|GARCIA, JORGE - California State University|
|LARA, CELESTE - California State University|
|SCHRAMM, TARLEE - University Of California|
|HUTMACHER, ROBERT - University Of California|
|NICHOLS, ROBERT - Cotton, Inc|
|ELLIS, MARGARET - California State University|
Submitted to: APS Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/14/2020
Publication Date: 8/3/2020
Citation: Garcia, J., Lara, C., Schramm, T., Hutmacher, R.B., Ulloa, M., Nichols, R., Ellis, M.L. 2020. Baiting techniques used for the isolation of the Fusarium wilt pathogen (Fusarium oxysporum f. sp. vasinfectum) of cotton from field soil. APS Annual Meeting - Plant Health Conference. Denver, CO, USA. August 10-14, 2020. 17388.
Technical Abstract: In California, Fursarium oxysporum f. sp. vasinfectum (FOV) race 4 is an important wilt and seedling pathogen of cotton causing wilt and plant death. Since FOV race 4 was first officially reported in the San Joaquin Valley of California in 2003, many confirmed infested fields have been transitioned into permanent tree crop production such as almond and pistachio. The goal of this research was to develop methods for the isolation of FOV race 4 from soil collected from abandoned or tree crop production, and current cotton field locations. Two methods were tested for the isolation of FOV race 4. The first method consisted of plating a dilution of field soil ratio on a selective Komada medium. Fungal growth resembling Fusarium was then transferred to Potato Dextrose Agar for morphological identification. For the second method, a moderately susceptible Pima cultivar was used as bait and planted directly into the collected field soil. Symptomatic plant tissue was then isolated onto Nash-Snyder medium for the isolation of Fusarium. For both methods, Fusarium isolates were tested using previously reported FOV race 4 specific primers. Current results from both methods were able to isolate FOV race 4 from collected field soil in current cotton production fields. Future work will include using these methods to see if we can bait FOV race 4 from the soil collected in the abandoned or tree production locations. If successful, the FOV race 4 from the old and current production soils will be compared in future genetic studies to look for possible evolutionary changes in the fungus in the long absence or presence of a susceptible plant host.