Behavior of Spanish durum wheat genotypes against Zymoseptoria tritici: resistance and susceptibility

Aim of study: Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici, is one of the most important wheat diseases worldwide, affecting both bread and durum wheat. The lack of knowledge about the interaction of durum wheat with Z. tritici, together with limited resources of resistant durum wheat material, have both led to a rising threat for durum wheat cultivation, particularly in the Mediterranean Basin. In Spain, STB has increased its incidence in the last few years, leading to higher costs of fungicide applications to control the disease. Therefore, identification of new sources of resistance through wheat breeding stands out as an efficient method of facing STB.Area of study: The experimental study was conducted in growth chambers at the IFAPA facilities in Córdoba (Spain).Material and methods: The percentage of necrotic leaf area, the disease severity, and the pycnidium development through image analysis were evaluated from 48 durum wheat Spanish accessions (breeding lines and commercial cultivars) in growth chambers against an isolate of Z. tritici from Córdoba.Main results: Two breeding lines and six commercial cultivars showed resistant responses by limiting STB development through the leaf or its reproduction ability, while the other 40 accessions presented a susceptible response.Research highlights: Provided these resources of resistance in Spanish durum wheat genotypes, future breeding programs could be developed, incorporating both agronomic traits and resistance to STB