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Automated Trichome Counting In Soybean Using Advanced Image‐Processing Techniques, Seyed Vahid Mirnezami, Therin Young, Teshale Assefa, Shelby Prichard, Koushik Nagasubramanian, Kulbir Sandhu, Soumik Sarkar, Sriram Sundararajan, Matthew E. O'Neal, Baskar Ganapathysubramanian, Arti Singh Jul 2020

Automated Trichome Counting In Soybean Using Advanced Image‐Processing Techniques, Seyed Vahid Mirnezami, Therin Young, Teshale Assefa, Shelby Prichard, Koushik Nagasubramanian, Kulbir Sandhu, Soumik Sarkar, Sriram Sundararajan, Matthew E. O'Neal, Baskar Ganapathysubramanian, Arti Singh

Mechanical Engineering Publications

Premise Trichomes are hair‐like appendages extending from the plant epidermis. They serve many important biotic roles, including interference with herbivore movement. Characterizing the number, density, and distribution of trichomes can provide valuable insights on plant response to insect infestation and define the extent of plant defense capability. Automated trichome counting would speed up this research but poses several challenges, primarily because of the variability in coloration and the high occlusion of the trichomes.

Methods and Results We developed a simplified method for image processing for automated and semi‐automated trichome counting. We illustrate this process using 30 leaves from ...


Computer Vision And Machine Learning Enabled Soybean Root Phenotyping Pipeline, Kevin G. Falk, Talukder Z. Jubery, Seyed V. Mirnezami, Kyle A. Parmley, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian, Asheesh K. Singh Jan 2020

Computer Vision And Machine Learning Enabled Soybean Root Phenotyping Pipeline, Kevin G. Falk, Talukder Z. Jubery, Seyed V. Mirnezami, Kyle A. Parmley, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian, Asheesh K. Singh

Mechanical Engineering Publications

Background Root system architecture (RSA) traits are of interest for breeding selection; however, measurement of these traits is difficult, resource intensive, and results in large variability. The advent of computer vision and machine learning (ML) enabled trait extraction and measurement has renewed interest in utilizing RSA traits for genetic enhancement to develop more robust and resilient crop cultivars. We developed a mobile, low-cost, and high-resolution root phenotyping system composed of an imaging platform with computer vision and ML based segmentation approach to establish a seamless end-to-end pipeline - from obtaining large quantities of root samples through image based trait processing and ...


Targeted Suppression Of Soybean Bag6‐Induced Cell Death In Yeast By Soybean Cyst Nematode Effectors, Jianying Wang, Greg Yeckel, Pramod K. Kandoth, Lakmini Wasala, Richard S. Hussey, Eric L. Davis, Thomas J. Baum, Melissa G. Mitchum Jan 2020

Targeted Suppression Of Soybean Bag6‐Induced Cell Death In Yeast By Soybean Cyst Nematode Effectors, Jianying Wang, Greg Yeckel, Pramod K. Kandoth, Lakmini Wasala, Richard S. Hussey, Eric L. Davis, Thomas J. Baum, Melissa G. Mitchum

Plant Pathology and Microbiology Publications

While numerous effectors that suppress plant immunity have been identified from bacteria, fungi, and oomycete pathogens, relatively little is known for nematode effectors. Several dozen effectors have been reported from the soybean cyst nematode (SCN). Previous studies suggest that a hypersensitive response‐like programmed cell death is triggered at nematode feeding sites in soybean during an incompatible interaction. However, virulent SCN populations overcome this incompatibility using unknown mechanisms. A soybean BAG6 (Bcl‐2 associated anthanogene 6) gene previously reported by us to be highly up‐regulated in degenerating feeding sites induced by SCN in a resistant soybean line was attenuated ...


Screening Soybean Cyst Nematode Effectors For Their Ability To Suppress Plant Immunity, Gennady Pogorelko, Jianying Wang, Parijat S. Juvale, Melissa G. Mitchum, Thomas J. Baum Jan 2020

Screening Soybean Cyst Nematode Effectors For Their Ability To Suppress Plant Immunity, Gennady Pogorelko, Jianying Wang, Parijat S. Juvale, Melissa G. Mitchum, Thomas J. Baum

Plant Pathology and Microbiology Publications

The soybean cyst nematode (SCN), Heterodera glycines , is one of the most destructive pathogens of soybeans. SCN is an obligate and sedentary parasite that transforms host plant root cells into an elaborate permanent feeding site, a syncytium. Formation and maintenance of a viable syncytium is an absolute requirement for nematode growth and reproduction. In turn, sensing pathogen attack, plants activate defence responses and may trigger programmed cell death at the sites of infection. For successful parasitism, H. glycines must suppress these host defence responses to establish and maintain viable syncytia. Similar to other pathogens, H. glycines engages in these molecular ...


Deconstructing The Genetic Architecture Of Iron Deficiency Chlorosis In Soybean Using Genome-Wide Approaches, Teshale Assefa, Jiaoping Zhang, R. V. Chowda-Reddy, Adrienne N. Moran Lauter, Arti Singh, Jamie A. O'Rourke, Michelle A. Graham, Asheesh K. Singh Jan 2020

Deconstructing The Genetic Architecture Of Iron Deficiency Chlorosis In Soybean Using Genome-Wide Approaches, Teshale Assefa, Jiaoping Zhang, R. V. Chowda-Reddy, Adrienne N. Moran Lauter, Arti Singh, Jamie A. O'Rourke, Michelle A. Graham, Asheesh K. Singh

Agronomy Publications

Background: Iron (Fe) is an essential micronutrient for plant growth and development. Iron deficiency chlorosis (IDC), caused by calcareous soils or high soil pH, can limit iron availability, negatively affecting soybean (Glycine max) yield. This study leverages genome-wide association study (GWAS) and a genome-wide epistatic study (GWES) with previous gene expression studies to identify regions of the soybean genome important in iron deficiency tolerance.

Results: A GWAS and a GWES were performed using 460 diverse soybean PI lines from 27 countries, in field and hydroponic iron stress conditions, using more than 36,000 single nucleotide polymorphism (SNP) markers. Combining this ...


Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian Aug 2019

Plant Disease Identification Using Explainable 3d Deep Learning On Hyperspectral Images, Koushik Nagasubramanian, Sarah Jones, Asheesh K. Singh, Soumik Sarkar, Arti Singh, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Background

Hyperspectral imaging is emerging as a promising approach for plant disease identification. The large and possibly redundant information contained in hyperspectral data cubes makes deep learning based identification of plant diseases a natural fit. Here, we deploy a novel 3D deep convolutional neural network (DCNN) that directly assimilates the hyperspectral data. Furthermore, we interrogate the learnt model to produce physiologically meaningful explanations. We focus on an economically important disease, charcoal rot, which is a soil borne fungal disease that affects the yield of soybean crops worldwide.

Results

Based on hyperspectral imaging of inoculated and mock-inoculated stem images, our 3D ...


Homeostasis In The Soybean Mirna396–Grf Network Is Essential For Productive Soybean Cyst Nematode Infections, Jason B. Noon, Tarek Hewezi, Thomas J. Baum Jan 2019

Homeostasis In The Soybean Mirna396–Grf Network Is Essential For Productive Soybean Cyst Nematode Infections, Jason B. Noon, Tarek Hewezi, Thomas J. Baum

Plant Pathology and Microbiology Publications

Heterodera glycines, the soybean cyst nematode, penetrates soybean roots and migrates to the vascular cylinder where it forms a feeding site called the syncytium. MiRNA396 (miR396) targets growth-regulating factor (GRF) genes, and the miR396–GRF1/3 module is a master regulator of syncytium development in model cyst nematode H. schachtii infection of Arabidopsis. Here, we investigated whether this regulatory system operates similarly in soybean roots and is likewise important for H. glycines infection. We found that a network involving nine MIR396 and 23 GRF genes is important for normal development of soybean roots and that GRF function is specified in ...


Regenerating Agricultural Landscapes With Perennial Groundcover For Intensive Crop Production, Kenneth J. Moore, Robert P. Anex, Amani E. Elobeid, Shuizhang Fei, Cornelia B. Flora, A. Susana Goggi, Keri L. Jacobs, Prashant Jha, Amy L. Kaleita, Douglas L. Karlen, David A. Laird, Andrew W. Lenssen, Thomas Lubberstedt, Marshall D. Mcdaniel, D. Raj Raman, Sharon L. Weyers Jan 2019

Regenerating Agricultural Landscapes With Perennial Groundcover For Intensive Crop Production, Kenneth J. Moore, Robert P. Anex, Amani E. Elobeid, Shuizhang Fei, Cornelia B. Flora, A. Susana Goggi, Keri L. Jacobs, Prashant Jha, Amy L. Kaleita, Douglas L. Karlen, David A. Laird, Andrew W. Lenssen, Thomas Lubberstedt, Marshall D. Mcdaniel, D. Raj Raman, Sharon L. Weyers

Agronomy Publications

The Midwestern U.S. landscape is one of the most highly altered and intensively managed ecosystems in the country. The predominant crops grown are maize (Zea mays L.) and soybean [Glycine max (L.) Merr]. They are typically grown as monocrops in a simple yearly rotation or with multiple years of maize (2 to 3) followed by a single year of soybean. This system is highly productive because the crops and management systems have been well adapted to the regional growing conditions through substantial public and private investment. Furthermore, markets and supporting infrastructure are highly developed for both crops. As maize ...


Genetic Control And Geo-Climate Adaptation Of Pod Dehiscence Provide Novel Insights Into The Soybean Domestication And Expansion, Jiaoping Zhang, Asheesh K. Singh Aug 2018

Genetic Control And Geo-Climate Adaptation Of Pod Dehiscence Provide Novel Insights Into The Soybean Domestication And Expansion, Jiaoping Zhang, Asheesh K. Singh

Agronomy Publications

Loss of pod dehiscence is a key step during soybean [Glycine max (L.) Merr.] domestication. Genome-wide association analysis for soybean shattering identified loci harboring Pdh1, NST1A and SHAT1-5. Pairwise epistatic interactions were observed, and the dehiscent Pdh1 overcomes the resistance conferred by NST1A or SHAT1-5 locus, indicating that Pdh1 predominates pod dehiscence expression. Further candidate gene association analysis identified a nonsense mutation in NST1A associated with pod dehiscence. Allele composition and population differential analyses unraveled that Pdh1 and NST1A, but not SHAT1-5, underwent domestication and modern breeding selections. Geographic analysis showed that in Northeast China (NEC), indehiscence at both Pdh1 ...


Sifting And Winnowing: Analysis Of Farmer Field Data For Soybean In The Us North-Central Region, Spyridon Mourtzinis, Juan I. Rattalino Edreira, Patricio Grassini, Adam C. Roth, Shaun N. Casteel, Ignacio A. Ciampitti, Hans J. Kandel, Peter M. Kyveryga, Mark A. Licht, Laura E. Lindsey, Daren S. Mueller, Emerson D. Nafziger, Seth L. Naeve, Jordan Stanley, Michael J. Staton, Shawn P. Conley May 2018

Sifting And Winnowing: Analysis Of Farmer Field Data For Soybean In The Us North-Central Region, Spyridon Mourtzinis, Juan I. Rattalino Edreira, Patricio Grassini, Adam C. Roth, Shaun N. Casteel, Ignacio A. Ciampitti, Hans J. Kandel, Peter M. Kyveryga, Mark A. Licht, Laura E. Lindsey, Daren S. Mueller, Emerson D. Nafziger, Seth L. Naeve, Jordan Stanley, Michael J. Staton, Shawn P. Conley

Agronomy Publications

Field trials are commonly used to estimate the effects of different factors on crop yields. In the present study, we followed an alternative approach to identify factors that explain field-to-field yield variation, which consisted of farmer survey data, a spatial framework, and multiple statistical procedures. This approach was used to identify management factors with strongest association with on-farm soybean yield variation in the US North Central (NC) region. Field survey data, including yield and management information, were collected over two crop growing seasons (2014 and 2015) from rainfed and irrigated soybean fields (total of 3568 field-year observations). Fields were grouped ...


A Solution For Sampling Position Errors In Maize And Soybean Root Mass And Length Estimates, Raziel A. Ordonez, Michael J. Castellano, Jerry L. Hatfield, Mark A. Licht, Emily E. Wright, Sotirios V. Archontoulis May 2018

A Solution For Sampling Position Errors In Maize And Soybean Root Mass And Length Estimates, Raziel A. Ordonez, Michael J. Castellano, Jerry L. Hatfield, Mark A. Licht, Emily E. Wright, Sotirios V. Archontoulis

Agronomy Publications

Root mass and length attributes are difficult to obtain in the field and currently there is uniformity among literature studies in estimating the effect of sampling position error. With the objectives of 1) quantifying the sampling position error in calculating weighted average root values per unit area and 2) developing an algorithm to minimize root position sampling error so that existing data in the literature can be used in future studies, we collected and analyzed root mass and length data across four sampling positions (0, 12, 24 and 36 cm distance from the plant row; row-to-row spacing 76 cm) from ...


Management Of Insecticide-Resistant Soybean Aphids In The Upper Midwest Of The United States, Robert L. Koch, Erin W. Hodgson, Janet J. Knodel, Adam J. Varenhorst, Bruce D. Potter Jan 2018

Management Of Insecticide-Resistant Soybean Aphids In The Upper Midwest Of The United States, Robert L. Koch, Erin W. Hodgson, Janet J. Knodel, Adam J. Varenhorst, Bruce D. Potter

Entomology Publications

Since the first observation of soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in North America in 2000, it has become the most economically damaging insect of soybean in the Upper Midwest of the United States. For the last 17 yr, soybean aphid management has relied almost entirely on the use of foliar-applied broad-spectrum insecticides. However, in 2015 in Minnesota, failures of foliar-applied pyrethroid insecticides were reported and pyrethroid resistance was confirmed with laboratory bioassays using lambda-cyhalothrin and bifenthrin. In 2016 and 2017, further reports of failures of pyrethroid insecticides and/or laboratory confirmation of resistance occurred in Iowa, North Dakota ...


Assessing Causes Of Yield Gaps In Agricultural Areas With Diversity In Climate And Soils, Juan I. Rattalino Edreira, Spyridon Mourtzinis, Shawn P. Conley, Adam C. Roth, Ignacio A. Ciampitti, Mark A. Licht, Hans Kandel, Peter M. Kyveryga, Laura E. Lindsey, Daren S. Mueller, Seth L. Naeve, Emerson Nafziger, James E. Specht, Jordan Stanley, Michael J. Staton, Patricio Grassini Dec 2017

Assessing Causes Of Yield Gaps In Agricultural Areas With Diversity In Climate And Soils, Juan I. Rattalino Edreira, Spyridon Mourtzinis, Shawn P. Conley, Adam C. Roth, Ignacio A. Ciampitti, Mark A. Licht, Hans Kandel, Peter M. Kyveryga, Laura E. Lindsey, Daren S. Mueller, Seth L. Naeve, Emerson Nafziger, James E. Specht, Jordan Stanley, Michael J. Staton, Patricio Grassini

Agronomy Publications

Identification of causes of gaps between yield potential and producer yields has been restricted to small geographic areas. In the present study, we developed a novel approach for identifying causes of yield gaps over large agricultural areas with diversity in climate and soils. This approach was applied to quantify and explain yield gaps in rainfed and irrigated soybean in the North-Central USA (NC USA) region, which accounts for about one third of soybean global production. Survey data on yield and management were collected from 3568 producer fields over two crop seasons and grouped into 10 technology extrapolation domains (TEDs) according ...


Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges, Mark A. Chamberlin, Marc C. Albertsen, Harry T. Horner Oct 2017

Microscopic Characterization Of A Transposon-Induced Male-Sterile, Female-Sterile Mutant In Glycine Max L., Katherine A. Thilges, Mark A. Chamberlin, Marc C. Albertsen, Harry T. Horner

Genetics, Development and Cell Biology Publications

Premise of research. A male-sterile, female-sterile mutant was discovered in a w4-m mutable line of Glycine max L. The mechanism of its sterility was not well understood. Therefore, different cytological and microscopic techniques were undertaken to better understand the process of mutant phenotype development. Molecular research indicated that mer3 was responsible for the sterility.

Methodology. Macro images were collected of whole plants, flowers, anthers, pods, and ovules. Chromosome spreads from anthers at various meiotic stages were examined. Confocal scanning laser microscopy using optical sectioning was utilized on whole anthers and ovules at various developmental stages. Whole mature anthers and ...


Genetic Architecture Of Charcoal Rot (Macrophomina Phaseolina) Resistance In Soybean Revealed Using A Diverse Panel, Sara M. Coser, R. V. Chowda Reddy, Jiaoping Zhang, Daren S. Mueller, Alemu Mengistu, Kiersten A. Wise, Tom W. Allen, Arti Singh, Asheesh K. Singh Sep 2017

Genetic Architecture Of Charcoal Rot (Macrophomina Phaseolina) Resistance In Soybean Revealed Using A Diverse Panel, Sara M. Coser, R. V. Chowda Reddy, Jiaoping Zhang, Daren S. Mueller, Alemu Mengistu, Kiersten A. Wise, Tom W. Allen, Arti Singh, Asheesh K. Singh

Agronomy Publications

Charcoal rot (CR) disease caused by Macrophomina phaseolina is responsible for significant yield losses in soybean production. Among the methods available for controlling this disease, breeding for resistance is the most promising. Progress in breeding efforts has been slow due to the insufficient information available on the genetic mechanisms related to resistance. Genome-wide association studies (GWAS) enable unraveling the genetic architecture of resistance and identification of causal genes. The aims of this study were to identify new sources of resistance to CR in a collection of 459 diverse plant introductions from the USDA Soybean Germplasm Core Collection using field and ...


The Effect Of Five Biomass Cropping Systems On Soil-Saturated Hydraulic Conductivity Across A Topographic Gradient, Lisa A. Schulte-Moore, Matthew J. Helmers, Randall K. Kolka Sep 2017

The Effect Of Five Biomass Cropping Systems On Soil-Saturated Hydraulic Conductivity Across A Topographic Gradient, Lisa A. Schulte-Moore, Matthew J. Helmers, Randall K. Kolka

Agricultural and Biosystems Engineering Publications

Understanding the environmental impact of bioenergy crops is needed to inform bioenergy policy development. We determined the effects of five biomass cropping systems—continuous maize (Zea mays), soybean (Glycine max)-triticale (Triticosecale ×)/soybean-maize, maize-switchgrass (Panicum virgatum), triticale/sorghum (Sorghum bicolor), and triticale-aspen (Populus alba × P. grandidentata)—on soil-saturated hydraulic conductivity (K S ) across a toposequence in central Iowa, USA. We compared data from the time of cropping system establishment in 2009 to 4 years post-establishment. Both our 2009 and 2013 data confirmed that cropping system impacts on K S vary by landscape position. We found that differences in cropping system ...


Isolation And Characterization Of The Aconitate Hydratase 4 (Aco4) Gene From Soybean, Z Coleman, J. Boelter, K. Espinosa, A. S. Goggi, R. G. Palmer, D. Sandhu Feb 2017

Isolation And Characterization Of The Aconitate Hydratase 4 (Aco4) Gene From Soybean, Z Coleman, J. Boelter, K. Espinosa, A. S. Goggi, R. G. Palmer, D. Sandhu

Agronomy Publications

Aconitase catalyzes the reversible isomerization of two tricarboxylic acids, citrate and isocitrate, during the Krebs cycle. Five aconitase genes, namely, Aco1, Aco2, Aco3, Aco4, and Aco5, have been identified in soybean. Previously, Aco4 was mapped on chromosome 11. The purpose of this investigation was to isolate and sequence the candidate gene for Aco4. We mapped the Aco4 gene to a 148 kb region on chromosome 11 that contained 19 predicted genes. One of these, Glyma.11G080600, codes for aconitate hydratase. Sequencing of two isozyme variants (A-line and B-line) for Glyma.11G080600 revealed three synonymous and two non-synonymous substitutions. Perhaps, the ...


Advancing Our Understanding Of Charcoal Rot In Soybeans, Martha P. Romero Luna, Daren Mueller, Alemu Mengistu, Asheesh K. Singh, Glen L. Hartman, Kiersten A. Wise Jan 2017

Advancing Our Understanding Of Charcoal Rot In Soybeans, Martha P. Romero Luna, Daren Mueller, Alemu Mengistu, Asheesh K. Singh, Glen L. Hartman, Kiersten A. Wise

Agronomy Publications

Charcoal rot [Macrophomina phaseolina (Tassi) Goid] of soybean [Glycine max (L.) Merr.] is an important but commonly misidentified disease, and very few summary articles exist on this pathosystem. Research conducted over the past 10 yr has improved our understanding of the environment conducive to disease development, host resistance, and improved disease diagnosis and management. This article summarizes the currently available research with an emphasis on disease management.


Soybean Proteins Gmtic110 And Gmpsbp Are Crucial For Chloroplast Development And Function, Devinder Sandhu, Taylor Atkinson, Andrea Noll, Callie Johnson, Katherine Espinosa, Jessica Boelter, Stephanie Abel, Balpreet K. Dhatt, Terese Barta, Eric Singsaas, Sol Sepsenwol, A. Susana Goggi, Reid G. Palmer Nov 2016

Soybean Proteins Gmtic110 And Gmpsbp Are Crucial For Chloroplast Development And Function, Devinder Sandhu, Taylor Atkinson, Andrea Noll, Callie Johnson, Katherine Espinosa, Jessica Boelter, Stephanie Abel, Balpreet K. Dhatt, Terese Barta, Eric Singsaas, Sol Sepsenwol, A. Susana Goggi, Reid G. Palmer

Agronomy Publications

We have identified a viable-yellow and a lethal-yellow chlorophyll-deficient mutant in soybean. Segregation patterns suggested single-gene recessive inheritance for each mutant. The viable- and lethal-yellow plants showed significant reduction of chlorophyll aand b. Photochemical energy conversion efficiency and photochemical reflectance index were reduced in the viable-yellow plants relative to the wildtype, whereas the lethal-yellow plants showed no electron transport activity. The viable-yellow plants displayed reduced thylakoid stacking, while the lethal-yellow plants exhibited failure of proplastid differentiation into normal chloroplasts with grana. Genetic analysis revealed recessive epistatic interaction between the viable- and the lethal-yellow genes. The viable-yellow gene was mapped ...


Virus-Induced Gene Silencing And Transient Gene Expression In Soybean (Glycine Max) Using Bean Pod Mottle Virus Infectious Clones, Steven A. Whitham, Lori M. Lincoln, R. V. Chowda-Reddy, Jaime D. Dittman, Jamie A. O'Rourke, Michelle A. Graham Jun 2016

Virus-Induced Gene Silencing And Transient Gene Expression In Soybean (Glycine Max) Using Bean Pod Mottle Virus Infectious Clones, Steven A. Whitham, Lori M. Lincoln, R. V. Chowda-Reddy, Jaime D. Dittman, Jamie A. O'Rourke, Michelle A. Graham

Plant Pathology and Microbiology Publications

Virus-induced gene silencing (VIGS) is a powerful and rapid approach for determining the functions of plant genes. The basis of VIGS is that a viral genome is engineered so that it can carry fragments of plant genes, typically in the 200 to 300 base pair size range. The recombinant viruses are used to infect experimental plants, and wherever the virus invades, the target gene or genes will be silenced. VIGS is thus transient, and in the span of a few weeks, it is possible to design VIGS constructs and then generate loss-of-function phenotypes through RNA silencing of the target genes ...


Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis Jan 2016

Modeling Long-Term Corn Yield Response To Nitrogen Rate And Crop Rotation, Laila A. Puntel, John E. Sawyer, Daniel Barker, Ranae N. Dietzel, Hanna Poffenbarger, Michael J. Castellano, Kenneth J. Moore, Peter Thorburn, Sotirios Archontoulis

Agronomy Publications

Improved prediction of optimal N fertilizer rates for corn (Zea mays L.) can reduce N losses and increase profits. We tested the ability of the Agricultural Production Systems sIMulator (APSIM) to simulate corn and soybean (Glycine max L.) yields, the economic optimum N rate (EONR) using a 16-year field-experiment dataset from central Iowa, USA that included two crop sequences (continuous corn and soybean-corn) and five N fertilizer rates (0, 67, 134, 201, and 268 kg N ha-1) applied to corn. Our objectives were to: (a) quantify model prediction accuracy before and after calibration, and report calibration steps; (b) compare ...


Candidate Perennial Bioenergy Grasses Have A Higher Albedo Than Annual Row Crops, Jesse N. Miller, Andy Vanloocke, Nuria Gomez-Casanovas, Carl J. Bernacchi Jan 2016

Candidate Perennial Bioenergy Grasses Have A Higher Albedo Than Annual Row Crops, Jesse N. Miller, Andy Vanloocke, Nuria Gomez-Casanovas, Carl J. Bernacchi

Agronomy Publications

The production of perennial cellulosic feedstocks for bioenergy presents the potential to diversify regional economies and the national energy supply, while also serving as climate ‘regulators’ due to a number of biogeochemical and biogeophysical differences relative to row crops. Numerous observational and model-based approaches have investigated biogeochemical trade-offs, such as increased carbon sequestration and increased water use, associated with growing cellulosic feedstocks. A less understood aspect is the biogeophysical changes associated with the difference in albedo (a), which could alter the local energy balance and cause local to regional cooling several times larger than that associated with offsetting carbon. Here ...


Reduced Fitness Of Virulent Aphis Glycines (Hemiptera: Aphididae) Biotypes May Influence The Longevity Of Resistance Genes In Soybean, Adam J. Varenhorst, Michael T. Mccarville, Matthew E. O'Neal Sep 2015

Reduced Fitness Of Virulent Aphis Glycines (Hemiptera: Aphididae) Biotypes May Influence The Longevity Of Resistance Genes In Soybean, Adam J. Varenhorst, Michael T. Mccarville, Matthew E. O'Neal

Entomology Publications

Sustainable use of insect resistance in crops require insect resistance management plans that may include a refuge to limit the spread of virulence to this resistance. However, without a loss of fitness associated with virulence, a refuge may not prevent virulence from becoming fixed within a population of parthenogenetically reproducing insects like aphids. Aphid-resistance in soybeans (i.e., Rag genes) prevent outbreaks of soybean aphid (Aphis glycines), yet four biotypes defined by their capacity to survive on aphid-resistant soybeans (e.g., biotype-2 survives on Rag1 soybean) are found in North America. Although fitness costs are reported for biotype-3 on aphid ...


Survey Of Soybean Insect Pollinators: Community Identification And Sampling Method Analysis, K. A. Gill, M. E. O'Neal Jun 2015

Survey Of Soybean Insect Pollinators: Community Identification And Sampling Method Analysis, K. A. Gill, M. E. O'Neal

Entomology Publications

Soybean, Glycine max (L.) Merrill, flowers can be a source of nectar and pollen for honey bees, Apis mellifera L. (Hymenoptera: Apidae), wild social and solitary bees (Hymenoptera: Apoidea), and flower-visiting flies (Diptera). Our objectives were to describe the pollinator community in soybean fields, determine which sampling method is most appropriate for characterizing their abundance and diversity, and gain insight into which pollinator taxa may contact soybean pollen. We compared modified pan traps (i.e., bee bowls), yellow sticky traps, and sweep nets for trapping pollinators in Iowa soybean fields when soybeans were blooming (i.e., reproductive stages R1–R6 ...


Evaluation Of Spontaneous Generation Of Allelic Variation In Soybean In Response To Sexual Hybridization And Stress, Katherine Espinosa, Jessica Boelter, Susan Lolle, Marianne Hopkins, Susana Goggi, Reid G. Palmer, Devinder Sandhu Mar 2015

Evaluation Of Spontaneous Generation Of Allelic Variation In Soybean In Response To Sexual Hybridization And Stress, Katherine Espinosa, Jessica Boelter, Susan Lolle, Marianne Hopkins, Susana Goggi, Reid G. Palmer, Devinder Sandhu

Agronomy Publications

Intra-cultivar variation reported in pure lines of soybean has been hypothesized to result from genetic mechanisms contributing to de novo genetic variation. In this study we have detected allele switching by following segregation pattern of Aconitase-4 isozyme in sexual crosses and pure lines. In sexual crosses, one F2 plant showed switch at the Aconitase- 4 (Aco4) locus from the expected heterozygous genotype Aco4-ac to Aco4-ab. In the pure lines grown in a honeycomb planting design and treated with an accelerated aging test, multiple cases of allele switching were detected at the Aco4 locus. Both single and double switches were detected ...


Aboveground Feeding By Soybean Aphid, Aphis Glycines, Affects Soybean Cyst Nematode, Heterodera Glycines, Reproduction Belowground, Michael T. Mccarville, David H. Soh, Gregory L. Tylka, Matthew E. O'Neal Jan 2014

Aboveground Feeding By Soybean Aphid, Aphis Glycines, Affects Soybean Cyst Nematode, Heterodera Glycines, Reproduction Belowground, Michael T. Mccarville, David H. Soh, Gregory L. Tylka, Matthew E. O'Neal

Entomology Publications

Heterodera glycines is a cyst nematode that causes significant lost soybean yield in the U.S. Recent studies observed the aphid Aphis glycines and H. glycines interacting via their shared host, soybean, Glycine max. A greenhouse experiment was conducted to discern the effect ofA. glycines feeding on H. glycines reproduction. An H. glycines-susceptible cultivar, Kenwood 94, and a resistant cultivar, Dekalb 27–52, were grown in H. glycines-infested soil for 30 and 60 d. Ten days after planting, plants were infested with either zero, five, or ten aphids. At 30 and 60 d, the number of H ...


Identification Of Candidate Genes Involved In Early Iron Deficiency Chlorosis Signaling In Soybean (Glycine Max) Roots And Leaves, Adrienne N. Moran-Lauter, Gregory Allan Peiffer, Tengfei Yin, Steven A. Whitham, Dianne Cook, Randy Shoemaker, Michelle Graham Jan 2014

Identification Of Candidate Genes Involved In Early Iron Deficiency Chlorosis Signaling In Soybean (Glycine Max) Roots And Leaves, Adrienne N. Moran-Lauter, Gregory Allan Peiffer, Tengfei Yin, Steven A. Whitham, Dianne Cook, Randy Shoemaker, Michelle Graham

Plant Pathology and Microbiology Publications

Background

Iron is an essential micronutrient for all living things, required in plants for photosynthesis, respiration and metabolism. A lack of bioavailable iron in soil leads to iron deficiency chlorosis (IDC), causing a reduction in photosynthesis and interveinal yellowing of leaves. Soybeans (Glycine max (L.) Merr.) grown in high pH soils often suffer from IDC, resulting in substantial yield losses. Iron efficient soybean cultivars maintain photosynthesis and have higher yields under IDC-promoting conditions than inefficient cultivars.

Results

To capture signaling between roots and leaves and identify genes acting early in the iron efficient cultivar Clark, we conducted a RNA-Seq study ...


Candidate Gene Identification For A Lethal Chlorophyll-Deficient Mutant In Soybean, Sam Reed, Taylor Atkinson, Carly Gorecki, Katherine Espinosa, Sarah Przybylski, Alcira Susana Goggi, Reid G. Palmer, Devinder Sandhu Jan 2014

Candidate Gene Identification For A Lethal Chlorophyll-Deficient Mutant In Soybean, Sam Reed, Taylor Atkinson, Carly Gorecki, Katherine Espinosa, Sarah Przybylski, Alcira Susana Goggi, Reid G. Palmer, Devinder Sandhu

Agronomy Publications

Chlorophyll-deficient mutants have been studied persistently to understand genetic mechanisms controlling metabolic pathways. A spontaneous chlorophyll-deficient lethal mutant was observed in self-pollinated progeny of a soybean cultivar “BSR 101”. Observed segregation patterns indicated single-gene recessive inheritance for this lethal-yellow mutant. The objectives of this investigation were to develop a genetic linkage map of the region containing the lethal-yellow (YL_PR350) gene and identify putative candidate genes for this locus. The YL_PR350 gene was mapped to chromosome 15 and is flanked by BARCSOYSSR_15_1591 and BARCSOYSSR_15_1597. This region physically spans ~153 kb and there are 14 predicted genes that lie in this region ...


Effects Of Rag1 On The Preference And Performance Of Soybean Defoliators, Robert F. Bruner, Erin W. Hodgson, Aaron J. Gassmann Dec 2013

Effects Of Rag1 On The Preference And Performance Of Soybean Defoliators, Robert F. Bruner, Erin W. Hodgson, Aaron J. Gassmann

Entomology Publications

The Rag1 gene confers antibiotic resistance to soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and in 2010, varieties expressing Rag1 were released for commercial use in the United States. We do not know how Rag1 varieties will influence the broader community of defoliating insects that inhabit soybean fields. In 2010 and 2011, the preference and performance of pest insects that defoliate soybeans [Glycines max (L.) Merr] were tested using Rag1 and aphidsusceptible varieties. Three coleopterans and four lepidopterans were used: northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae); southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae); bean leaf beetle, Ceratoma trifurcata ...


A Virus-Induced Gene Silencing Method To Study Soybean Cyst Nematode Parasitism In Glycine Max, Pramod K. Kandoth, Robert Heinz, Gregory Yeckel, Nathan W. Gross, Parijat S. Juvale, John H. Hill, Steven A. Whitham, Thomas J. Baum, Melissa G. Mitchum Jan 2013

A Virus-Induced Gene Silencing Method To Study Soybean Cyst Nematode Parasitism In Glycine Max, Pramod K. Kandoth, Robert Heinz, Gregory Yeckel, Nathan W. Gross, Parijat S. Juvale, John H. Hill, Steven A. Whitham, Thomas J. Baum, Melissa G. Mitchum

Plant Pathology and Microbiology Publications

Background

Bean pod mottle virus (BPMV) based virus-induced gene silencing (VIGS) vectors have been developed and used in soybean for the functional analysis of genes involved in disease resistance to foliar pathogens. However, BPMV-VIGS protocols for studying genes involved in disease resistance or symbiotic associations with root microbes have not been developed.

Findings

Here we describe a BPMV-VIGS protocol suitable for reverse genetic studies in soybean roots. We use this method for analyzing soybean genes involved in resistance to soybean cyst nematode (SCN). A detailed SCN screening pipeline is described.

Conclusions

The VIGS method described here provides a new tool ...