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One possible approach for improving the nitrogen (N)‐use efficiency of perennial ryegrass (Lolium perenne L.) pastures and reducing environmental N losses is to select cultivars or incorporate alternative pasture species with lower shoot N concentrations. Viability of this strategy depends on herbage production not being unduly compromised. A pot experiment compared the shoot N concentration requirements of a diverse range of perennial ryegrass cultivars to achieve 90% and 99% of the herbage yield maxima achievable within a 20 day regrowth cycle. This research was undertaken to quantify if and what effect Australasian breeding programs have had on the N nutrition of perennial ryegrass. Our experiment found minimal genetic variation in the shoot N concentration requirements for vegetative perennial ryegrass swards to achieve near‐maximum herbage yields of living biomass. Across evaluated cultivars, swards achieving 90% and 99% of herbage yield maxima required minimum shoot N concentrations (on a dry matter basis) of 2.56% and 2.87%, respectively. Our experiment also evaluated the shoot N concentration requirements of modern summer‐active cocksfoot (syn. orchardgrass; Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb.) ecotypes. We found their shoot N concentration requirements to achieve optimal herbage growth to be similar to those of perennial ryegrass. Taken together, our results suggest that within the perennial ryegrass genome, and among similar high yielding temperate perennial grasses, there may be limited scope for selecting plants with lower shoot N concentration requirements. [ABSTRACT FROM AUTHOR]

Perennial grasses have got greater attention in the past decade due to their potential to be productive over several years and their positive impacts on the environment. A great resource in this regard are the native species, which are well adapted to the specific conditions of the environment, but are often underestimated and irrationally used. The objects of study in the present research were 8 grasses (Festuca rubra, Lolium perenne, Dactilis glomerata, Arrhenatherum elatius, Festuca arundinacea, Briza maxima, Trisetum flavescens, Agrostis alba), typical for the Middle Balkan Mountains region, in order to assess their productivity and stability. The two-factor analysis of variance in terms of dry mass yield revealed significant influence of the factors of species, environment, and their interaction. During the 9-year experimental period, the highest yield was demonstrated by F. rubra (5.75 t ha-1), followed by F. arundinacea (5.54 t ha-1) and A. elatius (5.43 t ha-1). The stability parameters, calculated by the methods of regression analysis defined as stable the species of A. elatius and A. alba, and those, calculated by variance and non-parametric analyzes - F. rubra, D. glomerata and F. arundinacea. Differences in the stability assessment of the individual parameters are due to the fact that the different methods are based on different concepts of stability. The GGE biplot analysis, which integratedly assesses the species for their productivity and stability, identified F. arundinacea and A. elatius as the most favorable combining of these indicators. Trisetum flavescens was also characterized by good stability and average productivity. These species are suitable for cultivation in a wide range of environmental conditions. [ABSTRACT FROM AUTHOR]

Aphids are major pests of cereal and pasture grasses throughout the world, vectoring disease and reducing plant production. There are few control options other than insecticides. Epichloë endophytes that produce loline alkaloids in their hosts provide a possible mechanism of control, with both meadow fescue and tall fescue naturally infected with loline-producing endophytes showing a resistance to Rhopalosiphum padi. We screened Elymus spp. naturally infected with endophytes that produced loline alkaloids at concentrations known to affect aphids on fescue but found no effect on these insects infesting Elymus. A synthetic loline-producing endophyte association with rye also had no effect on the aphids. After hypothesizing that the lolines were being translocated in the xylem in Elymus and rye rather than the phloem, we tested the rye and meadow fescue infected with loline-producing endophytes against a xylem feeding spittlebug. The endophyte in rye inhibited the feeding of the insect and reduced its survival, whereas the endophyte-infected meadow fescue had no effect on the spittlebug but reduced the number of aphids. Lolines applied to the potting medium of endophyte-free and endophyte-infected rye, ryegrass, and tall fescue resulted in a decrease in the aphid populations on the endophyte-free pasture grasses relative to the untreated controls but had no effect on aphid numbers on the rye. We tentatively conclude that lolines, produced in both natural and synthetic association with Elymus and rye, are partitioned in the xylem rather than the phloem, where they are inaccessible to aphids. [ABSTRACT FROM AUTHOR]

Grasses have developed a wide range of morphological and physiological mechanisms to resist herbivory. For instance, they accumulate silicon (Si) in tissue, as physical defence, and associate symbiotically with foliar Epichloë‐endophytes that provide chemical defence via antiherbivore alkaloids. Recent evidence showed that some Epichloë‐endophytes increase foliar Si in forage grasses; however, whether this impacts insect herbivores is unknown. Furthermore, while Si is primarily a physical defence, it also affects production of plant defensive secondary metabolites; Si supply might therefore affect Epichloë‐alkaloids, although this remains untested.We grew endophyte‐free (Nil) and Epichloë‐infected tall fescue and perennial ryegrass in a factorial combination with or without Si supplementation, in the absence or presence of Helicoverpa armigera. Epichloë‐endophyte strains were AR584 for tall fescue, and AR37, AR1 or Wild‐type (WT) for perennial ryegrass. We assessed how Si supply and Epichloë‐endophytes in interaction with herbivory affected foliar Si and mutualist‐derived alkaloid concentrations. Subsequently, their effects on H. armigera relative growth rates (RGRs) were evaluated.Endophytes generally increased Si concentrations in Si‐supplied plants. In tall fescue AR584 and perennial ryegrass AR37, endophytes increased constitutive (herbivore‐free) and induced (herbivore‐inoculated) Si concentrations by at least 25%; in contrast, in perennial ryegrass, the AR1 endophyte only increased constitutive levels. Si supply did not affect alkaloids produced by AR584 or AR1/WT endophytes; however, in the presence of herbivory, Si supply decreased the induction of alkaloids produced by AR37 endophytes by 33%. For tall fescue, Si supply reduced H. armigera RGR by at least 76%, regardless of endophytic status, whereas, endophyte‐alkaloids played a secondary role only reducing herbivore growth in the absence of Si supply. Conversely, in perennial ryegrass, both Si and endophyte‐alkaloids (regardless of Si supply) reduced herbivore RGR although not synergised.Novel interactions between constitutive and induced Si‐ and alkaloid‐based antiherbivore defences in grasses were observed. Overall, Si had a greater effect on the folivore than endophytes in both grasses. Endophyte defences contributed more to herbivore resistance in perennial ryegrass than tall fescue. We demonstrate that Si and endophytes were not antagonistic and highlight that the protective nature of their interaction varies with the grass‐endophyte species tested. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

Aims: An Italian ryegrass cultivar (Lolium multiflorum Lam. cv. Bb2067), selected and bred for increased leaf magnesium (Mg) concentration in the 1970s, reduced the incidence of hypomagnesaemia in sheep under experimental grazings. Here, we report evidence from archival experiments showing that cv. Bb2067 had consistently greater Mg concentrations at multiple sites. We also aimed to quantify variation in leaf Mg concentration among modern perennial ryegrass (Lolium perenne L.), hybrid ryegrass (Lolium perenne × multiflorum), and tall fescue (Festuca arundinacea Shreb.) cultivars. Methods: Data are reported from unpublished 1980s field-plot experiments for cv. Bb2067 and contemporaneous reference cultivars, sown at two UK locations in 1983 and 1984, and from 397 cultivars of modern forage grass in 13 UK-based breeding experiments sampled in spring 2013. Results: Across sites, years and cuts, cv. Bb2067 had a consistently greater leaf Mg concentration and lower potassium (K) concentration and forage tetany index (FTI) than reference cultivars in the 1980s experiments. Seasonal variation in leaf Mg and K concentrations and FTI were observed in the 1980s experiments, with K concentrations being generally greatest and Mg concentrations smallest in spring. Among modern forage grasses, there was large variation in leaf Mg concentration (up to 6.3-fold) and FTI (up to 2.1-fold), both within and between species, which varied independently of yield. Among a subset of hybrid ryegrass cultivars, there is evidence that the high Mg trait is already present in some modern breeding lines, albeit previously unreported. Conclusions: The variation in leaf Mg concentration and FTI among old and new cultivars shows there is considerable potential to breed forages with improved mineral quality to improve livestock health, potentially without compromising yield or other nutritional traits. [ABSTRACT FROM AUTHOR]

Field indicators of forage nutritive value could help farmers with rapid management decisions to optimize timing and intensity of grazing and meet objectives regarding animal nutrition. The objective of this research was to evaluate the likely relationships among leaf blade nutritive value, herbage mass and leaf stage of pasture regrowth under different growing seasons and residual sward heights. Experiments were performed on perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca arundinacea Schreb.) pastures during spring and summer of 2016. In both pastures, three residual sward height treatments (3, 6 and 12 cm) were imposed on plots arranged in a split plot design, replicated in three blocks. Sward plots were harvested 5–6 times at intervals spaced 7–10 days apart to measure herbage mass, plant morphology, neutral detergent fibre (NDF), and the 24‐hr in vitro digestibility of NDF (NDFD) and dry matter (DMD) of leaf blades. Pastures showed strong (R2:.62 to.70), but variable, negative relationships between NDFD and herbage mass that varied with the rate at which pasture grew in each season of experimentation. Although there was a consistent NDFD decline as leaf stage of regrowth progressed (R2:.75 to.97), the NDFD also decreased as residual sward height increased, most notably in tall fescue. Additionally, findings indicate that the greater leaf length plasticity of tall fescue compared to residual sward heights may offer opportunities to manage both post‐ and pre‐grazing targets to achieve tall fescue forages with a similar high nutritive value as perennial ryegrass. However, the evaluation of this hypothesis at the farm level and its impacts on animal intake and performance warrants further careful investigations. [ABSTRACT FROM AUTHOR]

Correction to: I Scientific Reports i https://doi.org/10.1038/s41598-022-08309-7, published online 15 March 2022 The original version of this Article contained errors in Table 1, where the "Type" values of the "Forage grass" were incorrect for "AberDart", "AberEcho" and "AberGlyn", "AberNiche", "AberRoot", "Barolex" and "Davinci". [Extracted from the article]

The depth of water extraction is a key trait in grassland species. For comparing individual plant forms in the field, different ecological studies have proven the efficiency of the isotopic signal of water (δ 18O). To date, there has been no assessment of the aforementioned method within closely related grasslands species. For this study, Festuca arundinacea and Lolium multiflorum plants were grown in nutrient solution and the δ 18O of different plant compartments were compared to the δ 18O of the solution under both high and low transpiration conditions. In both species, the basal part of the tillers, excluding the eldest sheath, closely reflected the isotopic water composition of the nutrient solution, whereas other parts of the plant exhibited a significant enrichment in 18O as a consequence of transpiration. In a second experiment, using the genetic variability within plants obtained from crossing F. Arundinacea with Lolium multiflorum, the study explored the variability of the depth of water extraction and δ 18O under conditions of soil water deficit. A plant nursery of hybrids was established in a greenhouse with plants sewn directly in the soil. Ten neutron probe access tubes were placed close to ten individual plants, which were sampled twice at 38 day intervals, following a period of 14 and 52 days of water deprivation. On these same dates, soil samples were extracted down to 1meter in the vicinity of the 10 studied plants. Water was fully extracted from both plant and soil samples and the isotopic composition was measured. The predawn leaf water potential exhibited large variations in water status among the ten plants studied. The measured plant δ 18O were similar to the values computed from estimated soil water extraction profiles (using neutron probe measurements) and soil δ 18O of the soil water profile. On the second date of sampling, the δ 18O and leaf water potentials of three individual plants (L. Multiflorum) were observed throughout the day, revealing a gradual decrease in 18O content as the plant water potential decreased. The role of short term changes in the soil–root hydraulic conductance on depth of water extraction is discussed in this study. [Copyright &y& Elsevier]

Recent changes in soil testing methodology, the important role of P fertilization in early establishment and soil coverage, and new restrictions on P applications to turf suggest a need for soil test calibration research on Kentucky bluegrass (Poa pratensis L.), tall fescue (Festuca arundinacea Schreb), and perennial ryegrass (Lolium perenne L.). Greenhouse and field studies were conducted for 42 days to examine the relationship between soil lest P levels and P needs for rapid grass establishment using 23 NJ soils with a Mehlich-3 extractable P ranging from 6 to 1238 mg⋅kg-1. Soil tests (Mehlich-1 Mehlich-3, and Bray-1) for extractable P were performed by inductively coupled plasma atomic emission spectroscopy (ICP). Mehlich-3 extractable P and AI were measured to evaluate the ratio of P to AI as a predictor of need for P fertilizer. Kentucky bluegrass establishment was more sensitive to low soil P availability than tall rescue nr perennial ryegrass. Soft test extractants Mehlich-1, Bray-1, or Mehlich-3 were each effective predictors of need for P fertilization. The ratio of P to AI (Mehlich-3 P/AI %) was a better predictor of tall fescue and perennial ryegrass establishment response to P fertilization than soil test P alone. The Mehlich-1, Bray-1, and Mehlich-3 soil test P critical levels for clipping yield response were in the range of 170 to 280 mg⋅kg-1, depending on the soil test extractant, for tall fescue and perennial ryegrass. The Mehlich-3 P/AI (%) critical level was 42% for tall fescue and 33% for perennial ryegrass. Soil test critical levels, based on estimates from clipping yield data, could not be determined for Kentucky bluegrass using the soils in this study. Soil testing for P has the potential to aid in protection of water quality by helping to identify sites where P fertilization can accelerate grass establishment and thereby prevent soil erosion, and by identifying sites that do not need P fertilization, thereby preventing further P enrichment of soil and runoff. Because different grass species have varying critical P levels for establishment, both soil test P and the species should be incorporated into the decision-making process regarding P fertilization. [ABSTRACT FROM AUTHOR]

Accumulated temperature may provide an indicator of the phenology of cool-season grass to assist in the timing of management operations but its value is highly dependent on a reliable measure of phyllochron, i.e. time between the elongation of successive leaves. Field and controlled environment studies with Italian ryegrass (IRG, Lolium multiflorum Lam.) and tall fescue (TF, Festuca arundinacea Schreb.) measured leaf-appearance responses to accumulated temperature with varying conditions of exposure to low temperatures, soil moisture content and nitrogen application. In a controlled environment, soil volumetric water contents below 20% (equivalent to moisture potentials greater than −0·1 MPa) or more frequent exposure to below-freezing air temperatures increased the phyllochron values on the main tiller of IRG and TF. There was no evidence of an interaction between soil moisture content and cold exposure on phyllochron values. Nitrogen application resulted in only small reduction in phyllochron values. In field studies over 4 years the phyllochron values in IRG during the months of January to March were 184, 180, 180 and 167 accumulated °C above 0°C leaf−1, more than double the mean value measured in a controlled environment. A greater understanding of the impact of variable low temperatures and of soil moisture potential on the phyllochron is necessary before accumulated temperature can be used to indicate changes in development stages in grasses in different environments. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the reliability of the n-alkane technique for estimating the species composition of Lolium perenne (ryegrass, L) and Festuca arundinacea (tall fescue, F) mixtures. Samples of L and F were collected in May (period 1) and June 2003 (period 2) on mono-specific swards that were maintained at a height of 9 cm. Seven sets of mixtures containing controlled proportions of L and F were then prepared: 1·00:0, 0·80:0·20, 0·60:0·40, 0·50:0·50, 0·40:0·60, 0·20:0·80 and 0:1·00 of L:F, respectively, in the mixture. The proportion of each species in the mixtures was estimated from measured n-alkane concentrations, and then compared with the actual known proportion. Various n-alkane combinations were tested and compared to establish which combination gave the best estimate. Total n-alkane concentrations, and especially C29- and C31-alkane concentrations, were higher in period 1 than in period 2 for both species. The best n-alkane combination varied between periods, as did the effectiveness of C29-alkane in discriminating between L and F. The species composition of the mixtures was satisfactorily estimated for the majority of n-alkane combinations, providing the combination included n-alkanes with contrasting profiles between both species. A systematic overestimation of the proportion of ryegrass was observed for the 0·50:0·50 mixture. [ABSTRACT FROM AUTHOR]

Breeding for high magnesium (Mg) concentrations has been conducted for several forage species. Mgwell, Magnet, and HiMag are the first experimental strains, bred for increased Mg concentrations of orchardgrass, Italian ryegrass, and tall fescue, respectively. This experiment compared the performance and genetic variability of these high-Mg cultivars grown in solution culture with other cultivars in each species. Three mineral absorption experiments were carried out with one month aged seedlings. Seedlings were evaluated for shoot dry weight, uptake and concentration of Mg, calcium (Ca), and potassium (K), and also the density of these minerals in the shoot. The cultivars of different species behaved differently among the experiments even though the over all environmental condition was kept similar. The high-Mg cultivars showed higher Mg uptake per plant, but the differences were not so distinct. However, the trend in Mg concentration among the cultivars of different species was similar, and the difference between high-Mg cultivars and control cultivars was distinct. The Mg density in the shoot of these cultivars was significantly high. Also the high-Mg cultivars showed lower equivalent ratio, K/(Ca + Mg). Genotypic differences in high-Mg cultivars with others could be distinctly explained by differences in Mg concentration and Mg density in the shoot, which coupled with low K/(Ca + Mg) ratio. These common properties of high-Mg cultivars might be considered as a good parameter for screening. [ABSTRACT FROM AUTHOR]

In a back-crossing programme involving Lolium multiflorum (the recurrent parent) and Festuca arundinacea, the diploid L. multiflorum phenotype was rapidly recovered with the inclusion, in some progeny, of a small number of genes from the fescue parent. In field drought trials derivatives of these backcross populations were on average less drought resistant than the L. multiflorum parental populations, but 3 % of individuals were as drought resistant as F. arundinacea. After only one cycle of selection and polycrossing these drought-resistant Lolium-like plants, the mean drought resistance of most progeny lines was significantly improved, in some cases to near that of F. arundinacea. Available evidence strongly indicates that this improved drought resistance was due to the transfer of genetic material from Festuca into Lolium. These populations will contribute to variety improvement and to our understanding of the genetics and physiology of drought resistance. [ABSTRACT FROM AUTHOR]

Development of tall rescue (Festuca arundinacea Schreb., 2n = 6x = 42) x Italian ryegrass (Lolium multiflorum Lam., 2n = 2x = 14) hybrids would enhance efforts to improve the quality of tail fescue. Two 'Kentucky 31' tail rescue χ 'Lemtal' Italian ryegrass hybrids were obtained via embryo rescue on MS media containing casein hydrolysate, ascorbic acid and sucrose. Chromosome pairing at metaphase I had an average of more than 12 bivalents per cell. Since festuca-Lolium pairing can account only for seven of the paired chromosomes. intergenomic as well as interspecific chromosome pairing is indicated. There was no cytoplasmic effect on chromosome pairing. To determine if enzymes could be used as genetic markers for distinguishing hybrids from self-contaminants in crosses, zymograms of PGI, 6-PGD, MDH, GOT and ACPH were obtained from parents and hybrids using starch gel electrophoresis. PGI, 6-PGD and MDH had fewer bands in the diploid ryegrass, as compared with the hexaploid tall rescue and the tetraploid hybrid. [ABSTRACT FROM AUTHOR]

Forage grass production is an important component of profitable dairying along the Pacific Northwest coast. Neutral detergent fiber digestibility (NDFD) is increasingly being used in ration formulation and forage benchmarking. However, data on differences in NDFD between and within cool-season grass species is limited. Therefore, the objective of this study was to determine if NDFD differs between and within species. In experiment 1, 15 cool-season grass varieties were replicated 3 times each in 6 m2 randomized field plots. Included were 5 varieties each of perennial ryegrass (Lolium perenne), orchardgrass (Dactylis glomerata), and tall fescue (Lolium arundinaceum). In experiment 2, three diploid and three tetraploid cool-season ryegrass varieties (Lolium perenne) were replicated 3 times each in 6 m2 randomized field plots. Plots were mechanically harvested six times at approximately 28 d intervals beginning in March. Forty eight-hour in vitro neutral detergent fiber (NDF) digestibility was determined using 0.3 g of sample in F57 bags in a DaisyII Incubator (Ankom Technology, Fairport, NY). In experiment 1, yield (2124±79 kg DM/ha/cutting) was similar across species. Neutral detergent fiber was less for ryegrass compared to orchardgrass (47.1 vs 48.5±0.4%; P < 0.01), but similar to both of these grasses was tall fescue (48.0%). Neutral detergent fiber digestibility was greater for ryegrass compared to orchardgrass and tall fescue (80.4 vs 77.5±0.6% of NDF; P < 0.01). Digestible NDF did not differ and was 37.4±0.3% of DM or 799±32 kg/ha/cutting. Neutral detergent fiber increased (linear; P < 0.01) and NDFD decreased (quadratic, cubic; P < 0.05) as the growing season progressed. In experiment 2, yield (2220±110 kg DM/ha/cutting), NDF (47.2±0.5%), NDFD (80.7±0.5%), and digestible NDF (38±0.4% of DM and 851±47 kg DM/ha/cutting) were similar for diploid and tetraploid ryegrasses. These results indicate species, when managed intensively, has little effect on yield and digestibility. [ABSTRACT FROM AUTHOR]