Wheat is a primary tillage crop in Ireland and remains the most important cereal crop within the EU. Annually huge yield losses were caused by Zymoseptoria tritici, the causal agent of septoria tritici blotch (STB) disease. Under favourable condition, STB can cause up to 50% yield losses. Farmers are heavily reliant on multiple applications of fungicides throughout the cropping season, where control of STB accounting for more than 70% of annual fungicide usage in Europe, the use of which costs the sector over €1bn per annum. Furthermore, emerging resistance to fungicides and ambitions to reduce pesticide usage in Europe requires that greater emphasis is placed on identifying novel sources of resistance to STB. Identifying sources of resistance can be accelerated using marker-assisted recurrent selection strategies and/or genome-wide selection (genomic selection, GS). Experimental wheat populations such as the multi-parent advanced generation intercross (MAGIC) are a powerful resource to dissect the genetic control of agriculturally important traits. The overall goal of this action was to harness novel sources of resistance to STB that may help reduce dependence on fungicides. . In the present study, the NIAB Diverse MAGIC (NDM) population, comprising of more than 500 recombinant inbred lines (RILs) derived from sixteen founder varieties released between 1935-2004 was investigated for STB resistance under high disease pressure environments. Genomic regions associated with resistance were identified and the linked genetic markers may support rapid selection of favorable alleles for the breeding of new wheat cultivars with improved STB resistance.
