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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Research Project #446017

Research Project: Effect of Irrigation Regimes on the Romaine Lettuce and Soil Microbiomes, and Their Transmission, Throughout the Growth Season

Location: Produce Safety and Microbiology Research

Project Number: 2030-42000-052-014-I
Project Type: Interagency Reimbursable Agreement

Start Date: Mar 26, 2024
End Date: Sep 30, 2024

The objective of this study is to characterize 1) the effect of irrigation regimes on the microbiome structure of both soil and lettuce leaves, and to assess the contribution of the soil microbiome to the leaf microbiome in different parts of the lettuce head under these regimes and at different times of the growth season; and 2) lettuce genotypes and phenotypes inhibitory to pathogenic E. coli.

The agency (USDA-ARS) will set up the field plots at Ag Metrics Group in Chualar, near Salinas, and collect all samples to send to the cooperator for microbiome characterization. The cooperator will extract DNA, sequence, and determine microbiome composition through metagenomics. Comparative analysis across treatments and time points will be done will various bioinformatics and statistic software. The agency (USDA-ARS) will also obtain field soil from Salinas to send to the cooperator to set up laboratory experiments with lettuce and STEC under environmental conditions that mimic those in the field. USDA-ARS will collaborate on site at the cooperator's laboratory to set up experiments about STEC survival on lettuce under different irrigation regimes. USDA-ARS will grow in a small portion of the same field at Ag Metrics, lettuce cultivars of interest to microbial safety and to be characterized in USDA-ARS laboratory.