Variation in agronomic and morphological traits among Russian Wildrye accessions

Russian wildrye [Psathyrostachys juncea (Fischer) Nevski] accessions in the U.S. National Plant Germplasm System have not been adequately characterized for agronomic and morphological traits. Such characterization would be helpful in development of improved cultivars. Objectives of this study were to (i) measure consistency of dry-matter and seed yields as well as plant height and vigor of 65 Russian wildrye accessions and four cultivars at three diverse test sites, (ii) characterize phenotypic diversity among these accessions using duster analysis, and (iii) define needs for future evaluation and collection of Russian wildrye germplasm. Field tests were conducted at Logan, UT; Mandan, ND; and Swift Current, Saskatchewan, Canada. Dry-matter and seed yields were not consistent among accessions and cultivars at the three locations, and testing at each location was necessary to identify accessions that were best suited to a specific location. Variance component estimates were small and of little consequence for accession x year interaction effects. The 69 entries were grouped into 10 clusters based on multivariate analysis of 17 classification variables. Accessions in Cluster 3 averaged well above the overall test mean for dry-matter yield, seed yield, and plant vigor and have high utility in plant breeding programs in North America. Only four accessions had high levels of resistance to Septoria spraguei Uecker & J.M. Krupinsky, an important foliar disease. Accessions from a defined geographic area tended to cluster, but some accessions from a particular area were spread among several clusters. This emphasizes the value of sampling diverse collection sites within a defined geographic area

Variation in mineral concentration and grass tetany potential among Russian Wildrye accessions

Grass tetany or hypomagnesemic tetany in cattle (Bos taurus) is caused by an imbalance of K, Ca, and Mg in the diet. Indications of grass tetany range from reduced milk yield or weight gain to severe convulsions and death. The risk of grass tetany dramatically increases when the K/(Mg + Ca) ratio of forage exceeds 2.2, especially for dams during early lactation. Russian wildrye [Psathyrostachys juncea (Fisch.) Nevski], a valuable forage species, has ratios well above this level. Our objectives were to determine the mineral concentration and ratio values for 65 accessions of Russian wildrye to select germplasm sources with low tetany ratio and to determine the effects of year, location, and their interactions with accessions. Seedlings of each accession and two checks, Syn A and Mankota, were established in replicated space-plant nurseries at Logan, UT, Mandan, ND, and Swift Current, Saskatchewan, Canada. Years-within-location effects generally produced the largest variance component, while the accession variance was larger than location x accession and location X accession x year interaction variances for K, Ca, Mg, KJ(Mg + Ca) ratio, and Reduced Tetany Potential (RTP) index. Selection for these traits in Russian wildrye germplasm will require multiple years to characterize adequately accessions, breeding lines, or synthetics. The K/(Ca + Mg) ratio of the accessions tested ranged from 2.2 to 3.0 when averaged across sites and years for V4 growth stage. A similar range of ratio values and ranking of the accessions was observed at the E2 growth stage. The three tetraploid accessions evaluated were among the five accessions with the highest tetany ratios. Previously reported forage yield and seed yield means were significantly correlated with K, Mg, and N concentrations and K/(Ca + Mg) ratio. The RTP index was not correlated with forage yield, seed yield, or N concentration. Therefore, selection in Russian wildrye should be based on increased RTP index rather than K concentration or K/(Ca + Mg) ratio to avoid concomitant unintentional selection of reduced forage yield and seed yiel

Soil Quality and Region Influence Performance and Ranking of Switchgrass Genotypes

Development of switchgrass (Panicum virgatum L.) as a dedicated bioenergy feedstock requires intensive and extensive breeding programs that include careful and thoughtful consideration of appropriate target populations of environments (TPEs). The purpose of this study was to evaluate region (climate), soil quality, and N fertilization level as potential factors influencing the choice of TPE. A total of 45 switchgrass genotypes were evaluated in uniform field studies at six field sites defined as prime or marginal soils in New Jersey, South Dakota, and Wisconsin. Region and soil quality had strong interactions with genotype, but N fertilization had little impact on genetic variation or ranking of genotypes. Lowland genotypes were considerably more sensitive than upland genotypes to interactions with environmental factors, probably due to these field sites being outside of the traditional lowland adaptation zones. Genotype rankings were highly inconsistent across regions and soil types, indicating that breeding programs that target marginal soils should be located on soils that represent the appropriate TPE. Furthermore, interactions across the three regions suggest that breeding programs for the lowland ecotype should be subdivided into different sets of TPEs, which are largely a function of hardiness zone and annual precipitation. Lastly, even with negligible interactions involving N fertilization level, future definitions of TPEs should be based on minimal or no N fertilizer applications to allow breeders to select plants with greater N-use efficiency, N-scavenging ability, and N-recycling efficiency

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, SI(, Canada. Plants were sampled at two stages of development over 2 yr. Location, year, and stage of development effects were significant (P < 0.01) for in vitro true dry matter digestibility (IVDMD), crude protein (CP), and neutral detergent fiber (NDF). At the early stages of development used in this study the range in nutritive quality traits among entries was rather narrow. Relatively high positive correlation coefficients between K and IVDMD, and K and CP suggest that breeding for higher nutritive quality may also produce a more tetany-prone forage, because high K concentration is usually associated with grass tetany. On the other hand, Mg concentrations were also highly correlated with IVDMD and CP, and higher Mg concentrations would be beneficial in preventing grass tetany. The K/(Mg + Ca) ratio, which has been suggested as an indicator of grass tetany, was only moderately related to IVDMD, CP, and NDF

Institutional adaptation: Demands for management reform and university administration

Higher education organizations around the world have always faced environmental changes. However, in the past decade altered societal expectations, new public policies, and technological innovations have created an unprecedented set of challenges for universities. Although the borders of universities have opened in new ways for thei