Magnaporthiopsis poae infection symptoms on Kentucky bluegrass (Poa pratensis L.)
Image Credit: Lee Miller, University of Missouri, Bugwood.org.

The genome of Magnaporthiopsis poae was sequenced by the Broad Institute. In order to allow comparative analyses with other fungi, a copy of this genome was imported into MycoCosm.

Magnaporthiopsis poae (Kentucky bluegrass fungus), synonym Magnaporthe poae, causes “summer patch” of Poa species, creeping bentgrass, and fine-leaved fescues.  It is considered one of the most important diseases on turfgrass in North America. The pathogen was first identified in 1984 and can decimate lawns and athletic fields.

Traditionally, M. poae is associated with Kentucky bluegrass fairways, athletic fields and home lawns. Magnaporthe is a significant problem on annual bluegrass putting greens in the Northeast U.S as well.  Recently, it has been reported as a pathogen of creeping bentgrass (Agrostis stolonifera) in North Carolina in 2005.  M. poae’s geographic distribution ranges from the New England states to as far south as North Carolina and as far west as Nebraska.  

M. poae produces sexual structures (perithecia, asci and ascospores) that clearly place it with Magnaporthe. However, unlike other Magnaporthe species such as M. salvinii, M. grisea and M. oryzae, which have Pyricularia anamorphs (forms that produce asexual spores) bearing spores sympodially on conidiophores, the M. poae anamorph has Phialophora like spores borne on phialides, in much the same manner as Gaeumannomyces. As such, M. poae, along with M. rhizophila, seems to represent a phylogenetic bridge between the Magnaporthe: Pyricularia and Gaeumannomyces:Phialophora groups.