Search Results (7)

Pathogenesis from soil- and seed-borne fungi can limit the survival and growth of native seeds and seedlings. Fungicides can combat fungal pathogens, but in some studies, fungicide treatments were ineffective at improving seedling emergence over untreated seed. Such studies suggest that low fungal presence due to dry conditions may be the cause of fungicide ineffectiveness in some years and sites. This study tested whether a fungicide treatment’s effectiveness is indeed related to the amount of fungi in the soil. We compared the emergence and biomass produced from Pseudoroegneria spicata seed that was uncoated, coated with no active ingredient, and fungicide-coated, across five soil treatments promoting different levels of fungal biomass. For uncoated seed, both percent emergence and total biomass of seedlings were highest in autoclaved soil and declined when fungi were present, but the level of fungus did not impact emergence or biomass for fungicide-coated seed. When grown in autoclaved, untreated, or low-fungus soils, percent emergence and total biomass from fungicide-coated seeds were not significantly different from uncoated seeds. However, in medium- and high-fungus soils, the percent emergence and total biomass from fungicide-coated seeds were more than two times greater than uncoated seed (p < 0.05). These results indicate that fungicide treatments can be effective at increasing restoration success for P. spicata, but the effectiveness of the fungicide treatment depends on the microbial environment of the planting site. Full article

Dormant forage is generally understood to be low-quality, but how and why it changes over the dormant season have not been well studied. Therefore, this study evaluated the changes in the forage quality of bluebunch wheatgrass (Pseudoroegneria spicata) and Idaho fescue (Festuca idahoensis) over the course of the dormant season and in response to concurrent environmental conditions. We collected forage samples every 14 days for two consecutive winters in southwestern Montana, USA. Samples were analyzed for crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF). A suite of environmental metrics was derived from PRISM weather data. Data were analyzed with a linear mixed model and the STATICO ordination method. Crude protein and ADF varied throughout the winter across both years, with CP ranging from 1.9–4.0% and ADF from 37–42%. The differences between species were more pronounced and more consistent in CP. The differences between years were more pronounced in ADF and NDF. Relative temperature explained the most variation in forage quality. Crude protein is positively correlated with short-term warmer temperatures, whereas NDF is positively correlated with longer-term warmer temperatures. This demonstrates that forage quality can change over the dormant season and is influenced by winter weather events. Full article

Re-establishing native plants while controlling invasive species is a challenge for many dryland restoration efforts globally. Invasive plants often create highly competitive environments so controlling them is necessary for effective establishment of native species. In the sagebrush steppe of the United States, invasive annual grasses are commonly controlled with herbicide treatments. However, the same herbicides that control invasive annual grasses also impact the native species being planted. As such, carbon-based seed technologies to protect native seeds from herbicide applications are being trialed. In addition to controlling invasive species, ensuring good seed-to-soil contact is important for effective establishment of native species. In this grow room study, we explored the impact of different seed ameliorations when no herbicide was applied and when herbicide was applied. We selected two native species that are important to the sagebrush steppe for this study—the sub-shrub Krascheninnikovia lanata and the perennial bunchgrass Pseudoroegneria spicata—and used three different seed ameliorations—seed pelleting with local soil alone, local soil plus activated carbon and activated carbon alone—to ensure both greater seed-to-soil contact and protection against herbicides. Shoot and root biomass data were collected eight weeks after planting. We found that when herbicide was not applied, K. lanata had the strongest response to the soil alone amelioration, while P. spicata had the strongest response to the activated carbon alone amelioration. However, when herbicide was applied, K. lanata performed best with the soil plus activated carbon treatments, with an average 1500% increase in biomass, while P. spicata performed best with the activated carbon alone treatments, with an over 4000% increase in biomass, relative to bare seed. The results from our study indicate that there is a positive effect of local soils and activated carbon as seed ameliorations, and further testing in the field is needed to understand how these ameliorations might perform in actual restoration scenarios. Full article

In the United States, rangelands comprise 30% of the total land cover and serve as a valuable resource for livestock, wildlife, water, and recreation. Rangelands vary in climate and are often subject to disturbances like drought and wildfire. Historic wildfire trends have indicated an increase in wildfire size and frequency, raising societal and ecological concerns about the management of these lands, both pre- and post-wildfire. While there has been investigation into the effects of grazing prior to a wildfire on fire severity and plant mortality, there is limited research related to grazing post-wildfire even though current management paradigms suggest deferring grazing rangeland for two years after a wildfire to avoid additional stress on native plant species. Based on the diversity found across rangeland ecotypes and history with wildfire, the two-year deferment recommendation may need to be reconsidered for some ecosystems. Species found in perennial bunchgrass rangelands like Pseudoroegneria spicata (bluebunch wheatgrass) and Festuca idahoensis (Idaho fescue) may be less susceptible to post-fire grazing than initially thought, necessitating the need for research into different rangeland ecosystems. Full article

Effective native plant materials are critical to restoring the structure and function of extensively modified ecosystems, such as the sagebrush steppe of North America’s Intermountain West. The reestablishment of native bunchgrasses, e.g., bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] À. Löve), is the first step for recovery from invasive species and frequent wildfire and towards greater ecosystem resiliency. Effective native plant material exhibits functional traits that confer ecological fitness, phenotypic plasticity that enables adaptation to the local environment, and genetic variation that facilitates rapid evolution to local conditions, i.e., local adaptation. Here we illustrate a multi-disciplinary approach based on genomic selection to develop plant materials that address environmental issues that constrain local populations in altered ecosystems. Based on DNA sequence, genomic selection allows rapid screening of large numbers of seedlings, even for traits expressed only in more mature plants. Plants are genotyped and phenotyped in a training population to develop a genome model for the desired phenotype. Populations with modified phenotypes can be used to identify plant syndromes and test basic hypotheses regarding relationships of traits to adaptation and to one another. The effectiveness of genomic selection in crop and livestock breeding suggests this approach has tremendous potential for improving restoration outcomes for species such as bluebunch wheatgrass. Full article

To reduce maladaptation in cultivated seed lots, seed transfer zones (STZs) have been developed for grasslands and other habitats using morphological traits and phenological measurements that only capture the first day of events such as flowering and seed ripening. Phenology is closely linked to plant fitness and may affect genetic loss during harvests of seed raised for ecological restoration. Here, we measured the detailed phenologies of 27 populations from six STZs of bluebunch wheatgrass (Pseudoroegneria spicata) (Pursh) Á. Löve (Poaceae) raised in a common garden to test whether existing STZs created using a combination of plant morphology and “first-day” phenological measurements adequately capture population-level variation in season-long, detailed phenologies. We also used detailed phenologies to test whether genetic losses may occur during single-pass harvests of commercial seed. Mixed and random effect models revealed differences in detailed reproductive phenology among populations within two of six STZs. The number of individual plants within an STZ not producing harvestable seed during peak harvest levels indicated that 10–27% of individuals from a seed lot could be excluded from a single-pass harvest. Although our findings generally support current STZ delineations for P. spicata, they point to the possible precautionary importance of sourcing from multiple populations and harvesting with multiple passes when resources permit. Full article

Starch, as the main component of grain in cereals, serves as the major source of calories in staple food and as a raw material for industry. As the technological and digestive properties of starch depend on its content, the management of its components, amylose and amylopectin, is of great importance. The starch properties of wheat grain can be attuned using allelic variations of genes, including granule-bound starch synthase I (GBSS I), or Wx. The tertiary gene pool, including wheatgrass (Thinopyrum) species, provides a wide spectrum of genes-orthologs that can be used to increase the allelic diversity of wheat genes by wide hybridization. Octaploid partial wheat–wheatgrass hybrids (amphidiploids, WWGHs) combine the complete genome of bread wheat (BBAADD), and a mixed genome from the chromosomes of intermediate wheatgrass (Thinopyrum intermedium, genomic composition J^rJ^rJ^vsJ^vsStSt) and tall wheatgrass (Th. ponticum, JJJJJJJ^sJ^sJ^sJ^s). Thus, WWGHs may carry Wx genes not only of wheat (Wx-B1, Wx-A1 and Wx-D1) but also of wheatgrass origin. We aimed to assess the level of amylose in starch and investigate the polymorphism of Wx genes in 12 accessions of WWGHs. Additionally, we characterized orthologous Wx genes in the genomes of wild wheat-related species involved in the development of the studied WWGHs, Th. intermedium and Th. ponticum, as well as in the putative donors of their subgenomes, bessarabian wheatgrass (Th. bessarabicum, J^bJ^b) and bluebunch wheatgrass (Pseudoroegneria stipifolia, St₁St₁St₂St₂). Although no significant differences in amylose content were found between different WWGH accessions, SDS-PAGE demonstrated that at least two WWGHs have an additional band. We sequenced the Wx gene-orthologs in Th. bessarabicum, P. stipifolia, Th. intermedium and Th. ponticum, and developed a WXTH marker that can discriminate the Thinopyrum Wx gene in the wheat background, and localized it to the 7E chromosome in Th. elongatum. Using the WXTH marker we revealed the allelic polymorphism of the Thinopyrum Wx gene in the studied WWGHs. The applicability of Thinopyrum Wx genes in wheat breeding and their effect on starch quality are discussed. Full article