1a.Objectives (from AD-416)
To screen public spinach germplasm for new sources of resistance to downy mildew race 10.
1b.Approach (from AD-416)
The entire USDA spinach germplasm collection will be screened for downy mildew resistance in inoculated greenhouse tests. Documents Trust with California Leafy Greens Research Board. Log 37163.
Downy mildew caused by Peronospora farinose f. sp. Spinaciae is the most important disease for California spinach growers. Along with the rapid increase of spinach consumption and production in recent years, many new downy mildew races have emerged, including the new Races 10, 11, and 12. Genetic resistance is an important component in the management of the disease. We increased several pathogen isolates and determined their race on differential hosts. Screening of 135 more USDA spinach germplasm accessions plus nine commercial cultivars for resistance to Race 10 was completed. This project contributes directly to the Objective 3 of the in-house project.