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Agricultural Science

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A Public–Industry Partnership For Enhancing Corn Nitrogen Research And Datasets: Project Description, Methodology, And Outcomes, Newell R. Kitchen, John F. Shanahan, Curtis J. Ransom, Christopher J. Bandura, Gregory M. Bean, James J. Camberato, Paul R. Carter, Jason D. Clark, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A.M. Laboski, Emerson D. Nafziger, Zhisheng Qing, John E. Sawyer, Matt Shafer Oct 2019

A Public–Industry Partnership For Enhancing Corn Nitrogen Research And Datasets: Project Description, Methodology, And Outcomes, Newell R. Kitchen, John F. Shanahan, Curtis J. Ransom, Christopher J. Bandura, Gregory M. Bean, James J. Camberato, Paul R. Carter, Jason D. Clark, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A.M. Laboski, Emerson D. Nafziger, Zhisheng Qing, John E. Sawyer, Matt Shafer

Jason Clark

Due to economic and environmental consequences of N lost from fertilizer applications in corn (Zea mays L.), considerable public and industry attention has been devoted to the development of N decision tools. Needed are research and databases and associated metadata, at numerous locations and years to represent a wide geographic range of soil and weather scenarios, for evaluating tool performance. The goals of this research were to conduct standardized corn N rate response field studies to evaluate the performance of multiple public-domain N decision tools across diverse soils and environmental conditions, develop and publish new agronomic science for improved crop ...


Sheet‐Extruded Films From Blends Of Hydroxypropylated And Native Corn Starches, And Their Characterization, Hee-Young Kim, Buddhi P. Lamsal, Jay-Lin Jane, David A. Grewell Aug 2019

Sheet‐Extruded Films From Blends Of Hydroxypropylated And Native Corn Starches, And Their Characterization, Hee-Young Kim, Buddhi P. Lamsal, Jay-Lin Jane, David A. Grewell

Jay-Lin Jane

Sheet‐extruded films from the blends of hydroxypropylated normal corn starch (HP) and native normal corn starch (NS) at weight ratios of 100:0, 90:10, 70:30, 50:50, 30:70, and 0:100 were prepared and characterized. Glycerol and water were added as plasticizers at 11 and 27% starch weight, respectively. The highest tensile strength (TS) and longest elongation to break (EB) for dry films were observed at 70:30 HP: NS ratio, which was 25.76 MPa, and 3.97%, respectively. However, TS and EB of this 70:30 blend extruded starch film exhibited low resistance upon ...


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 Aug 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

Andrew W. Lenssen

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 ...


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 Aug 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

Douglas L Karlen

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 ...


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 Aug 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

D. Raj Raman

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 ...


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 Aug 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

Amy L. Kaleita

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 ...


Qqs Orphan Gene And Its Interactor Nf‐Yc4 Reduce Susceptibility To Pathogens And Pests, Mingsheng Qi, Wenguang Zheng, Xuefeng Zhao, Jessica D. Hohenstein, Yuba Kandel, Seth O’Conner, Yifan Wang, Chuanlong Du, Dan Nettleton, Gustavo C. Macintosh, Gregory L. Tylka, Eve Syrkin Wurtele, Steven A. Whitham, Ling Li Aug 2019

Qqs Orphan Gene And Its Interactor Nf‐Yc4 Reduce Susceptibility To Pathogens And Pests, Mingsheng Qi, Wenguang Zheng, Xuefeng Zhao, Jessica D. Hohenstein, Yuba Kandel, Seth O’Conner, Yifan Wang, Chuanlong Du, Dan Nettleton, Gustavo C. Macintosh, Gregory L. Tylka, Eve Syrkin Wurtele, Steven A. Whitham, Ling Li

Ling Li

Enhancing the nutritional quality and disease resistance of crops without sacrificing productivity is a key issue for developing varieties that are valuable to farmers and for simultaneously improving food security and sustainability. Expression of the Arabidopsis thaliana species‐specific AtQQS (Qua‐Quine Starch) orphan gene or its interactor, NF‐YC4 (Nuclear Factor Y, subunit C4), has been shown to increase levels of leaf/seed protein without affecting the growth and yield of agronomic species. Here, we demonstrate that overexpression of AtQQS and NF‐YC4 in Arabidopsis and soybean enhances resistance/reduces susceptibility to viruses, bacteria, fungi, aphids, and soybean cyst ...


Understanding Anhydrous Ammonia Application In Soil, John E. Sawyer Jul 2019

Understanding Anhydrous Ammonia Application In Soil, John E. Sawyer

John E. Sawyer

What happens when anhydrous ammonia is injected into soil?

Several physical and chemical reactions take place following anhydrous ammonia injection: dissolution in water, reaction with soil organic matter and clay, and attachment of ammonium ions on the soil cation exchange complex. These reactions all tend to limit the movement of ammonia, with water having the greatest initial effect. The highest concentration of ammonia is at/near the point of injection, with a tapering of the concentration toward the outer edge of the retention zone. Usually the greatest ammonia concentration is within the first inch or two of the injection point ...


Flood Adulterated Grain - Nutrient Supply To Crops When Land Applied, John E. Sawyer, Antonio Mallarino Jul 2019

Flood Adulterated Grain - Nutrient Supply To Crops When Land Applied, John E. Sawyer, Antonio Mallarino

John E. Sawyer

Flooding has been extensive in several areas of Iowa this spring. In some cases, stored grain has been affected by flood waters. Land application of flood adulterated grain as a nutrient source for a future crop may be an option for some. See the Iowa Dept. of Natural Resources (IDNR) and Iowa Dept. of Agriculture and Land Stewardship (IDALS) publication for Proper Management of Flooded Grain and Hay. That publication states “Farms disposing of spoiled grain and feed on their own property can land apply damaged grain at the following application rates: 146 bu corn/acre and 50 bu soybean ...


Anhydrous Ammonia Application -- Spring 2019, John E. Sawyer Jul 2019

Anhydrous Ammonia Application -- Spring 2019, John E. Sawyer

John E. Sawyer

It was a late harvest in fall 2018. Soils were wet and frozen when it was time to apply anhydrous ammonia. Those situations resulted in much less than normal anhydrous ammonia application last fall. Therefore, considerable anhydrous ammonia needs to be applied this spring. There is only so much capacity to switch from one nitrogen (N) fertilizer product to another. In Iowa, historically the two largest N fertilizers are anhydrous ammonia (largest) and urea-ammonium nitrate (UAN) solution, with granulated urea a distant third.


Springtime Precipitation – A Tool For Estimating Nitrogen Application Need For Corn, John E. Sawyer Jul 2019

Springtime Precipitation – A Tool For Estimating Nitrogen Application Need For Corn, John E. Sawyer

John E. Sawyer

Wet springtime conditions typically raise questions about the status of applied nitrogen (N). Or the question, do I need to apply additional N to my cornfields? At this time we do not know what the weather/precipitation will be for the entire springtime, but the extended period of wet conditions this spring is of concern. A summary of long-term N rate trials with continuous corn and corn rotated with soybean conducted at seven ISU research and demonstration farms in Iowa from 1999 to 2016 has been an on-going basis for indicating the potential for needing an N rate greater than ...


Nitrogen Fertilization Options With Delayed Or Rescue Applications, John E. Sawyer Jul 2019

Nitrogen Fertilization Options With Delayed Or Rescue Applications, John E. Sawyer

John E. Sawyer

It’s been a wait-go-stop (repeat) corn planting season this spring. Whether you planted early or are just now getting corn planted, it seems planting windows were short and rushed. In some cases this meant planting (corn/soybean) and worrying later about getting nitrogen (N) applied. And in some areas of Iowa, wetter than normal conditions are raising questions about supplemental N application. What are the options for sidedress N?


Effects Of Unharvested, Shattered, Or Hailed-Out Soybean Fields On Nutrient Supply For Corn, John E. Sawyer Jul 2019

Effects Of Unharvested, Shattered, Or Hailed-Out Soybean Fields On Nutrient Supply For Corn, John E. Sawyer

John E. Sawyer

Flooded fields and wet soil conditions in the fall 2018 meant some soybean fields were not, or are not going to be harvested. Also, some fields occasionally experienced significant shattering or a hailstorm in the fall where soybean seed is knocked from the plants and thus not harvested. When the grain is not harvested, nitrogen (N), phosphorus (P), and potassium (K) nutrients returned to the soil in the soybean grain can be accounted for when planning nutrient applications for the next crop. Other nutrients will also be returned, but most are not a fertilization need in Iowa soils. An estimate ...


Transcriptome Analyses And Virus Induced Gene Silencing Identify Genes In The Rpp4 -Mediated Asian Soybean Rust Resistance Pathway, Aguida A.M.P. Morales, Jamie A. O'Rourke, Martijn Van De Mortel, Katherine T. Scheider, Timothy J. Bancroft, Aluizio Borem, Rex T. Nelson, Daniel S. Nettleton, Thomas J. Baum, Randy C. Shoemaker, Reid D. Frederick, Ricardo V. Abdelnoor, Kerry F. Pedley, Steven A. Whitham, Michelle Graham Jun 2019

Transcriptome Analyses And Virus Induced Gene Silencing Identify Genes In The Rpp4 -Mediated Asian Soybean Rust Resistance Pathway, Aguida A.M.P. Morales, Jamie A. O'Rourke, Martijn Van De Mortel, Katherine T. Scheider, Timothy J. Bancroft, Aluizio Borem, Rex T. Nelson, Daniel S. Nettleton, Thomas J. Baum, Randy C. Shoemaker, Reid D. Frederick, Ricardo V. Abdelnoor, Kerry F. Pedley, Steven A. Whitham, Michelle Graham

Dan Nettleton

Rpp4 (Resistance to Phakopsora pachyrhizi 4) confers resistance to Phakopsora pachyrhizi Sydow, the causal agent of Asian soybean rust (ASR). By combining expression profiling and virus induced gene silencing (VIGS), we are developing a genetic framework for Rpp4-mediated resistance. We measured gene expression in mock-inoculated and P. pachyrhizi-infected leaves of resistant soybean accession PI459025B (Rpp4) and the susceptible cultivar (Williams 82) across a 12-day time course. Unexpectedly, two biphasic responses were identified. In the incompatible reaction, genes induced at 12 h after infection (hai) were not differentially expressed at 24 hai, but were induced at 72 hai. In contrast, genes ...


Soybean Homologs Of Mpk4 Negatively Regulate Defense Responses And Positively Regulate Growth And Development, Jian-Zhong Liu, Heidi D. Horstman, Edward J. Braun, Michelle Graham, Chunquan Zhang, Duroy Navarre, Wen-Li Qiu, Yeunsook Lee, Dan Nettleton, John H. Hill, Steven A. Whitham Jun 2019

Soybean Homologs Of Mpk4 Negatively Regulate Defense Responses And Positively Regulate Growth And Development, Jian-Zhong Liu, Heidi D. Horstman, Edward J. Braun, Michelle Graham, Chunquan Zhang, Duroy Navarre, Wen-Li Qiu, Yeunsook Lee, Dan Nettleton, John H. Hill, Steven A. Whitham

Dan Nettleton

Mitogen-activated protein kinase (MAPK) cascades play important roles in disease resistance in model plant species such as Arabidopsis (Arabidopsis thaliana) and tobacco (Nicotiana tabacum). However, the importance of MAPK signaling pathways in the disease resistance of crops is still largely uninvestigated. To better understand the role of MAPK signaling pathways in disease resistance in soybean (Glycine max), 13, nine, and 10 genes encoding distinct MAPKs, MAPKKs, and MAPKKKs, respectively, were silenced using virus-induced gene silencing mediated by Bean pod mottle virus. Among the plants silenced for various MAPKs, MAPKKs, and MAPKKKs, those in which GmMAPK4 homologs (GmMPK4s) were silenced displayed ...


Parallel Genome-Wide Expression Profiling Of Host And Pathogen During Soybean Cyst Nematode Infection Of Soybean, Nagabhushana Ithal, Justin Recknor, Dan Nettleton, Leonard Hearne, Tom Maier, Thomas J. Baum, Melissa G. Mitchum Jun 2019

Parallel Genome-Wide Expression Profiling Of Host And Pathogen During Soybean Cyst Nematode Infection Of Soybean, Nagabhushana Ithal, Justin Recknor, Dan Nettleton, Leonard Hearne, Tom Maier, Thomas J. Baum, Melissa G. Mitchum

Dan Nettleton

Global analysis of gene expression changes in soybean (Glycine max) and Heterodera glycines (soybean cyst nematode [SCN]) during the course of infection in a compatible interaction was performed using the Affymetrix GeneChip soybean genome array. Among 35,611 soybean transcripts monitored, we identified 429 genes that showed statistically significant differential expression between uninfected and nematode-infected root tissues. These included genes encoding enzymes involved in primary metabolism; biosynthesis of phenolic compounds, lignin, and flavonoids; genes related to stress and defense responses; cell wall modification; cellular signaling; and transcriptional regulation. Among 7,431 SCN transcripts monitored, 1,850 genes showed statistically significant ...


Sequence Mining And Transcript Profiling To Explore Cyst Nematode Parasitism, Axel A. Elling, Makedonka Mitreva, Xiaowu Gai, John Martin, Justin Recknor, Eric L. Davis, Richard S. Hussey, Dan Nettleton, James P. Mccarter, Thomas J. Baum Jun 2019

Sequence Mining And Transcript Profiling To Explore Cyst Nematode Parasitism, Axel A. Elling, Makedonka Mitreva, Xiaowu Gai, John Martin, Justin Recknor, Eric L. Davis, Richard S. Hussey, Dan Nettleton, James P. Mccarter, Thomas J. Baum

Dan Nettleton

Background: Cyst nematodes are devastating plant parasites that become sedentary within plant roots and induce the transformation of normal plant cells into elaborate feeding cells with the help of secreted effectors, the parasitism proteins. These proteins are the translation products of parasitism genes and are secreted molecular tools that allow cyst nematodes to infect plants.

Results: We present here the expression patterns of all previously described parasitism genes of the soybean cyst nematode, Heterodera glycines, in all major life stages except the adult male. These insights were gained by analyzing our gene expression dataset from experiments using the Affymetrix Soybean ...


Maize Inbreds Exhibit High Levels Of Copy Number Variation (Cnv) And Presence/Absence Variation (Pav) In Genome Content, Nathan M. Springer, Kai Ying, Yan Fu, Tieming Ji, Cheng-Ting Yeh, Yi Jia, Wei Wu, Todd Richmond, Jacob Kitzman, Heidi Rosenbaum, A. Leonardo Iniguez, W. Brad Barbazuk, Jeffrey A. Jeddeloh, Daniel S. Nettleton, Patrick S. Schnable Jun 2019

Maize Inbreds Exhibit High Levels Of Copy Number Variation (Cnv) And Presence/Absence Variation (Pav) In Genome Content, Nathan M. Springer, Kai Ying, Yan Fu, Tieming Ji, Cheng-Ting Yeh, Yi Jia, Wei Wu, Todd Richmond, Jacob Kitzman, Heidi Rosenbaum, A. Leonardo Iniguez, W. Brad Barbazuk, Jeffrey A. Jeddeloh, Daniel S. Nettleton, Patrick S. Schnable

Dan Nettleton

Following the domestication of maize over the past ∼10,000 years, breeders have exploited the extensive genetic diversity of this species to mold its phenotype to meet human needs. The extent of structural variation, including copy number variation (CNV) and presence/absence variation (PAV), which are thought to contribute to the extraordinary phenotypic diversity and plasticity of this important crop, have not been elucidated. Whole-genome, array-based, comparative genomic hybridization (CGH) revealed a level of structural diversity between the inbred lines B73 and Mo17 that is unprecedented among higher eukaryotes. A detailed analysis of altered segments of DNA conservatively estimates that ...


Flor Revisited (Again): Eqtl And Mutational Analysis Of Nb-Lrr Mediated Immunity To Powdery Mildew In Barley, Roger P. Wise, Priyanka Surana, Gregory S. Fuerst, Ruo Xu, Divya Mistry, Julie A. Dickerson, Dan Nettleton Dr. Jun 2019

Flor Revisited (Again): Eqtl And Mutational Analysis Of Nb-Lrr Mediated Immunity To Powdery Mildew In Barley, Roger P. Wise, Priyanka Surana, Gregory S. Fuerst, Ruo Xu, Divya Mistry, Julie A. Dickerson, Dan Nettleton Dr.

Dan Nettleton

Genes encoding early signaling events in pathogen defense often are identified only by their phenotype. Such genes involved in barley-powdery mildew interactions include Mla, specifying race-specific resistance; Rar1 (Required for Mla12-specified resistance1), and Rom1 (Restoration of Mla-specified resistance1). The HSP90-SGT1-RAR1 complex appears to function as chaperone in MLA-specified resistance, however, much remains to be discovered regarding the precise signaling underlying plant immunity. Genetic analyses of fast-neutron mutants derived from CI 16151 (Mla6) uncovered a novel locus, designated Rar3 (Required for Mla6-specified resistance3). Rar3 segregates independent of Mla6 and Rar1, and rar3 mutants are susceptible to Blumeria graminis f. sp. hordei ...


Biphasic Gene Expression Changes Elicited By Phakopsora Pachyrhizi In Soybean Correlate With Fungal Penetration And Haustoria Formation, Katherine T. Schneider, Martijn Van De Mortel, Timothy J. Bancroft, Edward J. Braun, Dan Nettleton, Rex T. Nelson, Reid D. Frederick, Thomas J. Baum, Michelle Graham, Steven A. Whitham Jun 2019

Biphasic Gene Expression Changes Elicited By Phakopsora Pachyrhizi In Soybean Correlate With Fungal Penetration And Haustoria Formation, Katherine T. Schneider, Martijn Van De Mortel, Timothy J. Bancroft, Edward J. Braun, Dan Nettleton, Rex T. Nelson, Reid D. Frederick, Thomas J. Baum, Michelle Graham, Steven A. Whitham

Dan Nettleton

Inoculation of soybean (Glycine max) plants with Phakopsora pachyrhizi, the causal organism of Asian soybean rust, elicits a biphasic response characterized by a burst of differential gene expression in the first 12 h. A quiescent period occurs from 24 to 48 h after inoculation, in which P. pachyrhizi continues to develop but does not elicit strong host responses, followed by a second phase of intense gene expression. To correlate soybean responses with P. pachyrhizi growth and development, we inoculated the soybean cultivar Ankur (accession PI462312), which carries the Rpp3 resistance gene, with avirulent and virulent isolates of P. pachyrhizi. The ...


Distinct Biphasic Mrna Changes In Response To Asian Soybean Rust Infection, Martijn Van De Mortel, Justin C. Recknor, Michelle Graham, Dan Nettleton, Jaime D. Dittman, Rex T. Nelson, Claudia V. Godoy, Ricardo V. Abdelnoor, Alvaro M.R. Almeida, Thomas J. Baum, Steven A. Whitham Jun 2019

Distinct Biphasic Mrna Changes In Response To Asian Soybean Rust Infection, Martijn Van De Mortel, Justin C. Recknor, Michelle Graham, Dan Nettleton, Jaime D. Dittman, Rex T. Nelson, Claudia V. Godoy, Ricardo V. Abdelnoor, Alvaro M.R. Almeida, Thomas J. Baum, Steven A. Whitham

Dan Nettleton

Asian soybean rust (ASR), caused by Phakopsora pachyrhizi, is now established in all major soybean-producing countries. Currently, there is little information about the molecular basis of ASR–soybean interactions, which will be needed to assist future efforts to develop effective resistance. Toward this end, abundance changes of soybean mRNAs were measured over a 7-day ASR infection time course in mock-inoculated and infected leaves of a soybean accession (PI230970) carrying the Rpp2 resistance gene and a susceptible genotype (Embrapa-48). The expression profiles of differentially expressed genes (ASR-infected compared with the mock-inoculated control) revealed a biphasic response to ASR in each genotype ...


Developmental Transcript Profiling Of Cyst Nematode Feeding Cells In Soybean Roots, Nagabhushana Ithal, Justin Recknor, Dan Nettleton, Tom Maier, Thomas J. Baum, Melissa G. Mitchum Jun 2019

Developmental Transcript Profiling Of Cyst Nematode Feeding Cells In Soybean Roots, Nagabhushana Ithal, Justin Recknor, Dan Nettleton, Tom Maier, Thomas J. Baum, Melissa G. Mitchum

Dan Nettleton

Cyst nematodes of the genus Heterodera are obligate, sedentary endoparasites that have developed highly evolved relationships with specific host plant species. Successful parasitism involves significant physiological and morphological changes to plant root cells for the formation of specialized feeding cells called syncytia. To better understand the molecular mechanisms that lead to the development of nematode feeding cells, transcript profiling was conducted on developing syncytia induced by the soybean cyst nematode Heterodera glycines in soybean roots by coupling laser capture microdissection with high-density oligonucleotide microarray analysis. This approach has identified pathways that may play intrinsic roles in syncytium induction, formation, and ...


Comparison Of Transcript Profiles In Wild-Type And O2 Maize Endosperm In Different Genetic Backgrounds, Hongwu Jia, Dan Nettleton, Joan M. Peterson, Gricelda Vasquez-Carrillo, Jean-Luc Jannink, M. Paul Scott Jun 2019

Comparison Of Transcript Profiles In Wild-Type And O2 Maize Endosperm In Different Genetic Backgrounds, Hongwu Jia, Dan Nettleton, Joan M. Peterson, Gricelda Vasquez-Carrillo, Jean-Luc Jannink, M. Paul Scott

Dan Nettleton

Mutations in the Opaque2 (O2) gene of maize (Zea mays L.) improve the nutritional value of maize by reducing the level of zeins in the kernel. The phenotype of o2 grain is controlled by many modifier genes and is therefore strongly dependent on genetic background. We propose two hypotheses to explain differences in phenotypic severity in different genetic backgrounds: (i) Specific genes are differentially (o2 vs. wild-type) expressed only in certain genotypes, and (ii) A set of genes are differentially expressed in all backgrounds, but the degree of differential expression differs in different backgrounds. To determine the extent to which ...


A Diallel Analysis Of A Maize Donor Population Response To In Vivo Maternal Haploid Induction I: Inducibility, Gerald N. De La Fuente, Ursula K. Frei, Benjamin Trampe, Daniel Nettleton, Wei Zhang, Thomas Lubberstedt Jun 2019

A Diallel Analysis Of A Maize Donor Population Response To In Vivo Maternal Haploid Induction I: Inducibility, Gerald N. De La Fuente, Ursula K. Frei, Benjamin Trampe, Daniel Nettleton, Wei Zhang, Thomas Lubberstedt

Dan Nettleton

The maize in vivo maternal doubled haploid (DH) system is an important tool used by maize breeders and geneticists around the world. The ability to rapidly produce DH lines of maize for breeding allows breeders to quickly respond to new selection criteria based on the ever changing biotic and abiotic stresses that maize is subjected to across its growing area. There are two important steps in the generation of DH lines using the in vivo maternal DH system: 1) the production and identification of haploid progeny, and 2) the doubling of genomes to create fertile, diploid inbred lines that can ...


Using Drones For Precision Agriculture, Jiyul Chang, Madhav P. Nepal May 2019

Using Drones For Precision Agriculture, Jiyul Chang, Madhav P. Nepal

Madhav Nepal

In this teaching module, students will learn what Precision Agriculture is and how to apply drone into Precision Agriculture practices. To use data (images) taken by drone, students will learn the basic theory of Remote Sensing. Using images, students learn how to make NDVI (Normalized Difference Vegetation Index) maps and how to apply drone (remote sensing technique) in agriculture.


Medicago Sativa Has Reduced Biomass And Nodulation When Grown With Soil Microbiomes Conditioned To High Phosphorus Inputs, Laura M. Kaminsky, Grant L. Thompson, Ryan V. Trexler, Terrence H. Bell, Jenny Kao-Kniffin Feb 2019

Medicago Sativa Has Reduced Biomass And Nodulation When Grown With Soil Microbiomes Conditioned To High Phosphorus Inputs, Laura M. Kaminsky, Grant L. Thompson, Ryan V. Trexler, Terrence H. Bell, Jenny Kao-Kniffin

Grant Thompson

Agricultural over-fertilization may adversely impact plant−microbial interactions affecting crop yield. It is unclear if soil microbiomes respond quickly to changes in fertilizer inputs once conditioned to specific nutrient regimes. We conducted a growth chamber study assessing the compositional and functional resilience of root-associated microbiomes of Medicago sativa to nutrient regime changes, and consequences for plant growth. Plants were grown with a common starting soil microbiome under four nutrient treatments: control (no fertilizer), organic phosphorus (compost added), low inorganic P (low triple superphosphate, TSP) and high inorganic P (high TSP). After several conditioning generations, in which microbiomes from rhizospheres of ...


Farmer Decision Making Strategies For Improved Soil Fertility Management In Maize-Bean Production Systems, Robert Mazur, Moses Tenywa, Richard Miiro, Onesmus Semalulu, Ricardo Maria, Sostino Mocumbe, Eric Abbott, Andrew Lenssen, Ebby Luvaga, Bradley Miller, Lee Burras, Russell Yost, Julia Bello-Bravo, Barry Pittendrigh Jan 2019

Farmer Decision Making Strategies For Improved Soil Fertility Management In Maize-Bean Production Systems, Robert Mazur, Moses Tenywa, Richard Miiro, Onesmus Semalulu, Ricardo Maria, Sostino Mocumbe, Eric Abbott, Andrew Lenssen, Ebby Luvaga, Bradley Miller, Lee Burras, Russell Yost, Julia Bello-Bravo, Barry Pittendrigh

Andrew W. Lenssen

Following completion of research experiments on common bean in Uganda, five rainy seasons of community-based field trials enabled farmers to learn about and evaluate improved management practices and technologies for adoption. A multistakeholder bean Innovation Platform continues to develop in membership size, diversity, enthusiasm and capability, with 10 value chain member organizations and 1000+ farmers. In Mozambique, field experiments were completed mid-2017 by IIAM. Two SAWBO video animations were released on research-based farmer-validated bean production recommendations in Uganda and Mozambique and one on jerry can storage for Mozambique. IIAM created and is field testing its first App, focused on bean ...


Narrow Rows May Lift Bean Yield, Mark Licht, Andrew Lenssen Jan 2019

Narrow Rows May Lift Bean Yield, Mark Licht, Andrew Lenssen

Andrew W. Lenssen

Soybean row spacing: What is optimum for today’s production systems? Row spacing used by soybean farmers in Iowa has varied from 6 to 40 inches. What row spacing should you consider if you are contemplating buying a new planter for soybeans? Can narrower row spacing improve yield and profitability?


Supply Chains In Sub‐Saharan Africa: A Decision Support System For Small‐Scale Seed Entrepreneurs, Bobby J. Martens, Kevin P. Scheibe, Paul K. Bergey Jul 2018

Supply Chains In Sub‐Saharan Africa: A Decision Support System For Small‐Scale Seed Entrepreneurs, Bobby J. Martens, Kevin P. Scheibe, Paul K. Bergey

Kevin P. Scheibe

It is necessary to infuse a consistent supply of improved seed varieties into local sub‐Saharan African crop production to improve low crop yields. The best distribution channel for the improved seed varieties may be small‐scale commercial seed companies, but local entrepreneurs struggle to determine whether such businesses are viable. Using a multi‐echelon supply chain approach, a decision support system (DSS) was designed to help African seed entrepreneurs make informed decisions about small‐scale seed chain businesses. Specifically, entrepreneurs make decisions about where to locate seed enterprises, with which farmers to contract, and where to store seed. Optimization ...


Qqs Orphan Gene And Its Interactor Nf‐Yc4 Reduce Susceptibility To Pathogens And Pests, Mingsheng Qi, Wenguang Zheng, Xuefeng Zhao, Jessica D. Hohenstein, Yuba Kandel, Seth O’Conner, Yifan Wang, Chuanlong Du, Dan Nettleton, Gustavo C. Macintosh, Gregory L. Tylka, Eve Syrkin Wurtele, Steven A. Whitham, Ling Li Jun 2018

Qqs Orphan Gene And Its Interactor Nf‐Yc4 Reduce Susceptibility To Pathogens And Pests, Mingsheng Qi, Wenguang Zheng, Xuefeng Zhao, Jessica D. Hohenstein, Yuba Kandel, Seth O’Conner, Yifan Wang, Chuanlong Du, Dan Nettleton, Gustavo C. Macintosh, Gregory L. Tylka, Eve Syrkin Wurtele, Steven A. Whitham, Ling Li

Gustavo Macintosh

Enhancing the nutritional quality and disease resistance of crops without sacrificing productivity is a key issue for developing varieties that are valuable to farmers and for simultaneously improving food security and sustainability. Expression of the Arabidopsis thaliana species‐specific AtQQS (Qua‐Quine Starch) orphan gene or its interactor, NF‐YC4 (Nuclear Factor Y, subunit C4), has been shown to increase levels of leaf/seed protein without affecting the growth and yield of agronomic species. Here, we demonstrate that overexpression of AtQQS and NF‐YC4 in Arabidopsis and soybean enhances resistance/reduces susceptibility to viruses, bacteria, fungi, aphids, and soybean cyst ...