Last year, aphid infestation on soybean was high enough that many growers had to spray their fields to control aphids. Despite this, many aphids survived and took flight last fall causing a public nuisance. Migrating soybean aphids have delayed Major League baseball games, closed outdoor cafes and curtailed outdoor activities.
The soybean aphid is the only soybean insect pest known to have multiple biotypes, said Glen Hartman, U of I professor of crop sciences and USDA research plant pathologist. When farmers plant aphid-resistant soybean varieties, they provide protection against Biotype 1. However, recent research indicates that Biotype 2, which was first discovered in 2006, can overcome some aphid-resistant varieties.
The most recently identified soybean aphid, Biotype 3, was discovered in Springfield Fen, Ind., on an overwintering host, glossy buckthorn. Biotype 3 has not been found outside of this location to date and is not distinguishable by its appearance.
Researchers identified Biotype 3 by testing this aphid on soybean plants with known resistance genes. They found it was capable of feeding and multiplying on varieties carrying the resistance genes Rag1 and Rag2.
"Identifying a biotype that can overcome Rag1 and Rag2 resistance, even before soybean varieties with these resistance genes were deployed in production, suggests high variability in virulence within soybean aphid populations," said Curt Hill, U of I principal research specialist. "This gives the pest a high potential to adapt to and reduce the effective life of resistance genes deployed in production."
What does this mean for soybean farmers? A limited number of soybean varieties carrying the Rag1 resistance gene were planted in 2009, and more varieties are now available. The discovery of an aphid biotype that can overcome the gene means breeders and seed companies will need to keep pace with the pest.
Hartman recommends that farmers should plant aphid-resistant varieties if they have experienced aphid problems in the past. In addition, farmers should closely monitor aphid populations in their fields and spray when populations reach the economic threshold level, approximately 250 aphids per plant. If farmers find threshold populations on resistant varieties, they should contact their local Extension agent.
Fortunately aphid infestations can easily be controlled with insecticides, Hill said. However the question of timing becomes a key factor that requires scouting of fields and entomologist recommendations regarding threshold levels. Hartman said farmers can save some of their yield if they follow guidelines found in U of I Extension literature.
"Soybean aphids have a closer relationship with their host than other bugs," Hill said. "They can feed on other plants, but they only readily reproduce during the summer months on soybean. They suck all of the life out of the plant in a matter of weeks, causing tremendous yield loss for farmers. This makes scouting crucial."
U of I researchers are continuing to look for new resistance genes while studying the genomics of the soybean aphid to better understand its virulence. Hill believes plant resistance can provide an effective, economical and sustainable method of insect control.
"We hope the use of molecular markers to identify biotypes will be available soon so we can take samples in the field and perform quick DNA tests to determine distribution of these biotypes," Hill said. "Our goal is to help the soybean seed industry determine where to market soybean varieties with particular soybean aphid resistance genes to ultimately help producers select appropriate resistant varieties based on the virulence potential in their area."
This research was published in the Journal of Economic Entomology and funded by the United Soybean Board. The research team included Curt Hill, Laura Crull, Theresa Herman, Glen Hartman and David Voegtlin at the U of I.
Digital photos available at: http://www.aces.uiuc.edu/news/News_Photos/SoybeanAphid/
Jennifer Shike | EurekAlert!
Chips, light and coding moves the front line in beating bacteria
16.08.2018 | Okinawa Institute of Science and Technology (OIST) Graduate University
Protein droplets keep neurons at the ready and immune system in balance
16.08.2018 | Howard Hughes Medical Institute
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
16.08.2018 | Earth Sciences
16.08.2018 | Life Sciences
16.08.2018 | Materials Sciences