Leymus Angustus Research Articles

Comparative and Phylogenetic Analysis of Complete Chloroplast Genomes in Leymus (Triticodae, Poaceae).

Leymus is a perennial genus that belongs to the tribe Triticeae (Poaceae) which has an adaptive capacity to ecological conditions and strong resistance to cold, drought, and salinity. Most Leymus species are fine herbs that can be used for agriculture, conservation, and landscaping. Due to confusion taxonomy within genera, the complete chloroplast (cp) genome of 13 Leymus species was sequenced, assembled, and compared with those of three other previously published Leymus species (Leymus condensatus, Leymus angustus, and Leymus mollis) to clarify the issue. Overall, the whole cp genome size ranged between 135,057 (L. condensatus) and 136,906 bp (Leymus coreanus) and showed a typical quadripartite structure. All studied species had 129 genes, including 83 protein-coding genes, 38 transfer RNAs, and 8 ribosomal RNAs. In total, 800 tandem repeats and 707 SSR loci were detected, most of which were distributed in the large single-copy region, followed by the inverted repeat (IR) and small single-copy regions. The sequence identity of all sequences was highly similar, especially concerning the protein-coding and IR regions; in particular, the protein-coding regions were significantly similar to those in the IR regions, regardless of small sequence differences in the whole cp genome. Moreover, the coding regions were more conserved than the non-coding regions. Comparisons of the IR boundaries showed that IR contraction and expansion events were reflected in different locations of rpl22, rps19, ndhH, and psbA genes. The close phylogenetic relationship of Leymus and Psathyrostachys indicated that Psathyrostachys possibly is the donor of the Ns genome sequence identified in Leymus. Altogether, the complete cp genome sequence of Leymus will lay a solid foundation for future population genetics and phylogeography studies, as well as for the analysis of the evolution of economically valuable plants.

Priming seeds in aqueous smoke solutions to improve seed germination and biomass production of perennial forage species

Seeds of many forage species have dormancy, delaying germination in the field. Species from semi-arid environments may have adaptation to fire, therefore, the effects of priming seeds of common forage species in aqueous smoke solutions were studied. Seeds of eight grasses and two legumes were primed in serial dilutions of aqueous smoke solutions and then dried before germination tests. Depending on the species and concentrations of solutions, priming seeds acted independently or in interaction with light and (or) temperature to improve germination in Altai wildrye (Leymus angustus), green needlegrass (Nassella viridula), Kura clover (Trifolium ambiguum), needle-and-thread (Hesperostipa comata), northern wheatgrass (Elymus lanceolatus), orchard grass (Dactylis glomerata), plains rough fescue (Festuca hallii), Russian wildrye (Psathyrostachys juncea), and western wheatgrass (Pascopyrum smithii). Priming seeds of cicer milkvetch (Astragalus cicer) in distilled water or aqueous smoke solutions had no effect o...

Improving Cattle Nutrition on the Great Plains with Shrubs and Fecal Seeding of Fourwing Saltbush

Two in vitro trials were conducted for estimates of dietary percentage of fourwing saltbush (Atriplex canescens; FS) or winterfat (Krascheninnikovia lanata; WF) for improved dietary digestibility when cattle graze mature cool-season grass. Three in vitro trials were conducted to estimate percentage of FS and WF seeds that could survive passage through the bovine gastro-intestinal tract (GIT) with potential for fecal seeding. Mixtures of FS and mature smooth bromegrass (Bromus inermis; SB) or WF and SB had greater apparent digestibility than SB alone (P < 0.0001). There were positive linear relationships (r2 ≥ 0.93) between the amount of each shrub in digested mixtures and digestibility. Similar relationships were observed with mixtures of FS and mature Altai wildrye (Leymus angustus). Germination of Dakota FS seeds in the first trial, incubated for 24 or 48 h, was 55% and 47%, respectively, with no difference in germination of seeds for the 24- and 48-h incubations (P = 0.26), but more seeds germinated if incubated versus not (P ≤ 0.002). Germination of Utah FS seeds, which were incubated for 24 or 48 h with high-, medium-, or low-quality forage, averaged 9% and 8%, respectively. Length of incubation, forage quality, and their interaction did not influence germination (P ≥ 0.45). Germination of nonincubated Utah FS seeds was 21% and greater than for incubated seeds (P = 0.004). Average germination of WF seeds was 0.6% and 0.1% for 24- and 48-h incubations, respectively, with incubation length, forage quality, and their interaction not significant (P ≥ 0.31). Nonincubated WF seeds had greater germination (42%) than incubated seeds (P < 0.0001). Results from the third trial were confirmatory for Dakota FS seed. FS and WF can improve diet quality of grazing cattle in late summer through winter, and some FS seeds have potential for fecal seeding.

Stand Establishment and Persistence of Perennial Cool-Season Grasses in the Intermountain West and the Central and Northern Great Plains

The choice of plant materials is an important component of revegetation following disturbance. To determine the utility and effectiveness of various perennial grass species for revegetation on varied landscapes, a meta analysis was used to evaluate the stand establishment and persistence of 18 perennial cool-season grass species in 34 field studies in the Intermountain and Great Plains regions of the United States under monoculture conditions. Combined across the 34 studies, stand establishment values ranged from 79% to 43% and stand persistence values ranged from 70% to 0%. Intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D. R. Dewey), tall wheatgrass (Thinopyrum ponticum [Podp.] Z.-W. Liu & R.-C. Wang), crested wheatgrass (Agropyron spp.), Siberian wheatgrass (Agropyron fragile [Roth] P. Candargy), and meadow brome (Bromus riparius Rehmann) possessed the highest stand establishment (≥ 69%). There were no significant differences among the 12 species with the largest stand persistence values. Basin wildrye (Leymus cinereus (Scribn. & Merr.) Á. Löve), Altai wildrye (Leymus angustus [Trin.] Pilg.), slender wheatgrass (Elymus trachycaulus [Link] Gould ex Shinners), squirreltail (Elymus spp.), and Indian ricegrass (Achnatherum hymenoides [Roem. & Schult.] Barkworth) possessed lower stand persistence (≤ 32%) than the majority of the other species, and Indian ricegrass (0%) possessed the lowest stand persistence of any of the species. Correlations between environmental conditions and stand establishment and persistence showed mean annual study precipitation to have the most consistent, although moderate effect (r = ∼0.40) for establishment and persistence. This relationship was shown by the relatively poor stand establishment and persistence of most species at sites receiving less than 310mm of annual precipitation. These results will be a tool for land managers to make decisions concerning the importance of stand establishment, stand persistence, and annual precipitation for revegetation projects on disturbed sites.

Salinity Tolerance of Foxtail Barley (Hordeum jubatum) and Desirable Pasture Grasses

Greenhouse studies were conducted to determine the relative salinity tolerance of foxtail barley and seven desirable pasture grasses. Grass species were reed canarygrass, timothy, altai wildrye, tall fescue, tall wheatgrass, orchardgrass, creeping meadow foxtail, and foxtail barley. Grasses were exposed to increasing electrical conductivity levels of NaCl and CaCl2 salt solution over time. Grass species were compared using a cumulative value of salt exposure (ECdays), which was calculated to account for the electrical conductivity (EC) and the time a plant was exposed at that level of conductivity. Salinity tolerance varied among grass species. Increasing EC significantly reduced plant biomass of all species. All grass species experienced a 50% biomass reduction (GR50) between 271 and 512 ECdays in 2008 and between 297 and 575 ECdays in 2009. Foxtail barley was among the most salt tolerant (GR50 = 512 and 525 ECdays), requiring the highest salt exposure in 2008 and the second-highest exposure in 2009 to reduce biomass 50%. Grass mortality increased with increasing EC levels. Reed canarygrass and timothy were most susceptible to increasing salinity, with 50% mortality (LD50) of both grass species occurring between 983 and 1,186 ECdays. Moderate salinity tolerance was exhibited by orchardgrass, which required 1,977 and 1,844 ECdays; creeping foxtail, which required 1,998 and 2,431 ECdays; and tall fescue, which required 2,501 and &gt; 2,840 ECdays to LD50 in 2008 and 2009, respectively. Foxtail barley, altai wildrye, and tall wheatgrass were most tolerant of salinity and persisted with little mortality occurring at 3,033 and 2,840 ECdays in 2008 and 2009, respectively. All grass species with higher growth rates than foxtail barley and altai wildrye were more susceptible to salinity, with the exception of tall wheatgrass. Growth rates of foxtail barley and altai wildrye were less than they were for other grasses, suggesting that slower growth rates may aid in salinity tolerance.

Field-scale assessment of weathered hydrocarbon degradation by mixed and single plant treatments

Phytoremediation is gaining recognition as a viable treatment option for hydrocarbon contaminated soil. However, there is a recognized need for field research to corroborate the findings of controlled environment studies, particularly in cold climate regions. In this study, a two-year field trial was conducted at a weathered hydrocarbon flare-pit site in southeastern Saskatchewan, Canada. Three plants commonly used in phytoremediation mixes (tall wheat grass, Altai wild rye (AWR) and alfalfa), a mix of all plants, and non-planted controls were established and sampled regularly over two growing seasons. Total petroleum hydrocarbon (TPH) concentration and microbial parameters, including endophytic and rhizosphere degrader populations, were measured at 6-week intervals during the growing seasons. Significant differences occurred in degradation trends in the first growing season, with AWR promoting greater than 50% TPH degradation while no cumulative degradation occurred in mixed plant or control treatments. Some of the discrepancy in degradation potential was related to microbial population dynamics. Results show that AWR selectively recruits endophytic hexadecane degraders in response to high TPH concentration ( r, 0.795; p < 0.01) and then maintains these communities during times of environmental stress. During local drought, when most plants experienced significant decreases in rhizosphere and endophytic degrader communities, AWR supported up to 100 times more endophytic hexadecane degraders than the other plants. It is probable that the increased degradation seen in AWR treatments is related to its ability to act as a refuge and hence subsequent source for hydrocarbon degrader communities. As both plants and microbial communities mature, these discrepancies in degradation potential are decreased and cumulative TPH degradation increases in all treatments. Although this study shows that the use of mixed plant treatments may initially hinder the achievement of remediation goals, extenuating factors, including the increased desorption of previously unextractable hydrocarbons, may cause an underestimation of the actual amount of degradation occurring in all treatments.

Leaf epicuticular wax and glaucousness in Altai wildrye grass: which trait is most important to water status?

Epicuticular wax (EW) concentration on the outermost layer of the plant cuticle increases in response to drought stress for many xeric plant species. Glaucousness, or the visible (blue) waxiness of leaf surfaces, is associated with greater EW concentration compared with nonglaucous (green) plants of Altai wildrye grass [Elymus angustus (Trin.) Pilger] (AWR). The contributions of EW concentration and glaucousness to drought stress response have been confounded in previous research. The objective of this study was to determine the effects of EW concentration and glaucousness on water relations of AWR. Water loss rate (WLR) of excised leaves was determined for 180 half-sib AWR lines in 1988, 1989 and 1990 at Swift Current, Saskatchewan, Canada. The mean WLR of blue half-sib lines was 36% less than green half-sib lines (P &lt; 0.05). Among blue (n = 60) or among green (n = 60) half-sib lines, however, there was no significant correlation between WLR and EW concentration. Leaf water potential (Ψ) was determined for 10 blue and 10 green half-sib lines in 1988, 1989 and 1990. Predawn leaf Ψ was 18% higher for blue half-sib lines than for green half-sib lines (P &lt; 0.01), but there was no correlation between Ψ and EW concentration within either group of half-sib lines. Four contrasting synthetics were generated by inter-crossing parent plants that had high or low EW production within either phenotype. The EW concentration, forage yield, predawn Ψ, and midday Ψ were determined for these four synthetics for three sampling dates per year from 1996 to 2001. Selection for high and low EW concentration shifted this trait (P &lt; 0.01) by 0.19 g m-2 between glaucous synthetics and by 0.07 g m-2 between nonglaucous synthetics. Glaucous synthetics exhibited improved predawn Ψ by 0.05 MPa and predawn turgor potential (P) by 0.08 MPa (P &lt; 0.05) compared with nonglaucous synthetics. However, selection for high and low EW concentration did not affect predawn Ψ nor predawn P in either glaucous or nonglaucous synthetics. Selection for blue glaucousness in AWR altered water relations, but selection for EW concentration did not. Key words: Forage breeding, range improvement, forage yield, drought stress, water potential, turgor potential, epicuticular wax

Heifer Production on Rangeland and Seeded Forages in the Northern Great Plains

Integrating use of seeded perennial cool-season grass pastures with native rangeland can increase available forage and provide a high plane of nutrition for grazing livestock. Our objective was to compare performance of yearling beef heifers grazing native rangeland with those grazing an integrated system that included seeded forages. Twice-replicated, 3-ha pastures seeded to either ‘Rosana’ western wheatgrass ( Pascopyron smithii [Rydb.] A. Love), ‘Luna’ pubescent wheatgrass ( Elytrigia intermedia [Host] Nevski), or ‘Hycrest’ crested wheatgrass ( Agropyron cristatum [L.] Gaertn. ssp. desertorum [Fisch. ex Link] A. Love) were grazed in spring, whereas twice-replicated, 3.24-ha pastures seeded to either ‘Alkar’ tall wheatgrass ( Thinopyrum ponticum [Podp.] ZW Liu & RC Wang), ‘NewHy’ hybrid wheatgrass ( Elymus hoffmannii KB Jensen & KH Asay), ‘Bozoisky’ Russian wildrye ( Psathyrostachys juncea [Fisch.] Nevski.), or ‘Prairieland’ Altai wildrye ( Leymus angustus [Trin.] Pilger) were grazed in autumn. Native rangeland was grazed during summer in the integrated system and spring, summer, and autumn in the rangeland treatment. Heifers exhibited greater weight gains on seeded pastures than on native rangeland in spring and autumn of most years. In 2 out of 3 years, heifers that grazed native rangeland during spring gained more ( P = 0.012 for gain head −1 and P = 0.021 for gain head −1 day −1 ) while grazing native rangeland during summer than heifers that grazed seeded pastures in spring. Spring + summer gains averaged (mean ± SE) 0.56 ± kg·head −1 ·d −1 and 73.1 ± kg·head −1 . Livestock managers need to consider their livestock marketing and management strategies when using seeded pastures for seasonal grazing. La integración del uso de praderas sembradas de zacates perennes de estación fría con pastizal nativo puede incrementar el forraje disponible y proveer un buen plano nutricional para el ganado en apacentamiento. Nuestro objetivo fue comparar el comportamiento productivo de vaquillas de ganado de carne de año apacentando un pastizal nativo con vaquillas apacentando un sistema integrado que incluía forrajes sembrados. Praderas de 3 ha, repetidas dos veces, sembradas con “Western wheatgrass” ( Pascopyron smithii [Rydb.] A. Love) variedad ‘Rosana’ y “Pubescent wheatgrass” ( Elytrigia intermedia [Host] Nevski) variedad ‘Luna’ o con “Crested wheatgrass” ( Agropyron cristatum [L.] Gaertn. ssp. desertorum [Fisch. ex Link] A. Love) variedad ‘Hycrest’ fueron apacentadas en primavera, mientras que praderas de 3.24 ha, repetidas dos veces, sembradas con “Tall wheatgrass” ( Thinopyrum ponticum [Podp.] ZW Liu & RC Wang) variedad ‘Alkar’, “Hybrid wheatgrass” ( Elymus hoffmannii KB Jensen & KH Asay) variedad ‘NewHy’, “Russian wildrye” ( Psathyrostachys juncea [Fisch.] Nevski.) variedad ‘Bozoisky’ o con “Altai wildrye” ( Leymus angustus [Trin.] Pilger) variedad ‘Prairieland’ fueron apacentadas en otoño; en el sistema integrado, el pastizal nativo fue apacentado en verano y en el tratamiento de solo pastizal se apacentó en primavera, verano y otoño. En la mayoría de los años, las vaquillas mostraron mayores ganancias de peso en las praderas sembradas que los obtenidos en el pastizal nativo en primavera y otoño. En 2 de 3 años, la vaquillas que apacentaron el pastizal nativo durante la primavera, ganaron más peso ( P = 0.012 para ganancia cabeza −1 y P = 0.021 para la ganancia cabeza −1 dia −1 ) cuando apacentaban el pastizal en verano que las vaquillas que apacentaron en primavera las praderas sembradas. Las ganancias de primavera + verano promediaron 0.56 ± kg·cabeza −1 ·d −1 y 73.1 ± kg·cabeza −1 . Cuando utilicen praderas sembradas para el apacentamiento estacional, los manejadores de ganado necesitan considerar su mercadeo del ganado y estrategias de manejo.

Performance of Perennial Cool‐Season Forage Grasses in Diverse Soil Moisture Environments, Southern High Plains, USA

A continuing need exists to evaluate grasses for irrigated pastures in new and marginal environments. Persistence and yield of Altai wildrye, Leymus angustus (Trin.) Pilg.; beardless wildrye, L. triticoides (Buckley) Pilg.; creeping foxtail, Alopecurus arundinaceus Poir.; grazing bromegrass, Bromus stamineus E. Desv.; intermediate‐pubescent wheatgrass, Elytrigia intermedia (Host) Nevski; meadow bromegrass, B. riparius (Rehmann); meadow fescue, Festuca pratensis (Huds.); orchardgrass, Dactylis glomerata (L.); prairie bromegrass, B. willdenowii (Kunth), syn. B catharticus Vahl var. catharticus; reed canarygrass, Phalaris arundinacea L.; RS wheatgrass, E. repens var. repens L. Desv. ex B.D. Jackson × Pseudoroegneria spicata (Pursh) A. Love; Russian wildrye, Psathyrostachys juncea (Fisch.) Nevski; smooth bromegrass, B. inermis Leyss.; tall fescue, F. arundinacea Schreb.; tall wheatgrass, E. elongata (Host) Nevski; and western wheatgrass, Pascopyrum smithii (Rybd.) A. Love, sown in late summer 1997, were measured from 1999 to 2001 at Tucumcari, NM. Soil moisture treatments were (i) furrow irrigated once before each harvest, which is typical management; (ii) typical irrigation plus irrigated monthly during winter; and (iii) poorly drained, saline/sodic soil, irrigated less than once per cutting. Russian wildrye, RS wheatgrass, tall fescue, tall wheatgrass, and western wheatgrass maintained ground cover across soil moisture treatments. Stand development by Altai wildrye and smooth bromegrass was inconsistent across soil moisture treatments, but eventually complete. Beardless wildrye established stands only in poorly drained soil, while intermediate‐pubescent wheatgrass and meadow bromegrass did not establish well in that soil. No other species established or maintained satisfactory stands after 3 yr in any soil moisture treatment. Winter irrigation increased early‐season yield of intermediate‐pubescent wheatgrass, but decreased late‐season yields of several species, especially Altai wildrye. Distribution of tall wheatgrass and Altai wildrye yield appear complementary, and a binary mixture might provide uniform season‐long yields in this region.

Registration of ‘Mustang’ Altai Wildrye

Registration of ‘Mustang’ Altai Wildrye

Heifer Production on Rangeland and Seeded Forages in the Northern Great Plains

Integrating use of seeded perennial cool-season grass pastures with native rangeland can increase available forage and provide a high plane of nutrition for grazing livestock. Our objective was to compare performance of yearling beef heifers grazing native rangeland with those grazing an integrated system that included seeded forages. Twice-replicated, 3-ha pastures seeded to either ‘Rosana’ western wheatgrass (Pascopyron smithii [Rydb.] A. Love), ‘Luna’ pubescent wheatgrass (Elytrigia intermedia [Host] Nevski), or ‘Hycrest’ crested wheatgrass (Agropyron cristatum [L.] Gaertn. ssp. desertorum [Fisch. ex Link] A. Love) were grazed in spring, whereas twice-replicated, 3.24-ha pastures seeded to either ‘Alkar’ tall wheatgrass (Thinopyrum ponticum [Podp.] ZW Liu RC Wang), ‘NewHy’ hybrid wheatgrass (Elymus hoffmannii KB Jensen KH Asay), ‘Bozoisky’ Russian wildrye (Psathyrostachys juncea [Fisch.] Nevski.), or ‘Prairieland’ Altai wildrye (Leymus angustus [Trin.] Pilger) were grazed in autumn. Native rangeland was grazed during summer in the integrated system and spring, summer, and autumn in the rangeland treatment. Heifers exhibited greater weight gains on seeded pastures than on native rangeland in spring and autumn of most years. In 2 out of 3 years, heifers that grazed native rangeland during spring gained more (P = 0.012 for gain head-1 and P = 0.021 for gain head-1 day-1) while grazing native rangeland during summer than heifers that grazed seeded pastures in spring. Spring + summer gains averaged (mean +/- SE) 0.56 +/- 0.01 kg head-1 d-1 and 73.1 +/- 1.6 kg head-1. Livestock managers need to consider their livestock marketing and management strategies when using seeded pastures for seasonal grazing.

Agronomic characteristics and nutritive value of 11 grasses grown with irrigation on a saline soil in southwestern Saskatchewan

Agronomic and nutritive characteristics of 11 grasses were studied at Swift Current, Saskatchewan on a moderately saline irrigated soil: [smooth bromegrass (Bromus inermis Leyss.), meadow bromegrass (Bromus riparius Rehmann), tall wheatgrass (Elytrigia elongata (Host) Nevski), crested wheatgrass (Agropyron desertorum (Fisch. ex Link) Schult.), intermediate wheatgrass (Elytrigia intermedia (Host) Nevski), slender wheatgrass (Elymus trachycaulus (Linke) Gould ex Shinners), Altai wild ryegrass (Leymus angustus (Trin. Pilger), Russian wild ryegrass (Psathyrostachys junceus (Fisch.) Nevski), Dahurian wild ryegrass (Elymus dahuricus Turcz ex Grieseb), reed canarygrass (Phalaris arudinaceae L.) and creeping foxtail (Alopecurus arundinaceus Poir.)]. Grasses were clipped at threeleaf, heading and seed set. Yield, leaf-to-stem ratio (LSR), botanical composition (BC), crude protein (CP), phosphorus, fibre and in vitro dry matter digestibility (IVDMD) were determined. There were differences (P &lt; 0.05) between the grasses in yield at each growth stage with smooth bromegrass and creeping foxtail having high yields and meadow bromegrass low yields at all growth stages. The BC of most target grasses was greater than 60%. Exceptions were Dahurian wild ryegrass, crested wheatgrass, tall wheatgrass and meadow bromegrass. There were few significant differences between the grasses for LSR, except that Russian and Altai wild ryegrasses and meadow bromegrass had higher LSR (P &lt; 0.05) than the other grasses. Differences in CP, P, neutral (NDF) and acid (ADF) detergent fibres were inconsistent and small at each growth stage but CP and P declined (P &lt; 0.05) while NDF and ADF increased (P &lt; 0.05) with plant maturation. There were differences (P &lt; 0.05) between years and cuts for all traits except between years for yield, BC and LSR at seed set (P &gt; 0.05). Dry matter intake (DMI) NDF and in vivo dry matter digestibility (DMD) were determined for hay cut from each plot using sheep. The relationship between forage NDF and DMI: DMI g kg BW-1 d-1 = 86.5 – 0.09 NDF (r2 = 0.87; RSD = 1.16; P &lt; 0.001)]

The influence of harvest management and fertilizer application on seasonal yield, crude protein concentration and N offtake of grasses in northeast Saskatchewan

The goal of pasture management is to match quantity and quality of herbage to the requirement of the grazing animal. The objective of this study was to examine the effects of harvest management and fertilizer application on annual and seasonal production, protein concentration and N-offtake by eight grass species adapted to the central Aspen Parkland. In this 3-yr splitsplit- plot experiment, grasses were either fertilized annually (50 and 13 kg ha-1 of N and P, respectively) or left unfertilized, and cut either twice annually (two-cut) in early July and late September, or three to four times annually (multi-cut), in early June, early July, early August and late September if there was sufficient herbage. The grasses used in this study were Altai wildrye [Leymus angustus (Trin.) Pilger], creeping red fescue (Festuca rubra L. var. rubra), meadow bromegrass [Bromus riparius (Rehmann)], Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], smooth bromegrass (Bromus inermis Leyss.), crested wheatgrass (Agropyron cristatum L. Gaertn.), intermediate wheatgrass [Elytrigia intermedia (Host) Nevski] and green needlegrass [Nassella viridula (Trin.) Barkworth]. Fertilizer increased yield of the two-cut treatment 15% (P &lt; 0.05) more than the multi-cut treatment. On average, the multi-cut treatment had 32% higher protein concentration than the two-cut treatment throughout the season. Fertilizer significantly increased protein concentration only in the first harvest of the multi-cut clipped plots, probably because the application rate was low. Nitrogen offtake of the multi-cut treatment averaged 24% higher than the two-cut treatment, even though the latter yielded more. Meadow bromegrass showed the most uniform seasonal distribution of yield among the high-yielding grasses under all management systems while smooth bromegrass and crested wheatgrass were generally the poorest. Crested wheatgrass had significantly more first cut production than all other grasses. Meadow bromegrass herbage also had the lowest protein concentrations throughout the growing season among the high producing grasses. Since the protein concentrations were generally higher than required by grazing beef cattle, the meadow bromegrass herbage was the most suitable for this class of cattle. Green needlegrass also showed potential for use in pastures. Key words: Pasture, hay, protein yield, Bromus, Elytrigia, Nassella, Agropyron, Festuca, Psathyrostachys, Leymus

Suitability of altai wildrye ( Elymus angustus) and slender wheatgrass ( Agropyron trachycaulum) for initial reclamation of saline composite tailings of oil sands

Altai wildrye and slender wheatgrass have potential for use in reclamation of amended composite tailings of oil sands.

Seasonal-accumulated growth and forage quality of range grasses for fall and winter grazing

The production and subsequent feeding of forage during winter is a major expense for livestock producers. Fourteen perennial range forage grasses including crested wheatgrass (WG) [Agropyron cristatum and A. desertorum] , intermediate WG [Thinopyrum intermedium], tall WG [T. ponticum], quackgrass [Elytrigia repens] × bluebunch WG [Pseudoroegneria spicata] RS hybrids, Altai [Leymus angustus] wildrye (WR), basin [L. cinereus] WR, smooth bromegrass [Bromus inermis], and orchardgrass [Dactylis glomerata] were evaluated from 1992 to 1994 for total dry matter (DM) production (November harvest only), crude protein (CP), neutral (NDF), and acid (ADF) detergent fiber from November through March in northern Utah. Mean species DM production rankings (P &lt; 0.01) combined across years were: RS hybrids &gt; smooth bromegrass &gt; basin WR &gt; Altai WR &gt; intermediate WG &gt; orchardgrass &gt; tall WG &gt; crested WG. Mean species CP rankings (P &lt; 0.01) combined across years and harvests were tall WG &gt; intermediate WG &gt; orchardgrass &gt; RS hybrids &gt; crested WG &gt; Altai WR &gt; basin WR &gt; smooth bromegrass. Levels of CP remained constant from November through March for all species and entries. Trends in NDF and ADF remained constant from November through January, but NDF increased slightly in March. Crude protein of the dormant grasses was below the level necessary to maintain ruminal function so protein supplementation would be necessary. Key words: Range grasses, winter forage quality, yield, extending the grazing season

Short-lived intercrop forages affect long-term yields of alfalfa and wildrye grass mixtures

Widely seeded rows (&gt;60 cm) of perennial grasses have exhibited greater long-term yield stability, but allow weed invasion in the first years after establishment. A 9-yr study was conducted at a semiarid site at Swift Current, Saskatchewan, Canada, to determine the effects of intercropping oats (Avena sativa L.) and slender wheatgrass [Elymus trachycaulus (Link) Gould ex Shinners] between rows of Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], and Altai wildrye [Leymus angustus (Trin) Pilger] seeded in 90-cm spacings either alone or in alternate rows with alfalfa (Medicago sativa L.). Two rows of oats depressed grass forage production in the year following establishment. Slender wheatgrass intercrops reduced grass forage yield and alfalfa forage yield. However, slender wheatgrass contributed to increased total forage yields while it persisted in the mixture. By the fifth year, it had disappeared from the Russian wildrye plots but persisted 2 more years when intercropped with Altai wildrye. Interseeded companion crops, either annual or short-lived perennials, for forage will give short-term yield gains, but long-lived perennial forages may not recover from the competition in the long-term. Key words: Avena sativa, Elymus trachycaulus, Psathyrostachys juncea, Leymus angustus, Medicago sativa, forage yield

Divergent recurrent selection for seedling tiller number in Altai wildrye

Seedling tiller number is a possible selection criterion to improve seedling establishment of Altai wildrye, Leymus angustus (Trin.) Pilger, an important grass for autumn grazing of beef cattle in semiarid environments. Forty‐two half‐sib families selected for high seedling tiller number (HTN) and eighteen half‐sib families selected for low seedling tiller number (LTN) by four cycles of divergent recurrent selection were compared with four controls, Altai wildrye cultivars Prairieland, Eejay and Pearl, and crested wheatgrass (Agropyron desertorum (Fisch. Ex Link) Schultes), cultivar Nordan, on dryland and irrigated sites at Swift Current, Saskatchewan, Canada. Seedling tiller count, seedling height, tiller weight and seedling dry‐matter yield (DMY) were determined on two plants per plot and DMY was determined for each plot for 2 years post‐establishment. HTN half‐sib families had more, lighter and shorter tillers than LTN half‐sib families. There was a negative correlation (r=–0·42, P &lt; 0·01, n=60) between seedling DMY and tiller number. HTN half‐sib families had higher DMY in post‐establishment years at the dryland site only. Seedling tiller number in Altai wildrye may be related to DMY at sites at which resource availability delays seedling establishment, but selection for HTN will not increase seedling DMY owing to concomitant changes in carbon allocation.

Puccinia coronata var. hordei var. nov.: morphology and pathogenicity

A new variety of Puccinia coronata causing a disease on barley and other gramineous species is described. The fungus is different from other reported forms of P. coronata in both morphology and pathogenicity. Its most prominent characters are the elongated teliospore appendages with dichotomous branching and wide pathogenicity on species in the tribe Triticeae, particularly the genus Hordeum. The name of P. coronata var. hordei is proposed for the rust fungus. The common name ‘crown rust of barley’ is proposed for the disease of barley caused by this rust fungus. Results of inoculation indicated that P. coronata var. hordei is pathogenic on species of Aegilops, Agropyron, Elymus, Elytrigia, Leymus, Pascopyrum, Psathyrostachys, Secale, and Triticum in the tribe Triticeae, and some species of Brachypodium, Bromus, Festuca, and Lolium in the tribe Poeae, and Phalaris in the tribe Aveneae. In the northern Great Plains of the USA, the following native and introduced gramineous species were found naturally infected by P. coronata var. hordei: Bromus tectorum, Elymus canadensis, E. trachycaulus, E. virginicus, Elytrigia intermedia, E. repens, Hordeum jubatum, H. vulgare, Leymus angustus, L. cinerius, L. dahuricus, L. racemosus, Pascopyrum smithii, Psathyrostachys juncea, and Secale cereale.

Productivity and sustainability of four grazed grass – alfalfa mixtures

Forage grasses need to be evaluated in pasture trials in the Great Plains region of North America. The objective of this study was to compare four grass–alfalfa (Medicago sativa L.) mixtures for productivity and persistence when grazed during spring and summer. The grasses were Altai wildrye (Leymus angustus [Trin.] Pilger), intermediate wheatgrass (Elytrigia intermedia [Host] Nevski), meadow bromegrass (Bromus riparius Rehm. syn. B. biebersteinii Roem. &amp; Schult.) and Russian wildrye (Psathyrostachys junceus [Fisch.] Nevski), with grass rows seeded perpendicular to the alfalfa rows. Two sites, 4 km apart, were grazed with yearling beef cattle from 1987 to 1993. Forage yield differed among grass treatments in 4 of 5 years, but differences were inconsistent over time. Five-year mean forage yields and total livestock production were not significantly different among the four grasses. Mean annual forage yields ranged from 800 to 8170 kg ha−1 and were related to the amount of growing season (April–August) precipitation. Carrying capacity ranged from 35 steer grazing days per hectare in 1992 to 176 in 1991. Grasses in the mixtures did have a significant effect on the grass–alfalfa ratio and on ground cover. Alfalfa content was highest when grown with Altai wildrye and lowest when grown with Russian wildrye. Percentage of ground cover by the grass plus alfalfa increased from an average of 3.8% in 1987 to 16.1% at one site and 31.9% at the second site by 1993. Russian wildrye contained the least alfalfa and weeds after 7 yr. Intermediate wheatgrass and Altai wildrye did not compete with invading weeds at one site, or with alfalfa at the other, and should not be recommended for spring–summer pastures in semiarid regions. Meadow bromegrass maintained a balance of grass and alfalfa and further research should confirm its persistence in semiarid climates. Key words: Leymus angustus, Elytrigia intermedia, Bromus riparius, Psathyrostachys junceus, Medicago sativa, grazing with cattle

Degradation of chlorinated benzoic acid mixtures by plant–bacteria associations

AbstractPhytoremediation technologies must tolerate and degrade mixtures of contaminants, as most contaminated sites contain mixtures of compounds. This study assessed the ability of plant–bacteria associations to degrade mixtures of mono‐ and dichlorinated benzoic acids. Sixteen forage grasses and combinations of these grasses with several bacterial inoculants were screened for growth in soil contaminated with various concentrations of mono‐ or dichlorinated benzoic acids. Dahurian wild rye (Elymus dauricus) inoculated with a combination of Pseudomonas aeruginosa strain R75 and Pseudomonas savastanoi strain CB35 reduced 3‐chlorobenzoic acid (3CBA) levels in soil by 74% (i.e., 583 to 149 mg/kg). Meadow brome (Bromus biebersteinii) inoculated with Alcaligenes sp. strain BR60 reduced 2,3‐dichlorobenzoic acid (23diCBA) levels in soil by 56% (i.e., 125 to 55 mg/kg). Altai wild rye (Elymus angitus) inoculated with strains R75 and CB35 reduced 2,5‐dichlorobenzoic acid (25diCBA) levels in soil by 46% (i.e., 211 to 113 mg/kg). Two plant–bacteria associations and uninoculated Dahurian wild rye also degraded mixtures of 3CBA, 23diCBA, or 25diCBA. When 25diCBA was mixed with 23diCBA, uninoculated Dahurian wild rye reduced levels of 25diCBA in soil by 31% and reduced the levels of both 25diCBA and 3CBA by up to 64% when these two contaminants were present in a mixture. Similarly, meadow brome inoculated with BR60 reduced 23diCBA and 3CBA levels by up to 50%. Levels of all three chlorinated benzoic acids were reduced by 53 to 63% by Altai wild rye inoculated with strains R75 and CB35. Our results indicate that plant–bacteria associations can tolerate and degrade mixtures of contaminants in soil but that predictions about phytoremediation of mixed contaminants may not be straightforward.