A robust set of black walnut microsatellites for parentage and clonal identification     

Rodney L. Robichaud  Jeffrey C. Glaubitz  Olin E. Rhodes Jr.  Keith Woeste 《New Forests》2006,32(2):179-196

We describe the development of a robust and powerful suite of 12 microsatellite marker loci for use in genetic investigations of black walnut and related species. These 12 loci were chosen from a set of 17 candidate loci used to genotype 222 trees sampled from a 38-year-old black walnut progeny test. The 222 genotypes represent a sampling from the broad geographic distribution of the species. Analysis of the samples using the 12 loci revealed an average expected heterozygosity of 0.83, a combined probability of identity of 3×10⁻¹⁹, and a combined probability of exclusion for paternity analysis of >0.999. The 222 genotyped trees from the progeny test comprised 39 open-pollinated families, 29 of which (having at least five sampled progeny) were used to estimate the outcrossing rate for the progeny trial. The same 29 families were used to construct a Neighbor-Joining dendrogram based upon allele sharing between individuals. The multilocus estimate of the outcrossing rate was 100% (standard error of zero), higher than the 90% level found in previous studies at the embryo stage, suggesting that both artificial and natural selection against selfs may have occurred over the 38-year lifespan of the progeny trial. In the Neighbor-Joining dendrogram, the majority of the putative siblings grouped together in 21 out of the 29 families, showing that the microsatellites were able to discern most of the family structure in the dataset. Our results indicate that errors were sometimes committed during the establishment of the progeny test. This set of microsatellite loci clearly provides a powerful tool for future applications in black walnut.  相似文献   

Detecting endotoxin activity in bovine serum using an automated testing system     

Kazuyuki SUZUKI  Toshio SHIMAMORI  Ayano SATO  Kenji TSUKANO  Masakazu TSUCHIYA  Jeffrey LAKRITZ 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(8):977-979

The aim of the present study was to compare the ability of the commercially available portable test system (PTS^TM) to detect endotoxin activity in bovine serum, with that of the traditional LAL-kinetic turbidimetric (KT) and chromogenic (KC) assays. Prior to testing, serum samples, which were obtained from endotoxin-challenged cattle, were diluted 1:20 in endotoxin-free water and heated to 80°C for 10 min. The performance of the PTS^TM was not significantly different from that of the traditional LAL-based assays. The results using PTS^TM correlated with those using KT (r²=0.963, P<0.001) or KC assays (r²=0.982, P<0.001). Based on these findings, the PTS^TM could be applied as a simplified system to assess endotoxin activity in bovine serum.  相似文献   

Heritability of Latent Period Estimated from Wild-Type and Selected Populations of Puccinia triticina     

Lehman JS  Shaner G 《Phytopathology》2007,97(8):1022-1029

ABSTRACT Durability of partially resistant wheat cultivars to wheat leaf rust depends on the amount of genetic variation in parasitic fitness within populations of the pathogen Puccinia triticina. To assess the durability of partial resistance, selection experiments were used to explore quantitative variation in parasitic fitness of P. triticina. Fungal populations 881-WT and 882-WT were selected for shortened latent period on partially resistant cvs. CI 13277 and Sw 72469-6 for multiple generations. Fitness components were measured for wild-type and selected fungal populations. Responses to selection and selection differentials were calculated, and broad-sense, realized heritabilities for latent period were estimated for wild-type fungal populations on CI 13227 and on Sw 72469-6. Selected populations had fitness characteristics, not limited to latent period, that could provide greater fitness in nature. Generally, more cycles of selection had greater effects on fitness. In particular cases, selected populations on a partially resistant cultivar had values for latent period, uredinium area, and sporulation no different from those of a susceptible host-pathogen combination. Heritabilities of latent period of populations 881-WT and 882-WT on CI 13227 or populations 881-WT and 882-WT on Sw 72469-6 ranged from 0.65 to 0.76 and 0.17 to 0.24, respectively. Our results suggest the variation to overcome quantitative host resistance exists in extant populations of P. triticina. In addition, because more of the variation in latent period for populations of P. triticina on CI 13227 was genetic than for populations on Sw 72469-6, CI 13227 is likely to be more vulnerable to pathogen adaptation despite its exceptionally long latent period.  相似文献   

Projecting global and regional outlooks for planted forests under the shared socio-economic pathways     

Korhonen  Jaana  Nepal  Prakash  Prestemon  Jeffrey P.  Cubbage  Frederick W. 《New Forests》2021,52(2):197-216

New Forests - There is rising global interest in growing more trees in order to meet growing population, climate change, and wood energy needs. Using recently published data on planted forests by...  相似文献   

Starvation Induced Alterations in Hepatic Lysine Metabolism in Different Families of Rainbow Trout (<Emphasis Type="Italic">Oncorhynchus  mykiss</Emphasis>)     

Angela?D.?Higgins  Jeffrey?T.?Silverstein  Juanita?Engles  Matthew?E.?Wilson  Caird?E.?RexroadIII  Kenneth?P.?BlemingsEmail author 《Fish physiology and biochemistry》2005,31(1):33-44

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Contrasting the ability of data to make inferences regarding dispersal: case study of the Red-cockaded woodpecker (Picoides borealis)     

Douglas J. Bruggeman  Thorsten Wiegand  Jeffrey R. Walters  Fernando González Taboada 《Landscape Ecology》2014,29(4):639-653

Dispersal is a critical biological process that contributes to the persistence of species in complex and dynamic landscapes. However, little is known about the ability of different types of data to reveal how species interact with landscape patterns during dispersal. Further, application of process-based, landscape-scale models able to capture the influence of land use and climate change are limited by this lack of dispersal knowledge. Here we highlight a method for building such models when dispersal parameters are unknown, but information on the mating system and survival are available. We applied a common statistical framework, rooted in information theory, to contrast the ability of abundance, movement, and genetic data to estimate dispersal parameters for endangered Red-cockaded woodpecker (RCW), using an individual-based, spatially-explicit population model. Dispersal was modeled as a multifaceted process in which foray distance, long-distance dispersal, competition for mates, and landscape permeability were treated as uncertain. We found that movement data are three-times more powerful than abundance data collected at the same spatial and temporal scales. However, habitat occupancy data collected over much a shorter time scale but at regional spatial scales were very effective for estimating dispersal. We also found that one-year of abundance data provided a similar reduction in uncertainty as genetic differences among breeding groups estimated using a 24-year pedigree. Substituting population genetic data for movement and abundance data often led to the same parameter values, but not always. Our study highlights important differences in the information content of data commonly collected in the field.  相似文献   

Mapping sources,sinks, and connectivity using a simulation model of northern spotted owls     

Nathan H. Schumaker  Allen Brookes  Jeffrey R. Dunk  Brian Woodbridge  Julie A. Heinrichs  Joshua J. Lawler  Carlos Carroll  David LaPlante 《Landscape Ecology》2014,29(4):579-592

Source-sink dynamics are an emergent property of complex species–landscape interactions. A better understanding of how human activities affect source-sink dynamics has the potential to inform and improve the management of species of conservation concern. Here we use a study of the northern spotted owl (Strix occidentalis caurina) to introduce new methods for quantifying source-sink dynamics that simultaneously describe the population-wide consequences of changes to landscape connectivity. Our spotted owl model is mechanistic, spatially-explicit, individual-based, and incorporates competition with barred owls (Strix varia). Our observations of spotted owl source-sink dynamics could not have been inferred solely from habitat quality, and were sensitive to landscape connectivity and the spatial sampling schemes employed by the model. We conclude that a clear understanding of source-sink dynamics can best be obtained from sampling simultaneously at multiple spatial scales. Our methodology is general, can be readily adapted to other systems, and will work with population models ranging from simple and low-parameter to complex and data-intensive.  相似文献   

Numerical modeling and design of inflatable structures—application to open-ocean-aquaculture cages     

Jeffrey D. Suhey  Nam H. Kim  Christopher Niezrecki   《Aquacultural Engineering》2005,33(4):285-303

Numerical simulation and design of an inflatable open-ocean-aquaculture cage is presented using nonlinear finite element analysis of membrane structures. Numerical instability caused by the tension-only membrane has been removed by adding an artificial shell with small stiffness. The material properties of a fabric material are obtained from tensile tests in both hoop and longitudinal directions, assuming the material is anisotropic. Wrinkling, defined as an onset of compressive stress, is monitored as design criteria. The finite element model is validated using a modified beam theory for the inflatable structure by comparing the maximum deflection and stress. Good agreement is observed between the numerical and theoretical results. A full-scale cage model is created using membrane, shell, and string elements to test the stiffness and integrity of the system. The feasibility study indicates that the inflated structure has sufficient stiffness to be used as the structural support within a fish cage. Based on the parameter study, several designs are suggested.  相似文献   

Role of molecular species catabolism in the temperature-induced restructuring of phosphatidylcholines in liver microsomes of thermally-acclimated rainbow trout (Oncorhynchus mykiss)     

Dr. Jeffrey R. Hazel 《Fish physiology and biochemistry》1996,15(3):195-204

Most previous studies of the temperature-induced restructuring of phospholipid molecular species composition have examined steps in the biosynthesis of phospholipids to explain the accumulation of unsaturated fatty acids in membranes of cold-acclimated poikilotherms. In contrast, the present study explores the role of phospholipases in this restructuring process by determining the rates of degradation of specific molecular species of phosphatidylcholine, using enzymes (microsomes) freshly isolated from the liver of rainbow trout. (Oncorhynchus mykiss) acclimated to either 5° or 20°C. The substrate preparation employed to assay phospholipase activity possessed a range of molecular species, all radiolabeled with 1-¹⁴C-palmitic acid at thesn-1 position, similar to that present in native trout liver microsomes. After defined periods of incubation (120 and 240 min at 5°C; 60 and 120 min at 20°C), phospholipids were extracted from the reaction mixture and the distribution of radioactivity among the molecular species of phosphatidylcholine was determined by HPLC/liquid scintillation counting. In general, molecular species catabolism was not significantly influenced by either assay or acclimation temperature. Only in 20°C-acclimated fish did a reduction in assay temperature (from to 20 to 5°C) result in significantly increased proportions of radioactivity being recovered in one polyunsaturated fatty acid-containing species (16:0/22:6-PC). It is concluded: 1) that phospholipase specificity, assayed under conditions approximating thosein situ, is not significantly influenced by temperature; and 2), that the increased proportions of unsaturated fatty acid-containing molecular species of phosphatidylcholine observed at low temperatures must reflect the specificity of biosynthetic rather than degradative processes.  相似文献   

Effects of modulatory agents on neurally-mediated responses of trout intestinal smooth musclein vitro     

Dr. John F. Burka  Heather A. Briand  Cheryl Ann Wartman  Jeffrey G. Hogan  William P. Ireland 《Fish physiology and biochemistry》1996,15(2):95-104

Mediators and mechanisms responsible for the inhibitory modulation of trout intestinal smooth muscle were examined using a series of putative mediators and substances known to modulate neurotransmission in mammalian systems. Frequency response relationships to transmural stimulation and concentration response relationships to 5-hydroxytryptamine, carbachol, and substance P were established on paired segments of rainbow trout intestinein vitro in the presence and absence of putative modulatory agents. Modulation of neurally-mediated contractions of trout intestine was achieved with dibutyryl cyclic AMP and forskolin, agents that increase intracellular levels of cyclic AMP. The effect appears to be at the level of the smooth muscle, since the adenylate cyclase activator, forskolin, inhibited muscarinic and serotoninergic contractions as well as transmurally stimulated contractions. Substance P-induced contractions were unaffected by forskolin. The endogenous agonists/neurotransmitters which would increase cyclic AMP levels in rainbow trout intestinal smooth muscle are as yet unknown. The effects do not appear to be modulated by vasoactive intestinal peptide (VIP), calcitonin, calcitonin gene-related peptide (CGRP), or agents that activate -adrenoceptors. Prostaglandin E₂ (PGE₂) and ₂-adrenergenic agonists are possible agents which will decrease contractility of the smooth muscle. They were only active in the proximal intestine and on transmurally stimulated contractions. The effects of both PGE₂ and ₂-agonists appear to be prejunctional, decreasing release of contractile neurotransmitters in the enteric nervous system.  相似文献