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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Research Project #444376

Research Project: Effect of Irrigation Regime and Soil Transmission on the Lettuce Microbiome

Location: Produce Safety and Microbiology Research

Project Number: 2030-42000-052-012-I
Project Type: Interagency Reimbursable Agreement

Start Date: Mar 27, 2023
End Date: Sep 30, 2023

1) Assess the role of the irrigation regime and soil transmission on the lettuce microbiome composition in different plant parts at various growth stages throughout the spring and fall seasons. 2) Investigate the role of plant metabolites in lettuce cultivars shown to have high vs low inhibition of E. coli survival on shredded lettuce under cold storage.

1) Lettuce of a commercial cultivar will be planted in the Chualar experimental field of AgMetrics in Salinas, CA. The field will be managed according to commercial practices and will be split in two main plots with several lettuce beds each, separated by non-sampled buffer beds. The two main plots will be irrigated overhead up to plant thinning, then each plot will be irrigated either overhead or through drip. Samples of soil and lettuce from seed to harvest will be collected and sent to the FDA, Laurel, MD for microbiome analysis by metagenomics. 2) Lettuce cultivars that were identified to be highly inhibitory to STEC on cold-stored lettuce in a past laboratory screen of 31 cultivars, will be analyzed for their metabolome in comparison to cultivars that promoted the greatest survival of the pathogen. Lettuce will be grown at WRRC, shredded and cold-stored, and metabolome samples will be prepared to send to UC Davis for untargeted metabolome profiling.