Soybean is an excellent source of plant protein. To provide a higher quality meal product, soybean producers desire to improve soybean nutritional profiles. Quantitative trait loci (QTL) mapping can identify markers associated with variation in seed protein and seed oil concentration, and confirmation of QTL is crucial to improving the efficacy of marker-assisted selection (MAS). The objectives of this study were to identify QTL for seed protein and seed oil concentration in a relevant genetic pedigree of the cross ‘Essex × Williams 82’ recombinant inbred line (RIL) population. A total of 302 RIL and 12,730 SNP markers were used to identify QTL-controlling seed quality traits. Novel QTL were identified, and validation tests for loci detected in the earlier generation RIL were performed. Seed protein and seed oil concentration had high heritability across multiple environments but were negatively correlated (r = −0.69, p < 0.05). Genotype and genotype × environment interaction was significant (p < 0.05) for seed protein and seed oil concentration. The study references data from a previous year in one location and focuses on a one-year study of the population in three locations. A total of 27 QTL for protein and oil were detected. The QTL explained 3.1–9.8% of the variation in seed protein concentration and 3.2–14.1% of the variation in seed oil concentration. Several QTL were confirmed, and a protein QTL for consideration as a technically confirmed QTL was located on Gm 7 in the genome.

Partial least squares (PLS) is a statistical technique that can evaluate the association of large numbers of external environmental variables with biological responses. PLS is a good method for analyzing the relative importance of variables and compressing the data for regression analyses. The objective of this study was to use PLS and regression analyses on soybean (Glycine max L.) and maize (Zea mays L.) variety trial results for five (soybean) or three (maize) maturity group (MG) tests, at five Tennessee locations spanning 14 years, in order to determine the environmental effects (weekly minimum and maximum air temperature and precipitation) on the expression of yield genetic variance (Vg). Overall, PLS excelled at identifying combinations of weather variables to develop models with high R2 values (41–59%) relative to the regression analysis (R2 = 34–44%), but they did not address the effects of specific variables as in regression analysis. In both maize and soybean, differences in genetic variance occurred among MG tests and locations. Overall, precipitation was the driving variable for maize Vg, indicating maize is more sensitive to rain events during the growing season than soybean, i.e., with each cm of precipitation, maize Vg increased by 11.38–23.78 (Mg ha−1)2. The results suggest that ensuring adequate water, particularly during weeks 3 and 6, is critical for maize Vg, regardless of the MG test and location. Genetically modified soybean cultivars responded similarly to conventional cultivars, suggesting no Vg response differences due to the glyphosate tolerance trait. These results have important implications for irrigation timing for the maximum expression of genetic differences in maize and soybean cultivars, particularly for management planning during future stochastic weather events.

Evidence for the importance of seedling morphology and the benefits of multi-cropping in tree plantations continues to increase worldwide. The effects of seedling form on the performance of multi-cropped and monoculture plantings of northern red oak and shortleaf pine seedlings were quantified to test the hypotheses that: (1) multi-cropping northern red oak and shortleaf pine seedlings would lead to increased survival and growth of these species, and (2) that the productivity and overall success of mixed oak-pine plantations can be influenced by seedling morphology. Four different form classes of 1–0, bareroot northern red oak seedlings (Short:Thin, Short:Thick, Tall:Thin, and Tall:Thick) were planted with 1–0, bareroot shortleaf pine seedlings at a 2.44 m spacing, with 0.31 m between each planted oak and pine. Adjacent monocultures of shortleaf pine and all form classes of northern red oak were also planted for comparison. Measurements of seedling performance over six years revealed no significant differences in shortleaf pine and northern red oak survival and growth among multi-cropped and monoculture treatments. In contrast, mean height and mean basal diameter in Tall:Thick northern red oak seedlings were significantly greater than in the remaining three northern red oak form classes, regardless of multi-cropping treatment. Survival did not differ among form classes ( p > 0.05). These results suggest that seedling morphology was more important than the effects of multi-cropping early on in the development of these plantations, and that further testing of the effects of form class across different multi-cropped species is warranted.

The American chestnut (Castanea dentata) is imperiled due primarily to two diseases caused by nonnative pathogens, notably chestnut blight and Phytophthora root rot (PRR) caused by Cryphonectria parasitica and Phytophthora cinnamomi, respectively. Field reintroduction trials are important to test trees bred for blight resistance under forest conditions to quantify survival and field performance in managed stands that represent future restoration sites. We planted 513 pedigreed bare-root (1-0) nursery seedlings into an even-aged regeneration harvest in the Blue Ridge Mountains of eastern Tennessee, USA to test effects of breeding, genetics, and seedling size class on field performance, including survival, total growth, incremental growth (a measure of growth efficiency), and height growth patterns. Mortality was highest in the first two years after planting, and PRR symptoms coupled with soil and root assays that tested positive for P. cinnamomi suggested this disease was a significant contributor to mortality. Chinese chestnut (C. mollissima), known to be resistant to P. cinnamomi and C. parasitica, had the highest survival (96 percent) compared to American chestnut (34 percent) and hybrid generations, including the BC3F3 generation (41 percent). Less advanced hybrid generations, such as the BC1F3 and BC2F3, had the greatest total height and ground-line diameter (GLD) and height growth efficiencies. BC3F3 generation seedlings were associated with higher-than-expected rates of nominal height growth patterns (i.e., flat growth rates over time or early mortality) compared to Chinese chestnut seedlings. Results, however, indicated the breeding program was successfully integrating desired American chestnut growth traits into the hybrid genome while transferring an intermediate level of resistance from the Chinese chestnut. We identified superior and inferior BC3F3 families that can help inform breeding and restoration efforts. Visually grading seedlings before planting affected survival and growth of generations and genetic families differently, indicating that refinement of nursery production and restoration plantings should consider genetic effects. Across generations, seedling size grading improved total height and GLD growth that would save resources necessary for competition control and animal browsing protection, but large-size seedlings also exhibited lower C. parasitica resistance rankings over time, probably owing to earlier bark fissuring. PRR probably affected outcomes, particularly for hybrid and American chestnut seedlings that have very low levels of P. cinnamomi resistance. Managers could expect advanced breeding generations to perform similarly to American chestnut in growth through the critical stage of early stand development. More durable resistance to C. parasitica and mitigation of PRR through better site selection and/or resistance screening will improve future restoration efforts.

The loss of Fagaceae species is an increasing concern globally, including in North American where American chestnut (Castanea dentata) has been virtually eliminated by non-native pathogens, and oaks (Quercus) are experiencing widespread regeneration failures and declines. Tree improvement and breeding programs are producing trees for disease resistance or improved performance traits but require field testing to refine efforts. We established a study in 2015 on a xeric pitch pine (Pinus rigida) site in the Blue Ridge Mountains of North Carolina to regenerate American chestnut and interspecies hybrids (BC3F3) and the co-occurring species of white oak (Q. alba) through planting bare-root, quality-graded seedlings. Chinese chestnut (C. mollissima) was also tested as a control species. We used pedigreed seed sources from open-pollinated genetic families that were nursery grown (1-0 bareroot seedlings for chestnut, 2-0 bareroot seedlings for white oak) to maximize overall size and competitive ability. Though there was variability within and among plant families in performance, American chestnut and BC3F3 hybrids generally outperformed Chinese chestnut (at least 13 % taller) and white oak (at least 29 % taller) for the first three years, but intraspecies differences among genetic families were significant for nearly all traits tested. Initial seedling root morphology poorly explained field performance (R2 < 0.17), but this relationship was significant for both white oak families and the only northern BC3F3 seed source. American chestnuts and BC3F3 hybrids had higher stem height to ground diameter ratios compared to white oak (at least 11 % greater), indicating that white oak likely concentrates more resources to root development while chestnut concentrates more resources to maintaining above-ground competitive advantages. Additionally, we investigated soil fungal communities, both pre-and post-tree establishment and tested if these fungal commu-nities can be used to predict plant performance or health. Soil fungi did a poor job predicting plant performance. Our results indicate that co-occurring Fagaceae species can be established in restoration plantings using well developed quality seedlings on relatively xeric sites. Managers should use diverse seed sources to avoid planting poor performing families and expect that chestnuts bred for blight resistance will outcompete planted white oak, at least in the short-term.

Climate extremes pose a global threat to crop security. Conservation agriculture is expected to offer substantial climate adaptation benefits. However, synergistic effects of conservation practices on yield during normal versus extreme climates and underlying regulatory mechanisms remain elusive. Here, we analyze 29-years of climate data, cotton (Gossypium hirsutum L.) yield, and soil data under 32 management practices in Tennessee, USA. We find that long-term no-tillage enhanced agroecosystem resilience and yield stability under climate extremes and maximized yield under favorable climate. We demonstrate that no-tillage benefits are tied with enhanced soil structural stability and organic carbon. No-tillage enhanced the effectiveness of legume cover crop in stabilizing cotton yield during relatively dry or wet, and dry years, while nitrogen fertilizer rate and precipitation timing, controlled yield stability in wetter years. Our findings provide evidence-based insights into how management strategies can enhance agroecosystem resilience and production stability in climate extremes. Long-term no-tillage systems enhance cotton yield resilience to climate extremes through improved soil quality in Tennessee, USA, according to a 29-year rain-fed plot-scale cotton experiment.

Abstract The Soil Management Assessment Framework (SMAF) may provide insight into how conservation practices affect soil quality (SQ) regionally. Therefore, we aimed to quantify SQ in a long‐term (15‐yr) crop rotation and bio‐covers experiment under no‐tillage using SMAF. Main effects were cropping rotations of soybean [Glycine max (L.) Merr.], corn (Zea mays L.), and cotton (Gossypium hirsutum L.). Split‐block bio‐cover treatments consisted of winter wheat (Triticum aestivum L.), Austrian winter pea (Pisum sativum L. sativum var. arvense), hairy vetch (Vicia villosa Roth), poultry litter, and fallow (control). Seven SQ indicators—soil pH, total organic carbon (TOC), bulk density (BD), soil extractable P and K, electrical conductivity (EC), and sodium adsorption ration (SAR)—were scored using SMAF algorithms, and investigated individually and as an overall soil quality index (SQI). Simple linear regressions were performed between SQI and crop yields. Differences (p < .05) in SQI within rotations varied when analyzed across and by depth. Overall, cotton–corn and/or continuous corn had greater SQI than soybean‐based rotations. Poultry litter had the greatest TOC, pH, K, and BD scores at the 0‐ to 15‐cm soil depth, and the lowest SQI. Reductions in SQI within bio‐covers were linked to P scores. A positive relationship was found between SQI and cotton yield at the 15‐ to 30‐cm soil depth (R2 = .48; p < .05). Investigating SMAF scores individually and separately per depth addresses the effects of long‐term conservation practices on SQ. Overall, SMAF can be used to develop best management practices and nutrient management strategies.

Continuous, season-long (May-August) grazing is the most commonly used grazing strategy among tall fescue [Lolium arundinaceum (Schreb.) Darbysh.] belt beef (Bos taurus) producers. However, little information is available regarding the feasibility of managing native warm-season grass (NWSG) pastures in this region with continuous, season-long grazing. We compared stand sustainability, beef cattle performance, and pasture production between continuous (CONT), season-long grazing and heavy-early (HEAVY), a modified continuous grazing strategy, on mixed-NWSG pastures. Heavy-early was designed to match the growth curve of NWSG, with an initial stocking target of 1.25 times the CONT density until 25 June, at which time stocking was reduced to 0.75 times the CONT density. Pastures were mixed big bluestem (Andropogon gerardii Vitman), indiangrass [Sorghastrum nutans (L.) Nash], and little bluestem [Schizachyrium scoparium (Michx.)]. The plant population (plants m(-2)) was similar between treatments, but years differed (P < .001), with a 35% reduction from 2017, the third and final year of grazing, to 2018. Despite the decline in plant density, overall tiller density (tillers m(-2)) increased 14%, indicating that the grazing strategies were likely sustainable. The grazing strategies had similar (P > .05) average daily gain (ADG; kg d(-1)), animal-days ha(-1), and total gain (kg ha(-1)). Weaned steer ADG was 0.98 kg d(-1) for CONT and 0.89 kg d(-1) for HEAVY. Total gain was 379 kg ha(-1) for CONT and 334 kg ha(-1) for HEAVY. Continuous grazing appears to be an appropriate strategy for managing NWSG pastures in the Fescue Belt.

It is important for yield test sites to elicit differences among genotypes, minimize redundancy of performance information, and generate a genotype x environment interaction representative of the targeted region. The objective of this study was to use corn (Zea mays L.) variety trial data from three relative maturity group (MG) tests (early, medium, and late) at five Tennessee locations spanning 14 yr to compare test location uniqueness and redundancy via genetic variance estimates and cluster analysis. Principle component analyses allowed for location comparisons of genetic variance expression among cultivars in different MG tests. Individual location-test-year genetic variance estimates ranged from <1 to 584 (Mg ha(-1))(2). Years and locations affected the magnitude of genetic variance, with years largely driving genetic expression within MGs in these environments. However, the late MG consistently had the greatest variance estimates. Across 14 yr, there was minimum duplicative information provided across the five yield test sites. Consequently, all locations were needed and none could be eliminated without compromising cultivar yield trial information for the three MG tests. Correlations between mean yields and genetic variance showed a weak relationship across locations (environments), years, and MG tests (r = .021); thus, high-yielding environments did not correspond with increased genetic variance expression. These types of analyses are useful for evaluating the discriminating ability and duplicative or correlated expression of genetic information across locations for robust variety trials within and across maturity groups and targeted regions.

Gut microbial enzymes, bile salt hydrolases (BSHs) are the gateway enzymes for bile acid (BA) modification in the gut. This activity is a promising target for developing innovative non-antibiotic growth promoters to enhance animal production and health. Compelling evidence has shown that inhibition of BSH activity should enhance weight gain by altering the BA pool, host signalling and lipid metabolism. We recently identified a panel of promising BSH inhibitors. Here, we address the potential of them as alternative, effective, non-antibiotic feed additives, for commercial application, to promote animal growth using a chicken model. In this study, the in vivo efficacy of three BSH inhibitors (caffeic acid phenethylester, riboflavin, carnosic acid) were evaluated. 7-day old chicks (10 birds/group) were either untreated or they received one of the specific BSH inhibitors (25 mg/kg body weight) via oral gavage for 17 days. The chicks in treatment groups consistently displayed higher body weight gain than the untreated chicks. Metabolomic analysis demonstrated that BSH inhibitor treatment led to significant changes in both circulating and intestinal BA signatures in support of blunted intestinal BSH activity. Consistent with this finding, liver and intestinal tissue RNA-Seq analysis showed that carnosic acid treatment significantly altered expression of genes involved in lipid and bile acid metabolism. Taken together, this study validates microbial BSH activity inhibition as an alternative target and strategy to antibiotic treatment for animal growth promotion.

Main considerations for yield trial site selection are the ability to discriminate among genotypes, minimize redundancy, and generate a genotype x environment interaction representative of the targeted market region. The objective was to utilize soybean (Glycine max L.) variety trial results of five relative maturity group (MG) tests at five Tennessee locations spanning 14 yr to compare test location uniqueness and/or redundancy via genetic variance estimates (estimated as twice the genetic variance among homozygous lines) and cluster analysis. Principle components analyses allowed for location comparisons of genetic variance expression among cultivars in different MG tests. Individual location, test, and year genetic variance estimates ranged from < 1-285 (Mg ha(-1))(2). Years and locations affected the magnitude of genetic variance, with years largely driving genetic expression within MGs in these environments. Location-induced effects were likely owing to different MGs experiencing soil moisture and temperature (day and nighttime) at varying maturity stages. Within a given location, the magnitudes of genetic variance estimates were similar among the five MGs, illustrating that glyphosate-tolerant and nontolerant cultivars had similar genetic variability. There were three sets of three locations that consistently provided nonredundant genetic expression, with two locations being duplicative. These results indicate that four of the five locations are needed, and one location could be eliminated without compromising cultivar yield trial information for five MG tests. Such analyses are worthwhile for comparing yield trial locations for their discriminating ability and representativeness that are essential for a robust variety test program within a targeted region.

Abstract Eleven switchgrass cultivars (eight ornamental and three agronomic) were inoculated with 40 switchgrass rust isolates collected from the southeastern U.S. to study host resistance, rust virulence and host/pathogen interactions by measuring urediniospore germination percentage, latent period, and the number of uredia and urediniospores produced per cm2 of leaf surface. In general, ornamental switchgrass cultivars had reduced number of uredia and urediniospores produced per cm2 than did agronomic cultivars. Rust isolates were variable for virulence in culture (on grass blades in petri dishes); however they could not be segregated into groups based on collection locations or years. The results of this study will provide information concerning durable horizontal resistance in switchgrass for the ornamental industry. Index words:, Switchgrass, leaf rust, resistance. Species used in the study: switchgrass (Panicum virgatum L., rust (Puccinia emaculata).

Endotoxaemia is one of the most severe and ubiquitous disease processes in horses; and delayed gastric emptying is one of the most clinically significant manifestations of endotoxaemia. Current information suggests that oxidative damage plays a key role in the systemic effects induced by endotoxin and this raises the possibility that antioxidants, such as dimethyl sulfoxide (DMSO), might have a protective effect. No study has yet evaluated the efficacy of DMSO in ameliorating delayed gastric emptying caused by endotoxaemia in horses. We hypothesized that DMSO would ameliorate delayed gastric emptying caused by intravenous lipopolysaccharide (LPS) administration. Horses were randomly assigned to one of 4 groups; of 6 horses each: Normosol (Abbott Laboratories, Abbott Park, Illinois, USA) + LPS (0.2 mu g/kg bwt, i.v.); DMSO (1g/kg bwt, i.v.) + Saline; High-dose DMSO (1g/kg bwt, i.v.) + LPS; Low-dose DMSO (20 mg/kg bwt, i.v.) + LPS. All horses in all groups received acetaminophen (20 mg/kg reconstituted in one liter of warm tap water) by nasogastric intubation. Data for acetaminophen concentrations in the blood as a measure of gastric emptying were examined for the effect of treatment using a repeated-measures mixed-model ANOVA. A value of P < 0.05 was considered significant. Delayed gastric emptying occurred in all horses receiving LPS, as indicated by the lower concentrations of acetaminophen in these groups along the study period. DMSO did not ameliorate the effect of LPS on gastric emptying. Low-dose DMSO actually exacerbated the LPS-induced delay in gastric emptying. In this study, DMSO did not have any protective effect against LPS-induced delayed gastric emptying in horses.

In subhumid Southeastern USA, rapid decomposition of initially low cotton residue limits the benefits of no-tillage system in regard to the soil quality. Long-term addition of cover crops may compensate the low cotton residue and further improve the soil physical quality under no-tillage system. We examined the long-term (34 yr) effect of two cover crop species, hairy vetch (Vicia villosa), and winter wheat (Triticum aestivum L.), and no cover crop, applied on conventional tillage and no-tillage on soil hydro-physical properties and cotton yield. Research was conducted on a Lexington silt loam in Jackson, TN, during 2015 and 2016. Soil physical properties including bulk density, cone penetration resistance, in-situ soil moisture content, wet aggregate stability, water infiltration and field-saturated hydraulic conductivity, soil water retention characteristics, and dry aggregate size distribution were measured. Bulk density assessed before the annual tillage did not differ significantly between no-tillage and conventional tillage systems. Cone penetration resistance showed a greater horizontal consistency of maximally resistant zones (> 2 MPa) under tilled managements, indicating a possible presence of a plow pan immediately below the plowed soil layer. Differences in field soil moisture content among tillage and cover crops were more evident in drier periods of the growing seasons, resulting in 28.6% and 36.4% greater moisture content in vetch cover crop and no-tillage than no cover crop and conventional tillage, respectively. No-tillage and vetch cover crop also increased the wet aggregate stability by 13% at 0-15 cm. Results showed a significant tillage x cover crop interaction in soil hydraulic properties. Our result demonstrates that long-term incorporation of cover crops, particularly vetch with no-tillage, significantly improved the initial infiltration rate, cumulative infiltration, and field-saturated hydraulic conductivity and increased the mean weight diameter of aggregates by promoting the macroaggregation. Improvement in soil physical properties was associated with an increase in cotton lint yield under cover crop and no-tillage management.

The loss of American chestnut (Castanea dentata) in eastern North America to chestnut blight, a disease caused by the fungal pathogen (Cryphonectria parasitica), has devastated ecological and utilitarian processes and functions. A backcross breeding approach has been developed to confer disease resistance to hybrid seedlings, and forest reintroduction trials will provide important information on performance and durability of resistance in real-world forest conditions. Three plantings were established in 2009 in mesic, even-aged regeneration harvests (site index averaged 23 m for Quercus rubra) and were examined for eight-year blight resistance. These plantings are the first forest field trials to test blight resistance of the most advanced breeding generation currently available, the third generation of the third backcross (BC3F3), against less advanced breeding generations (BC1F3, BC2F3), disease-resistant Chinese chestnut (C. mollissima), and disease-susceptible American chestnut. We also examined if C. parasitica infection was related to tree size and growth. The pathogen infected 36 percent of trees across locations by year 8, but 31 percent of trees died prior to detection of infection. Non-pathogen related mortality was probably due to factors that are typical of hardwood plantings, including repeated deer browsing and native and non-native pest damage. The BC3F3 generation exhibited resistance more similar to the Chinese chestnut than the American chestnut, but exhibited significantly lower resistance than Chinese chestnut at the location with the highest blight incidence; genetic family differences among BC3F3 progeny were significant at this location. Interactions between planting location and breeding generation affected resistance rankings, suggesting additional or longer-term testing is needed to determine resistance of a particular breeding line across a variety of sites. Probability of disease incidence was positively related to ground-line diameter (GLD), but this relationship depended on location and breeding type. At two locations, American chestnut had 50 percent probability of C. parasitica infection when GLD was approximately 70 mm, and the BC3F3 had 50 percent probability when GLD was between 93 and 126 mm. The Chinese chestnut maintained low probability of disease incidence (< 35 percent) across all GLD sizes, regardless of location. While a relatively high level of disease resistance was associated with the most advanced breeding generation, BC3F3, the plantings are too young to determine durable blight resistance.

Incorporation of cover crops in no-tillage (NT) cropping systems can be constrained by economic and climatic barriers. In such condition, region-specific crop rotations can diversify and increase biomass input and improve soil quality. We aimed to evaluate the 15-yr impact of six cropping systems including corn-corn (Zea mays L.) (CC), soybean-soybean [Glycine max (L.) Merr.] (SS), cotton-cotton (Gossypium hirsutum L.) (TT), corn-soybean (CS), cotton-corn (TC), and soybean-cotton (ST) on soil hydro-physical properties and yield on a no-till system. Study was conducted on a Loring silt loam (fine-silty, mixed, active, thermic Oxyaquic Fragiudalfs) at Milan, TN. Incorporation of cotton in the cropping system increased near-surface penetration resistance by 17%. Field soil moisture during dry periods (θvd) was 18% greater in corn-soybean and continuous corn than other cropping systems. Including corn in cropping system also increased the wet aggregates stability (WAS) in the top 15cm and geometric mean diameter (GMD) in the top 30cm. Among all treatments, corn-soybean resulted in the greatest field-saturated hydraulic conductivity (Kfs=25.2cmday−1), cumulative infiltration after 200min (I=114mm), and plant-available water content (PAWC=0.20cm3cm−3). However, mean values were only different (p<0.05) between corn-soybean and cotton cropping systems. In accordance with the soil properties, the corn-soybean produced the greatest corn (10Mgha−1) and soybean (3.1Mgha−1) among all treatments. The cotton-corn rotation, despite showing a non-significant advantage in most soil physical properties over other cotton cropping systems, except for greater macroaggregation, produced 13% and 37% greater cotton yield than continuous cotton and soybean-cotton, respectively. Regression analysis indicated the large water retention capacity (θvd and PAWC) as the common characteristics of large corn and soybean yielding cropping systems. Overall, the inclusion of corn in double crop rotations with soybean and cotton improved soil hydro-physical quality and/or yield. Continuous corn improved soil structure and did not negatively affect the corn yield.

Evaluating different breeding selection strategies for relative utility is necessary to choose those that maximize efficiency. Soybean [ Glycine max (L.) Merr.] seed yield and fatty acid, protein, and oil contents are all commercially important traits that display complex quantitative inheritance. A soybean population consisting of 860 F 5 –derived recombinant inbred lines (RILs), genotyped with 4867 polymorphic single nucleotide polymorphism (SNPs) was used to compare phenotypic and context specific genomic selection (GS) strategies. To simulate progeny rows, each RIL was grown in a single plot in 2010 in Knoxville, TN, and phenotype was recorded. A subset of 276 RILs with similar maturity was then grown in multilocation, replicated field trials in 2013 to compare the performance of each selection method in field conditions. Notably, the preferred method for each trait was GS. Of the GS approaches evaluated, Epistacy performed best for yield, and BayesB and/or genomic best linear unbiased prediction (G‐BLUP) were preferred for each of the other traits. Yield was the only trait for which the predictions had a large change when the number of SNPs and the number of RILs were randomly reduced for the G‐BLUP model, with the best predictions occurring when RILs with different maturity that were not grown in 2013 were removed from the training set. These findings provide important information on how soybean breeders can maximize selections from the progeny row stage for yield and fatty acid, protein, and oil contents by using appropriate selection strategies.

Human activity has extensively transformed the land surface by agricultural intensification and urbanization. In soil, nematodes are the most abundant invertebrates. The effect of human interventions was assessed on overall richness, overall abundance, richness and abundance of nematodes of each trophic group and colonizer-persister (c-p) guild by comparing urban, agriculture and disturbed grassland (DGL) with natural grassland (NGL) and forest ecosystems. Meta-analyses were conducted to generate quantitative summaries from 111 published articles that met the inclusion criteria, 91 expressed data in grams and 20 expressed data in cm(3). Results from data expressed per 100 g of soil indicated that overall richness was higher in forest than in NGL, DGL, urban, and agriculture ecosystems. The richness of all c-p guilds and of all trophic groups except herbivores was highest in forest ecosystems. In contrast, overall abundance was highest in DGL, agriculture and forest ecosystems. The abundance of c-p 1, c-p 2 and c-p 3 guilds and bacterivores, fungivores and herbivores was highest in disturbed ecosystems, while the abundance of c-p 4 and c-p 5 guilds and predators and omnivores was highest in relatively undisturbed ecosystems. Results from data expressed as nematodes per 100 cm3 of soil indicated that abundance followed a similar pattern, but richness often differed between the two methodologies. These meta-analyses strengthen the concept that human interventions adversely impact both richness and abundance using nematodes as soil health bioindicators.

Switchgrass, a leading candidate for lignocellulosic bioenergy feedstock development in the USA, has received widespread researchers' attention in the recent years. For switchgrass to be an economical alternative to fossil fuels, significant biological and technological advancements have to be accomplished primarily in genetic improvement of biomass and ethanol yields.