Profile Created by James
P . Kerns
As a requirement for PP 728, Spring 05
Department of Plant Pathology
|Summer patch of Kentucky bluegrass caused by Magnaporthe poae.||Summer patch of a creeping bentgrass putting green.|
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
M. poae is
M. poae is readily isolated from 3-5 mm segments of roots or crowns of infected plants. The infected root and crowns are dipped in a 1% AgNO3 solution for 30-60 seconds followed by a 5-10 second wash in 5% NaCl solution. After surface-disinfested segments are rinsed in sterile distilled water and blotted dry they can be plated on Gaeumannomyces-selective media or ½ strength PDA amended with 50 mg /L streptomycin sulfate (see Lanschoot 2001). M. poae is not readily isolated from soil.
M. poae is a heterothallic Ascomycete species and perithecia are rarely observed in nature. In culture, perithecia are black, globose, and have long cylindrical necks. The asci inside the perithecia are eight-spored, straight to slightly curved, and have a refractive ring at the apex. The ascospores at maturity have three septations and the end cells are lighter than the center cells. M. poae produce runner hyphae on host stems that are brown and infection hyphae can originate from these runner hyphae. Hyphopodia are dark brown, slightly lobed, and globose, and are typically found on diseased tissues. Mycelium in culture is hyaline, gray or olive-brown, with thick, dark strands of mycelia radiating from the center of the colony.
Perithecia of M. poae on creeping bentgrass Hyphopodia of M. poae.
In higher cuts of turf (>1”), gray-green, wilting plants appear in small non-delineated patches. These patches may progress into circular or irregular-shaped patches up to 30 cm in diameter. White-banded lesions may be apparent on the leaf blades as well. On putting green turf, plants turn yellow in small circular patches, which can increase from 5 cm to 30 cm in diameter.
Symptoms of summer patch on Kentucky bluegrass.
Crown rot of creeping bentgrass associated with M. poae infection.
Ecology and Life Cycle:
Links to other sites:
APS Plant Disease
Note- First Report of Magnaporthe poae
on Creeping Bentgrass in NC
Landschoot, P.J., A.B. Gould, and B.B. Clarke 1993.
Ecology and Epidemiology of Ectotrophic Root-infecting Fungi Associated with
Patch Diseases of Turfgrass. Pgs 73-76. In Clarke, B.B, and A.B. Gould (ed.).
Turfgrass Patch Diseases Caused by Ectotrophic Root-Infecting Fungi. APS Press,
Landschoot, P.J. 1988. Taxonomy and Pathogencity of
Ectotrophic Fungi with Phialophora Anamorphs from Turfgrasses.
Landschoot, P.J. 2001. Magnaporthe, pp 67-70. In Singleton
L.L., J.D. Mihail, and C.M. Rush (ed.). Methods for Research on Soilborne Phytopathogenic
Fungi. APS Press,
Tredway, L.P. 2005.
First Report of Summer Patch of Creeping Bentgrass Caused by Magnaporthe poae