Cercosporidium ziziphus sp. nov.- A New foliicolous Hyphomycetes from India

摘要

During a survey, the authors observed a serious leaf blight disease of Ziziphus mauritiana Lamk (Rhamnaceae) from diversified habitats of Jabalpur. The fungus incited infection which started from the marginal portion of the leaf and extended rapidly towards the mid portion. Initially small irregular brown blight symptoms appeared which spread rapidly and became darker in colour. On both surface of the leaf many black, velvety patches were also seen. The causal organism was identified as a species ofCercosporidium. The genus Cercosporidium was erected by Earle (1901) with C. chaetomium as type species. The genus is characterized by immersed mycelium, well-developed stroma. Brown, densely fasiculated conidiophores. Integrated, terminal polyblastic conidiogenous cells. Conidial scars always thickened and conspicuous. Conidia solitary, clavate, obclavate or broadly fusiform, with a conspicuous thickened, hilum, relatively pale brown, 1-7 most septate (Ellis 1971). About 25 species of the genus parasitizing on different hosts have been reported (Ellis 1971, 1976; Brown and Morgan 1976; Deighton 1967; Shrivastava and Mishra 1980; Shrivastava 1974; Kar and Ray, 1984; Kamal et al 1987; Soni et al 1984).