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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Emerging Pests and Pathogens Research » Research » Publications at this Location » Publication #345438

Research Project: Characterization of Molecular Networks in Diseases Caused by Emerging and Persistent Bacterial Plant Pathogens

Location: Emerging Pests and Pathogens Research

Title: Pectobacterium and Dickeya responsible for potato blackleg disease in New York state in 2016

item MA, XING - Cornell University - New York
item PERRY, KEITH - Cornell University - New York
item Swingle, Bryan
item PERRY, KEITH - Cornell University - New York

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2018
Publication Date: 7/11/2018
Citation: Ma, X., Perry, K., Swingle, B.M., Perry, K. 2018. Pectobacterium and Dickeya responsible for potato blackleg disease in New York state in 2016. Plant Disease. 102(9):1834-1840.

Interpretive Summary: Potato is a major food crop in the United States. There is a new and destructive bacterial disease of potato that has spread to all of the potato growing regions of the United States. More work needs to be done to determine the value of the damage caused by these bacteria. We are working to determine the cause of the disease so that we can identify the source and devise ways to stop the disease. To do this, we analyzed diseased potato plants that were submitted by commercial potato farmers in New York State. We used several tests to identify the bacteria present in the diseased plants and to determine that they were capable of causing the disease. We found that half of the pathogenic bacteria we isolated were Dickeya dianthicola. This is a new pathogen to the United States. We are now working on determining whether all the D. dianthocola bacteria that we and others find are the same or different. Finding a clonal population would be consistent with the presence of an epidemic of this disease in the United States.

Technical Abstract: Potato (Solanum tuberosum) production in the US reached 20 million metric ton and was valued at $3.9 billion in 2015 (USDA-NASS). Recently there have been increasing concerns about a widespread outbreak of a new soft-rot bacterial pathogen in the US commercial potato production system. Several industry and university extension articles suggest new Dickeya and Pectobacterium species are responsible for increased incidence of potato blackleg disease across the United States. During July and August of 2016, we received a total of 43 samples of young potato plants with blackleg disease symptoms from more than 20 commercial potato production farms operating in five counties of New York State. We used a series of molecular and microbiological diagnostic tests to determine whether soft-rot Enterobacteriaceae pathogens were present in the diseased plants. We found bacteria from the genus Dickey and Pectobacterium in 23 plants. Finding Pectobacterium was not surprising as it is considered a persistent low-level problem in New York and in many of the potato growing regions in the United States. However, phylogenetic analysis indicated that the all Dickeya bacteria isolated belong to the species dianthicola. Dickeya dianthicola has not previously been identified in diseased potato plants in New York and this data supports a hypothesis that D. dianthicola is responsible for the recent increase in blackleg disease in potato.