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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #403864
Research Project: Disease Management and Improved Detection Systems for Control of Pathogens of Vegetables and Strawberries

Location: Crop Improvement and Protection Research

Title: Comparative genomics and literature review of Macrophomina phaseolina indicate that a re-interpretation of host range is necessary

Author
item PENNERMAN, KAYLA - Oak Ridge Institute For Science And Education (ORISE)
item DILLA-ERMITA, JADE - University Of California
item Henry, Peter

Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/26/2023
Publication Date: 8/14/2023
Citation: Pennerman, K., Dilla-Ermita, J., Henry, P.M. 2023. Comparative genomics and literature review of Macrophomina phaseolina indicate that a re-interpretation of host range is necessary. American Phytopathological Society Annual Meeting, August 14, 2023, Denver, Colorado.

Interpretive Summary:

Technical Abstract: Macrophomina phaseolina is a broad host range pathogen of many plant species. It regularly ranks among the top ten causes of yield loss in U.S.A. soybean and is among the most destructive soilborne pathogens of strawberry worldwide. This pathogen’s impact is expected to increase, as climate change exacerbates abiotic stresses that play a large role in disease development. However, little is known about the genetic diversity in this species or how this diversity relates to host range, virulence, or geography. Furthermore, we reviewed more than 1,075 peer-reviewed publications about M. phaseolina from between 1905 and 2022 and discovered a pattern of wildly exaggerated claims of this fungus’s host range that are not supported by currently-accessible, primary literature. We sequenced whole genomes from more than 400 isolates of Macrophomina spp. that were collected from almost 100 host plant species in 24 countries. Comparative genomics yielded evidence of recent admixture among these isolates as well as the first evidence of host specialization in M. phaseolina. Specific clades are almost entirely comprised of isolates from either soybean or strawberry, and almost all soybean and strawberry isolates are associated with each of these clades. These results imply a much more nuanced picture of the host range of M. phaseolina, with specialization apparently having occurred on soybean and strawberry, and with ‘generalist’ clades comprising isolates from many different hosts. This work argues for a re-definition of our understanding of host range in M. phaseolina.