2018 ASHS Annual Conference

Downy mildew, caused by the plant fungal pathogen Peronospora farinosa f. sp. spinaciae (Pfs), is an important disease of spinach, particularly for Spinacia oleracea, the most commonly cultivated spinach species in United States and Europe. To date, 16 races of the downy mildew (DM) pathogen are recognized but new isolates are continuously emerging each year. The ability of new strains of the pathogen to overcome resistance in spinach plants makes the development of spinach varieties with increased levels of resistance to Pfs challenging and essential. Genome wide association mapping offers a promising tool to identify QTLs associated with downy mildew resistance against emerging new races of Pfs. The identified QTLs can be readily used to improve genetic resistance against downy mildew disease in spinach. A total of 481 spinach genotypes are evaluated to identify potential resistant germplasm to be used in spinach breeding programs. The evaluated population will be subjected to genome wide association mapping. As a result of this study, SNP markers for downy mildew resistance will provide breeders with a tool to select resistant plants and lines in spinach against downy mildew resistance.

Downy mildew, caused by the plant fungal pathogen Peronospora farinosa f. sp. spinaciae (Pfs), is an important disease of spinach, particularly for Spinacia oleracea, the most commonly cultivated spinach species in United States and Europe. To date, 16 races of the downy mildew (DM) pathogen are recognized but new isolates are continuously emerging each year. The ability of new strains of the pathogen to overcome resistance in spinach plants makes the development of spinach varieties with increased levels of resistance to Pfs challenging and essential. Genome wide association mapping offers a promising tool to identify QTLs associated with downy mildew resistance against emerging new races of Pfs. The identified QTLs can be readily used to improve genetic resistance against downy mildew disease in spinach. A total of 481 spinach genotypes are evaluated to identify potential resistant germplasm to be used in spinach breeding programs. The evaluated population will be subjected to genome wide association mapping. As a result of this study, SNP markers for downy mildew resistance will provide breeders with a tool to select resistant plants and lines in spinach against downy mildew resistance.