Location: Emerging Pests and Pathogens Research
Project Number: 8062-21000-048-002-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2017
End Date: Aug 31, 2022
A recent outbreak of an aggressive soft rot bacterium (Dickeya dianthicola) in U.S. potatoes affects an industry that already struggles to control endemic bacterial pathogens. In 2015, D. dianthicola was reported for the first time in U.S. potatoes and it caused millions of dollars in losses in at least 10 potato-producing states and seriously impacted trade in seed potatoes. Dickeya spread rapidly to additional states in 2016 and, as of 2017, is still being found in a high percentage of seed lots in some states. Dickeya may have become endemic and it will likely be a long-term and devastating threat to the U.S. potato industry. Without an intensive national effort, this outbreak will continue to grow in impact. Because of the dearth of knowledge about its biology and management, the Dickeya outbreak has created an urgent need for research and engagement with affected producers and the potato industry. Industry stakeholders contributed to project development and goals from the beginning of this outbreak in the summer of 2015, and they participated in all aspects of proposal development. An advisory panel is assembled to address the SCRI goal of developing a strategy that can be implemented for this specialty crop. Because Dickeya and Pectobacterium cause nearly identical symptoms and often occur together, so our project must address both pathogens. Our project goals are to provide the potato industry with: (1) improved pathogen detection tools for Dickeya and the closely related pathogen Pectobacterium, (2) information required to develop resistant or tolerant potato varieties, and (3) epidemiological information and economic analysis tools to aid growers in disease management decisions. We have also implemented and will further develop a national extension effort to educate seed and commercial potato growers about management of blackleg and soft rot. Together, these outputs will significantly improve management of potato bacterial diseases. Our project addresses SCRI goals, including: “efforts to identify and address threats from diseases; new innovations and technology; efforts to improve production efficiency, handling and processing, productivity, and profitability: and research in other methods to improve disease management.” ARS will participate in the following objectives: Objective 1B. We will obtain genome sequences of D. dianthicola strains isolated in the US and will test direct genome sequencing technologies for pathogen identification from field samples. Objective 2B We will use RNAseq to map and characterize Dickeya and Pectobacterium resistance genes in Solanum chacoense.
We will use RNAseq to map and characterize Dickeya and Pectobacterium resistance genes in Solanum chacoense. Markers developed from this work will be provided to potato breeding programs.