2012 Annual Report 1a.Objectives (from AD-416): Identify spinach germplasm with resistance to Verticillium wilt disease. 1b.Approach (from AD-416): Screen spinach germplasm collections for source of resistance against Verticillium wilt under inoculated conditions. 3.Progress Report: This project contributes directly to the objective 3 of the in-house project, genetic improvement of spinach. This report documents research conducted under a Reimbursable Agreement between ARS and the University of California (Davis). Although Verticillium wilt has not been a problem for spinach production in California due to the late appearance of disease symptoms, spinach seeds may bring large amount of pathogen inoculums into fields, which pose a threat to other rotational crops in Salinas Valley such as lettuce and strawberry. No spinach cultivar resistant to Verticillium wilt is available on the market at present. In collaboration with University of California-Davis Lab, we retested the 23 putative resistant accessions of the USDA spinach germplasm collection that were identified in preliminary screening experiments from 2009 to 2011, along with eight susceptible and nine cultivar controls, to confirm their resistance to Verticillium dahliae Race 2 and test their resistance to Race 1 in inoculated tests in greenhouse with nine replications.