Location: Crop Improvement and Protection ResearchTitle: Bulk soil communities of Fusarium spp. are resilient to changes induced by crop and tillage practices
|EPSTEIN, LYNN - University Of California|
|GORDON, THOMAS - University Of California|
|LEVEAU, JOHAN - University Of California|
Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/27/2021
Publication Date: 8/2/2021
Citation: Henry, P.M., Koehler, S., Epstein, L., Gordon, T.R., Leveau, J.H. 2021. Bulk soil communities of Fusarium spp. are resilient to changes induced by crop and tillage practices. American Phytopathological Society Annual Meeting, August 2-6, 2021 (virtual).
Technical Abstract: The fungal genus Fusarium contains plant pathogenic, beneficial, and commensal strains. Past work suggests that non-pathogenic Fusarium strains can contribute to disease-suppression in soil by competition or induced plant resistance. Identifying factors that influence the abundance of non-pathogenic strains could lead to strategies that enhance plant-beneficial interactions and deter pathogen invasion. We developed an EF-1a amplicon-sequencing method with sub-species resolution for Fusarium community analysis. This method reconstructed Fusarium EF-1a sequences with 100% accuracy and performed close to expectations. Using this method, we observed that non-pathogenic strains of F. oxysporum did not colonize different crops at uniform rates; some strains had asymptomatic host preferences. Whereas healthy plant roots were colonized somewhat evenly by different strains, the strawberry pathogen F. oxysporum f. sp. fragariae (Fof) typically accounted for >90% of sequences in susceptible strawberry roots. Bulk soil communities of Fusarium were remarkably stable regardless of crop history and tillage practices. Although the density of Fof in bulk soil (measured in CFUs/g) was higher after strawberry cultivation than fallow, the relative abundance of Fof (measured by EF-1a amplicon sequencing) was not significantly different. In another cropping system, 18-years of conservation tillage and cover cropping did not alter bulk soil Fusarium communities. We will discuss the implications of these results for the establishment of pathogenic strains in new fields.