- Agronomic: potatoes
- Crop Production: cropping systems, crop rotation
- Pest Management: cultural control, integrated pest management
Management of soilborne pathogens with a wide host range and long-term survival structures is extremely challenging. This is the case for Verticillium wilt, a vascular disease that affects 400 different crops, caused by the fungus Verticillium dahliae. Soil fumigants are the most effective management tool but are of limited use in the Northeastern U.S. due to application restrictions. Despite mixed results, crop rotations are most commonly implemented to manage Verticillium wilt of potato to minimize soil inoculum build-up. It is crucial to select rotational crops that are non-hosts of the pathogen. Studies in potato agroecosystems reported V. dahliae growing asymptomatically in weeds and rotational crops as an endophyte forming inoculum on the host. The long-term goal of this research is to improve crop rotations for disease management based on the interactions between the pathogen and plant species, so that new sustainable practices based on ad hoc rotations can be designed. The objective of this project is to understand the VCG-specificity of V. dahliae interactions with asymptomatic rotational crops in potato fields. We will develop VCG-specific PCR-based markers for detection and quantification of the VCGs prevalent in potato agroecosystems. With this tool we will identify which crop species used in rotation with potato are asymptomatically infected with V. dahliae and which pathogen VCGs infect them. Understanding the specificity of those interactions will allow growers to select rotational and cover crops that are non-hosts of the pathogen or at least not for isolates of aggressive VCGs.
Project objectives from proposal:
In this project, we will address the following hypothesis that is based on preliminary research conducted by our group and existing peer-reviewed literature: In this project, we will address the following hypothesis that is based on preliminary research conducted by our group and existing peer-reviewed literature: Lineages of V. dahliae as characterized by their VCG infect asymptomatic rotational crops and weeds in potato fields. These interactions allow the fungus to complete its life cycle, produce inoculum and shift the genetic diversity of V. dahliae populations present in the soil. The VCG diversity maintained by the asymptomatic hosts harbors potential to dictate the severity and incidence of the epidemic in the subsequent potato crops.
The main objectives of this project are to:
1. Develop VCG-specific PCR-based markers for V. dahliae VCGs 2A, 2B, 4A and 4B to be used for detection in environmental samples such as plant material and soil.
2. Identify which crop species used in rotation with potato are asymptomatically infected with V. dahliae and more specifically, which pathogen VCGs infect them.