|Anderson, Safyre - University Of Illinois|
|Soman, Chinmay - University Of Illinois|
|Bekal, Sadia - University Of Illinois|
|Lambert, Kris - University Of Illinois|
|Bhalerao, Kaustubh - University Of Illinois|
Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2017
Publication Date: 9/3/2018
Citation: Anderson, S., Soman, C., Bekal, S., Domier, L.L., Lambert, K., Bhalerao, K. 2018. An agent-based metapopulation model simulating virus-based biocontrol of Heterodera glycines. Journal of Nematology. 50:79-90.
Interpretive Summary: The soybean cyst nematode (SCN), is a damaging pest of soybean that causes significant yield losses each year. Natural resistance to SCN has been identified in soybean germplasm, but the overuse of one source of SCN resistance has caused an increase in nematodes that can reproduce on resistant soybean plants. Recently discovered SCN-infecting viruses are potential biological control agents for these damaging pests. This study developed a computer model to simulate the interactions between SCN and nematode-infecting viruses and explore the properties of viruses that would make useful biocontrol agents. The computer model highlighted that virus-based biocontrol worked best at very high infection rates and when the nematode viruses were of moderate virulence. If the viruses killed nematodes too quickly, they did not persist with in the nematode populations. If virulence was too low, the viruses were not effective biological control agents. The predictions of the computer model provided information that will be useful in selecting viruses for biological control of SCN, which will be useful for scientist investigating the use of viruses for control of plant pests.
Technical Abstract: With recently discovered soybean cyst nematode (SCN) viruses, biological control of the nematodes is a theoretical possibility. This study explores the question of what kinds of viruses would make useful biocontrol agents, taking into account evolutionary and population dynamics. An agent-based model, the Soybean Cyst Nematode Simulation (SCNSim), was developed to simulate within-host virulence evolution in a virus-nematode-soybean ecosystem. SCNSim was used to analyze nematode suppression under a range of viral mutation rates, initial virulences, and release strategies. The simulation highlighted that virus-based biocontrol worked best when the nematodes were inundated with the viruses. Under lower infection prevalence, the viral burden thinned out rapidly due to the limited mobility and high reproductive rate of the SCN. In accordance with the generally accepted trade-off theory, SCNSim indicated an optimal virulence for the greatest nematode damage. Higher virulence resulted in shorter lifetime transmission, whereas viruses with lower virulence values evolved towards avirulence. SCNSim also indicated that a greater mutation rate reinforced the virulence pathotype, suggesting the presence of a virulence threshold necessary for biocontrol in this model system.