NCSRP Production Research
The NCSRP Board approved the following research projects for funding in 2013/2014. Several of the projects are being jointly funded by the United Soybean Board and state checkoff boards.
The areas emphasized for the coming year are soybean diseases, soybean cyst nematode, the soybean aphid, genetic and biotechnology studies toward the improvement of host resistance, and technology transfer/communication programs.
The NCSRP Board is confident that successful completion of the individual projects will significantly advance the understanding of some of the region’s major soybean production problems.
Projects funded for 2013 (summaries follow):
- Soybean Aphid Management, Resistance and Outreach in the North-Central Region
- Developing an Integrated Management and Communication Plan for Soybean Sudden Death Syndrome (SDS) in the North-Central Region
- Breeding to Improve Resistance to SDS in Soybean as a Means to Protect Yield – Delivering Resistant Varieties and Lines
- Increasing Profits Through Genetic Resistance to SDS
- Development of a Biological Control Product to Control Sudden Death Syndrome and White Mold
- Identification and Biology of Seedling Pathogens
- Iron Deficiency Chlorosis: Getting to the Root of the Problem
- Disease Study Group: Focus on New and Emerging Soybean Diseases
- Improving the Awareness and Management of Charcoal Rot of Soybean in the North-Central Region
- Enhancing Disease Resistance Through the Tools of Biotechnology
- Mapping Genes Conferring Resistance to Soybean White Mold
- The use of VIGS technology to decrease yield-limiting stress in soybeans
- Engineered resistance to soybean cyst nematode via induced gene silencing (RNAi)
- Understanding cover crop use in soybean production systems
- Plant Health Initiative
Summary of current projects
To date, at least four different genes have been isolated. The first gene to be identified, named Rag1, was found by USDA scientists and tested in 5 midwestern states in 2009. Commercial varieties are now on the market.
1. Soybean Aphid Management, Resistance and Outreach in the North Central Region
This is a coordinated regional soybean aphid research program on the management of the soybean aphid through classic biological control and host plant resistance.
The project provides for a network of collaborating entomologists, plant breeders, and Extension specialists in twelve states to develop answers to complex issues facing soybean growers in managing the soybean aphid.
- Study chemical control and resistant variety interactions. The specific studies involve developing appropriate thresholds for resistant varieties, establishing treatment thresholds for late R5 and R6 soybeans; modeling and sampling aphid populations; and field-screening promising soybean breeding lines;
- Study the interaction of genetically-resistant varieties and biocontrol agents. The researchers will establish how natural enemies affect aphid population doubling time on Rag1 resistant lines; and determine whether susceptible lines are used as refuges for predators;
- Expand biological control studies. These studies involve host range testing, release, and follow-up monitoring of the aphid predators;
- Study the mechanisms of plant resistance with specific attention to plant response to aphid feeding and functional plant genomics; and
- Develop and publish soybean aphid management guidelines for susceptible and aphid-resistant soybean lines.
Chlamydospores (overwintering structure) of Fusarium viguliforme, the SDS pathogen.
2. Developing an Integrated Management and Communication Plan for Soybean Sudden Death Syndrome (SDS) in the North-Central Region
The foundational management strategy for SDS is resistant cultivars. However, in some years when environmental conditions are especially favorable for SDS, it's been evident that resistance alone does not provide adequate control. The main goal of this project is to develop crop managment strategies that will ensure that SDS-resistant cultivars will be effective as possible.
This research project has a direct benefit to soybean farmers in the north-central region by providing evaluation of current and future crop production practices and/or products, how these practices fit into an IPM strategy for SDS and if they enhance the efficacy of SDS-resistant sobyean cultivars.
- Determine the most effective diagnostic protocol for quantfying Fusarium virguliforme, the SDS pathogen, in roots and in soil.
- Evaluate if soybean root health can be improved to reduce SDS or be used as an indicator of SDS risk.
- shifts in soybean production practices affect the risk of SDS development.
- Communicate research results with farms, agribusinesses and other soybean stakeholders.
Planting resistant varieties is the key to managing SDS. Here a comparison of SDS-resistant varieties on either side of a susceptible variety.
3. Breeding to Improve Resistance to SDS in Soybean as a Means to Protect Yield – Delivering Resistant Varieties and Lines
The project draws upon the expertise of a multi-state group of researchers who are collaborating closely to develop varieties and breeding lines with SDS resistance. The goal is to deliver SDS-resistant soybean varieties to farmers, and experimental lines to the seed industry for breeding. Varieties and lines will be developed for maturity groups I to VI.
Up to now, breeders have been mostly working independently, with funds provided by state check-off funds. This has the drawback that promising genetic lines are generally not exchanged among researchers until the time of releasing the new material, often after 8 to 10 years of work. By the close collaboration established in this project, researchers have first-hand knowledge of promising lines early in their development, reducing the time from crossing to the release of public lines.
The work will also be facilitated by having one lab conduct screening of all experimental lines within a maturity group for SDS resistance, and having another lab screen the germplasm in National Soybean Collection and provide the results directly to breeders.
- Breed soybean cultivars and lines in Maturity Groups I to VI , and release them for use by farmers and breeding programs
- Evaluate the SDS resistance of plant introduction from the National Soybean Germplasm Collection
- Evaluate the breeding lines for SDS resistance to expedite breeding process and selection
- Evaluate advanced experimental lines from the Regional Soybean Tests, coordinated by USDA-ARS
Symptoms of SDS on soybean leaves.
4. Increasing Profits Through Genetic Resistance to SDS
Some soybean cultivars show good resistance to SDS, however, the inheritance of this resistance is complex because it is controlled by many genes. Improving our understanding of the genetic basis of resistance will help breeders become more efficient in developing new, high-yielding SDS-resistant cultivars.
This project focuses on the genetic basis of SDS resistance. The research spans from fairly basic research on the expression of genes in response to SDS infection to the more applied mapping and confirming of the genetic locations of resistance genes. The SDS resistance genes and marker technology developed in this project will be shared with the other SDS breeding projects and made available to public and commercial breeders.
Rhizoctonia was not able to grow in the top part of the dish which was treated with the bacterial biocontrol agent, compared to the untreated bottom half.
5. Development of a Biological Control Product to Control Sudden Death Syndrome (SDS) and White Mold
In the past few years, several new biological fungicides have been marketed or are in development in private industry that are reported to be effective in controlling SDS and/or white mold. These biological control agents are easy to reproduce and can be applied to soil as a bio-fungicide before planting. They are reported to establish in soil, killing the SDS and white mold fungus, and preventing new infection from occurring. In this study, we are conducting regional field tests in Iowa, Illinois, and Minnesota to test the
effectiveness of these products as well as an experimental biocontrol agent isolated from Iowa soil.
Field experiments will be conducted to determine if the application of the biocontrol agent to crop residues of corn, alfalfa, or soybean can reduce inoculum production, infection, and disease caused by F. virguliforme (causal agent of SDS) and Sclerotinia (causal agent of white mold).
We are also studying a soil-borne bacterium which has both lytic and micropredatory activity on a variety of fungi. Our initial screening has indicated that this bacterium can suppress and kill Pytophthora, and the causal pathogens of SDS, white mold, seedling diseases, and Rhizoctonia root rot. Because fermentation of a bacterium is simple and inexpensive, this agent has good commercial potential to be an effective biological fungicide for a spectrum of soybean fungal diseases.
- To conduct multi-state field evaluation of commercial biological control agents on their ability to reduce soybean SDS and soybean white mold
- To investigate a new bacterial biocontrol agent that has shown efficacy in controlling SDS and soybean white mold and investigate the potential for commercialization.
- To determine if the application of the biocontrol agent to crop residues of corn, alfalfa, or soybean can reduce inoculums production, infection, and disease caused by F. virguliforme and Sclerotinia
Soybean seedlings at emergence. Photo credit: University of Nebraska
6. Identification and Biology of Seedling Pathogens
Producing high soybean yields begins with establishing an even stand of vigorous plants. As seed prices rise, producers plant fewer seed per acre and depend on a higher percentage of their seed emerging than ever before. Therefore, understanding how to prevent seedling diseases and root rot has become even more important.
Although seedling pathogens are known and understood in some production areas, there is often a complex of pathogens involved. The disease complexes are composed primarily of "water molds", Pythium and Phytophthora, and the fungi Fusarum spp. and Rhizoctonia solani.
There is limited information about the optimum conditions that favor infection by the different species present in these seedling disease complexes. Understanding,which specific pathogen make up the seedlig disease complex, and the factors that enhance the damage they cause will increase our understanding of seedling diseases and help develop better management strategies.
- Identify fungi responsible for causing seedling blights of soybean
- Develop high throughput diagnostic tools for identifying fungal seeding pathogens
- Characterize the biology of seedling pathogens and develop assays for inoculation
- Identify the impact of environmental conditions on seedling pathogens.
Soybean field showing symptoms of iron deficiency chlorosis. Photo credit: R.J. Goos, North Dakota State University
7. Iron Deficiency Chlorosis: Getting to the Root of the Problem
Iron deficiency chlorosis (IDC) occurs in the interveinal tissue of young leaves when iron is unavailable to the plant. This is a common problem for soybeans grown on the calcareous soils in the north central states of the US where high pH reduces iron availability to the plant. This availability is further reduced under the wet spring conditions due to the interaction of calcium carbonate with the soil. This results in early season IDC symptoms that are so damaging to yield.
In addition to the soil availability issue, not all varieties have the same ability to metabolize iron because of their different genetic makeup. Efficient plants can reduce the pH near their roots in a manner that releases iron. They also can convert the iron into a state that can be taken up by the root iron transport system and transfer the iron through the root system to the xylem where it binds to a carrier and is transported to leaves. Once it reaches the leaf, it must be unloaded into the cell and form a complex with the key components of the photosynthesis system. It is obvious from this brief summary that multiple genes must function properly to prevent IDC.
The goals of this project is to continue and refine our search for molecular markers and identification of candidate genes associated with iron deficiency (IDC) tolerance in soybean using state-of-the-art genomic technologies. The markers and genes will then be applied to breeding programs in a manner that leads to IDC-tolerant soybean varieties.
- Utilize genotype-by-sequencing and genomic selection procedures to broaden the number of markers associated with IDC tolerance in soybean and test those in breeding programs
- Further refine the region associated with IDC tolerance on chromosome 3 to better understand the mechanisms of IDC tolerance
- Continue the evaluation of transgenic plants containing targeted genes involved in iron metabolism to determine their role in IDC tolerance
Foliar symptoms of Soybean Vein Necrosis Virus, a widespread disease across the Midwest in 2012.
8. Disease Study Group: Focus on New and Emerging Soybean Diseases
Changes in crop production practices and environment impact disease severity and prevalence each year. There are diseases that are an annual threat, such as sudden death syndrome (SDS) and soybean cyst nematode (SCN), but many other diseases are sporadic, new, or emerging in the north-central region.
In a traditional system, research is conducted and Extension materials are developed and disseminated at the end of the project. This creates a “gap” in industry and farmer awareness for emerging diseases, and prevents stakeholders from obtaining the most current information about emerging issues until research projects can be completed.
The North Central Disease Study Group, made up of six core collaborators in five midwestern states and Ontario, Canada, will bridge the gap between research and Extension for emerging disease threats and provide industry and farmers with the most up-to-date information available about emerging diseases each year. In 2013 the focus will be Extension materials for soybean viruses, including Soybean Vein Necrosis Virus (SVNV), which was widely distributed across the north-central region in 2012, and of which there is little Extension information currently available for stakeholder use.
- Organize a core group of Extension personnel to annually identify and develop Extension
material for new or emerging (endemic) diseases
- Provide information on multiple levels of Extension interface (print, web, video,
smartphone, etc.) to reach diverse groups of stakeholders
- Provide current research summaries on emerging diseases to direct and coordinate future
research priorities, thereby minimizing duplication, maximizing resources and increasing
Death of young plant due to charcoal rot infection under extreme heat and drought conditions.
Photo credit: Chris Little, Kansas State University.
9. Improving the Awareness and Management of Charcoal Rot of Soybean in the North-Central Region
Until more recently, M. phaseolina, the causal pathogen of charcoal rot, was considered a southern soybean pathogen and an infequent pathogen of soybean in the North Central production region. Increased incidence of charcoal rot on soybean in the North Central regional is likely a result of weather trends toward warmer summer temperatures and reduced rainfall, conditions that favor the disease.
- Establish field demonstration plots in each participating state to increase grower awareness of charcoal rot of soybean and showcase best management practices (BMPs) for the disease in the North Central region.
- Develop new and up-to-date outreach materials including fact sheets, podcasts, webpages, and video clips pertaining to charcoal rot of soybean and showcasing the best management practices for charcoal rot in the Midwest.
10. Enhancing Disease Resistance in Soybean Through the Tools of Biotechnology
Our research is contributing to the control of three main soybean viruses, namely bean pod mottle virus (BPMV), soybean mosaic virus (SMV) and alfalfa mosaic virus (AMV), leading to improved yield of soybean seed.
Previous funding from NCSRP has allowed us to successfully develop novel transgenic soybeans that confer resistance to these three viruses with one single transgene. These transgenic soybean lines have been tested in both Nebraska and Ohio, under both greenhouse and field conditions, and shown to be highly resistant to the three viruses.
The information gathered from continued field trials will provide more accurate estimates on the yield losses caused by these three viruses, and provide a multi-year assessment of the stability of the resistance phenotype. These data will provide the basis for estimating the potential value of a multi-virus resistance trait in soybean, which is a critical step towards pursuing commercialization of the transgenic traits.
- Determine the long-term agronomic performance and the stability of the resistance phenotype of the transgenic soybean expressing a multi-viral resistance trait
- Test the effectiveness of transgenically-expressed small interfering RNAs (siRNAs) and micro RNAs (miRNAs) in conferring resistance to soybean aphid in soybean.
11. Mapping Genes Conferring Resistance to Soybean White Mold
The proposed project builds on the current project funded by NCSRP that resulted in the development of W04-1002, an experimental line with a high level of resistance to white mold. W04-1002 is an inbred line derived from PI 567157A by selection for plant survival after inoculation with S. sclerotiorum. W04-1002 expresses 90 to 100% survival after repeated challenges with multiple isolates of S. sclerotiorum in greenhouse trials.
W04-1002 was crossed with four parents that were rated as susceptible to white mold in 2006. These parents include W04-571, a selection from the cross Dwight x PI 567479, and W04-680, a selection from the cross Dwight x PI 567479. These were selected on the basis of good agronomic traits and resistance to brown stem rot (BSR) and soybean cyst nematode (SCN).
Currently, 138 lines express 0% mortality after challenge with the white mold pathogen. There are currently 115 lines for Population 4 (W04-571 x W04-1002), 116 lines for Population 5 (W04-680 x W04-1002), 222 lines for Population 8 (L84-5873 x W04-1002) and 196 lines for Population 9 (LN89-5717 x W04-1002) for a total of 649 lines.
- Build on these past results by completing the mapping of genes controlling white mold resistance in these populations. This research is especially important to complete because these populations are a unique resource developed from long term research.
- The mapping will be completed by testing all lines in the four populations with markers from the genetic regions where markers were identified as associated with resistance in the preliminary tests.
- Provide the locations of these genes to breeders who can then increase their success in developing highly resistant experimental lines. These selected lines can be used as resistant varieties by soybean growers and as parents in further breeding efforts.
12. The use of VIGS technology to decrease yield-limiting stress in soybeans
The project’s goal is to understand the genetic pathways involved in resistance to biotic and aboitic stress. With this understanding, soybean germplasm can be developed with features that respond less to variation in growing conditions.
The VIGS technology uses bean pod mottle virus to carry pieces of soybean gene sequences into the plant to turn off (silence) requisite target genes. In this technology, a piece of a soybean gene is placed in the BPMV virus vector and inserted in the soybean genome. VIGS technology allows for rapid screening and assessing the function of the genes being tested.
13. Engineered resistance to soybean cyst nematode via induced gene silencing (RNAi)
Previous research has shown that turning off genes by a process known as RNA interference (RNAi) has tremendous potential as a new strategy to increase nematode resistance. This project will investigate the possibility of inserting target gene sequences into the nematodes to obtain durable genetic material lethal to SCN populations.
The researchers will engineer stable transgenic soybean plants with traits that can silence specific nematode genes, evaluate transgenic lines with SCN bioassays to confirm the effectiveness of the level of SCN resistance, and examine the durability of the transgenic traits on single and diverse populations of SCN.
14. Understanding cover crop use in soybean production systems
The goal of this research project is to increase the Midwest soybean grower understanding of the use of cover crops in their production systems. Cover crops can provide benefits to soil health and fertility, pest and disease suppression, nutrient management and improved soybean yields and profitability.
Collaborating with members of the Midwest Cover Crop Council and other interested researchers, the team will produce a management guide for North Central Region farmers on the use of cover crops in soybean production systems. A secondary objective will be to review the current knowledge on the use of cover crops in the North Central Region and develop a prioritized list of cover crop research needs
Management of White Mold, an NCSRP publication resulting from collaborative, multi-state research.
NCSRP's outreach goal is to increase grower awareness of solutions for disease and insect problems by transferring knowledge gained from checkoff-funded activities to soybean producers through the electronic and print media.
- Provide science-based information to soybean producers that can be used to reduce soybean yield loss from disease and insects;
- Sponsor conferences and workshops that highlight soybean disease research topics;
- Develop educational materials that will help soybean growers better manage soybean diseases and pests; and
- Facilitate and coordinate research and information transfer between industry, university, media and Midwest soybean growers.