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On the Ground • Maintaining economic sustainability requires reduced inputs such as mechanically harvested forage. It is estimated that grazing versus feeding cattle during the winter can save 42% to 70% of the yearly input costs in the western United States and Saskatchewan, Canada. • Grass mixtures of intermediate wheatgrass and meadow bromegrass produced 2 and 3 times the stockpiled forage than orchardgrass and native range, respectively. • Economic pay-back period on the initial pasture establishment costs were

Livestock obtain forage by grazing on rangeland. In California annual rangelands, residual dry matter is commonly used to determine proper grazing levels. Rangeland forage biomass and quality can degrade dramatically during the dormant summer period. We examined 25 sites across an annual rainfall gradient (183–492 mm) over 3 contrasting rainfall yr (2015–2017) that varied from 57% to 152% of average annual precipitation. Overall fractional biomass loss was 54.4% (range = 46.5–61.5%) with greater fractional losses occurring in dry years. Biomass losses were related to the amount of peak standing crop and plant composition—both a function of annual precipitation. Fractional seasonal losses from the peak standing biomass in 2015 = 962 kg/ha (61.5% seasonal; 9.7% monthly), 2016 = 1 541 kg/ha (55.0% seasonal; 8.7%monthly) and 2017 = 1 923 kg/ha (46.5% seasonal; 7.3%, monthly). Forage quality metrics were strongly affected by summer weathering processes. Crude protein concentrations decreased by 33.6%, 27.7%, and 21.0% in 2015, 2016, and 2017, respectively. In contrast, relative concentrations of fiber and lignin (acid detergent fiber [ADF] = cellulose + lignin) and in the weathered biomass showed increases for ADF: 44.6% (2015), 32.2% (2016), and 24.1% (2017). Increased lignin varied: 3.4% in 2015, 23.9% in 2016, and 28.0% in 2017. While ADF and lignin concentrations (weathered biomass, kg/ha) increased during the weathering process, the standing stock decreased by 39.3% (ADF) and 46.6% (lignin), compared with overall weathered biomass loss of 54.4% and CP loss of 67.1%. The significant loss of aboveground biomass and forage quality as weathering processes occurred throughout the dry summer period affects livestock grazing strategies. Forage biomass and nutrient losses through the dry season should be considered when determining grazing strategies to achieve proper residual dry matter levels and nutrient supplementation regimes before the onset of the rainy season.

On the Ground • Forage kochia is a perennial semi-shrub that can germinate and establish on a variety of soils and varying climate conditions that range from 127-686 mm of annual precipitation. • ‘Snowstorm’ forage kochia, was released in 2012 as a rehabilitation species to improve forage production for livestock and wildlife. • ‘Snowstorm’ forage kochia is more than 60% taller in stature, produces nearly 70% more forage, and has higher crude protein than ‘Immigrant’ forage kochia. • Overall, land managers believe that ‘Snowstorm’ forage kochia, with all its’ attributes of taller stature, increased forage and crude protein can enhance wildlife habitat.

Resilience is increasingly part of the discussion on climate change, yet there is a lack of breeding for resilience per se. This experiment examined the genetic parameters of a novel, direct measure of resilience to water deficit in tall fescue (Lolium arundinaceum (Schreb.) Darbysh.). Heritability, genetic correlations, and predicted gain from selection were estimated for average productivity, resilience, and stability based on forage mass of a tall fescue half-sib population grown under a line-source irrigation system with five different water levels (WL). Resilience was both measurable and moderately heritable (h2 = 0.43), with gains of 2.7 to 3.1% per cycle of selection predicted. Furthermore, resilience was not correlated with average response over environments and negatively correlated with stability, indicating that it was not a measure of responsiveness to more favorable environments. Genetic correlations among WL ranged from 0.87 to 0.56, however in contrast, resilience was either not or slightly negatively genetically correlated with WL except for moderate correlations with the ‘crisis’ WL. Thus, breeding for improved resilience was predicted to have little effect on forage mass at any given individual water deficit environment. Overall, results indicated that this novel metric could facilitate breeding for improved resilience per se to water deficit environments.

Restoring western US rangelands from a site dominated by invasive annuals, such as cheatgrass and medusahead, to a diverse, healthy, perennial plant−dominated ecosystem can be difficult with native grasses. This study describes the establishment and trends in persistence (plant/m2) of native grass cultivars and germplasm compared with typically used crested and Siberian wheatgrasses at four locations in Idaho (one),Wyoming (one), and Utah (two) that range in mean average annual precipitation (MAP) from 290 to 415 mm. Sites were cultivated and fallowed 1 yr before planting using two glyphosate applications to control weeds. We monitored seedling establishment of 10 perennial cool-season grass species and plant persistence over 5 yr. Precipitation during the seeding year varied with the Utah sites locations reviving below MAP (4% and 14%), while the Wyoming and Idaho sites received above MAP at 8% and 26%, respectively. Across these four sites, native grass seedling establishment of bottlebrush squ...

Species from the crested wheatgrass (Agropyron spp.) complex have been widely used for revegetation and grazing on North American rangelands for over 100 years. Focused crested wheatgrass breeding has been ongoing since the 1920s. These efforts resulted in the development of 18 cultivars adapted to western USA and Canadian growing conditions. These cultivars establish rapidly, persist, and provide soil stabilization and a reliable feed source for domestic livestock and wildlife. To address ecological concerns and increase rangeland agriculture efficiency, crested wheatgrass breeding requires new emphases and techniques. This review covers the history of crested wheatgrass breeding and genetics in North America and discusses emerging methods and practices for improvement in the future.

An analysis of biomass and ground cover data collected from six rangeland sites in the Intermountain and Northern Great Plains areas of the United States from 2000 to 2004 was undertaken to characterize the productivity, stability, and resilience of cool‐season perennial grass species. Among the 13 included species, and the 48 cultivars, intermediate wheatgrass [Thinpyrum intermedium (Host) Barkworth & D.R. Dewey], tall wheatgrass [Thinpyrum elongatum (Host) D.R. Dewey], and to a lesser extent crested wheatgrass [Agropryon cristatum (L.) Gaertn. and A. desertorum (Fisch. ex Link) Schult.] possessed the greatest biomass productivity and ground cover. Basin wildrye [Leymus cinereus (Scribn. & Merr.) Á. Löve], thickspike wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm.) Gould], and bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) Á. Löve] were least productive and stable. There were no differences among species or cultivars for biomass resilience and differences for ground cover resilience were limited. Overall, these three statistics provide an interesting comparison among rangeland species, but more long‐term datasets are necessary for greater inferences and more definitive conclusions.

Histone deacetylases (HDACs) play a significant role in a plant&rsquo, s development and response to various environmental stimuli by regulating the gene transcription. However, HDACs remain unidentified in cotton. In this study, a total of 29 HDACs were identified in allotetraploid Gossypium hirsutum, while 15 and 13 HDACs were identified in Gossypium arboretum and Gossypium raimondii, respectively. Gossypium HDACs were classified into three groups (reduced potassium dependency 3 (RPD3)/HDA1, HD2-like, and Sir2-like (SRT) based on their sequences, and Gossypium HDACs within each subgroup shared a similar gene structure, conserved catalytic domains and motifs. Further analysis revealed that Gossypium HDACs were under a strong purifying selection and were unevenly distributed on their chromosomes. Gene expression data revealed that G. hirsutum HDACs were differentially expressed in various vegetative and reproductive tissues, as well as at different developmental stages of cotton fiber. Furthermore, some G. hirsutum HDACs were co-localized with quantitative trait loci (QTLs) and single-nucleotide polymorphism (SNPs) of fiber-related traits, indicating their function in fiber-related traits. We also showed that G. hirsutum HDACs were differentially regulated in response to plant hormones (abscisic acid (ABA) and auxin), DNA damage agent (methyl methanesulfonate (MMS)), and abiotic stresses (cold, salt, heavy metals and drought), indicating the functional diversity and specification of HDACs in response to developmental and environmental cues. In brief, our results provide fundamental information regarding G. hirsutum HDACs and highlight their potential functions in cotton growth, fiber development and stress adaptations, which will be helpful for devising innovative strategies for the improvement of cotton fiber and stress tolerance.

Selection from novel orchardgrass (Dactylis glomerata L.) germplasm sources resulted in the development of an early maturing orchardgrass population. Fifty-eight families comprise this population and were evaluated under frequent and infrequent harvest intervals at Lewiston and Millville, UT, field locations during 2013 and 2014. The objective of this study was to characterize the performance of the individual families when compared with the check cultivars ‘Icon’, ‘Paiute’, and ‘Potomac’. Across the locations and harvest intervals, individual families produced greater herbage dry mass and nutritive value than the check cultivars. Only for maturity (cv. Paiute) did one of the included commercial checks possess a trait value among the statistically greatest for all families. Twenty-two half-sib families were among the families with the statistically earliest maturity, and between three and eight families were among the families with the statistically greatest trait values for herbage dry mass, crude protein, in vitro true digestibility, neutral detergent fiber, and water soluble carbohydrate concentration. Overall, based on the performance of its component families, this early maturing orchardgrass population exhibited potential for developing improved cultivars for both frequent and infrequent harvest management.

The genome constitution of tetraploid Roegneria alashanica Keng has been in question for a long time. Most scientific studies have suggested that R. alashanica had two versions of the St genome, St1St2, similar to that of Pseudoroegneria elytrigioides (C. Yen & J.L. Yang) B.R. Lu. A study, however, concluded that R. alashanica had the StY genome formula typical for tetraploid species of Roegneria. For the present study, R. alashanica, Elymus longearistatus (Bioss.) Tzvelev (StY genomes), Pseudoroegneria strigosa (M. Bieb.) Á. Löve (St), Pseudoroegneria libanoctica (Hackel) D.R. Dewey (St), and Pseudoroegneria spicata (Pursh) Á. Löve (St) were screened for the Y-genome specific marker B14(F+R)269. All E. longearistatus plants expressed intense bands specific to the Y genome. Only 6 of 10 R. alashanica plants exhibited relatively faint bands for the STS marker. Previously, the genome in species of Pseudoroegneria exhibiting such faint Y-genome specific marker was designated as StY. Based on these results, R. alashanica lacks the Y genome in E. longearistatus but likely possess two remotely related St genomes, St and StY. According to its genome constitution, R. alashanica should be classified in the genus Pseudoroenera and given the new name Pseudoroegneria alashanica (Keng) R.R.-C. Wang and K.B. Jensen.

Evaluation of orchardgrass families at two Utah locations identified significant genetic variation for winter injury but not for flowering or biomass production. Repeatability estimates ranged from 0.06 (biomass production) to 0.65 (winter hardiness). This population has utility for the development of cultivars with increased winter hardiness.

Vegetation on the Channeled Scablands of eastern Washington has been altered to a community dominated by medusahead (Taeniatherum caput-medusae [L.] Nevski). Medusahead is used by livestock but becomes unpalatable as the plant matures and seed heads develop, thus decreasing carrying capacity. The objective of this study was to determine if improved cool-season grasses could establish and persist on medusahead-infested rangelands in the region. A split-plot randomized complete block design consisting of four blocks was established at three different locations. Plots were treated with herbicides to remove all vegetation and seeded in 2010. Seeded species included introduced cool-season grass cultivars: Hycrest II crested wheatgrass (Agropyron cristatum [L.] Gaertn.), Vavilov II Siberian wheatgrass (Agropyron fragile [Roth] P. Candargy), Bozoisky II Russian wildrye (Psathyrostachys juncea [Fisch.] Nevski), and a native cool-season grass mix composed of Sherman big bluegrass (Poa secunda J. Presl), Secar Snake River wheatgrass (Elymus wawawaiensis J. Carlson & Barkworth), Bannock Thickspike wheatgrass (Elymus lanceolatus [Scribn. & J. G. Sm.] Gould), and Recovery Western wheatgrass (Pascopyrum smithii [Rydb.] A Love). Sherman big bluegrass was the only native species that established, and frequency was 65% at the end of the study. Hycrest II frequency was 48% at the end of the study. Vavilov II frequency was 50% at the end of the study. Sherman big bluegrass matured early in the season and had greater biomass production than Hycrest II and Vavilov II in May. The later-maturing Hycrest II and Vavilov II were similar in biomass production to Sherman big bluegrass in July. Bozoisky II had poor stand establishment and did not persist. Hycrest II, Vavilov II, and Sherman big bluegrass are forages that can be used for revegetation on the Channeled Scablands of eastern Washington.

Post-translational modifications are involved in regulating diverse developmental processes. Histone acetyltransferases (HATs) play vital roles in the regulation of chromation structure and activate the gene transcription implicated in various cellular processes. However, HATs in cotton, as well as their regulation in response to developmental and environmental cues, remain unidentified. In this study, 9 HATs were identified from Gossypium raimondi and Gossypium arboretum, while 18 HATs were identified from Gossypium hirsutum. Based on their amino acid sequences, Gossypium HATs were divided into three groups: CPB, GNAT, and TAFII250. Almost all the HATs within each subgroup share similar gene structure and conserved motifs. Gossypium HATs are unevenly distributed on the chromosomes, and duplication analysis suggests that Gossypium HATs are under strong purifying selection. Gene expression analysis showed that Gossypium HATs were differentially expressed in various vegetative tissues and at different stages of fiber development. Furthermore, all the HATs were differentially regulated in response to various stresses (salt, drought, cold, heavy metal and DNA damage) and hormones (abscisic acid (ABA) and auxin (NAA)). Finally, co-localization of HAT genes with reported quantitative trait loci (QTL) of fiber development were reported. Altogether, these results highlight the functional diversification of HATs in cotton growth and fiber development, as well as in response to different environmental cues. This study enhances our understanding of function of histone acetylation in cotton growth, fiber development, and stress adaptation, which will eventually lead to the long-term improvement of stress tolerance and fiber quality in cotton.

Allohexaploid (2n = 6x = 42) intermediate wheatgrass (Thinopyrum intermedium), abbreviated IWG, is an outcrossing perennial grass belonging to the tertiary gene pool of wheat. Perenniality would be valuable option for grain production, but attempts to introgress this complex trait from wheat-Thinopyrum hybrids have not been commercially successful. Efforts to breed IWG itself as a dual-purpose forage and grain crop have demonstrated useful progress and applications, but grain yields are significantly less than wheat. Therefore, genetic and physical maps have been developed to accelerate domestication of IWG. Herein, these maps were used to identify quantitative trait loci (QTLs) and candidate genes associated with IWG grain production traits in a family of 266 full-sib progenies derived from two heterozygous parents, M26 and M35. Transgressive segregation was observed for 17 traits related to seed size, shattering, threshing, inflorescence capacity, fertility, stem size, and flowering time. A total of 111 QTLs were detected in 36 different regions using 3826 genotype-by-sequence markers in 21 linkage groups. The most prominent QTL had a LOD score of 15 with synergistic effects of 29% and 22% over the family means for seed retention and percentage of naked seeds, respectively. Many QTLs aligned with one or more IWG gene models corresponding to 42 possible domestication orthogenes including the wheat Q and RHT genes. A cluster of seed-size and fertility QTLs showed possible alignment to a putative Z self-incompatibility gene, which could have detrimental grain-yield effects when genetic variability is low. These findings elucidate pathways and possible hurdles in the domestication of IWG.

Intermediate wheatgrass [Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] plant introductions (PI) have played a critical role in the development of improved intermediate wheatgrass cultivars. The objective of this study was to characterize a large number of intermediate wheatgrass populations over its native range for dry matter yield (DMY), crude protein (CP), in vitro true digestibility (IVTD), neutral detergent fibre (NDF), and rhizome development and genetic diversity and structure to identify superior populations and possible geographical regions in which to collect. Analysis of molecular variance using 643 AFLP bands partitioned 31% of the total genetic variation among these populations with 69% variance detected within populations. Bayesian cluster analysis identified two large groups designated as Asian and European under K = 2. In general, European accessions had greater DMY than did Asian accessions. Observed trends were towards greater CP values in populations with Asian ancestry. Selection index values above zero were observed in populations with European ancestry, and the exception was the late-maturing (208 days to bloom) populations with Asian ancestry. Plant populations 383 551, 383 561, 401 161, 401 173, 440 021, 578 692 (cv. Tegmar) and 598 740 had rhizome scores greater than 7.0. Despite significant differences detected between populations (ΦST = 0.3136; P

The USDA Agricultural Research Service (ARS) announces the release of Charleston Peak Germplasm slender wheatgrass (Elymus trachycaulus (Link) Gould ex Shinners [Poaceae]) as a selected class, genetically manipulated track pre-variety germplasm selected directly from collection D-3269. This collection is unique in that it exhibits short rhizomes not typically found in standard slender wheatgrass and appears to have the ability to accumulate cadmium (Cd) from the soil in its aboveground tissue. In addition, Charleston Peak is currently the only slender wheatgrass plant material that originates in the Great Basin. Charleston Peak Germplasm was collected near Charleston Peak, Clark County, Nevada, at 2438 m above sea level on 30 July 1983 and designated as D-3269 within the ARS Collection of the Triticeae grasses at Logan, Utah. This germplasm is intended for use on arid and semiarid rangelands for revegetation in the Great Basin and Intermountain Region of the western US.

Successful phytoremediation contaminated mine land soils require the identification of plant species that with wide-spread adaptation to multiple ecological sites that exclude or uptake heavy metals of interest. This study observed metal uptake of arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), magnesium (Mn), lead (Pb) and zinc (Zn) in forage (mg kg-1 DM) of alfalfa and nine other dryland and irrigates grass species when grown on soil from Clarks Fork, Cabbage Gulch, and Keating mine sites in Montana. On the Clarks Fork soil, increased tissue concentrations of As, Cd, Cu, and Zn; were greater than observed in normal plant tissue. However, bio-concentration factors (BCF) were 1 in crested wheatgrass, intermediate wheatgrass, meadow and smooth brome grasses, Russian wildrye, tall wheatgrass, orchardgrass, and tall fescue suggest that these species have the ability to uptake Cd particularly on soils with pH levels of 5.01 and 4.26 found Cabbage Gulch and Keating soils compared to more basic Clarks Fork soil. Observed BCF >1 in Hycrest II crested wheatgrass, AI intermediate wheatgrass, Regar and Cache meadow bromegrass, Manchar smooth bromegrass, NewHy RS-hybrid wheatgrass, Bozoisky II Russian wildrye Alkar tall wheatgrass, Paiute and UTDG-101 orchardgrass, and Fawn tall fescue for Mn accumulation warrants further investigation as another option Mn phytoextraction. Only RS-H RS-hybrid wheatgrass had a Zn BCF >1 and may be a candidate for Zn accumulation.

One of the biggest challenges to successfully phytoremediate contaminated mine land soils is the identification of native plants that possess a broad adaptation to ecological sites and either exclude or uptake heavy metals of interest. This study evaluated forage concentrations of aluminum (Al), arsenic (As), chromium (Cr), cadmium (Cd), copper (Cu), iron (Fe), magnesium (Mn), nickel (Ni), lead (Pb), strontium (Sr), and zinc (Zn) in native wheatgrasses (WG) and wildryes (WR) when grown in soil originating from mine tailings from Clark Fork, Cabbage Gulch, and Keating surface mines in western Montana. Despite having metal concentrations that exceeded the upper limits of normal plant tissue for As, Cd, Sr, and Zn, bioconcentration factors (BCF), an indicator of plants ability to extract metals from the soil, were ≥ 1 only for Cd and Mn and were soil specific. Charleston Peak slender WG appears to have some potential has a Cd accumulator when grown on soils with pH levels of 5.01 and 4.26 compared to a more basic soil found in the Clark Fork (pH = 7.64). Due to BCF values ≥ 1 for Mn uptake, all basin WR cultivars/germplasms studied, First Strike slender and Secar WG could be possible materials for Mn accumulators in a phyto extraction program. However, based on BCF values and soil types used, none of the WG and WR studied could be considered as hyperaccumlulator species for Al, As, Cr, Cd, Cu, Fe, Mn, Ni, Pb, Sr, and Zn.

The USDA Agricultural Research Service announces the cultivar release of ‘Bannock II’ thickspike wheatgrass ( Elymus lanceolatus (Scribn. & J.G. Sm.) Gould [Poaceae]). ‘Bannock II’, a 5-clone synthetic, is the result of hybridization among selected genotypes from thickspike wheatgrass cultivars ‘Bannock’ and ‘Schwendimar’ followed by 2 cycles of recurrent selection. The release of ‘Bannock II’ thickspike wheatgrass expands native germplasm available to enhance the success of conservation and revegetation plantings in the Great Basin, Snake River Plain, and Columbia Plateau regions of the Intermountain US. Genetically distinct from ‘Bannock’ and ‘Schwendimar’, ‘Bannock II’ possesses greater seedling establishment and seed production then ‘Bannock’, ‘Critana’, ‘Elbee’, ‘Schwendimar’, and ‘Sodar’.

Background and aims Native grasses planted or growing on sites contaminated by heavy metals should be safe for livestock and wildlife. Plant breeders seek to identify genes and quantitative trait loci (QTLs) controlling trace element variation among these grasses.

Intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & D.R. Dewey), a segmental autoallohexaploid (2n = 6x = 42), is not only an important forage crop but also a valuable gene reservoir for wheat (Triticum aestivum L.) improvement. Throughout the scientific literature, there continues to be disagreement as to the origin of the different genomes in intermediate wheatgrass. Genotypic data obtained from newly developed EST-SSR primers derived from the putative progenitor diploid species Pseudoroegneria spicata (Pursh) Á. Löve (St genome), Thinopyrum bessarabicum (Savul. & Rayss) Á. Löve (J = Jb= Eb), and Thinopyrum elongatum (Host) D. Dewey (E = Je= Ee) indicate that the V genome of Dasypyrum (Coss. & Durieu) T. Durand is not one of the three genomes in intermediate wheatgrass. Based on all available information in the literature and findings in this study, the genomic designation of intermediate wheatgrass should be changed to JvsJrSt, where Jvsand Jrrepresent ancestral genomes of present-day Jbof Th. bessarabicum and Jeof Th. elongatum, with Jvsbeing more ancient. Furthermore, the information suggests that the St genome in intermediate wheatgrass is most similar to the present-day St found in diploid species of Pseudoroegneria from Eurasia.

Orchardgrass, or cocksfoot, (Dactylis glomerata L.) is one of the most important forage grasses used in temperate agriculture. Yet, genetic gains are slow and complicated owing to the perennial and autotetraploid nature of orchardgrass. The development of orchardgrass population hybrids may be a way to more efficiently make genetic gains through heterosis. In the study reported herein, we describe the results of a 3 year study of the effect of heterosis on the forage quality of orchardgrass population hybrids managed with supplemental irrigation at a Cache County, UT, USA field site. The population hybrids derived from the orchardgrass cultivars Latar, Paiute, and Potomac; and from six additional germplasm sources from Asia, Europe, and North America. Data reflected July and August harvests from 2008 to 2010 and included crude protein (CP), in vitro true digestibility (IVTD), neutral detergent fiber (NDF), and water soluble carbohydrates (WSC). There were differences (P < 0.05) among the population hybrids and the included check cultivars for each of the traits at both harvest points. Mid-parent heterosis was relatively common and there were several instances of high-parent heterosis and reciprocal effects. Additionally, the population hybrids possessed better mean phenotypic values than the cultivars for July CP (2 g kg−1), and August CP (4 g kg−1), IVTD (7 g kg−1), NDF (−9 g kg−1), and WSC (4 g kg−1). Overall, the results suggest that population hybrids may prove a feasible approach for orchardgrass forage quality improvement.

A potential strategy to address the lack of success of North American orchardgrass (Dactylis glomerata L.) breeding programs to increase forage yield and other agronomic traits is the incorporation of novel sources of germplasm. In an attempt to identify novel orchardgrass germplasm sources with agronomic potential, the study described herein characterized 162 half-sib families (HSFs) from six orchardgrass germplasm populations and three orchardgrass cultivars. Study conditions were Millville, UT, and Rexburg, ID, field sites with data collection from 2008 to 2010. The genotype × location interaction variance differed from zero for dry matter yield, crude protein, in vitro true digestibility (IVTD), neutral detergent fiber, and seed weight. Within location broad-sense heritability differed for all traits at both locations (0.36 ±0.10 to 0.77 ±0.03) except IVTD at Rexburg. For each trait there were HSFs that possessed values similar to or better than the included check cultivars (CCs). Additionally, in several instances the mean phenotype of the HSFs from a specific family was better than the phenotype of the corresponding parental population and/or the mean phenotype of the CCs. Overall, for each trait there existed sufficient genetic variation to develop an elite orchardgrass breeding program for irrigated conditions.

Simple sequence repeat technology based on expressed sequence tag (EST-SSR) is a useful genomic tool for genome mapping, characterizing plant species relationships, elucidating genome evolution, and tracing genes on alien chromosome segments. EST-SSR primers developed from three perennial diploid species of Triticeae, Pseudoroegneria spicata (Pursh) Á. Löve (having St genome), Thinopyrum bessarabicum (Savul. & Rayss) Á. Löve (Jb = Eb = J), and Thinopyrum elongatum (Host) D.R. Dewey (Je = Ee = E), were used to produce amplicons in these three species to (i) assess relative transferability, (ii) identify polymorphic species-specific markers, and (iii) determine genome relationships among the three species. Because of the close relationship between Jb and Je genomes, EST-SSR primers derived from Th. bessarabicum and Th. elongatum had greater transferability to each other than those derived from the St-genome P. spicata. A large number of polymorphic species- and genome-specific EST-SSR amplicons were identified that will be used for construction of genetic maps of these diploid species, and tracing economically useful genes in breeding or gene transfer programs in various species of Triticeae.

Orchardgrass (Dactylis glomerata L.) is a high quality forage grass naturalized to temperate climates. Used extensively in hay and grazing agriculture, hundreds of orchardgrass cultivars have been released over the past 50 years. However, progress in yield and other agronomic characteristics in orchardgrass cultivars has occurred slowly and often inconsistently. One cause of the slow progress could be a lack of genetic diversity among orchardgrass cultivars, or an over-abundance of diversity within cultivars. With an emphasis on North American cultivars, this study assessed the genetic diversity within and among 52 orchardgrass cultivars, breeding lines and accessions. Genetic similarity within cultivars ranged from 52 to 71%, similar to values from wild-land, unselected accessions. Populations from Wisconsin and Missouri breeding efforts that resulted from two cycles of genotypic recurrent selection were included as checks. Neither group of selection populations exhibited more within-population similarity compared to the wild-land accessions (ecotypes) and cultivars. Genetic differentiation was detected only for the selection populations and several cultivars and breeding lines that had a tendency to originate from eastern Asian germplasm and have late flowering times. These results indicated an abundance of genetic variation within the orchardgrass cultivars, but a paucity of genetic differentiation among cultivars.

Rhizomes are prostrate subterranean stems that provide primitive mechanisms of vegetative dispersal, survival, and regrowth of perennial grasses and other monocots. The extent of rhizome proliferation varies greatly among grasses, being absent in cereals and other annuals, strictly confined in caespitose perennials, or highly invasive in some perennial weeds. However, genetic studies of rhizome proliferation are limited and genes controlling rhizomatous growth habit have not been elucidated. Quantitative trait loci (QTLs) controlling rhizome spreading were compared in reciprocal backcross populations derived from hybrids of rhizomatous creeping wildrye (Leymus triticoides) and caespitose basin wildrye (L. cinereus), which are perennial relatives of wheat. Two recessive QTLs were unique to the creeping wildrye backcross, one dominant QTL was unique to the basin wildrye backcross, and one additive QTL was detectable in reciprocal backcrosses with high log odds (LOD = 31.6) in the basin wildrye background. The dominant QTL located on linkage group (LG)-2a was aligned to a dominant rhizome orthogene (Rhz3) of perennial rice (Oryza longistamina) and perennial sorghum (Sorghum propinquum). Nonparametric 99 % confidence bounds of the 31.6-LOD QTL were localized to a distal 3.8-centiMorgan region of LG-6a, which corresponds to a 0.7-Mb region of Brachypodium Chromosome 3 containing 106 genes. An Aux/IAA auxin signal factor gene was located at the 31.6-LOD peak, which could explain the gravitropic and aphototropic behavior of rhizomes. Findings elucidate genetic mechanisms controlling rhizome development and architectural growth habit differences among plant species. Results have possible applications to improve perennial forage and turf grasses, extend the vegetative life cycle of annual cereals, such as wheat, or control the invasiveness of highly rhizomatous weeds such as quackgrass (Elymus repens).

In a previous article, Beschta et al. (Environ Manag 51(2):474-491, 2013) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a challenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO₂ and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20-50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing.

It has been hypothesized that the genetic control of forage traits, especially biomass, for grass plants growing as spaced-plants versus swards is different. Likewise, the genetic control of compatibility in grass&ndash, legume polyculture mixtures is assumed to be different than for forage production in a grass monoculture. However, these hypotheses are largely unvalidated, especially at the DNA level. This study used an intermediate wheatgrass mapping population to examine the effect of three competition environments (spaced-plants, polyculture, and monoculture) on classical quantitative genetic parameters and quantitative trait loci (QTL) identification for biomass, morphology, and forage nutritive value. Moderate to high heritable variation was observed for biomass, morphological traits, and nutritive value within all three environments (H ranged from 0.50 to 0.87). Genetic correlations (rG) among environments for morphology and nutritive value were predominantly high, however, were moderately-low (0.30 to 0.48) for biomass. Six biomass QTL were identified, including three on linkage groups (LG) 1, 6, and 15 that were only expressed in the monoculture environment. Moreover, three biomass QTL on LG 10, 14, and 15 exhibited significant QTL by environment interactions. This study verified that the genetic control of grass biomass in a monoculture versus a grass&ndash, legume mixture is only partially the same, with additional genes expressed in monoculture, and that biomass in widely spaced-plants versus swards is predominantly under different genetic control. These results indicate that selection for improved grass biomass will be most successful when conducted within the targeted monoculture or polyculture sward environment per se.

Basin wildrye ( Leymus cinereus (Scribn. & Merr.) A. Love) and creeping wildrye ( Leymus triti- coides (Buckley) pilg.) are outcrossing peren - nial grasses native to western North America. These divergent species are generally adapted to different habitats but can form fertile hybrids. Cultivars of both species are used in agricul - ture and conservation, but little is known about genetic diversity and gene flow among these species. Therefore, multilocus amplified frag - ment length polymorphism (AFLp) genotypes and chloroplast DNA sequences were evaluated from 536 L. cinereus and 43 L. triticoides plants from 224 locations of western United States and Canada. Bayesian-cluster analysis detected three L. cinereus races corresponding to the Columbia, rocky Mountain, and Great Basin regions. possible admixture between species was detected in specific areas, but only 2.2% of the plants showed more than 10% introgres - sion. The Columbia and Great Basin races were predominantly octoploid whereas most of the rocky Mountain accessions were tetraploid. Approximately 36 and 7% of the AFL p variation was apportioned among species and races, respectively, but no discrete marker differences were detected among these groups. Although species can be distinguished using a relatively small set of AFLp markers showing divergent allele frequencies, at least 30 markers were needed to classify plants by race. Approximately 8 and 11% of the chloroplast DNA sequence variation was apportioned among species and races, but these markers were not practically useful for species or race identification.