Abstract

Members of the Ralstonia solanacearum species complex (RSSC), causing potato bacterial wilt or brown rot, are highly contagious and there are no known cultivars with durable resistance to the pathogen. This study hypothesized (a) that crops intercropped or rotated with potato, plants in the same family, and plants grown in the neighbouring fields can host the pathogen and they can be potential sources of primary inoculum, and (b) that potato cultivars currently multiplied by the public tissue culture laboratory in Rwanda are less susceptible to the pathogen. Fourteen plant species and potato, and nine potato cultivars were tested for susceptibility to an RSSC phylotype II strain under greenhouse conditions. The bacteria induced symptoms on potato, tomato, tree tomato, sweet pepper, and eggplant only. Among the plant species with symptoms, potato, tomato, and tree tomato wilted completely. There was a significant difference in days to symptom expression and to complete wilting (p < .0001). While all tested potato cultivars were found to be susceptible, the number of days to first symptom expression, days to complete wilting, area under the disease progress curve (AUDPC), and the number and weight of harvested tubers varied considerably. Cultivars Cruza, Kinigi, and CIP-58 were less susceptible whereas the cultivars Gikungu, Kirundo, and Victoria were highly susceptible. There is a strong need to search for other sources of resistance. The results indicate that some plant species that might serve as a reservoir of the bacterium should be avoided in the vicinity of potato crops.

Keywords

potato cultivars; Ralstonia solanacearum; Solanum tuberosum; survival analysis; susceptibility

Published in

Plant Pathology
2020, Volume: 69, number: 3, pages: 559-568
Publisher: WILEY

SLU Authors

• Uwamahoro, Florence

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    
  • University of Rwanda

• Berlin, Anna

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

• Bylund, Helena

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Yuen, Jonathan

  • Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

End hunger, achieve food security and improved nutrition and promote sustainable agriculture


UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1111/ppa.13140

Permanent link to this page (URI)

https://res.slu.se/id/publ/103950