Phenotypic and genetic analysis of the Triticum monococcum-Mycosphaerella graminicola interaction

• Published in: The New phytologist 2008-09, Vol.179 (4), p.1121-1132
• Main Authors: Jing, Hai-Chun, Lovell, Darren, Gutteridge, Richard, Jenk, Daniel, Kornyukhin, Dmitry, Mitrofanova, Olga P, Kema, Gert H.J, Hammond-Kosack, Kim E
• Format: Article
• Language: English
• Subjects: aestivum l; anamorph septoria-tritici; Ascomycota - physiology; Ascomycota - ultrastructure; blotch pathogen; compatible and incompatible disease interactions; cultivars; disease resistance; domestication; Fungal infections; Genes, Plant - physiology; Genetic loci; genome; Hexaploidy; identification; Immunity, Innate - genetics; Infections; inheritance; Microbial genetics; Mycosphaerella graminicola; Phenotype; Phenotypes; Plant diseases; Plant Diseases - genetics; Plant Diseases - microbiology; Plant Leaves - genetics; Plant Leaves - microbiology; Plant Leaves - ultrastructure; Polyploidy; Pycnidia; Quantitative Trait Loci; resistance gene mapping; scanning electron microscopy; Septoria tritici; septoria tritici blotch; Spores, Fungal - physiology; Sporulation; TmStb1; Triticum; Triticum - genetics; Triticum - microbiology; Triticum - ultrastructure; Triticum aestivum; Triticum monococcum; Wheat; winter-wheat
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2008.02526.x

Here, the aim was to understand the cellular and genetic basis of the Triticum monococcum-Mycosphaerella graminicola interaction. Testing for 5 yr under UK field conditions revealed that all 24 T. monococcum accessions exposed to a high level of natural inocula were fully resistant to M. graminicola. When the accessions were individually inoculated in the glasshouse using an attached leaf seeding assay and nine previously characterized M. graminicola isolates, fungal sporulation was observed in only three of the 216 interactions examined. Microscopic analyses revealed that M. graminicola infection was arrested at four different stages post-stomatal entry. When the inoculated leaves were detached 30 d post inoculation and incubated at 100% humidity, abundant asexual sporulation occurred within 5 d in a further 61 interactions. An F₂ mapping population generated from a cross between T. monococcum accession MDR002 (susceptible) and MDR043 (resistant) was inoculated with the M. graminicola isolate IPO323. Both resistance and in planta fungal growth were found to be controlled by a single genetic locus designated as TmStb1 which was linked to the microsatellite locus Xbarc174 on chromosome 7Am. Exploitation of T. monococcum may provide new sources of resistance to septoria tritici blotch disease.