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discovery and genetic mapping of single nucleotide polymorphisms in candidate genes for pathogen defence response in perennial ryegrass (lolium perenne l.).susceptibility to foliar pathogens commonly causes significant reductions in productivity of the important temperate forage perennial ryegrass. breeding for durable disease resistance involves not only the deployment of major genes but also the additive effects of minor genes. an approach based on in vitro single nucleotide polymorphism (snp) discovery in candidate defence response (dr) genes has been used to develop potential diagnostic genetic markers. snps were predicted, validated and mapped ...200818446316
45s rdna regions are chromosome fragile sites expressed as gaps in vitro on metaphase chromosomes of root-tip meristematic cells in lolium spp.in humans, chromosome fragile sites are regions that are especially prone to forming non-staining gaps, constrictions or breaks in one or both of the chromatids on metaphase chromosomes either spontaneously or following partial inhibition of dna synthesis and have been well identified. so far, no plant chromosome fragile sites similar to those in human chromosomes have been reported.200818478113
maldi-tof ms analysis of labile lolium perenne major allergens in mixes.it is well known that allergen extracts used for specific therapy of allergic disorders are commonly stored as mixtures, causing an alteration of its stability.200818503569
molecular characterization of lolium latent virus, proposed type member of a new genus in the family flexiviridae.lolium latent virus (lolv) was recently detected in the usa for the first time in ryegrass hybrids (lolium perenne x lolium multiflorum). the genome of one usa isolate, lolv-us1, has now been fully sequenced. the positive strand genomic rna is 7674 nucleotides (nt) long and is organized in five open reading frames (orfs) encoding the replication-associated protein, the movement-associated triple gene block proteins and the coat protein (cp). the genome organization is similar to that of viruses ...200818509590
wet oxidation pretreatment, enzymatic hydrolysis and simultaneous saccharification and fermentation of clover-ryegrass mixtures.the potential of clover (trifolium repens) and ryegrass (lolium perenne) mixtures as raw materials for ethanol production was investigated. wet oxidation, at 175, 185 or 195 degrees c during 10min at two different oxygen pressures and with either addition or no addition of sodium carbonate, was evaluated as pretreatment method for clover-ryegrass mixtures. the enzymatic hydrolysis of cellulose was significantly improved after pretreatment. the highest conversion efficiency, 93.6%, was achieved f ...200818514510
effect of in situ soil amendments on arsenic uptake in successive harvests of ryegrass (lolium perenne cv elka) grown in amended as-polluted soils.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 (alpha-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 ...200818524441
effects of amended compost on mobility and uptake of arsenic by rye grass in contaminated soil.arsenic poses a major environmental and human health problem because of its carcinogenic nature and effect on the ecosystem. therefore, a cost effective and socially acceptable technique is needed for its remediation. the effect of different combinations of compost amended with zeolite and/or iron oxide (up to 20% w/w) was tested on a contaminated soil with high arsenic levels (34470 mg kg(-1)). the bioavailability of arsenic was determined in terms of uptake by rye grass (lolium perenne l.) und ...200818538368
trophic cascades initiated by fungal plant endosymbionts impair reproductive performance of parasitoids in the second generation.variation in plant quality can transmit up the food chain and may affect herbivores and their antagonists in the same direction. fungal endosymbionts of grasses change the resource quality by producing toxins. we used an aphid-parasitoid model system to explore how endophyte effects cascade up the food chain and influence individual parasitoid performance. we show that the presence of an endophyte in the grass lolium perenne has a much stronger negative impact on the performance of the parasitoi ...200818636277
dynamics of initial colonization of nonconserved perennial ryegrass by anaerobic fungi in the bovine rumen.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 ...200818673390
co-digestion of animal slurry can increase short-term nitrogen recovery by crops.co-digestion changes slurry characteristics and is supposed to increase short-term nitrogen (n) uptake by crops after application. a higher n uptake from slurry reduces the need for additional mineral n fertilizer. if farmers apply co-digested slurry (cs), a higher n recovery has to be taken into account to prevent losses to the environment. since data on the effects of co-digestion on n recovery by crops are scarce, a pot experiment was performed. the apparent n recovery (anr) of five different ...200818689758
impact of sheep urine deposition and plant species on ammonia-oxidizing bacteria in upland grassland soil.the effects of different concentrations of synthetic sheep urine and plant species on ammonia-oxidizing bacterial (aob) communities in an upland grassland soil were investigated using a microcosm approach. plant species characteristic of unimproved and improved agricultural pastures (agrostis capillaris and lolium perenne, respectively) were planted in soil microcosms, and different levels of synthetic sheep urine were applied, with harvests 10 and 50 days following urine application. shifts in ...200818772943
effects of increasing days of exposure to prepartum transition diets on milk production and milk composition in dairy cows.to evaluate the effects of length of exposure to prepartum transition diets on milk yield, fat and protein production.200818782415
the molecular mechanism of "ryegrass staggers," a neurological disorder of k+ channels."ryegrass staggers" is a neurological condition of unknown mechanism that impairs motor function in livestock. it is caused by infection of perennial ryegrass pastures by an endophytic fungus that produces neurotoxins, predominantly the indole-diterpenoid compound lolitrem b. animals grazing on such pastures develop uncontrollable tremors and become uncoordinated in their movement. lolitrem b and the structurally related tremor inducer paxilline both act as potent large conductance calcium-activ ...200818801945
characterization of a family of ice-active proteins from the ryegrass, lolium perenne.five genes coding for ice-active proteins were identified from an expressed sequence tag database of lolium perenne cdna libraries. each of the five genes were characterized by the presence of an n-terminal signal peptide, a region enriched in hydrophilic amino acids and a leucine-rich region in four of the five genes that is homologous with the receptor domain of receptor-like protein kinases of plants. the c-terminal region of all five genes contains sequence homologous with lolium and triticu ...200818835384
plant-endophyte-herbivore interactions: more than just alkaloids?a recent paper by rasmussen et al., (new phytol 2007; 173:787-97) describes the interactions between lolium perenne cultivars with contrasting carbohydrate content and the symbiotic fungal endophyte neotyphodium lolii at different levels of nitrogen supply. in a subsequent study undertaken by rasmussen et al., (plant physiol 2008; 146:1440-53) 66 metabolic variables were analysed in the same material, revealing widespread effects of endophyte infection, n supply and cultivar carbohydrate content ...200819704424
larval survival of fuller's rose weevil, naupactus cervinus, on common groundcover species in orchards of new zealand kiwifruit.fuller's rose weevil, naupactus cervinus (boheman) (curculionidae: entiminae), is an important quarantine pest of new zealand kiwifruit exported to asian markets. both adults and larvae are considered to be polyphagous. in this study, the survival of larval n. cervinus was estimated on common groundcover species of kiwifruit (actinidia spp.) in the bay of plenty, the main region in new zealand where kiwifruit is grown. the botanical composition of groundcover in commercial kiwifruit orchards, ch ...200820298112
host genotype overrides fungal endophyte infection in influencing tiller and spike production of lolium perenne (poaceae) in a common garden experiment.leaves of many cool-season grasses are infected by endophytic fungi that can impact their populations. a common garden experiment with lolium perenne was established in a lawn in new jersey, usa, to investigate the impact of endophyte infection and host genotype on tiller and spike production over three years. infected (e+) and uninfected (e-) plants of each genotype were monitored every 2-3 mo. infection intensity within plants varied significantly among genotypes and years, but there was no ev ...200821632426
fungal endophyte production of reactive oxygen species is critical for maintaining the mutualistic symbiotic interaction between epichloë festucae and perennial ryegrass.key requirements for microbes to initiate and establish mutualistic symbiotic interactions with plants are evasion of potential host defense responses and strict control of microbial growth. we have recently shown that reactive oxygen species (ros) produced by a specific fungal nadph oxidase isoform noxa, have a critical role in regulating hyphal growth in the mutualistic interaction between epichloë festucae and perennial ryegrass. regulation of ros production in the symbiosis requires two addi ...200719704747
peramine and other fungal alkaloids are exuded in the guttation fluid of endophyte-infected grasses.many grasses live in association with asymptomatic fungi (neotyphodium spp. endophytes), which grow in the intercellular spaces of the grass. these endophytes produce a range of alkaloids that protect the grass against grazing by mammals and insects. one of these alkaloids is an unusual pyrrolopyrazine, peramine. peramine appears to be continuously produced by the endophyte, but does not progressively accumulate. no mechanism for the removal of peramine by its further metabolism or any other pro ...200717126863
study on the influence of pasture on volatile fraction of ewes' dairy products by solid-phase microextraction and gas chromatography-mass spectrometry.the detection of markers of identification of the geographical origin of food is an attractive challenge and, as far as dairy products are concerned, this paper represents a contribution to this field. in this research the influence of feed on the volatile compound composition was investigated on milk, 2-mo-old cheese (caciotta), and whey cheese (ricotta) obtained from the same flock of sarda ewes, under standardized technological conditions. three different types of pasture (mixture of lolium p ...200717235132
comparative evaluation of alternative forages to grass silage in the diet of early lactation dairy cows.fifty-six autumn-calving holstein-friesian cows, blocked on the basis of days in milk (27.6 +/- 10.65 d), lactation number (3.1 +/- 2.21), and preexperimental milk yield (28.4 +/- 6.69 kg) were used to examine the effects of replacing 330 g/kg of dry matter (dm) of first-cut perennial ryegrass silage with either fermented whole-crop wheat (wcw), urea-treated processed wcw, or corn silage on subsequent feed intake, milk production, and efficiency of nitrogen utilization. the dm (g/kg), crude prot ...200717235167
high nitrogen supply and carbohydrate content reduce fungal endophyte and alkaloid concentration in lolium perenne.the relationship between cool-season grasses and fungal endophytes is widely regarded as mutualistic, but there is growing uncertainty about whether changes in resource supply and environment benefit both organisms to a similar extent. here, we infected two perennial ryegrass (lolium perenne) cultivars (aberdove, fennema) that differ in carbohydrate content with three strains of neotyphodium lolii (ar1, ar37, common strain) that differ intrinsically in alkaloid profile. we grew endophyte-free an ...200717286827
functional analysis of a beta-1,6-glucanase gene from the grass endophytic fungus epichloë festucae.beta-1,6-glucanases degrade the polysaccharide beta-1,6-glucan, a cell wall component in some filamentous fungi. a single copy of a beta-1,6-glucanase gene, designated gcna, was identified in each of the grass endophytic fungi neotyphodium lolii and epichloë festucae. phylogenetic analysis indicates that the gcna protein is a member of glycosyl hydrolase family 5, and is closely related to fungal beta-1,6-glucanases implicated in mycoparasitism. the e. festucae gcna gene was expressed in myceliu ...200717303450
identification of two novel phytosiderophores secreted by perennial grasses.it has been suggested that some perennial grasses secrete phytosiderophores in response to iron (fe) deficiency, but the compounds have not been identified. here, we identified and characterized the phytosiderophores secreted by two perennial grasses, lolium perenne cv. tove and poa pratensis cv. baron. root exudates were collected from the roots of fe-deficient grasses and then purified with various chromatographies. the structure of the purified compounds was determined using both nuclear magn ...200717388893
resistance to rust fungi in lolium perenne depends on within-species variation and performance of the host species in grasslands of different plant diversity.the hypothesis that plant species diversity and genetic variation of the host species decrease the severity of plant diseases is supported by studies of agricultural systems, but experimental evidence from more complex systems is scarce. in an experiment with grassland communities of varying species richness (1, 2, 4, 8, 16, and 60 species) and functional group richness (1, 2, 3, and 4 functional groups), we used different cultivars of lolium perenne (perennial ryegrass) to study effects of biod ...200717415594
anthelmintic and nutritional effects of heather supplementation on cashmere goats grazing perennial ryegrass-white clover pastures.to investigate anthelmintic and nutritional effects of heather supplementation in goats grazing perennial ryegrass-white clover pastures, 40 dry cashmere goats were randomly assigned to 4 treatments in a 2 x 2 factorial arrangement: 2 grazing management treatments (supplementation with heather vs. nonsupplementation) and 2 anthelmintic treatments (treatment vs. nontreatment). goats grazed continuously from may to september 2004. at the end of the grazing period, the number of dead goats due to g ...200717085731
interaction of bioaccumulation of heavy metal chromium with water relation, mineral nutrition and photosynthesis in developed leaves of lolium perenne l.contamination by chromium (cr) is widespread in agricultural soils and industrial sites. this heavy metal represents a risk to human health. in order to gain fundamental insights into the nature of the adaptation to cr excess, the characterisation of physiological indices, including responses of photosynthetic gas exchange and chlorophyll a fluorescence along with changes in mineral nutrient contents and water status were studied in ray grass (lolium perenne l.). increased concentrations of cr(v ...200717434568
comparative toxicity of hydrophobic contaminants to microalgae and higher plants.to enable rapid and sensitive screening of phytotoxic compounds in terrestrial system, a 4 day solid-phase microalgal bioassay was developed. three species of microalgae (selenastrum capricornutum, chlorococcum hypnosporum and chlorococcum meneghini) were chosen to investigate their responses to ddts (ddt, ddd and dde) and pahs (naphthalene, phenanthrene and pyrene) spiked sands. the bioassay results showed that pahs and ddts were toxic to microalgae in a 4-day exposure tests but not to seed ger ...200717436149
tobacco as an allergen in bronchial disease.skin testing and sera measurements have verified the existence of tobacco specific ige. however, the few published studies on this matter report conflicting results concerning their clinical significance.200717458428
optimal choice of dairy forages in eastern australia.although several forage species such as perennial ryegrass are predominant, there is a wide range of forage species that could be grown in subtropical and temperate regions in australia as dairy pastures. these species have differing seasonal patterns of growth, nutrient quality, and water-use efficiency, as demonstrated in a large experiment evaluating over 30 species at the university of sydney (camden, new south wales, australia). some species can be grazed, whereas others require mechanical ...200717517747
biogenic amine production in grass, maize and total mixed ration silages inoculated with lactobacillus casei or lactobacillus buchneri.to investigate the effects of inoculating lactobacillus casei or lacobacillus buchneri on the production of biogenic amines (ba) in silage.200717650192
feeding strategies for small-scale dairy systems based on perennial (lolium perenne) or annual (lolium multiflorum) ryegrass in the central highlands of mexico.small-scale dairying is an option for campesinos in mexico. the costs of feeding are high and strategies based on quality forages are a priority. the performance, agronomic variables and feeding costs were evaluated for dairy cows continuously grazing perennial ryegrass-white clover for 9 h/day (prg) or fed cut herbage from annual ryegrass for 8 weeks followed by 9 h/day for 6 weeks on a tethered rotational grazing pattern (arg). all cows received 3 kg/day of an 18% crude protein (cp) concentrat ...200717691542
effects of rumen or duodenal glucose infusions on intake in dairy cows fed fresh perennial ryegrass indoors.the aim of this study was to determine whether the intake of fresh highly digestible ryegrass could be limited by the total amount of energy absorbed. moreover, it investigated whether the limitation was more specific to energy absorbed as volatile fatty acids in the rumen compared with energy absorbed in the lower gastrointestinal tract. four treatments were compared: infusion of 1.25 kg of glucose into the rumen (r1.25), infusion of 2.5 kg of glucose into the rumen (r2.5), infusion of 1.5 kg o ...200717699060
characterization of the dynamics of initial bacterial colonization of nonconserved forage in the bovine rumen.microbial colonization is central to ruminal degradation of dietary material yet little is known about the dynamics of this process. the aim of this study was to characterize the initial stages of bacterial colonization of forage, and to assess the impact that different postsample processing and analysis methods had on the results obtained. bacterial 16s rrna gene-based analysis of damaged, nonconserved perennial ryegrass, incubated in sacco in the bovine rumen, required the development and vali ...200717941835
effective rumen degradation of dry matter, crude protein and neutral detergent fibre in forage determined by near infrared reflectance spectroscopy.the objective of the present study was to examine if near infrared reflectance spectroscopy (nirs) could be used to predict degradation parameters and effective degradation from scans of original forage samples. degradability of dry matter (dm), crude protein (cp) and neutral detergent fibre (ndf) of 61 samples of perennial ryegrass (lolium perenne l.) and orchardgrass (dactylis glomerata l.) was tested by using the in situ technique. the grass samples were harvested at three different stages, e ...200717988354
mapping and comparative analysis of qtl for crown rust resistance in an italian x perennial ryegrass population.abstract crown rust (puccinia coronata f. sp. lolli) is a serious fungal foliar disease of perennial ryegrass (lolium perenne l.) and italian ryegrass (l. multiflorum lam.), which are important forage and turf species. a number of quantitative trait loci (qtl) for crown rust resistance previously were identified in perennial ryegrass under growth chamber or greenhouse conditions. in this study, we conducted a qtl mapping for crown rust resistance in a three-generation italian x perennial ryegras ...200718943608
tilletia vankyi, a new species of reticulate-spored bunt fungus with non-conjugating basidiospores infecting species of festuca and lolium.a bunt fungus, exhibiting a spore germination pattern unique to known reticulate-spored species of tilletia was found infecting plants in seed production fields of festuca rubra ssp. rubra (red fescue) and f. rubra ssp. fallax (chewing's fescue) in oregon, and in seed lots of lolium perenne (perennial ryegrass) from australia and germany. teliospores germinated to form 20-40 uninucleate, non-conjugating basidiospores, and colonies derived from single basidiospores produced teliospores in culture ...200718023991
expression analysis of rice defense-related genes in turfgrass in response to magnaporthe grisea.abstract magnaporthe grisea (anamorph = pyricularia grisea) causes blast on rice (oryza sativa) and gray leaf spot on turfgrass. gray leaf spot is a serious disease on st. augustinegrass (stenotaphrum secundatum), perennial ryegrass (lolium perenne), and tall fescue (festuca arundinacea). virulence assays performed in this study revealed that m. grisea collected from rice could also cause disease on st. augustinegrass and tall fescue. one rice isolate, che86061, caused similar disease reactions ...200718944372
rice pseudomolecule-anchored cross-species dna sequence alignments indicate regional genomic variation in expressed sequence conservation.various methods have been developed to explore inter-genomic relationships among plant species. here, we present a sequence similarity analysis based upon comparison of transcript-assembly and methylation-filtered databases from five plant species and physically anchored rice coding sequences.200717708759
allelopathic effects of medicago sativa l. and vicia cracca l. leaf and root extracts on weeds.in this study, the allelopathic potential of different concentration (5, 25 and 50%) of m. sativa and v. cracca leaf and root extracts were evaluated on germination and radicle length of four weed species (amaranthus retroflexus l., lolium perenne l., ipomoea hederacea l. and portulaca oleracea l.) in laboratory condition. as a result, germination and radicle length of all species were reduced by the extract from m. sativa and v. cracca leaf and root at different percentage. increasing the water ...200719086510
evaluation of a cost effective technique for treating aquaculture water discharge using lolium perenne lam as a biofilter.wastewater stabilization ponds generate low cost by-products that are useful for agriculture. the utilization of these by-products for soil amendment and as a source of nutrients for plants requires a high level of sanitation and stabilization of the organic matter, to maintain acceptable levels of soil, water and air quality. in this study, two aquaculture wastewater treatment systems; recirculating system and a floating plant bed system were designed to improve the quality of irrigation water ...200717966513
phytotoxicity data safeguard the performance of the recipient plants in leachate irrigation.leachates from an operating and a closed landfill were examined for their phytotoxicity by seed germination/root elongation tests using seeds of brassica chinensis and lolium perenne. their ec50s ranged from 3% to 46% v/v, which varied remarkably with the operating status of the landfills. seedlings of twelve tree species were grown in pots, which were irrigated with landfill leachate at the ec50 levels, with tap water as control. no tree mortality or growth inhibition was observed after 90 days ...200716701930
meat quality of lambs of indigenous dairy greek breeds as influenced by dietary protein and gastrointestinal nematode challenge.the effect of dietary protein and gastrointestinal (gi) parasitism on growth and meat quality of lambs was assessed using 60 animals. the lambs were randomly allocated to one of three treatment groups (n=20): group a, which served as control, group b that was regularly treated with albendazole and group c, which was given supplementary feeding with dietary protein. the three groups of lambs grazed into a pasture (lolium perenne), which was contaminated with l(3) larvae of gi nematodes. lamb grow ...200722061258
effects of the arbuscular mycorrhizal fungus glomus mosseae on growth and metal uptake by four plant species in copper mine tailings.a greenhouse experiment was conducted to evaluate the potential role of arbuscular mycorrhizal fungi (amf) in encouraging revegetation of copper (cu) mine tailings. two native plant species, coreopsis drummondii and pteris vittata, together with a turf grass, lolium perenne and a leguminous plant trifolium repens associated with and without amf glomus mosseae were grown in cu mine tailings to assess mycorrhizal effects on plant growth, mineral nutrition and metal uptake. results indicated that s ...200716764975
effects of dietary sulphur sources on concentrations of hydrogen sulphide in the rumen head-space gas of dairy cows.three change-over design experiments investigated the origin of hydrogen sulphide in the rumen head-space gas of dairy cows, comparing the effects of single iso-s additions of methionine, cysteine and sodium sulphate, as well as the effects of single meals of fresh ryegrass or white clover. the concentration of hydrogen sulphide in rumen gas declined close to zero within 4 h after withdrawal of the previous feed. sulphur sources were then given to cows and concentrations of hydrogen sulphide rec ...200722444410
screening of pahs and ddts in sand and acrisols soil by a rapid solid-phase microalgal bioassay.previously we have demonstrated the rapid screening potential of a newly developed solid-phase microalgal bioassay with spiked sands. in this paper, we report further comparative results using both pahs and ddts spiked sands and field-collected acrisols soils. toxicity responses obtained from standard higher plant tests with three species of plants (lolium perenne, cynodon dactylon and brassica chinensis) were compared with those obtained from a cocktail of microalgae (selenastrum capricornutum, ...200717503178
frequency, type, and distribution of est-ssrs from three genotypes of lolium perenne, and their conservation across orthologous sequences of festuca arundinacea, brachypodium distachyon, and oryza sativa.simple sequence repeat (ssr) markers are highly informative and widely used for genetic and breeding studies in several plant species. they are used for cultivar identification, variety protection, as anchor markers in genetic mapping, and in marker-assisted breeding. currently, a limited number of ssr markers are publicly available for perennial ryegrass (lolium perenne). we report on the exploitation of a comprehensive est collection in l. perenne for ssr identification. the objectives of this ...200717626623
effects, transfer, and fate of rdx from aged soil in plants and worms.the objectives of this study were to provide data that can be used to predict exposure-based effects of rdx in aged soil on multiple endpoint organisms representing two trophic levels. these data can be used for defining criteria or reference values for environmental management and conducting specific risk assessment. dose-response experiments formed the basis for the evaluation of toxic effects and transfer of contaminants from soil into two trophic levels. long-term exposure tests were conduct ...200616045966
fractional and structural characterization of hemicelluloses from perennial ryegrass (lolium perenne) and cocksfoot grass (dactylis glomerata).sequential three-stage treatments with 80% etoh containing 0.2% naoh, 2.5% h2o2-0.2% edta containing 1.5% naoh and 2.5% h2o2-0.2% taed containing 1.0% naoh at 75 degrees c for 3h released 8.0% and 10.4%, 79.1% and 77.0% and 12.9% and 12.5% of the original hemicelluloses from perennial grass and cocksfoot grass, respectively. it was found that the four alkaline peroxide-soluble hemicellulosic fractions contained higher amounts of xylose (33.4-38.2%), uronic acids (9.3-15.3%) and rhamnose (3.0-3.9 ...200616750181
a complex gene cluster for indole-diterpene biosynthesis in the grass endophyte neotyphodium lolii.lolitrems are a structurally diverse group of indole-diterpene mycotoxins synthesized by epichloë/neotyphodium endophytes in association with pooid grasses. using suppression subtractive hybridization combined with chromosome walking, two clusters of genes for lolitrem biosynthesis were isolated from neotyphodium lolii, a mutualistic endophyte of perennial ryegrass. the first cluster contains five genes, ltmp, ltmq, ltmf, ltmc, and ltmb, four of which appear to be orthologues of functionally cha ...200616765617
transformation of the ryegrass endophyte neotyphodium lolii can alter its in planta mycelial morphology.the fungus neotyphodium lolii grows in the intercellular spaces of perennial ryegrass as a mutualistic endosymbiont. one of the benefits it conveys to the plant is the production of alkaloids toxic to herbivores. we wanted to determine in planta expression patterns of the n. lolii 3-hydroxy-3-methylglutaryl-coa reductase (hmg coa reductase) gene, believed to be involved in the synthesis of two of these alkaloid toxins, lolitrem b and ergovaline. we transformed the n. lolii strain lp19 with plasm ...200616769511
effects of ergot alkaloids on food preference and satiety in rabbits, as assessed with gene-knockout endophytes in perennial ryegrass (lolium perenne).neotyphodium species are fungal endophytes best known for their protection of grass hosts and production of bioactive metabolites including ergot alkaloids. perennial ryegrass-neotyphodium sp. lp1 symbiota that have altered ergot alkaloid profiles (resulting from knockouts in two different endophyte genes) were fed, along with controls, to rabbits to test the effects of ergot alkaloids on food preference and satiety. interestingly, rabbits dramatically preferred plants that were endophyte-infect ...200616787001
assessment of ecotoxicological risks related to depositing dredged materials from canals in northern france on soil.the implementation of an ecological risk assessment framework is presented for dredged material deposits on soil close to a canal and groundwater, and tested with sediment samples from canals in northern france. this framework includes two steps: a simplified risk assessment based on contaminant concentrations and a detailed risk assessment based on toxicity bioassays and column leaching tests. the tested framework includes three related assumptions: (a) effects on plants (lolium perenne l.), (b ...200616797071
suitability of various turfgrass species and cultivars for development and survival of black cutworm (lepidoptera: noctuidae).black cutworm, agrotis ipsilon (hufnagel) (lepidoptera: noctuidae), feeding bioassays were conducted on young and mature turfgrass species to determine their potential resistance. measures of resistance included larval weight, survival rate, instar development, pupal weight, duration of pupation, and days to pupation and adult emergence. black cutworm reared on poa pratensis 'midnight', poa arachnigera 'tejas', and poa pratensis x poa arachnigera 'reveille' exhibited slower development, lower we ...200616813321
the effect of mixed or sequential grazing of cattle and sheep on the faecal egg counts and growth rates of weaned lambs when treated with anthelmintics.an experiment was conducted over two successive years (2002 and 2003) to investigate the effects of grazing improved permanent pasture (mainly perennial ryegrass/white clover) by cattle or sheep, either sequentially or mixed, on the faecal egg counts and growth rates of weaned lambs when treated with anthelmintics. the grazing season was divided into two parts, may-july then july-october, relating to the pre- and post-weaning of the lambs. four grazing regimes, replicated three times, were compa ...200616887269
effects of perennial ryegrass cultivars on milk yield and nitrogen utilization in grazing dairy cows.the effects of 4 diploid perennial ryegrass cultivars that differed in water-soluble carbohydrate (wsc) concentrations on milk yield and nitrogen (n) utilization in dairy cows were evaluated in a 2-yr grazing experiment. twelve lactating dairy cows were assigned to 1 cultivar for a 2-wk period in a 4 x 4 latin square design with 3 replicates. each year, the experiment lasted 8 wk. swards were in a vegetative stage throughout the experiment. herbage constituents were determined, and dm intake was ...200616899684
importance of host plant species, neotyphodium endophyte isolate, and alkaloids on feeding by spodoptera frugiperda (lepidoptera: noctuidae) larvae.three grass host species--tall fescue, festuca arundinacea schreber; meadow fescue, festuca pratensis hudson; and perennial ryegrass, lolium perenne l.--each infected with a number of different neotyphodium endophyte isolates, were investigated for their effects on fall armyworm, spodoptera frugiperda (j.e. smith). alkaloid profiles varied among associations. choice and no-choice tests comparing feeding and early development of s. frugiperda larvae on endophyte-infected and endophyte-free leaf b ...200616937705
protein interactions of mads box transcription factors involved in flowering in lolium perenne.regulation of flowering time is best understood in the dicot model species arabidopsis thaliana. molecular analyses revealed that genes belonging to the mads box transcription factor family play pivotal regulatory roles in both the vernalization- and photoperiod-regulated flowering pathways. here the analysis of three apetala1 (ap1)-like mads box proteins (lpmads1-3) and a short vegetative phase (svp)-like mads box protein (lpmads10) from the monocot perennial grass species lolium perenne is rep ...200617005923
perennial ryegrass (lolium perenne l.).a protocol that facilitates rapid establishment of agrobacterium-mediated transformation for perennial ryegrass is described. the synthetic green fluorescent protein (sgfps65t) reporter gene is introduced in combination with the nptii selectable marker gene into axillary bud derived embryogenic calli of perennial ryegrass (lolium perenne l.) by co-cultivation with agrobacterium tumefaciens strain agl0 harboring binary vector pyf132. following the co-cultivation calli are cultured for 48 h in liq ...200617033051
a p67phox-like regulator is recruited to control hyphal branching in a fungal-grass mutualistic symbiosis.key requirements for microbes to initiate and establish mutualistic symbiotic interactions with plants are evasion of potential host defense responses and strict control of microbial growth. reactive oxygen species (ros) produced by a specific nadph oxidase isoform, noxa, regulate hyphal growth in the mutualistic interaction between the fungal endophyte epichloë festucae and its grass host lolium perenne. unlike mammalian systems, little is known about the fungal nadph oxidase complex and its re ...200617041146
breeding for disease resistance in the major cool-season turfgrasses.over the past several decades, breeding cool-season turfgrasses for improved disease resistance has been the focus of many turfgrass breeding programs. this review article discusses the dramatic improvements made in breeding kentucky bluegrass (poa pratensis) for resistance to leaf spot (caused by drechslera poae), stem rust (caused by puccinia graminis), and stripe smut (caused by ustilago striiformis); perennial ryegrass (lolium perenne) for resistance to gray leaf spot (caused by pyricularia ...200617061916
phosphorus nutrition and mycorrhiza effects on grass leaf growth. p status- and size-mediated effects on growth zone kinematics.this study tested whether leaf elongation rate (ler, mm h(-1)) and its components--average relative elemental growth rate (regravg, mm mm(-1) h(-1)) and leaf growth zone length (l(lgz), mm)--are related to phosphorus (p) concentration in the growth zone (p(lgz) mg p g(-1) tissue water) of lolium perenne l. cv. condesa and whether such relationships are modified by the arbuscular mycorrhizal fungus (amf) glomus hoi. mycorrhizal and non-mycorrhizal plants were grown at a range of p supply rates an ...200617080603
arbuscular mycorrhizal colonization on carbon economy in perennial ryegrass: quantification by 13co2/12co2 steady-state labelling and gas exchange.effects of the arbuscular mycorrhizal fungus (amf) glomus hoi on the carbon economy of perennial ryegrass (lolium perenne) were investigated by comparing nonmycorrhizal and mycorrhizal plants of the same size, morphology and phosphorus status. plants were grown in the presence of co2 sources with different c isotope composition (delta13c -1 or -44). relative respiration and gross photosynthesis rates, and belowground allocation of c assimilated during one light period ('new c'), as well as its c ...200617083684
characterization of contamination in and toxicities of a shipyard area in hong kong.this is the first integrated study on the contaminant characterization and toxicities of a shipyard area. this site in hong kong contained 3.6-33.4 mg kg(-1) dichlorodiphenyltrichloroethane and 5-79 g kg(-1) oil and grease. other pollutants exceeding the dutch intervention values were total polyaromatic hydrocarbons, total petroleum hydrocarbons, and metals cu, pb and zn. these pollutants persisted partially owing to the poor fertility with <125 mg n kg(-1) and <530 mg p kg(-1) typical of coasta ...200616360247
the effects of birdsfoot trefoil (lotus corniculatus) and chicory (cichorium intybus) when compared with perennial ryegrass (lolium perenne) on ovine gastrointestinal parasite development, survival and migration.two experiments were conducted to investigate the effects of birdsfoot trefoil and chicory on parasitic nematode development, survival and migration when compared with perennial ryegrass. in experiment one, sheep faeces, containing 10,385 cooperia curticei eggs were added to 25 cm diameter pots containing birdsfoot trefoil, chicory or ryegrass, and the pots maintained under optimal conditions for nematode parasite development. replicate pots of each forage type were destructively sampled on day ...200616495015
effects of legume forages on ovine gastrointestinal parasite development, migration and survival.lambs grazing certain legumes have reduced parasite intensities compared to lambs grazing ryegrass swards. eighteen replicates of white clover (cv. aberherald), lucerne (cv. luzelle), red clover (cv. merviot) and perennial ryegrass (cv. abersilo) were sown at equivalent field rates in 25 cm diameter pvc pots and maintained outside for 6 months. on day 0, forage in each pot was cut to 50 mm from soil level and the pots were placed in a glasshouse (at 19-25 degrees c and 70% humidity) in a randomi ...200616516388
reactive oxygen species play a role in regulating a fungus-perennial ryegrass mutualistic interaction.although much is known about the signals and mechanisms that lead to pathogenic interactions between plants and fungi, comparatively little is known about fungus-plant mutualistic symbioses. we describe a novel role for reactive oxygen species (ros) in regulating the mutualistic interaction between a clavicipitaceous fungal endophyte, epichloë festucae, and its grass host, lolium perenne. in wild-type associations, e. festucae grows systemically in intercellular spaces of leaves as infrequently ...200616517760
a high throughput agrobacterium tumefaciens-mediated transformation method for functional genomics of perennial ryegrass (lolium perenne l.).a robust and high throughput agrobacterium genetic transformation procedure has been developed for perennial ryegrass (lolium perenne l.). embryogenic callus lines were selected and maintained as plants in vitro. embryogenic calli derived from meristematic regions of the vegetative tillers were co-cultivated with agrobacterium tumefaciens strain eha101 carrying the plasmid pcambia 1305.1 in the presence of acetosyringone for 3-4 days. the calli were grown under 94.8 and 151.6 microm hygromycin s ...200616518636
effects of amount of intake and stage of forage maturity on urinary allantoin excretion and estimated microbial crude protein synthesis in the rumen of steers.using ruminally cannulated steers, we investigated how urinary allantoin excretion was related to variations in feed intake and stage of forage maturity. further, different approaches were compared for predicting ruminal microbial crude protein (mcp) synthesis and its efficiency. experimental diets were arranged in a replicated 3 x 3 latin square design (experiment 1) and a 4 x 4 latin square design (experiment 2). in experiment 1, a mixed diet [forage to concentrate, 68:32 on a dry matter (dm) ...200616519758
an easy and rapid method using microscopy to determine herbicide effects in poaceae weed species.a new, easy, rapid and relatively inexpensive method using microscopy has been developed for the detection of herbicide effects in leaves of grass weed species displaying no visual signs of damage. the method has potential to be used as a tool to indicate future death of grass species due to herbicide exposure by observing phytochemical effects, i.e. early-warning effects. in the present study, apera spica-venti (l.) beauv., bromus hordeaceus l., alopecurus myosuroides huds., lolium perenne l. a ...200616628541
intake and performance of lactating cows grazing diverse forage mixtures.twenty multiparous holstein cows in midlactation grazed pastures of 4 forage mixtures in a 12-wk study repeated during 2 grazing seasons to determine if forage mixture complexity affected intake and productivity of lactating dairy cows. the forage mixtures were 1) orchardgrass plus white clover [2 species (sp)]; 2) orchardgrass, white clover, and chicory (3sp); 3) orchardgrass, tall fescue, perennial ryegrass, red clover, birdsfoot trefoil, and chicory (6sp); and 4) 6sp mixture plus white clover ...200616702282
fungal plant endosymbionts alter life history and reproductive success of aphid predators.endosymbionts occur in most plant species and may affect interactions among herbivores and their predators through the production of toxic alkaloids. here, we ask whether effects of mycotoxins produced by the symbiosis of the fungal endophyte neotyphodium lolii and the grass lolium perenne are transmitted to the aphidophagous ladybird coccinella septempunctata when feeding on cereal aphids rhopalosiphum padi on infected plants. the larval development of coccinellids was extended, while their sur ...200616720406
the effect of chicory ( cichorium intybus ) and sulla ( hedysarum coronarium ) on larval development and mucosal cell responses of growing lambs challenged with teladorsagia circumcincta.the aim of this study was to investigate the effects of grazing different bioactive forages on acquired immunity against teladorsagia circumcinta infection. the development of immunity was assessed by following the response of trickle-infected lambs grazing chicory (cichorium intybus; ic), sulla (hedysarum coronarium; is) or grass/clover (lolium perenne/trifolium repens; igc), to a single challenge infection. parasite-naive lambs, grazing grass/clover, were also challenged with the single infect ...200616332288
quantification of pollen solute release using pollen grain column chromatography.the impact of pollen on the respiratory mucosa was modeled by studying the process by which solutes are eluted from pollen grains. rye grass (lolium perenne), short ragweed (ambrosia artemisiifolia), and white oak (quercus alba) pollens were packed between glass wool plugs in small columns. water was pumped through the columns and the eluate solute yield was determined by measurement of the dry solute weight. solute separation was rapid, and concentrations and osmolalities of the eluate decrease ...20061456413
molecular and functional characterization of a cdna encoding fructan:fructan 6g-fructosyltransferase (6g-fft)/fructan:fructan 1-fructosyltransferase (1-fft) from perennial ryegrass (lolium perenne l.).fructans are the main storage compound in lolium perenne. to account for the prevailing neokestose-based fructan synthesis in this species, a cdna library of l. perenne was screened by using the onion (allium cepa) fructan:fructan 6g-fructosyltransferase (6g-fft) as a probe. a full length lp6g-fft clone was isolated with significant homologies to vacuolar type fructosyltransferases and invertases. the functionality of the cdna was tested by heterologous expression in pichia pastoris. the recombi ...200616840511
quantitative trait loci controlling vernalisation requirement, heading time and number of panicles in meadow fescue (festuca pratensis huds.).the "bf14/16xhf2/7" mapping population of meadow fescue (festuca pratensis huds.) was characterised for number of panicles produced by non-vernalised plants in the field, vernalisation requirement (number of weeks at 6 degrees c and 8 h photoperiod), as well as days to heading, number of panicles and proportion of shoots heading after a 12 weeks vernalisation treatment. quantitative trait loci (qtls) were identified and compared to qtls and genes related to the induction of flowering in cereals ...200616235049
joint action of benzoxazinone derivatives and phenolic acids.the joint action of binary and ternary mixtures of benzoxazinone derivatives and phenolic acids was studied using the additive dose model (adm) as reference model. the activity of fixed-ratio mixtures of phenolic acids [ferulic acid (fa), p-coumaric acid (ca), vanillic acid (va), and p-hydroxybenzoic acid (hba)] and benzoxazinone derivatives [2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (dimboa), 6-methoxybenzoxazolin-2-one (mboa), benzoxazolin-2-one (boa), 2-aminophenol (ap), and n-(2-hydroxyph ...200616478216
effect of sheep urine deposition on the bacterial community structure in an acidic upland grassland soil.the effect of the addition of synthetic sheep urine (ssu) and plant species on the bacterial community composition of upland acidic grasslands was studied using a microcosm approach. low, medium, and high concentrations of ssu were applied to pots containing plant species typical of both unimproved (agrostis capillaris) and agriculturally improved (lolium perenne) grasslands, and harvests were carried out 10 days and 50 days after the addition of ssu. ssu application significantly increased both ...200617088382
effects of the fungal endophyte, neotyphodium lolii, on net photosynthesis and growth rates of perennial ryegrass (lolium perenne) are independent of in planta endophyte concentration.neotyphodium lolii is a fungal endophyte of perennial ryegrass (lolium perenne), improving grass fitness through production of bioactive alkaloids. neotyphodium species can also affect growth and physiology of their host grasses (family poaceae, sub-family pooideae), but little is known about the mechanisms. this study examined the effect of n. lolii on net photosynthesis (p(n)) and growth rates in ryegrass genotypes differing in endophyte concentration in all leaf tissues.200616735403
host preference of the chinch bug, blissus occiduus.the chinch bug, blissus occiduus barber (hemiptera: blissidae), is an important pest of buffalograss, buchloë dactyloides (nutall) engelmann and potentially other turfgrass, crop, and non-crop hosts. choice studies documented the number of b. occiduus present on selected turfgrasses, crops and weeds, and provided important insights into the host preferences of this chinch bug. grasses with the most chinch bugs present included the warm-season turfgrasses b. dactyloides , zoysiagrass, zoysia japo ...200619537992
magnaporthe oryzae isolates causing gray leaf spot of perennial ryegrass possess a functional copy of the avr1-co39 avirulence gene.summary gray leaf spot of perennial ryegrass (lolium perenne) is a severe foliar disease caused by the ascomycete fungus magnaporthe oryzae (formerly known as magnaporthe grisea). control of gray leaf spot is completely dependent on the use of fungicides because currently available perennial ryegrass cultivars lack genetic resistance to this disease. m. oryzae isolates from perennial ryegrass (prg) were unable to cause disease on rice cultivars co39 and 51583, and instead triggered a hypersensit ...200620507436
stem rust of small grains and grasses caused by puccinia graminis.summary stem rust has been a serious disease of wheat, barley, oat and rye, as well as various important grasses including timothy, tall fescue and perennial ryegrass. the stem rust fungus, puccinia graminis, is functionally an obligate biotroph. although the fungus can be cultured with difficulty on artificial media, cultures grow slowly and upon subculturing they develop abnormal ploidy levels and lose their ability to infect host plants [bushnell and bosacker (1982) can. j. bot. 60, 1827-1836 ...200520565642
telomere hypervariability in magnaporthe oryzae.summary the gray leaf spot disease of perennial ryegrass and tall fescue is caused by the fungus magnaporthe oryzae (anamorph = pyricularia oryzae). a collection of single-copy and repetitive dna markers was used to investigate genetic diversity among 22 isolates of the gray leaf spot pathogen. the single-copy dna markers revealed only three polymorphisms among 95 restriction fragments spanning approximately 0.6% of the genome. in addition, southern hybridization analysis and mating tests reveal ...200520565657
genetic structure of magnaporthe grisea populations associated with st. augustinegrass and tall fescue in georgia.abstract amplified fragment length polymorphisms (aflps) were used to estimate phylogenetic relationships within magnaporthe grisea and determine the genetic structure of m. grisea populations associated with tall fescue and st. augustinegrass in georgia. sixteen clonal lineages were identified in a sample population of 948 isolates. five lineages were isolated from tall fescue (e, g1, g2, g4, and h), with lineage g4 comprising 90% of the population. isolates from tall fescue were closely relate ...200518943310
prevalence and clinical relevance of specific immunoglobulin e to pollen caused by sting- induced specific immunoglobulin e to cross-reacting carbohydrate determinants in hymenoptera venoms.hymenoptera stings can induce specific ige (sige) to carbohydrate determinants (cd) on venom glycoproteins that cross-react with cd in pollen. sige to such cross-reacting cd (ccd) are believed to have little or no biological activity and thus may cause misdiagnosis of pollen sensitization after a sting.200515836751
[allelopathic effects of invasive weed solidago canadensis on native plants].with growth chamber method, this paper studied the allelopathic potential of invasive weed solidago canadensis on native plant species. different concentration s. canadensis root and rhizome extracts were examined, and the test plants were trifolium repens, trifolium pretense, medicago lupulina, lolium perenne, suaeda glauca, plantago virginica, kummerowia stipulacea, festuca arundinacea, ageratum conyzoides, portulaca oleracea, and amaranthus spinosus. the results showed that the allelopathic i ...200516515192
the fatty acid composition of muscle fat and subcutaneous adipose tissue of pasture-fed beef heifers: influence of the duration of grazing.our objective was to determine the effect of the duration of grazing before slaughter on the fatty acid composition of muscle fat and s.c. adipose tissue (sat) of beef heifers. sixty crossbred charolais heifers (n = 15 per treatment) were assigned randomly to one of four dietary treatments: 45 animals (treatments 1, 2, and 3, respectively) were housed at the beginning of the experiment, and 15 (treatment 4) were fed at pasture. two groups of 15 heifers were moved to pasture 40 d (treatment 2) an ...200515827261
soil to plant transfer of 238u, 226ra and 232th on a uranium mining-impacted soil from southeastern china.both soil and plant samples of nine different plant species grown in soils from southeastern china contaminated with uranium mine tailings were analyzed for the plant uptake and translocation of 238u, 226ra and 232th. substantial differences were observed in the soil-plant transfer factor (tf) among these radionuclides and plant species. lupine (lupinus albus) exhibited the highest uptake of 238u (tf value of 3.7x10(-2)), while chinese mustard (brassica chinensis) had the least (0.5x10(-2)). how ...200515878419
fungal endophyte n-acetylglucosaminidase expression in the infected host grass.fungal endophytes of the genera neotyphodium and epichlolë are important mutualistic symbionts and pathogens of many cool-season grass species. here we report the characterization of a secreted n-acetylglucosaminidase from the neotyphodium sp. endophyte that infects the grass poa ampla. the enzyme was expressed at low levels within the host, and activity could be detected in the apoplastic protein fraction. low-level expression could also be detected in endophyte-infected perennial ryegrass (lol ...200515912954
comparison of early development of three grasses: lolium perenne, agrostis stolonifera and poa pratensis.to improve the management of grass communities, early plant development was compared in three species with contrasting growth forms, a caespitose (lolium perenne), a rhizomatous (poa pratensis) and a caespitose-stoloniferous species (agrostis stolonifera).200515932884
effect of forage legumes and anthelmintic treatment on the performance, nutritional status and nematode parasites of grazing lambs.recent studies in new zealand and the uk have shown that certain forages reduce parasitic infection in sheep. the aim of this experiment was to investigate the effects of legume forages compared to ryegrass on interactions between production, nutritional status and nematodes in grazing lambs. twenty-four male lambs per forage treatment, half of which were treated with anthelmintics on day 0, grazed monocultures of lucerne (medicago sativa), red clover (trifolium pratense) and white clover (trifo ...200515946801
molecular cloning and genetic analysis of a symbiosis-expressed gene cluster for lolitrem biosynthesis from a mutualistic endophyte of perennial ryegrass.lolitrems are potent tremorgenic mycotoxins that are synthesised by clavicipitaceous fungal endophytes of the epichloë/neotyphodium group in association with grasses. these indole-diterpenes confer major ecological benefits on the grass-endophyte symbiotum. a molecular signature for diterpene biosynthesis is the presence of two geranylgeranyl diphosphate (ggpp) synthases. using degenerate primers for conserved domains of fungal ggpp synthases, we cloned two such genes, ltmg and ggsa, from neotyp ...200515991026
a symbiosis expressed non-ribosomal peptide synthetase from a mutualistic fungal endophyte of perennial ryegrass confers protection to the symbiotum from insect herbivory.while much is known about the biosynthesis of secondary metabolites by filamentous fungi their biological role is often less clear. the assumption is these pathways have adaptive value to the organism but often the evidence to support this role is lacking. we provide the first genetic evidence that the fungal produced secondary metabolite, peramine, protects a host plant from insect herbivory. peramine is a potent insect feeding deterrent synthesized by epichloë/neotyphodium mutualistic endophyt ...200516091042
fatty acid profiles associated with microbial colonization of freshly ingested grass and rumen biohydrogenation.two in situ studies were conducted to examine the use of odd-chain fatty acid profiles to study microbial colonization of freshly ingested herbage in the rumen as well as fatty acid biohydrogenation. in the first study, fresh perennial ryegrass was subjected to a range of sample preparation methods before incubation in the rumen for 2 or 7 h. in the second study, fresh perennial ryegrass was chopped into 1-cm lengths and incubated in polyester bags in the rumen for 2, 8, and 24 h. after removal ...200516107412
effects of perennial ryegrass cultivars on intake, digestibility, and milk yield in dairy cows.the effects of 8 diploid perennial ryegrass (lolium perenne l.) cultivars on dry matter (dm) intake, dm digestibility, and milk yield (my) of dairy cows were evaluated in the summer of 2000 and 2001. each summer, herbage was harvested daily and stall-fed to 12 dairy cows during six 2-wk periods. six cultivars were fed in 3 periods (1, 3, and 5) according to a double 3 x 3 latin square design. in the other periods (2, 4, and 6), 2 cultivars were fed in a repeated measurement design. herbage mass ...200516107414
[effects of simulated nitrogen deposition on weeds growth and nitrogen uptake].in this paper, a greenhouse experiment was conducted to study the responses of different functional groups weeds to simulated nitrogen deposition (4.0 g n.m(-2).yr(-1)). native weed species poa annua, lolium perenne, avena fatua, medicago lupulina, trifolium repens, plantago virginica, veronica didyma, echinochloa crusgalli var. mitis, eleusine indica and amaranthus spinosus in orchard ecosystem were used test materials, and their above-and underground biomass and nitrogen uptake were measured. ...200516110678
four qtls determine crown rust (puccinia coronata f. sp. lolii) resistance in a perennial ryegrass (lolium perenne) population.crown rust resistance is an important selection criterion in ryegrass breeding. the disease, caused by the biotrophic fungus puccinia coronata, causes yield losses and reduced quality. in this study, we used linkage mapping and qtl analysis to unravel the genomic organization of crown rust resistance in a lolium perenne population. the progeny of a pair cross between a susceptible and a resistant plant were analysed for crown rust resistance. a linkage map, consisting of 227 loci (aflp, ssr, rfl ...200516118663
qtl mapping of resistance to gray leaf spot in ryegrass.gray leaf spot (gls) is a serious fungal disease caused by magnaporthe grisea, recently reported on perennial ryegrass (lolium perenne l.), an important turf grass and forage species. this fungus also causes rice blast and many other grass diseases. rice blast is usually controlled by host resistance, but durability of resistance is a problem. little gls resistance has been reported in perennial ryegrass. however, greenhouse inoculations in our lab using one ryegrass isolate and one rice-infecti ...200516133316
effects of cadmium in herbage on the apparent absorption of elements by sheep in comparison with inorganic cadmium added to their diet.a meta-analysis of existing scientific literature recently suggested that cd is absorbed more efficiently by sheep if it is in the organic form in grass, than if it is added as an inorganic supplement to the diet. we tested this experimentally by feeding sheep grass from contaminated soil, compared with uncontaminated grass and with cd added to the diet. to produce contaminated herbage, cd nitrate was added to soil in 11 lysimeters sown with perennial ryegrass, with a further 11 lysimeters recei ...200516194672
phosphorus nutrition-mediated effects of arbuscular mycorrhiza on leaf morphology and carbon allocation in perennial ryegrass.the aim of this work was to disentangle phosphorus status-dependent and -independent effects of arbuscular mycorrhizal fungus (amf) on leaf morphology and carbon allocation in perennial ryegrass (lolium perenne). to this end, we assessed the p-response function of morphological components in mycorrhizal and nonmycorrhizal plants of similar size. amf (glomus hoi) stimulated relative p-uptake rate, decreased leaf mass per area (lma), and increased shoot mass ratio at low p supply. lower lma was ca ...200516219082
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