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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 #378117
Research Project: Characterization of Molecular Networks in Diseases Caused by Emerging and Persistent Bacterial Plant Pathogens

Location: Emerging Pests and Pathogens Research

Title: First Report of Dickeya dianthicola causing blackleg on New Guinea Impatiens (Impatiens hawkeri) in New York State, USA

Author
item LIU, YINGYU - Cornell University
item VASIU, SAKSHI - Cornell University
item DAUGHTREY, MARGERY - Cornell University
item Filiatrault, Melanie

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2020
Publication Date: 11/17/2020
Citation: Liu, Y., Vasiu, S., Daughtrey, M., Filiatrault, M.J. 2020. First Report of Dickeya dianthicola causing blackleg on New Guinea Impatiens (Impatiens hawkeri) in New York State, USA. Plant Disease. https://doi.org/10.1094/PDIS-09-20-2020-PDN.
DOI: https://doi.org/10.1094/PDIS-09-20-2020-PDN

Interpretive Summary: New Guinea Impatiens (NGI) are an ornamental crop with a $40-million wholesale market in the United States. In March 2019, NGI in a New York greenhouse showed wilting, black stem streaks and vascular discoloration, with a 20% disease incidence. We identified the bacteria, Dickeya dianthicola, as a causative agent of blackleg on New Guinea Impatiens. This is the first report of Dickeya dianthicola causing disease on New Guinea Impatiens. These findings are helping to provide insights about bacterial pathogens that threaten ornamental and vegetable crops.

Technical Abstract: New Guinea impatiens (NGI), Impatiens hawkeri, is an important horticultural crop because of its $40-million wholesale market in the United States and its natural resistance to Impatiens downy mildew. In March 2019, NGI in a New York greenhouse showed wilting, black stem streaks and vascular discoloration, with a 20% disease incidence. Bacterial colonies were isolated and an isolate was named as 69-19. Using 16S rDNA sequencing and genus-specific PCR, we identified the bacteria as Dickeya dianthicola. The pathogenicity of D. dianthicola 67-19 was confirmed on NGI cultivars Petticoat White and Tamarinda White and the causative agent was re-isolated and verified. To our knowledge, this is the first report of blackleg of NGI caused by D. dianthicola in the United States. Bacterial diseases caused by D. dianthicola pose significant threats to the ornamental and potato industries. Our results will help guide future research on finding treatments and strategies to manage diseases caused by D. dianthicola.