of carbon per year, and provide important structural components for life in coastal waters. Despite this ecological and commercial importance, direct measurements and comparisons of the short-term responses to elevated pCO 2 in seaweeds with different life-history strategies are scarce. Here, we cultured several seaweed species (bloom forming/nonbloom forming/perennial/annual) in the laboratory, in tanks in an indoor mesocosm facility, and in coastal mesocosms under pCO 2 levels ranging from 400 to 2,000 μatm. We find that, across all scales of the experimental setup, ephemeral species of the genus Ulva increase their photosynthesis and growth rates in response to elevated pCO 2 the most, whereas longer-lived perennial species show a smaller increase or a decrease. These differences in short-term growth and photosynthesis rates are likely to give bloom-forming green seaweeds a competitive advantage in mixed communities, and our results thus suggest that coastal seaweed assemblages in eutrophic waters may undergo an initial shift toward communities dominated by bloom-forming, short-lived seaweeds. © 2017 John Wiley & Sons Ltd.

  15. Reproductive effort of some annual and perennial plant species: impact of successional sequence, habitat conditions and plant size

    International Nuclear Information System (INIS)

    Shaukat, S.; Khan, M.A.; Zaidi, S.; Siddiqui, M.F.; Khan, N.; Zafar, H.

    2013-01-01

    The reproductive effort of some annual and perennial plant species was investigated with respect to successional sequence, habitat conditions and plant size. in the psammosere succession (dune succession), the reproductive effort (RE) of Cressa cretica and A triplex griffithii was significantly greater in the early stage compared to that in late succession. Likewise, in relation to lithosere succession, Sporobolus arabicus. Pluchea lanceolata and Vernonia cenerescens all showed high reproductive effort in early part of succession compared to that of late succession. The annuals (S. arabicus and P lance/ala) exhibited greater reproductive effort compared to the perennial species Vernonia cinerescens. Examination of the Impact of site differences on reproductive effort showed that four grasses including Selaria intermedia, Chioris harbata, Cenchrus hiflorus, and Eragroslis pilosa were found to have significantly (P<0.05) greater reproductive effort in site 1 (near cultivated field), compared to site 2 (a vacant lot), which had low nutrient level compared to site 1. The reproductive effort of Sonclius asper (a composite) did not exhibit significant difference between sites. The investigation of relationships between plant size (volume) and reproductive effort of Solanuin forskalii, Senna holosericea and Heliolropium ophioglossum showed positive correlations between plant size and reproductive effort. Solanum forskalii and Senna holosericca, in particular, exhibited a close association in this respect. It is concluded that: 1) RE is greater in early compared to late succession, 2) RE changes with the habitat and 3) there seems to be a direct relationship between RE and plant size. (author)

  16. Expression of alkane monooxygenase (alkB) genes by plant-associated bacteria in the rhizosphere and endosphere of Italian ryegrass (Lolium multiflorum L.) grown in diesel contaminated soil

    International Nuclear Information System (INIS)

    Andria, Verania; Reichenauer, Thomas G.; Sessitsch, Angela

    2009-01-01

    For phytoremediation of organic contaminants, plants have to host an efficiently degrading microflora. To assess the role of endophytes in alkane degradation, Italian ryegrass was grown in sterile soil with 0, 1 or 2% diesel and inoculated either with an alkane degrading bacterial strain originally derived from the rhizosphere of Italian ryegrass or with an endophyte. We studied plant colonization of these strains as well as the abundance and expression of alkane monooxygenase (alkB) genes in the rhizosphere, shoot and root interior. Results showed that the endophyte strain better colonized the plant, particularly the plant interior, and also showed higher expression of alkB genes suggesting a more efficient degradation of the pollutant. Furthermore, plants inoculated with the endophyte were better able to grow in the presence of diesel. The rhizosphere strain colonized primarily the rhizosphere and showed low alkB gene expression in the plant interior. - Bacterial alkane degradation genes are expressed in the rhizosphere and in the plant interior.

  17. Expression of alkane monooxygenase (alkB) genes by plant-associated bacteria in the rhizosphere and endosphere of Italian ryegrass (Lolium multiflorum L.) grown in diesel contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Andria, Verania [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria); Reichenauer, Thomas G. [AIT Austrian Institute of Technology GmbH, Unit of Environmental Resources and Technologies, A-2444 Seibersdorf (Austria); Sessitsch, Angela, E-mail: angela.sessitsch@ait.ac.a [AIT Austrian Institute of Technology GmbH, Bioresources Unit, A-2444 Seibersdorf (Austria)

    2009-12-15

    For phytoremediation of organic contaminants, plants have to host an efficiently degrading microflora. To assess the role of endophytes in alkane degradation, Italian ryegrass was grown in sterile soil with 0, 1 or 2% diesel and inoculated either with an alkane degrading bacterial strain originally derived from the rhizosphere of Italian ryegrass or with an endophyte. We studied plant colonization of these strains as well as the abundance and expression of alkane monooxygenase (alkB) genes in the rhizosphere, shoot and root interior. Results showed that the endophyte strain better colonized the plant, particularly the plant interior, and also showed higher expression of alkB genes suggesting a more efficient degradation of the pollutant. Furthermore, plants inoculated with the endophyte were better able to grow in the presence of diesel. The rhizosphere strain colonized primarily the rhizosphere and showed low alkB gene expression in the plant interior. - Bacterial alkane degradation genes are expressed in the rhizosphere and in the plant interior.

  18. Desempenho de cordeiras em pastagens de azevém e de milheto sob suplementação Performance of female lambs on Italian ryegrass and pearl millet pastures under supplement levels

    Directory of Open Access Journals (Sweden)

    Denise Adelaide Gomes Elejalde

    2010-04-01

    Full Text Available Avaliou-se o desempenho de cordeiras em pastagens de azevém (Lolium multiflorum Lam. e de milheto (Pennisetum americanum L. Leeke como alimento exclusivo ou com suplementação diária com ração comercial na proporção de 0,5; 1,0 e 1,5% do peso corporal (PC. O método de pastejo utilizado foi o de lotação contínua com taxa de lotação variável. As cordeiras em pastagem de azevém com suplementação nos níveis de 0,5 e 1,5% do PC apresentaram maior ganho médio diário. Independentemente do nível, a suplementação em pastagem de azevém promoveu o maior ganho de peso por área. Na pastagem de milheto, o ganho médio diário, o ganho de peso por área e o escore de condição corporal foram maiores nas cordeiras sob suplementação. A estrutura de pastagens de azevém e de milheto não é influenciada pela oferta de suplemento aos animais. A utilização da pastagem de azevém nos períodos pré e pós-desmama, associada à suplementação nos níveis de 0,5 a 1,5% do peso vivo em pastagem de milheto, permite que cordeiras apresentem peso e escore de condição corporal adequados para o acasalamento aos 9 meses de idade.It was evaluated the performance of female lambs on cultivated pastures of Italian ryegrass (Lolium multiflorum Lam. and pearl millet (Pennisetum americanum (L. Leeke as exclusive food or as daily supplementation with commercial feed at the ratio of 0.5, 1.0 and 1.5% of the body weight. The used grazing method was continuous with variable stocking. Female lambs on Italian ryegrass pasture supplemented with 0.5 and 1.5% of body weight presented greater average daily gain. Regardless to the level, supplementation on Italian ryegrass pasture promoted the highest weight gain per area. In pearl millet pasture, the daily weight gain, the weight gain per area and body condition score were higher for the lambs under supplementation. The structure of Italian ryegrass and pearl millet pastures is not affected by the offer of

  19. Effects of dairy manure management in annual and perennial cropping systems on soil microbial communities associated with in situ N2O fluxes

    Science.gov (United States)

    Dunfield, Kari; Thompson, Karen; Bent, Elizabeth; Abalos, Diego; Wagner-Riddle, Claudia

    2016-04-01

    Liquid dairy manure (LDM) application and ploughing events may affect soil microbial community functioning differently between perennial and annual cropping systems due to plant-specific characteristics stimulating changes in microbial community structure. Understanding how these microbial communities change in response to varied management, and how these changes relate to in situ N2O fluxes may allow the creation of predictive models for use in the development of best management practices (BMPs) to decrease nitrogen (N) losses through choice of crop, plough, and LDM practices. Our objectives were to contrast changes in the population sizes and community structures of genes associated with nitrifier (amoA, crenamoA) and denitrifier (nirK, nirS, nosZ) communities in differently managed annual and perennial fields demonstrating variation in N2O flux, and to determine if differences in these microbial communities were linked to the observed variation in N2O fluxes. Soil was sampled in 2012 and in 2014 in a 4-ha spring-applied LDM grass-legume (perennial) plot and two 4-ha corn (annual) treatments under fall or spring LDM application. Soil DNA was extracted and used to target N-cycling genes via qPCR (n=6) and for next-generation sequencing (Illumina Miseq) (n=3). Significantly higher field-scale N2O fluxes were observed in the annual plots compared to the perennial system; however N2O fluxes increased after plough down of the perennial plot. Nonmetric multidimensional scaling (NMS) indicated differences in N-cycling communities between annual and perennial cropping systems, and some communities became similar between annual and perennial plots after ploughing. Shifts in these communities demonstrated relationships with agricultural management, which were associated with differences in N2O flux. Indicator species analysis was used to identify operational taxonomic units (OTUs) most responsible for community shifts related to management. Nitrifying and denitrifying soil

  20. Medicinal Flowers. XXXII. Structures of oleanane-type triterpene saponins, perennisosides VIII, IX, X, XI, and XII, from the flowers of Bellis perennis.

    Science.gov (United States)

    Morikawa, Toshio; Li, Xuezheng; Nishida, Eriko; Nakamura, Seikou; Ninomiya, Kiyofumi; Matsuda, Hisashi; Hamao, Makoto; Muraoka, Osamu; Hayakawa, Takao; Yoshikawa, Masayuki

    2011-01-01

    Five new triterpene saponins perennisosides VIII (1), IX (2), X (3), XI (4), and XII (5) were isolated from the MeOH-eluated fraction of the methanolic extract from the flowers of Bellis perennis. The MeOH-eluted fraction of the methanolic extract from the flowers of B. perennis was found to inhibit gastric emptying in olive oil-loaded mice at a dose of 200 mg/kg, per os (p.o.). The stereostructures of 1-5 were elucidated on the basis of chemical and spectroscopic evidence.

  1. Anticholinesterase activity and chemical profile of an active chromatographic fraction of ethanolic extract from Bellis perennis L. (Asteraceae) flowers; Atividade anticolinesterasica e perfil quimico de uma fracao cromatografica ativa do extrato etanolico das flores Bellis perennis L. (Asteraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Thiago Henrique Costa; Santos, Pauline Sousa dos; Freitas, Rivelilson Mendes de, E-mail: rivelilson@pq.cnpq.br [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Centro de Ciencias da Saude. Departamento de Bioquimica e Farmacologia; Carvalho, Rusbene Bruno Fonseca de; Melo, Cassio Herbert Santos de [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Centro de Ciencias da Natureza. Departamento de Quimica; David, Juceni Pereira [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Faculdade de Farmacia; David, Jorge Mauricio; Lima, Luciano Silva [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica

    2013-09-01

    This work describes the isolation of an active flavonoid fraction and identification of isorhamnetin 3-O-{beta}-D-(6''-acetyl)- alactopyranoside from flowers of B. perennis, and also the evaluation of anticholinesterase (AChE) activity of ethanolic extract from flowers (EEF) and the active fraction. The chemical structure of the flavonoid was defined on the basis of spectroscopic {sup 1}H NMR, IR and UV data. EEF or flavonoid reduces AChE activity in vivo, while flavonoid also reduces AChE activity in vitro, showing a value of 1.49 {mu}M for 50% inhibitory concentration (IC{sub 50}), suggesting potential use as an insecticide or in the treatment of neurodegenerative diseases such as Alzheimer's disease. (author)

  2. Comparative performance of annual and perennial energy cropping systems under different management regimes

    Energy Technology Data Exchange (ETDEWEB)

    Boehmel, Ute Constanze

    2007-07-18

    The theme of this thesis was chosen against the background of the necessary substitution of fossil fuels and the need to reduce greenhouse gas emissions. One major solution for these topics may be the energy generation from domestically produced biomass. The overall aim of this thesis was the identification of one or more efficient energy cropping systems for Central Europe. The existence of diverse production environments necessitates further diversification and the identification of several energy crops and the development of energy cropping systems suited to those diverse environments. This thesis starts with an introductory essay (chapter 1), which provides the background for renewable energy production, its features, demands and potentials, and the scientific basis of this thesis. Chapters 2 to 6 consist of five manuscripts to be published in reviewed journals (Papers I, II, IV and V) or in a multi-author book (Paper III). Subsequently, the results from all papers are discussed in a general setting (chapter 7), from which a general conclusion is formulated (chapter 8). The basis of the research formed four field experiments, which were conducted at the experimental sites Ihinger Hof, Oberer Lindenhof and Goldener Acker of the University of Hohenheim, in south-western Germany. Paper I addresses the overall objective of this thesis. Selected cropping systems for this experiment were short rotation willow, miscanthus, switchgrass, energy maize and two different crop rotation systems including winter oilseed rape, winter wheat and winter triticale with either conventional tillage or no-till. The systems were cultivated with three different nitrogen fertilizer applications. An energy balance was calculated to evaluate the biomass and energy yields of the different cropping systems. Results indicate that perennial lignocellulosic crops combine high biomass and net energy yields with low input and potential ecological impacts. Switchgrass, which produced low yields

  3. Productivity and carbon footprint of perennial grass-forage legume intercropping strategies with high or low nitrogen fertilizer input

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Lachouani, Petra; Knudsen, Marie Trydeman

    2016-01-01

    with either a high or a low rate of mineral nitrogen (N) fertilizer. Life cycle assessment (LCA) was used to evaluate the carbon footprint (global warming potential) of the grassland management including measured nitrous oxide (N2O) emissions after sward incorporation. Without applying any mineral N......A three-season field experiment was established and repeated twice with spring barley used as cover crop for different perennial grass-legume intercrops followed by a full year pasture cropping and winter wheat after sward incorporation. Two fertilization regimes were applied with plots fertilized...... carbon footprint. Thus, a reduction in N fertilizer application rates in the low input systems offsets increased N2O emissions after forage legume treatments compared to grass plots due to the N fertilizer production-related emissions. When including the subsequent wheat yield in the total aboveground...

  4. Anticholinesterase activity and chemical profile of an active chromatographic fraction of ethanolic extract from Bellis perennis L. (Asteraceae) flowers

    International Nuclear Information System (INIS)

    Marques, Thiago Henrique Costa; Santos, Pauline Sousa dos; Freitas, Rivelilson Mendes de; Carvalho, Rusbene Bruno Fonseca de; Melo, Cassio Herbert Santos de; David, Juceni Pereira; David, Jorge Mauricio; Lima, Luciano Silva

    2013-01-01

    This work describes the isolation of an active flavonoid fraction and identification of isorhamnetin 3-O-β-D-(6’’-acetyl)- alactopyranoside from flowers of B. perennis, and also the evaluation of anticholinesterase (AChE) activity of ethanolic extract from flowers (EEF) and the active fraction. The chemical structure of the flavonoid was defined on the basis of spectroscopic 1 H NMR, IR and UV data. EEF or flavonoid reduces AChE activity in vivo, while flavonoid also reduces AChE activity in vitro, showing a value of 1.49 μM for 50% inhibitory concentration (IC 50 ), suggesting potential use as an insecticide or in the treatment of neurodegenerative diseases such as Alzheimer’s disease. (author)

  5. Multi-farm economic analysis of perennial energy crops in Central Greece, taking into account the CAP reform

    International Nuclear Information System (INIS)

    Lychnaras, Vassilis; Schneider, Uwe A.

    2011-01-01

    This study analyses farm level economic impacts of biomass production from perennial crops including Arundo donax L. (arundo), Miscanthus x giganteus (miscanthus), Panicum virgatum L. (switchgrass) and Cynara cardunculus L. (cardoon). Regional biomass supply curves are estimated with a dynamic, multi-farm, mathematical programming model. Micro-economic data for the model are generated from farm surveys covering 52 farms containing a total of 400 parcels, in Central Greece. The study also examines the potential effects of the Common Agricultural Policy reform in 2003 on regional biomass supply. Simulations show that the policy reform toward decoupled subsidies lowers the cost of biomass between 15 and 25 euro per tonne. Switchgrass appears to be the most attractive option, followed by cardoon and miscanthus. Due to high specific machinery cost, arundo is never preferred. Relative to the agricultural policy setting of Agenda 2000, the biomass potential increases more for farms of small economic size and farms with a higher share of cotton. (author)

  6. Multi-farm economic analysis of perennial energy crops in Central Greece, taking into account the CAP reform

    Energy Technology Data Exchange (ETDEWEB)

    Lychnaras, Vassilis [Centre for Planning and Economic Research, 11, Amerikis str., 106 72 Athens (Greece); Schneider, Uwe A. [Research Unit Sustainability and Global Change, University of Hamburg, KlimaCampus Hamburg, Bundesstrasse 55, D-20146 Hamburg (Germany)

    2011-01-15

    This study analyses farm level economic impacts of biomass production from perennial crops including Arundo donax L. (arundo), Miscanthus x giganteus (miscanthus), Panicum virgatum L. (switchgrass) and Cynara cardunculus L. (cardoon). Regional biomass supply curves are estimated with a dynamic, multi-farm, mathematical programming model. Micro-economic data for the model are generated from farm surveys covering 52 farms containing a total of 400 parcels, in Central Greece. The study also examines the potential effects of the Common Agricultural Policy reform in 2003 on regional biomass supply. Simulations show that the policy reform toward decoupled subsidies lowers the cost of biomass between 15 and 25 euro per tonne. Switchgrass appears to be the most attractive option, followed by cardoon and miscanthus. Due to high specific machinery cost, arundo is never preferred. Relative to the agricultural policy setting of Agenda 2000, the biomass potential increases more for farms of small economic size and farms with a higher share of cotton. (author)

  7. Very low level radioactive wastes. Must the doctrine evolve? Reflections by the IRSN for a perennial, fair and liable management

    International Nuclear Information System (INIS)

    2016-01-01

    As large programmes of dismantling of nuclear installations are to be elaborated and implemented during the next decades, it appears the Cires (industrial centre for gathering, warehousing and storage), the single solution for very low level radioactive wastes in France, will be saturated on the short term. Therefore, this report aims at reviewing the present policy of waste management in order to make it more perennial, fairer and more liable. First, it identifies strengths and weaknesses of the present doctrine. It examines the kind of governance necessary to decide how this doctrine should evolve, by taking societal stakes, and debate places and modalities into account. While referring to technological options, it examines the possible orientations for an evolution of management modalities: material valorisation, diversification of storage options, and limitation of waste production

  8. The Perennial Environment Observatory by A.N.D.R.A. (the French National Radioactive Waste Management Agency)

    International Nuclear Information System (INIS)

    Leclerc, E.

    2010-01-01

    The Perennial Environment Observatory [Observatoire Perenne de l'Environnement - OPE] is a unique approach and infrastructure developed and implemented by ANDRA, the French National Radioactive Waste Management Agency, as part of its overall project of deep geological disposal for radioactive waste. Its current mission is to assess the initial state of the rural (forest, pasture, open-field and aquatic) environment, prior to repository construction. This will be followed in 2017 (pending construction authorizations) and for a period exceeding a century, by monitoring of any impact the repository may have on the environment. In addition to serving its own industrial purpose of environmental monitoring, ANDRA also opens the OPE approach, infrastructure and acquired knowledge (database...) to the scientific community to support further research on long term evolution of the environment subjected to natural and anthropogenic stresses, and to contribute to a better understanding of the interaction between the various compartments of the environment. (author)

  9. Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion.

    Science.gov (United States)

    Zhou, Xiaobo; Helmers, Matthew J; Asbjornsen, Heidi; Kolka, Randy; Tomer, Mark D

    2010-01-01

    Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (PFS) to mitigate increases in NO3-N levels. The study, conducted at the Neal Smith National Wildlife Refuge (NSNWR) in central Iowa, consisted of a balanced incomplete block design with 12 watersheds and four watershed-scale treatments having different proportions and topographic positions of PFS planted in native prairie grasses: 100% rowcrop, 10% PFS (toeslope position), 10% PFS (distributed on toe and as contour strips), and 20 PFS (distributed on toe and as contour strips). All treatments were established in fall 2006 on watersheds that were under bromegrass (Bromus L.) cover for at least 10 yr. Nonperennial areas were maintained under a no-till 2-yr corn (Zea mays L.)--soybean [Glycine max. (L.) Merr.] rotation since spring 2007. Suction lysimeter and shallow groundwater wells located at upslope and toeslope positions were sampled monthly during the growing season to determine NO3-N concentration from 2005 to 2008. The results indicated significant increases in NO3-N concentration in soil and groundwater following grassland-to-cropland conversion. Nitrate-nitrogen levels in the vadose zone and groundwater under PFS were lower compared with 100% cropland, with the most significant differences occurring at the toeslope position. During the years following conversion, PFS mitigated increases in subsurface nitrate, but long-term monitoring is needed to observe and understand the full response to land-use conversion.

  10. Consequences of buffelgrass pasture development for primary productivity, perennial plant richness, and vegetation structure in the drylands of Sonora, Mexico.

    Science.gov (United States)

    Franklin, Kimberly; Molina-Freaner, Francisco

    2010-12-01

    In large parts of northern Mexico native plant communities are being converted to non-native buffelgrass (Pennisetum ciliare) pastures, and this conversion could fundamentally alter primary productivity and species richness. In Sonora, Mexico land conversion is occurring at a regional scale along a rainfall-driven gradient of primary productivity, across which native plant communities transition from desert scrub to thorn scrub. We used a paired sampling design to compare a satellite-derived index of primary productivity, richness of perennial plant species, and canopy-height profiles of native plant communities with buffelgrass pastures. We sampled species richness across a gradient of primary productivity in desert scrub and thorn scrub vegetation to examine the influence of site productivity on the outcomes of land conversion. We also examined the influence of pasture age on species richness of perennial plants. Index values of primary productivity were lower in buffelgrass pastures than in native vegetation, which suggests a reduction in primary productivity. Land conversion reduced species richness by approximately 50% at local and regional scales, reduced tree and shrub cover by 78%, and reduced canopy height. Land conversion disproportionately reduced shrub species richness, which reflects the common practice among Sonoran ranchers of conserving certain tree and cactus species. Site productivity did not affect the outcomes of land conversion. The age of a buffelgrass pasture was unrelated to species richness within the pasture, which suggests that passive recovery of species richness to preconversion levels is unlikely. Our findings demonstrate that land conversion can result in large losses of plant species richness at local and regional scales and in substantial changes to primary productivity and vegetation structure, which casts doubt on the feasibility of restoring native plant communities without active intervention on the part of land managers.

  11. Genes and quantitative trait loci (QTL) controlling trace element concentrations in perennial grasses grown on phytotoxic soil contaminated with heavy metals

    Science.gov (United States)

    Perennial grasses cover diverse soils throughout the world, including sites contaminated with heavy metals, producing forages that must be safe for livestock and wildlife. Chromosome regions known as quantitative trait loci (QTLs) controlling forage mineral concentrations were mapped in a populatio...

  12. Foliar glyphosate treatment alters transcript and hormone profiles in crown buds of leafy spurge and induces dwarfed and bushy phenotypes throughout its perennial life cycle

    Science.gov (United States)

    Leafy spurge (Euphorbia esula) is an invasive weed of North America and its perennial nature is attributed to underground adventitious buds (UABs) that undergo seasonal cycles of para-, endo- and eco-dormancy. Recommended field rates of glyphosate (~1 kg/ha) destroys above-ground shoots of leafy spu...

  13. Effect of harvest timing on leaf production and yield of diterpene glycosides in Stevia rebaudiana Bert: a specialty perennial crop for Mississippi

    Science.gov (United States)

    Stevia rebaundiana (Bertoni), a perennial shrub of the Asteraceae, is one of the most important sources of non-caloric natural sweeteners. Stevia’s plant extracts and glycosides have been used for several years in Paraguay and Brazil. Several studies suggest that Stevia and its glycosides exert ben...

  14. Evaulation of perennial pepperweed (Lepidium latifolium) management in a seasonal wetland in San Francisco Estuary prior to restoration of tidal hydrology

    Science.gov (United States)

    Herbicide applications have shown potential for control and management of invasive perennial pepperweed (Lepidium latifolium) in rangelands and tidal wetlands. However, reported efficacy of management methods varies widely, and the effects of more recently labeled aquatic herbicides on non-target ve...

  15. Strip cropping of alternating perennial grass–clover and annual rye–vetch intercrops when grown within an organic farming system

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, Henrik; Johansen, A.; Carter, Mette Sustmann

    2012-01-01

    interactions. Less soil water content below the perennial strip indicated greater water uptake, than below the annual strips. Unfortunately, the present strip cropping system did not possess the right balance of co-existence and complementarity. However, from a practical point of view the system was manageable...

  16. Efficacy of permethrin-treated bed nets in the prevention of mortality in young children in an area of high perennial malaria transmission in western Kenya

    NARCIS (Netherlands)

    Phillips-Howard, Penelope A.; Nahlen, Bernard L.; Kolczak, Margarette S.; Hightower, Allen W.; ter Kuile, Feiko O.; Alaii, Jane A.; Gimnig, John E.; Arudo, John; Vulule, John M.; Odhacha, Amos; Kachur, S. Patrick; Schoute, Erik; Rosen, Daniel H.; Sexton, John D.; Oloo, Aggrey J.; Hawley, William A.

    2003-01-01

    A group-randomized controlled trial of insecticide (permethrin)-treated bed nets (ITNs) was conducted in an area of high perennial malaria transmission in western Kenya to test the effect of ITNs on all-cause mortality in children 1-59 months of age. Child deaths were monitored over a two-year

  17. Evaluation of Seed and Forage Yield of Perennial Plants with Low Water Requirement in Abandoned Farming Lands

    Directory of Open Access Journals (Sweden)

    Ali gazanchian

    2017-10-01

    Full Text Available Introduction Drought is a natural phenomenon in arid and semi-arid regions of the world. It is created by low precipitation, high evaporation and reduced soil moisture. Today, they are the major threats to agricultural lands due to fluctuations in rainfall, limited water resources, wells salinization and subsequently abandoned farming lands. Iran is located on the world's dry belt and more than 90 percent of its area is located in the arid and semi-arid climatic regions. It has been reported that the annual rate of soil erosion is up to 33 tons per hectare and 5 to 6 times more than the standard limit. Also, 90% of the country's protein production comes from animals sources. Due to the lack of adequate forage production, the main burden of protein production is imposed on the natural resources and pastures. Therefore, In order to enhance soil stabilization and maintain its fertility, optimum use of off-season precipitations, preventing the flow of water and protecting the abandoned farming lands from the flood risk, increasing the water permeability in the soil, and helping to feed the underwater aquifers and finally the production of forage and seeds, the development of perennial plants cultivation is an important conservative practice. The aim of this study is to emphasize on the selection of the best perennial forage species with low water requirements and acceptable performance for renovation of the abandoned farming lands and moving towards sustainable agriculture approaches. Materials and Methods In this experiment, 10 species of perennial grasses (Agropyron elongatum Host., Secale montanum Guss., Festuca arundinaceae Schreb., Dactylis glomerata L., Agropyron intermedium Host., Agropyron repense L., Agropyron cristatum L., Panicum antidutale Retz., Bromus inermis Leyss., Bromus riparius Rehmann, Agropyron cristatum L. and two legumes includes Trifolium pratense L., Onobrychis sativa Lam. were studied at Asatan-e-Ghods Razavi farm in

  18. Produção e qualidade de forragem da mistura de aveia e azevém sob dois métodos de estabelecimento Forage production and quality of oats and ryegrass mixture under two establishment methods

    Directory of Open Access Journals (Sweden)

    Marta Gomes da Rocha

    2007-02-01

    Full Text Available Neste trabalho, comparou-se a sobre-semeadura de aveia (Avena strigosa Schreb. e azevém (Lolium multiflorum Lam. em pastagem de coastcross (Cynodon dactylon (L. Pers. ao cultivo estreme como métodos de implantação de pastagens de inverno em sistema de pastejo rotacionado com vacas holandesas em lactação. Foram avaliados a produção total de MS (PTF, a massa de forragem de entrada (MFE, o resíduo (RES, as perdas de forragem (PD, a taxa de acúmulo diário de MS (TAD, a carga animal (CA, a oferta de forragem (OF e a biomassa de lâminas foliares (BLF. Para determinação da composição botânica, foram separados em cada espécie (aveia, azevém e coastcross os componentes estruturais folha, colmo e material senescente. Na entrada e saída dos animais da pastagem, foram colhidas amostras por simulação de pastejo para determinação dos teores de PB e FDN. Não houve diferença entre tratamentos para PTF, MFE, RES, PD, TAD, OF e CA. A oferta média de lâminas foliares foi de 1,3±0,67 kg LF/100 kg PV. A sobre-semeadura proporcionou maior biomassa de lâminas foliares disponibilizando forragem com maior teor de PB e menor de FDN na entrada e saída dos animais da pastagem.The oats (Avena strigosa Schreb. and ryegrass (Lolium multiflorum Lam. sodseeding in pasture of coastcross (Cynodon dactylon (L. Pers. was compared to oats and ryegrass in extreme tillage, as establishment methods of winter pastures under rotational stocking with lactating Holstein dairy cows. The total DM production (DMP, pre-grazed herbage mass, residue (RES, forage losses (FL, daily DM accumulation rate (DAR, stocking rate (SR, forage on offer (FO and leaf blade biomass (LBB were evaluated. For botanical composition, oats, ryegrass and coastcross were separated in the structural components: leaves, stems and dead material. Hand plucking samples for CP and NDF determinations were collected during pre- and post-grazing. The DMP, HM, RES, FL, DAR, SR and FO were not

  19. Abiotic factors affect the recruitment and biomass of perennial grass and evergreen shrub seedlings in denuded areas of Patagonian Monte rangelands.

    Science.gov (United States)

    Bosco, Tomás; Bertiller, Mónica Beatriz; Carrera, Analía Lorena

    2018-07-15

    Assessing the ability of key species to cope with environmental stresses in disturbed areas is an important issue for recovery of degraded arid ecosystem. Our objective was to evaluate the effect of soil moisture, exposure to UV radiation, and presence/absence of litter with different chemistry on soil N, recruitment and biomass of seedlings of perennial grass (Poa ligularis and Nassella tenuis) and evergreen shrub species (Atriplex lampa and Larrea divaricata) in denuded areas. We carried out a microcosm experiment with soil blocks (28 cm depth) sowed with seeds of the target species, subjected to different levels of litter type (perennial grass-evergreen shrub mixture, evergreen shrub mixture, and no litter), UV radiation (near ambient and reduced UV), and soil water (high: 15-25% and low 5-15%). Periodically, during 6 months, we assessed soil-N (total and inorganic) at two depths and species seedling recruitment at microcosms. Additionally, emerged seedlings of each species were transplanted to individual pots containing soil and subjected to the same previous factors during 12 months. Then, all plants were harvested and biomass assessed. Only inorganic soil-N at the upper soil varied among treatments increasing with the presence of evergreen shrub litter, exposure to ambient UV, and high soil water. Inorganic soil-N, promoted by near ambient UV and high soil water, had a positive effect on recruitment of perennial grasses and A. lampa. Both litter types promoted the recruitment of perennial grasses. Evergreen shrub litter and high soil water promoted the recruitment of L. divaricata. Seedling biomass of perennial grasses increased with high soil water and reduced UV. Ambient UV had positive or null effects on biomass of evergreen shrub seedlings. High soil water increased biomass of L. divaricata seedlings. We concluded that soil water appeared as the most limiting factor for seedling recruitment of all species whereas inorganic soil N limited the

  20. Combined electromagnetic geophysical mapping at Arctic perennial saline springs: Possible applications for the detection of water in the shallow subsurface of Mars

    Science.gov (United States)

    Samson, C.; Mah, J.; Haltigin, T.; Holladay, S.; Ralchenko, M.; Pollard, W.; Monteiro Santos, F. A.

    2017-05-01

    Perennial springs at the Gypsum Hill site on Axel Heiberg Island in the Canadian Arctic (79°24‧N, 90°44‧W) represent a high-fidelity analogue to hydrothermal systems that might exist on Mars. The springs were surveyed using an electromagnetic induction sounder (EMIS) and ground penetrating radar (GPR). Both instruments probed the subsurface to a depth of approximately 3 m. Lateral EMIS soundings were performed every metre along a 400 m long reconnaissance line roughly oriented SW-NE and extending through 23 active springs and 1 dry outlet to measure electrical conductivity. Two distinct zones were identified within the survey area on the basis of these data: in the southwest portion, sharp conductivity peaks correspond to isolated springs with well-defined outlets, flowing over dry rocky soil; in the northeast portion, the springs are fed by a pervasive network of saline fluids, resulting in high background readings and muddy surface conditions. These observations are consistent with vertical EMIS sounding data which showed that the brine body feeding the saline springs can be found closer to the ground surface towards the northeast portion of the survey site. In areas of high electrical conductivity, the GPR data exhibits strong scattering. The noisy areas are sharply defined and interpreted to correspond to narrow vertical conduits feeding individual spring outlets. The EMIS is a rugged instrument that could be included as payload in future rover-based Mars exploration missions aiming at probing the shallow subsurface for the presence of brine pockets.

  1. Diferentes massas de forragem sobre as variáveis morfogênicas e estruturais de azevém anual Different herbage masses on morphogenetic and structural traits of Italian ryegrass

    Directory of Open Access Journals (Sweden)

    Anna Carolina Cerato Confortin

    2013-03-01

    Full Text Available Características morfogênicas e estruturais de azevém (Lolium multiflorum Lam. foram avaliadas sob pastejo de borregas, em diferentes massas de forragem (MF: "Alta", "Média" e "Baixa", correspondentes a 1800-2000; 1400-1600 e 1000-1200kg ha-1 de matéria seca (MS, respectivamente. O delineamento experimental foi inteiramente casualizado, com três tratamentos e duas repetições de área. O método de pastejo foi de lotação contínua, com número variável de animais. Os dados foram submetidos a análises de correlação e regressão polinomial. A altura do pseudocolmo, o comprimento de lâminas intactas e desfolhadas e o número de folhas em senescência de azevém aumentaram linearmente com a elevação dos valores das massas de forragem. O número de folhas verdes ajustou-se ao modelo de regressão quadrático; o número de folhas em expansão e a densidade populacional de perfilhos não se ajustaram a nenhum modelo de regressão. Em pastagem de azevém, o manejo com massas de forragem dentro da faixa compreendida entre 1.100 e 1.800kg ha-1de MS não provoca alterações nas características morfogênicas dessa gramínea, mas causa diferenças nas características estruturais do dossel. Quando o azevém é manejado com 1.460kg ha-1de MS, seus perfilhos mantêm maior número de folhas verdes e com 1.800kg ha-1 de MS existe maior número de lâminas foliares em senescência e com maior comprimento.Morphogenetic and structural characteristics of Italian ryegrass (Lolium multiflorum Lam., utilized by female lambs and managed with different forage masses (FM were studied. The experimental design was completely randomized, with two area replications and three treatments, consisting of forage masses: "High", "Mean" and "Low", corresponding to 1,800-2,000; 1,400-1,600 and 1,000-1,200kg ha-1 of dry matter (DM, respectively. The grazing method was continuous with variable stocking rate. Data were subjected to correlation analysis and polynomial

  2. Producción de biomasa y costos de producción de pastos estrella africana (Cynodon nlemfuensis, kikuyo (Kikuyuocloa clandestina y ryegrass perenne (Lolium perenne en lecherías de Costa Rica

    Directory of Open Access Journals (Sweden)

    Luis Villalobos

    2013-01-01

    Full Text Available Se evaluó la producción de biomasa, los costos de producción y el costo del kilogramo de materia seca en los pastos kikuyo (Kikuyuocloa clandestina, ryegrass perenne (Lolium perenne y estrella africana (Cynodon nlemfuensis, a lo largo de un año, en 8 fincas comerciales ubicadas en las provincias de Cartago (2, San José (2 y Alajuela (4. La producción de biomasa promedio por ciclo para los 3 pastos fue de 3395 kg.ha-1 MS; la producción anual se ve influenciada por los días de recuperación de cada especie, mostrando valores de 40 170, 38 731 y 28 995 kg.ha-1 de MS para los pastos estrella africana, kikuyo y ryegrass perenne, respectivamente. La producción de biomasa varía durante el año y en las épocas de mayor producción de esa biomasa, los animales tienen un menor aprovechamiento de la pastura en términos porcentuales, debido a que la carga animal, los períodos de permanencia y las áreas de pastoreo no se ajustan a la disponibilidad de forraje. Los costos anuales de mano de obra, insumos y tierra promedio fueron de 72.433, 505.515 y 18.760 colones.ha-1, respectiva- mente; siendo los insumos el rubro con un peso relativo mayor en la estructura de costos de las fincas en pastoreo. Los costos del kg de MS producido y consumido, para los 3 pastos evaluados, fueron de 16,6 y 44,4 colones respectivamente, siendo el aprovechamiento que los animales hacen de las pasturas el determinante del costo del material consumido. Las fincas con mayor inversión anual en pasturas, mostraron un mayor retorno en kg.ha-1 leche.

  3. Physiological and morphological adaptations of herbaceous perennial legumes allow differential access to sources of varyingly soluble phosphate.

    Science.gov (United States)

    Pang, Jiayin; Yang, Jiyun; Lambers, Hans; Tibbett, Mark; Siddique, Kadambot H M; Ryan, Megan H

    2015-08-01

    The aim of this study was to investigate the capacity of three perennial legume species to access sources of varyingly soluble phosphorus (P) and their associated morphological and physiological adaptations. Two Australian native legumes with pasture potential (Cullen australasicum and Kennedia prostrata) and Medicago sativa cv. SARDI 10 were grown in sand under two P levels (6 and 40 µg P g(-1) ) supplied as Ca(H2 PO4 )2 ·H2 O (Ca-P, highly soluble, used in many fertilizers) or as one of three sparingly soluble forms: Ca10 (OH)2 (PO4 )6 (apatite-P, found in relatively young soils; major constituent of rock phosphate), C6 H6 O24 P6 Na12 (inositol-P, the most common form of organic P in soil) and FePO4 (Fe-P, a poorly-available inorganic source of P). All species grew well with soluble P. When 6 µg P g(-1) was supplied as sparingly soluble P, plant dry weight (DW) and P uptake were very low for C. australasicum and M. sativa (0.1-0.4 g DW) with the exception of M. sativa supplied with apatite-P (1.5 g). In contrast, K. prostrata grew well with inositol-P (1.0 g) and Fe-P (0.7 g), and even better with apatite-P (1.7 g), similar to that with Ca-P (1.9 g). Phosphorus uptake at 6 µg P g(-1) was highly correlated with total root length, total rhizosphere carboxylate content and total rhizosphere acid phosphatase (EC 3.1.3.2) activity. These findings provide strong indications that there are opportunities to utilize local Australian legumes in low P pasture systems to access sparingly soluble soil P and increase perennial legume productivity, diversity and sustainability. © 2014 Scandinavian Plant Physiology Society.

  4. Genetic and epigenetic differences associated with environmental gradients in replicate populations of two salt marsh perennials

    NARCIS (Netherlands)

    Foust, C.M.; Preite, V.; Schrey, A.W.; Alvarez, M.; Robertson, M.H.; Verhoeven, K.J.F.; Richards, Christina L.

    2016-01-01

    While traits and trait plasticity are partly genetically based, investigating epigenetic mechanisms may provide more nuanced understanding of the mechanisms underlying response to environment. Using AFLP and methylation-sensitive AFLP, we tested the hypothesis that differentiation to habitats along

  5. Pre-harvest assessment of perennial weeds in cereals based on images from unmanned aerial systems (UAS)

    DEFF Research Database (Denmark)

    Egilsson, Jon; Pedersen, Kim Steenstrup; Olsen, Søren Ingvor

    2015-01-01

    Unmanned aerial systems (UAS) are able to deliver images of agricultural fields of high spatial and temporal resolution. It is, however, not trivial to extract quantitative information about weed infestations from images. This study contributes to weed research by using state-of-the-art computer....... In order to provide ground truth prior to the modeling phase in Python, a subset of 600 images was annotated by experts with 16000 regions of weeds or crop. Following this, images were segmented into regions with weeds or crop by subdividing each image into 64 by 64 pixel patches and classifying each patch...... as either crop or weed. A collection of geo-referenced segmented images may subsequently be used to map weed occurrences in fields. To find a robust and fully automated assessment method both texture and color information was used to build a number of different competing weed-crop classifiers, including...

  6. A Proteome Translocation Response to Complex Desert Stress Environments in Perennial Phragmites Sympatric Ecotypes with Contrasting Water Availability.

    Science.gov (United States)

    Li, Li; Chen, Xiaodan; Shi, Lu; Wang, Chuanjing; Fu, Bing; Qiu, Tianhang; Cui, Suxia

    2017-01-01

    After a long-term adaptation to desert environment, the perennial aquatic plant Phragmites communis has evolved a desert-dune ecotype. The desert-dune ecotype (DR) of Phragmites communis showed significant differences in water activity and protein distribution compared to its sympatric swamp ecotype (SR). Many proteins that were located in the soluble fraction of SR translocated to the insoluble fraction of DR, suggesting that membrane-associated proteins were greatly reinforced in DR. The unknown phenomenon in plant stress physiology was defined as a proteome translocation response. Quantitative 2D-DIGE technology highlighted these 'bound' proteins in DR. Fifty-eight kinds of proteins were identified as candidates of the translocated proteome in Phragmites . The majority were chloroplast proteins. Unexpectedly, Rubisco was the most abundant protein sequestered by DR. Rubisco activase, various chaperons and 2-cysteine peroxiredoxin were major components in the translocation response. Conformational change was assumed to be the main reason for the Rubisco translocation due to no primary sequence difference between DR and SR. The addition of reductant in extraction process partially reversed the translocation response, implying that intracellular redox status plays a role in the translocation response of the proteome. The finding emphasizes the realistic significance of the membrane-association of biomolecule for plant long-term adaptation to complex stress conditions.

  7. Perennial grasses as the ecological link for preserving the fertility of the peat soils polluted by radionuclides

    International Nuclear Information System (INIS)

    Podolyak, A.G.; Saraseko, E.G.; Arastovich, T.V.; Suzko, O.V.; Tagaj, S.A.; Lasko, T.V.; Goloveshkin, V.V.

    2011-01-01

    The problem of degradation of peat soils polluted with 137Cs and 90Sr and cultivation of the crop production on them is considered. Distribution of grasslands and pastures on polluted peat soils by the regions of the Republic of Belarus is presented. Characteristics of the peat soils are shown. Coefficients of migration of radionuclides in perennial grasses' hay depending on mobile potassium availability (for 137Cs) and soil reaction pHkci (for 90sr) are evaluated. Inadequacy of the hay, harvested on polluted territories, to the main quality characteristics is presented and analyzed. Crop mixtures recommended for grasslands and pastures reseeding on polluted territories are suggested. The list of cultivars suitable for the conditions of over wetting is offered. It is recommended to use shallow peat soils as grasslands. Permanent cereal grasses restore organic matter of these soils and provide economic efficiency of agricultural use. According the results of the research the transfer factors of 137Cs and 90Sr to plants are relatively low. This fact is explained by the time that has passed since the accident on Chernobyl nuclear power plant and by the variations of mobile potassium and exchangeable acidity in peat soils

  8. Constraints to obtaining consistent annual yields in perennial tree crops. I: Heavy fruit load dominates over vegetative growth.

    Science.gov (United States)

    Smith, Harley M; Samach, Alon

    2013-06-01

    Farmers lack effective methods to achieve and maintain stable production from year to year in many commercial fruit crops. Annual fruit yield within a region often alternates between high and low fruit load and is termed alternate bearing. The underlying cause of alternate bearing is the negative impact of high fruit load on vegetative growth and next year's flowering. In this review, we emphasize common responses of diverse perennials to heavy crop load. We present botanical, ecological and horticultural perspectives on irregular bearing. The later part of this review focuses on understanding how high fruit load dominates over vegetative growth. We discuss sink strengths and putative mobile signals (hormones), perhaps seed-derived. We highlight gaps in current understanding of alternate bearing, and discuss new approaches to better understand fruit load dominance. Assuming the effect of high fruit load may be related to other mechanisms of sink partitioning, other forms of dominance are presented such as apical, first fruit and king fruit dominance. Dominance seems to be enforced, in independent cases through the establishment of a polar auxin transport system from the stronger sink. Once established this somehow perturbs the transport of auxin out of weaker sinks. Possibly, fruit derived auxin may alter the polar auxin transport system of the shoot to inhibit shoot growth. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  9. Energy vectors - Perennial guidebook for energy choices; Vecteurs d'energie - Guide perenne pour les choix energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Caseau, P.; Ruelle, G.; Bacher, P.; Bamberger, Y.; Castillon, P.; Decomps, B.; Dhers, J.; Jarry, B.; Lefaudeux, F.; Mudry, F.; Saunier, B. [Academie des Technologies, Grand Palais des Champs Elysees - Porte C - Avenue Franklin D. Roosevelt - 75008 Paris (France); Careme, F.; Rogeaux, B. [EdF, 22-30, avenue de Wagram 75008 Paris (France); Choux, G. [Total, 2, place Jean Millier La Defense 6, 92400 Courbevoie (France); Morel, H. [CNRS, 3 Rue Michel-Ange, 75016 Paris (France)

    2011-11-17

    Energy vector means the distributed form of energy which is paid by the end-user: the automotive fuel at the gas station, the electricity at the plug. Vectors are characterized by two essential properties: they are structured in networks allowing a large access to users and a geographical and time adjustment of the demand thanks to transport and storage facilities. The link they create between sources and needs allows to introduce both upstream and downstream competitions (what usage is the most profitable? What source or vector is the most economical?). These two properties of vectors allow to use the economical and ecological competitions to help the decision-makers in the choice of the energy mix. This book explores these competitions with a double compass: ecological (greenhouse gases abatement) and economical (the less cost). The parametrical structure of the study allows to use it according to various hypotheses concerning the future evolution of energy source and CO{sub 2} prices. Therefore, it represents a perennial guidebook of energy choices. (J.S.)

  10. Small-scale variations in leaf shape under anthropogenic disturbance in dioecious forest forb mercurialis perennis: A geometric morphometric examination

    Directory of Open Access Journals (Sweden)

    Vujić Vukica

    2016-01-01

    Full Text Available Plants are exposed to increasing levels of diverse human activities that have profound effects on their overall morphology and, specifically, on leaf morphology. Anthropogenic disturbances in urban and suburban forest recreational sites are attracting growing research interest. To explore the persisting recreational impact on leaf shape and size, we conducted a field study on the dioecious forb Mercurialis perennis L. (Euphorbiaceae, typical for undisturbed understory communities. We selected adjacent sites in a suburban forest, which experience contrasting regimes of disturbance by human trampling under otherwise concordant natural conditions. Patterns of leaf shape and size variation and putative sex-specific response to disturbance were analyzed using a geometric morphometric approach. In addition to leaf-level data, plant height, internode and leaf number were analyzed to explore the same response at the whole-plant level. The results show significant variations associated with disturbance at both levels: plants growing under a heavy disturbance regime had shorter stems with a greater number of wider and shorter leaves. Significant differences between sites were also found for leaf size, with larger leaves observed in an undisturbed site. The effects of sex and sex x site interaction on leaf size and shape were nonsignificant, pointing to the absence of sexual dimorphism and sex-specific response to disturbance. Contrary to leaf shape and size, all three analyzed shoot traits showed highly significant sexual dimorphism, with male plants being higher and having higher leaf and internode count. [Projekat Ministarstva nauke Republike Srbije, br. 173025

  11. Perennial grass management impacts on runoff and sediment export from vegetated channels in pulse flow runoff events

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, H.M. [Department of Agriculture and Natural Resources, University of Minnesota-Crookston, 2900 University Avenue, Crookston, MN 56716 (United States); Cruse, R.M.; Burras, C.L. [Agronomy Department, Iowa State University, Ames, IA 50010-1010 (United States)

    2011-01-15

    The goal of the United States Congress is to replace 30% of United States petroleum with biofuels by 2030. If this goal will be accomplished, it is estimated that 25-50% of the land enrolled in the Conservation Reserve Program (CRP) have its biomass removed. However, the purpose of many conservation practices enrolled in CRP is to improve or maintain water quality and not to serve as a source of biomass. This study was conducted to determine if biomass removal has an effect on runoff and sediment export from vegetated channels during low intensity storms that occur frequently. In June 2006, 24 channels were created that measured 2 m x 10 m. The treatments of grass species (big bluestem, corn, smooth bromegrass, and switchgrass) and biomass removal (removed, not removed) were applied to the channels in a split-plot arrangement. Three times in 2007 and 3 more times in 2008, a 787 L load of water with suspended sediment was drained on the head and sides of each experimental unit and the entire load of water that ran off was collected, weighed, and sampled for sediment concentration. Biomass removal increased runoff and sediment by an average of 15% over the two years of the study. The channels planted to perennial C4 grasses were most effective at reducing runoff and sediment export, while the corn was consistently the least effective at reducing runoff and sediment export. (author)

  12. Perennial grass management impacts on runoff and sediment export from vegetated channels in pulse flow runoff events

    International Nuclear Information System (INIS)

    Wilson, H.M.; Cruse, R.M.; Burras, C.L.

    2011-01-01

    The goal of the United States Congress is to replace 30% of United States petroleum with biofuels by 2030. If this goal will be accomplished, it is estimated that 25-50% of the land enrolled in the Conservation Reserve Program (CRP) have its biomass removed. However, the purpose of many conservation practices enrolled in CRP is to improve or maintain water quality and not to serve as a source of biomass. This study was conducted to determine if biomass removal has an effect on runoff and sediment export from vegetated channels during low intensity storms that occur frequently. In June 2006, 24 channels were created that measured 2 m x 10 m. The treatments of grass species (big bluestem, corn, smooth bromegrass, and switchgrass) and biomass removal (removed, not removed) were applied to the channels in a split-plot arrangement. Three times in 2007 and 3 more times in 2008, a 787 L load of water with suspended sediment was drained on the head and sides of each experimental unit and the entire load of water that ran off was collected, weighed, and sampled for sediment concentration. Biomass removal increased runoff and sediment by an average of 15% over the two years of the study. The channels planted to perennial C4 grasses were most effective at reducing runoff and sediment export, while the corn was consistently the least effective at reducing runoff and sediment export. (author)

  13. Omalizumab Is Equally Effective in Persistent Allergic Oral Corticosteroid-Dependent Asthma Caused by Either Seasonal or Perennial Allergens: A Pilot Study.

    Science.gov (United States)

    Domingo, Christian; Pomares, Xavier; Navarro, Albert; Rudi, Núria; Sogo, Ana; Dávila, Ignacio; Mirapeix, Rosa M

    2017-02-28

    Omalizumab is marketed for chronic severe asthma patients who are allergic to perennial allergens. Our purpose was to investigate whether omalizumab is also effective in persistent severe asthma due to seasonal allergens. Thirty patients with oral corticosteroid-dependent asthma were treated with Omalizumab according to the dosing table. For each patient with asthma due to seasonal allergens, we recruited the next two consecutive patients with asthma due to perennial allergens. The dose of oral methyl prednisolone was tapered at a rate of 2 mg every two weeks after the start of treatment with omalizumab depending on tolerance. At each monthly visit, a forced spirometry and fractional exhaled nitric oxide (FeNO) measurement were performed and the accumulated monthly methyl prednisolone dose was calculated. At entry, there were no differences between groups in terms of gender, body mass index or obesity, year exacerbation rate, monthly dose of methyl-prednisolone (MP), FeNO and blood immunoglobuline E (IgE) MP, FeNO and IgE values, or spirometry (perennial: FVC: 76%; FEV₁: 62%; seasonal: FVC: 79%; FEV₁: 70%). The follow-up lasted 76 weeks. One patient in each group was considered a non-responder. Spirometry did not worsen in either group. There was a significant intragroup reduction in annual exacerbation rate and methyl prednisolone consumption but no differences were detected in the intergroup comparison. Omalizumab offered the same clinical benefits in the two cohorts regardless of whether the asthma was caused by a seasonal or a perennial allergen. These results strongly suggest that allergens are the trigger in chronic asthma but that it is the persistent exposure to IgE that causes the chronicity.

  14. Omalizumab Is Equally Effective in Persistent Allergic Oral Corticosteroid-Dependent Asthma Caused by Either Seasonal or Perennial Allergens: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Christian Domingo

    2017-02-01

    Full Text Available Omalizumab is marketed for chronic severe asthma patients who are allergic to perennial allergens. Our purpose was to investigate whether omalizumab is also effective in persistent severe asthma due to seasonal allergens. Thirty patients with oral corticosteroid-dependent asthma were treated with Omalizumab according to the dosing table. For each patient with asthma due to seasonal allergens, we recruited the next two consecutive patients with asthma due to perennial allergens. The dose of oral methyl prednisolone (MP was tapered at a rate of 2 mg every two weeks after the start of treatment with omalizumab depending on tolerance. At each monthly visit, a forced spirometry and fractional exhaled nitric oxide (FeNO measurement were performed and the accumulated monthly MP dose was calculated. At entry, there were no differences between groups in terms of gender, body mass index or obesity, year exacerbation rate, monthly dose of MP, FeNO and blood immunoglobuline E (IgE values, or spirometry (perennial: FVC: 76%; FEV1: 62%; seasonal: FVC: 79%; FEV1: 70%. The follow-up lasted 76 weeks. One patient in each group was considered a non-responder. Spirometry did not worsen in either group. There was a significant intragroup reduction in annual exacerbation rate and MP consumption but no differences were detected in the intergroup comparison. Omalizumab offered the same clinical benefits in the two cohorts regardless of whether the asthma was caused by a seasonal or a perennial allergen. These results strongly suggest that allergens are the trigger in chronic asthma but that it is the persistent exposure to IgE that causes the chronicity.

  15. Tracking Changes in Dissolved Organic Matter Patterns in Perennial Headwater Streams Throughout a Hydrologic Year Using In-situ Sensors and Optical Properties

    Science.gov (United States)

    Armstrong, A.; Epting, S.; Hosen, J. D.; Palmer, M.

    2015-12-01

    Dissolved organic matter (DOM) plays a central role in freshwater streams but key questions remain unanswered about temporal patterns in its quantity and composition. DOM in perennial streams in the temperate zone is a complex mixture reflecting a variety of sources such as leached plant material, organic matter from surrounding soils, and microbial processes in the streams themselves. Headwater perennial streams in the Tuckahoe Creek watershed of the Atlantic coastal plain (Maryland, USA) drain a mosaic of land cover types including row crops, forests, and both forested and marshy small depressional wetlands. Wetland-stream surface hydrologic connections generally occur between mid-fall and late spring, coinciding with peak wetland hydrologic expression (i.e. highest groundwater levels and surface inundation extent). When inundated, these wetlands contain high DOM concentrations, and surface connections may serve as conduits for downstream export. We hypothesized that changes in wetland-stream surface hydrologic connectivity would affect patterns of DOM concentration and composition in these streams. We deployed 6 sondes equipped with fluorescent DOM sensors in 4 perennial streams, 1 forested wetland, and the larger downstream channel draining all study sites for the 2015 water year. The 4 headwater streams drain areas containing forested wetlands and have documented temporary channel connections. Combined with baseflow and stormflow sampling, the sondes provided 15 minute estimates of dissolved organic carbon (DOC) concentrations. This resolution provided insights into patterns of DOC concentration across temporal scales from daily rhythms to seasonal changes, during both baseflow and storm conditions. Discrete measurements of absorbance and fluorescence provided information about DOM composition throughout the study. Together these measurements give a detailed record of DOM dynamics in multiple perennial headwater streams for an entire year. This information

  16. The optimal CO2 concentrations for the growth of three perennial grass species

    OpenAIRE

    Zheng, Yunpu; Li, Fei; Hao, Lihua; Shedayi, Arshad Ali; Guo, Lili; Ma, Chao; Huang, Bingru; Xu, Ming

    2018-01-01

    Background Grasslands are one of the most representative vegetation types accounting for about 20% of the global land area and thus the response of grasslands to climate change plays a pivotal role in terrestrial carbon balance. However, many current climate change models, based on earlier results of the doubling-CO2 experiments, may overestimate the CO2 fertilization effect, and as a result underestimate the potentially effects of future climate change on global grasslands when the atmospher...

  17. TrMADS3, a new MADS-box gene, from a perennial species Taihangia rupestris (Rosaceae) is upregulated by cold and experiences seasonal fluctuation in expression level.

    Science.gov (United States)

    Du, Xiaoqiu; Xiao, Qiying; Zhao, Ran; Wu, Feng; Xu, Qijiang; Chong, Kang; Meng, Zheng

    2008-06-01

    In many temperate perennial plants, floral transition is initiated in the first growth season but the development of flower is arrested during the winter to ensure production of mature flowers in the next spring. The molecular mechanisms of the process remain poorly understood with few well-characterized regulatory genes. Here, a MADS-box gene, named as TrMADS3, was isolated from the overwintering inflorescences of Taihangia rupestris, a temperate perennial in the rose family. Phylogenetic analysis reveals that TrMADS3 is more closely related to the homologs of the FLOWERING LOCUS C lineage than to any of the other MIKC-type MADS-box lineages known from Arabidopsis. The TrMADS3 transcripts are extensively distributed in inflorescences, roots, and leaves during the winter. In controlled conditions, the TrMADS3 expression level is upregulated by a chilling exposure for 1 to 2 weeks and remains high for a longer period of time in warm conditions after cold treatment. In situ hybridization reveals that TrMADS3 is predominantly expressed in the vegetative and reproductive meristems. Ectopic expression of TrMADS3 in Arabidopsis promotes seed germination on the media containing relatively high NaCl or mannitol concentrations. These data indicate that TrMADS3 in a perennial species might have its role in both vegetative and reproductive meristems in response to cold.

  18. Effect of cigarette smoke on counts of immunoreactive cells to eotaxin-1 and eosinophils on the nasal mucosa in young patients with perennial allergic rhinitis.

    Science.gov (United States)

    Montaño-Velázquez, Bertha Beatriz; Flores-Rojas, Eulalia Beatriz; García-Vázquez, Francisco Javier; Jurado-Hernandez, Silvio; Venancio Hernández, Marco Antonio; Alanis Flores, Angélica Kathya; Jáuregui-Renaud, Kathrine

    In teenagers with perennial allergic rhinitis, exposure to tobacco cigarette smoke increases the count of eosinophils in the nasal mucosa; the recruitment of eosinophils arises from the combined action of a number of cellular and molecular signals, including eotaxin. To assess the effect of exposure to tobacco cigarette smoke on the count of immunoreactive cells to eotaxin-1 and eosinophils on the nasal mucosa of children and teenagers with perennial allergic rhinitis. In a cross-sectional study, forty-four patients were evaluated (aged 7-19 years old): 22 with and 22 with no exposure to tobacco cigarette smoke. After replying to 2 validated questionnaires, on Asthma and Allergies in Childhood and on the severity of nasal symptoms, nasal mucosal samples were obtained by scraping the middle one-third of the inferior turbinates. Then counts of immunoreactive cells to eotaxin-1 and eosinophils were assessed by immunohistochemistry. Patients with exposure to tobacco cigarette smoke showed higher cell counts of both eotaxin-1 and eosinophils than patients with no exposure to the smoke, with no correlation between the two variables. However, both counts, of eotaxin-1 and eosinophils, were related to the cotinine/creatinine ratio. Exposure to tobacco cigarette smoke can increase eotaxin-1 and the count of eosinophils in the nasal mucosa of young patients with perennial allergic rhinitis. Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  19. Evaluación agronómica y nutricional del pasto Ryegrass perenne tetraploide (Lolium perenne producido en lecherías de las zonas altas de Costa Rica. I. Producción de biomasa y fenología

    Directory of Open Access Journals (Sweden)

    Luis Villalobos

    2010-01-01

    3090 msnm, provincia de Cartago. La disponibilidad de materia seca pre y pos-pastoreo, el aprovechamiento por hectárea y su porcentaje de utilización promedio para todas las fincas fueron 4110, 2276 y 1833 kg.ha-1 por corte y 44,82%, respectivamente. La edad fenológica y la relación hoja: tallo promedio de las pasturas de ryegrass perenne fueron 2,84 hojas verdes por rebrote, 56:44. Asimismo, la composición promedio de la pradera fue 76,09% ryegrass, 13,76% otras gramíneas (principalmente pasto kikuyo, 6,02% trébol, 1,25% malezas y 2,88% material senescente, respectivamente. La mayor producción de biomasa durante marzo y abril puede conservarse para utilizarse durante las épocas críticas de disponibilidad de forraje o cuando por razones climatológicas se reduce el número de horas efectivas de pastoreo. La evaluación de la edad fenológica en que se pastorea el pasto ryegrass perenne, indica que las fincas en la zona de estudio utilizan esta gramínea en un estado en el que sus reservas de carbohidratos se han recuperado, lo que permite obtener una producción de biomasa y valor nutricional adecuados para satisfacer las necesidades del ganado lechero de la zona.

  20. How Vulnerable is Perennial Sea Ice? Insights from Earth's Late Cenozoic Natural Experiments (Invited)

    Science.gov (United States)

    Brigham-Grette, J.; Polyak, L. V.; Caissie, B.; Sharko, C. J.; Petsch, S.

    2010-12-01

    Sea ice is an important component of the climate system. Yet, reconstructions of Arctic sea ice conditions reflecting glacial and interglacial change over the past 3 million years are almost nonexistent. Our work to evaluate the sea ice and sea surface temperature record of the Bering Strait region builds on a review of the sea ice history of the pan-Arctic. The best estimates of sea ice make use of indirect proxies based on reconstructions of treeline, sea surface temperatures, depositional systems, and the ecological preferences of extant marine microfossil species. The development of new proxies of past sea ice extent including microfossil assemblages (diatoms, ostracodes) and biomarker proxies (IP25) show promise for quantifying seasonal concentrations of sea ice cover on centennial to millennial timescales. Using both marine and terrestrial information, periods of restricted sea ice and ice-free Arctic conditions can be inferred for parts of the late Cenozoic. The Arctic Ocean borderlands contain clear stratigraphic evidence for forested conditions at intervals over the past 50 million years, recording the migration of treeline from High Arctic coastal locations within the Canadian Archipelago. Metasequoia forests of the peak Eocene gave way to a variety of biomass-rich circumarctic redwood forests by 46 Ma. Between 23 and 16 Ma, cool-temperate metasequoia forests dominated NE Alaska and the Yukon while mixed conifer-hardwood forests (similar to those of modern southern maritime Canada and New England) dominated the central Canadian Archipelago. By 16 Ma, these forests gave way to larch and spruce. From 5 to 3 Ma the braid plains of the Beaufort Fm were dominated by over 100 vascular plants including pine and birch, while other locations remained dominated by spruce and larch. Boreal conditions across northern Greenland and arctic Alaska are consistent with the presence of bivalve Arctica islandica in marine sediments capping the Beaufort Formation on Meighen