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Reinhart K.O.,Fort Keogh Livestock and Range Research Laboratory | Anacker B.L.,University of California at Davis
AoB PLANTS | Year: 2014

Neighbouring plants are known to vary from having similar to dissimilar arbuscular mycorrhizal fungal (AMF) communities. One possibility is that closely related plants have more similar AMF communities than more distantly related plants, an indication of phylogenetic host specificity. Here, we investigated the structure of AMF communities among dominant grassland plants at three sites in the Northern Great Plains to test whether the pairwise phylogenetic distance among plant species was correlated with pairwise AMF community dissimilarity. For eight dominant and co-occurring grassland plant species, we reconstructed a phylogeny based on DNA data and characterized the AMF communities of their roots at each site. Community analyses revealed that AMF communities varied among sites and among plant species. Contrary to expectations for phylogenetic host specificity, we found that within a site more closely related plants had more distinct AMF communities despite their having similar phenologies. Associations with unique AMF communities may enhance the functional complementarity of related species and promote their coexistence.


Waterman R.C.,Fort Keogh Livestock and Range Research Laboratory | Richardson K.D.,New Mexico State University | Lodge-Ivey S.L.,New Mexico State University
Journal of the Science of Food and Agriculture | Year: 2011

Background: Euphorbia esula L. (leafy spurge) is indigenous to Eurasia and has been known to cause grazing aversion in ruminant species. As a result, E. esula encroachment has negatively impacted rangelands in the Northern Great Plains and Intermountain West of the USA, as well as southern Canada. Our objectives were to evaluate the effect of increasing concentrations of E. esula on in vitro dry matter digestibility (DMD) and gas production. Two ruminally-cannulated cows and ewes were used as rumen inoculum donors. To accomplish objectives, two studies were conducted. In study 1, animals were fed exclusively a barley hay (12% crude protein (CP), 55.4% neutral detergent fiber (NDF), DM basis) diet; whereas in study 2, animals were fed a diet of 15% E. esula (21.9% CP, 48% NDF, DM basis) and 85% barley hay based on previous day intake. Results: The 24 and 48 h in vitro and 96 h gas production indicate that, regardless of inoculum source or substrate fermented, DMD was not influenced. Differences, however, were consistently observed across studies for NDF disappearance. Conclusion: Regardless of inoculum source NDF disappearance was greater when substrate being fermented contained 0%, 80%, or 100% E. esula. Published 2011 by John Wiley & Sons, Ltd.


Reinhart K.O.,Fort Keogh Livestock and Range Research Laboratory | Van Der Putten W.H.,Netherlands Institute of Ecology | Van Der Putten W.H.,Wageningen University | Tytgat T.,Radboud University Nijmegen | Clay K.,Indiana University Bloomington
International Journal of Ecology | Year: 2011

Existing theory for invasive nonnative species emphasizes the role of escaping specialist enemies. A useful approach is to reciprocally transplant enemies in a controlled and common experiment to quantify the interaction specificity of enemies from plant's native and nonnative ranges. Quantitative measures of interaction specificity, from two experiments with three host genotypes (Belgium, Louisiana, and Pennsylvania) and 37 Pythium isolates (10 Europe and 27 USA), revealed that Pythium pathogens from populations of Prunus serotina in its native range were not host genotype specific while Pythium pathogens from its nonnative range vary with host genotype. This study provides empirical evidence suggesting that Pythium from the nonnative range are either preadapted to or are actively adapting to this host. Although only for a single pathosystem, this study illustrates the importance of understanding enemy impact and host-specificity to assess whether an invader has escaped its natural enemies. Copyright © 2011 Kurt O. Reinhart et al.


Reinhart K.O.,Fort Keogh Livestock and Range Research Laboratory | Reinhart K.O.,Indiana University Bloomington | Tytgat T.,Netherlands Institute of Ecology | Tytgat T.,Wageningen University | And 3 more authors.
New Phytologist | Year: 2010

Globally, exotic invaders threaten biodiversity and ecosystem function. Studies often report that invading plants are less affected by enemies in their invaded vs home ranges, but few studies have investigated the underlying mechanisms. Here, we investigated the variation in prevalence, species composition and virulence of soil-borne Pythium pathogens associated with the tree Prunus serotina in its native US and non-native European ranges by culturing, DNA sequencing and controlled pathogenicity trials. Two controlled pathogenicity experiments showed that Pythium pathogens from the native range caused 38-462% more root rot and 80-583% more seedling mortality, and 19-45% less biomass production than Pythium from the non-native range. DNA sequencing indicated that the most virulent Pythium taxa were sampled only from the native range. The greater virulence of Pythium sampled from the native range therefore corresponded to shifts in species composition across ranges rather than variation within a common Pythium species. Prunus serotina still encounters Pythium in its non-native range but encounters less virulent taxa. Elucidating patterns of enemy virulence in native and non-native ranges adds to our understanding of how invasive plants escape disease. More-over, this strategy may identify resident enemies in the non-native range that could be used to manage invasive plants. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).


Reinhart K.O.,Fort Keogh Livestock and Range Research Laboratory | Nichols K.A.,Northern Great Plains Research Laboratory | Nichols K.A.,Rodale Institute | Petersen M.,Fort Keogh Livestock and Range Research Laboratory | Vermeire L.T.,Fort Keogh Livestock and Range Research Laboratory
Ecosphere | Year: 2015

We estimate rangeland managers assessing ecosystem health have measured soil stability .800,000 times. Our aim was to use quantitative data from a site in the Northern Great Plains, USA and asemi-quantitative literature search to demonstrate the robustness of soil stability as an indicator of ecosystem functioning. Empirical data included measurements of plant and soil properties along a locallivestock grazing gradient to determine whether soil stability (e.g., % water-stable aggregates) explained primary productivity and soil water transport for a mixed-grass prairie site in the Northern Great Plains. We measured: annual net primary productivity (ANPP), elevation, % soil moisture, measures of soil stability, and soil water transport (field-saturated infiltrability and sorptivity) across points spanning a localgradient in livestock grazing intensity (none vs. light to moderate stocking rates; mean distance separating points=39.9 m [range=5.2-71.3 m]). Across the sampled gradient, variation in ANPP was best explainedby a model with field-saturated infiltrability and % soil moisture. Infiltrability explained slightly more of the variation. We then determined that moderate amounts of variation in infiltrability were explained byANPP, % soil moisture, and % water-stable aggregates. We determined that most of this variation was explained by ANPP and then soil moisture. Our empirical findings indicate that plant production wascorrelated with infiltration though we could not determine whether variation in plant production was caused by variation in infiltration or vice versa.We generally failed to show that soil stability (e.g., % waterstableaggregates) was a useful predictor of primary productivity and soil water transport. Our semiquantitative literature review also indicated that soil stability was not a consistent predictor of either plantproduction or infiltration. The varying evidence reported here on whether soil stability is a predictor of ecosystem function illustrates the difficulty in identifying an indicator of ecosystem health that (1) is apredictor of ecosystem function across grassland types, (2) is sensitive to rangeland management, and (3) can be easily implemented by non-experts. Copyright: © 2015 Reinhart et al.


Daniels T.F.,Washington State University | Wu X.-L.,University of Wisconsin - Madison | Pan Z.,Washington State University | Michal J.J.,Washington State University | And 4 more authors.
PLoS ONE | Year: 2010

In the present study, thirteen genes involved in the reverse cholesterol transport (RCT) pathway were investigated for their associations with three fat depositions, eight fatty acid compositions and two growth-related phenotypes in a Wagyu x Limousin reference population, including 6 F1 bulls, 113 F1 dams, and 246 F2 progeny. A total of 37 amplicons were used to screen single nucleotide polymorphisms (SNPs) on 6 F1 bulls. Among 36 SNPs detected in 11 of these 13 genes, 19 were selected for genotyping by the Sequenom assay design on all F2 progeny. Single-marker analysis revealed seven SNPs in ATP binding cassette A1, apolipoproteins A1, B and E, phospholipid transfer protein and paraoxinase 1 genes significantly associated with nine phenotypes (P<0.05). Previously, we reported genetic networks associated with 19 complex phenotypes based on a total of 138 genetic polymorphisms derived from 71 known functional genes. Therefore, after Bonferroni correction, these significant (adjusted P<0.05) and suggestive (adjusted P<0.10) associations were then used to identify genetic networks related to the RCT pathway. Multiple-marker analysis suggested possible genetic networks involving the RCT pathway for kidney-pelvic-heart fat percentage, rib-eye area, and subcutaneous fat depth phenotypes with markers derived from paraoxinase 1, apolipoproteins A1 and E, respectively. The present study confirmed that genes involved in cholesterol homeostasis are useful targets for investigating obesity in humans as well as for improving meat quality phenotypes in a livestock production.

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