Molecular Plant Pathology – Pathogen Profiles

Mycosphaerella graminicola: latent infection, crop devastation and genomics

Claire-Louise Palmer1 and Wendy Skinner2

School of Biological Sciences, University of Bristol, Woodland Road, Clifton, Bristol, BS8 1UG. UK.
IACR Long Ashton Research Station, Department of Agricultural Sciences, University of Bristol, Long Ashton, Bristol BS41 9AF, UK

Summary:Mycosphaerella graminicola is an important pathogen of wheat, causing septoria leaf blotch disease. This review summarizes the current knowledge on disease development and control of the fungus, and discusses how molecular tools and genomics are being employed to uncover the genetic basis of pathogenicity.
Taxonomy:Mycosphaerella graminicola (Fuckel) J. Schröt. in Cohn (anamorph: Septoria triticiRoberge in Desmaz.). Kingdom Fungi, Phylum Ascomycota, Class Loculoascomycetes (filamentous ascomycetes), Order Dothideales, Genus Mycosphaerella, Species graminicola.
Host range:Bread and durum wheat (Triticum aestivum L. and T. turgidum ssp. durum L.) Disease symptoms: Initiating with the appearance of chlorotic flecks on leaves that develop into irregular sunken necrotic lesions peppered with tiny black spots (pycnidia). In addition to the necrotic tissue, the disease results in early leaf tissue senescence and therefore reduced photosynthetic capacity.
Useful web sites:
Symptoms and stages of infection by M. graminicola. (a) Septoria leaf blotch symptoms on a mature wheat leaf (x3). Small black dots are asexual pycnidia. Photo courtesy of T. Hunter and D.J. Royle, IACR Long Ashton Research Station. (b) Penetration of a stomatum from wheat cv. Riband by M. graminicola isolate L951 (x380). Fungal tissue stained with Coomassie Brilliant Blue R250.