Magnaporthiopsis species associated with patch diseases of turfgrasses in Australia

Abstract

Isolates of Magnaporthiopsis (Magnaporthaceae, Magnaporthales) were obtained from turfgrass species with patch disease symptoms in sports fields and golf courses in eastern Australia. Patch disease was characterised by plants with root rot, vascular discolouration and dark, ectotrophic mycelium on the root surfaces. Four new species, Magnaporthiopsis dharug , M. gadigal , M. gumbaynggirr and M. yugambeh , are described based on phylogenetic analysis of concatenated partial DNA sequences of the internal transcribed spacer (ITS) region, RNA polymerase II largest subunit ( RPB1 ) and translation elongation factor 1-alpha ( TEF1α ). The descriptions of the fungi include morphological characteristics and host associations. Magnaporthiopsis dharug was isolated from diseased roots of Cynodon dactylon (couch grass, Bermudagrass), Festuca rubra ssp. commutata (Chewing’s fescue) and Poa annua (winter grass); M. gadigal from diseased roots of Pennisetum clandestinum (kikuyu grass); M. gumbaynggirr from diseased roots of C. dactylon ; and M. yugambeh from diseased roots of P. annua . µm wide, forming mycelial strands and curling back at the Conidiophores hyaline, single or branched. Conidiogenous cells hyaline, phialidic, straight or curved, 5–20 x 2–4 µm, narrowed at the base and tapering at the apex. Conidia hyaline, ovoid or cylindrical, mostly straight or slightly curved, 6–10 (–12) x 3–4 µm, apex rounded, base acute, aseptate, hyaline, smooth. Ascomata not observed in culture or on infected material.