Thesis
Carbon source-dependent effects of anaerobic soil disinfestation on the soil metabolone, microbiome and incidence of fusarium wilt in strawberry
Washington State University
Master of Science (MS), Washington State University
12/2019
DOI:
https://doi.org/10.7273/000003990
Handle:
https://hdl.handle.net/2376/124804
Abstract
Fusarium wilt caused by Fusarium oxysporum f. sp. fragariae (Fof) is a major threat to strawberry (Fragaria xananassa Duch.) production in coastal California. Anaerobic soil disinfestation (ASD) is a pre-plant soil treatment that, with the appropriate carbon source, has proven effective in control of specific soil-borne diseases in strawberry (Fragaria xananassa Duch.), such as Verticillium wilt caused by Verticillium dahliae. However, no such combination has consistently controlled Fusarium wilt in strawberry caused by Fusarium oxysporum f. sp. fragariae (Fof). A bioassay was conducted using soils artificially infested with Fof and amended with either rice bran (Oryza sativa L.; 4.9 tons ha-1), ground orchard grass (Dactylis glomerata L.; 10 tons ha-1), or ground wheat grass (Triticum aestivum L. cv. 'Alpowa'; 10 tons ha-1) in combination with ASD, then compared to no-amendment and aerobic controls. The addition of carbon inputs to soil without subsequent ASD treatment amplified disease progression and resulted in a higher density of Fof in the soil and strawberry crowns than those treated with ASD. Strawberry plants grown in soils treated with ASD exhibited a slower rate of disease progression, however no treatment provided sufficient disease control. Disease control induced by ASD has been attributed to the resulting shift in soil microbiome composition, but the relationship between carbon input type and effects on subsequent trajectory of the microbiome and metabolome structure has not been assessed. A comprehensive study of the soil microbiome and metabolome was conducted in attempt to identify mechanisms contributing to soil-borne disease control in response to ASD utilizing different carbon inputs. ASD conducted with a carbon input resulted in an initial increase in Fof population. Subsequent decreases in Fof population coincided with generation of anaerobic conditions, hydrocarbons, sulfur compounds and corresponding increases in populations of Clostridium spp. Carbon inputs created distinct soil community microbiomes and metabolomes when compared to the no amendment controls, but none of the treatments effectively controlled the target pathogen. Optimization of ASD for the management of Fof will require further evaluation of carbon amendments and environmental conditions.
Metrics
6 File views/ downloads
70 Record Views
Details
- Title
- Carbon source-dependent effects of anaerobic soil disinfestation on the soil metabolone, microbiome and incidence of fusarium wilt in strawberry
- Creators
- Emmi Klarer
- Contributors
- Mark Mazzola (Advisor) - Washington State University, Department of Plant Pathology
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Plant Pathology
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900890798301842
- Language
- English
- Resource Type
- Thesis