|GE, T - University Of Maine|
|MARANGONI, N - University Of Maine|
|HAO, J - University Of Maine|
|Larkin, Robert - Bob|
|JOHNSON, S - University Of Maine Cooperative Extension|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/27/2018
Publication Date: 10/1/2018
Citation: Ge, T., Marangoni, N., Hao, J., Larkin, R.P., Johnson, S.B. 2018. Isolation and identification of bacteria causing blackleg and soft rot of potato. Phytopathology. 108: S1.62.
Technical Abstract: Both Dickeya and Pectobacterium spp. are important causal agents of blackleg and soft rot of potato. To understand the outbreak of blackleg in the Northeastern U.S. in 2015, samples were collected from symptomatic plants, dormant tubers, and surface water in 2016 and 2017. Diseased plant samples were primarily from Maine, but also were collected from other Eastern states where Maine seed tubers were planted. Dickeya and Pectobacterium spp. were isolated and purified from the samples on crystal violet pectate agar (CVP). Genomic DNAs were extracted from the samples with FastDNA Kit. Polymerase chain reaction (PCR) was performed using genus-specific primers to detect Dickeya and Pectobacterium spp. The gapA gene was amplified with PCR, and the amplicon was sequenced and analyzed with software MEGA7 and Snapgene Viewer to differentiate among species. In results, Dickeya dianthicola, Pectobacterium parmentieri, and P. carotovorum were identified from potato plant and tuber isolates. In water samples, 43% was either Dickeya or Pectobacterium positive; Dickeya zeae, D. dianthicola, D. dadantii, P. parmentieri, and P. carotovorum were found from water samples. Phylogenetic tree showed that D. dianthicola isolates were in a homogenous group, but it has not been determined whether water was associated with the disease outbreak.