Mapping of quantitative trait loci (QTL) for resistance against Zymoseptoria tritici in the winter spelt wheat accession HTRI1410 (Triticum aestivum subsp. spelta)

Zymoseptoria tritici, the causal agent of Septoria tritici blotch (STB) causes yield losses in wheat of up to 40%, globally. Growing of resistant cultivars is the most cost effective and environmentally friendly way to avoid these losses. Therefore, there is a need to identify new resistances in gene bank accessions and to get information on the genetics of resistance followed by the development of molecular markers for the efficient deployment of these resistances in wheat breeding. In extensive screening programs for resistance, the spelt wheat gene bank accession HTRI1410 turned out to be resistant to Zymoseptoria tritici in field conditions. In order to get information on the genetics of the STB resistance in HTRI1410, a DH population consisting of 135 lines derived from crosses of HTRI1410 to three susceptible cultivars was developed. Significant genotypic differences and a quantitative variation for the reaction to Zymoseptoria tritici was observed. Based on these phenotypic data and a genetic map comprising 714 90K iSelect derived SNP markers four quantitative trait loci on chromosomes 5A, 4B and 7B, explaining 8.5–17.5% of the phenotypic variance were identified.