Resistance of wheat (Triticum aestivum) to Septoria tritici blotch (Mycosphaerella graminicola) on leaf segments

Selected winter wheat cultivars, breeding lines; old Czech and Slovak landraces and wild wheat relatives were infected with three isolates (R-116, UH-105, BR-331) of Mycosphaerella graminicola (anamorph Septoria tritici) isolated in the Czech Republic. The cultivar CW9358 was the most susceptible to R-116 and UH-105; the most resistant cultivars were Ordeal and SG-U7029. Estica, CWW93/58 and Verna were the most susceptible cultivars to R-116; the most resistant was SG-U7029. The most susceptible cultivars to UH-105 were CWW93/58 and NSL9257, the most resistant cultivar Samanta. The most susceptible cultivars to BR-331 were Estica and Verna. The most resistant was the advanced line SG-S1990. Of the old Czech and Slovak land races the cultivar Rokycansk Sametka was the most susceptible and the Hanck Blka was the most resistant to all three isolates. Wheat wild relatives T. monococcum, T. dicoccoides and T. araraticum were completely resistant to the isolate R-116. Nearly resistant was Hanck Blka. The cultivars Dobrovick 10 and Pyelka were the most susceptible to this isolate. The cultivars Hanck Blka, Slovensk B, Kostomlatsk Sametka and Dobrovick 10 were completely resistant to UH-105. Nearly resistant was esk Pesvka. The most susceptible was Pyelka. The cultivars Hanck Blka, Slovensk B, Pyelka and Dobrovick 10 were completely resistant to BR-331. Nearly resistant were wheat wild relatives T. araraticum and T. boeticum. The most susceptible was Rokycansk Sametka and T. dicoccoides. The cultivars Hanck Blka, Slovensk B, Dobrovick 10 were completely resistant to UH-105 and BR-331. Clearly, different isolates of Mycosphaerella graminicola differ in virulence for individual wheat cultivars.