Cultivation legacies in soils after rehabilitation seeding in the Great Basin,USA

Integration of knowledge regarding impacts of historical cultivation on soils for restoration planning is limited even though these legacies can affect land productivity and future land uses for decades. Old fields are often actively transformed through restoration, afforestation, or rehabilitation seeding. Rehabilitation seeding with the introduced perennial grass crested wheatgrass (Agropyron cristatum) was employed on approximately 2 million hectares in the western United States, including old fields in the Great Basin desert region. Seeding continues to be the primary treatment in restoration today, yet a minimal amount is known regarding how the underlying cultivation legacies affect these soils over the long term. We studied sites where rehabilitation seedings overlapped old fields and adjacent noncultivated land to compare soil properties including soil texture, pH, soil organic carbon (SOC), nitrogen (N), and C:N ratios. Because these sites were identical in all aspects except former cultivation, our approach allowed us to test the hypothesis that cultivation legacies can be detected in the soil today and explore which soil properties most strongly reflect cultivation legacies using discriminant and principal components analyses. Discriminant analysis separated soils between the two land-use conditions with 95% confidence at all four sites. Of the six soil properties, SOC, N, and C:N ratios were most important for distinguishing the cultivation legacies at three sites, whereas soil pH was most important in one site. These results show that soils remain altered in these formerly cultivated sites even after being reseeded, suggesting that future productivity and management will also be affected.     

Relationships of Quality Characteristics with Size‐Exclusion HPLC Chromatogram of Protein Extract in Soft White Winter Wheats

This study investigated relationships between molecular weight distributions of unreduced grain proteins and grain, flour, and end‐use quality characteristics of soft white winter wheats grown in Oregon. Absorbance area and area percentage values of protein fractions separated by size‐exclusion HPLC (SE‐HPLC) showed significant correlations with quality characteristics, indicating associations of molecular weight distributions of proteins with quality characteristics. Specifically, high molecular weight polymeric protein fractions appeared to have a detrimental effect on soft wheat quality. This was shown by significant positive correlations with single kernel hardness index, and mixograph water absorption and tolerance, and negative correlations with break flour yield, cookie diameter, and cake volume. Higher proportions of soluble monomeric protein fraction eluted after the main gliadin peak, were associated with soft wheat quality due to negative associations with single kernel hardness index and mixograph water absorption and tolerance, and positive associations with break flour yield, cookie diameter, and cake volume. Calibration models were developed by the application of multivariate analyses to the SE‐HPLC data. These models explained >90% of the variation in mixograph water absorption and cookie diameter and thickness.     

A Comprehensive Genotype and Environment Assessment of Wheat Grain Ash Content in Oregon and Washington: Analysis of Variation

A comprehensive analysis of the variation in wheat grain ash content has not been previously conducted. This study assessed the relative contribution of genotype and environment to variation in ash content, with a particular aim of ascertaining the potential for manipulating the trait using contemporary adapted germplasm. A total of 2,240 samples were drawn from four years of multilocation field plots grown in the wheat production areas of Oregon and Washington states. Genotypes included commercial cultivars and advanced breeding lines of soft and hard winter, and soft and hard spring wheats with red and white kernel color, several soft white club wheats, and one soft white spring waxy wheat cultivar. In addition to ash, protein content, test weight, and Single Kernel Characterization System kernel hardness, weight and size were also measured. In total, 20 separate fully balanced ANOVA results were conducted. Whole model R² values were highly significant, 0.62–0.91. Nineteen of the 20 ANOVA results indicated significant genotype effects, but the effects were not large. In contrast, environment effects were always highly significant with F values often one to two orders of magnitude larger than the genotype F values. The grand mean for all samples was 1.368% ash. For individual data sets, genotype means across environments varied ≈0.1–0.3% ash. The genotypes judged noteworthy because they had the highest least squares mean ash content were OR9900553 and ClearFirst soft white winter, NuHills hard red winter, Waxy‐Pen and Cataldo soft white spring, and WA8010 and Lochsa hard spring wheats. Genotypes with lowest least squares mean ash were Edwin (club) soft white winter, OR2040073H hard red winter, WA7952 soft white spring, and WA8038 hard spring wheats. In conclusion, wheat grain ash is more greatly influenced by crop year and location than by genotype. However, sufficient genotype variation is present to plausibly manipulate this grain trait through traditional plant breeding.     

Prevalence of Rickettsia species antibodies and Rickettsia species DNA in the blood of cats with and without fever

Rickettsia species antibodies have been detected in some cats but it is unknown whether infected cats develop clinical signs. The prevalence of Rickettsia species deoxyribonucleic acid (DNA) in blood from clinically ill cats has not been determined. The objective of this study was to determine if cats with fever (body temperature >or=102.5 degrees F [39.2 degrees C]) were more likely to have evidence of rickettsial infection than healthy, age-matched, control cats with a body temperature<102.5 degrees F. Rickettsia species polymerase chain reaction (PCR) assays were performed to detect rickettsial DNA extracted from blood (71 paired samples), indirect immunofluorescence assays (IFA) were performed to detect serum antibodies against Rickettsia felis (90 paired samples) and Rickettsia rickettsii (91 paired samples), and the results between pairs were compared. All samples were negative for Rickettsia species DNA. More cats with fever were seropositive for R felis or R rickettsii than control cats, but results were not statistically significant. Results of this pilot study failed to show an association between Rickettsia species DNA or Rickettsia species antibodies and fever.     

Habituation Performance of Two Percids Under Turbid and Clear Water Culture

Advanced walleye (Sander vitreus) and yellow perch (Perca flavescens) fingerlings are produced by habituating pond-reared fingerlings to commercial feed. Success of the habituation phase depends on many variables. Among these, diet contrast/visibility is an important variable for habituation success. The objective of this study was to compare the effect of turbid water (≥100 nephelometric turbidity unit, NTU) and clear water culture conditions during the habituation phase for these two species. In 2005, 12 150 L black-cuboidal tanks with in-tank lighting were stocked at a rate of 2 g/L age 0 of either walleye or yellow perch fingerlings with half of the tanks receiving turbidity (clay slurry) and cultured for 28 d. All fish were fed a commercial diet every 5 min during a 16 h daylight interval at 10%?body weight/d. Walleye in the clear treatment had higher survival (83?±?2.0%) than the turbid treatment (57?±?6.0%). The yellow perch exhibited opposite survival results: turbid treatment rates at 79?±?2.1%?and clear treatment rates at 54?±?9.2%. These results demonstrate that the addition of clay may enhance the contrast of the feed and thus improve the habituation phase for yellow perch.     

Geographical distribution of salmonid alphavirus subtypes in marine farmed Atlantic salmon, Salmo salar L., in Scotland and Ireland

Sequence data from salmonid alphavirus (SAV) strains obtained from farmed marine Atlantic salmon, Salmo salar L. , over a 20-year period between 1991 and 2011 was reviewed to examine the geographical distribution of the genetically defined SAV subtypes in twelve regions across Ireland and Scotland. Of 160 different Atlantic salmon SAV strains examined, 62 belonged to subtype 1, 28 to subtype 2, 34 to subtype 4, 35 to subtype 5 and 1 to subtype 6. SAV subtypes 1, 4 and 6 were found in Ireland, while subtypes 1, 2, 4 and 5 were found in Scotland. In the majority of regions, there was a clear clustering of subtypes, with SAV subtype 1 being the dominant subtype in Ireland overall, as well as in Argyll and Bute in Scotland. SAV subtype 2 predominated in the Shetland and Orkney Islands. The emergence in Atlantic salmon of subtype 2 strains typically associated with sleeping disease in rainbow trout in Argyll and Bute, strongly suggesting transmission of infection between these species, was noted for the first time. SAV subtype 4 was the most common subtype found in the southern Western Isles, while SAV subtype 5 predominated in the northern Western Isles and north-west mainland Scotland. No single strain was dominant on sites in the western Highlands, with a number of sites in this region in particular having more than one subtype detected in different submissions. The significance of these results in relation to aspects of the epidemiology of infection, including transmission, biosecurity and wildlife reservoirs are discussed and knowledge gaps identified.