|WINSLOW, J - California Polytechnic State University|
|HOLMES, G - California Polytechnic State University|
|IVORS, K - California Polytechnic State University|
Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2017
Publication Date: 12/1/2017
Citation: Winslow, J., Mazzola, M., Holmes, G.J., Ivors, K. 2017. Evaluating host resistance to Macrophomina crown rot in strawberry. Phytopathology. 107(Suppl.5), 74.
Technical Abstract: Macrophomina crown rot, caused by the soilborne fungus Macrophomina phaseolina, is an emerging pathogen in California strawberry production. When established, the pathogen can cause extensive plant decline and mortality. Host resistance will be a critical tool for managing this disease and guiding breeding programs in this post methyl bromide era. In order to evaluate strawberry germplasm for resistance to M. phaseolina, a total of ninety cultivars and elite selections, chosen from both public and private breeding programs, were planted in an artificially inoculated field during the fall of 2016 at the California Polytechnic State University in San Luis Obispo. Crown rot severity and plant mortality were assessed over time in both inoculated and non-inoculated plots. Pathogen colonization of strawberry crown and root tissues of four resistant cultivars (Fronteras, Grenada, Petaluma, and Radiance) and four susceptible cultivars (Albion, Festival, San Andreas, and Monterey) were quantified using a previously described qPCR protocol. The main goals of this research are to correlate host symptom expression with the extent of pathogen colonization in different strawberry tissues, and to determine if resistant germplasm contributes to secondary inoculum production in the field.