Association Mapping of Septoria Speckled Leaf Blotch Resistance in U.S. Barley Breeding Germplasm

摘要

Septoria speckled leaf blotch (SSLB) is a sporadic but important disease of barley (Hordeum vulgare) in the Upper Midwest region of the United States and Prairie Provinces of Canada that is caused primarily by Septoria passerinii. Most of the widely grown cultivars in the region are susceptible to the disease. To identify and map SSLB resistance loci in U.S. barley breeding germplasm, we employed an association mapping approach using 3,840 breeding lines and cultivars and nearly 3,000 singlenucleotide polymorphism markers previously mapped to the seven barleychromosomes. SSLB infection responses (IRs) were assayed on seedling plants in the greenhouse using a 0-to-5 scale. From the analysis of four yearly panels consisting of 960 lines each, four quantitative trait loci (QTL) for SSLB resistance were identifi