K. H. Asay

Molecular phylogeny of the Pooideae (Poaceae) based on nuclear rDNA (ITS) sequences

Phylogenetic relationships of the Poaceae subfamily, Pooideae, were estimated from the sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The entire ITS region of 25 species belonging to 19 genera representing seven tribes was directly sequenced from polymerase chain reaction (PCR)-amplified DNA fragments. The published sequence of rice, Oryza saliva, was used as the outgroup. Sequences of these taxa were analyzed with maximum parsimony (PAUP) and the neighbor-joining distance method (NJ). Among the tribes, the Stipeae, Meliceae and Brachypodieae, all with small chromosomes and a basic number more than x=7, diverged in succession. The Poeae, Aveneae, Bromeae and Triticeae, with large chromosomes and a basic number of x=7, form a monophyletic clade. The Poeae and Aveneae are the sister group of the Bromeae and Triticeae. On the ITS tree, the Brachypodieae is distantly related to the Triticeae and Bromeae, which differs from the phylogenies based on restriction-site variation of cpDNA and morphological characters. The phylogenetic relationships of the seven pooid tribes inferred from the ITS sequences are highly concordant with the cytogenetic evidence that the reduction in chromosome number and the increase in chromosome size evolved only once in the pooids and pre-dated the divergence of the Poeae, Aveneae, Bromeae and Triticeae.This paper reports factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable

Merits of native and introduced Triticeae grasses on semiarid rangelands

Experiments were conducted on four semiarid range sites to compare stand establishment, productivity, and persistence of several introduced perennial Triticeae grasses with that of their native counterparts. On Intermountain sites with severe water limitations (< 300 mm), native grasses were more difficult to establish, less productive, and less persistent than the introduced grasses. Stands of native grasses declined most rapidly under defoliation. At locations where moisture conditions were more favorable, particularly where more summer precipitation occurred, native Triticeae grasses established and persisted relatively well compared with the introduced entries. Although difficult to establish, stands of the rhizomatous native, western wheatgrass [Pascopyrum smithii (Rydb.) A. Love] in creased during the seasons after establishment. Choice of plant materials to be used in range seeding programs should be based on objective criteria. To do otherwise will perpetuate degradation of soil resources, especia...

Forage nutritional characteristics of orchardgrass and perennial ryegrass at five irrigation levels

the major contributors to NDF (Fisher et al., 1995). Laboratory measures of NDF are correlated with volunAs water resources become limiting, the need to produce stable tary intake (Casler and Vogel, 1999). Fisher et al. (1995) amounts of highly nutritional forage increases. An understanding of how levels of irrigation affect crude protein (CP), digestible neutral reported that energy is closely related to the digestibility detergent fiber (dNDF), in vitro true digestibility (IVTD), and neutral of NDF (dNDF) in forage grasses. Grant (2002) redetergent fiber (NDF) is critical in pasture forage management. Cultiported that NDF digestion can range from 2 to 20% vars of orchardgrass (Dactylis glomerata L.) and perennial ryegrass h 1 in dairy cows (Bos taurus). Oba and Allen (1999) (Lolium perenne L.) were established under a line-source irrigation reported that an increase in forage dNDF resulted in system to evaluate the effect of five water levels (WLs) and three increased dry matter intake and milk yield. They further harvest dates on concentrations of CP, dNDF, IVTD, and NDF. concluded that for every 1% unit increase in dNDF, Perennial ryegrass forage had higher CP, dNDF, and IVTD and lower NDF concentrations than orchardgrass at all harvest dates and within there was a 0.18-kg increase in dry matter intake and a WLs. The most notable trend in nutritional value across WLs was 0.03-kg increase in body weight in dairy cows. Selection the near linear increase in CP ranging from 175 g kg 1 at the wettest for increased CP and in vitro dry matter digestibility WL to 217 g kg 1 at the driest WL. Digestible NDF ranged from 709 in cool-season grasses has resulted in subsequent yield to 757 g kg 1 at corresponding WLs. These trends were particularly reductions in smooth bromegrass (Bromus inermis evident later in the growing season. Orchardgrass maturity (early vs. Leyss.) and reed canarygrass (Phalaris arundinacea L.) late) had little effect on forage nutritional characteristics across WLs. (Casler, 1998; Casler and Vogel, 1999). Combined over WLs, tetraploid perennial ryegrass cultivars averaged higher concentrations of CP, IVTD, and dNDF and lower NDF values Hall (1998) found that maximum forage nutrition was compared with diploid cultivars. In general, as water stress increased, achieved when orchardgrass, smooth bromegrass, and forage nutritional value (i.e., CP and dNDF) increased. reed canarygrass were harvested at 35to 45-d intervals. In another study (Turner et al., 1996), increased CP and lower NDF concentrations were observed under early I in maximizing productivity of irrigated pasand frequent defoliation compared with a hay managetures has escalated with the increased restrictions ment system for festulolium [Xfestulolium braunii (K. on grazing public lands in the western USA. Under Richt) A. Camus], orchardgrass, and prairie grass (Broadequate irrigation, cool-season grass pastures repremus catharticus M. Vahl). Similarly, CP in stockpiled sent some of the most productive grazing lands throughforage of 11 cool-season grasses declined by 55% from out the West (Bateman and Keller, 1956). Increasing June to September (Suleiman et al., 1999). Under the human population and droughty growing conditions same line source, orchardgrass cultivars had higher dry place additional demands on available irrigation water. matter yield and increased water use efficiency than As a result, producers are required to use less water perennial ryegrass cultivars (Jensen et al., 2001, 2002). while trying to maintain stable amounts of highly nutriA line-source irrigation system was developed to evaltious forage. Historically, germplasm improvement in uate plant growth under a gradient of WLs (Hanks et orchardgrass and forage-type perennial ryegrass has foal., 1976). This system has been used to study the recused on forage traits, disease resistance, and agronomic sponses of cool-season grasses to controlled irrigation adaptation to temperate areas (Balasko et al., 1995; levels (Johnson et al., 1982; Asay and Johnson, 1990; Christie and McElroy, 1995; Jung et al., 1996; Casler et Asay et al., 2001; Jensen et al., 2001; Waldron et al., al., 2000). 2002). Literature is limited regarding the effects of irriForage nutrition can be measured by the relative pergation on forage nutritional characteristics under reformance of animals when forage is fed to livestock. peated harvesting. Animal performance is highly influenced by nutrient Objectives of this study were to study the trends in concentration, intake, and digestibility (Buxton et al., CP, dNDF, IVTD, and NDF for nine cultivars of or1996). In the absence of feeding trials, forage nutritive value is often evaluated by measuring such characterischardgrass and seven of perennial ryegrass across an tics as CP, NDF, acid detergent fiber, IVTD, and hemiirrigation gradient. A secondary objective was to evalucellulose (Pavetti et al., 1994). Cell wall constituents are ate the effect of ploidy level in perennial ryegrass and maturity in orchardgrass on any observed differences USDA-ARS, Forage and Range Res. Lab., Utah State Univ., Logan, and trends in forage nutritive value across the irrigaUT 84322-6300. Joint contribution of the USDA-ARS and the Utah tion gradient. Agric. Exp. Stn. Journal Paper no. 7468. Mention of a trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by the USDA or Utah State Univ. Received Abbreviations: CP, crude protein; dNDF, digestible neutral detergent 13 May 2002. *Corresponding author (kevin@cc.usu.edu). fiber; IVTD, in vitro true digestibility; NDF, neutral detergent fiber; NIRS, near infrared reflectance spectroscopy; WL, water level. Published in Agron. J. 95:668–675 (2003).

Breeding Improved Grasses for Semiarid Rangelands

Vast areas of semiarid rangelands in western USA are severely degraded and infested with troublesome weeds such as cheatgrass (Bromus tectorum) and medusahead rye (Taeniatherum asperum). Reseeding with appropriate plant materials that are adapted to the site and competitive enough to replace existing undesirable vegetation is often the most plausible way to reclaim such sites. Unfortunately, many of our native grasses are more difficult to establish and are not as competitive with these exotic weedy grasses as their introduced counterparts, including crested and Siberian wheatgrass (Agropyron cristatum, A. desertorum, and A. fragile). Most native grasses did not evolve under intense management or in association with species as competitive as cheatgrass. Genetically improved germplasms and cultivars of native and introduced (naturalized) grasses have been and are being developed by the Forage and Range Research Laboratory (FRRL) of the United States Department of Agriculture-Agricultural Research Service (USDA-ARS) in cooperation with the Utah Agricultural Experiment Station (UAES) and other agencies. These plant materials have demonstrated the potential for increasing the genetic diversity, protecting watersheds and soil resources, and improving the habitat and grazing potential for livestock and wildlife on semiarid rangelands. Research is also in progress at FRRL to develop germplasm and methodology whereby introduced grasses may be used in combination with natives, and in some instances assist in the establishment of native stands. The proper choice of plant materials must be based on objective criteria if we are to protect our lands and natural resources from further degradation.

Chemometric analyses of Curie-point pyrolysis―mass spectral data for differentiating seeds of Triticeae grass species and hybrids

Abstract Valcarce, R.V., Smith, G.G., Stevenson, D.N. and Asay, K.H., 1990. Chemometric analyses of Curie point pyrolysis—mass spectral data for differentiating seeds of Triticeae grass species and hybrids. Chemometrics and Intelligent Laboratory Systems, 9: 95–105. Hybrid combinations of quackgrass (Elytrigia repens) with bluebunch wheatgrass (Pseudoroegneria spicata) offer substantial economic benefits for western rangelands of the United States if a reliable chemotaxonomic technique can be developed to distinguish hybrid seed from regular quackgrass seed. Curie-point pyrolysis—mass spectrometry (Py-MS) coupled with chemometric analysis is shown to be a potential solution for this problem. Using Py-MS with unsupervised pattern recognition techniques (hierarchical cluster analysis and principal component analysis), the chemical differences that discriminate quackgrass seed from hybrid seed as well as bluebunch wheatgrass seed are clearly elucidated. In addition, discriminant analysis was used to determine the discriminant functions suitable for classifying subsequent unknown grass seed samples.

Russian wildrye nutritive quality as affected by accession and environment

High-quality forage for spring and fall grazing is an important need of ranchers in the Northern Great Plains and Intermountain-West regions of the United States of America and in the prairie provinces of Canada. Russian wildrye [Psathyrostachys juncea (Fischer) Nevski] has been used to meet this grazing need, especially in Canada. However, its use has probably been limited by its reputation for seedling establishment difficulties and scattered reports of grass tetany. The purpose of this research was to characterize the variation in nutritive quality of Russian wildrye accessions used in a multi-location grass tetany project, to access the effect of environment on quality components, and to determine the relationship between forage nutritive quality components and entities associated with grass tetany. Sixty-seven Russian wildrye accessions from the US National Plant Germplasm System were established in spaced-plant nurseries at Logan, UT, Mandan, ND, and Swift Current, SK, Canada. Plants were sampled at...