Zymoseptoria tritici is a fungal pathogen causing losses in wheat yields. Here, we present new primer sets for species-specific identification of this microorganism in wheat leaf samples using conventional PCR. Primer sets were validated in silico using tools available in genetic databases. Furthermore, in vitro tests were also carried out on 190 common wheat samples with visual symptoms of Septoria tritici blotch (STB) collected in Poland in three growing seasons (2015, 2016, 2017). The designed primer sets showed full hybridization to the available genetic resources deposited in the NCBI GenBank database, and their high specificity and sensitivity were demonstrated on wheat leaf samples and selected fungal strains.

Zymoseptoria tritici is a fungal pathogen causing losses in wheat yields. Here, we present new primer sets for species-specific identification of this microorganism in wheat leaf samples using conventional PCR. Primer sets were validated in silico using tools available in genetic databases. Furthermore, in vitro tests were also carried out on 190 common wheat samples with visual symptoms of Septoria tritici blotch (STB) collected in Poland in three growing seasons (2015, 2016, 2017). The designed primer sets showed full hybridization to the available genetic resources deposited in the NCBI GenBank database, and their high specificity and sensitivity were demonstrated on wheat leaf samples and selected fungal strains.

Zymoseptoria tritici is a fungal pathogen causing losses in wheat yields. Here, we present new primer sets for species-specific identification of this microorganism in wheat leaf samples using conventional PCR. Primer sets were validated in silico using tools available in genetic databases. Furthermore, in vitro tests were also carried out on 190 common wheat samples with visual symptoms of Septoria tritici blotch (STB) collected in Poland in three growing seasons (2015, 2016, 2017). The designed primer sets showed full hybridization to the available genetic resources deposited in the NCBI GenBank database, and their high specificity and sensitivity were demonstrated on wheat leaf samples and selected fungal strains.

Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), a disease of wheat (Triticum aestivum) that results in significant yield loss worldwide. Z. tritici’s life cycle, reproductive system, effective population size, and gene flow put it at high likelihood of developing fungicide resistance. Succinate dehydrogenase inhibitor (SDHI) fungicides (FRAC code 7) were not widely used to control STB in the Willamette Valley until 2016. Field isolates of Z. tritici collected in the Willamette Valley at dates spanning the introduction of SDHI (2015 to 2017) were screened for sensitivity to four SDHI active ingredients: benzovindiflupyr, penthiopyrad, fluxapyroxad, and fluindapyr. Fungicide sensitivity changes were determined by the fungicide concentration at which fungal growth is decreased by 50% (EC50) values. The benzovindiflupyr EC50 values increased significantly, indicating a reduction in sensitivity, following the adoption of SDHI fungicides in Oregon (P < 0.0001). Additionally, significant reduction in cross-sensitivity among SDHI active ingredients was also observed with a moderate and significant relationship between penthiopyrad and benzovindiflupyr (P = 0.0002) and a weak relationship between penthiopyrad and fluxapyroxad (P = 0.0482). No change in cross-sensitivity was observed with fluindapyr, which has not yet been labeled in the region. The results document a decrease in SDHI sensitivity in Z. tritici isolates following the introduction of the active ingredients to the Willamette Valley. The reduction in cross-sensitivity observed between SDHI active ingredients highlights the notion that careful consideration is required to manage fungicide resistance and suggests that within-group rotation is insufficient for resistance management.

Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), a disease of wheat (Triticum aestivum) that results in significant yield loss worldwide. Z. tritici’s life cycle, reproductive system, effective population size, and gene flow put it at high likelihood of developing fungicide resistance. Succinate dehydrogenase inhibitor (SDHI) fungicides (FRAC code 7) were not widely used to control STB in the Willamette Valley until 2016. Field isolates of Z. tritici collected in the Willamette Valley at dates spanning the introduction of SDHI (2015 to 2017) were screened for sensitivity to four SDHI active ingredients: benzovindiflupyr, penthiopyrad, fluxapyroxad, and fluindapyr. Fungicide sensitivity changes were determined by the fungicide concentration at which fungal growth is decreased by 50% (EC50) values. The benzovindiflupyr EC50 values increased significantly, indicating a reduction in sensitivity, following the adoption of SDHI fungicides in Oregon (P < 0.0001). Additionally, significant reduction in cross-sensitivity among SDHI active ingredients was also observed with a moderate and significant relationship between penthiopyrad and benzovindiflupyr (P = 0.0002) and a weak relationship between penthiopyrad and fluxapyroxad (P = 0.0482). No change in cross-sensitivity was observed with fluindapyr, which has not yet been labeled in the region. The results document a decrease in SDHI sensitivity in Z. tritici isolates following the introduction of the active ingredients to the Willamette Valley. The reduction in cross-sensitivity observed between SDHI active ingredients highlights the notion that careful consideration is required to manage fungicide resistance and suggests that within-group rotation is insufficient for resistance management.

Zymoseptoria tritici is the causal agent of Septoria tritici blotch (STB), a disease of wheat (Triticum aestivum) that results in significant yield loss worldwide. Z. tritici’s life cycle, reproductive system, effective population size, and gene flow put it at high likelihood of developing fungicide resistance. Succinate dehydrogenase inhibitor (SDHI) fungicides (FRAC code 7) were not widely used to control STB in the Willamette Valley until 2016. Field isolates of Z. tritici collected in the Willamette Valley at dates spanning the introduction of SDHI (2015 to 2017) were screened for sensitivity to four SDHI active ingredients: benzovindiflupyr, penthiopyrad, fluxapyroxad, and fluindapyr. Fungicide sensitivity changes were determined by the fungicide concentration at which fungal growth is decreased by 50% (EC50) values. The benzovindiflupyr EC50 values increased significantly, indicating a reduction in sensitivity, following the adoption of SDHI fungicides in Oregon (P < 0.0001). Additionally, significant reduction in cross-sensitivity among SDHI active ingredients was also observed with a moderate and significant relationship between penthiopyrad and benzovindiflupyr (P = 0.0002) and a weak relationship between penthiopyrad and fluxapyroxad (P = 0.0482). No change in cross-sensitivity was observed with fluindapyr, which has not yet been labeled in the region. The results document a decrease in SDHI sensitivity in Z. tritici isolates following the introduction of the active ingredients to the Willamette Valley. The reduction in cross-sensitivity observed between SDHI active ingredients highlights the notion that careful consideration is required to manage fungicide resistance and suggests that within-group rotation is insufficient for resistance management.

Septoria tritici blotch (STB), caused by Zymoseptoria tritici, is an important disease of wheat worldwide. This study was performed to investigate the efficacy of Stb genes against 10 isolates of Z. tritici and to elucidate the resistance response pattern of 185 wheat genotypes to STB. The 10 isolates showed different virulence patterns on the Stb differentials. Effectiveness determination showed that most Stb genes (particularly Stb1–Stb9) were ineffective against the 10 isolates, whereas Kavkaz-K4500 (possessing Stb10, Stb12), Arina and Riband (possessing Stb15), and M3 (possessing Stb16 and Stb17) were resistant to all isolates tested. Of the 185 wheat genotypes, 72% were susceptible to all isolates, indicating that these genotypes lacked any effective resistance genes at the seedling stage against the isolates used. The remaining 51 genotypes showed specific resistance to one or more isolates, suggesting that they contain at least one effective resistance gene. Six genotypes were resistant to all isolates, indicating that they may possess broad-spectrum resistance gene(s) or a combination of diverse uncharacterised Stb genes that could be effectively used in breeding programs.

Septoria tritici blotch (STB), caused by Zymoseptoria tritici, is an important disease of wheat worldwide. This study was performed to investigate the efficacy of Stb genes against 10 isolates of Z. tritici and to elucidate the resistance response pattern of 185 wheat genotypes to STB. The 10 isolates showed different virulence patterns on the Stb differentials. Effectiveness determination showed that most Stb genes (particularly Stb1–Stb9) were ineffective against the 10 isolates, whereas Kavkaz-K4500 (possessing Stb10, Stb12), Arina and Riband (possessing Stb15), and M3 (possessing Stb16 and Stb17) were resistant to all isolates tested. Of the 185 wheat genotypes, 72% were susceptible to all isolates, indicating that these genotypes lacked any effective resistance genes at the seedling stage against the isolates used. The remaining 51 genotypes showed specific resistance to one or more isolates, suggesting that they contain at least one effective resistance gene. Six genotypes were resistant to all isolates, indicating that they may possess broad-spectrum resistance gene(s) or a combination of diverse uncharacterised Stb genes that could be effectively used in breeding programs.

Septoria tritici blotch (STB), caused by Zymoseptoria tritici, is an important disease of wheat worldwide. This study was performed to investigate the efficacy of Stb genes against 10 isolates of Z. tritici and to elucidate the resistance response pattern of 185 wheat genotypes to STB. The 10 isolates showed different virulence patterns on the Stb differentials. Effectiveness determination showed that most Stb genes (particularly Stb1–Stb9) were ineffective against the 10 isolates, whereas Kavkaz-K4500 (possessing Stb10, Stb12), Arina and Riband (possessing Stb15), and M3 (possessing Stb16 and Stb17) were resistant to all isolates tested. Of the 185 wheat genotypes, 72% were susceptible to all isolates, indicating that these genotypes lacked any effective resistance genes at the seedling stage against the isolates used. The remaining 51 genotypes showed specific resistance to one or more isolates, suggesting that they contain at least one effective resistance gene. Six genotypes were resistant to all isolates, indicating that they may possess broad-spectrum resistance gene(s) or a combination of diverse uncharacterised Stb genes that could be effectively used in breeding programs.

European Journal of Plant Pathology - Zymoseptoria tritici causes septoria tritici blotch (STB), the predominant fungal disease in wheat in Denmark and Sweden. Disease control is highly reliant on...

Journal of Plant Pathology - Septoria tritici blotch (STB) disease caused by Zymoseptoria tritici is the most predominant disease on durum wheat in Tunisia, while its occurrence on bread wheat is...

Journal of Plant Pathology - Septoria tritici blotch (STB) disease caused by Zymoseptoria tritici is the most predominant disease on durum wheat in Tunisia, while its occurrence on bread wheat is...