Development of stem-base pathogens on different cultivars of winter wheat determined by quantitative PCR

• Published in: European journal of plant pathology 2002-02, Vol.108 (2), p.163-177
• Main Authors: NICHOLSON, P, TURNER, A. S, EDWARDS, S. G, BATEMAN, G. L, MORGAN, L. W, PARRY, D. W, MARSHALL, J, NUTTALL, M
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Cultivars; Deoxyribonucleic acid; DNA; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fungicides; Generalities. Techniques; Genetics and breeding of economic plants; Pathogens; Pest resistance; Phytopathology. Animal pests. Plant and forest protection; Plant pathogens; Tapesia acuformis; Tapesia yallundae; Triticum aestivum; Varietal selection. Specialized plant breeding, plant breeding aims; Winter wheat
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1023/A:1015087311702

The progress of development of stem-base pathogens in crops of second winter wheat was plotted in nine experiments in three years. The amount of each pathogen present was determined by quantitative PCR. Where Tapesia yallundae was present in quantifiable amounts, it usually developed earlier than the other eyespot pathogen, T. acuformis. Both species were usually present in greater amounts on cultivars which are more susceptible to eyespot. The sharp eyespot pathogen, Rhizoctonia cerealis, developed more erratically than either of the Tapesia spp. and there were no consistent effects on different cultivars. Fusarium spp., the cause of brown foot rot, were rarely present in quantifiable amounts, but Microdochium nivale was usually present as one or both of the varieties nivale and majus. Late-season (after anthesis) decreases in M. nivale suggest that any brown foot rot symptoms attributable to this fungus would have fully developed earlier. Cultivar differences in amounts of M. nivale were most clear in stems during internode extension and when relatively large amounts of DNA were present. Such differences approximately reflected eyespot susceptibility, cv. Soissons containing most and cv. Lynx containing least DNA. The results emphasise the difficulty in relating diagnoses, by quantitative PCR or other means, at early growth stages when decisions to apply fungicides against stem-base disease are made, to later disease severity.[PUBLICATION ABSTRACT]