Scientists Unveil Genetic Map to Wheat 'Cancer'

Chinese scientists have created the world's first genetic map for wheat resistance to yellow rust, a destructive fungal disease. Published in Nature Genetics, this breakthrough was a collaborative effort between Northwest Agriculture and Forestry University (NWAFU) and the Chinese Academy of Sciences' Institute of Genetics and Developmental Biology. The map provides plant breeders with a crucial tool to develop more durable wheat varieties that are resistant to the disease.

Yellow rust, often called "wheat cancer," is caused by Puccinia striiformis f. sp. tritici (Pst). This rapidly mutating disease generates a new dominant pathotype approximately every five years and is responsible for an estimated 10% of global wheat yield loss annually. The research team, led by Kang Zhensheng of NWAFU, spent five years comprehensively analyzing 2,191 wheat accessions globally and over 47,000 yellow rust response records. Their work systematically reveals the co-evolutionary dynamics between wheat resistance genes and pathogen races over the past century.

They identified 431 yellow rust resistance loci and constructed a genome-wide map of these genes. From 559 candidate genes, they successfully cloned three novel resistance genes, including Yr5x, a new allele showing resistance to multiple Pst races; Yr6/Pm5, which provides dual resistance to both yellow rust and powdery mildew; and YrKB (TaEDR2-B), which confers broad-spectrum rust resistance without negatively impacting yield. These elite haplotypes that combine disease resistance with strong agricultural performance represent a significant advancement in breeding resistant wheat cultivars, which is crucial for managing this devastating disease.

For more details, read this article or download the paper in Nature Genetics.