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Larry M. York - One of the best experts on this subject based on the ideXlab platform.
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A novel multi-perspective imaging platform (M-PIP) for phenotyping soybean Root Crowns in the field increases throughput and separation ability of genotype Root properties
2018Co-Authors: Anand Seethepalli, Hussien Almtarfi, Felix B. Fritschi, Larry M. York, Alina ZareAbstract:Background: Root Crown phenotyping has linked Root properties to shoot mass, nutrient uptake, and yield in the field, which increases the understanding of soil resource acquisition and presents opportunities for breeding. The original methods using manual measurements have been largely supplanted by image-based approaches. However, most image-based systems have been limited to one or two perspectives and rely on segmentation from grayscale images. An efficient high-throughput Root Crown phenotyping system is introduced that takes images from five perspectives simultaneously, constituting the Multi-Perspective Imaging Platform (M-PIP). A segmentation procedure using the Expectation-Maximization Gaussian Mixture Model (EM-GMM) algorithm was developed to distinguish plant Root pixels from background pixels in color images and using hardware acceleration (CPU and GPU). Phenes were extracted using MatLab scripts. Placement of excavated Root Crowns for image acquisition was standardized and is ergonomic. The M-PIP was tested on 24 soybean [Glycine max (L.) Merr.] cultivars released between 1930 and 2005 . Results: Relative to previous reports of imaging throughput, this system provides greater throughput with sustained rates of 1.66 Root Crowns min-1. The EM-GMM segmentation algorithm with hardware acceleration was able to segment images in 10 s, faster than previous methods, and the output images were consistently better connected with less loss of fine detail. Image-based phenes had similar heritabilities as manual measures with the greatest effect sizes observed for Maximum Radius and Fine Radius Frequency. Correlations were also noted, especially among the manual Complexity score and phenes such as number of Roots and Total Root Length. Averaging phenes across perspectives generally increased heritability, and no single perspective consistently performed better than others. Angle-based phenes, Fineness Index, Maximum Width, Holes, Solidity and Width-to-Depth Ratio were the most sensitive to perspective with decreased correlations among perspectives. Conclusion: The substantial heritabilities measured for many phenes suggest that they are potentially useful for breeding. Multiple perspectives together often produced the greatest heritabilities, and no single perspective consistently performed better than others. Thus, as illustrated here for soybean, multiple perspectives may be beneficial for Root Crown phenotyping systems. This system can contribute to breeding efforts that incorporate under-utilized Root phenotypes to increase food security and sustainability.
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Wheat shovelomics II: Revealing relationships between Root Crown traits and crop growth
2018Co-Authors: Shaunagh Slack, Larry M. York, Yadgar Roghazai, Jonathan P. Lynch, Malcolm J. Bennett, J. FoulkesAbstract:Optimization of Root system architecture represents an important goal in wheat breeding. Adopting new field methods for Root phenotyping is key to delivering this goal. A novel 9shovelomics9 method was applied for phenotyping Root Crown traits to characterize the Savannah x Rialto doubled-haploid (DH) population in two field experiments under irrigated and rain-fed conditions. Trait validation was carried out through soil coring on a subset of 14 DH lines and the two parents. We observed that drought reduced grain yield per plant by 21.0%. Under rain-fed conditions, nodal Root angle and Roots shoot-1 were positively associated with Root length density (RLD) at 40-60 cm depth; RLD was also positively correlated with grain yield. Nodal Root angle and Roots shoot-1 were also positively associated with canopy stay green and grain yield under rain-fed conditions. We conclude that shovelomics is a valuable technique for quantifying genetic variation in nodal Root traits in wheat, revealing nodal Root angle and Root number per shoot provide useful selection criteria in breeding programs aimed at improving drought tolerance in wheat.
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Wheat shovelomics I: A field phenotyping approach for characterising the structure and function of Root systems in tillering species
2018Co-Authors: Larry M. York, Shaunagh Slack, Malcolm J. Bennett, M. John FoulkesAbstract:Wheat represents a major crop, yet the current rate of yield improvement is insufficient to meet its projected global food demand. Breeding Root systems more efficient for water and nitrogen capture represents a promising avenue for accelerating yield gains. Root Crown phenotyping, or shovelomics, relies on excavation of the upper portions of Root systems in the field and measuring Root properties such as numbers, angles, densities and lengths. We report a new shovelomics method that images the whole wheat Root Crown, then partitions it into the main shoot and tillers for more intensive phenotyping. Root Crowns were phenotyped using the new method from the Rialto × Savannah population consisting of both parents and 94 doubled-haploid lines. For the whole Root Crown, the main shoot, and tillers, Root phenes including nodal Root number, growth angle, length, and diameter were measured. Substantial variation and heritability were observed for all phenes. Principal component analysis revealed latent constructs that imply pleiotropic genetic control of several related Root phenes. Correlational analysis revealed that nodal Root number and growth angle correlate among the whole Crown, main shoot, and tillers, indicating shared genetic control among those organs. We conclude that this phenomics approach will be useful for breeding ideotype Root systems in tillering species.
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Phenotyping Crop Root Crowns: General Guidance and Specific Protocols for Maize, Wheat, and Soybean.
Methods in molecular biology (Clifton N.J.), 2018Co-Authors: Larry M. YorkAbstract:Root Crown phenotyping allows measuring many parameters that describe the top portion of crop Root systems and can be used for the basis of genome-wide association studies, QTL analysis, and physiology studies. Root Crown phenotyping is a relatively simple process, with the major steps being excavation, transport, soil removal, and measurements. On the other hand, all steps require substantial manual labor and occur outside in challenging environments, and many factors influence the ultimate success of applying this methodology to research questions. Here, general guidance is given for how to optimize Root Crown phenotyping for unique research questions, and specific protocols are given for acquiring images of Root Crowns of three crop species: maize, wheat, and soybean.
Martin Porchas - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Five Fungicides on Development of Root, Crown, and Fruit Rot of Chile Pepper and Recovery of Phytophthora capsici from Soil.
Plant disease, 2000Co-Authors: Michael E. Matheron, Martin PorchasAbstract:The activity of five fungicides, azoxystrobin, dimethomorph, fluazinam, fosetyl-Al, and metalaxyl (subsequently replaced with mefenoxam by the manufacturer), was compared for effects on the development of Root, Crown, and fruit rot of chile pepper and on recovery of Phytophthora capsici from naturally infested soil. When inoculated with zoospores, plants survived longer and shoot and Root fresh weights were greater for plants drenched with metalaxyl at 10 μg/ml than for plants treated with the same rate of azoxystrobin or dimethomorph. At 100 μg/ml, the duration of plant survival was greater for dimethomorph and fluazinam than for azoxystrobin; however, shoot and Root growth did not differ. In soil naturally infested with P. capsici, survival and growth of shoots and Roots for plants treated with dimethomorph at 100 μg/ml were greater than for those treated with the same rate of azoxystrobin or fluazinam. The most effective compounds for inhibition of lesion development on stems and fruit were mefenoxam at 1,200 μg/ml and dimethomorph at 480 μg/ml. Recovery of P. capsici from soil treated with each of the five tested compounds was significantly less than that recorded for soil not receiving a fungicide. The potential and relative value of azoxystrobin, dimethomorph, fosetyl-Al, and fluazinam as chemical management tools for Phytophthora blight on chile pepper, in addition to metalaxyl (replaced with mefenoxam), has been demonstrated.
A. Swirepik - One of the best experts on this subject based on the ideXlab platform.
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The impact of a Root-Crown weevil and pasture competition on the winter annual Echium plantagineum.
Journal of Applied Ecology, 2001Co-Authors: Andy W. Sheppard, M. J. Smyth, A. SwirepikAbstract:Summary 1 Root-feeding insect herbivores may suppress their host populations by altering the competitive balances within the plant community of the host-plant. In this study, repeated field experiments using caged and natural populations of a Root-Crown weevil, Mogulones larvatus, on the annual weed Echium plantagineum (Boraginaceae) were conducted with and without pasture competition in its exotic range. 2 The experiment used a split-plot design, excluding weevils with insecticide and plant competition through weeding. 3 The greatest effect of the weevils was observed when natural densities of weevils occurred on naturally growing E. plantagineum rosettes in the field. Weevils reduced plant survival by 43%, and the size and seed weight of survivors by 58% and 74%, respectively. 4 Pasture competition had a similar impact on E. plantagineum as the weevils for plant size and seed weight, except that there was no impact on rosette survival. There were also no significant interactions between the effects of weevils and competition. Most impact occurred in the second half of the growing season. 5 The number of weevil eggs and larvae and all plant reproductive parameters measured per unit biomass were independent of plant size. 6 Such impact experiments help develop simplified impact assessment methodologies for assessing the success of biological control projects in the field.
William J. Platt - One of the best experts on this subject based on the ideXlab platform.
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Responses of Root-Crown bearing shrubs to differences in fire regimes in Pinus palustris (longleaf pine) savannas: Exploring old-growth questions in second-growth systems
Applied Vegetation Science, 2006Co-Authors: Paul B. Drewa, Jarrod M. Thaxton, William J. PlattAbstract:Question: What are the effects of fire season and intensity on resprouting of different Root-Crown bearing shrub species in second-growth Pinus palustris (longleaf pine) savannas? Location: northern Florida and eastern Louisiana, USA. Methods: In Florida, quadrats were burned biennially either during the dormant season or the growing season. In Louisiana, we applied intensity treatments to quadrats by manipulating ground-cover fuels, just prior to biennial growing season fires. Maximum fire temperatures were measured, and stem densities were censused before and after fires in both regions. Results: After dormant season fires in Florida, stem densities were seven times greater than initial levels for Hypericum spp. In contrast, growing season fires reduced densities of H. brachyphyllum by 65%, but did not change densities of H. microsepalum. Only resprouting of H. microsepalum decreased with increased fire intensity. In Louisiana, fire intensity influenced Ilex vomitoria, but not Quercus spp. Following fires, stem densities of I. vomitoria were five times greater in fuel removal than fuel addition areas. Conclusions: Past use of dormant season fires likely contributed to increased abundances of some species of Root-Crown bearing shrubs observed today in old-growth savannas. Re
Olga Polydorou - One of the best experts on this subject based on the ideXlab platform.
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A temporary filling material during endodontic treatment may cause tooth fractures in two-surface class II cavities in vitro
Clinical Oral Investigations, 2016Co-Authors: Christian Tennert, Gesine Friederike Fischer, Kirstin Vach, Johan Peter Woelber, Elmar Hellwig, Olga PolydorouAbstract:Objectives To investigate the effect of a zinc oxide/zinc sulphate-based cement as a temporary filling material during Root canal treatment on the occurrence of cracks within the filling material or the tooth. Materials and methods Root canals of 122 extracted human molars were prepared using ProTaper instruments. Standardized occlusal-distal cavities were prepared. After placing calcium hydroxide into the Root canals, the teeth were divided randomly into four groups containing 33 specimens each. In the Coltosol group, the cavity was completely filled with Coltosol® F. In the Coltosol-Clearfil group, a 2-mm layer of Coltosol® F was placed into the apical part of the pulp chamber, and in the Clearfil group, a foam pellet was placed into the coronal pulp chamber. The remaining cavities were filled with Clearfil™. In the control group, the cavities were not restored. The teeth were stored at 37 °C for 14 days and examined every 24 h under a stereomicroscope. Results Fractures of the filling and/or the tooth were only observed in the Coltosol group. All Coltosol® F restorations had cracks after 24 h. Tooth fractures were found in 25 (76 %) teeth. Among these teeth, 21 (84 %) had Crown fractures, four (16 %) had Root-Crown fractures. All Root-Crown fractures were vertical. Conclusion Coltosol® F when used alone led to tooth fractures in two-surface class II cavities in teeth undergoing Root canal treatment. Clinical relevance Coltosol® F solely used as restorative material may lead to tooth fractures in two-surface class II cavities.
