Location: Crop Improvement and Protection Research
Title: Evidence for host preference of Macrophomina phaseolina on strawberry Authors
Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 12, 2014
Publication Date: N/A
Interpretive Summary: Macrophomina phaseolina is a new pathogen of strawberry that has become a problem in California with the transition to alternative fumigation practices. This study examines genetic groupings of this pathogen recovered from California and compares them to host range differences. The strawberry isolates appear to be specific to this host and group separately from isolates recovered form other hosts.
Technical Abstract: With the transition from broadcast preplant fumigation to individual bed treatment using alternative fumigants, M. phaseolina has become an emerging disease problem in California strawberry production, causing serious losses in all production districts. Population analysis using SSR markers of 68 isolates recovered from across the state reveals a distinct grouping of strawberry isolates separate from isolates recovered from other crops (primarily watermelon, cantaloupe, alfalfa, thyme; 24 isolates). There were two exceptions to this grouping, one strawberry isolate grouped with isolates recovered from other hosts from the Central Valley (CV), and a cantaloupe isolate from the CV grouped with the strawberry isolates. Thirty of the strawberry isolates were from the same field and exhibited several different genotypes. Pathogenicity tests with a subset of isolates recovered from strawberry that represented each subclade were virulent on this host but did not cause disease on the other host species tested. The CV strawberry isolate exhibited low virulence on strawberry. More detailed analyses of host range and virulence on strawberry are in progress.