Season Grasses Research Articles

Do Botanophila flies provide reproductive isolation between two species of Epichloë fungi? A field test

Epichloë spp., fungal endophytes of cool season grasses, produce collars of mycelium (stromata) on host stems that Botanophila flies visit for egg laying. Flies transfer fungal gametes among stromata and thereby serve to cross-fertilize fungi. Hence, the interaction is analogous to insect pollination in angiosperms. While most Epichloë species are not interfertile, Epichloë typhina and Epichloë clarkii can hybridize. We investigated whether Botanophila flies play a role in the reproductive isolation of the two Epichloë species at a field site in southwestern Switzerland. We estimated the density of stromata and collected fly larvae and stromata occurring on plants. While most ascospores collected from both species indicated intraspecific mating, 9.3% of fungal fruiting bodies contained spores of hybrid origin. Two species of Botanophila larvae occurred on stromata and both preferred E. typhina. Yet, both fly species laid eggs on both fungal species. While preferences by Botanophila flies should influence reproductive isolation between the fungi, other mechanisms are likely more important. Our data, which show hybrid ascospores are produced, suggest postzygotic isolating mechanisms are an important means of reproductive isolation.

Difference in symptom severity between early and late grass pollen season in patients with seasonal allergic rhinitis

BackgroundFor the development of forecasts for seasonal allergic rhinitis symptoms, it is essential to understand the relationship between grass pollen concentrations and the symptoms of grass pollen allergic patients.ObjectiveThe aim of this study was to delineate this relationship between seasonal allergic rhinitis symptoms and grass pollen concentrations in the Netherlands.MethodsGrass pollen allergic patients (n = 80 [2007] - 84 [2008]) were enrolled into the study. They were asked to enter their seasonal allergic rhinitis symptoms (runny nose, sneezing, blocked nose, post nasal drip, and eye symptoms) daily on a scale from 0 to 3 to the study centre either by short message service (SMS) or by internet from May-July 2007 and April-July 2008. Daily pollen counts were used to define the early and the late grass pollen season as the period 'before and during' respectively 'after' the first grass pollen peak (more than 150 pollen/m3).ResultsAt similar grass pollen concentrations, the daily mean of the individual maximum symptom scores reported in the early season were higher as compared to that reported in the late season [differences of -0.41 (2007) and -0.30 (2008)]. This difference could not be explained by medication use by the patients nor by co-sensitization to birch.ConclusionsWe conclude that seasonal allergic rhinitis symptoms at similar grass pollen concentrations are more severe in the early flowering season as compared to those in the late flowering season. This finding is not only relevant for development of forecasts for seasonal allergic rhinitis symptoms but also for understanding symptom development and planning and analysis of clinical studies.

Potentiality of Four Cool Season Grasses and Miscanthus sinensis for Feedstock in the Cool Regions of Japan

It is planned to increase plant biomass feedstock to sustain the renewable energy source, bioenergy. In cool regions such as Hokkaido which often offers a short and stressful growth season, less is known about biomass potential (BP) in plants, and generally there is a lack of data regarding a regional suitable harvesting system in feedstock. A constant supply of feedstock per month using several biomass plants would be important for establishing an all year round operating system (AYROS) in biofuel production. Two types of perennial lignocellulosic crops, four C3 grasses which adapt well to cool environments, orchardgrass (OG), reed canarygrass (RC), tall fescue (TF) and timothy (TI), referred to as cool season grasses (CSG) and C4 native grass, Miscanthus sinensis called 'susuki', were evaluated for the BP in Sapporo, Japan. CSG were sown into fertilized land in 2006, whilst M. sinensis was planted in 2007 without fertilization. Three years after planting, in 2009, regional potential across all harvesting of CSG was 9.7 t ha-1 year-1. Different harvestings of CSG revealed high BP from RC and TI rather than OG and TF. RC showed BP peaks twice, in June (11±0.45 t ha-1 year-1) and September (15±1.11 t ha-1 year-1), and a single peak in July (15±1.99 t ha-1 year-1) for TI, indicating that RC is a two peaks type, whilst TI falls into a one peak type. For M. sinensis, the BP increased with the year and varied among accessions. In 2009, regional potential was 1,287±343 g plant-1 year-1. Accessions native to Hokkaido showed maximum BP of 827±353 g plant-1 year-1, mainly from Matsumae (1,622±692 g plant-1 year-1) and Toyoura (2,174±169 g plant-1 year-1). Accessions native to areas other than Hokkaido yielded a potential of 2,206±388 g plant-1 year-1, mainly from Shiozuka (2,531±526 g plant-1 year-1) and Akeno (2,653±635 g plant-1 year-1), substantially higher than the BP of Hokkaido accessions. The BP of M. sinensis over two years of 9 accessions in the present study was about 36.9 t ha-1 year-1, by converting biomass data of plant (921.4 g plant-1 year-1) to land area unit. The BP experiment estimates biomass feedstock is supplied with 10-15 t ha-1 by harvesting TI and RC in June to September and 30 t ha-1 by harvesting M. sinensis in October. This study demonstrated the feasibility and advantage of the combination of CSG and M. sinensis. The BP could be improved using mostly superior genotypes of M. sinensis selected from areas other than Hokkaido. The information from the present study will be available for establishing AYROS in feedstock production for biofuels such as bioethanol in cool regions such as Hokkaido.

First report of dollar spot of Agrostis stolonifera, Poa pratensis, Festuca arundinacea and Zoysia japonica caused by Sclerotinia homoeocarpa in China

Sclerotinia homoeocarpa causes dollar spot disease on many warm and cool season grasses. In Asia, this disease has only been formally reported in Japan (Hsiang & Mahuku, 1999) and south China (Lv et al., 2010). In China, the first anecdotal reports of dollar spot disease on turf were from the late 1990s, mainly in south China. For the past few years, this disease has been observed on cool season turfgrasses in north China with increasing severity. Outbreaks at golf courses in Beijing were observed in 2008, 2009 and 2010, where disease was first seen in early spring and developed from late spring until temperatures exceeded 32°C in early summer. When temperatures dropped below this in late summer, the disease flared up again until mid-autumn. Maximum disease development usually occurred on turf deficient in nitrogen and water, especially with warm days and cool nights with heavy dew.Characteristic hourglass foliar lesions were at first chlorotic, and then appeared water-soaked and finally bleached, with typical reddish-brown borders. Small patches appeared on turfgrasses, with a typical incidence of patches of 1-5/m2 and up to 50/m2 under high disease levels. In late May 2009, disease samples were collected from several golf courses in Beijing, and fungal isolates obtained from creeping bentgrass (Agrostis stolonifera), Kentucky bluegrass (Poa pratensis), tall fescue (Festuca arundinacea) and zoysia grass (Zoysia japonica). On potato dextrose agar (PDA) medium, white fluffy mycelia covered the whole petri dish three days after incubation, and formed brown columnar structures in the centres by seven days. Cultures more than 14 days old became cinnamon coloured and formed dark brown or black substratal stroma. Four-week-old seedlings of A. stolonifera cv. T-1, P. pratensis cv. Nu-Glade, F. arundinacea cv. Arid 3 and Z. japonica cv. Lanyin No. 3 were inoculated with 5-mm-diameter mycelial plugs of respective isolates of the fungus from five-day-old PDA cultures, by placing plugs onto the leaves and incubating under humid conditions. White aerial hyphae and leaf lesions were observed within seven days after inoculation on all four species of turfgrass, but no disease was seen with sterile agar plugs as inoculum. The fungus was re-isolated from lesions to satisfy Koch's postulates. DNA from one isolate per host species was amplified with internal transcribed spacer (ITS) primers and sequenced to yield 610 bp fragments (GenBank Accession Nos. GQ924923-GQ924926). Sequences were analysed by BLAST against GenBank, and showed over 99% identity with ITS regions of sequences identified as S. homoeocarpa. To the best of our knowledge, this is the first formal report of dollar spot disease on creeping bentgrass, Kentucky bluegrass, tall fescue or zoysia grass in China.

Public Perception and Sustainable Management Strategies for Roadside Vegetation

Sustainable management strategies for roadside vegetation limit the amount of nonnative turf grass and include masses of native shrubs and trees and meadows of native, warm season grasses, flowering perennials, or both. Sustainably managed roadsides can contribute to a matrix of economically conservative, environmentally responsible, and aesthetically pleasing landscapes. Implementation of sustainable strategies may result in cost savings, better water quality and hydraulic conductivity, improved safety measures, increased biodiversity, benefits to the socioeconomic health of the state, and adherence to state and federal policy. Sustainable strategies provide optimal cost savings and enhancement of environmental stewardship only when implemented consistently. Aesthetically, sustainable landscapes often represent a departure from the traditional expectation of how a roadside landscape should appear. Lacking an awareness of the inherent values present in sustainably managed roadsides, the public is often hesitant to accept this atypical and often less-manicured aesthetic; the public reaction causes many departments of transportation (DOTs) to revert to traditional management regimes. Many state DOTs maintain active ties to the public and political communities of their state and acquiesce to the wishes of these communities when appropriate. Because they are often called on to defend their design, management, and operating procedures, DOTs have a new role in raising awareness, assessing perception, and informing the public about the benefits associated with management strategies for sustainable roadside vegetation. This paper examines the evolution of the roadside landscape and various approaches to vegetation management from the birth of the road network to today's strategies, which include benchmarks for sustainability.

Forage as a primary source of mycotoxins in animal diets.

The issue of moulds and, thus, contamination with mycotoxins is very topical, particularly in connexion with forages from grass stands used at the end of the growing season. Deoxynivalenol (DON), zearalenone (ZEA), fumonisins (FUM) and aflatoxins (AFL) are among the most common mycotoxins. The aim of the paper was to determine concentrations of mycotoxins in selected grasses (Lolium perenne, Festulolium pabulare, Festulolium braunii) and their mixtures with Festuca rubra an/or Poa pratensis during the growing season as a marker of grass safety, which was assessed according to content of the aforementioned mycotoxins. During the growing season grass forage was contaminated with mycotoxins, most of all by DON and ZEA. The contents of AFL and FUM were zero or below the limit of quantification. Moreover, the level of the occurrence of mould was quantified as ergosterol content, which was higher at the specific date of cut. All results were statistically processed and significant changes were discussed.

Restoration of Native Warm Season Grassland Species in a Tall Fescue Pasture Using Prescribed Fire and Herbicides

Pastures dominated by tall fescue (Schedonorus phoenix (Scop.) Holub) cover much of the eastern United States, and there are increasing efforts to restore native grassland plant species to some of these areas. Prescribed fire and herbicide are frequently used to limit the growth of tall fescue and other non‐natives, while encouraging native grasses and forbs. A fungal endophyte, commonly present in tall fescue, can confer competitive advantages to the host plant, and may play a role in determining the ability of tall fescue plants to persist in pastures following restoration practices. We compared vegetation composition among four actively restored subunits of a tall fescue pasture (each receiving different combinations of prescribed fire and/or herbicide) and a control. We also measured the rate of endophyte infection in tall fescue present within each restoration treatment and control to determine if restoration resulted in lower tall fescue cover but higher endophyte infection rates (i.e. selected for endophyte‐infected individuals). Tall fescue cover was low in all restoration treatments and the control (1.1–17.9%). The control (unmanaged) had higher species richness than restoration treatments and plant community composition was indicative of succession to forest. Restoration practices resulted in higher cover of native warm season grasses, but in some cases also promoted a different undesirable species. We found no evidence of higher fungal endophyte presence in tall fescue following restoration, as all subunits had low endophyte infection rates (2.2–9.3%). Restoration of tall fescue systems using prescribed fire and herbicide may be used to promote native grassland species.

Laryngeal effects of nasal allergen provocation in singers with allergic rhinitis

In spite of our recent insight into nasobronchial interaction mechanisms in allergic airway disease, the association between allergic rhinitis and voice complaints remains obscure. To evaluate the effects of nasal allergen provocation and seasonal grass pollen exposure on subjective and objective laryngeal parameters in singers with and without allergic rhinitis, an observational case control study was conducted. Prior to the pollen season, six grass pollen allergic and six non-allergic semiprofessional singers were exposed to nebulized sham solution and grass pollen extract (HAL°) in rising concentrations. After 3 min, 60 min and 24 h, nasal and laryngeal complaints were evaluated by the use of a visual analog scale (VAS). Laryngeal parameters like voice appearance (video stroboscopic images), voice range profile and subjective (GRBAS) and objective (jitter, shimmer, H/N, DSI) voice quality were evaluated before provocation, after 60 min and 24 h. During the pollen season, the allergic singers were re-evaluated. Results showed that in allergic singers both nasal (TNS of 4.0 ± 2.4 vs. 0.0 ± 0.0, p < 0.05) and laryngeal complaints (TLS of 1.4 ± 1.1 vs. 0.0 ± 0.2, p < 0.05) were induced at 3 min after the provocation. The induced laryngeal complaints were the feeling of laryngeal irritation, secretions and globus. No change in voice quality or stroboscopy score was measured. During the pollen season, laryngeal complaints were present (TLS of 2.4 ± 2.4) in allergic singers, without evidence for objective voice and laryngeal changes. In conclusion, we here demonstrate the rapid induction of laryngeal complaints in allergic singers by nasal allergen provocation and during the pollen season. There was no subject reported or investigator measured change in voice quality. No change in stroboscopy score was measured.

Landscape-scale feeding patterns of African elephant inferred from carbon isotope analysis of feces

The African elephant (Loxodonta africana) is a large-bodied, generalist herbivore that eats both browse and grass. The proportions of browse and grass consumed are largely expected to reflect the relative availability of these resources. We investigated variations in browse (C(3) biomass) and grass (C(4)) intake of the African elephant across seasons and habitats by stable carbon isotope analysis of elephant feces collected from Kruger National Park, South Africa. The results reflect a shift in diet from higher C(4) grass intake during wet season months to more C(3) browse-dominated diets in the dry season. Seasonal trends were correlated with changes in rainfall and with nitrogen (%N) content of available grasses, supporting predictions that grass is favored when its availability and nutritional value increase. However, switches to dry season browsing were significantly smaller in woodland and grassland habitats where tree communities are dominated by mopane (Colophospermum mopane), suggesting that grasses were favored here even in the dry season. Regional differences in diet did not reflect differences in grass biomass, tree density, or canopy cover. There was a consistent relationship between %C(4) intake and tree species diversity, implying that extensive browsing is avoided in habitats characterized by low tree species diversity and strong dominance patterns, i.e., mopane-dominated habitats. Although mopane is known to be a preferred species, maintaining dietary diversity appears to be a constraint to elephants, which they can overcome by supplementing their diets with less abundant resources (dry season grass). Such variations in feeding behavior likely influence the degree of impact on plant communities and can therefore provide key information for managing elephants over large, spatially diverse, areas.

Fructan accumulation and transcription of candidate genes during cold acclimation in three varieties of Poa pratensis

Poa pratensis, a type species for the grass family ( Poaceae), is an important cool season grass that accumulates fructans as a polysaccharide reserve. We studied fructan contents and expression of candidate fructan metabolism genes during cold acclimation in three varieties of P. pratensis adapted to different environments: Northern Norway, Denmark, and the Netherlands. Fructan content increased significantly during cold acclimation and varieties showed significant differences in the level of fructan accumulation. cDNA sequences of putative fructosyltransferase ( FT), fructan exohydrolase ( FEH), and cold acclimation protein ( CAP) genes were identified and cloned. In agreement with a function in fructan biosynthesis, transcription of a putative sucrose:fructan 6-fructosyltransferase ( Pp6-SFT) gene was induced during cold acclimation and fructan accumulation in all three P. pratensis varieties. Transcription of putative PpFEH and PpCAP genes was also induced by cold acclimation; however, transcription of these two genes was several-fold higher in the variety from Norway compared to the other two varieties. The results presented here suggest that Pp6-SFT is involved in fructan biosynthesis in P. pratensis. FEHs have previously been suggested to be involved in fructan biosynthesis and freezing tolerance, and induced expression of PpFEH during fructan accumulation could also suggest a role in fructan biosynthesis. However, based on the different PpFEH transcription rates among varieties and similar expression of PpFEH and PpCAP, we suggest that PpFEH is more likely to be involved in mediating freezing tolerance, e.g., by regulating the cell osmotic potential through fructan degradation.

Kit for detection of fungal endophytes of grasses yields inconsistent results

Summary1. The Agrinostics field immunoblot assay is a colour‐imprint assay originally developed for routinely and rapid detection of mycotoxin‐producing fungi Neotyphodium spp./Epichloë spp. from samples of pasture, turf, cereals and seeds of agricultural grasses.2. In addition the Agrinostics immunoblot assay has been used and recommended for exploring the presence and ecological role of Neotyphodium and the closely related Epichloë in several cool season grasses.3. Here we demonstrate that this method is not limited to detection of only these two species, as several other fungal endophyte genera or species also yielded positive results when mycelia were loaded onto cards. Moreover, other closely related endophyte genera or species were found to yield negative result. Thus, the assay is neither specific to isolates of Neotyphodium/Epichloë nor is it universal for fungal endophyte detection.4. Our study underscore the fact that the Agrinostics field immunoblot assay should not be used on its own for field research into the broader ecological significance of Neotyphodium/Epichloë.5. We suggest that the assay may be best suited for use in agricultural fields or in controlled greenhouse experiments for hyphal load estimates, and should always be accompanied by other methods (e.g. microscopic visualization, DNA‐sequencing) to confirm infection frequencies and certify that the endophyte present actually is Neotyphodium/Epichloë.

Limits to recruitment of tall fescue plants in poplar silvopastoral systems of the Pampas, Argentina

Forage production in silvopastoral systems of the Flooding Pampa is based on cool season grasses with a relatively asynchronous phenology regarding their accompanying deciduous trees. However, the productivity of cool season grasses in these systems is usually low. The hypothesis of this work is that the low productivity of cool season grasses is caused by tree litter constraining plant recruitment. Emergence and establishment (reproductive propagation), and tillering (vegetative propagation) patterns of tall fescue, a cool season grass in the region, were studied in two pairs of adjacent non-afforested and afforested poplar stands (tree age 26–28 years, tree density 453–797 plants ha−1). Observational and manipulative (i.e. addition of seeds, leaf litter removal) experiments indicated that the recruitment of tall fescue plants is strongly limited by the fall of poplar leaves over emerged seedlings, during autumn. Results suggest that any management practice capable of removing poplar litter, either through grazing or machinery, could neutralize this limitation enhancing the herbaceous primary production of the system.

Improving emergence and early seedling growth of two cool season grasses affected by seed priming under saline conditions

Soil salinity threatens initial stages of emergence and early seedling growth in cool season grasses, although it may be tolerant in its adult stages. Today, seed priming has been known as an effective technique for improving seed germination, seedling vigor, and emergence rate and seedling establishment under different environmental stresses. A pot experiment was conducted to evaluate osmopriming effects in ameliorating emergence rate (ER) and final emergence percentage (FEP), seedling growth, Na+ and K+ accumulated in shoot at early growth stages of two cool season grasses including tall wheat grass (Agropyron elongatum Host.) and bulbous barley (Hordeum bulbosum L.) when seeds were imbibed with CaCl2, -1.5 MPa, and NaCl, -1 MPa for a duration of 2 and 5 days respectively, in response to seven salinity concentrations of NaCl (0, 50, 100, 150, 200, 250 and 300 mM) under greenhouse conditions. With increasing salinity levels, ER and FEP and seedling growth were significantly decreased in both grasses for primed and non-primed (control) seeds (p 0.05) but for non-primed seeds increasing the accumulation of Na+ in shoot, led to significant decline (r= -0.62, P< 0.01) of shoot dry weight. The results suggest that seed priming could significantly improve the threshold value especially for FEPin both grasses under different levels of salinity. Also, it seems that seed priming could better improve root and shoot growth at early seedling growth stage perhaps by decreasing toxicity of Na+ concentration and adjusting Na+ and K+ ratio under saline conditions. Key words: Early seedling growth, emergence rate, seed priming, salinity stress, cool-season grasses.

Interaction of breed type and endophyte-infected tall fescue on milk production and quality in beef cattle1

Decreased milk production of beef cattle grazing endophyte-infected (EI) tall fescue (TF), an important cool season grass in the southeastern United States, can affect calf growth. The objective was to determine whether a thermal or heat-tolerant Bos taurus breed of cattle, Romosinuano (RO), would tolerate EI TF toxins relative to Angus (AN) cattle. Milk production and quality were examined on AN and RO cows grazing endophyte-free (EF; variety K-31; n = 36) or EI TF (variety K-31; n = 37) along with growth of their Charolais-sired calves in 2007 and 2008 in west central Arkansas. Cows calved between early February and late March (spring). Milk yield and quality, BW, rectal temperature, and serum prolactin were determined at 57.1 +/- 2.6 d postpartum and every 28 d thereafter between April and August. Milk yield was greater in AN compared with RO cows (P < 0.001), but not influenced by forage type (P > 0.88). Percent milk fat was greater in cows grazing EF TF in April, but greater for cows grazing EI TF in July (forage x month, P < 0.001). Percent milk fat was greater for RO than AN cows (P < 0.001). Percent milk protein (P < 0.001) was greater and somatic cell counts (log-transformed; P < 0.001) were less in RO than AN cows. Milk lactose was greater for RO compared with AN cows in June through August (breed x month, P = 0.004). Adjusted weaning BW of calves was similar between EF and EI TF in 2007, but greater for calves from EF than EI TF in 2008 (forage x year, P = 0.03). Rectal temperature was similar between RO cows grazing EF and EI TF, but greater in AN cows grazing EI compared with EF TF in most months (forage x breed x month x year, P < 0.001). Serum prolactin was reduced in both breeds of cows grazing EI TF between April and July of both years and greatest in RO cows grazing EF TF (breed, P < 0.001; forage x month, P < 0.001). These data suggest that RO cows were more thermal-tolerant, but still susceptible to toxins in EI TF as shown by a reduction in serum concentrations of prolactin. However, milk production was not influenced by EI TF as previously observed, but milk fat percent was decreased in early lactation in this group of cows. Milk yield and quality were different between AN and RO cows during the period of lactation observed.

Factors that affect the allergic rhinitis response to ragweed allergen exposure

People with seasonal allergic rhinitis (SAR) respond to allergen exposure differently. To determine the factors that affect the rate and degree of symptom development upon controlled allergen exposure. Study participants underwent skin prick testing (SPT) to selected aeroallergens, completed the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) and the 36-Item Short Form Health Survey, and provided a detailed allergy and exposure history. Nasal eosinophil counts and late-phase responses to SPT were measured. Eligible participants underwent a 3-hour ragweed pollen exposure in the Environmental Exposure Unit, rating rhinoconjunctivitis symptoms every 30 minutes. Data were analyzed using a mixed-effects model for repeated measures. One hundred twenty-three participants completed the study. Skin test reactivity to ragweed was not correlated with the rate of symptom development or with severity. Participants with positive SPT reactions to dust mite, dog, or grass and those with self-reported symptoms to dog or cat exposure tended to develop symptoms earlier and to a greater degree by 90 minutes. Self-report of SAR symptoms during the ragweed or grass season and RQLQ scores were positively associated with the rate and degree of symptom development. No other significant associations were detected. The rate of symptom development upon ragweed exposure was related to concomitant hypersensitivity to perennial allergens and grass pollen as determined by SPT and clinical history. The RQLQ was a powerful predictor of the priming response to ragweed, showing a dose-response-type association. These data suggest that a "prepriming" phenomenon is present in patients with SAR. No correlation was shown between symptomatic responses and degree of SPT reactivity.

Diversity and Functionality of Arbuscular Mycorrhizal Fungi in Three Plant Communities in Semiarid Grasslands National Park, Canada

Septate endophytes proliferating in the roots of grasslands' plants shed doubts on the importance of arbuscular mycorrhizal (AM) symbioses in dry soils. The functionality and diversity of the AM symbioses formed in four replicates of three adjacent plant communities (agricultural, native, and restored) in Grasslands National Park, Canada were assessed in periods of moisture sufficiency and deficiency typical of early and late summer in the region. The community structure of AM fungi, as determined by polymerase chain reaction-denaturing gradient gel electrophoresis, varied with sampling time and plant community. Soil properties other than soil moisture did not change significantly with sampling time. The DNA sequences dominating AM extraradical networks in dry soil apparently belonged to rare taxa unreported in GenBank. DNA sequences of Glomus viscosum, Glomus mosseae, and Glomus hoi were dominant under conditions of moisture sufficiency. In total, nine different AM fungal sequences were found suggesting a role for the AM symbioses in semiarid areas. Significant positive linear relationships between plant P and N concentrations and active extraradical AM fungal biomass, estimated by the abundance of the phospholipid fatty acid marker 16:1 omega 5, existed under conditions of moisture sufficiency, but not under dry conditions. Active extraradical AM fungal biomass had significantly positive linear relationship with the abundance of two early season grasses, Agropyron cristatum (L.) Gaertn. and Koeleria gracilis Pers., but no relationship was found under dry conditions. The AM symbioses formed under conditions of moisture sufficiency typical of early summer at this location appear to be important for the nutrition of grassland plant communities, but no evidence of mutualism was found under the dry conditions of late summer.

Vitamins A, E and fatty acid composition of the eggs of caged hens and pastured hens

AbstractIn the US farmers often market pastured poultry eggs for a premium price, claiming animal and human health benefits. We examined how moving pastured hens to forage legumes or mixed grasses influenced hen (Gallus gallusL.) egg omega-3 fatty acids and concentrations of vitamins A and E. We also compared the eggs of the pastured hens to those of hens fed a commercial diet in cages. We used a cross-over design to compare pasture species: 75 sister hens were assigned to one of three pasture treatment groups: (1) alfalfa (Medicago sativaL.), (2) red and white clover (Trifolium pretenseL. andTrifolium repensL.) or (3) mixed cool season grasses. Groups were rotated to all three pasture treatments, each for 2 weeks and supplemented with 70 g commercial hen mash bird−1day−1. Pasture botanical composition, forage mass, leaf to total ratio and plant fatty acid composition were compared among pasture treatments. Eggs of the pastured hens were compared to eggs of 50 sister hens that were fed only commercial hen mash in cages for the entire 6 weeks. Forage parameters varied somewhat, but did not explain plant linolenic acid variation. Seventeen of the 18 quantified egg fatty acids, and vitamin A concentrations did not (P&lt;0.05) differ among the three pasture treatment groups. Eggs of the hens that foraged grasses had 23% more (P&lt;0.0001) vitamin E than eggs of hens that foraged clover. Compared to eggs of the caged hens, pastured hens' eggs had twice as much vitamin E and long-chain omega-3 fats, 2.5-fold more total omega-3 fatty acids, and less than half the ratio of omega-6:omega-3 fatty acids (P&lt;0.0001). Vitamin A concentration was 38% higher (P&lt;0.05) in the pastured hens' eggs than in the caged hens' eggs, but total vitamin A per egg did not differ. At the end of the experiment, pastured hens weighed 14% less and averaged 15% lower hen-day egg production than caged birds (P&lt;0.0001). Results suggest that grass pastures may enhance vitamin E in eggs of pastured hens more than clover, and pastured hens supplemented with commercial mash will produce eggs with significantly more vitamin E and total omega-3 fatty acids compared to eggs from caged hens fed only commercial hen mash. Pastured hens may have lower body weight and egg production than caged hens, unless they are supplemented adequately to meet their dietary energy and crude protein needs.

Analyses of Louisiana and Mississippi Producers' Samples Reveal Mineral Status of Forages

Feed value analysis results of Louisiana and Mississippi forage samples categorized into cool-season annual grass (CSAG), cool-season legume forage (CSLF), volunteer warm season grass (VWSG), warm-season annual grass (WSAG), and warm-season perennial grass (WSPG) were reviewed focusing on mineral contents, hypomagnesemic tetany potential, and correlation between the organic nutrients and minerals. Except for high K concentrations in all forage types, macro-mineral concentrations of Ca, P, and Mg were marginal in meeting the mineral requirements of actively growing cattle. Percentages of forage with tetany ratio greater than 2.2 were 20.0, 0.0, 10.3, 4.8, and 4.5% in CSAG, CSLF, VWSG, WSAG, and WSPG, respectively. The correlation coefficients between CP and P, Mg, or K were generally positive while those between NDF and the minerals were mostly negative. Results of producers' forage samples revealed deficiencies of most macro and micro-minerals, and significant chances of hypomagnesemic tetany. Producers' long-term sample analysis results did not provide any strong correlation between minerals and energy or protein. Therefore, sample analysis will be necessary to cover micro and macro minerals in addition to energy and protein. Potassium fertilizer management decisions will need to be made carefully based on analysis results of soil and plant tissue.

イネ科花粉症に対するモメタゾンフランカルボン酸エステル水和物点鼻液の治療効果

We studied the clinical effects of mometasone furoate on subjects with seasonal grass pollinosis by comparing nasal and ocular symptom scores, medication scores and symptom-medication scores before and after treatment. Post-treatment scores were significantly lower than pre-treatment, as were vascular endothelial growth factor (VEGF), eosinophilic cationic protein (ECP), and eotaxin concentrations in nasal lavage fluid of treated subjects. Our findings suggest that mometasone furoate is useful in treating seasonal grass pollinosis.

형질전환 톨 페스큐 개발의 최근 동향

Tall fescue is an open-pollinated, perennial, cool season grass species widely used for forage and turf. Tremendous progress has been made in genetic transformation of tall fescue in the past decade. Methods for generating transgenic tall fescue plants have been developed based on biolistic transformation and Agrobacterium-mediated transformation. Potentially useful agronomic genes have been tested to environmental stress tolerance, herbicide tolerance and improve forage quality in tall fescue plants. We review progress in biotechnological improvement of tall fescue and discuss future molecular breeding of this species.