Thesis (M.S.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

In the southeastern United States, there is a need for a native, cool-season grass component for restoring and reclaiming grasslands and providing quality forage for livestock. Experiments were conducted on southeastern wildrye [Elymus glabriflorus (Vasey) Scribn. & C.R. Ball] to assess agronomic parameters, and establish a base of information for use in future research and breeding programs. Optimal germination requirements (temperature, light, pH, and physical dormancy) were evaluated. Our data suggests that for southeastern wildrye, the optimal temperature required for germination is between 15 and 20oC. Light treatments (constant dark, constant light, short day, and long day) did not influence germination as much as temperature, but can be a limiting factor to stand establishment. Acid source and pH treatments (HCl, H2SO4, and H3PO4 at four pHs 3, 4, 5, and 7) revealed that southeastern wildrye tends to germinate the greatest in soils with a pH greater than 5.0 (HCl at 66.7%), even though germination was observed in lower pHs. Physical dormancy treatments [bearded/glume intact (control), bearded/glumeless, debearded/glume intact, and bearded/glumeless removed] revealed the debearded/glume intact treatment had significantly less mean percentage germination (43.3%) than all other treatments. Planting depth was evaluated under five treatments ranging from surface planting to a depth of 2.54 cm. For the two years this study was conducted, the 0.64 cm treatment had greater percentage of seedlings to emerge than most other treatments. Forage quantity and quality were measured in three experiments. Orchardgrasses and tall fescue entries outperformed native entries in height, yield, and ground cover ratings. Forage quality analysis revealed statistical similarities between southeastern wildrye and improved, non-native cultivars. Harvest management evaluating cutting intervals (20, 30, 40, 60, and 80-d) and subsequent regrowth for two years was conducted. Quantity and quality analysis indicated that harvests should be conducted every 20 to 30-d in order to maintain nutritional requirements for livestock consumption. Future research should include: identification, selection, and development of southeastern wildrye plants with enhanced forage traits (persistence, palatability, lodging resistance) and establishment characteristics (higher germination, awnless), grazing trials, and fertility response trials.

Russian wildrye (Psathyrostachys juncea Fisch. 2n=2x=14, NsNs) is an important forage grass and a potentially useful germplasm in wheat improvement. A standard C-banding karyotype of Ps. juncea has been developed based on the C-bands of chromosomes in geographically diverse materials. Although there are C-banding polymorph isms, the seven pairs of chromosomes can be distinguished from each other according to their basic banding patterns. Based on C-banded karyotype, one deletion-t ranslocation heterozygote, four primary trisomies, one double-deletion trisomic, and two tertiary trisomies were identified. These cytogenetic stocks will be useful in genetic studies of Russian wildrye. Genetic variations in Russian wildrye were analyzed at chromosomal, protein and DNA levels using C-banding, isozymes, and randomly amplified polymorphic DNA (RAPD) techniques, respectively. Due to the self-incompatibility in Russia wild rye, a high level of genetic diversity existed both within and among accessions. In general, accessions originated from the same or neighboring geographical areas showed closer genetic relationships. The results of various approaches for genetic variation analysis suggest that there are tremendous genetic variations in the Russian wild rye germplasm for the effective improvement of this forage grass. Some molecular markers were isolated and characterized in Russian wildrye using RAPD and cloning techniques. These markers may be useful in gene mapping, species identification, studies of evolutionary relationships, and transferring useful genes into cereal crops.

Graduation date: 1996

Thesis (M.S.)--Oregon State University, 2008-01-15. / Printout. Includes bibliographical references (leaves 31-36). Also available on the World Wide Web.

Ecological sites and state-transition models (STMs) have become the preferred means of summarizing plant community dynamics on distinctive types of rangeland. Ecological sites classify rangeland types based on soil-geomorphic and climatic conditions capable of producing a known plant community, while a STM depicts the vegetation dynamics of an ecological site. STMs are usually based on expert opinion rather than site-specific data; however, if they are to gain credibility, STMs must accurately describe the processes that drive plant community dynamics. This study examined three ways of developing process-based STMs using three levels of commonly collected field data. We began by taking field inventories of three ecological sites already mapped in northwestern Utah: Loamy Bottom, Mountain Gravelly Loam, and Upland Loam. The Loamy Bottom site was ideal for developing a data-rich, process-based STM because 1) the site concepts were well-defined, 2) the site was easy to recognize, 3) potential states and transitions had already been hypothesized, and 4) the site was easily accessible. The Loamy Bottom study was designed to link plant community structural indicators to measurable indicators of ecological process. Principal components analysis and cluster analysis were used to classify 14 study plots into four distinct states. Simple linear regression showed relationships between perennial grass cover, perennial canopy gaps, and soil organic carbon. Analysis of variance (ANOVA) linked four general vegetation classes to soil stability measurements. The resulting STM describes the structure and function of four alternative states. The other two STMs, developed for the Mountain Gravelly Loam and Upland Loam ecological sites, used less-intensive data collection methods. Rangeland health assessments, used for the Upland Loam STM, are useful for refining initial ecological site and STM concepts, documenting states, hypothesizing transitions, and locating study locations for future research. Quantitative production and cover estimates, used for the Mountain Gravelly Loam STM, are useful for describing the structure of states, but structural indicators must be coupled with process measurements, as with the Loamy Bottom STM to understand the drivers of state change. A coordinated data collection effort is needed to produce STMs that accurately depict the plant community dynamics of ecological sites.

Southeastern wildrye (Elymus glabriflorus (Vasey ex L.H. Dewey) Scrib & C.R. Ball) is a relatively new perennial cool-season grass that has shown potential as a forage crop in the Southeastern United States. However, there is a lack of research on this species assessing its agronomic performance. To assess the agronomic performance and it’s tolerance to imazapic field trials were established in Newton and Starkville, MS. A forage production trial included five nitrogen (N) 0, 56, 112, 168, and 224 kg N ha -1 (high input) and five annual clover (low input) treatments. Tolerance to imazapic was assessed with applications of four pre- and early post-emergent applications applied at 0.0, 0.35, 0.7, 0.105, and 0.14 kg ai ha -1. Results from both field trials combine to validate southeastern wildrye as a potential forage crop and continued research and development of agronomic traits in this species.

Mutualistic relationships between endophytic fungi and grasses have shown to improve the hardiness of the host. This relationship is common in grasses, including North American native grasses that are important in both forage and grassland ecosystems. Elymus species, such as Canada wildrye (CWR), commonly host the endophytic fungi, Epichloё, while southeastern wildrye (SEWR) may not. In this study, seed of CWR and seed and leaves from local SEWR were assessed for endophyte infection. Infection status was confirmed via histological analysis of seed squashes and leaf peels. Presence/absence of endophyte was determined by scanning for mycelia within seed and between leaf epidermal cells. Following assessment, all SEWR germplasm were endophyte-free (E-), while CWR was endophyte-infected (E+). Endophyte- infected CWR seed were used to isolate and culture the symbiotic endophyte. Isolated endophyte was used to infect E- SEWR. Infection status of SEWR was determined using leaf peels and PCR. This research will help determine if artificial endophyte infection can be performed in SEWR.

A comparative index to digestible nutrients was established for Russian wildrye, crested wheatgrass, and intermediate wheatgrass seeded on foothill areas of Utah. The nutritive values of these grasses were compared by the lignin ratio method, the chlorophyllan ratio method, and the in vivo rumen bag process. Average digestion coefficients computed by the lignin ratio method for dry matter, ether extract, cellulose, and gross energy were highest for intermediate wheatgrass. Protein was more digestible for Russian wildrye. Digestible energy was adequate in all species to meet requirements for late lactation. Results from the chlorophyllan ratio method were excessively high and were not considered valid. Dry matter loss of Russian Wildrye was greater than losses from either of the wheatgrasses. Losses of dry matter due to 24-hour in vivo rumen fermentation and rinsing only of nylon bags were closely correlated.

Medusahead (Taeniatherum caput-medusae ssp. asperum (Simk.) Melderis) is a Eurasian annual grass that infests large areas of U.S. rangelands, dominating former bunchgrass/shrub sites. Squirreltail (Elymus elymoides (Raf.) Swezey) is a native perennial grass that has demonstrated the ability to establish in stands of medusahead. A study conducted on two sites near Burns, OR had the objectives of quantifying competition between medusahead and squirreltail, and determining the effect of moisture availability on competition. Two hundred plots were arranged in a factorial design. Measurements were taken of plant growth, seed production, soil moisture, and climate. Results for the two years are contrasting. The first year was very dry. Medusahead grew and reproduced well, producing a seed crop up to 10 times the amount planted; squirreltail grew poorly and did not reproduce. Samples of squirreltail seed retrieved from the plots in late summer were found to have remained dormant since seeding. The second year had above-average precipitation. Medusahead grew and reproduced well again. Squirreltail grew and reproduced abundantly on one of the sites, both on freshly-seeded plots and on plots containing dormant seeds and surviving plants from the previous year. In all cases, medusahead exhibited stronger interspecific and intraspecific competitive effects than did squirreltail seedlings. With adequate soil moisture, squirreltail reduced average weight and median seed production of individual medusahead plants, but did not reduce medusahead seed production per square meter. Medusahead succeeded in a drought year by utilizing deep soil moisture, and utilized shallower moisture in a wet year. During a wet year in plots containing mature squirreltail, medusahead utilized shallower moisture, while squirreltail strongly utilized much deeper moisture. Interspecific competitive interference by medusahead on squirreltail seedlings suggests the potential benefits of suppressing medusahead during the seeding year for squirreltail in a rehabilitation effort, especially if climatic conditions are conducive to squirreltail germination and establishment. / Graduation date: 1997