Contributions of disease resistance and escape to the control of septoria tritici blotch of wheat

• Published in: Plant pathology Vol. 58; no. 5; pp. 910 - 922
• Main Authors: Arraiano, L.S, Balaam, N, Fenwick, P.M, Chapman, C, Feuerhelm, D, Howell, P, Smith, S.J, Widdowson, J.P, Brown, J.K.M
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.10.2009; Blackwell Publishing Ltd; Blackwell
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; breeding; breeding lines; cultivars; disease escape; disease resistance; England; field experimentation; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; genes; heading; isolate-specific resistance; leaf blotch; leaves; Mycosphaerella graminicola; Phytopathology. Animal pests. Plant and forest protection; Septoria tritici; septoria tritici blotch; Stb6; Triticum aestivum; wheat; England; Monocotyledones; Vegetals; Plant pathology; Plant pathogen; Disease; Mycospbaerella gramivzicola; isolate-specific resistance; septoria tritici blotch; Cereal crop; Fungi; Disease resistance; disease escape; Stb6; Sensitivity resistance; Gramineae; Angiospermae; Isolate; Spermatophyta; Septoria tritici; Fungi Imperfecti; C3-Type; Triticum aestivum; Specific resistance
• ISSN: 0032-0862; 1365-3059
• DOI: 10.1111/j.1365-3059.2009.02118.x

The contributions of disease escape and disease resistance to the responses of wheat to septoria tritici leaf blotch (STB) were analysed in a set of 226 lines, including modern cultivars, breeding lines and their progenitors dating back to the origin of scientific wheat breeding. Field trials were located in the important wheat-growing region of eastern England and were subject to natural infection by Mycosphaerella graminicola. STB scores were related to disease-escape traits, notably height, leaf spacing, leaf morphology and heading date, and to the presence of known Stb resistance genes and isolate-specific resistances. The Stb6 resistance gene was associated with a reduction of 19% in the level of STB in the complete set of 226 lines and with a 33% reduction in a subset of 139 lines of semidwarf stature. Greater plant height was strongly associated with reduced STB in the full set of lines, but only weakly in the semidwarf lines. Shorter leaf length was also associated with reduced STB, but, in contrast to earlier reports, lines with more prostrate leaves had more STB on average, probably because they tended to have longer leaves. Several lines, notably cvs Pastiche and Exsept, had low mean levels of STB which could not be explained by either escape traits or specific resistance genes, implying that they have unknown genes for partial resistance to STB.